高过载加速度敏感芯片的结构与特性

Structure and Characteristics of High Overload Acceleration Sensitive Chip

为满足极端应用情况对高过载加速度传感器的需求,设计了一种带有微梁的加速度敏感结构。通过对主梁和微梁应力分布及敏感结构固有频率的仿真分析,给出了该敏感结构的设计方法,以此确定了传感器的结构参数。基于单晶硅材料断裂强度的尺寸效应,分析了敏感结构的过载特性。仿真结果表明,微梁的引入极大改善了加速度传感器的过载能力,所设计量程为1 g的加速度敏感芯片,其满量程输出约为40 mV,过载可达79倍量程。

In order to meet the requirements of high overload acceleration sensors for extreme application conditions,an acceleration sensitive structure with micro-beams was designed.Through the analysis for the simulation of the stress distribution of the main-beams and the micro-beams and the natural frequency of the sensitive structure,the design method of the sensitive structure was proposed,and the structural parameters of the sensor were determined.Based on the size effect of the fracture strength of monocrystalline silicon,the overload characteristics of the sensitive structure were analyzed.The simulation results indicate that the overload capacity of the acceleration sensor was improved significantly by introducing the micro-beams.For the acceleration sensitive chip with a full range of 1 g,its full scale output voltage is about 40 mV,and overload can reach up to 79-fold of the full scale.