硅微电容式加速度计热致封装效应的层合分析

摘要

Due to Structural stress and deformation from thermal mismatch,thermally-induced packaging effect on the performance and reliability of MEMS devices is significant. A laminate model based on reduced stiffness matrix is used for modeling the package of silicon micro-machined accelerometer to describe this effect. Through calculat⁃ing the strain and curvature from thermal mismatch of the package by classical laminate theory,temperature charac⁃teristic of the sensing capacitor is obtained,which is used as the evaluation of thermally-induced packaging effect. Finally,results from comparison of FEM simulation and theoretical model show that laminate model can well de⁃scribe the thermally-induced packaging effect of silicon micro-machined accelerometer,based on which,optimiza⁃tion of the package is also analyzed.%由封装结构热失配引入的应力和结构变形会对MEMS器件性能产生显著影响，即热致封装效应。为描述该效应，一种基于缩减刚度矩阵的层合板模型被用来对硅微电容式加速度计的封装进行了建模。利用经典层合理论，由计算封装热失配引入的应变和曲率得到敏感检测电容的温度特性，以此作为热致封装效应的评估。并结合有限元模拟（FEM）对该理论模型进行了对比和验证。结果表明，层合模型能较好地描述硅微加速度计的热致封装效应，并在此基础上分析了优化措施。