Video distribution traffic accounts for 65-70% of the downstream access network traffic, which has continued to grow in recent years. Advances in video image quality and video compression technologies, coupled with standardization efforts, have led to a significant increase in the maximum required bandwidth per broadcasting channel. Specifically, over the last two decades, the maximum content bitrate has multiplied by approximately 40 times (pre-compression), and 20 times (post-compression) for IPTV, while domestic radio frequency broadcasting has shown the pace of 5 times. At the same time, the future growth of the market is anticipated to be driven not only by the transition to 8K video but also by the integration of Extended Reality (XR) video services that combine 360° 3D video, AI, and digital twin technologies. Taking this opportunity, this paper reviews the trends in video communication technology and the initiatives of Sumitomo Electric Industries, Ltd. The paper also discusses various key indexes required for all-optical and wireless networks connecting cloud computing to homes and workplaces, with a particular focus on what is called the Motion-to-Photon latency, which is essential for realizing immersive and interactive 3D and XR video distribution services, and considers its impact on other key indexes.
Intelligent communication technology is an indispensable part of the infrastructure that supports modern society. In particular, wireless communication systems using high-frequency radio wave carriers have made remarkable progress in the last 30 years. In 2020, 5th-generation services started to realize high-data-rate transmission and low signal latency. The environments in which wireless communication networks operate have expanded to include the open sea and low earth orbit. To date, we have developed many kinds of commercial transmission devices for optical wired and wireless communications. We were the first company in the world to successfully mass produce and commercially ship Gallium Nitride high electron mobility transistors (GaN HEMTs), a key device for cell phone base stations, and have the top market share. This paper describes compound semiconductor devices represented by GaN HEMTs as well as novel crystal and device technology for discontinuous performance enhancement.
Climate change poses a global challenge that necessitates the reduction of carbon dioxide (CO2) emissions. To reduce CO2 emissions from motor vehicles, which are major emission sources, it is important not only to improve vehicle exhaust performance, but also to improve infrastructure such as traffic signal control at intersections to mitigate traffic congestion and energy consumption. A quantitative evaluation of the effects resulting from traffic signal control improvements is essential for their dissemination. Currently, however, there is no well-established method to calculate CO2 emissions of vehicles traveling through intersections. We have developed a CO2 emissions calculation model intended for widespread adoption. This model facilitates the quantitative evaluation of CO2 emissions reduction resulting from traffic signal control improvements.
The global need for pedestrian detectors is increasing to improve traffic safety and efficiency. In order to achieve accurate detection at intersections, the detectors need to be placed in the right locations. However, constructing new poles requires much effort and cost, making it essential to utilize existing poles for widespread deployment of the detectors. Meanwhile, achieving effective pedestrian detection on both far and near sides presents challenges due to the limited sensor viewing angles. Additionally, many sensors are unable to detect pedestrians directly beneath them, thereby restricting the possible installation locations. To overcome these challenges, we have developed a cost-effective radar system with a wide vertical coverage angle, offering improved installation flexibility. This paper introduces the innovative radar and presents experimental results demonstrating its expanded detection area.
In recent years, the convergence of several services and information technologies has revolutionized our daily lives. However, failures in communication infrastructure can have profound consequences, necessitating increased reliability and availability of communication equipment. This paper focuses on our research and development efforts in high-speed Ethernet equipment, specifically addressing MC-LAG (multi-chassis link aggregation) and precision time synchronization in supporting high-quality 5G wireless systems.
To address the rapid increase in data traffic, data centers have increased the number of channels. However, current systems use one semiconductor laser per channel, resulting in higher power consumption and costs due to the increased number of components. To overcome these challenges, a new approach has been proposed, where light from a single laser with high output power is branched to create multiple channels. However, existing telecommunication lasers have reached the limit in achieving high output power with single-mode lasing. Therefore, we have conducted research on 1.3-μm-wavelength InP-based photonic-crystal surface-emitting lasers (PCSELs) as a next-generation semiconductor laser that can achieve both single-mode lasing and high output power. We have demonstrated single-mode operation with a high output power of over 200 mW under continuous-wave conditions at room temperature by using dry-etching and regrowth techniques. In addition, we have achieved a high output power of 4.6 W in short-pulsed operation. These results suggest that PCSELs can be used not only for communications but also for sensing applications.
Sumitomo Electric Industries, Ltd. developed polytetrafluoroethylene (PTFE) porous membranes ahead of the world. In the early 2000s, utilizing the membranes, the Company develop hollow fiber membrane water modules with excellent chemical resistance and strengths. The modules have been widely applied to water purification, sewage treatment, and industrial wastewater treatment around the world. With the increasing demands for the recovery of salt components, we focused on the application of these modules to membrane distillation for the separation of trace components such as salt in seawater and rare-earth elements in water resources, taking advantage of the excellent hydrophobicity of PTFE. This paper reports on the development of a PTFE hollow fiber membrane with superior water pressure resistance and gas permeability, both of which are critical for membrane distillation.
Nissin Ion Equipment Co., Ltd. conducted research on electron transport properties of an argon-ion-implanted amorphous InGaZnO (a-IGZO) film deposited on a glass substrate. The research obtained valuable data on electron concentration and Hall mobility of the film at various depths from the surface. The result shows that the a-IGZO film has a high electron concentration in deep regions compared with an argon plasma-treated a-IGZO film. In addition, the company estimated the argon stopping powers of a-IGZO and the donor level of 0.05-0.1 eV below conduction band bottom energy, which can be applied to resistance control for a-IGZO device processing.
Sumitomo Electric Industries, Ltd. conducted a demonstration of its 2 MW/8 MWh redox flow (RF) battery system for multiple-use applications (MUA) in California, U.S.A. The system was operated within the distribution network to achieve peak shaving and voltage regulation. In the California Independent System Operator market, it simultaneously participated in the energy and ancillary service markets. In addition, the system successfully demonstrated microgrid operations for both black start and seamless transitions, providing MUA for normal and emergency operation to existing residential customers.
As wind turbines grow in size and output capacity, submarine cables transmitting the generated electric power face challenges related to manufacturability, cost, and workability. To overcome these challenges, we have been developing submarine cables without the impervious structure. However, it is difficult to estimate cable life due to the progression of water tree deterioration in flooded cable insulation. To evaluate the cable life of non-impermeable structure, we examined a long-term water tree test method capable of simulating 30 years of operation. By analyzing the time variation of supersaturated moisture content in cable insulation, realistic test periods can be achieved. Future endeavors involve the development of water-tree-resistant cables to withstand long-term operation and high pressures on actual lines, utilizing the test method.
Compound semiconductors have beneficial features that enable high performance devices. In this study, we utilized synchrotron radiation x-ray photoelectron spectroscopy (XPS) techniques to precisely analyze semiconductor surface and interface states, which significantly affect device performance. Regarding gallium nitride high electron mobility transistor (GaN-HEMT) devices for wireless communication, x-ray energy was lowered to 600 eV to study the effect of the O2 ashing process, achieving a probing depth of approximately 2 nm. Combined with photoluminescence analysis, it was confirmed that inappropriate process conditions increased the escape of nitrogen atoms, surface oxidation, and defects in GaN crystals. For the InP-based photodiodes used as detectors in optical communication, the surface potential of InP covered with dielectric films was evaluated, using hard x-ray photoemission spectroscopy with an excitation energy of 7940 eV. Based on our analysis, the film deposition condition was optimized and the leakage current at the interface was successfully reduced to obtain sufficiently high optical sensitivity. This study has demonstrated that timely utilization of synchrotron radiation analysis is extremely effective in shortening the product development of Sumitomo Electric Industries, Ltd.
In recent years, the shift to electric vehicles and the electrification of automotive components are progressing toward the realization of a decarbonized society.The electrification of components has expanded the use of by-wire control, which uses electrical signals to control the target. However, by-wire control has a shortcoming in that it cannot control components if the vehicle power source, such as a lead-acid battery, fails. Sumitomo Wiring Systems, Ltd. and AutoNetworks Technologies, Ltd., both of which are Sumitomo Electric Group companies, have jointly developed an integrated backup battery that enables uninterrupted by-wire control of multiple components even in the event of a vehicle power failure .
In recent years, the advancement of cloud computing, video distribution, and AI has led to a rapid increase in telecommunications traffic and the construction of largescale data centers (DCs). Since optical cables that connect DCs are usually installed in outdoor ducts, the technology for densely installing these cables in a limited duct space is indispensable. In 2017, Sumitomo Electric Industries, Ltd. developed and commercialized an optical cable with the world’s highest fiber count of 6,912. The Company also developed wiring solutions and has contributed to increasing cabling density and improving workability throughout DCs. The Company has recently developed and started sales of a 3,168-fiber-count optical cable with 200 μm fibers and a 2,016-fiber-count optical cable with 250 μm fibers as ultra-high-fiber-count and high-density optical cables suitable for installation in ducts used in Japan and other areas. This paper describes the structure and features of these new cables.
In recent years, semiconductor devices for marine and meteorological applications have become more powerful, and solid-state radars are replacing conventional magnetron radars. Long service life is one of the advantages of solidstate devices. Although magnetrons need to be replaced periodically, semiconductors do not require replacement and thus help reduce radar maintenance costs. It is difficult to observe small objects with magnetron radars due to large frequency fluctuations. In contrast, due to their high-frequency stability, solid-state radars improve observation performance by enabling observation of objects that were difficult to observe in the past. On the other hand, to provide solid-state radars with a detection range equivalent to that of magnetron radars, a plurality of semiconductor devices must be arranged in a row, and their output power needs to be further increased to reduce the required number of devices. We have developed an S-band GaN HEMT with the highest output power of 800 W in the industry. This report describes the features of this new device.
With the rapid growth of renewable energy and electric vehicles (EVs) to realize carbon neutrality, demand for next-generation power semiconductors is expanding. In particular, silicon carbide (SiC) is beginning to be used in some application areas as a new material that achieves higher voltage resistance and less power consumption than silicon. However, the high manufacturing cost is a problem that needs to be solved before it is widely used. In the manufacturing process of SiC wafers and devices, grinding is used to finish wafer surfaces with high efficiency. However, grinding SiC, a hard-brittle material, poses the problems of (1) a high tool consumption rate and (2) high grinding resistance. To solve these problems, the development of a high wear-resistance tool capable of grinding SiC with low cutting resistance has been desired. Against this background, A.L.M.T. Corp. has developed a vitrified bond wheel that achieves both a long tool life and a low grinding resistance at the same time with its proprietary technology for the high-precision dispersion control of submicron structures. A.L.M.T. Corp. began marketing the new grinding tool “Nanomate Masspower” in fiscal year 2022.
In the 5th generation mobile fronthaul (5G-MFH), a wavelength-division-multiplexing (WDM) optical-transmission device is used to efficiently connect many remote units with fewer optical fibers. WDM optical-transmission device for 5G-MFH is required to meet technical requirements such as long-distance transmission and multi-rate operation at low cost. This paper demonstrates a proof-of-concept of WDM optical-transmission device supporting 10/25 Gbps multi-rate operation using signal-compensated optical transceivers equipped with a 10-Gbps-class-bandwidth optical receiver.
Mobile networks are shifting to the fifth-generation mobile communication system (5G) to address the need for increasing data traffic associated with the spread of high-performance mobile terminals and the diversification of services provided. 25 Gbps optical transceivers are used in 5G mobile fronthaul, and wavelength division multiplexing is widely used to expand transmission capacity. We have developed a new optical receiver that can be integrated into a 25 Gbps DWDM transceiver by combining our CAN-type optical receiver and edge-illuminated waveguide APD chip for C-Band. This paper presents the design and performance of the new optical receiver.
The development of various IoT applications is accelerating data traffic, and it is anticipated that a data rate of more than 10 Tb/s will be required by 2030. On the other hand, conventional single-material photonic device technologies seem to have limitations to achieve both high-speed operation and low power consumption for 10 Tb/s-class data transmission. To overcome this challenge, heterogeneous integration, which combines the advantages of III-V compound semiconductors for high-speed and high-efficiency operation and Si photonics for high-density integration through device miniaturization, is expected as one of the promising approaches. This paper reports wavelength tunable lasers using heterogeneous integration.
To cope with the rapid increase in data traffic, 400 Gbit/s optical transceivers have been introduced in data center optical communication systems, requiring high-performance electro-absorption modulator integrated lasers (EMLs). We have developed four EMLs with center wavelengths of 1271, 1291, 1311, and 1331 nm, which meet the specifications for 400 Gbit/s optical transceivers. This paper describes the design and typical characteristics of these new EMLs.
Co-packaged optics (CPO) switches are attracting attention for their ability to reduce power consumption by integrating electrical and optical functions in a single device using silicon photonics (SiPh) technology. By placing the SiPh chip close to the switch ASIC and shortening the electrical interconnection distance, power consumption can be reduced while maintaining the data rate. For optical coupling with a surface coupling type CPO module in the limited space, new optical interconnection components with a low profile, high density, low loss, and high reliability are necessary. For this purpose, we demonstrated a 72-fiber, two-dimensional optical fiber array with a 90-degree bend (2D-FBGE (FlexBeamGuidE)). We developed a stress-free bending technique of polarization-maintaining fiber (PMF). The stress-free bent PMF shows a small radius (R = 2.5 mm), low loss, and high polarization-maintaining characteristics. By combining 90-degree bent optical fibers with a two-dimensional hole array, we have fabricated the 2D-FBGE with a low profile of 5.5 mm, high density of 24 fibers/mm, low insertion loss of less than 0.5 dB, and high polarization-maintaining characteristics of more than 20 dB. Thus, 2D-FBGE offers robust, space-efficient, and scalable fiber coupling applications for surface coupling type CPO modules.
The transmission capacity of a single submarine cable has been increasing to meet the growing demand for global data traffic, requiring the continuous advancement of optical transmission systems and optical fibers. This paper discusses the submarine fiber that provides the best performance and cost efficiency for the overall system. We found that submarine fibers having a medium core area of 110 to 130 µm2 and attenuation as low as 0.15 dB/km or less are the most preferable for the current several-hundred tera b/s cables based on digital coherent technology. The paper also discusses the prospects for optical fibers with smaller outer diameters and multi-core fibers for the realization of 1 Pb/s and beyond cable by increasing the number of optical fibers installed in the cable.
The PureAdvance series includes optical fibers with low attenuation of 0.17 dB/km or less and an enlarged effective core areas of 110 or 125 μm2. These fibers are fully compliant with Recommendation ITU-T G.654.E, and suitable for terrestrial long-haul optical transmission systems. Sumitomo Electric Industries, Ltd. has improved the attenuation of PureAdvance to 0.16 dB/km or lower (typically 0.156 dB/km), and started the commercial supply. With the ultra-low attenuation, transmission performances of terrestrial long-haul optical links can be further improved, enabling high-speed optical transmission at 400 Gb/s and beyond. These fibers will contribute to the realization of high-capacity optical communication in terrestrial long-haul networks.
This paper describes newly designed ultra-high-density (UHD) microduct optic cables that are installed into microducts using air-blown technique in order to efficiently build optical transmission capacity in data centers and other facilities. Our microduct cables range from 96-fiber to 864-fiber cables, including 288-fiber cable with flame retardant properties. The UHD microduct cables employ Freeform Ribbon, in which fibers meet and split out repetitively in longitudinal and transverse directions, allowing high fiber density and efficient fusion splicing. In order to enhance the cable-blowing performance, we choose a thin and lightweight cable design with low friction jacket material. These microduct fiber optic cables can be used in various environments, contributing to the efficient and flexible network designs suited to data centers and other customer needs.
This paper describes a new pre-connectorized ultra-high-fiber-count (UHFC) optical fiber cable that has been developed to reduce installation time in data centers. The cable is made of a thin 3456-fiber optical cable consisting of 200 µm Freeform Ribbon fibers and a slotted core. At both ends of the cable, 24-fiber multi-fiber push-on (MPO) connectors are assembled and precisely sealed with a protection sleeve optimally designed for tensile and other mechanical properties. The result of a cable pulling test simulating actual installation was confirmed that the developed cable achieves the same number of optical fibers accommodated in the duct as conventional non-connectorized cables. This cable enables a reduction of connection time by using the MPO connectors instead of mass fusion splicing, and is expected to reduce installation time by about 40% compared to conventional cables.
In multicore fiber (MCF) transmission, low inter-core crosstalk (XT) is crucial to suppress signal quality degradation. This study reveals that the dependence of the XT on fiber bending radius can be evaluated from the longitudinal changes in the bending radius of spooled MCFs with multi-channel OTDR. Using multi-channel OTDR, we also developed a measurement method for backscattered XT, which needs to be considered for bidirectional MCF transmission. With the developed method, we verified the validity of the theoretical prediction of the fiber length dependence of the backscattered XT and clarified the effect of fanout on the bidirectional XT. Our study shows the applicability of multi-channel OTDR for characterizing longitudinal XT change in MCFs and the preferable characteristics of bidirectional transmission in MCF.
Next-generation transmission systems using multi-core fiber (MCF) for data center applications require fan-in/fan-out (FIFO) devices with low insertion loss (IL) and high return loss (RL). A fiber bundle FIFO can achieve low IL and high RL by high-precision core eccentricity control of the fiber bundle and physical contact connection between the MCF and the fiber bundle. Although our FIFO is designed to allow only rotational alignment between the MCF and the bundle, the optical characteristics of the fabricated FIFO devices achieved IL of less than 0.3 dB and RL of more than 50 dB.
The increased transmission loss of optical communication cables in low-temperature environments has been a longstanding issue. However, the mechanism of the loss is still largely unknown. We have developed a technique for evaluating the shape of actual optical cable samples in a low-temperature environment, which was one of the biggest obstacles to elucidating the mechanism. The proprietary technologies include the method to perform low-temperature observation with a simple retrofit mechanism for existing general x-ray computed tomography (XCT) systems and the method for accurately extracting the shape of individual fibers from an indistinct XCT image and quantifying them three-dimensionally. In particular, the latter technology applies not only to optical cables but also to a wide range of cable products, contributing in many ways to the digital transformation promotion of cable product design using big data. This paper introduces an effort to conduct cable evaluation from the viewpoints of both actual measurement and computer-aided engineering, using the shape evaluation of multi-core optical cables in a low-temperature environment as an example.
Millimeter-wave GaN HEMTs are expected to be used in higher-capacity wireless communications, but the large nonlinear components such as short-channel effects, have challenges in creating the large-signal models that are essential for amplifier fabrication. In this report, we have developed an innovative model that an artificial neural network (ANN) is applied only to the current source to avoid over-fitting issues. To create this model, pulsed I-Vs/S-parameters measurement data up to 120 GHz were used. The proposed model is the first to demonstrate large-signal power performances at 71 GHz in high accuracy.
High-efficiency power amplifiers generate little heat and operate with a small heat dissipation function, making them effective in reducing the size, weight, and cost of communication devices. Since many amplifiers are used in massive multiple-input multiple-output (MIMO), higher efficiency amplifiers are required, and those based on gallium nitride high electron mobility transistors (GaN HEMTs) are becoming popular particularly for cell phone base station applications. On the other hand, load modulation is attracting attention as an amplifier technology for improving modulation efficiency. Among them, Outphasing amplifiers are known to achieve higher modulation efficiency than conventional Doherty amplifiers. In this study, we conducted a design prototype evaluation of an Outphasing amplifier using our GaN HEMTs. The result confirmed that the higher efficiency of the amplifier reduces power consumption by 1.1 W per amplifier compared to the conventional Doherty amplifier configuration. In a 64 transmitters Massive MIMO base station, a power reduction of 70.4 W is achieved, contributing to the miniaturization of the base station.
We have developed a high-output, high-efficiency internally matched power amplifier for satellites using gallium nitride high electron mobility transistor (GaN HEMT). Today's wireless communication technology has become indispensable in our lives, not only for Internet and mobile phone communications, but also for electronic payment. Therefore, it has become an indispensable in our lives. Therefore, global information network is growing and the need for satellite communications is increasing as these are less susceptible to natural disasters. The newly developed power amplifier achieves an output power of 100 W and power added efficiency of 60% under CW operation conditions in the C-band (f = 3.7 to 4.2 GHz), the main frequency for satellite communications. The GaN chip used in the development has a confirmed long-term reliability. In terms of both the performance and the reliability, the industry-leading device.
In recent years, AI-based video analysis has been widely used in various fields. Demand for higher definition and wider area viewing has led to the development of cameras with higher resolutions such as 4K and 8K. As a result, the cost of video data transmission, storage, and analysis has increased significantly. In response to this, we have developed a prototype AI-based video processing technology (AVP) that can significantly reduce the amount of video compression data and cloud AI computation cost after transmission. In a field test conducted at a factory, AVP reduced the average bit rate by 92.2% compared to conventional video compression technology, while reducing the AI computation cost on the cloud side, enabling highly accurate analysis of workers' movement flow using high-resolution video.
Quantum computing is attracting attention as a technology for solving complex combinatorial optimization problems at high speed. We have been selling delivery planning systems, one of the business support tools for logistics companies, for 20 years and have been conducting research and development of related technologies. The delivery planning systems have a function to calculate efficient delivery routes with low transportation and delivery costs, but it requires complex optimization calculations. With the aim of applying quantum computing to this optimization computation, we are formulating, implementing, and evaluating the performance required for this purpose. In this paper, we report the findings of the validation of the formulation by comparing the results obtained using the Ising machine and conventional computers.
In recent years, the importance of improving the efficiency of power devices used for electric power control has been increasing. Silicon carbide (SiC) is a wide bandgap semiconductor with superior material properties such as high breakdown electric field and high thermal conductivity. Commercialization of SiC MOSFET (metal-oxide-semiconductor field effect transistor) has already begun, and the market size is expected to expand further in the future although Silicon (Si) is mainly used for power devices currently. We have been developing a low on-resistance “V-groove” trench MOSFET (VMOSFET), which uses the patented crystal face as the channel region. In addition to the transistor technology, we have been developing the full SiC modules with the VMOSFET. This report introduces the feature, the electrical characteristics, and the reliability test results of the full SiC power module (1200 V 400 A). The module package has compatibility with Silicon (Si) power module package and is designed for easy replacement for existing users of Si power modules.
Since 1993, Sumitomo Electric Industries, Ltd. has been manufacturing polyimide fuser rollers, important parts for laser beam printers (LBPs). In recent years, we have developed a high thermo-conductive fuser roller applicable to high-speed printing systems. It uses a composite material that combines carbon nanofiber with high thermal conductivity and tough polyimide resin. Carbon nanofiber is an excellent thermal conductor, but is subject to regulation due to the high risk of residuals when taken into the body. As an alternative to carbon nanofiber, we have developed a new fuser roller using graphite filler, which is also a carbon-based filler.
With the recent miniaturization of electronic equipment, there is an increasing demand for high-density wiring in flexible printed circuits (FPC). We have developed a circuit formation technology using a semi-additive process that uses fine-pitch, high-aspect plating. The plating technology has enabled us to establish a manufacturing method for the fine-pitch FPCs that cannot be realized by conventional etching-based circuit formation processes. By applying this technology, mass production of actuator coils for image stabilization of high-performance smartphone cameras has been realized. This paper reports on the circuit formation technology using the semi-additive method and examples of its application to actuator coils, and introduces the latest developments.
In order to achieve carbon neutrality, there is a growing trend to use renewable energy as the main power source. However, with an increase in the use of renewable energy, the power system has become congested, making it difficult to connect other new power sources. To solve this problem, Japanese Connect and Manage is being developed to review conventional methods and address power system congestion. Moreover, the dynamic rating is being considered a new operational technology. To realize these concepts, a real-time monitoring system is needed to monitor the conditions of overhead transmission lines and the environment around transmission towers. This system will play an important role as renewable energy will be introduced in large quantities in the future. We have been developing an overhead transmission line monitoring system for the large-scale introduction of renewable energy. This paper introduces the features of our developed system and equipment.
