力平衡式三轴微加速度计的设计与分析  

Design and Analysis of a Three-Axis Micro Accelerometer with Force Balance Feedback

作　　者：潘武[1] 张昱[1] 

机构地区：[1]重庆邮电大学微光机电系统研究所,重庆400065

出　　处：《纳米技术与精密工程》2006年第2期141-145,共5页Nanotechnology and Precision Engineering

基　　金：国家高技术研究发展计划("863"计划)重大项目(2005AA123730)重庆市教委科学技术项目(020508)

摘　　要：设计了一种具有单一检测质量的力平衡式三轴微加速度计．采用硅-硅键合工艺形成作为单一检测质量块的硅片组合,利用全差分电容检测法实现对加速度三轴分量的检测．通过提高检测质量的重心,有效增加了X、Y 轴的灵敏度．利用ANSYS仿真软件对该微加速度计进行了模态及静力学分析,提出了优化设计参数．3个检测模态 (1阶、2阶和3阶模态)的频率分别为1．329 kHz、1．345 kHz 和2．174 kHz．通过优化设计,提高了3阶模态和4阶模态的频率差距,降低了其他高阶模态的干扰．在100g(g为重力加速度)的Z向加速度作用下,悬臂梁所受的最大应力为46 MPa,小于单晶硅的弯曲极限值70-200 MPa．静力学分析表明,加速度计的悬臂梁结构参数能够满足加速度计的力学性能要求．A three-axis micro accelerometer with a single proof mass and force balance feedback is designed in this paper. The silicon module as the single proof mass is made by silicon-silicon bonding technology. The three-axis components of acceleration are measured by full differential capacitive detecting method. The sensitivities in X and Y axes are improved by lifting the mass center of detecting mass module. The states and modes of micro accelerometer are analyzed by the finite element analysis （FEA） software ANYS, Sand the optimized structure parameters are put forward. The frequencies of the first, the second and the third order modes are 1. 329 kHz, 1. 345 kHz and 2. 174 kHz respectively. The frequency difference between the third and the fourth order modes is improved by optimized design to reduce the interferences of other high order modes. When the acceleration in Z axis is 100g （g is the acceleration of gravity）, the biggest stress in the cantilever beam is 46 MPa which is smaller than flexural limit of single crystal silicon （70-200 MPa）. The finite element analysis results show that the structure parameters can meet the requirements of the micro accelerometer.

关 键 词：三轴微加速度计 差分电容 灵敏度 阳极键合 模态分析 

分 类 号：TH824.4[机械工程—仪器科学与技术]