Abstract
An SOI (Silicon on Insulator) angular rate sensor with an open beam structure (OBS) has been designed and fabricated. To obtain good performance of the sensor, the FEM (Finite Element Method) analysis was carried out for several types of sensor structures to evaluate the vibration stability of the sensor. The stability of vibration modes was investigated by defining the independency between the excitation and detection vibration modes of the sensor structures. The FEM results showed the proposed OBS improved the independency by 60 times compared to the conventional structure.
The OBS also made it possible to wire from electrodes beside the mass of the sensor to exterior bonding electrodes by mono-layer silicon on the SOI. Due to the easy wiring, the process became simple and low cost. The size of the sensor element was 1mm × 1mm × 0.5mm, and good linearity within +/- 0.5 % of the sensor output was obtained. The experimental results showed that the OBS provided fine sensor features; good stability in wide temperature range, and high precision. Therefore, this sensor is suitable for automotive applications, and has attained to mass production.