Sumitomo Electric Toyama Co. Ltd. is aiming to apply Celmet, a porous metal product, as a current collector for solid oxide fuel cells (SOFC). NiCo Celmet is particularly suitable for cathode current collectors as it forms conductive oxides in a high-temperature and high-oxidant atmosphere. We reported that fuel cells using the NiCo Celmet exhibit high power density even without gas flow channels in the interconnector because of its high gas diffusivity. In this study, to elucidate the mechanism of high power density, we investigated the influence on DC resistance by applying Celmet as a current collector. We clarified that the contactability between the cell and Celmet is improved by shaping Celmet along the warp of the cell. Moreover, we found that NiCo Celmet can maintain good contactability as its oxidation expansion applies pressure from the inside of the stack.
Due to the increasing demand for carbon neutrality and resource saving, there is a demand for smaller and lighter spring products used in automobile engines, clutches, and other parts. As a result, it is necessary to increase the strength of spring materials. Conventionally, materials have been developed with the policy of increasing fatigue strength equating to increasing hardness. Spring materials, which require the highest fatigue strength among all metal materials, have reached a plateau, and a new approach that considers the environment in which the materials are used is becoming necessary. This paper describes the performance of a newly designed high-strength oil-tempered wire product.
Polyethylene (PE) is one of the polymers widely used in industry. PE is frequently used as a processing material because it is easily cross-linked by electron beam irradiation and its heat resistance is expected to be improved. This paper describes the mechanism of electron beam crosslinking of PE and its effect on PE. The property changes observed in cross-linked PE are also presented.
We have developed a new analysis technology to accurately calculate the bending shape and bending load of multi-core composite cables installed in the undercarriage of automobiles. The multi-core composite cables are made by bundling multiple electric wires (core wires) and integrating them. They connect the electric parking brake, wheel speed sensor, etc. arranged in the wheel to the vehicle body-side unit, and are responsible for power supply and signal transmission. Demand for the cables is increasing with the electrification of automobiles and technical development of advanced driver-assistance systems (ADAS). The appealing point of the cable is the bending resistance, which prevents the conductor from breaking even when it is repeatedly bent due to the vertical movement of the wheel during traveling. In the past, the cable design was performed after determining the actual vehicle layout shape using CAD, but the calculation accuracy of the bending load was low, and the cable design had to be adjusted during prototyping and evaluation, causing the development period to be prolonged. With the newly developed analysis technology, the bending shape and bending load can be accurately calculated when both ends of the cable are fixed at a predetermined position and angle, thereby streamlining development.
The Mosquito method, a polymer optical waveguide fabrication method invented by Professor Ishigure at Keio University, enables the three-dimensional (3D) formation of core patterns in cladding using a commercially available micro dispenser and a multi-axis syringe-scanning robot. This fabrication method is expected to be used to realize devices required for 3D waveguides such as Fan-in/Fan-out (FIFO) devices, which are essential for the introduction of multicore fibers (MCF). On the other hand, prior studies have mainly examined multimode waveguides, and several issues need to be solved for making single-mode devices. In particular, the core shape tends to deteriorate from circular due to monomer flow caused by needle scanning in the cladding, which is a factor that increases the connection loss with the optical fiber. This paper presents a theoretical and experimental study on the fabrication of single-mode waveguides by the Mosquito method and the formation of circular cores using the method to reduce connection loss with single-mode optical fibers.
In the construction of 5th generation (5G) mobile communication systems, the transmission speed at the mobile fronthaul (MFH) section is about 2.5 times faster than that of conventional systems. As the signal speed increases, there is a problem of shortening the optical transmission distance due to the effect of wavelength dispersion in single-mode fibers. As a measure to extend the optical transmission distance, we have developed a media converter type optical repeater that converts the wavelength to the 1.3 µm band, where the effect of wavelength dispersion is minimized. The repeater combines waveform generation processing with electric circuits to compensate the transmission characteristics and can be applied to transmission lines up to 30 km. This paper describes the 25 Gbps optical repeater.
A digital coherent optical transmission technology has been deployed in not only long-haul and metro networks but also data center networks. Therefore, there is an increasing demand for a coherent module that can be incorporated in small-sized optical transceivers and realize high-speed and high-capacity transmission. Considering the demand, the Optical Internetworking Forum has standardized an integrated coherent transmit-receive optical sub assembly (IC-TROSA) module in August 2019. This paper presents an IC-TROSA type-2 module that integrates a tunable laser for 800 Gbit/s applications.
Electronic devices using oxide semiconductor In-Ga-Zn-O (IGZO) are attracting attention as next-generation flat panel displays. In order to apply ion implantation technique to IGZO films, Nissin Ion Equipment Co., Ltd. and Nissin Electric Co., Ltd. performed conventional B+ implantation in IGZO films and investigated their optical or electrical properties. The results show that the resistance control of IGZO films by B+ implantation is useful for the IGZO electronic devices, especially for reducing the resistance in the source and drain region of the IGZO thin-film transistors.
Development of new catalysts is progressing rapidly toward the construction of chemical processes with lower environmental impact. Celmet is a porous metal with a three-dimensional network structure having over 90% of porosity, and therefore is expected to be used as a support material for catalysts with low pressure loss and high deformability. The Celmet support also has the advantage that it can be heated directly by an electrical heating means. This paper revealed that a catalyst coated with CeO2 powder loaded with fine Ru particles on Ni Celmet exhibited practical propane steam reforming performance comparable to commercially available Ru spherical catalysts. Furthermore, NiCr Celmet electrically heated at 500°C was estimated to have long-term durability based on the time-course change in electrical resistance, suggesting that it can contribute to the construction of compact and energy-efficient reactors.
Electric wires and conductive spring wires require high strength to withstand repeated bending and maintain high contact pressure. However, the higher the strength of general-purpose copper compound metals, the lower their conductivity. To overcome this challenge, we have developed a new composite wire with a stainless steel coating on a copper core wire by making full use of our wire drawing and heat treatment technologies. This new wire has higher strength and conductivity than beryllium-copper alloys, the strongest of the copper alloys, and is strong against bending and twisting outside stainless steel. This paper presents the results of an evaluation of its resistance to settling and repeated bending, assuming that the wire will be used as a conductive spring or electric wire.
Exotic alloys such as Ni-based alloys, cobalt (Co)-based alloys, and titanium (Ti) alloys are widely used for equipment and parts in aerospace and automotive industries due to their superior resistance against heat and corrosion. There has been growing demand for tools for machining these alloys. When cutting exotic alloys, the workpiece material is likely to adhere onto the cutting edge of a tool, resulting in a sudden fracture of the cutting edge of the tool. The tool life is significantly shorter than that of tools for cutting general steel. Thus, demand for cutting tools with stable performance and long tool life has been increasing. The newly developed ACS2500 and ACS3000 are designed to improve wear resistance and fracture resistance by applying a newly developed physical vapor deposition (PVD) coating and special cemented carbide substrate. These coated carbide grades help reduce cutting edge replacement frequency and tool consumption by extending tool life, thus contributing to the reduction of machining costs.
In recent years, computer-aided engineering (CAE) simulation technology has become indispensable in the manufacturing industry as a part of developing products and optimizing process conditions. CAE supports manufacturing processes and product functions based on physical theories. It stimulates the imaginations of designers and production engineers by visualizing invisible phenomena, such as electromagnetic waves, heat, and stress, and connects to the development of new products and improvements of processes. Furthermore, these days more customers request CAE analysis results in addition to experimental results in adopting new products or manufacturing processes. In order to obtain useful and accurate CAE analysis results under these circumstances, it is necessary to develop advanced CAE technology reproducing experimental results, and high-speed calculation servers. In this work, we have realized CAE analysis that could not be handled previously, by increasing the calculation efficiency and functional performance of the calculation servers. This article gives an introduction to the details of these calculations in various analytical fields.
There is a rapidly expanding market for industrial solutions to improve productivity and safety by transmitting all kinds of information in factories and cities to the cloud at high speed and with low latency through 5th generation mobile communication systems and analyzing the information using AI. We have developed an industrial 5G terminal that can be used in both public 5G networks, which are deployed by mobile carriers, and local 5G networks, which are built by companies and local governments within a limited area. This 5G terminal has an edge computing function and ease of installation of applications that meet user requirements. The combination of edge computing in this 5G terminal and cloud computing in a cloud server makes it possible to realize optimal solutions that meet user requirements.
Sumiden Communication Engineering Co., Ltd. has been involved in the nursing care service industry through the provision of the nursing care service billing system “Care Time,” which calculates service charges based on helpers’ service records and bills payers, for about 20 years. We have recently developed a WEB system that can share data with the nursing care service billing system and started offering it to nursing care service companies as a subscription service.
As fluorescent lamps installed in cable tunnels (tunnels for laying communication cables) are being replaced with LED lights, we have been selling immersion-proof LED light fixtures with an IP67 (dustproof and immersion-proof) rating since 2013. However, their use in narrow spaces has been limited due to their external dimensions. This time, we have released compact and easy-to-install LED light fixtures that can be installed in narrow spaces while maintaining the advantages of our conventional products.
Currently, most power cables are XLPE cables, which use crosslinked polyethylene (XLPE) for insulation. XLPE has excellent heat resistance due to its crosslinks, but it shows no fluidity with heat and its material recovery is difficult. In addition, the longer the cable to be produced, the longer the lead time may be, because manufacturing XLPE cables requires a crosslinking reaction process to form a network structure and a drying process to exhaust by-product gases from the reaction. Against this backdrop, we have developed environmentally friendly non-crosslinked insulated power cables that can contribute to improving productivity.
The market for industrial robots is rapidly expanding due to labor shortages, cost reductions, and productivity improvements in industry, and the demand for precision bearings (linear guides and ball screws) is growing. Profile grinding is often used to grind the rolling surfaces of the main parts of bearings because it requires particularly high productivity. Profile precision depends on the diamond rotary dresser (RD) that trues and dresses the profile grinding wheels. To further enhance efficiency, conventional and general grinding wheels have been replaced by rigid wheels, which use the most rigid material after diamond and enable high-speed grinding. In step with this, the development of profile RDs with high abrasion resistance has been required. In response to requests from the bearing industry, we have developed and begun marketing a new RD for rigid wheels, such as vitrified cubic boron nitride (CBN) wheels, using our original plating technique.
A milling cutter is a cutting tool with a cutting edge on the periphery, end face, or side face. Various kinds of parts are machined by revolving the cutter. Milling cutters with indexable inserts are widely used today for various types of machining. Recent performance improvement of machine tools is increasing the need for tools specialized in high-efficient machining in the automotive, aerospace, ship building, industrial machinery, die-mold, and other sectors to improve productivity. Environmentally friendly machining has also become a focus of attention as a part of CO2 emissions reduction activities to achieve a decarbonized society. Sumitomo Electric Industries, Ltd. has recently developed the SEC-Sumi Dual Mill DMSW series (DMSW), which enables more efficient machining and contributes to increasing productivity and saving energy.
Efforts toward a Zero-Carbon society to curb global warming have become a major trend worldwide. Back in October 2020, the Japanese government proclaimed the target of achieving Carbon-Neutral by 2050, referred in “Green Growth Strategy,” with a policy to make concerted efforts on the development of renewables and hydrogen energy sources, namely “carbon neutral innovation,” with aims to strengthen the competitiveness of Japanese industry. In addition, a “Green Innovation Funding” was founded to promote it.
In an effort to create a decarbonized society, Japan, Europe, and the United States are shifting their main energy sources from fossil fuels to renewable energy sources such as solar power. However, the output of renewable energy sources fluctuates depending on weather conditions, making it difficult to provide a stable supply of electricity. As a solution to this problem, efforts are being made to introduce distributed power sources such as small- and medium-scale solar power generators and storage batteries on the consumer side to level out the output fluctuations of renewable energy. As renewable energies are introduced in large quantities in the future, energy management systems will play an important role in integrating distributed power sources and operating them stably and efficiently. This paper discusses a next-generation energy management system that organically links distributed power sources and controls them in an integrated manner. We first discuss the technical challenges of integrated management of distributed power sources, and then summarize the prior technological trends toward the solution of these challenges. Finally, the features and application areas of our energy management system “sEMSA-μGrid” are explained.
With efforts to realize a carbon-neutral and sustainable society accelerating on a global scale, Nissin Electric Co.,Ltd. has launched a new medium- to long-term plan, VISION 2025, aiming to contribute to “the realization of a sustainable global environment and a society in which anyone can play an active role” through six growth strategies. Among them, Smart Power Supply Systems (SPSS) are a solution business that supports our growth strategies in the environment and energy fields. This paper introduces the recent efforts for SPSS.
With the spread of solar power generation as a renewable energy source and the deregulation of electricity, attention has been focused on the realization of energy management utilizing IoT, such as local production and local consumption of energy and the development of storage batteries and EV-based power storage. To solve problems in the energy field using IoT technology, Nissin Systems Co., Ltd. primarily provides gateway devices, software, and services using cloud systems to develop business for general consumers. This paper introduces the technical contents of the area aggregation cloud system built in the island-and-islets-type Smart Community Actual Positive Business in Miyakojima, Okinawa.
It is very important to understand the current that flows in a polymer material when a voltage is applied to it because it reflects the physical phenomena that occur in the material. To measure and analyze the phenomena, we have been studying the direct current integrated charge (Q(t)) method in which integrated currents are measured and analyzed as the amount of charge. Here, the ratio of the charge immediately after the application of square wave voltage Q(0) and the charge tm after the application of voltage Q(tm) is introduced as the charge ratio Rc=Q(tm)/Q(0). The physical meaning of Rc is discussed, and it is shown that Rc can be expressed by a simple equation between the relaxation time of the material and the measured time of the material in an ideal state of electrical conduction. These relations were used to analyze the conductive state of cross-linked polyethylene.
The reduction of greenhouse gases has become an urgent issue globally, and thus the introduction of offshore wind power generation is progressing. A higher voltage requirement (at 66 kV-class) for submarine cables is due to increased power output from wind turbines and structural changes to the wet design that omits the water-impervious layer to improve manufacturability, cost, and workability. However, removing the water-impervious layer increases the risk of breakdowns due to insulation deterioration namely “water trees.” A study has been carried out on water tree retardant insulation and it has been confirmed that the new submarine cables meet the standard (CIGRE TB722) established in 2018 even with the omission of the water impervious layer. Considerations were made for a water tree retardant insulation that can be used under high voltage exceeding 66 kV-class in order to cope with long-term operation and higher power output from wind turbines in the future. This development will contribute to the promotion of offshore wind power generation.
The cross-linked polyethylene (XLPE) cable has been used for DC transmission lines. We have been developing the DC XLPE cable for a few decades, and proved its quality and reliability through the research and development process. In 2012, we delivered the cable to Electric Power Development Co., Ltd. for its DC 250 kV transmission project, making it the world's highest voltage DC XLPE cable at that time and the first one to be applied to a line commute converter system. Following the project, we successfully completed two new projects: the 250 kV transmission project of Hokkaido Electric Power Co., Inc. and the 400 kV transmission project of NEMO Link Ltd. Our DC XLPE cable has an allowable continuous conductor temperature of 90 degrees Celsius, which is equivalent to the conventional AC XLPE cable, and withstands polarity reversal of voltage. This cable will meet the various needs of DC transmission that are expected to increase in the future.
Stable electric power supply is vital for today’s society. However, line faults still occur because of lightning strikes or other causes. Line faults must be located and repaired as quickly as possible. In particular, in the case of line faults where overhead and underground transmission lines are connected, recovery measures differ by location. Thus, locating the line fault and determining whether the line fault is on the overhead or underground transmission lines is critical for early recovery. We have developed the Fault Sector System that identify line faults based on the information from current sensors installed on overhead ground wires and underground power cables. This system has been fully implemented in electric power companies. This paper reports on the outline of the system.
In the maintenance of underground transmission lines, there is a need to shift from time-based maintenance, where maintenance is performed manually and periodically, to more advanced condition-based maintenance, where maintenance is performed efficiently when necessary, through the promotion of digital transformation using IoT and AI to achieve smart maintenance. One of the challenges in realizing IoT has been the difficulty in developing an inexpensive, safe, and reliable communication method to acquire sensor information about cables installed in conduits, which account for the majority of underground power transmission facilities. This paper describes the development of a system that collects sensor information and camera images using a 66-kV XLPE cable installed in a conduit manhole, in collaboration with TEPCO Power Grid, Inc.
The span length of an overhead transmission line crossing a strait can exceed 1000 m. In order to suppress the sag of the line, higher strength conductors are required than those used for the wland part. High-strength thermal-resistant aluminum alloy wires with a conductivity of 55% IACS are used for conductors passing through such spans, but their conductivity is lower than that of the wires used in the land part (60% IACS), which limits the transmission capacity. This time, in collaboration with J-Power Transmission Network Co., Ltd., we have developed a new type of high-strength thermal-resistant aluminum wire with an improved conductivity of 58% IACS. This paper reports on the development of technology and examples of new conductor design.
Nissin Electric Co.,Ltd. has developed a technology that uses artificial intelligence to predict the chemical oxygen demand (COD), total nitrogen content (TN), and total phosphorus content (TP) in discharged water two hours after measurement, based on the past measurement data accumulated in the monitoring and control equipment of sewage treatment plants. The technology enables maintenance staff to change the operation of sewage treatment before the water quality deteriorates. This prevents the deterioration of the water quality without effort.
Many motor vehicle manufacturers around the world are shifting from the vehicle sales business to the mobility service business. Participating in the connected business area, the Information Network R&D Center is developing a prototype solution for managing and analyzing in-vehicle devices, in-vehicle software, and in-vehicle sensor data together with the Systems & Electronics Division, CAS-EV Development Promotion Division, and AutoNetworks Technologies, Ltd. This paper introduces our efforts in commercializing fleet management systems for connected vehicle in the future.
Traffic congestion occurs at intersections with fixed time signal control without vehicle detection sensors. This is partly because the signal control parameters have failed to respond to changes in traffic demand. Therefore, we have developed a technique to detect and analyze congested intersections where the situation will be improved by retiming the signal control parameters. Using this technique, we confirmed that it is possible to identify congested intersections without vehicle detection sensors and analyze traffic conditions.
With the launch of 5G services and AI applications, the amount of data flowing into networks is increasing. While network devices are required to have higher bandwidth, they are also required to be smaller and denser due to limited installation space in urban areas. We have developed a small 200G OTN optical transmission device to improve the accommodation efficiency. This device uses digital coherent optics to achieve long-distance and high-density transmission through wavelength multiplexing. This paper reports the transmission distance and the traffic restoration time in line protection using the device.
This paper describes the structure, characteristics, and workability of the small-diameter 6912-fiber-count cable with 200 μm Freeform Ribbon fibers for data center applications. In the 200 μm Freeform Ribbon, fibers meet and split out in turns in a longitudinal and transverse direction, thus allowing high fiber density and mass fusion splicing. Having a non-preferential bend axis, the cable can easily be installed in space-constrained areas. By optimizing the structure and improving the micro-bend resistance of the fiber, we have realized a reduction of the cable cross-sectional area by about 34% compared to the conventional cables. Furthermore, while the conventional cable was pulled into a 2-inch pipeline, the small diameter 6912-fiber-count cable can be applied to a 1.5-inch pipeline, with the same pull-in tension as before.
Three types of individual core pump multicore erbium-doped optical fiber amplifiers with different core coupling have been demonstrated. These amplifiers showed better power consumption efficiency, such as 24% for a coupled 4-core optical fiber amplifier. Crosstalk is an important parameter in uncoupled multicore optical fiber transmission. The crosstalk of the uncoupled 4-core optical fiber amplifier is -43 dB, which is comparable to the lowest crosstalk in previously reported multicore optical fiber amplifiers. The mode-dependent loss, an important parameter in coupled multicore optical fiber transmission, corresponds to the core-dependent gain of uncoupled multicore optical fiber amplifiers and weakly coupled optical fiber amplifiers. The core-dependent gain of the weakly coupled 7-core optical amplifier is 0.52 dB, which is comparable to the smallest mode-dependent loss in previously reported multicore optical fiber amplifiers.
To address the needs for increasing data traffic resulting from the widespread use of advanced mobile terminals and the diversification of internet-based services, over 100-Gbit/s optical transceivers have been used in optical communication systems of data centers. Furthermore, there has been a strong demand for extended reach connection between data centers. We have developed a new compact receiver with a semiconductor optical amplifier for 40 km/80 km transmission. This paper describes the design and typical characteristics of the new optical receiver.
Optical receivers with intensity-modulation direct detection strongly require ultra-high-speed and high-responsivity performance to 100 GBaud-class toward the next-generation 800 Gbit/s data center networks. This paper demonstrates wide-bandwidth and high-responsivity performance of the InP-based waveguide photodetector integrated with the spot size converter having no polarization dependence. We also introduce the waveguide avalanche photodiodes.
Exotic alloys, such as nickel alloys, cobalt alloys, and titanium alloys, are widely used for equipment and parts in the aircraft and automotive industries due to their superior heat and corrosion resistance. There has been a growing demand for the machining tools for these alloys. We released the AC5015S and AC5025S for exotic alloy turning, which use the new physical vapor deposition (PVD) coating technology. Meanwhile, there is a strong need for cutting tools that enable high-efficiency machining. To satisfy these demands, we have developed a new exotic alloy turning carbide grade, AC5005S, which shows excellent wear resistance, plastic deformation resistance, and fracture resistance in high efficient machining. Together with the existing AC5000S series, the new AC5005S will reduce machining costs in a wide range of exotic alloys turning operation.
Analysis of the structure and composition of materials is essential for product development and quality improvement. The objects of analysis may include semiconductor substrates, plating, and resin surface finishes, specifically the depth profile of chemical species near the surface, and many other determinants of product characteristics. Nondestructive evaluation of depth profiles for individual chemical species in unknown samples is difficult with existing analytical methods. Thus, to meet this need, we have developed a new data analysis technique for angle-resolved X-ray photoelectron spectroscopy (ARXPS), dubbed the maximum smoothness method (MSM). In combination with obtaining depth information using the three XPS systems available to our company, MSM analysis enables nondestructive evaluation of profiles at wide depth ranges. Here, we describe MSM analysis using the three XPS systems and nondestructive depth profile evaluation for a wide range of products.
In recent years, the electrification of automobile components/parts has been progressing with the aim of shifting to electric vehicles to realize a decarbonized society. Electrification will expand the use of by-wire control, which allows devices to be controlled by electrical signals; however, a control failure occurs if the vehicle power source, such as a lead-acid battery, becomes inoperative. Sumitomo Wiring Systems, Ltd. and AutoNetworks Technologies, Ltd. of the Sumitomo Electric Group have developed an integrated x-by-wire backup battery designed for uninterrupted by-wire control of more than one device even in the event of a vehicle power failure. The product was adopted by Toyota Motor Corporation for their Lexus NX launched in 2021.
In recent years, there has been an increase in data processing capacity due to the widespread use of high-per-formance PCs and automatic driving systems and the communication of high-quality video data by smartphones and other devices. Therefore, printed circuit boards (PCBs) used in these products are required to be more heat resis-tant and durable than ever before. To improve heat resis-tance and durability, there has been progress in improve-ment and increase in the content of heat-resistant and heat-dissipating fillers, super-multilayering of boards, and increase in the thickness of boards, all of which make it more difficult to drill holes in boards. Specifically, it leads to increased drill wear and consequent degradation of hole position accuracy, resulting in decreased board reliability due to degraded hole accuracy and hole inner wall quality.
In recent years, serious accidents caused by wrong-way driving on expressways have become a problem. Expressway administrators have taken measures to prevent vehicles from running the wrong way particularly at entrances and exits, but no effective measures have been taken on the main lanes. We have developed software that detects wrong-way driving vehicles using the loop-type vehicle detectors already installed on expressways. Further, we have developed a system that notifies the expressway control center when a wrong-way driving vehicle is detected. In this paper, we present the false detection suppression algorism that has been field tested to improve accuracy, and report on the results of accuracy evaluation of the detection system.
Due to the rapid growth of internet traffic, the transmission capacity of optical coherent communication is about to reach 800 Gbit/s. Photodetectors for coherent receivers are required to have three key features: wide frequency bandwidth to support 100 GBaud operations, high responsivity to mitigate the power consumption of local oscillators, and multifunctional integration to reduce footprint and cost. We have developed a wide-bandwidth and high-sensitivity InP-based optical mixer-integrated photodetector that can be installed in an 800 Gbit/s coherent receiver, and a multifunctional integrated photodetector that enables the downsizing and cost reduction of coherent receivers.
