Site: Nippondenso Research Laboratories
500-1 Minamiyama, Komenoki
Aichi-ken 470-01, Japan
Date Visited: September 30, 1993
Report Author: G.B. Hocker
Dr. Tadashi Hattori General Manager
Takashi Kurahashi Project Manager
Dr. Nobuaki Kawahara Researcher
Dr. Masao Nagakubo Researcher
Kunihiko Sasaki Researcher
Nippondenso is a major manufacturer of automobile components worldwide -- number one in Japan and number three worldwide -- with sales of over $12 billion and recent income of $400 million. Nippondenso was founded in 1949, and is part of the Toyota group of companies. Nippondenso Research Laboratories were established in 1991 and employ 300 people, 170 of whom are researchers. Research fields include semiconductors, control systems, robotics, micromachines, artificial intelligence, and biomaterials. The seven-story laboratory building has much space available for expansion. The connected test center buildings have two Class 10 clean rooms.
The panel was greeted by Dr. Tadashi Hattori, the general manager. An introductory video tape showed Nippondenso's microcar activities. Dr. Nobuaki Kawahara led much of the discussion. About thirty people work on micromachining and about ten on their part of the national micromachine project.
Their first target for MEMS technology is sensors; the second target is for small optical devices where large forces and mass are not required. Major efforts have focused on an integrated pressure sensor for engine control, and on an integrated air bag crash sensor. The former is a piezoresistive diaphragm device 2.8 mm square. The latter is based on an etched cantilever with piezoresistors, 8.3 x 3.6 mm, and packaged in silicone oil for damping. Both use extensive on-chip circuitry. A clever Si diaphragm, variable focus mirror was shown. It is electrostatically deflected, and the properly shaped optical surface is obtained by varying the diaphragm thickness with complex micromachining according to a design reached by FEM analysis. Bar code readers, a Nippondenso product, were said to be the application.
An extensive laboratory tour also included demonstrations of the microcars in operation, a miniature microwave-powered plane, and thin film electroluminescent displays in orange-yellow, red, and green, planned for production in a few years. Posters described Si wafer bonding for sensors, power devices and ICs, and laser microetching of PZT in pure water with a Nd:YLF laser. Also demonstrated were an inchworm actuator based on electromagnet relays, and development of technology for bonding Si wafers to aluminum.
In subsequent discussions, Nippondenso researchers indicated that their primary interest is in micromachining technology developments. They are using bulk micromachining and trying to get surface poly-Si micromachining wafer bonding technology into production. They believe LIGA is very expensive, limited in the types of materials it can use, and cannot make truly 3-D surfaces. They are concentrating on piezoelectrics and electrostatics for miniature actuators, since these do not produce heat. Their work in the national (MITI) micromachine project is on sensors and actuators, concentrating on materials other than Si, such as piezoelectrics. They work with several university professors on sensors and actuators, wafer bonding, and amorphous Si, but do not send their researchers to the universities. An estimated typical time to market a new technology was: two years to develop a research prototype, four additional years to develop an engineering prototype, and four more years to introduce the final product in the marketplace.
Creative Research Lab brochure (mostly in Japanese).
Nippondenso Corporate Guide.
Ohtsuka, Y., et al. "Three-dimensional Pattern Recognition by Range Finder with Laser Beam Sensor."
Saeki, K., et al. 1992. "Aberration Reduction of Si Diaphragm Dynamic Focusing Mirror." Paper presented at Third International Symposium on Micro Machine and Human Science. 14-16 October. Nagoya, Japan. (Also presented at MEMS '93).
Tesigahara, A., et al. 1992. "Fabrication of a Shell Body Microcar." Paper presented at Third International Symposium on Micro Machine and Human Science. 14-16 October. Nagoya, Japan. (Note that full proceedings were provided by University of Nagoya).