Members' Profiles

Micro Device Center
Yamatake Corporation
1. Challenge of Micromachine Technology
We have been developing business operations with the aim ofimproving the energy and resource efficiency in buildings, plants, andfactories under the visionary slogan "Providing Greater Comfort for
People and the Earth." To achieve our business goals, sensing andcontrol technologies are essential. Hence, we have placed emphasis on
microelectromechanical systems (MEMS) for developing miniature,high-performance sensors and actuators to be installed on the ends ofmeasuring devices in the field.
We first tackled micromachine technology with the inauguration ofour corporate research center in the middle of 1980. Since then, we
have established a business partnership with Honeywell Inc. (U.S., now
Honeywell International Inc ) for the purpose of researching andcommercializing micromachine technology. Today, we are taking on
both R&D and fabrication of microdevices, from sensor elements topackages, and are functioning as an organization capable of making
microdevices for in-house use available commercially through divisions
products. Since it requires much time and effort to discover new
products and businesses with marketability, a separate organization
has been created in the Research & Development Headquarters toperform exploratory seeds development function.

Shunichiro Awa
Director, Micro Device Center
primarily in air conditioning systems for buildings, while increasingly
attracting the attention of both national and international users.

2) Microflow Sensors
We began full-scale development of thermal flow sensors in the late1980's, with the aim of applying this knowledge to gas flow measurement.
In 1994 we succeeded in mass-producing microflow sensors with 1.7
millimeters square chip. The sensor possesses outstanding features, suchas a high sensitivity capable of measuring a flow rate of 1 cm/sec or less.
We improved the performance and functionality of the sensor throughthe production of numerous prototypes and repeated field tests. Inaddition, we collected and evaluated sensors that had been installed in
the field for more than ten years. Then proved the long term reliability ofour products. Using this microflow sensor, we have developed a highspeed, high-accuracy flow measurement technology for a wide range ofapplications, from ultra low flow rates to high flow rates. In addition,
many results have been obtained by applying this microflow sensor tostudies of flows on wall surfaces.

2. Development of Micromachine Technology
Here, we will introduce some of the microdevices we havesuccessfully developed and commercialized.

1) Humidity sensors
Humidity sensors are next in importance after temperature sensors interms of controlling the air condition in a building. A stable humiditysensitive polymer film was developed through joint research withuniversities conducted over several years, enabling us to develop advanced
humidity sensors. Evaluations conducted by an independent Swiss
institute revealed that our product is superior to other major humidity
sensors in the world in dew point stability and chlorine resistance.
Accordingly, Yamatake humidity sensors are being widely employed,

Humidity sensing elements

3) Pressure Sensors
The most basic targets of industrial measurements are flow rate
and pressure. A pressure sensor measures not only pressure, but also
flow rate calculated based on the pressure differential across thediaphragm, or orifice, formed in the piping. The pressure sensor is theoldest MEMS sensor that has been widely used in industrialapplications. Yamatake has also conducted intensive research anddevelopment since the inauguration of the corporate research centerand the Micro Device Center. We successfully developed pressure
sensors utilizing piezoresistive pressure sensing elements andmarketed them as the world's smallest microprocessor-based pressure
sensors. Our primary pressure sensors have high accuracy and hightemperature stability.
In order to meet the demands for pressure measurements underhigh-temperature and corrosive environments, we developed theSapphire capacitive sensor that can offer excellent resistance to heatand corrosion. The sensor element is produced from 100% sapphireand can directly measure temperatures of several hundreds of degrees,
as well as pressures on corrosive media. Since the development phase,the sensor has received high praise from customers in the finechemical and semiconductor industries. We hope to acceleratecommercialization of this sensor.

Microflow sensing elements

3. Future Challenges

Piezo-resistive pressure
sensing elements

As described above, humidity, flow rate, and pressure are basic
targets of sensing in thefield of measurement and control. We continue to conduct researchand development to meet the needs of our customers. In addition, wewill employ a comprehensive technology accumulated through thedevelopment of in-house microdevices to take a further step toward
developing and producing commercial devices for outside customers.

Sapphire pressure sensingelements

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