MEMS Foundry Service at Matsushita Electric Works
Kazushi Tomii, Group Leader of Prototype Fabrication
Advanced MEMS Development Center
Matsushita Electric Works, Ltd.
Owing to this development, MEW developed avertical silicon etching technique using Deep RIE forforming through-holes and micropatterns in wafers
and achieving high aspect ratios, and silicon-oninsulator (SOI) bulk micromachining techniques for
performing precision processing on a submicron orderusing SOI wafers formed by wafer bonding. These
technologies enable the fabrication of smaller devices
with higher performance.

1. Outline
Since 1981, Matsushita Electric Works (MEW) has
developed and accumulated knowledge in technologies
involving semiconductor devices, such as relay
devices, for in-house applications. From the mid1990s, the company began developing MEMS devices
in earnest, including pressure sensors andaccelerometers, and later put its in-house facilities touse by launching the MEMS foundry service in 2002.
MEW offers a wide range of services from wafer
processing, using bulk micromachining techniques (amicromachining technology for producing complex 3D
structures through Deep-RIE on silicon substrates andwafer bonding) accumulated through in-housedevelopment of MEMS products, to packaging.
Through its rich experience in mass-producing MEMS
sensors, the company can provide total solutions fromprototyping to mass-production.

3. Features of the Foundry Service
MEW's foundry service performs a wide range ofservices from single-wafer processes to device fabricationand packaging. In addition to the technologies describedabove, the foundry can produce various 3D structures bycombining nanopatterning with a semiconductor stepper,
glass substrates processing, and bonding steps. MEW also
possesses a packaging technology fostered through thedevelopment of various in-house devices and can offer
services applying a micropackaging technology using
molded interconnect devices (MID; a technology tomanufacture 3D electric circuits directly on injection
molded boards).
MEW possesses fabrication and quality assurance
knowledge founded on a wealth of experience fromdevelopment to mass-production of in-house products.
Based on this know-how, the foundry offers services fromdesign and small-quantity prototype fabrication to design
studies for mass-production and actual mass-production.
MEW can perform services from development andprototype production to small-quantity production on its
4-inch line at the Advanced MEMS Development Center,located at the Kadoma headquarters in Osaka, andpossesses a 6-inch line for mass-production at its Ise Plant
in Mie Prefecture.

2. MEMS Technology at Matsushita Electric Works
For many years now, MEW has developed andcommercialized various MEMS products with a focus
on bulk micromachined MEMS sensors. Applying
anisotropic etching of silicon, developed throughprocessing semiconductor relays, MEW has usedpiezoresistive pressure sensors in such consumer
products as blood pressure monitors, and has
employed single-axis accelerometers of the same
piezoresistive type for automotive uses. To date, thecompany has also developed three-axis
accelerometers, and actuators used for MEMS opticalswitches, MEMS relays, and microvalves.

Microvalve

4. Conclusion
In addition to using its MEMS processing technologies
developed and accumulated thus far for in-houseproducts, MEW also hopes to accelerate the practical use
and applications of MEMS by extensively providing thesetechnologies to users trying to develop MEMS businesses.
Through assistance from NEDO, MEW is participatingin the MEMS Project, a three-year endeavor that began in
2003, developing new MEMS processing technologies.
The company aims to further develop and expand its
foundry services in the future.

MEMS relay
Single-axis accelerometer
Pressure sensor

Optical switch

Three-axis
accelerometer

STotal production: 1.5 million
SApplications: in-vehicle sensors SUnder development
STotal production: 22 million
SApplications: blood pressure monitors and pressure gauges

MEMS development at Matsushita Electric Works

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