The rapid growth of optical network traffic has dramatically increased the demands for high-density optical interconnects in data centers. To realize high-density multi-channel optical connections with easy handling, single-fiber connectors with multi-core fibers (MCFs) are expected. In this paper, we present a new type of LC-interface MCF connector. The connector has passed the Telcordia GR-326-CORE reliability test and achieved low insertion loss compatible with IEC 61753-1 Grade B for low-loss SMF connectors.
We have developed “PureAdvance,” a low-loss and low-nonlinearity pure silica core fiber complying with ITU-T G.654.E, and started supplying it for terrestrial long-haul networks. The excellent practicality of PureAdvance, including reliable terrestrial cabling, low splice loss, and stable Raman amplification, have been demonstrated for actual deployment as terrestrial links. Transmission systems using PureAdvance exhibit higher transmission performance than those with SSMF or NZDSF, making PureAdvance ideal as a transmission medium to support long-haul, high-capacity terrestrial applications including telecom trunk lines, datacenter interconnection, and transmission lines between submarine landing stations and datacenters.
With the ever-increasing demand for reducing the environmental impact, there is a need for overhead transmission lines that can reduce transmission loss. We have been working to improve the conductivity of aluminum alloys for overhead transmission lines. This time, by improving the alloy composition and processing methods, we have developed a new thermal-resistant aluminum alloy wire with an allowable continuous operating temperature of 150°C and high conductivity of 61%IACS. In this paper, we introduce the development of the aluminum alloy wire and the characteristics of overhead transmission lines using the new wire.
With the expansion of the use of renewable energy, it is necessary to construct not only AC distribution systems that connect renewable energy power plants to the existing grid but also long-distance large-capacity DC transmission lines. The AC cable systems are prone to various problems such as AC harmonic resonance and current zero missing, which require designs based on power system simulation. The large-scale DC transmission lines are expected to play an important role as multi-terminal transmission systems in the future, and their electrical system design and submarine route design require advanced cable technology. This paper reports on our new cable system design methods for AC distribution lines and DC transmission lines that contribute to the increasing use of renewable energy.
The ITER project is being promoted as an international megaproject to scientifically and technically demonstrate the feasibility of fusion energy, which is one of the most promising candidates for achieving a decarbonized society. Among the components of ITER, tungsten (W) is used for a divertor, which is exposed to ultra-high temperatures above 2000°C. For stable operation of ITER, W is required to exhibit excellent thermal shock resistance under a high-temperature heating/cooling cycle. In this study, we have newly developed a W with an improved thermal shock resistance by suppressing the grain growth due to high temperature. Using the developed W, monoblocks were fabricated for small-scale mock-ups and plasma facing unit (PFU) prototypes, and their performance was evaluated by high heat flux test (HHFT) simulating a fusion reactor. HHFT results showed that no cracks occurred even under severe conditions. In particular, the evaluation results of the prototype greatly exceeded the requirements of ITER, and the developed W was certified as “unbreakable tungsten” for the first time in the world.
High-performance F-theta (Fθ) lenses are applied to CO2 laser drilling machines of printed wiring boards to drill micro-via holes with high precision, high speed, and high throughput. They are generally made of zinc selenide (ZnSe) or germanium (Ge), but Ge is more temperature sensitive and has higher absorption than ZnSe. Therefore, as laser power increases, deterioration in the stability and quality of laser drilling tends to occur. Taking advantage of our strength as a comprehensive optics manufacturer that produces a complete range of products from ZnSe materials to finished laser optics products, we have developed a new F-theta lens using ZnSe for all lens elements and a cover window with a diamond-like carbon (DLC) coating. Here, we provide the technical outline of the development
In steel machining, particularly in the automotive industry, various efforts are being made to reduce the environmental impact and to use resources efficiently. We released the AC8000P series for steel turning in 2016, which uses the new chemical vapor deposition (CVD) coating technology “Absotech Platinum,” and are continuously expanding the product lineup. Meanwhile, there is a strong need for cutting tools that demonstrate a long tool life and stable performance. To satisfy these demands, we have developed a new steel turning carbide grade, AC8020P, which shows excellent wear resistance and chipping resistance in high-efficiency machining. Together with the existing AC8000P series, the new AC8020P will reduce machining costs in a wide range of steel turning operations.
We have been developing the iDS coating system series with improved productivity and film performance since 2012 by reviewing the conventional coating systems from the basics. The iDS series has increased compatibility with a variety of applications by expanding the lineup of chamber sizes. This time, we have developed and launched iDS-720, which is suitable for mass production of tools and manufacturing of large punches and dies.
We have been focusing on carbon nanotubes (CNTs) as a material for next-generation electric wires that are lighter and more conductive than copper and aluminum wires. CNT single fiber has a greater conductivity than copper and the highest tensile strength of any known material. Aiming at the practical application of CNT electric wires, we have discovered the effectiveness of applying tensile stress to CNTs during the growing process from iron catalysts. In addition, at the University of Tsukuba, where a joint research was conducted, the growth of centimeter-class single fibers was observed in high-speed airflow, suggesting that stress applied during the growth contributes to the lengthening of CNTs. Using this principle as a basis for the growth method, we have created a metric-class CNT yarn that aggregates these long CNT single fibers. The new yarn has several times the strength of the conventional CNT yarn and exceeds the tensile strength of commercially available carbon fibers. This yarn will not only replace carbon fibers but also create new applications that have never been seen before.
Magnesium alloys have the lowest density of all practical metals. Our AZ91 magnesium alloy sheets are used for thin and light laptop computer bodies due to their superior strength and corrosion resistance in addition to their lightweight. In the electronics industry, 5G devices are being implemented to take advantage of IoT or AI, which can cause heat generation in electronic devices. One of the solutions to this is to improve the thermal conductivity and heat dissipation of the device bodies. In this paper, we introduce a new magnesium alloy sheet, SMJ140, having thermal conductivity in a range from 120 to 140 W/(m·K). These values are doubly higher than that of the AZ91 sheet. The heat dissipation of the SMJ140 is similar to that of a commercial aluminum alloy sheet A5052.
In 2030, Japan will enter a super-aging society where one in three people will be 65 years old or older. In a social environment, where all kinds of services are changing with the rapid digitization, elderly people with low IT (information technology) literacy are isolated from society. In addition, the aging of supporters who take care of the elderly in the community and the shortage of those supporters have become major social issues. In addition, the prolonged pandemic of COVID-19 has led to a new problem of the elderly becoming isolated due to the lack of face-to-face contact. In the field of welfare, where people support people, the need for IT-based non-contact monitoring systems is expected to grow further in the future. This paper introduces the joint research that Nissin Systems Co., Ltd. has conducted with the Kurobe City Council of Social Welfare in Toyama Prefecture since 2019, based on the company’s concept of “Anyone can easily connect with the community.” The authors present an ICT (Information and Communication Technology) terminal that was developed in the research project for the elderly at home and the support services using the terminal.
The properties of electric wires made of copper and aluminum are largely affected by the temperature and time of heat treatment. In order to optimize heat-treatment conditions, we have developed an in-situ measurement technique that uses synchrotron X-rays, which have high transparency and intensity. While this technique is expected to reduce measurement and analysis time, its application to actual operation has been limited due to the opportunities for measurement and the time required for data analysis. In this paper, we report new environmental control systems at our synchrotron beamline in SAGA-LS and a newly developed program for the automatic analysis of large amounts of data. We have confirmed that the in-situ measurement of copper and copper alloys is possible and the difference in softening behavior can be analyzed in a short time.
Conventionally, halogen lamps have been used for automotive headlamps and rear lamps. Recently, however, LED lamps have been increasingly used due to their long service life, low power consumption, and quickness to attain maximum brightness. Regarding the internal structure of in-vehicle LED lamps, an LED lamp and a driver module are built into the housing, as shown in Fig. 1. Automotive low-voltage electric wires are used for the wiring. Electric wires used in LED lamps must have anti-fogging characteristics to prevent fogging of the glass over long-term use. However, the electric wire covering causes fogging of the glass due to outgassing after a long period of use. Thus, the electric wire covering used for wiring in LED lamps must have low outgassing properties. This paper introduces our newly developed insulation material with low outgassing properties derived from our proprietary blending technology.
Electric vehicles (hereinafter “EVs”) and quick chargers have come into widespread use around the world toward achieving a decarbonized society. Sumitomo Electric Industries, Ltd. is supplying EV charge Cable with Connector “CHAdeMO conformity” for Quick Charger in the global market to connect EVs with quick chargers. SEVD-11 and SEVD-02, which are supplied by Sumitomo Electric, are shown in Photo 1, and their basic characteristics are shown in Table 1.
Since January 2020, we have seen the spread of the novel pneumonia caused by the novel coronavirus. Comparisons of the disease with the Spanish flu epidemic, which took place a century ago, has been on everybody’s lips. The 1918 influenza pandemic is said to have led to more than 40 million deaths, accounting for 2% of the then world population of two billion. Although it is known as the Spanish flu, it is said that the source of infection was U.S. soldiers entering World War I bringing the disease from the United States to Europe. In the first-ever world war, many people, including soldiers, moved and came into contact with other people on a global scale. Probably due to this, infectious diseases could spread very quickly. It is said that the death toll of World War I was 15 million in total, including both military personnel and civilians. Consequently, the number of victims of the Spanish flu was far greater than those of World War I. The world then faced truly difficult times.
In recent years, increased demand in the aircraft market has led to the need for higher production efficiency of aircraft parts. Heatresistant alloys and titanium alloys, widely employed for aircraft engines and structural members, are classified as difficult-tomachine materials and require cutting tools with high efficiency and long service life. In order to meet these user needs, Sumitomo Electric Industries, Ltd. has developed next-generation cemented carbide tools specialized in machining heat-resistant alloys and titanium alloys. For heat-resistant alloys, a new cemented carbide material with excellent high-temperature properties suppresses plastic deformation and wear even in high-speed, high-feed machining, enabling highly efficient machining. For titanium alloys, a newly developed film coating significantly reduces the reaction with titanium alloys, suppressing adhesion to the tool and extending the service life.
The cubic boron nitride (cBN) cutting tool “SUMIBORON” is mainly composed of cBN particles that have low activity with iron, and has high hardness and high thermal conductivity next to diamond, contributing to productivity improvement and cost reduction in the finishing of difficult-to-cut ferrous materials. In the past decade, the automotive industry has strongly driven the shift to hybrid electric vehicles and electric vehicles, which requires higher precision and higher efficiency in machining of sintered ferrous alloys and cutting tools with stable performance and longer tool life for cast iron. The authors have successfully developed a new grade “SUMIBORON BN7115” for finishing these materials. BN7115 employs a high-purity cBN particles and new binder consisting of Co-Al-Cr-WC to improve the bonding strength between cBN particles, thereby achieving good resistance to wear and breakage. BN7115 is expected to solve problems such as a degradation of the cuting surface of sintered ferrous alloys caused by the dropout of cBN particles and chipping of edges caused by thermal shock during cutting cast iron.
SUMIBORON BINDERLESS is a polycrystalline cubic boron nitride (CBN) that directly binds nanometer- or sub-micron-level cBN particles without binder materials (Binderless CBN: BL-CBN). BL-CBN is harder or has better thermal conductivity than conventional CBN. Therefore, it offers higher efficiency and longer tool life in the machining of difficult-to-cut materials, such as cobalt-chromium alloys, titanium alloys, nickel-based heat-resistant alloys, and hardened steel for use in the aircraft, mold, and medical industries.
The progress of digitalization increases the need for automated and unmanned cutting process. Sensor-equipped cutting tools are expected to be one of the measuring instruments that help visualize and monitor cutting operations because they are positioned closer to the cutting point than conventional measuring instruments, enabling more precise measurement. Sumitomo Electric Industries, Ltd. has promoted research and development on turning tools and milling tools that are equipped with sensors, wireless communication devices, and electric power sources. This paper presents feasibility studies on the monitoring of cutting operations with our sensor-equipped turning tool and milling tool.
Ceramic coatings adopted to cutting tools include chemical vapor deposition (CVD) coating and physical vapor deposition (PVD) coating. The CVD coating has excellent wear resistance and heat resistance, but is inferior in toughness to the PVD coating. By controlling the coating structure on the nanometer order using the CVD method, we have established a new CVD coating technology that ensures the toughness of PVD coatings while maintaining the wear resistance and heat resistance of conventional CVD coatings, and enabled its mass production. This paper reports on its unique structure, excellent physical properties, and outstanding cutting performance when applied to cutting tools.
In automobile-related industries, the use of aluminum alloy and other nonferrous metal parts has been increasing to reduce the weight of vehicles for improved fuel efficiency and to respond to the increasing production of hybrid vehicles, electric vehicles, and fuel cell vehicles. To increase the productivity in machining of these parts, cutting tools are required to be easy to handle and highly effective in chip control, for reducing machining time and no-machining time. Furthermore, there is also a growing demand for lighter cutting tools suitable for compact machining equipment to improve the productivity per unit area of machining equipment. To meet these demands, Sumitomo Electric Industries, Ltd. has developed a polycrystalline sintered diamond (PCD) cutter, ALNEX (ANX Series), for high-efficiency machining of aluminum alloys. This paper describes the features of the new cutter.
Nickel-based heat-resistant alloys, widely used for aircraft jet engines and power plant gas turbines, are difficult-to-cut materials causing short tool life in the grinding process. To meet the market needs for extended tool life and increased machining efficiency, we have developed an innovative electroplated cubic boron nitride (CBN) grinding wheel, CB Master. CB Master demonstrated 5 times longer tool life in grinding jet engine parts, and 1.5 times higher efficiency in processing gas turbine parts than conventional wheels.
The advancement of electric mobility as well as improvement in the efficiency of home appliance and industrial equipment have led to a need for higher performance motors. Axial gap motors (AGMs) are attracting attention as a motor that meets the need because of their low profile and high torque compared to radial gap motors. We have demonstrated the high torque and high efficiency of AGMs with soft magnetic powder composites (SMPCs) and started mass production of SMPCs for AGMs. In order to contribute to the further adoption of AGMs, we have developed a low-loss SMPC, pole-shoe teeth core, and thin-insulation-coated SMPC.
With the increasing performance of variable valve timing (VVT) systems, there is a growing demand for powder metallurgical parts with more complicated geometries. On the other hand, high productivity is also required in the manufacturing process to respond to the increasing demand for VVT parts. Accordingly, we have applied green machining, which achieves both high formability and productivity. This technology allows green compacts to be machined “before sintering,” which makes it possible to process parts about nine times faster than conventional post-sintering machining and thus enables volume production.
In an advanced information society where IoT and drones will widespread and in the near future where multitasking robots will be active due to the declining birthrate and aging population, there will be a greater need for stronger and lighter communication wires more than ever. The Special Steel Wire Division has developed thick copper covered (TCC) wire, which is a conductor composite material in which a high-strength steel wire is coated with a thick copper layer. TCC wire has higher strength than other copper alloy and composite material wires, and is particularly superior in flexibility. This paper reports on the characteristics of TCC wire.
SmART Strand is a prestressing steel strand equipped with an optical fiber to accurately measure the tension along the entire length of the prestressing steel cable. For prestressed concrete structures and ground anchors, it is important to ensure that the required tension of prestressing steel cable is provided and maintained. In order to directly evaluate the tension of prestressing cable during the installation and use, a new measuring method using SmART Strand has been developed. SmART Strand can be used for the maintenance of prestressed concrete structures and ground anchors, as well as their prestressing management.
We have developed a new aluminum material that has electrical conductivity and thermal conductivity close to those of pure aluminum, while maintaining strength even at high temperatures. As international regulations on carbon neutrality and CO2 emissions are being tightened at an accelerating pace, and emphasis is being placed on thermal management of electric devices and communication devices that contain high power semiconductors, aluminum materials are expected to be an alternative solution to copper-based materials for their light weight, high electrical conductivity, and high thermal conductivity. However, their application range is limited due to the decrease in strength at high temperatures above 150°C. Using powdered aluminum obtained by a quenching solidification method as a raw material, we have succeeded in developing a new aluminum material that maintains strength up to a high temperature of around 250°C, while also maintaining electrical conductivity and thermal conductivity close to those of pure aluminum. We are confident that this new material can meet the needs for lightweight conductive parts and heat dissipation products.
Synthetic diamonds have been widely used in industrial applications due to their high purity and low crystal defects compared to natural diamonds. It is also possible to endow specific electrical and magnetic properties by doping with different types of elements, and is expected to be applied in various fields such as sensing and measurement. We have succeeded in producing a diamond with the world's highest level of purity and lowest level of defects by using our unique high-pressure and hightemperature method. Furthermore, we have created a highly sensitive sensor with the nitrogen vacancy (NV-) center by electron beam processing and ion implantation in cooperation with Nissin Electric Co., Ltd. This paper introduces the high quality diamond synthesized for the NV sensor and its applicability.
Transportation management systems are one of the business support tools for logistics companies. Conventional systems require manual operation to change the route plan after the vehicle is dispatched, considering its current position and the time of visit to the customer. Therefore, we have developed a vehicle route planning engine and application programming interface (API) that enable real-time modification of the route plan, such as adding new tasks, even after the vehicle is dispatched. In addition, we have developed an automatic vehicle management system that enables users to check the past dispatch results and current task progress. This paper introduces the functions and performance of these systems.
For reducing traffic accidents and congestion, the need for infrastructure sensors is increasing worldwide. In order to cover a large area, multiple infrared sensors are deployed and work together to detect and track vehicles. We have developed a system and detection algorithm to integrate multiple infrared millimeter-wave radars. In this paper, we present the features of the system and the results of field tests.
A thermopile, which is a type of cooling-free infrared sensor composed of thermoelectric materials, and detects infrared rays without using electric power. For making a high-performance sensor, we developed a germanium-silicon (Si-Ge)-based thin-film thermoelectric material. The thermal conductivity of the Si-Ge thermoelectric material was reduced to 1 Wm-1K-1 due to the artificial nano-structure in the materials. In addition, its Seebeck coefficient was effectively increased by co-doping. This paper demonstrates that the thermopile constructed using the developed nanostructured Si-Ge material successfully detects infrared rays, and a gases detection system using the thermopile detects methane in the ambient air.
A large number of high-pressure fluid-filled (HPFF) and high-pressure gas-filled (HPGF) pipe-type cables had formerly been installed in U.S. power transmission lines since 1930s. As the pipe-type cables age, corrosion of the steel pipes and leakage of the dielectric fluid have become a problem. Using technology patented in the U.S. and Japan, Sumitomo Electric Industries, Ltd. designed, delivered, and installed its new high-voltage cross-linked polyethylene (XLPE) triplex cable and its accessories for the existing transmission lines.
We supply heaters for heating semiconductor wafers in the single-wafer film deposition processes. Semiconductor wafers are indispensable for 5th generation communications, artificial intelligence, automatic driving, and large-capacity data storage in data centers. The refinement of semiconductor circuits requires the formation of uniform films on wafers, and this demands uniform temperature distribution in the wafers. Conventionally, heaters have been divided and arranged in concentric zones, but this does not cover the subtle unevenness of circumferential temperature distribution caused by various factors in the device environment. To overcome this challenge, we have developed a multi-zone heater and a controller capable of high-accuracy control.
Recently, Communication traffic has been increasing rapidly with the development of cloud computing, video distribution, 5G support, and other IT services. In association with this, there has been an increase in demand for smalldiameter, high-fiber-density optical cables in order to overcome physical restrictions of space in ducts. In Europe, North America, and other regions, air-blown optical cables are widely used for FTTH since they make it possible to extend existing conduits (microducts) without additional roadwork, thereby enabling economical network construction. A small-diameter duct used for installing optical cables by blowing compressed air is called a microduct. With the recent increase in transmission capacity and the popularization of FTTH, the need is growing for densely installing a large number of optical fibers into microducts. Sumitomo Electric Industries, Ltd. has developed and launched a 432 or fewer count optical fiber cable suitable for air-blowing installation. The new optical fiber cable comprises an intermittent 12-fiber ribbon core made up of 200 μm optical fibers (“200 μm 12-fiber Freeform Ribbon”) that are thinner than conventional optical fibers with an outer diameter of 250 μm.
With the recent popularity of telework, as well as the development of remote medical care and cloud services, data communication volume is increasing rapidly. To cope with this situation, there is a need for the construction of high-speed, large-capacity, low-latency communication networks using optical fibers. At the same time, the companies responsible for network construction have high expectations for a drastic improvement in work efficiency to efficiently manage the increased construction work. In order to meet these expectations, Sumitomo Electric Industries, Ltd. thoroughly pursued the ultimate in workability for the previous fusion splicer, TYPE-201e, without changing its features: compactness and lightweight. As a result, the company has developed a new ultracompact optical fiber fusion splicer, TYPE-201+ .
The author received the Yahagi Memorial Award 2019 from the Technical Committee on Dielectrics and Electrical Insulation, thevInstitute of Electrical Engineering of Japan. In this paper, memories of the late Prof. Kichinosuke Yahagi and his teachings arevdescribed by a former student. The teachings of Prof. K. Yahagi can be summarized as “Seek the Truth.” The author pursued avnumber of truths according to said teachings in his research and development endeavors. The development of cross-linkedvpolyethylene insulated DC power cables rated for the world’s highest voltage was brought about as one of the results of thevteachings.
Optical fiber communication started to become practical use in 1970, when an optical fiber with a transmission loss of 20 dB/kmvand a laser diode continuously emitting at room temperature appeared. Sumitomo Electric Industries, Ltd. has enterprisinglyvdedicated the development and commercialization of optical fibers since the early days. Utilizing the vapor-phase axial depositionvmethod, which has spread worldwide as a preform manufacturing process, we have kept launching high-quality optical fibers andvcables such as ultra-low-loss silica core fibers and ultra-high-density optical cables. This way, we have continued to support thevexpansion of optical fiber networks as one of the indispensable social infrastructure. This paper looks at the evolution of opticalvfiber technology and our efforts in developing optical fibers and cables that would meet the need of the time.
Electric vehicles and hybrid electric vehicles are in widespread use and these vehicles are all equipped with DC/DC converters forvcharging lead-acid batteries from high-voltage storage batteries. To simplify the installation, DC/DC converters are required to bevsmall. This paper describes a DC/DC converter that has been downsized by 50% compared with conventional ones by increasingvthe switching frequency from 100 kHz to 500 kHz using GaN devices.
Magnetrons have long been used as transmitting devices for marine radar, however, gallium nitride high-electron-mobilityvtransistors (GaN HEMT) are increasingly adopted due to their long life, high performance, and compliance with radio laws andvregulations. This paper presents our internally-matched X-band GaN HEMT that feature the industry's highest output power of 300vW, targeting a variety of marine radars ranging from small-power radars for pleasure boats to high-power radar for largecommercialvvessels. We also report on a prototype compact solid-state amplifier that has been made to demonstrate thesevtransistors.
In recent years, gallium nitride high-electron-mobility transistor (GaN HEMT) amplifiers with high efficiency have been adopted due to the increasing demand for downsized and low-power-consumption base stations. In 5G networks, where further improvement in network capacity and data rates is required, the presence of GaN HEMTs is expected to grow further due to their advantages in broadening the bandwidth of amplifiers. This paper describes the characterization and analysis method for the current source of GaN HEMTs that we are working on to develop the GaN HEMT amplifiers for base stations. We newly adopted a large-signal lowfrequency measurement that enables evaluation under conditions close to the actual radio frequency operation, to explore design guidelines for GaN HEMTs. In addition, we analyzed the effect of gate voltage clipping in class-F and inverse class-F operation, which is known as a method for improving the efficiency of amplifiers by using a large-signal model to figure out the limiting factorvof efficiency.
A large capacity of the Internet is strongly demanded due to the increase of internet-connected devices and the diversification of internet-based services. To address these needs, we are in a new phase to upgrade the transmission speed of access optical networks from the current mainstream 10G class to 50G class. We have developed a new transimpedance amplifier (TIA) capable of receiving 25.78 Gbit/s burst signals to meet the demand for higher-speed transmission. Using the TIA and avalanche photodiode (APD), we have developed a 25.78 Gbit/s/λ burst-mode receiver, and confirmed its applicability to 50G-EPON optical transceivers for the first time in the world.
