Norio Ichikawa

Semiconductor capacitance-type accelerometer with PWM electrostatic servo technique

Abstract A new semiconductor capacitance-type accelerometer utilizing a pulse width modulation (PWM) electrostatic servo technique has been developed. Highly accurate detection of feeble and low frequency acceleration became possible with the PWM sensing method. The limited air gaps between the movable and fixed electrodes ensured compatibility between high sensitivity and durability, while transverse sensitivity was reduced due to the symmetric structure of the sensing part.

Highly reliable silicon micromachined physical sensors in mass production

Abstract Silicon micromachined physical sensors such as silicon pressure sensors and accelerometers are now in mass production in response to the strong market demands. In the design of such sensors, it is most important to guarantee high reliability as well as low cost. To respond to these demands for microsensors, the designs of device structure, production processes and packaging have been investigated in detail.