一种高精度MEMS梳齿驱动器有限元仿真方法及实验

摘要

为解决目前MEMS梳齿电容驱动器由于边缘效应导致的理想计算模型计算误差较大问题,利用有限单元法中的能量法,提出了一种对梳齿驱动器电容量进行精确仿真计算的方法并以实际制作的微机械陀螺质量块上的90对梳齿驱动器为对象,分别利用该方法及常用的CMATRIX仿真方法对其电容值进行了仿真计算.两种方法得到的电容量的计算结果分别为1.5283pF和1.5793pF.二者与利用高精度LCR测试仪得到的结果1.5172pF的相对误差分别为0.73％和4.09％.实验结果表明,该方法对考虑边缘效应的MEMS梳齿电容驱动器具有较高的计算精度.%A new simulation method is introduced to solve the problem of high calculating errors of the ideal model caused by the edge effect for MEMS (Micro-electromechanical System) comb capacitor. In this method, the energy method in FEM (Finite Element Method) is used and the MEMS comb actuator (90 pairs of comb teeth) which is fabricated on a MEMS gyroscope is used for simulation. The simulated results of capacitance with this method and the conventional method CMATR1X are 1.5283pF and 1.5793pF. The relative errors between them and the LCR high precision capacitance measuring device measured result 1.5172pF are 0.73% and 4.09% respectively. It is concluded from the experiment this method can obtain high calculating precision for MEMS comb capacitor.