We have developed a wavelength division multiplexing transmission method to efficiently connect radio base stations and antennas with a small number of optical fibers. In the fifth generation (5G) radio access networks, there is demand for a technology that can economically transmit 25G Ethernet signals over up to 40 km by wavelength division multiplexing (WDM). This paper introduces the half-rate transmission method that enables 40 km WDM transmission by dividing 25.8 Gbit/s signals into two channels of 12.9 Gbit/s signals and transmitting them.
Silicon carbide (SiC) power devices are promising next-generation devices and their market is growing globally year by year. The quality of SiC epitaxial wafers is particularly important to secure the reliability of large-current power devices used for automotive applications. Basal plane dislocation (BPD) in the SiC epitaxial wafers causes stacking fault expansion, which leads to the fatal degradation of SiC bipolar devices. To suppress the stacking fault expansion, the introduction of highly nitrogen-doped layer called a “recombination-enhancing layer” has been proposed. In this study, we have established a method to evaluate BPD in the recombination-enhancing layer by investigating the receiving filter using photoluminescence imaging, and successfully obtained a 150 mm SiC epitaxial wafer with extremely low BPD density. We also confirmed that BPD and surface defects in the drift layer were simultaneously suppressed, demonstrating the new epitaxial wafer has stable characteristics for large chip devices.
To ensure the stable operation of utility-scale solar power plants over a long period, it is necessary to improve the inspection and maintenance levels, especially the inspection efficiency of the DC voltage parts, for which visual inspection has been conducted. Sumitomo Electric Industries, Ltd. has developed a system that detects abnormalities in solar panels by analyzing string data with AI. Data on detected abnormalities, including their types and urgency, are reported to the power plant manager via daily emails and used for efficient facility maintenance. Using the system, we also provide diagnostic services suggesting best inspection methods and countermeasures for the abnormalities.
With the expanding introduction of renewable energy sources and advances in semiconductor and energy storage technologies, direct current (DC) distribution systems that combine renewable energy sources and storage batteries have attracted attention as economical and environment-friendly next-generation power supply systems. These systems are also expected to help improve power system resilience and business continuity planning (BCP). This paper introduces the background of our study and the details of the DC distribution demonstration system built at the Nissin Academy Training Center.
We have developed a new diamond-like carbon film “HC-DLC," which is produced by vacuum arc deposition and contains hydrogen. With its appropriate hydrogen content, this film obtained extremely low attackability to soft metals without compensating its high wear resistance and seizure resistance in engine oil containing MoDTC. The film demonstrates excellent performance in protecting piston pins that repeatedly slide on soft metals. To meet market needs, the mass production of the film started in the fall of 2019, and now further application to the next-generation high-efficiency engines is under consideration.
Sumitomo Electric Industries, Ltd. has been engaged in the development of high-performance and long-length Bi2223 hightemperature superconducting wires. These wires and their applied products, such as current leads for magnetic resonance imaging, have been commercialized and well received by the market. This paper describes the recent development and commercialization of Bi2223 wires and typical products incorporating the wires, as well as wire joint technology and high-current conductor technology, which are indispensable for expanding the application of the wires.
For research and development in material science, it is important to understand the three-dimensional (3D) distributions of chemical species in samples. The effective utilization of 4D big data which contain a lot of information about the 3D distributions is a key factor. This paper demonstrates a new 4D data analysis technique called “two-step multivariate curve resolution (MCR)”. To obtain an intuitive expression of 4D data, we devised a process involving two iterations of MCR with digitization in between. The new technique was applied to the analysis of time-of-flight secondary ion mass spectrometry data derived from a thin-film sample to assist in the interpretation of complex three-dimensional local microstructures. Compared to conventional methods of data presentation, two-step MCR was found to greatly facilitate the clarification and understanding of the 4D analysis data.
In order to meet the demand for high dimensional accuracy in powder metallurgy products, we have been developing powder simulation techniques to support the design of the production process. Powder simulations provide a macroscopic interpretation of powder behavior by calculating the motion of individual particles that constitute the powder. In this paper, the powder simulation is applied to the milling process of raw powder and the powder feeding process of metal powder. Although the milling efficiency can be predicted from the collision energy of the balls in a ball mill, it is necessary to reproduce the motion of each ball with complicated collision process to predict the collision energy accurately. In this study, we have developed an analysis technique to predict the change of the collision energy when the milling conditions are changed, in order to improve the performance of the milling process. We have also developed an analytical technique to visualize the powder behavior in the powder feeding process to clarify the mechanism of the filling variation in the die.
"In recent years, there has been an increase in the demand for by-wire technologies for improved safety and convenience. Brake-by-wire and shift-by-wire technologies, which have been widely used, are essential for future selfdriving cars. The market is expected to expand for them in the future. However, as the by-wire-technology controls a device through electrical signals, a control failure occurs if the vehicle power source such as a lead-acid battery becomes out of order . Sumitomo Wiring Systems, Ltd. and AutoNetworks Technologies, Ltd. of the Sumitomo Electric Group have developed an x-by-wire backup battery designed for uninterrupted by-wire control even in the event of a vehicle power failure."
"Our copper wire manufacturing technologies, which originated from Sumitomo’s copper business, were subsequently applied to electrical wire and cable products. Based on these products, the Sumitomo Electric Group has continuously developed its new technologies and products. Electrical wire and cable manufacturing technologies are divided roughly into conductor technologies and covering material technologies required for insulating wires. Let us take a look at the history of diversification of Sumitomo Electric’s products along with the growth of these technologies."
As part of its overseas business, Sumitomo Electric Industries, Ltd. has been providing contact wires for the high-speed dedicated freight corridor that is being constructed in India. To enter the Indian contact wire market, it was necessary to satisfy the specifications required by the local customer, such as high conductivity and high tensile strength based on overseas standards. Taking advantage of our accumulated expertise in copper-tin alloys, we achieved the required properties by adjusting the tin and oxygen ratio in material casting and by improving the drawing process of contact wire. This paper introduces our technical development.
The air spring is an essential component for improving the comfort of railway vehicles and realizing safe high-speed driving. Due to the growing urban population and increased concern about environmental issues, railways are attracting attention because they have higher transportation efficiency than automobiles and aircraft and contribute to the reduction of CO2 emissions and energy consumption. As the railway network spreads all over the world, air springs with various characteristics are required depending on the route and environment. To respond to such market needs and make proposals in a speedy manner, we are developing innovative design methods based on computer simulation. This time, we have developed a simulation technology that accurately predicts the static and dynamic characteristics of air springs.
The electrification of vehicles has been advanced rapidly with the aim of reducing environmental impact. This paper summarizes the transition of motor design technology and its future development trends with a focus on driving motors for electric vehicles as a benchmark. We also report on the current status of our efforts towards the development of rectangular wires that contribute to the improvement of motor performance. In our efforts, we have worked to enhance the insulation performance of the film coating for magnet wires and reduce their size variation.
Magnet wire is an electrical wire coated with an insulation film. We analyze its constituent elements such as a conductor, insulation film, and the interface between them, in order to improve the quality and performance of the wire. It is increasingly important to develop novel and advanced analysis technologies and use them depending on the purposes of analysis. This paper reports on our unique technology and approach to the analysis of the aforementioned elements.
With the spread of mobile devices, market needs are increasing for the improved sound quality of small speakers. Self-bonding magnet wires used in the voice coils of small speakers are required to be durable against vibration and to be lightweight for enhanced responsiveness in a high-frequency range. Our copper-clad aluminum wire is resistant to fatigue fracture caused by vibration. The wire comes with various densities and conductivities by changing the composition ratio of the copper coat and aluminum core. This paper reports on the development of the wire that has increased flexibility in coil design and durability for the improved sound quality of small speakers.
The composite metal wire is composed of multiple metallic phases and has multiple functions at a relatively low cost. The Sumitomo Electric Group offers a variety of composite metal wire products that are made by cladding and plating. This paper introduces the technologies and application examples of our wires.
Celmet, the unique porous metal product of Sumitomo Electronic Toyama Co. Ltd., has high gas-diffusivity and high electric conductivity. Celmet is a good candidate for the cathode current collectors of solid oxide fuel cells (SOFCs) that require uniform gas-diffusivity and high electric conductivity. Thus far, we have examined the application of nickel (Ni) Celmet to the collectors, however, the desired output power density has not been obtained due to the decrease in electric conductivity caused by the oxidation of Ni at high temperature of the fuel cells. We have developed new nickel cobalt (NiCo) Celmet that forms conductive ceramics, keeping high electric conductivity at high temperature and highly oxidizing atmosphere. This paper introduces the physical properties of the NiCo Celmet and reports on the performance of an SOFC that uses the new Celmet for its cathodic current collector.
Heat shrinkable tubing is used for the insulation and mechanical protection of electric wires in fields such as electronics and aircrafts. Among such tubing, dual-wall heat-shrinkable tubing is used for the waterproofing of automotive wiring harnesses at the joints of electric wires. In recent years, with the aim of improving fuel efficiency and reducing vehicle weight for the reduction of CO2 emissions, aluminum wires have been attracting attention as the replacement of conventional copper wires. We have developed a new dual-wall heat-shrinkable tubing for the anti-corrosion protection of aluminum wires at their terminals.
Fluororesin, represented by polytetrafluoroethylene (PTFE), is an excellent polymer that has the lowest level of friction performance among solids and the highest level of heat resistance, chemical resistance, weather resistance, and electrical properties among resins. In contrast, it has poor wear resistance and hardly adheres to substrates when used as a composite material. Through electron beam irradiation under special conditions, we promoted the cross-linking reaction of fluororesin and developed a new material that features wear resistance improved nearly 1,000 times compared with the conventional material and good adhesion to substrates. This paper investigates the cross-linking state of the new material using solid-state nuclear magnetic resonance, and elucidates its adhesion state to substrates utilizing SPring-8 hard X-rays.
We have applied cross-linking technology to plastic materials through high-energy electron-beam irradiation to obtain gears with high durability. Sumitomo Electric Fine Polymer’s Teralink cross-linked gears, which use polyamide 66 as their base polymer, exhibit a three-fold improvement in durability in terms of the amount of tooth load that they can withstand compared to gears made of the same base polymer.
Porous polytetrafluoroethylene (PTFE) membranes were first developed by Sumitomo Electric Industries, Ltd. as “POREFLON.” Thanks to its high chemical and heat resistance, POREFLON has been used for microfiltration in various industrial applications. With advanced technological innovations, Sumitomo Electric has newly developed a nano-porous PTFE membrane “POREFLON NANO” and confirmed its high degassing and gas separation performance.
We have developed and marketed a new POREFLON membrane module unit for water treatment. It has a smaller footprint and is more energy saving than conventional products. In addition to the features of the conventional POREFLON hollow fiber membrane such as fouling resistance, high strength, and bending resistance, the module unit features the cassette type module structure, increased effective membrane length, enhanced packing density, and newly developed air diffusers that generate large air bubbles to prevent fouling. In a pilot test for municipal wastewater treatment jointly conducted with Japan Sewage Works Agency and others, we achieved a power consumption per unit of 0.4 kWh/m3 or lower, which was the target point for the popularization of membrane treatment. The module unit passed another several field trials and was currently commercialized. This report introduces the development process, product specifications, and case studies regarding the new membrane module unit.
Sumitomo Electric Industries, Ltd. has developed an Ethernet access switch for Carrier Ethernet that contributes to the reduction of operation expenditures. We have integrated functions of a fiber optic media converter and a layer-2 aggregator into one Ethernet access switch. This has enabled a power- and space-saving solution compared with conventional device sets. The switch features hitless firmware upgrades, zero touch provisioning, NETCONF, alarm notifications and line test capabilities. At the end of the paper, we report on the experimental results of Streaming Telemetry.
This paper reviews device design and performance of high-speed vertical cavity surface emitting laser (VCSEL) arrays for nextgeneration short-reach 400 Gbit/s applications in data centers using the advanced PAM-4 modulation format. The both 850 nm/900 nm PAM-4 VCSELs have been optimized to improve dynamic performance and suppress noise for PAM-4 transmission. The new VCSELs also show good uniformity of characteristics, which is advantageous for array products.
Demand for high-resolution displays and virtual reality applications is increasing and the use of these devices is spreading rapidly in the consumer electronics market. Cables attached to these devices are required to support high-speed and long-distance transmission, while maintaining their plug size. We have developed an active optical cable with a USB Type-C connecter (a smallsized multifunctional interface) and a plug of the same size as that of a conventional cable. This paper introduces the new cable, describing its design, transmission characteristics, and results in a reliability test.
In the machining industry, long tool life and high machining efficiency are required for cost reduction and productivity improvement, and sudden troubles need to be reduced for factory automation. Furthermore, machining facilities have been increasingly integrated into single facilities that can process various work materials. In such circumstances, we have developed a general-purpose grade “ACU2500” that achieves a stable and long tool life in the milling of a wide range of work materials including steel and cast iron. We have also developed special grades ”ACP2000 / ACP3000” and “ACK2000 / ACK3000” that offer high machining efficiency and long tool life in steel milling and cast iron milling, respectively. While covering a wide variety of work materials, these five grades demonstrate 1.5 times longer tool life and twice higher efficiency than conventional grades, enabling significant cost reduction and productivity improvement.
Cermet tools, characterized by low affinity with steel, realize high-quality finished surfaces in steel cutting and are commonly used for finishing. In the automobile, industrial machinery, and other manufacturing industries, high machining efficiency has become important year by year for lessening the environmental impact and machining costs. In increasingly severe machining conditions resulting from the pursuit of high efficiency, cermet tools are strongly required to offer long tool life and high-quality finished surfaces. Under such circumstances, we have developed and launched “T2500Z,” a new cermet grade that features a long tool life and excellent finished surface quality. The T2500Z has twice the tool life of our conventional steel-turning grades, thus making it possible to meet user needs for high efficiency.
Thermoelectric generation that directly converts waste heat into useful electric power has attracted considerable attention as one of the most efficient techniques leading to a low carbon, sustainable society. For automobile exhaust heat power generation, the figure of merit (ZT) of thermoelectric materials, which parameterizes the efficiency of energy conversion, needs to be more than 4, but at present it is considered to be extremely difficult to reach. We are conducting research and development to overcome this issue by modulating the electronic structure of materials, that is, with precise control of nanostructures. By controlling nanostructures, we have succeeded in lowering the thermal conductivity of conventional Si-Ge thermoelectric materials to 1/7 and improved their materials figure of merit. In this study, in order to improve the performance even further, we propose a unique technique called a co-doping method (modulating electronic structures with doped Au and controlling the Fermi level with doped B). With this method, we have achieved ZT = 1.38, which is the best result for the same materials of the same type.
A quantum cascade laser (QCL) is the most promising semiconductor laser for trace gas sensing in the mid-infrared region due to its excellent features such as a small chip size, high speed modulation, and a narrow linewidth. In practical gas-sensing, QCLs are required to achieve single-mode operation and wide-wavelength tuning without mode-hopping for high-sensitive and multiple gas detection. To obtain the wide tuning range of QCLs, increasing the operation temperature is effective. Therefore, we have developed a distributed feedback (DFB)-QCL that can operate at high temperature by introducing our original strain-compensated core structure and buried-hetero waveguide structure. As a result, we have successfully achieved single-mode operation without mode-hopping between -40ºC and 200ºC under a pulse condition, leading to a wide tuning range of 123 nm with only a singlewaveguide QCL. As a future challenge, we will develop a gas-sensing method using the above-mentioned DFB-QCLs as the light source.
In recent years in Japan, behind the widespread use of cloud computing, data center networks serving as a fundamental technology have been handling an increasing amount of data transmission, which also lead to a growing for increased ultra-high-fiber-count and higher-density cables. Sumitomo Electric Industries, Ltd. has successfully commercialized the world’s first cable containing 3456 or more fibers and shipped it to its many customers.
"With the recent expansion of cloud services, countries around the world are facing a pressing need for building data centers. Optical fiber cables for data center applications now comprise of thousands of core optical fibers. There is a noticeable tendency for these cables to be made even denser by increasing the number of core optical fiber cores, for example, from 1728 to 3456. As optical fiber cables become increasingly dense, data center construction companies have high expectation for a device that improves work efficiency through mass fusion splicing of ribbon fibers. To meet these users’ new expectations, Sumitomo Electric Industries, Ltd. has developed a new ribbon fiber splicer TYPE-72M12 that both saves optical fiber splicing/heating time and reduces workloads."
Along with the progress of global warming, the introduction of renewable energy sources such as solar and wind power has been promoted, and large-capacity energy storage batteries have become important as a measure to stabilize electric power systems. A redox flow battery (RFB) is one of such batteries. It is charged and discharged by redox reactions*1 of ions in an aqueous solution containing active materials*2. The RFB is suitable for large capacity storage and has excellent features such as long life and high safety. We began developing RFBs in 1985 and have delivered approximately 30 units. As a global trend, research and development have been actively promoted particularly in the United States, Europe, and China since around 2010, and recently, there have been many reports on new electrolytes using organic compounds. This paper introduces the development history of RFBs, the demonstration status of large capacity systems, and the recent development trends.
Recently, the demand for silicon photonics (SiPh) optical transceivers for data centers has been increasing rapidly. In order to address this situation, we have developed FlexBeamGuidE (FBGE) as an optical interconnection device indispensable for SiPh chips. The FBGE is an optical fiber array with a 90-degree bend, formed using state-of-the-art stress-free fiber bending technology. The developed FBGE is suitable for use in SiPh optical transceivers because of its compact nature with an overall height of less than 3.8 mm, low attenuation loss of less than 0.5 dB, and high reliability.
This paper describes a newly designed ultra-high-density (UHD) microduct optical cable to be installed into microducts with airblowing technique. The UHD microduct cable employs Freeform Ribbon, in which fibers meet and split out in turn in longitudinal and transverse directions, thus allowing high fiber density and mass fusion splicing. In order to enhance the blowing efficiency, we employed a thin and lightweight cable design and low friction jacket material. In addition, we have significantly increased fiber density owing to a bend-insensitive and thin optical fiber and Freeform Ribbon technology. We also evaluated the blowing performance in collaboration with Plumettaz S.A. to confirm the excellent blowing property of the developed cable.
There has been a strong demand for increasing data traffic resulting from the growth of advanced mobile terminals and the diversification of internet-based services. To address the needs, 100-Gbit/s optical transceivers have been used in optical communication systems. For further increase in data capacity, a new specification for 400-Gbit/s optical communications has been standardized, and optical transceivers applicable to it have been developed actively. We have developed a new compact receiver for 400-Gbit/s transmission based on the structure of our previous 100-Gbit/s receivers. This paper describes the design and typical characteristics of the new optical receiver.
Gallium nitride high electron mobility transistors (GaN HEMTs) are characterized by high power, high efficiency, and wideband operation. In recent years, they have gained market share for base station applications. GaN HEMTs are more advantageous for wideband applications than LDMOSs and, therefore, expected to contribute to the establishment of high-power multi-band base stations. This paper presents a packaged GaN HEMT device with internal matching circuits. A high-power wideband asymmetric Doherty amplifier using the devices are also described. The transistor has a pair of 180 W GaN dies. The internal matching circuit is designed with a high-dielectric substrate so that it can be mounted in a compact package while maintaining the wideband characteristics. The asymmetric Doherty amplifier is fabricated using three transistors to cover B1 and B3 LTE bands. It achieves an output power of 59.2 dB and drain efficiency of more than 50% at 8-dB power back-off in the 1.8-2.2 GHz range.
For the next-generation power systems, a mechanism called Virtual Power Plant (VPP) is expected to be deployed, where distributed energy resources are aggregated and remotely controlled by a resource server so that it operates like a virtual power plant. Sumitomo Electric Industries, Ltd. has developed what is called a resource aggregation server, s EMSA server, which plays a core role in this mechanism. Sumitomo Electric has been working to develop VPP systems and extend energy resources in order to enter a new electric power market that will be created after 2020. This paper presents the features of sEMSA server and its verified performance in pilot projects for VPP operation and photovoltaic power generation control.
Copper conductors cross-linked polyethylene insulated wires are widely used for overhead distribution lines in Japan. On the other hand, a trend can be seen in the shift from copper conductors to aluminum conductors because aluminum is light and moderately priced. For the replacement, however, the increased diameter of insulated wires is inevitable due to the difference of conductivity between aluminum and copper. This causes an increase in wind pressure on wires, occasionally requiring rebuilding supporting structures (for example poles). Under such a circumstance, we have developed a low wind-pressure aluminum insulated wire with an original grooved surface. This helps reduce the wind pressure at a wind velocity of both 28 m/s and 40 m/s. Featuring competent electrical performance and workability for connection and other wiring work, the wire has been applied to actual distribution lines.
The “System UPS” is an energy solution system that achieves both peak shaving and business continuity plan (as a countermeasure for instantaneous voltage drop and blackout). It combines battery energy storage systems with emergency generators on the consumer side. Aiming to present a solution that offers new customer value as part of our SPSS (Smart Power Supply System) business, we are conducting verification at Maebashi Factory of Nissin Electric Co., Ltd. We report on the development progress and demonstration results of the System UPS.
Exotic alloys, such as nickel alloys, cobalt alloys, and titanium alloys, are widely used for equipment and parts in the aircraft and auto industries due to their superior heat and corrosion resistance. There has been a growing demand for the machining tools for these alloys. When machined, exotic alloy work materials are likely to adhere to the edges of cutting tools, resulting in a sudden fracture of the tools. These tools have a significantly shorter life than those used for general steel. Thus, demand is high for cutting tools with stable performance and long tool life. The newly developed grades, AC5015S and AC5025S, are characterized by improved wear and fracture resistance with a state-of-the-art physical vapor deposition coating and special cemented carbide. These materials help reduce tool replacement frequency and tool consumption by extending tool life, thus contributing to the reduction of machining costs.
In recent years, the quality level required for diamond dies has risen along with an improvement in the precision of wire materials such as semiconductor bonding wires and medical wires. Requirements are increasing for wire characteristics, particularly wear resistance and properties to maintain roundness and wire surface roughness. In order to meet the needs, we have developed the BLPCD die using a nano-polycrystalline diamond (Sumidia binderless) developed by Sumitomo Electric Industries, Ltd. as its core material. This paper reports the performance evaluation results.
Extrusion tools made of refractory metals, such as molybdenum (Mo) and tungsten, are used in increasingly severe environments. Nevertheless, these tools are required to have superior mechanical properties, long life, and excellent reliability. We have developed a new Mo alloy “MSB” for hot extrusion dies used in plastic working, by using a dispersed Mo-base intermetallic compound. The MSB exhibited superior mechanical properties compared with conventional Mo alloys at temperatures below 1000°C. In addition, by adding a titanium alloy to the MSB, we have developed another alloy “T-MSB” that has high mechanical properties at high temperatures. In the hot extrusion of brass, dies made of these Mo alloys had 2.5 times longer tool life than conventional Mo dies.
In the development and production of compound semiconductor devices, atomic-scale structural analysis is required to evaluate their performance and characteristics. For the analysis, scanning transmission electron microscopy (STEM) is indispensable. However, it is necessary to control the sample thickness to around 100 nm using a focused ion beam (FIB) milling system, and the required number of samples could not be prepared quickly even by highly skilled engineers. In order to solve this problem, we have improved the processing capacity by automating the FIB milling process. Since a wide variety of devices are being developed and manufactured in our company, it is necessary to prepare various kinds of samples according to the analysis objectives of each device. Therefore, we identified the automation conditions for each sample, and by combining the established automation functions we constructed a system that can deal with a large number of samples expeditiously. The higher throughput enables us to repeat the device fabrication and evaluation in the shorter turnaround time, accelerating the development of devices and improvement of the quality.
