采用微机电系统(MEMS)牺牲层技术制作的压力传感器具有芯片尺寸小,灵敏度高的优势,但同时也带来了提高过载能力的难题。为此,利用有限元法,对牺牲层结构压阻式压力传感器弹性膜片的应力分布进行了静态线性分析和非线性接触分析。通过这两种分析方法的结合,准确的模拟出过载状态下传感器的应力分布。在此基础上给出了压力传感器的一种结构设计方法,从而可使这种压力传感器过载保护能力提高180%~220%。
In microelectromechanical systems(MEMS),the pressure sensor made by the sacrificial layer technique has advantages such as small chip size and high sensitivity,which nevertheless results in the difficulty to increase the overload ability.Thus,the stress distribution on the elastic thin film of the sacrificial layer piezoresistive pressure sensor was simulated and analyzed by the finite-element analysis using both static linear and nonlinear contact methods.Through the combination of these two methods,the stress distribution was simulated accurately under the state of overload.Based on the analysis results,a structural design method was proposed,which can increase the overload ability to about 180%~220%.