面向动态压力测量的微型压力传感器敏感结构

Structural Analysis of Micromachined Piezoresistive Pressure Sensors for Dynamic Pressure Measurements

围绕微型压力传感器的动态性能对压力敏感结构设计进行了研究。结合有限元分析,掌握了压阻式微型压力传感器的膜片形状、膜厚、膜片平面尺寸对于固有频率、灵敏度的影响规律,明确了固有频率、灵敏度与敏感结构形状尺寸间的关系。结合研发实例,利用时域暂态有限元分析,研究了不同厚度的正方形敏感膜片对于正弦、阶跃压力载荷的动态响应情况。研究表明,较小的敏感膜片平面尺寸、较大的膜片厚度有利于获得高的固有频率,从而得到较宽的工作频带、较快的响应速度。

The structural design of the membrane with piezoresistors of micromachined pressure sensors was studied with the special consideration of its dynamic performance. With FEA simulation, the structural analysis of micromachined piezoresistive pressure sensors for dynamic pressure measurements was carried out. The influences of the membrane shape, thickness, shape and dimension on the natural frequency and sensitivity were studied. With the transient FEA, the dynamic responses of the square membrane with different thicknesses under sine pressure loads and step pressure loads were studied. The research indicates that the membrane with smaller plane dimension and thicker thickness is benefit to gain a higher natural frequency, the wider frequency bandwidth and the higher response speed.