固支结构对压阻式压力传感器的输出影响研究

Study on Influence of Fixed Support Structure on Piezoresistive Pressure Sensor Output

针对MEMS压阻式压力传感器微型化发展过程中精度难以保证的问题,通过有限元仿真分析方法,研究固支结构、封装约束方法等变量对压力传感器输出的影响。结果表明,固支结构的引入会导致压敏电阻所处路径出现24.93%的应力偏差,不同封装方法会使路径上产生0.54%~2.42%的应力偏差。当固支结构宽度与压力敏感薄膜膜厚的比例大于3∶1时,压敏电阻所处位置应力积分均值稳定。结果表明,固支结构的约束方法、结构宽度均会对压力传感器的输出产生重要影响,合理设计固定约束结构可为压力传感器的微型化高性能设计提供保障。

In view of the difficulty in ensuring the accuracy of MEMS piezoresistive pressure sensor in the process of miniaturization,the influence of the fixed support structure,packaging constraint method and other variables on the output of the pressure sensor was studied by finite element simulation.The results show that the stress deviation of the path of the varistor is 24.93%due to the introduction of the fixed support structure,and different packaging methods can produce 0.54%~2.42%stress deviation on the path.When the ratio between the width of the supported structure and the thickness of the pressure-sensitive film is greater than 3∶1,the mean value of the integral stress at the position of the pressure-sensitive resistor is stable.The above results show that the constraint method and structure width of the fixed structure have an important influence on the output of the pressure sensor,and the reasonable design of the fixed constraint structure can provide a guarantee for the miniaturization and high performance design of the pressure sensor.