Site: Sumitomo Electric Industries, Ltd.
Itami Research Laboratory
1-1-1 Koyakita, Itami-shi
Osaka 664, Japan
Tel: 81-727-71-0610; Fax: 70-6727
Date Visited: January 31, 1997
WTEC Attendees: J. Rowell (report author), M. Beasley, G. Gamota, H. Morishita, M. Nisenoff, F. Patten, R. Ralston
Hosts: Dr. Hideo Itozaki, Chief Research Associate
Mr. Tatsuoki Nagaishi
Dr. Michitomo Iiyama, Osaka Laboratories

BACKGROUND

Sumitomo Electric Industries, Ltd., was founded and has grown over the centuries because of its mastery of materials and their manufacture. Masutomo Sumitomo (1585-1652) was a Buddhist priest, whose disciple and brother in law, Riemon Soga (1572-1636) established a copper business in Kyoto in 1590. Riemon revolutionized Japanese copper refining by perfecting Western methods for removing silver from the copper ore. The Sumitomo Copper Rolling works, established in 1897 to manufacture bare copper wire, spun off the Sumitomo Electric Wire and Cable Works in 1911. Thereafter, the diversification of the company (renamed Sumitomo Electric Industries in 1939) can be traced to new materials: superalloy tools (1931), transmission cable (1949), disc brakes (1963), compound semiconductors (1970), optical fiber (1974), and synthetic diamond (1986). These materials-based businesses have lead to systems interests, such as traffic control systems, telecommunication networks, antilock braking systems, and automobile navigation systems.

One unusual feature of Sumitomo's approach to R&D is the encouragement of in-house ventures ("Shanai-Venture," similar to entrepreneurial ventures in the United States), through which R&D staff are encouraged to commercialize their research ideas. The compound semiconductor business is one such example. In this way "researchers are constantly aware of the commercial potential of research projects." It is interesting to note that the third of the company's business principles, formulated in 1891, "advises against being attracted to easy profits or hastily drawn to the promise of profits before fully investigating the commercial viability of ventures."

The revenues of Sumitomo Electric were relatively flat after 1991, at ¥1.1 - 1.16 trillion (~$9.2 - 9.7 billion). Profits declined from ¥32 billion (~$267 million) in 1992 to ¥20 billion (~$167 million) in 1995. Spending on R&D dropped slightly from a peak of ¥26.5 billion in 1993 (~$221 million) to ¥24.9 billion in 1995 (~$208 million), or about 2.4% of revenues.

R&D ACTIVITIES

Superconductivity R&D is carried out at both the Osaka and the Itami Laboratories. The Osaka work on HTS conductors figured prominently in the report of the 1996/97 WTEC panel on power applications of superconductivity (Larbalestier 1997). In our visit to Itami we met with Dr. Hideo Itozaki and Mr. Tatsuoki Nagaishi of the Itami Laboratories and Dr. Michitomo Iiyama of the Basic High Technology Laboratories.

Shortly after the discovery of HTS, Dr. Itozaki began research on HTS films for microwave applications, and made some of the earliest filters. His films, made by on-axis sputtering, had very high Jcs. However, the laboratory decided to end this program in 1992. From 1990 to 1996, Itozaki and his colleagues represented the HTSQUID activity within the Superconducting Sensor Laboratory (SSL). The HTS devices and systems were made at Itami and sent to SSL for test. Since the end of the SSL activity, the LT and HTSQUID systems in SSL continue to be used for MEG and MCG studies by Professor Kotani from Tokyo Denki University. The MKG system built for SSL by Itozaki's group remains the most complex HTSQUID system built anywhere to date, having 32 channels of flux focusing-type SQUIDs using step edge junctions. Dr. Itozaki feels that the SSL collaboration was a valuable means of obtaining SQUID device and system experience, even though the process of joining SSL (proposals, paperwork, etc.) initially slowed his research activity markedly.

