MEMS压阻式压力传感器梁−膜−三岛膜结构设计与优化

Design and Optimization of a Beam-Membrane−Three−Island Structure of MEMS Piezoresistive Pressure Sensor

传统的压阻式压力传感器虽然灵敏度高但非线性度也高。针对该问题,设计了一种以敏感膜片为梁−膜−三岛结构的新型压阻式压力传感器,通过在敏感膜片上设计3个方岛结构来提高传感器的线性度和抗过载能力;同时,利用敏感膜片上设计的短窄梁结构形成应力集中区,保证压力传感器的高灵敏度。对结构进行仿真分析,建立压力膜尺寸参数与力学性能之间的数学模型,对数学模型参数进行了分析、拟合和求解,最后求解非线性约束条件下的极值,完成尺寸优化,传感器性能得到提升。结果表明:在保证传感器低非线性度的条件下,提高了压力传感器的灵敏度,具有良好的力学性能。

The traditional piezoresistive pressure sensor has high sensitivity but also high nonlinearity.To solve this problem,this paper designs a new piezoresistive pressure sensor with a sensing diaphragm of beammembrane-three-island structure.By designing three square island structures on the sensing diaphragm,the linearity and overload resistance of the sensor are improved.At the same time,the stress concentration zone is formed by the short narrow beam structure designed on the sensitive diaphragm to ensure the high sensitivity of the pressure sensor.The structure is simulated and analyzed,the mathematical model between the size parameters of the pressure film and the mechanical properties is established,and the parameters of the mathematical model are analyzed,fitted and solved.Finally,the extreme values under the nonlinear constraint conditions are solved to complete the size optimization,so that the performance of the sensor is improved.The optimization results show that the sensitivity of the pressure sensor is improved and the mechanical properties are good under the condition of ensuring the low nonlinearity of the sensor.