With the recent tightening of fuel consumption/emission control regulations, Zero-Emission Vehicle regulations, and other environmental regulations, the use of electrified vehicles (electric vehicles, plug-in hybrid vehicles, hybrid electric vehicles) is expanding. A motorized vehicle is equipped with a battery pack for powering electric motors. In the battery pack, multiple battery modules are connected to each other to produce high-voltage, highcapacity power. In the battery module, the electrodes of multiple laminated battery cells are electrically connected in series or parallel by the bus bars of a battery wiring module. A control unit is connected to the battery modules via the wires of the battery wiring module to monitor the voltage of each battery cell .
The OPTHERMO fiber-optic distributed temperature sensing system is a product of Sumitomo Electric Industries, Ltd. and is one of the component technologies used in infrastructure monitoring and maintenance systems. There are currently two models in the OPTHERMO lineup: the FTR3000 (a short distance model at an accessible price) and the FTR3000X (a long-distance and high-performance model at a higher price). By limiting its functions, the FTR3000 has offered the most reasonable price in Japan among equivalent products. However, it is 10 years since FTR3000 was introduced to the market, and therefore it was time for the product to be updated with functional enhancements and other changes. We have now developed a successor model, the FTS3500, which offers better performance while still maintaining the lowest price in Japan.
Recently, automobile-related industries are required to protect the global environment by improving the fuel economy of vehicles. To meet the requirement, vehicle manufacturers are increasing the use of aluminum alloy and other nonferrous metal parts to reduce vehicle weight, in parallel with an increase in the production of hybrid vehicles, electric vehicles, and fuel cell vehicles. To increase the productivity of these nonferrous metal parts by improving machining efficiency, cutting tools are required to be easy to handle and feature highly effective chip evacuation, thereby reducing machining time and nonmachining time. In light of the situation, demand for lighter-weight cutting tools suitable for compact machining equipment is also increasing recently to improve the productivity per unit area of machining equipment. To meet such demand, Sumitomo Electric Industries, Ltd. has developed a polycrystalline sintered diamond (PCD) cutter, ALNEX (ANX series) , for high-efficiency aluminum alloy machining application.
A milling cutter is a cutting tool with a cutting edge on the end face or side face. Various kinds of parts are machined by revolving this cutter. Cutting tools equipped with indexable inserts are widely used today for face milling, shouldering, side milling, slot milling, contouring, ramping, helical milling, and various other types of cutting. On the other hand, in the field of machining, the accuracy and quality required of parts are becoming stricter year by year. Accordingly, cutting tools are required to provide increasingly enhanced performance in order to be able to cut the surfaces of parts to the required roughness and quality. To realize parts of reduced weight, the quantity of parts made by machining low-rigidity thin-walled workpieces and intricately shaped difficult-to-clamp materials is increasing. As a result, the demand for cutting tools with sharper edges is increasing.
The automotive industry has entered a major once-ina-century revolutionary era characterized by the connected, autonomous, shared/service, and electric (CASE) strategy. R&D efforts are strongly directed towards the next-generation motorized society. Meanwhile, global automobile sales are expected to continuously increase. At the same time, the market for environmentally friendly vehicles is forecast to grow substantially due to tighter environmental regulations to be enforced in many countries.
Automobiles and the environment surrounding them have been rapidly changing. The value that vehicles offer will change significantly as the concept of “connected” is added to the basic vehicle functions of “driving,” “turning,” and “stopping.” In short, vehicles will evolve from a simple means of transportation to a social terminal that provides mobility and various related services. Thus, not only individual users, but also the whole society may benefit from the added value. As vehicles are used as social terminals that will create new industries in the automobile society of the 2030s, new values may arise as management resources. Therefore, it is necessary to build key technologies adaptable to the newly created social needs in addition to the functional value of conventional vehicles. This paper outlines a next-generation in-vehicle electronic platform that is currently being developed as a new key technology for the era of connected cars by integrating our social infrastructure and in-vehicle technologies.
As the demand for the reduction of CO2 emissions from vehicles is ever increasing, lightweight wiring harnesses have been in high demand. Effective weight reduction can be expected by replacing conventional copper electric wires with aluminum electric wires. However, aluminum wires have several drawbacks such as low electrical conductivity and low tensile strength, as well as the thick oxide film on the surface and galvanic corrosion. To solve these problems, we have developed an aluminum alloy with improved electrical conductivity and tensile strength. We have also developed a unique terminal for a splice that maintains low contact resistance and sufficient wire retention force even on a thick oxide film. We have established an anti-corrosion technology that prevents galvanic corrosion by coating a new anti-corrosive onto the crimped joint of the terminal. This paper explains respective solutions in detail.
In-vehicle control software has become complex, and powertrains have been diversified due to the advancement of vehicle electrification pushed by tightening environmental regulations. Nevertheless, we are required to shorten our development time and propose driver-friendly vehicle systems. We have worked on the development of mechanical and electrical co-simulation techniques as well as simulation-based quantitative evaluation methods for the trade-off between power consumption and ride comfort. To strengthen our system design and solution proposal capabilities, we have also been developing a whole vehicle simulation technique. This paper introduces our virtual car that can be connected with the real driving environment, focusing on an electric vehicle charging system.
The introduction of high-speed automotive Ethernet to in-vehicle networks has been accelerated by the increase of communication volume resulting from the spread of advanced driving assist systems (ADAS) including autonomous driving. To ensure safety, in-vehicle network products require communication reliability even under severe conditions associated with extreme heat and noise, and therefore electromagnetic compatibility (EMC) performance is one of the important factors. However, conventional trial EMC countermeasures require a lot of efforts and development costs to ensure EMC performance. We have developed a simulation technology to efficiently verify the EMC performance of automotive Ethernet communication systems under various conditions by constructing the physical layer model of a communication system composed of connectors, wire harnesses, and electronic control units.
Sumitomo Electric Industries, Ltd. has developed and produced high-voltage wiring harnesses and connectors used for electric drivetrains, and these products have been used in many hybrid electric vehicles (HEVs). For the past quarter century, HEVs have been actively developed to prevent global warming caused by CO2 emissions. The development of electric vehicles (EVs) that require no internal combustion engines has also been accelerated. An electric drivetrain used in an EV mainly consists of a highvoltage battery, inverters, and motors. This paper introduces our products that have been developed for HEVs and are also applicable to EVs. These products include a pipe shielded wiring harness applied to the aluminum wire between the high-voltage battery and the inverters as well as a power cable and direct connector that connect the inverters to the motors.
The number of electrified vehicles, such as electric and hybrid electric vehicles, has been increasing rapidly due to concerns about the environment, energy savings, and rising oil prices. To promote the use of these vehicles, motorizing systems need to be reduced in size and weight while also ensuring running and acceleration performance comparable to that of gasoline vehicles. We have developed a compact and lightweight reactor, a key component for a boost converter used in the motorizing system. Using a new magnetic material and heat dissipation structure, we have succeeded in the size and weight reduction of the reactor by 10% while maintaining the same performance level as conventional reactors.
We have been producing wiring modules for high-voltage battery packs used in electrified vehicles. With the recent rapid expansion of the market, we have been promoting product development for electric vehicle (EV) applications. The number of battery cells used in an EV battery pack increases to extend the mileage, which in turn requires a reduction in the volume of battery wiring parts. For the widespread use of EVs, the safety of battery packs is another important factor. This report introduces our development on battery wiring modules for EVs.
In order to meet the CO2 emission target, the electrification of powertrains is accelerating in each country. The 48-V mild hybrid electric vehicle (HEV) can reduce CO2 emissions at lower costs than other systems, and therefore it is expected to become popular mainly in Europe. DC/DC converters installed in the mild HEV are required to supply high power with high reliability. We have developed a power control technology and achieved a high efficiency and high response compact converter. This paper introduces the features of the converter.
A surge current caused by a high-voltage inverter-drive motor system damages the insulation performance of magnet wires. Sumitomo Electric Industries, Ltd. has developed a novel magnet wire that has a uniform micro-closed cell structure in the insulation film. This paper discusses the excellent dielectric properties of the new magnet wire.
There are two categories for electric vehicles charging systems. One is normal charging (AC) and the other is quick charging (DC). In recent years, the application of the latter has been expanding due to an increase in the capacity of in-vehicle batteries. In 2011, we began supplying the SEVD series as a CHAdeMO-conformity 50 kW-class quick charger cable assembly and have since delivered 27,000 units mainly in Europe, U.S.A. and Japan. Our connectors have a high reputation for superior safety and operability. We responded quickly to the CHAdeMO specification ver. 1.2, which described high output, and began shipping SEVD-11 for over 100 kW-class high power charger connectors in the beginning of 2018.
Recently lithium-ion batteries have been widely used for electric vehicles. The states of batteries should be estimated accurately for their safe and effective use. We have developed a battery state estimation system that has a parameter estimation algorithm for a battery model. This paper describes the estimation results, including the state of charge (SOC) and state of health (SOH) for each battery cell, and presents the system that transmits these results to a server.
Tab-lead is an electrical lead wire used for a pouch lithium-ion battery (LIB) that features lightweight and high heat dissipation. Sumitomo Electric Industries, Ltd. has released the world’s first tab-lead in the late 1990s. Tab-leads have since been used for pouch LIBs that are applied to small electronic devices such as personal computers and cellular phones because of their high reliability. Since pouch LIBs are lightweight even if upsized for electric vehicle and hybrid electric vehicle applications, they have been in high demand. In light of this, we have developed a tab-lead for automorive use that offers high permissible current and long-term reliability.
As the electrification of automobiles advances, the efficiency of power devices used for electrical power control becomes increasingly important. Although silicon (Si) power devices have been commonly used, the adoption of silicon carbide (SiC) power devices, which are more power efficient than Si devices, have been accelerating. Against this backdrop, we have focused on the development of SiC metal-oxide-semiconductor field effect transistors (MOSFETs) with trench gates for high efficiency. Our trench MOSFETs can reduce the on-resistance with the V-groove structure and achieve a high breakdown voltage due to the electric field alleviating regions implanted around the trench bottom. Here we report on our V-groove trench MOSFETs (VMOSFETs) that have a rated voltage of 1200 V and current of 200 A as required for high current automotive applications. The VMOSFETs exhibit both a low specific on-resistance of 3.4 mΩ cm2 and a high breakdown voltage of 1660 V. In addition, the VMOSFETs also achieve high speed switching due to the electric field alleviating regions that reduce the parasitic capacitance.
Traffic accidents and congestion problems have been reduced by the efforts of public and private sectors. Sumitomo Electric Industries, Ltd., a leading supplier of intelligent transport systems, has contributed to the development and installation of wide area traffic management systems. For more safety, infrastructure-vehicle cooperative driving safety support systems using sensing and wireless communication technologies are expected to be one of the best solutions to traffic problems particularly near intersections. To meet these needs in the era of connected and automated vehicles, we have been researching and developing new technologies utilizing artificial intelligence and simulations. This paper reports on our previous and future efforts for advanced traffic management systems.
In light of the security incident of the Jeep Cherokee in 2015, where a vehicle was illegally controlled remotely using spoofing messages inserted via a public mobile network, security measures have become one of the most crucial issues in the realization of autonomous driving and connected cars. Taking security measures for each unknown cyberattack requires quick detection of attacks that happen throughout the life cycle of the vehicles. This paper introduces an intrusion detection system (IDS) to detect spoofing messages at the central gateway. Additionally, we report on the detection performance of the system using messages from an actual in-vehicle network.
Recently, quite a number of security attacks against Controller Area Network (CAN) have been reported. Many automotive companies are planning to adopt security countermeasures to strengthen security of their in-vehicle systems while saving the costs. This paper proposes a method to block unauthorized CAN-bus access using our enhanced CAN controller that prevents the transmission of messages from a malicious electronic control unit. We demonstrate the effectiveness of our device disabler on a CAN with Flexible Date rate buses.
In the urban area where the wireless roadside units of 700-MHz band intelligent transport systems (ITS) are densely installed, an operation method is required to install the units as many as possible by efficiently allocating limited radio resources without interference. This paper evaluates the radio resource allocation algorithm that utilizes simulation and proposes an installation and operation method devised based on the evaluation.
We are developing driving safety support systems to reduce traffic accidents. One function of this system is to provide information on the presence of pedestrians on a crosswalk to a vehicle turning right at an intersection and call attention to the driver. We have developed a 24-GHz band radar to detect pedestrians as a roadside sensor, and started shipping it in March 2018. The radar features robustness against changes in weather and sunshine conditions, high performance in pedestrian detection, and a wide detection area. This paper introduces the radar and shows the result of a field test.
In order to realize autonomous driving, millimeter-wave radar will become more and more important. Being used in the radar, printed circuit boards (PCBs) are required to have low-loss characteristics, because transmission loss is very high in the millimeterwave band. We have been developing low-loss PCBs made of fluororesin. We evaluated fluororesin substrates and confirmed their favorable transmission characteristics. We also prototyped an array antenna for automotive millimeter-wave radar using the substrate and successfully downsized the antenna surface area by approximately 40% compared with the conventional ones in the market.
Sumitomo Electric Industries, Ltd. has conducted a virtual power plant pilot program jointly with Nissan Motor Co., Ltd. and Kansai Electric Power Co., Inc. (KEPCO). In this project, 60 electric vehicles (EVs) parked at home and KEPCO were linked to the virtual power plant demonstration system, which simultaneously controls vehicle battery charge. This system is expected to enable the effective use of renewable energy, mitigating its output fluctuation. Through the adjustment of power supply and demand, we will add value to EVs.
The flexible flat cable has been used for electric wiring of electronic appliances. Along with the increase of electronic equipment installation in automobiles, the application of flexible flat cables has been increasing. Sumitomo Electric Industries, Ltd. has successfully produced a new flexible flat cable for automotive use featuring high heat resistance up to 150°C.
Sumitomo Electric Industries Ltd. started the development of the flexible wiring board “FUREKI” in the 1960s. Being light, thin, and highly flexible, FUREKI was well received by the market, and has been in high demand for the internal wiring of handheld units since the 1980s. Combining new materials and new technologies (such as connection technologies), Sumitomo Electric has added new products to the FUREKI series. This paper introduces our efforts for the application of FUREKI to automobiles.
Since the successful development of the world’s first AZ91 alloy sheet, which has high strength and superior corrosion resistance, we started the magnesium alloy business with the AZ91 alloy sheet used for the case body of mobile electronic devices. For application to transportation vehicle parts, however, the properties of AZ91 were not sufficient and we launched the development of new Mg alloys. Recently we have successfully developed a high-temperature creep resistant Mg alloy that can be applied to automobile powertrain components through a collaborative research with the University of Toyama. The new alloy has overcome the drawbacks of conventional creep resistant Mg alloys, such as the low castability and inferior recyclability. This paper introduces major properties of the developed alloys, which are necessary for practical applications in transportation vehicle parts.
Automakers have launched environment-friendly and fuel-efficient cars into the market. In such cars, decreased number of cylinders and expanded lock-up range are used to improve fuel efficiency. However, particularly in a vehicle with a 3-cylinder engine and continuously variable transmission, vehicle body vibration is aggravated by the influence of suspension resonance at the start of lock-up. To propose anti-vibration products that reduce the vibration, an analysis technique that covers drivelines and suspension systems is essential. Therefore, we have built a full vehicle analysis technique for evaluating a whole vehicle. With this technique, the reduction of vibration at the time of lock-up was examined using hydraulic strut mounts and the effects were confirmed in the actual vehicle evaluation. This full vehicle analysis technique is one of the fundamental technologies for our future product development.
For automotive fuel piping, we have been working on the reduction of fuel permeation to comply with regulations for hydrocarbon evaporation including low emission vehicle standards in the North America. Concurrently, in order to comply with the tightening CO2 emission control, we have also been working on the reduction of CO2 emissions by improving fuel efficiency through vehicle weight reduction. For this purpose, we have promoted the replacement of rubber hoses used for filler neck piping with those made a low fuel permeation material, and the metal filler pipe with a resin pipe. The replacement to the resin filler pipe involved the development of modules that consist of filler pipes and hoses. This paper describes these development efforts.
The automotive sector is currently undergoing a major transformation. This structural change is called “CASE” (connected, autonomous, shared, electric), and the electrification and digitization of vehicles are advancing rapidly. Under these circumstances, we have developed a magnetic induction foaming (MIF) technique for improving the thermal conductivity of sound absorbing polyurethane foam through magnetic field orientation, and succeeded in mass production of soundproofing products capable of achieving both thermal and noise countermeasures for in-vehicle electronics products. Recently, there has been an increasing need for heat dissipation and noise reduction for large products such as electric vehicle drive motors, in addition to in-vehicle small products. This time, focusing on the heat transfer structure of MIF, the heat dissipation property was improved by 2.5 times (up to 100 times of common urethane). Applying this method, this paper finds the possibility of MIF as a soundproofing cooling device that further enhances the air-cooling performance in addition to the soundproofing effect by covering the motor case.
Steel cords are widely used as reinforcing material for automobile tires. The adhesion of steel cord to rubber and long-term durability are increasingly critical factors not only in terms of fuel efficiency improvement but also the technological advancement of automobiles such as electric vehicles and automated driving. Focusing on the humidity heat resistance as an indicator of longterm durability, we have developed a ternary alloy plating with cobalt (Co) added as the third element in the brass plating of ordinary steel cord, and established its mass production technology ahead of the world. In this development, we also clarified the plating-rubber adhesion and its deterioration mechanism, enabling quantitative and quick evaluation of the effect of adhesion performance improvement. This innovative plating technology has substantially increased the durability of tires compared to conventional ones, being keenly anticipated by customers.
Active efforts have been made to create environmentally friendly products in the automobile market. Under this circumstance, parts that make up an automobile need to maintain their functions in harsh environments, requiring even higher durability than ever before. To meet this challenge, we have developed a diamond-like carbon (DLC) film that has an excellent rolling fatigue resistance for bearing parts. We also started the mass production of the DLC film coating for bearing parts by overcoming production technology challenges, and achieved both mass productivity and cost efficiency.
There has been growing demand for cloud servers due to the widespread use of IoT and smart devices. This has increased the demand for higher signal processing speed, namely, signal transmission speed. We already mass-produce metal cables for 40 Gbps differential transmission. We have developed a metal cable for 100 Gbps differential transmission designed for the next-generation communication protocol.
Exotic alloys such as Ni-based alloys, cobalt (Co)-based alloys, and titanium (Ti) alloys are often used for equipment and parts used in the aircraft and auto industries due to their superior heat resistance and corrosion resistance. There has been growing demand for tools for machining these alloys.
We have developed a microfracture strength evaluation technique that uses a spherical indenter made from nano-polycrystalline diamond. The technique enables us to evaluate the fracture strength characteristics in the micro regions of diamond materials with a high accuracy, which has been difficult in the past. Through evaluation tests on various types of single crystal diamonds using the technique, it was revealed that the fracture strength of natural diamond greatly differs depending on the location in each crystal, while that of synthetic diamond is uniform with small deviations. We also confirmed that the microfracture strength of nanopolycrystalline diamond is increased through grain refinement.
Vehicle electrification has been proactively promoted because of environmental restrictions. At the same time, new functions, such as autonomous driving and V2X communication, have made vehicle systems more complex. As the development costs have risen following these trends, system development using simulation has come into widespread use to improve cost efficiency. We have been developing simulation techniques to identify the effects of improvements in our product performance in regard to power consumption. This paper introduces a simulation technique to verify the trade-off between power consumption and ride comfort.
In a visual inspection setting, quantitative and qualitative judgment is needed. To automate this particular judgment process, an algorithm that resembles human recognition ability is required. Sense Learning is our algorithm that mimics the human recognition ability using the images of non-defective products. With an autoencoder, a deep-learning-based network, the inspection AI progressively learns to reconstruct the images of non-defective products, thereby acknowledging the ideal characteristics of products. When the image of a defective product is input, the inspection AI fails to reconstruct the defective part because it has never learned the form. Based on the difference between the input image and the reconstructed image, Sense Learning detects the defective part and measures the degree of its severity.
Level 3 or higher autonomous vehicles, which themselves control all aspects of driving, require lane-specific traffic information for safe and smooth driving. While this information is expected to be generated using probe data sent from vehicles, there are still problems such as the insufficient positioning accuracy of probe data for identifying the driving lane and the low penetration rate of probe vehicles. To overcome these problems, we have developed a system for generating lane-specific traffic information. The system uses images sent from on-vehicle front view cameras, which are in widespread use today, to identify the driving lane and the propagation model of traffic congestion to supplement the probe data.
For further automation and efficiency improvement of production, industrial control systems have been increasingly connected to other information systems to exchange data. Under this circumstance, establishing security measures for control systems against malware (such as Stuxnet*1) is an urgent issue. Therefore, security design has been taken into consideration at the beginning of the system development. In collaboration with the National Institute of Advanced Industrial Science and Technology (AIST), we have been applying security design guidelines for automobiles to control systems, aiming to improve the efficiency of design procedures without depending on personal knowledge or experience. Focusing on the risk-assessment phase in security design consisting of multiple phases, this paper proposes a quantification method optimized for the risk assessment of control devices and systems by utilizing an existing vulnerability assessment system. We report on the security design results using the method, providing a case study on a control system equipped with a data logger as the key element.
Physical contact (PC) optical connectors are commonly used for their favorable connection characteristics. However, PC connectors have some drawbacks such as the necessity of careful end face cleaning and an increasing mating force as the number of fibers increases. To overcome these drawbacks, we have developed a new multi-fiber connector that has an air-gap between its end faces. Eliminating the need for PC connection, this connector offers good optical characteristics and high reliability. This paper reports on the optical characteristics and reliability test result of the new connector.
With the growth of cloud services that require high-speed communication, CFP4 and QSFP28 optical transceivers have been commonly used for 100 Gbit/s transmission. Along with an increase in the market need for higher-speed transmission beyond 100 Gbit/s, the Institute of Electrical and Electronics Engineers (IEEE) published 400GBASE-FR8/LR8 as the next-generation communication standards, and the CFP Multi-Source Agreement (MSA) defined the CFP8 form factor of an optical transceiver to support 400 Gbit/s interfaces. Against this backdrop, we have developed a new optical receiver module for 400GBASE-FR8/LR8 CFP8. Using the conventional design for 100 Gbit/s, the module has an integrated 8-ch optical de-multiplexer. This paper describes the module structure, optical characteristics, and sensitivity in 26.56 Gbaud PAM4 signal transmission.
The demand for high-speed data communication systems has been increasing to accommodate huge data communication traffic resulting from the growth of smartphone and cloud computing services via data centers. This trend has generated a strong demand for high-speed optical transceivers. To transmit electric signals without distortion, transmission lines are designed with a due consideration of characteristic impedance. Nevertheless, electric signals tend to be distorted by unexpected factors on actual circuit boards. These factors often consist of signal integrity, power integrity, and electro-magnetic interference/electro-magnetic susceptibility, which are correlative to each other. For these problems, electromagnetic field analysis plays an extremely important role. This paper describes typical contributing factors, as well as problem examples and their solutions extracted by electromagnetic field analysis.
We have developed a 40-W microwave integrated circuit (MIC) equipped with gallium nitride (GaN) high electron mobility transistors (HEMTs) that is functional in the L-band and S-band for satellite and rocket launch control applications. The MIC has a 10-W GaN HEMT in the front stage and a 40-W GaN HEMT in the post stage. It achieves an output of over 45 W, gain of over 30 dB, and power added efficiency (PAE) of 45% in the range of 1.0-1.7 GHz, while it shows an output of over 47 W, gain of over 30 dB, and PAE of 50% in the range of 2.0-2.7 GHz. The GaN HEMTs met all the reliability and lifetime requirements in a space qualification test. When used in a solid state power amplifier, the MIC will contribute to a reduction in the size and weight of satellites.
As a solution to the rapidly increasing optical traffic, 100 Gbit/s transmission systems using the digital coherent optical communication technology has been adopted in high-speed and large-capacity optical transmission. Optical transceivers are required to be operable in the long wavelength band (L-band) in addition to the conventional band (C-band). Based on the design of C-band receivers, we have developed compact optical receivers for the L-band operation. This paper presents the design and typical characteristics of the new optical receivers.