Since the end of SSL activity (March 1996) Dr. Itozaki, funded by the company, has pursued SQUID applications even more vigorously. A small single-channel HTSQUID system is now being sold by Sumitomo (see Figure 6.5, p. 42). This is very similar to Mr. SQUID, which has been sold by Conductus for over 5 years, but the Sumitomo system has a replaceable sensor unit with the SQUID (step-edge junctions rather than bi-epitaxial or bicrystal, as in Mr. SQUID) mounted transverse to the probe. Dr. Itozaki hopes customers will be mainly in industry, so that experience with SQUID NDE, for example, is increased in Japan. The 5 mm x 5 mm sensors are produced eight at a time by laser ablation.

Higher performance sensors for cardiology systems are being made by a flip-chip assembly of the SQUID with a pick-up loop integrated with a 15-turn input coil. The white noise, 13 ft/Hz1/2, is within a factor 2 of the best to date. However, yields of the multilevel coil remain somewhat low, so the flux-focus-type of sensor is still being used in multichannel systems.

In the laboratory, the WTEC panel saw a compact 16-channel cardiology system mounted in a long mu-metal shield (about the size of an MRI machine) to reduce ambient noise. At SSL maps of the electrical activity of both the human heart and stomach have been reported using a similar system. Dr. Itozaki expects to begin collaborative measurements with doctors soon. Another application demonstrated by Itozaki's group and described by Mr. Nagaishi relates to the early history of Sumitomo as a manufacturer of copper wire. For wires being manufactured in the factory with diameters as small as 50 µm, iron particles of comparable diameter are a serious defect. The group has shown that a single channel HTSQUID system can detect such particles even when the wire is moving at 800 m/min. On the factory floor, the speed is 2,000 m/min. (about 75 mph!), but they seem confident that a system with the required bandwidth can be developed and will be of value to the company. Quality control of medicine, food, and fluids was also mentioned for future applications.

In the panel's laboratory tour we saw 4 or 5 laboratories in two buildings, including 2 cleanrooms for sensor fabrication, each with a laser deposition system. A separate cleanroom is used for lithography.

The research Dr. Iiyama described to the WTEC panel, performed in the Basic High Technology Laboratories, is part of 1988-1998 Future Electron Devices (FED) funded program on 3-terminal SC devices. The objective is to modulate the superconducting current and Tc of a very thin HTS film in an FET structure. The WTEC panelists were most impressed by the capabilities of the MBE machine, with many in-situ characterization instruments, such as ISS, which has been built up by Dr. Iiyama. The machine represents a state of the materials and materials measurement art that is common for semiconductor research in the U.S., but is beyond the financial means of anyone engaged in superconductivity. With great rigor, Dr. Iiyama has studied many aspects of multilayer growth in this FET structure, including the preparation of the substrate, the YBCO/STO interface, the quality of the YBCO surface as a function of deposition rate, the question of oxygen loss from the YBCO during later processing, and the resistance of normal metal contacts. The FET requires 2 volts to product a 10% change in drain current at 44 K, and future work is aimed at increasing this modulation.

In a discussion period, WTEC panelists asked about the role of the Osaka laboratory in the Matsushita-Kyocera-Sumitomo "Western Alliance" for wireless applications. Within this collaboration Kyocera is working on the cryogenic package, and the refrigerator will be supplied by a manufacturer (this is the only case of a collaboration not developing its own cryocooler, we believe). Sumitomo's role is to provide 3-inch-dia. double-sided YBCO films on LAO (lanthanum aluminate), made by laser deposition. The microwave design, fabrication of filters, and system testing is done at Matsushita. As Sumitomo had a device level microwave activity in the late 1980s, there seems to be little technical value to the company in this collaboration, although presumably it represents a path to becoming a OEM supplier of films for the wireless market in Japan, if and when that develops.

Sumitomo has 3 people at ISTEC. Our hosts' expressed the view that for fundamental research, the centralized collaboration style of ISTEC works well, but when there is a desire to develop proprietary information in-house, the distributed network of FED is preferable. It seemed unlikely to WTEC panelists that the very high-level (and expensive) thin film materials research carried out by Dr. Iiyama would continue without FED (or other agency) support. Certainly there is no such work in the U.S. SCE industry.

It is clear that Dr. Itozaki would like to follow the Sumitomo tradition of "spinning-out" a small SQUID company. Given his demonstration of a number of products and potential products, this would seem quite possible.


Published: August 1998; WTEC Hyper-Librarian