新型高量程冲击硅微机械加速度传感器的设计与制造

Design and fabrication of novel high-impact silicon micro-mechanical accelerometer

给出了一种测量高量程冲击加速度的硅微机械加速度传感器的设计和制造方法．加速度传感器采用整体式悬臂梁结构，在硅片平面内设计了两个分布方向相反结构相同的悬臂梁，每个悬臂梁顶端通过硼扩散形成两个压敏电阻，四个压敏电阻构成惠斯通全桥连接．悬臂梁两侧面和过载保护曲面采用DRIE技术加工，过载保护曲面设计成近似于冲击加速度传感器承受最大加速度时悬臂梁弯曲曲面的形状，一方面提高了悬臂梁过载保护能力，另一方面可以调节加速度传感器的工作阻尼至临界阻尼，有效提高了加速度传感器的工作频率带宽．分析和测试结果表明，加速度传感器的灵敏度达到3．024μV／g，工作频率带宽达到O～81kHz，量程达到0～50000g．加速度传感器的性能能够满足测号冲击过程的要求．

The design and manufacturing method of a novel high-impact silicon micro-mechanical accelerometer is presented in this paper. A whole-beam structure is used in this accelerometer. In this aceelerometer, the two cantilevers with the same structures and the opposite distribution directions in the silicon plane. There are two varistors formed by boron proliferation on the top of each cantilever. The four varistors form the Wheatstone full bridge. Two lateral sides of cantilever and overload protection structure are fabricated using DRIE technology. A novel overload protection curvature is designed to be similar to the cantilever bending shape which is bearing the greatest acceleration. This design increases the overload protection and improves the vibration damping of accelerometer to the critical damping. The working frequency bandwidth of accelerometer is increased effectively. The experiments show that the sensitivity of accelerometer reaches 3.024μV/g, the working frequency bandwidth changes from 0 to 81 kHz and measuring scope changes from 0 to 50 000 g, the performances of accelerometer can meet the demands of impact measurement.