Power devices have been essential to significantly advance efficient electric power use mainly for a future electric network society that will use versatile energy sources such as renewable energy resources and electric vehicles. SiC power devices are expected to be a key for power conversion systems to cut back electric power loss. To achieve large chip dies used in high current ratings, the wafer size of SiC substrates has increased, requiring precisely controlled fabrication processes. The epitaxial layer used for the drift region in a device structure strongly influences the device performance, entailing to the requirement of epitaxial defects reduction as well as the precise control of doping concentration and thickness for stable chip production. We have successfully demonstrated an extensive defect-free epitaxial layer with an excellent doping concentration and thickness uniformity on a 150 mm diameter 4H-SiC substrate.
Due to the development and wide-spread use of high-voltage direct current (HVDC) transmission and its related equipment, the evaluation of the dielectric properties of insulation materials under HVDC has become important. While the evaluation of electric properties is generally carried out using different methods appropriate for their specific purposes, the authors have found a relatively simple technique that can simultaneously evaluate multiple dielectric properties of a material, such as permittivity, space charge behavior, and electrical conductivity, using the direct current integrated charge method. This paper describes the principle of the method and measurement results of low- and high-density polyethylene and polystyrene.
With an increase in the use of renewable energy, the problem of power system constraints in which electricity transmission is limited has become significant. One major factor of this is the restricted capacity of transmission lines. While the enhancement of the transmission line capacity is necessary to solve this problem, it requires a large amount of capital and time. Therefore, it is important to utilize existing systems to their maximum potential. For the purpose of increasing power transmission capacity of existing systems, we have been developing a real-time monitoring system for the temperature and electric current value of power transmission lines. This paper reports on the present status of our ongoing developments.
Due to technological innovation utilizing information technology (the fourth industrial revolution), major changes are taking place at manufacturing sites. Internet of Things (IoT) technology is expected to improve production capacity and efficiency through the collection and analysis of a large amount of data by networking many sensors and devices. In the automobile industry, the development of common platforms and modules has been progressing, requiring parts manufacturers to cope with demands for cost reduction in super-mass production and quality risk management to prevent mega recall. To adapt to the age of megaplatforms, we have built an innovative sintered part production line making full use of IoT technology. Based on the Sumitomo Electric Group’s manufacturing concept, Sumitomo Electric Industries Production System (SEIPS), the new production line features: (1) zoned quality control by automated inspections, (2) quality assurance in units of products using 2D codes, (3) reduction of lead time and no intermediate stock by “one-by-one production / synchronized production” through compacting, sintering, sizing, to machining, and (4) IT-based production-management and monitoring systems.
Sumitomo Electric System Solutions Co., Ltd. Develops and sells AgentNavi, a navigation software development kit for smartphones. AgentNavi offers route guidance to the destination together with information about traffic congestion and regulations.
Information and communication services as well as the technologies that underpin these services have been developing rapidly. We have observed such developments as a user and a supplier. This paper aims to study the trends in the information and communication market based on relevant data to understand them correctly.
If wireless communication is utilized to collect data in a production site, manufacturing processes can be modified more flexibly without building a new network. However, it is not easy to achieve stable wireless communication in a factory because signal strength changes frequently due to various factors such as the rearrangement of equipment and the movement of machinery and workers. Therefore, we have developed a wireless repeater and controller that automatically manage communication quality. This development will enable full wireless networks for quick and reliable data collection.
The development of autonomous driving has increased expectations for advanced ITS technology. To prevent traffic accidents at intersections in Japan, for example, roadside radio units transmit information about oncoming vehicles detected by roadside sensors to vehicles waiting to turn right on the opposing side. This paper describes the prototype of a 76-GHz band radar applicable as a roadside sensor. The radar adopts a multiple-frequency-stepped CPC (complementary phase coded) modulation method characterized by long-range detection without resolution degradation. The performance of this radar was verified in a field experiment.
We have been producing pure-silica core fibers that enable low-loss transmission since as early as 1980s, contributing to the development of submarine optical cable networks through continuous reduction in transmission loss and nonlinearity of fiber. We have succeeded in further reducing the density fluctuation of a pure-silica core and developed an optical fiber with a transmission loss of 0.14 dB/km.
Communication systems based on conventional single-mode optical fiber transmission technologies may face a “capacity crunch” in the near future. To address this, Sumitomo Electric Industries, Ltd. has been conducting the R&D on various types of the multicore fibers (MCFs) for the space-division multiplexed (SDM) transmission. Since the very beginning of the SDM R&D, we have continuously contributed both to revealing the behavior and characteristics of the optical properties—such as inter-core crosstalk— of MCFs, and to proposing various MCFs for practical applications. This paper reviews our MCF R&D history.
The need for optical interconnection has been increasing at data centers (DCs) to process information for cloud computing and mobile internet services. To accommodate the need, multi-mode fiber systems will be replaced with single-mode fiber (SMF) systems. We have developed multi-fiber connectors (such as multi-fiber push-on and dust-proof connectors) as SMF optical connection solution based on high-precision molding technologies. This paper outlines our latest multi-fiber connectors for DC applications.
We have developed a chipset consisting of a transmitter device, a receiver device, and a power amplifier by using our 3-D Wafer Level Chip Size Package technology that allows miniaturization and cost saving. Mounting the chipset to a printed circuit board, we have developed a radio frequency module for 76-GHz band infrastructure radars. The module is as small as 20 × 34.5 mm2, in compliance with ARIB standard, and meets performance requirements for radar applications.
Infrared detectors with Type-II superlattices are attracting increasing attention due to their theoretically higher performance and lower environment impact than HgCdTe detectors. While quite a number of reports have been made on sensor development, only a few of them have discussed a long wavelength region over 14 μm, which is required for hyper-spectral imaging. Using a Type-II InAs/GaInSb superlattice, we have developed an infrared imaging sensor (640 × 512, VGA format) that functions in the wavelength range of up to 15 μm. At a temperature of 77 K and a bias voltage of -20 mV, the sensor obtained a dark current density of 3.7 × 10-3 A/cm2. The noise equivalent differential temperature (NEdT) of 0.29 K was achieved under an experimental condition using F/4 optics, a bias voltage of 0 mV, integration time of 200 μs, and temperature of 95 K. We succeeded in taking thermal images of a person.
This paper describes a newly designed ultra-high-fiber-count (UHFC) optical fiber cable for data center applications. The UHFC cable employs Freeform Ribbon, in which fibers meet and split out in turns in a longitudinal and transverse direction, thus allowing high fiber density and mass fusion splicing. Having a non-preferential bend axis, the cable can easily be installed in spaceconstrained areas. We combined the Freeform Ribbon technology with a new cable design to significantly increase fiber density compared to conventional underground cables while retaining their advantageous features such as easy handling, identification, and mass fusion splicing.
Sumitomo Electric Industries, Ltd. released the TYPE-3 fixed V-groove optical fiber fusion splicer for multi-mode fibers in 1980. Over the years, optical fiber fusion splicing technology has been making steady progress with the advancement of optical fiber production technology and the development of new jointing methods. This paper looks back at the history of splicing technology and highlights the technology that marked a crucial turning point in the progress. We also discuss our perspectives on how the technology can make further headway in the future.
Global data traffic has been steadily increasing with the spread of the Internet. High-density and high-efficiency cabling between server racks and devices has become more and more important for data centers. We have developed multifiber push-on (MPO) cassettes (PrecisionFlex) and a polarity conversion LC connector (FlexULC). This paper suggests a plug-and-play solution that eliminates the need for fusion splicing by using these new products in combination with round cords and trunk cables that use our MPO connectors (SumiMPO) for improved handling in the field.
A traditional PON (passive optical network) consists of an OLT (optical line terminal) installed in a cable television headend and ONUs (optical network units) at subscriber premises (Fiber-to-the-Premise, FTTP) or a distribution point serving multiple subscribers (Fiber-to-the-Distribution-Point, FTTdp). This paper describes a new class of products Sumitomo Electric Industries, Ltd. is introducing to assist North American MSOs (multiple system operators) to address fundamental requirements for their access networks such as distance, subscribers served per port, trunk fiber conservation, uniform operations support systems, and the cost of space, power, and cooling of equipment.
Gallium nitride (GaN) high electron mobility transistors (HEMTs) have been widely used for high-power and high-frequency applications, such as cellular base stations, owing to their superior material properties. This paper describes the features and characteristics of the world’s first commercialized GaN HEMTs. Specifically, it introduces our 400-W GaN HEMT Doherty amplifier for cellular base stations and 20-W broad band GaN HEMT for fixed wireless communications. For satellite communications and weather radars, we have also developed a high-power and high-reliability GaN HEMT. These GaN HEMTs contribute to the creation of small-form-factor, light-weight, and power-efficient transmitters for wireless communication.
Optical transceivers for high-speed transmission at more than 100Gbit/s have been downsized and implemented at increasingly high density. We have developed a new compact optical transmitter that consists of a low-coupling-loss optical multiplexer and four distributed feedback lasers with integrated electro-absorption modulators. This transmitter can be installed into QSFP28 to enable transmission at 100 Gbit/s up to 40 km and also used for 200 and 400 Gbit/s systems. This paper presents the design and performance of the transmitter.
In response to market expectations for 200 Gbit/s and 400 Gbit/s optical devices, we have developed a new compact receiver with four avalanche photodiodes and an integrated optical de-multiplexer for 40 km operating distance applications. This receiver is based on the structure of our previous 40 Gbit/s and 100 Gbit/s receivers and employs newly developed avalanche photodiodes for high responsibility. This paper presents the design and performance of the receiver, including its receiver sensitivity in 53 Gbit/s PAM4 (Pulse amplitude modulation 4) signal transmission.
Thunderbolt 3 is a high-speed and high-capacity input/output standard that enables bi-directional 40 Gbps transmission using a reversible USB Type-C connector. Based on Intel Corporation's technical specifications, Sumitomo Electric Industries, Ltd. has developed Thunderbolt 3 cables by combining its flexible and durable cables and high-speed transmission technologies to be the world’s first approved vendor of Thunderbolt 3 cables. This paper presents an overview of Thunderbolt 3 cables using Sumitomo Electric’s coaxial cables.
Heat shrinkable tubing with a meltable inner layer (dual-wall heat-shrinkable tubing) protects joints and connections in wiring harness connection with high adhesion, and has been widely used in electronics products and aircrafts. The application of the tubing has been extended to automotive wiring harnesses due to its easy handling and waterproof performance, and tubing that can be applied to complicated harness configuration is in high demand. To meet this demand, we have developed a new dual-wall heat-shrinkable tubing that shrinks at a low temperature and stays long. We optimized the shrink behavior and mechanical properties of the outer layer by controlling resin blending, and the flow and adhesion of the inner layer by applying the molecular design method and polymer alloy technology.
High-efficiency power semiconductors are becoming increasingly important for an energy-saving society. While metal-oxidesemiconductor field effect transistors (MOSFETs) are basically made of silicon (Si), silicon carbide (SiC) MOSFETs have been finding commercial applications due to advantages such as high efficiency owing to their material properties. We have been developing SiC V-groove trench MOSFETs (VMOSFETs), which achieve high efficiency through the combination of SiC material properties and optimized trench structures. By introducing an electric field concentration layer into VMOSFETs, we have succeeded in suppressing a gate insulation film breakdown at the trench bottom and improved the breakdown voltage. Moreover, we have realized fast switching VMOSFETs with a reduced switching loss of up to 70% by optimizing the structures and reducing feedback capacitance.
Thermoelectric generators, with which one can directly convert waste heat to useful electric power, have attracted considerable attention as one of the most efficient techniques leading to a low carbon and sustainable society. The figure of merit (ZT) of constituent thermoelectric materials is generally used as a measure for the efficiency of energy conversion in thermoelectric generators. The value has never reached a large magnitude exceeding 2, despite that ZT ≥ 4 is strongly required for automobile exhaust heat utilization systems. This large gap between the required values and obtained values let us believe that thermoelectric generators are not usable in practical applications. We need new, innovative techniques leading to a breakthrough for developing high-performance thermoelectric materials. In this study, we have developed an amorphous bulk material as a precursor of nanostructured thermoelectric semiconductors.
Sumitomo Electric lndustries, Ltd. installed a concentrator photovoltaic (CPV) power generation system in a high solar irradiation area in Morocco and evaluated its power output performance in comparison with a crystalline silicon photovoltaic (Si-PV) system. Based on the positive result, a megawatt-class CPV power plant was built in Ouarzazate, Morocco and is now operating for demonstration purposes. The CPV system is superior to the Si-PV system in energy generation per module area and effective rated power. The performance ratio of the plant has remained almost the same throughout the year, confirming its stable operation.
Axial gap motors have been attracting attention as demand increases for thinner motors with a higher output. However, radial motors using laminated steel sheets remain dominant in the market, and the use of axial gap motors is still limited due to the difficulty in producing three-dimensional magnetic cores with laminated steel sheets. We have built an axial gap motor using soft magnetic powder cores that feature magnetic isotropy and high design flexibility. The motor offers high torque and cost efficiency compared with a conventional radial motor of the same size.
To lessen the environmental burden, lead-free, difficult-to-cut materials are increasingly used and high-efficiency dry turning is becoming popular in the automotive industry. Under these circumstances, cutting tools need to have long tool life and offer stable performance. To satisfy these demands, we have developed the new coated-carbide grades AC8015P, AC8025P, and AC8035P for steel turning. This paper describes the features and cutting performance of these products.
We have developed a closed system for growing tomato seedlings using LEDs as the main light source. Although closed production systems reduce the risk of pest infection without using pesticides, tomato seedlings grown under artificial light for a long time are subject to physiological disorders. Our production system suppresses this problem and grows uniformly large seedlings, thereby shortening the cultivation period between seeding and harvesting. This paper describes how the system suppresses physiological disorders, while controlling air flow for uniform growth. (This research was conducted in collaboration with Chiba University.)
High-efficiency and high-frequency GaN-HEMTs (gallium-nitride high-electron-mobility transistors) for satellites and mobile phone base stations need to assure long-term reliability. The life time of these products is estimated based on the temperature of the channel layer (Tch), with a channel length of approximately 0.2 μm, located under the gate electrode. However, the current measurement method using an infrared microscope with a spatial resolution of 4 μm is insufficient to obtain the Tch precisely. We have developed a high-accuracy estimation method that uses μ-Raman spectroscopy with a spatial resolution of 0.8 μm, and achieved an accuracy of ± 5 degrees C by the optimization of sample structures for μ-Raman spectroscopy and careful calibration. It was confirmed that the life time of our existing products estimated by this method is 20 times longer than that estimated by the infrared microscope measurement on the same Tch.
Using strong synchrotron x-rays, advanced characterization can be performed for chemical-bonding states, atomic structures, and chemical reactions. We have constructed beamlines of our own called “Sumitomo Electric Beamline” in the SAGA Light Source to develop new materials and devices as well as improve existing products with advanced characterization. In our two beamlines using hard and soft x-ray, absorption spectroscopy, diffraction measurement, small-angle scattering, and photoelectron spectroscopy are performed. We began the construction of the beamlines in February 2015 and started operation in November 2016.
Regulations on chemical substances are being strengthened yearly in each country, and chemical substances contained in products such as electrical and electronic equipment are subject to regulation. In order to comply with such regulations, communicating information of chemical substances contained in products in the supply chain is necessary. For communicating information, international standards are set for electrical and electronic equipment, and construction of a mechanism for communication of information by industry groups, etc. Furthermore, in order to communicate accurate information, it is essential to manage chemical substances at each stage of design and development, purchasing and manufacturing, etc.
Connected vehicles that can wirelessly interact with the environment will become popular as they support safe and comfortable driving and offer improved functionality, security, and services to passengers. We have been evaluating and testing in-vehicle devices and infrastructure equipment in a realistic environment utilizing a testbed for concept proposals. This paper describes the features of the testbed and its application to the performance comparison of intelligent transport system (ITS) radio communications and the evaluation of vehicle-to-infrastructure cooperative systems.
Reduction in the transmission loss and nonlinearity of optical fibers used for submarine cables is important for meeting the evergrowing demand for telecommunication traffic. Pure silica core fiber (PSCF) has substantial advantages of low transmission loss and low nonlinearity because no dopant is added in its core. We have developed a PSCF having the highest transmission performance among commercialized optical fibers. The fiber, Z-PLUS Fiber 150 (Z+150), has been realized by improving our previous Z-PLUS Fiber 130 ULL (Z+130) in terms of both the glass quality and the mechanical performance of the protective coating. As a result, the transmission loss reduced form 0.154 dB/km to 0.152 dB/km, and the effective core area enlarged from 130 μm2 to 150 μm2. We have further confirmed an excellent manufacturability of Z+150 by the trial mass production of about 4,000 km fibers.
Sumitomo Electric Industries, Ltd. has developed a 125-μm-cladding coupled four-core optical fiber achieving the lowest spatial mode dispersion (SMD) and attenuation among optical fibers for space-division multiplexed transmission. The standard 125-μm-diameter cladding offers high mechanical reliability equivalent to that of field-proven standard fibers. The low SMD reduces the computational complexity of multiple-input-multiple-output (MIMO) digital signal processing. The low transmission loss comparable to that of conventional ultra-low-loss fibers contributes to the increase of the transmission capacity without sacrificing the per-core capacity. Furthermore, the transmission characteristics of this coupled multi-core fiber (MFCF) were experimentally confirmed to outperform those of an equivalent single-mode fiber (SMF). The present results demonstrate that the coupled MCF is suitable for ultra-long-haul transmission systems.
Digital coherent optical communication technology using multi-level modulation formats has been adopted in long haul systems as a crucial solution to the rapidly increasing optical traffic. This technology is expected to further expand to metro systems, where smaller optical transceivers are required. We have developed compact optical receivers that can be installed in the CFP2-ACO optical transceivers, complying with the OIF implementation agreement for Micro-ICR. The new optical receivers have achieved a high responsivity in a small package of 12.0 × 22.7 × 4.5 mm due to an InP-based PIC that consists of waveguide PDs and a 90 degree hybrid. They also include a VOA and signal monitor PD. The digital coherent transmission was verified by the successful demodulation of 128 Gbit/s DP-QPSK modulation and 224 Gbit/s DP-16QAM. This paper presents the design and typical characteristics of the compact optical receivers.
We have been developing communication equipment based on passive optical network (PON) technology to promote the widespread use of fiber-to-the-home (FTTH) broadband services domestically and globally. To accommodate the data traffic that has been increasing due to high-quality video distribution, we have developed a 10 Gigabit Ethernet PON (10G-EPON) optical line terminal (OLT) that supports nearly ten times higher line-speed transmission than the current Gigabit Ethernet PON (1G-EPON). This paper presents the 10G-EPON OLT that supports upcoming features of broadband video services, such as 4K and 8K resolutions, using existing optical distribution networks and optical network units (ONU) for 1G-EPON. It also reports on the lower size and power consumption of the 10G-EPON OLT, which will reduce operational expenditures.
We have developed a high-efficiency L-band 200-W GaN HEMT for space applications. Incorporating two 100-W dies, the GaN HEMT achieves a PAE of 71% and DE of 74.6% at 1.58 GHz in CW operation, demonstrating world-class efficiency in this product range. In a space qualification test conducted under high temperature and RF overdrive conditions, this GaN HEMT showed excellent performance, satisfying all the reliability and lifetime requirements for space applications. This paper describes the feasibility of an SSPA using the GaN HEMT, which will contribute to a reduction in the size and weight of satellites.
Metal oxide semiconductors are expected to be used for the thin film transistor (TFT) of large high-definition flat panel displays (FPDs) and In-Ga-Zn-O (IGZO), in particular, is already being mass-produced. For high-definition 8K FPDs, we have developed a new metal oxide semiconductor with a high electron mobility. Semiconductors used as a film in a TFT are made of oxide ceramics. We sintered the new metal oxide ceramic, In-W-Zn-O, as the base material of the new metal oxide semiconductor film and studied the properties of a TFT that used the new metal oxide semiconductor. The electron mobility of In-W-Zn-O was three times higher than that of IGZO and the stability of a TFT with In-W-Zn-O was superior to that of one with IGZO. In-W-Zn-O sintered material showed a high density and a low electrical resistivity, indicating that it is suitable as a sputtering target. This development will lead to the realization of 8K FPDs.
Automotive components have increasingly complex designs and thin walls for weight reduction, and accordingly, high-strength, difficult-to-cut materials are used. Meanwhile, high-speed and high-efficiency machining is also required to reduce lead time. Under these circumstances, cutting tools need to have long tool life and stable performance. To satisfy these demands, the authors have developed the new coated carbide grades AC4010K and 4015K for cast iron turning. This paper describes their features and cutting performance.
In recent years, variable valve timing (VVT) systems have been increasingly used for vehicle engines. The most common VVT is hydraulic systems because they require fewer parts and production costs are lower. However, the rising concern about the environment and demand for improved fuel efficiency have made VVT systems more complicated. We have developed a green machining technique that enables the one-chuck processing of a large number of complicated holes and lateral grooves and established a simple machining line for smart production. For quality assurance, compacts can be traced by 2D codes applied after in-line green machining.
The authors have developed a novel method for the fabrication of uniform epitaxial graphene on SiC substrates. Graphene was grown on the C-face 6H-SiC substrates with a sputtered SiC film by annealing at high temperatures. Observation using Raman mapping and low-energy electron micron microscopy revealed that 95% of this graphene consisted of two layers on the fractional area in a 75×75 μm square. This uniformity is quite high compared to that of graphene grown with the conventional method without sputtered SiC films, indicating the new method is more likely to be suitable for the fabrication of high frequency wireless devices.
To achieve a high facet reflectivity needed for the threshold current reduction (Ith) of a quantum cascade laser (QCL), we have developed an InP-based 7-μm Fabry-Perot (FP) QCL integrated with a distributed Bragg reflector (DBR). The DBR consists of semiconductor walls and air gaps which are alternately arranged by periodically etching the epitaxial layers of the air gap regions. The incorporation of a pair of 3λ/4 DBRs increased the facet reflectivity up to 66%, which was more than twice as high as that of a cleaved facet, and reduced Ith by 11%. This DBR-integrated FP-QCL succeeded in oscillation at up to 100°C in pulse operation and at up to 15°C in continuous wave operation, which is the first report on the operation of InP-based DBR-integrated QCLs. It also achieved sufficient output for sensing (up to dozens of mW). The DBR is expected to be used as a low-loss reflector suitable for front facet of QCLs.
Sumitomo Riko Company Limited has developed the smart rubber (SR) active mattress “Taiatsu Bunsan” for preventing bedsores. Consisting of stretchable SR sensors and double-decked air cells, this mattress automatically disperses the weight of bed-ridden patients to prevent ulcers. We are aiming to provide this product to clinics in order to improve the quality of life (QOL) of the patients and support their independence. This product will also lessen burden on caregivers by reducing the frequency of postural changes. We believe the Taiatsu Bunsan helps both patients and caregivers.
For the quantitative characterization of copper corrosion products, the author has developed a new voltammetric method that uses a strongly alkaline solution (6 M KOH + 1 M LiOH) as the supporting electrolyte. Using this method, he investigated the growth mechanism of copper oxides (i.e., Cu2O and CuO). When copper was heated with no adherent ions supplied, both Cu2O and CuO formed and grew. However, they showed different growth mechanisms when pre-immersed in salt solutions, and heated under high humidity. Cu2O grew selectively when copper was pre-immersed in LiCl and LiBr solutions, most likely due to Li+ ions permeating into the Cu2O layer and continuing proportionation (Cu + CuO → Cu2O). On the contrary, CuO grew at the early stage of heating when copper was pre-immersed in a KOH solution presumably because of the high OH– concentration in the water layer deposited on the copper surface.
Confronted with global warming and other environmental issues that have become tangible as a result of rapidly growing energy demand, mainly in developing countries, expectations are raising for stable and safe supply of environmentally friendly electric power and other energy sources. Under such circumstances, the environment surrounding electric power and energy is changing dynamically. In particular, expansion of power generation/transmission/distribution networks is being promoted on a global basis, use of renewable energy is increasing, and enhancement of the reliability of electric power systems is required in response to an increase in renewable energy consumption.
Amid the global changes in the fields of environment and energy, Sumitomo Electric Industries, Ltd. has started new business for energy systems and services. This paper explains the paradigm shifts that the energy field has been going through, and introduces the Company’s efforts in response to the shifts, including its organizational changes as well as the development of new products and technology such as vanadium redox flow batteries and concentrative photovoltaics.
Sumitomo Electric Industries, Ltd. has developed and commercialized a high-strength DI-BSCCO Type HT-NX wire. This wire is reinforced with Ni alloy tapes and undergoes residual axial compression after lamination. The wire has a critical tensile stress of 400 MPa at 77K. The new wire structure successfully reduced the splice resistance without sacrificing the mechanical properties. This wire is highly useful for nuclear magnetic resonance and other high field magnetic applications.
High expectations have been placed on rechargeable batteries as a key technology to power system reliability associated with introduction of an increasing volume of renewable energy, as well as efficient power supply and successful business continuity planning. We have developed a redox flow battery system that is safe with a long service life. A demonstration proved its applicability to multiple requirements from electric power companies and other businesses. This paper describes the system, demonstration results, and our effort to reduce the price.
Electric vehicles can be charged by either AC normal charge or DC quick charge. For the latter, a CHAdeMO DC quick charger was developed in Japan and has been widely used in Japan, Europe, and the US. We developed a DC charger connector that meets the CHAdeMO specifications, and have since supplied over 15,000 units of it and other connectors including those for vehicle to home applications. Our connectors have a good reputation for their operability and safety.
Large-scale batteries play an important role in the effective use of renewable energy like wind and solar power. Among various battery technologies, redox flow batteries (RFBs) offer high-speed response, independent design of power and energy, high safety, and thus have attracted more attention than ever. All-vanadium RFBs are the most mature technology and have been used in practical applications. As the prices of renewable energy power generation continue to decline, cost reduction of the battery system has become the major issue. In order to reduce the cost, many efforts have been made to develop a low cost electrolyte. We focused on a low cost manganese material, and developed a Ti (IV) and Mn (II) mixed aqueous electrolyte, and applied it to a Ti-Mn RFB. This paper briefly introduces development of electrolyte research and the characteristics of the Ti-Mn electrolyte.
While an increasing number of megawatt solar power plants have been constructed, some of them have already been facing problems with degradation in power output due to initial failures, aging solar panels, or external factors. We have developed a string monitoring unit that uses the power line communication (PLC) technology. These units monitor individual strings of hundreds of thousands of solar panels in real time without the need for wiring additional cables. We installed the units at a megawatt solar power plant, and successfully detected irregularities in power generation by analyzing data collected from the units.
The deterioration of overhead transmission lines in Japan has been continuing and transmission failures caused by corroded aluminum conductor steel reinforced (ACSR) conductors have increased year by year. From the viewpoints of securing reliable power supply and prolonging the life of ACSR conductors, Sumitomo Electric Industries, Ltd. has developed a high-corrosionresistance ACSR conductor jointly with the Kansai Electric Power Co., Inc. (KEPCO). The conductor is highly resistant to sea salt because of the high corrosion resistance offered by aluminum-manganese alloy clad steel wires used in the steel core part. The corrosion resistance of the conductor is about 1.6-2 times higher than that of the conventional ACSR/AC conductor. Using conventional materials for the aluminum wires, this product offers high economic efficiency with a minimal cost increase. Since 2012, the conductor has been installed into many transmission lines in KEPCO’s area and other regions in Japan.
Floating offshore wind power generation has attracted increasing attention because of the deep water levels around Japan. We have developed a dynamic cable system that stably transmits electric power from floating offshore wind turbines to a substation on land, and tested it in a demonstration project led by the Japanese Ministry of the Environment. During the demonstration, no problems occurred with the cable system, and a subsequent investigation found no remarkable deterioration. These results confirmed that the cable system withstands mechanical stress caused by the large excursion of hybrid spar-type floaters. We have also developed a method to analyze the behavior of the cable in the sea to optimize the cable installation design and ensure longterm reliability.
The cross-linked polyethylene (XLPE) cable has been used for DC transmission lines. We have been developing the DC XLPE cable for a few decades, and proved its quality and reliability through the research and development process. In 2012, we delivered the cable to Electric Power Development Co., Ltd. for its 250-kV DC transmission project, making it the world's highest voltage DC XLPE cable at that time and the world's first one to be applied to a line commutated converter system. Following the project, we successfully completed a pre-qualification test for a 400-kV DC XLPE cable. Currently, we are working two new projects: the 250-kV transmission project of Hokkaido Electric Power Co., Inc. and the 400-kV transmission project of NEMO Link Ltd. Our DC XLPE cable has an allowable continuous conductor temperature of 90 degrees Celsius, which is equivalent to the conventional AC XLPE cable, and withstands polarity reversal of voltage. This cable will meet the various needs of DC transmission that are expected to increase in the future.
Amid the changes in electrical power supply in Japan, Nissin Electric Co, Ltd. has been developing the Smart Power Supply Systems (SPSS) as a solution that integrates various distributed energy resources for power saving and stable power supply. The core system of SPSS, ENERGYMATE-Factory, enables the optimized control of energy provided by the combination of an electrical substation, one of the company’s major products, and various distributed energy resources such as solar power generators, cogeneration systems, and grid energy storages. This paper describes the ENERGYMATE-Factory and its features, and introduces a practical-scale demonstration conducted at the Maebashi plant.
It has been three years since the Feed-in Tariff (FIT) for renewable energy was introduced in Japan. While a reasonable number of solar power systems have started operation in Japan, functional improvement and cost reduction are still required for overseas solar power plants. We have provided 100-660 kW solar inverters for domestic use, contributing to the installation of megawattclass solar power generators. Drawing on the expertise, we have developed a new solar inverter to meet the needs of overseas customers.
When distributed power sources, such as renewable energy sources, are interconnected to electric power grids, anti-islanding protection devices are necessary. In 2001, we developed an islanding detector using the interharmonics current injection method, and since then it has been widely used. This paper introduces the principle, fault ride through (FRT) capability, and applications of the detector.
The Great East Japan Earthquake and subsequent electricity crisis, introduction of feed-in tariff (FIT) scheme, and the electricity system reform caused huge changes in the Japanese power system. These changes include the acceleration of installing renewable energy equipment, the enhancement of interconnections among regional power electric utilities, and the increase of the new power suppliers resulting from the full liberalization of retail power sales. This paper introduces Nissin Electric’s activities to solve power quality problems caused by the above-mentioned changes, from a viewpoint of the power system analysis.
Celmet is a material that has a high porosity and a large surface area. Sumitomo Electric Toyama Co., Ltd. has offered nickel and nickel-chromium alloy Celmets. There has been a demand for aluminum porous meatal due to advantages such as the light weight, thermal conductivity, and high voltage resistance. Therefore, we worked on the development of Aluminum-Celmet and succeeded in its production. This paper presents the physical properties, machine properties, and electric characteristics of the Aluminum-Celmet. We also report on the application of Alminum-Celmet to a lithium ion battery.
The recent growing awareness of the environment and interest in resource saving have raised the importance of metal recycling. As an electric wire maker that handles a large quantity of copper, we strive to promote copper recycling proactively and have developed a copper recycling technique using electrochemical processes for small-scale operations. We made the process as eco-friendly as possible and succeeded in continuously recycling electric wire scrap into high-purity copper.
Overvoltage, resulting from the application of a high frequency voltage, and its subsequent steep surge on an inverter-fed motor can significantly damage insulated systems due to partial discharge. Therefore, magnet wire with a high tolerance for surges and low dielectric permittivity is needed. This paper describes our new magnet wire coated with a porous insulator for enhanced surge resistance.
The advancement of hybrid electric vehicle/electric vehicle technology has led to an increase in the size of high-voltage cables used as power cables, and accordingly their flexibility is strongly required for easy handling. Our flexibility simulation revealed that the elastic modulus of an insulator contributes to the cable flexibility more than the structure of a conductor. We found that polyolefin polymers are ideal insulation base-resins because the softness of polyolefin can be controlled by the ratio of the crystal region and amorphous region, which changes with the amount of co-monomers. Using an anti-oxidant agent, flame retardant, and polymer cross-linking, we have developed a new flexible insulation material that meets JASO/ISO standard. Going forward, we will strengthen our product lineup of flexible cables.
In 2016, it was 100 years since Sumitomo Electric Industries, Ltd. first produced its enameled wire. The magnet wire, coated with an insulation film, has been used in various products including electrical components, household appliances, and electrical conductors, and supported the industry. This paper outlines the history of magnet wire from development to commercialization over the century and introduces our major products. We also discuss the direction of future wire development.
Air springs are part of a soft damping suspension system that provides both softness and damping characteristics by utilizing the compressibility and flow resistance of air. They were first used on railways about 60 years ago. The subsequent and continuous advancement of air spring technology is a result of the incorporation of air springs into Shinkansen trains and the acceleration of R&D activities in overcoming various challenges associated with increasing train speeds. To reduce the environmental impact of high-speed trains, the weight of each car was reduced dramatically. In particular, adoption of bolster-less bogies reduced car weight. Together with such technological innovations, the functions of air springs also changed remarkably. To make the Shinkansen competitive with aircraft by increasing both speed and ride quality, various new functional units were developed. Such units include the horizontally nonlinear air suspension system and the car-body tilting system with built-in air springs that enables trains to travel at higher speeds on curved tracks. A project aimed at further increasing train speed has been launched for several train lines. We will continue our R&D efforts to develop air springs that will enable trains to run safely at speeds exceeding 320 km/h while providing a truly comfortable ride.
Car manufacturers and suppliers are offering new systems, such as 48 V power supply or automated driving systems, for 2020 and beyond. Since these systems are closely related to automotive power systems, their deployment makes changes to the power architecture. To analyze requirements for power components, Sumitomo Electric Industries, Ltd. has been developing in-vehicle simulation technology that helps to investigate the relationship between vehicles and their components in performance. This paper introduces the technology to analyze the effect of power components on fuel economy, based on our mechanical and electricalco-simulation.
The weight of wiring harnesses has been increasing with the growing number of systems used in vehicles in recent years. For the purpose of reducing their weight, aluminum instead of the conventional copper has been getting popular as a wire conductor. Conventional Al alloys, however, cannot be used for small gauge wires (0.35 mm2 and 0.5 mm2) or in the engine compartments due to their insufficient conductor strength. For this reason, we have developed a stronger Al alloy that has a conductor strength equivalent to or stronger than that of copper, and successfully manufactured a high-strength Al alloy wire for the first time in the industry. Applying it the 0.35 mm2 wire used in engine compartment, we started its mass production in April 2015. The target properties of this alloy were a tensile strength of 220 MPa and conductivity of 50%IACS. Based on the age-precipitated 6000 series Al alloy, additive elements and their content were specified. The aging conditions were determined by examining the precipitation status of Mg2Si intermetallic compounds. With this approach, we achieved a tensile strength of 250 MPa and conductivity of 52%IACS, both of which exceed the targets.
Recent advancements in automotive electronic control systems have led to an increase in the numbers of electronic control units and circuits, and accordingly the number of the necessary connectors and terminals has risen. Meanwhile, multiway connectors require high insertion force, which makes the assembly operation difficult. Therefore, demand has grown for terminal plating that lowers the insertion force. We have developed a tin (Sn) alloy plating technique to replace the widely-used Sn plating. The Sn alloy plating restrains abrasive wear during connector matching and successfully reduces the insertion force.
We provide advanced broadband technologies and passive optical network (PON) equipment to the market. Recently, we have developed a repeater for 10 Gigabit-Ethernet PON (10G-EPON) systems. Installed between an optical line terminal (OLT) and optical network units (ONUs), the repeater significantly expands the data transmission distance from the conventional 20 km to 60 km. Wavelength division multiplexing (WDM) technology enables its connection to the OLT using an optical fiber and 8 channel support. This paper describes the performance of the repeater and the key technology in relaying upstream burst signals.
E-band wireless communication systems are expected to be used for fiber extension in the fixed network in order to support internet data transmission increased by the introduction of 3G/4G, LTE (Long Term Evolution), and other mobile backhaul services. The E-band communication system works in the 71-76 GHz and 81-86 GHz bands, enabling high data rate transmission of 10 Gbit/s or more. This system requires power amplifiers of an output power of 0.5 W (27 dBm) or higher to transmit high-order modulation signals over a long distance. This report introduces an E-band 1 W (30 dBm) class amplifier MMIC (monolithic microwave integrated circuit) incorporating a stabilization design and GaAs PHEMT (pseudomorphic-high-electron-mobilitytransistor) technology.
High output power gallium nitride (GaN) high electron mobility transistors (HEMTs) have been developed for S-band and X-band radar applications. The fully internally matched S-band GaN HEMT exhibits a minimum output power of 600 W, a minimum power gain of 12.8 dB, and a drain efficiency (DE) of 60% at 2.7–2.9 GHz for radar applications such as an air traffic control radar. The fully internally matched X-band GaN HEMT exhibits a minimum output power of 200 W, a minimum power gain of 9 dB, and a power-added efficiency (PAE) of 38% at 8.5–9.8 GHz for radar applications such as a marine radar and weather radar. The output power of these GaN HEMTs is the highest in the market, contributing to reduction in the size, weight and power consumption of radar transmitters.
Thermoelectric generators, with which one can directly convert waste heat to useful electric power, have attracted considerable attention as one of the most efficient techniques leading to a low carbon, sustainable society. The figure of merit ZT of constituent thermoelectric materials is generally used as a measure for the efficiency of energy conversion in TE generators, and its value has not reached a large magnitude exceeding 2 for the last half century, despite that ZT ≥ 4 is strongly required for automobile exhaust heat utilization system. This large gap between the required values and obtained ones strongly let us believe that a thermoelectric generator is not usable in practical applications. We need to employ new, innovative techniques leading to a breakthrough for developing high-performance thermoelectric materials. In this study, we tried to control nano-structured particles in amorphous thermoelectric materials so as to drastically improve the thermoelectric properties by means of molecular beam epitaxy for obtaining high performance thermoelectric materials.
Copper alloys are widely used in the automotive, electronics, and various other sectors. Among these alloys, beryllium-copper alloys need to be replaced with other materials due to concerns over their effects on human health and the environment. However, they have excellent properties that have slowed the replacement efforts. From this view point, Sumitomo (SEI) Steel Wire Corporation has developed a new steel wire by covering the surfaces of the steel core with a thick layer of copper. This wire provides the strength and yield resistance of steel wire and the conductivity of copper. Moreover, by using different percentages of steel core and copper, the material’s properties can be designed with ease. In fact, evaluations have revealed that the wire has mechanical properties comparable to or better than those of beryllium-copper alloys. This paper presents the results of mechanical property tests conducted on the wire.
In recent years, automotive components have become smaller and lighter due to the trend of energy saving and fuel efficiency. Accordingly, a wider variety of materials, including those difficult to cut, have been used for these components. Sumitomo Electric Hardmetal Corporation has developed the new coated carbide grade “AC1030U” by applying the new physical vapor deposition (PVD) coating technology “Absotech Bronze” and the new chip breaker “FYS type” that has excellent chip control and high wear resistance in fine finishing. AC1030U with high cutting edge quality and high wear resistance is a general grade used for precision turning. The new grade and chip breaker can satisfy the demand for cost reduction in precision machining for various materials such as alloy steels, carbon steels, stainless steels, heat-resistance steels, and pure iron.
New Sandponics (NSP) is a unique cultivation device that uses sand as the primary medium, and additionally employs a floor irrigation method in the early Sandponics. Using only 10% of the sand medium volume used in the early Sandponics, NSP reduces the device weight and maintenance costs. The floor irrigation method has enabled us to control water and fertilizer supply depending on the growth phase of crops for high yields and quality. This paper reports on our efforts in increasing the yield of tomatoes by using a new medium with air-rich structures and also presents our attempts at IoT-based agricultural production using Sandponics.
Sumitomo Riko Company Limited has developed flexible capacitive pressure sensors, the Smart Rubber (SR) Sensor series, by drawing on the polymer-compounding technology it has developed over the decades. Applying this technology, we have developed an evaluation system for cardiac massage (chest compression) training, Shinnosuke-kun. This system gives real-time feedback on the chest compression depth, tempo (rhythm), recoil, and pressure point during chest compression training. The SR sensor can also evaluate the compression depth with the training mannequin placed on soft materials such as a mattress. We believe that the widespread use of Shinnosuke-kun will contribute to increasing the number of people who can conduct cardiopulmonary resuscitation (CPR) and thereby raise overall survival rates.
With the rising number of electronically controlled devices used in vehicles, the demand for ECUs (electronic control units) has been increased, and it is now required to configure an in-vehicle LAN (local area network) that connects multiple networks. In the past, multistage networks were formed using a two-channel gateway ECU that connects two different networks, making vehicle communication design complicated. We developed a central gateway ECU that is equipped with six network interfaces to relay communication data between channels. This central gateway ECU secures the independence of respective systems, resulting in a simple communication design even with many ECUs being connected. The central gateway ECU, the main ECU for the in-vehicle LAN, allows Sumitomo Electric Industries, Ltd. to offer vehicle infrastructure systems in combination with wiring harnesses and junction boxes.
Silica-based highly nonlinear fibers (HNLFs) are promising platforms for a wide range of applications utilizing fiber nonlinearities, such as broadband light sources, fiber lasers, amplification, all optical processing, sensors, metrologies, and spectroscopies. The key challenges for their practical applications are tailoring the chromatic dispersion, including higher-order dispersion, as well as high nonlinearity, low fiber attenuation, and low splice loss to standard single mode fibers. This paper outlines our silica-based HNLFs, which are designed specifically for desired applications, featuring HNLF with a longitudinally uniform zero dispersion wavelength and HNLFs with optimized fourth-order dispersion. We also demonstrate an accurate chromatic dispersion measurement and present two types of optical frequency combs that use our silica-based HNLFs as application examples.
To cope with the growing data traffic in the short-reach interconnects used for parallel processing in supercomputers and data centers, optical interconnect technologies for broadband high-density transmission are intensively researched and developed. Sumitomo Electric Industries, Ltd. developed, for the first time, a multi-core optical fiber (MCF) that has eight cores compatible to the standard single-mode fiber in O-band with low inter-core crosstalk in the standard 125-μm-diameter glass cladding. The developed MCF is suitable for the short-reach interconnects and enables low-distortion signal transmission in O-band. The standard 125-μm cladding provides high mechanical reliability equivalent to the standard optical fibers and enables the use of conventional technologies in cabling and so on. A high-density fiber optic interconnect cable fabricated with the 12 pieces of the developed MCF realized good optical properties and robustness against the mechanical and thermal stresses.
With the development of mobile networking along with the spread of machine-to-machine communication and the internet of things concept, optical communication devices have been used in various environments including outdoors. This has created the need for optical connectors that can withstand harsh environments while supporting multiple interfaces. To meet this demand, we have developed a waterproof optical connector that is compatible with multiple interfaces. Coming with the IP68 rating, the connector is highly resistant to dust and water, and thus suitable for outdoor use. The product can also be connected easily to SC, LC, and MPO (multi-fiber push on) connectors, as well as to SFP (small form-factor pluggable) transceivers.
With the rapid increase in communication traffic, digital coherent communication technology has spread, particularly for trunk networks. For the application of the technology to metropolitan area networks and data center interconnection, compact and high-power light sources that enable high-density mounting in communication units are required. We have developed a microintegrable tunable laser assembly (Micro-ITLA) using a tunable distributed amplification chirped sampled grating distributed reflector (TDA-CSG-DR) laser that achieves the industry’s highest output power of +18 dBm.
We have been providing advanced broadband technology and internet access equipment to the market. FSU7100 is our latest product that aims for the next generation high-speed transmission service. We offer 1G-EPON (Ethernet passive optical network) cards, 10G-EPON cards, and aggregation switch cards for FSU7100. This paper reports on the specification parameters of the common framework of sOFIA (Sumitomo Electric optical fiber access system integration architecture), line cards, and switch cards. In addition, as a software feature that enables operators to replace DOCSIS (Data over Cable Service Interface Specifications) systems with PON systems at low cost, DPoE (DOCSIS provisioning of EPON) is introduced.
Gas sensing using Quantum Cascade Lasers (QCLs) as a light source is expected to offer a high sensitivity, a short measurement time, and a good portability compared to conventional sensing methods. We have studied low power consumption 7 μm wavelength QCLs for realizing a portable sensing apparatus. The performance of our Distributed Feedback (DFB) QCL in gas sensing was evaluated by measuring the mid-infrared absorption spectrum. In this evaluation, a multi pass type gas cell was used for gas absorption, and for sweeping lasing wavelength of QCLs, the injection current of the DFB-QCL was swept. First, we measured the absorption spectrum of the room air, and found the absorption lines of water and methane to agree well with our simulation results. We then evaluated the sensitivity of the apparatus using a methane gas of a certain amount of concentration, and achieved a high sensing sensitivity of 17 ppb at a DFB-QCL power consumption of less than 3 W.
The drastic increase in internet traffic has created the demand for ultra-high speed optical fiber communication systems that can transmit at a speed of over 400 Gbit/s. InP-based double heterojunction bipolar transistors (InP-DHBTs) with a high-speed transmission capability and high breakdown voltage are suitable for integrated circuits (ICs) that drive the semiconductor lasers or optical modulators in these fiber communication systems. In general, InP-DHBTs must be driven under a high current density for high baud rate operation. However, such severe operating conditions eventually accelerate the degradation of InP-DHBT characteristics because of self-heating, leading to shorter life of ICs. This paper introduces our trials to fabricate InP-DHBTs on a SiC wafer with high heat dissipation. Atomic diffusion bonding, which allows metal-metal bonding under room temperature and low pressure conditions, is used to fabricate the InP-DHBTs on a SiC wafer. The fabricated device reduces thermal resistance by more than 40% owing to the high heat dissipation of the SiC wafer.
Porous polytetrafluoroethylene (PTFE) was invented by Sumitomo Electric Industries, Ltd. using its stretching technology, and has been widely used for POREFLON microfiltration membrane or other products. Porous PTFE filters are particularly advantageous for the filtration of chemicals such as strong acid or alkali and, therefore, commonly used in the manufacturing process of semiconductor wafers, flat panel displays, and other electronic components. To enhance the cleanliness, PTFE membranes need to have smaller pores. This paper describes our new technology for generating nano-sized pores, alternative to the conventional stretching technology, and the resultant nanoporous PTFE membrane.
Silicon Carbide (SiC) devices are promising candidates for high power, high speed, and high temperature switches owing to their superior properties. We have been developing SiC based 3,300 V class metal-oxide-semiconductor field-effect transistors (MOSFETs) and schottky-barrier diodes (SBDs). Stray inductance in the module and the great current changing rate with high speed switching may cause excessive voltage overshooting. Although equivalent circuits are effective for stray inductance analysis, previous equivalent circuit studies covered only a partial area of the entire module. This paper proposes a new method for the dynamic characteristics analysis using the precise equivalent circuit of the entire module.
High thermal oxidation resistance and gas diffusion performance are required for the current collectors of solid oxide fuel cells (SOFCs). The authors have developed a Ni-Sn porous metal that has a high thermal oxidation resistance and gas diffusibility. In this work, the authors have evaluated the applicability of the Ni-Sn porous metal as the cathode collector of an SOFC in terms of the long-term durability, area-specific resistance, and power density. The Ni-10wt% Sn porous metal showed a weight increase of 0.14 mg/cm2 and an area-specific resistance of 0.017 Ωcm2 after withstanding a temperature of 600 °C for 3,000 hours. Thus, it is concluded that the Ni-Sn porous metal can be applied as the cathode collector for SOFCs operating in an intermediate temperature range. The authors have also tested the applicability of the Ni-Sn porous metal and the conventional Ni porous metal as an anode collector. Both the Ni-Sn and the Ni porous metals exhibited favorable compression characteristics and high power densities, equivalent to a Pt mesh, indicating that these metals are ideal as anode collectors, particularly at 800°C.
The recent needs for safe and secure automobiles and energy-saving appliances have increased the demand for high-efficiency motors and high-sensitivity sensors. While the performance of these devices largely depends on the intrinsic properties of the magnet materials used in such devices, it is also important to improve the flexibility and durability of the magnet in order to form them into complicated shapes and use them in high temperatures or severe environments. Although resin-bonded Nd-Fe-B magnets are known for their good formability, they lack in durability due to the poor heat resistance of resin. To overcome this challenge, we have developed a new process that enables the net-shaping of plastic deformable magnet powder and created a resin-free bonded Nd-Fe-B magnet with a high heat resistance.
Midwavelength infrared (MWIR: 3-5 μm) detectors with high sensitivity and fast response are strongly demanded for hazardous gas detection and satellite observation. In recent years, InAs/GaSb superlattices (SLs) have been a subject of intense study as the absorption region of the MWIR detector. Although organometallic vapor phase epitaxy (OMVPE) is advantageous for mass production compared with molecular beam epitaxy (MBE), the number of reports on the OMVPE growth of InAs/GaSb SLs is limited. In this work, we fabricated high-quality 100-period InAs/GaSb SLs on GaSb substrates by OMVPE. MWIR detectors with 100-period SLs showed a dark current density of 2 × 10-4 A/cm2 at -50 mV and 77 K, and an external quantum efficiency of 15% at 3.5 μm and 20 K. These results indicate that the InAs/GaSb SLs could offer excellent structural and electrical properties for high-performance MWIR detectors.
In the 1920s, the electric wire factory of Sumitomo Electric Industries, Ltd.'s Osaka Works introduced fast wire-drawing equipment in anticipation of a substantial improvement in productivity. However, in the drawing process, the die*1 through which the copper was pulled was made of steel. The factory faced the problem of reduced die life due to the low wear resistance of steel. The dies could not withstand the high speed of the equipment and quickly wore out. Consequently, the operators needed to stop the equipment frequently for die replacement. The operating rate of the fast equipment remained low, contrary to expectations.
Recently, environmental awareness has been growing worldwide, and energy saving vehicles, such as hybrid vehicles (HVs), and clean energy generated by solar and wind power are being promoted. Electrical operating systems and electric power devices are necessary for these applications, and electromagnetic conversion parts that are comprised of cores and windings are the key parts for them. While laminated steel and ferrite core are conventional materials for the cores, for downsizing these systems and devices and improving their power efficiency, we have developed a soft magnetic powder core (SMPC), which exhibits superior magnetic properties in a high frequency region and a high degree of forming freedom. Moreover, we have put it into practical use as an HV reactor, etc. The SMPC is produced by press-forming powder with an insulator film. In order to improve its magnetic performance, the modification of magnetic particles composition and the elimination of impurities are effective. In addition, the development and modification of insulation films, coating technologies, and additive materials such as lubricants and binders are also important. Our Fe-Si-Al alloy core exhibits superior characteristics of iron loss.
Cemented carbide was first commercialized by our company in 1928 for use in wire drawing dies. It has since been developed as a base material for cutting tools. First, titanium carbide was added to make the tools suitable for steel cutting, and then the ACE layer technology was developed in order to toughen the cemented carbide substrate. Zirconium was added to cemented carbide substrates in response to user requests for efficient machining. Meanwhile, cermet, base material that consists of a hard titanium phase and was originally created for use in jet engines, was developed for cutting tools because of their low reactivity with steel and fine cutting surface. Although toughness was an issue with cermet, it was solved by nitrogen doping. The subsequently developed surface hardening technology further improved their toughness and wear resistance, and thereby cutting performance. This paper details the history of the development of Igetalloy cemented carbide and cermet.
We have succeeded in the production of novel ultra-hard materials: single-phase (binderless) nano-polycrystalline diamond and nano-polycrystalline cubic Boron Nitride (cBN). These nano-polycrystals were synthesized under static ultra-high pressure and high temperature using a new method, direct conversion sintering. The new hard materials consist of fine grains of several tens of nano-meters without containing any secondary phases or binder materials. They thus have high hardness and high strength that surpass those of single crystals and conventional sintered compacts containing binder materials. The fine microstructure containing no secondary phases and the outstanding mechanical properties of these new hardmaterials are promising for applications to next-generation high-precision and high-efficiency cutting tools.
Valve springs are one of the automobile engine components that require a very high degree of fatigue strength and heat resistance. With the recent trend toward lighter cars and smaller engines, oil tempered wire used for valve springs needs to be smaller in diameter and higher in strength. About 80 years ago, Sumitomo Electric Industries, Ltd. started the production of piano wire, and has since been working hard to develop new materials and techniques for manufacturing steel wire for valve springs. This paper describes the history of the development of high-strength steel wire and its future.
Tungsten is a chief ingredient of hardmetal materials. Since its sources are concentrated in China, the supply of tungsten is highly volatile, and therefore, a reduced dependence on China would stabilize the hardmetal business. In view of this, the Sumitomo Electric Group focused on recycling tungsten from used hardmetal tools. The group developed an efficient recycling technology with a low environmental load, and industrialized the technology in a joint research project. Despite various challenges that came up on the way to industrialization, the group succeeded in establishing the technology as a business. This paper mainly describes the developed technology, which reduces toxic emissions and removes impurities. Our goal now is to recycle even low grade tungsten scrap, most of which is currently being disposed, and thus contribute to a more efficient use of rare metals.
Coated cemented carbide inserts have well-balanced wear resistance and chipping resistance compared with uncoated inserts made of other materials. Consequently, the shipment of coated cemented carbide inserts is increasing with each passing year. Coated cemented carbide inserts account for over 70% of all the inserts currently in use, and this trend seems to continue for many years to come. Sumitomo Electric Industries, Ltd. started research and development on coated materials 50 years ago, and has since been working hard to advance the innovation of chemical vapor deposition and physical vapor deposition coating technologies. This paper looks back at 50 years of history of coated materials development and introduces new materials.
The simulation of chip formation processes was started as a method to construct cutting theories or understand cutting phenomena and has recently been used for actual applications. On the other hand, it is still difficult to simulate all cutting processes with sufficient accuracy because cutting processes are conducted under high temperatures and pressures at high deformation speeds. In this paper, we explain the history of the chip formation simulation and its application examples for cutting tool development. We also discuss what to consider when using the simulation.
Diamond-like carbon (DLC) is a hard material with lubricity and chemical stability. Amid the growing awareness of environmental problems in late years, DLC films have been used to reduce the fuel consumption of automobiles by reducing friction loss. The films are also used as a coating of cutting tools for aluminum alloys that have been widely used for automobile weight reduction. Nippon ITF Inc. provides DLC films most suitable for the customer needs by utilizing its equipment, systems, and expertise. This paper introduces the history of DLC manufacturing processes and DLC films that we have commercialized.
Internal gear rotors are powder metallurgy parts widely used in automobile engine oil pumps, automatic transmissions (ATs), continuously variable transmissions (CVTs), and hybrid vehicle transmissions. In the 1980s, Parachoid rotors were developed and started to be used in automobile oil pumps to meet the growing needs for smaller and lighter oil pumps that achieve improved fuel efficiency. Recently, Megafloid, Geocloid, and Parachoid EX rotors have been developed to meet the needs for even smaller oil pump rotors to reduce friction loss. This paper introduces the development and evolution of these oil pump rotors.
In recent years, industrial application of laser hardening has been made possible due to technological advancements, resulting in lower equipment cost of laser oscillation machines. Laser hardening utilizes surface hardening technology through laser irradiation and generates less heat than induction hardening. Another advantage of laser hardening is its ability to harden the local areas that are not accessible by induction hardening. The use of this technology on sintered parts will lead to new applications due to its inherent advantage in near net shape manufacturing. Laser hardening was performed on various types of sintered materials, and the parts were evaluated for process optimization. Laser hardening was also performed on products in various shapes that are difficult to harden with other surface hardening techniques. The application of this technology for a wide range of products was also investigated.
Powder metallurgy is a processing method whereby green parts are compacted using dies and sintered .It offers equivalent strength as cast iron and superior design flexibility, and produces near-net shaped parts at lower costs as it reduces the need for machining process. For these reasons, powder metallurgy has expanded its market as a result of VA*1 applied to cast iron parts. However, while compaction tooling offers design flexibility in two dimensions, it has difficulty in producing parts with height (in the Z-axis direction) due to ejection constraints. We have introduced bonding technology to compaction tooling using powder metallurgy and achieved design flexibility in three dimensions. This paper describes the characteristics of bonding parts and details assurance methods for bonding areas in our current production.
Diamond cutting tools are used for various applications in nonferrous metal processing as they have superior sharpness and excellent wear resistance. Ultra-precision diamond cutting tools made of single-crystal diamond are used for processing resin molds for optical disk pickup lenses and smartphone camera lenses, as well as optical prism molds for liquid crystal panels. These tools are also used for the ultra-precision processing of laser reflecting mirrors in optical components. Meanwhile, a fiveaxe cutting machine that can operate in the 1-nm level was developed. To be employed for this machine, high-precision and small diamond cutting tools are required. This paper describes the characteristics of the ultra-precision diamond cutting tool (UPC) made of synthetic single crystal diamond named “SUMICRYSTAL.” It also introduces the applications of UPC in the ultraprecision processing of the optical components that Sumitomo Electric Hardmetal Corporation produces.
Diamond cutting tools are used for various applications in nonferrous metal processing as they have superior sharpness and excellent wear resistance. Ultra-precision diamond cutting tools made of single-crystal diamond are used for processing resin molds for optical disk pickup lenses and smartphone camera lenses, as well as optical prism molds for liquid crystal panels. These tools are also used for the ultra-precision processing of laser reflecting mirrors in optical components. Meanwhile, a fiveaxe cutting machine that can operate in the 1-nm level was developed. To be employed for this machine, high-precision and small diamond cutting tools are required. This paper describes the characteristics of the ultra-precision diamond cutting tool (UPC) made of synthetic single crystal diamond named “SUMICRYSTAL.” It also introduces the applications of UPC in the ultraprecision processing of the optical components that Sumitomo Electric Hardmetal Corporation produces.
Sumitomo (SEI) Steel Wire Corp. developed an epoxy coated and filled 15.7 mm ultra-high strength prestressing (UHSP) strand consisting of 7 wires. The UHSP strand is approximately 20% stronger (2,230 MPa) than the conventional strand (1,860 MPa). Through its experience and expertise, the company has recently developed large-diameter UHSP strands: a 29.0 mm 19-wire strand and 17.8 mm 7-wire strand. These strands prevent delayed fracture by the epoxy or high-density polyethylene coating, and thus contribute to high-durability concrete bridges. This paper describes the features of the 29.0 mm 19-wire UHSP strand with pre-grout tendons and epoxy coated and filled 17.8mm 7-wire UHSP strand.
A new voltammetric method using a strongly alkaline electrolyte (SAE; i.e., 6 M KOH + 1 M LiOH) as the supporting electrolyte was developed for the quantitative characterization of copper corrosion products. Conventional chronopotentiometric method using 0.1 M KCl as the electrolyte has been most frequently used for selective determination of copper oxides (Cu2O and CuO) formed on copper surfaces. However, there have been two serious problems. One is the conflicting view regarding the order of reduction of the oxides, and the other is the poor separation between Cu2O and CuO. In 2001, the author successfully employed SAE to achieve a perfect separation of the reduction peaks of the two oxides. It was then found that the oxides were reduced in SAE according to a thermodynamic order, i.e., “CuO → Cu2O.” It has also been shown that the developed method with SAE can be applied to analyse various corrosion products including Cu2S, Cu(OH)2, and also patinas. Use of the developed method has allowed researchers to clarify the mechanism of the atmospheric corrosion of copper.
Optical interconnection has been increasingly required for data center applications and high performance computers. The standardization of the new multi-fiber connector for 40/100G Ethernet, 32 multi-fiber push on (MPO), is progressing to support high-speed, high-bandwidth applications. We have developed a 32 mechanically transferable ferrule for a singlemode fiber, which requires higher precision than a multi-mode fiber. Using the ferrule, the 32 MPO connector operated at an optical insertion loss of below 0.37 dB at random mating when applying 9.8 N compression springs.
High-speed and small-sized transceivers are strongly required to support the rapidly growing internet traffic. The CFP (100G form-factor pluggable) using four-wavelength LAN-WDM (wavelength division multiplexing) is now widely used. To increase the transmission capacity of a line card, CFP4, a very small transceiver, has been standardized. To support this trend, we have developed a 100Gbit/s compact optical transmitter module for CFP4 and integrated a compact low-loss optical multiplexer, a quad-channel laser diode driver, and four laser diodes. The module achieves clear eye openings at low power consumption. This paper describes the design and basic characteristics of the module.
"One of the keys to enhancing optical networking capacity is increasing the number of optical transceivers on a network card. A new compact optical transceiver called “CFP4” has been developed for 100 Gbit/s systems. Because of a compact integrated optical transmitter and receiver, the size of the transceiver is less than 1/6th in comparison with the conventional 100 Gbit/s CFP transceiver. Its power consumption is less than 5.3 W at any operating case temperature by leveraging the multi-channel shuntdriving technique. The small size and low power consumption contribute to the expansion of the transmission capacity of the network card. The transceiver complies with IEEE (Institute of Electrical and Electronic Engineers) standards and CFP MSA (Centum gigabit Form factor Pluggable Multi-Source Agreement) specifications. The CFP4 transceiver supports the same management interface as the CFP transceiver, thus making it possible to reuse existing firmware. Additionally, the CFP4 transceiver newly implements in-service firmware upgrading. This paper describes the superior optical and electrical properties of the transceiver as well as some of the design features."
This paper describes a new ultra-compact multi-fiber push-on (MPO) connector for data centers that are increasing rapidly in number with the expansion of data traffic. In these data centers, many devices, such as switches, servers, and storage units, are connected with metal wires and optical fiber cables. For flexible cabling, the structured cabling system (SCS) has been introduced, and the MPO connector is the key device for a high-density and large-scale SCS. Our user-friendly round-cord-type MPO connector supports gender change and polarity change.
The flexible printed circuit (FPC) is commonly used in electronic equipment including portable devices. Due to its thinness and lightness, the FPC is being increasingly used for LEDs and in-vehicle applications. For these uses, however, the major problem is long-term reliability at high temperatures: whereas the FPC needs to be heat resistant up to 100°C for use in electronic devices, LEDs and in-vehicle applications require a higher resistance up to 150°C. Sumitomo Electric Industries, Ltd. has developed an adhesive with high heat resistance and thus created an FPC that withstands up to with 150°C.
Connectors are widely used to connect flexible flat cables (FFCs) with printed circuit boards (PCBs). In recent years, demand for a direct connection of FFCs with PCBs has been increasing due to the downsizing of electronic devices such as wearable components. An anisotropic conductive film (ACF) can be used for such a connection, however, there exist some difficulties in the bonding operation and the shelf life. We have developed a low-profile, easy-bonding interconnection that eliminates the need for connectors and is highly reliable. This achievement was made possible with our original conductive paste and highresolution printing technologies.
We have developed a novel ultracompact RGB laser module with a wide operating temperature range. RGB laser chips, photodiode chips, a thermistor, and optical components are mounted on a thermo-electric cooler on a base mount. The base mount is hermetically sealed in an 11 × 13 × 5.7 mm metal package, from which high-quality stable collimated laser beams are emitted. Operation at +85°C was difficult with conventional RGB laser modules because the output power of laser diodes (LDs), especially red LDs, dropped at high temperatures. However, the thermal capacity was lowered by mounting LDs on a chip, thus enabled control of module temperature at a wide range of -40°C to +85°C with a Peltier cooler. The temperature is controlled at a high reply speed of less than 4 sec.
Concentrator photovoltaic (CPV) systems are promising power generation systems for their high outputs per module active area and rated power compared with crystalline silicon photovoltaic (Si-PV) systems. In a field test conducted in Morocco, where solar radiation is high, our CPV system demonstrated approximately 2.5 times higher output power per module active area and 1.3 times higher output power per rated power than a Si-PV system under the condition of direct normal irradiation of 7.9 kWh/m2/day. We have developed a tracker that faces the ground during the night, thus preventing soil or sand from accumulating on the glass surface of the CPV module and contributing to high power generation.
Cable racks for electrical wiring in buildings and factories have received a lot of damage during earthquakes compared to those in seismic structures because they are non-structural materials. We investigated the vibration characteristics of the cable racks by shaking test tables in actual use conditions. We then optimized the damping structure of the racks to enable them to hold wires tightly and prevent damage effectively. We also examined the workability of the rack structure for existing buildings.
These days, printed circuit board (PCB) drill tends to be longer and smaller in diameter as the advanced miniaturization and high integration of electric components require smaller holes. In addition, an increasing number of substrates are overlaid for efficient processing. Such drills are easy to be bent and broken, and accordingly the hole position accuracy decreases. To prevent such property degradation, we thoroughly investigated conventional products and discovered that the tissue homogenization of cemented carbide is the key. Through the review of raw materials and optimization of production processes, we succeeded in the development of the high reliability PCB drill material “ZF20A,” thus improving the hole position accuracy and breakage resistance.
"Materials that have a nanoscale pore structure show specific characteristics in absorbing raw materials or ions. This paper presents evaluation results of nano structure carbon materials that were obtained by treating carbide in a chlorine atmosphere. We generated the nano porous structure by processing SiC, TiC, and Al4C3 in a chlorine controlled atmosphere at over 1,000°C. With carbon derived from TiC and Al4C3, graphite structures were formed, and sub-nano pores and crystal growth reduced with increasing treatment temperature. In contrast, SiC-derived carbon did not form a graphite layer structure and maintained subnano pores even at high temperature of 1,400°C. With this process, we can form porous carbon materials with various characteristics by using different raw materials and temperatures. These materials can be used for a wide range of applications such as gas absorption and electricity storage."
One of the main concerns for the security of in-vehicle data is spoofing messages on the in-vehicle network. Controller Area Network (CAN) is the most extensively embedded network protocol in vehicles. In the last decade, security attacks in vehicles have been increasing and have been reported in several papers. Therefore, security measures are expected that meet the requirements of real time and cost constraint for in-vehicle control network. In this paper, we propose centralized authentication system in CAN with improved CAN controller. Our experimental results demonstrate that our proposal method is effective on real in-vehicle network environments.
Automotive electronics have developed significantly in recent years. This trend has increased the number of connectors used, has promoted multi-way connectors, and has required that connector reliability be secured. For the development of highly reliable automotive connectors, it is important to understand the deterioration state of connectors that are actually used in vehicles. In this study connectors were collected from high mileage vehicles (one with 100,000 km mileage, another with 150,000 km mileage) and their deterioration state and possible deterioration factors were investigated. The results showed that the deterioration of terminals progresses in proportion to mileage, but the deterioration level was not on the level that leads to insufficient reliability. In addition, from the observation results of collected terminal surface, the main promoter of deterioration was determined to be fretting wear. Based on this determination, the number of fretting cycles that is equivalent to 100,000 km in mileage was estimated by comparing with the fretting wear test on the bench. As a result, the number of fretting cycles was extremely smaller than expected and its level was sufficient to keep the reliability of connectors.
Our team has developed a degradation model considering the effect of humidity on Young’s modulus of primary coating in the optical fiber, i.e. in situ modulus (ISM), and also established an estimation method for the long-term change in ISM based on the model. This method allows the estimation of ISM degradation at arbitrary conditions of temperature, relative humidity and duration. The derived contour profile of standard degradation duration, which is the duration estimated for ISM to reach a specific retention value by the degradation, and the equation of equivalent conditions are useful tools for the estimation of long-term change in ISM.
We have developed single-mode-fiber (SMF) lensed connectors operable with small mating force and insensitive fine dust on their end faces. 24 SMF lensed connectors utilizing an MT connector technology have been successfully fabricated. The beam is expanded by a graded-index (GI) fiber lens array with a waist diameter of 52 μm, and the spring force in the mating condition can be reduced to 3.3 N, which is about one sixth of that for a 24-MPO connector. The optical fibers and lenses are precisely aligned with a pair of guide pins and holes made by high precision molding technologies. Their average and maximum insertion losses (ILs) are less than 0.7 dB and 1.6 dB, respectively. These have been the best results for singlemode multi-optical-fiber lensed connectors reported so far.
The E-band (71–86 GHz) is highly expected recently, because of the available wide frequency range, to support backhaul systems for cell phone and mobile communication systems at much higher data rate. The performance and cost of the E-band wireless equipment strongly depend on not only the available devices but also the assembly form. Sumitomo Electric Device Innovations, Inc. (SEDI) and Sumitomo Electric Industries, Ltd. have newly developed so called threedimensional wafer level chip size package technology (3-D WLCSP) in order to mass produce microwave and millimeterwave devices and also assemble them simply in the flip-chip fashion. In this paper, we present a low noise amplifier WLCSPMMIC and some of its design detail in comparison with conventional wire-connected planar low noise amplifier MMIC.
Gallium Nitride (GaN) is superior in breakdown voltage and RF performance and is suitable for high electron mobility transistors (HEMTs). Since wireless communication using millimeter-wave E-band (70–80 GHz) features wide bandwidth and large capacity, this system has been expected to function as backhaul communication. Therefore, we decided to develop E-band GaN HEMTs. The HEMT we aimed to develop required exclusive high frequency compared to that of current products that use mainly micrometer-waves (up to 16 GHz). So we had to remarkably improve RF performance. We chose InAlN as a barrier of GaN HEMTs for high transconductance and developed low capacitance gate process, a key technology of RF performance improvement. To reduce gate capacitance (Cgs), Y-shaped gate process with short gate length of 100 nm was developed. With this process, we have obtained extremely low Cgs of 0.58 pF/mm and the current gain cutoff frequency of 110 GHz and realized high RF performance E-band GaN HEMTs.
A high-output power and broadband GaN high electron mobility transistor (HEMT) has been developed for X-band applications. The device consists of 2-dice of 14.4-milimeter gate periphery together with input and output 2-stage impedance transformers. The device exhibited saturated output power of 310 W with power gain of 10.0 dB over the wide frequency range of 8.5–10.0 GHz, operating at 65 V drain voltage under pulsed condition. In addition, the highest saturated output power reached 333 W with power gain of 10.2 dB at 9.0 GHz. This is the highest output power GaN HEMT ever reported for X-band.
Recent years have seen increases in electronically controlled system equipment and electric current capacity. Therefore the demand for switches capable of handling high current is rising. Mercury reed switches have been used for high-current switch until now. Since mercury is a substance of concern, mercury reed switches have been changed to reed switches in which mercury is not used. However, when a temperature rises largely as energization progresses by Joule heat effect, lead wires lose their ability to carry magnetic flux, and reed switches become less sensitive. Due to these problems, reed switches were not used for high-current switches. We have developed cobalt-nickel-iron alloy wire for high-current switches that demonstrate excellent characteristics similar to the conventional alloy lead wire. The new alloy wire suppresses heating due to energization and has high Curie temperature, i.e. less susceptibility to lose magnetic characteristics. The reed switch using the new alloy wire is expected to be applied to LEDs in automobile stop lamps.
Silicon Carbide (SiC) devices are promising candidates for high power, high speed, and high temperature switches owing to their superior properties. We have been developing SiC metal-oxide-semiconductor field effect transistors (MOSFETs) and SiC Schottky barrier diodes (SBDs) of 3.3-kilovolt class. The fabricated SiC power module successfully reduced switching losses to one-third to that of the conventional Si IGBT module. This paper evaluates the performance of a full SiC module compared to the conventional one.
We have developed an energy management system “sEMSA,” which optimally controls multiple power sources based on mathematical programming in customer premises. sEMSA realizes energy cost minimization by newly developed “optimal planning of power sources” and “real time control.” In addition, this system automatically regulates grid incoming power corresponding to the power company's demand requests. We have completed field tests of sEMSA at Sumitomo Electric Yokohama Works and another company's factory. sEMSA for factory use will be released in 2015.
The increase of urban population in recent years results in increased traffic, whereas the interest in environment and energy issues is growing. With the advantage of transporting a larger number of passengers with lower CO2 emissions and consumption energy than automobiles and aircraft, railways are attracting international attention. Railway systems have been constructed around the world and being extended into cold regions such as European countries and China in recent years. Thus, Sumitomo Electric Industries, Ltd. has developed a new air spring for railways designed for cold region transportation. This new air spring successfully operates in very cold environments without sacrificing general properties. The key technology of this new product is the rubber compound formulation technology for diaphragm, which enables operation at a very low temperature with high flexibility.