微机电系统中凸台-弹性膜结构的力学建模与仿真

Mechanical modeling of mesa-diaphragm structures in microelectromechanical systems

为了测试和评定微构件的力学特性,建立了凸台弹性膜结构的力学模型。将凸台弹性膜结构化简为中心带有凸台的无限长薄板条结构,利用板壳理论得出了凸台的弹性模量、厚度和横截面积对弹性膜表面应力分布影响的解析计算公式,并通过有限元分析对计算结果进行仿真验证。理论分析和仿真结果吻合。凸台弹性膜复合结构的等效弯曲刚度与凸台的弹性模量和厚度有关,当凸台的弹性模量和厚度增加时,凸台弹性膜复合结构的等效弯曲刚度增大,可以通过增加凸台的弹性模量和厚度来提高凸台弹性膜结构的强度。该研究为凸台弹性膜结构的优化设计和应用提供了计算方法和设计依据。

A mechanical model of mesa-diaphragm structures was used to test the mechanical characteristics of microstructures. The diaphragm was approximated by an infinitely long thin plate embossed in the center. A formula deduced using the theory of plates and shells related the mesa elastic modulus, thickness and cross-sectional area to the surface stress distribution at the diaphragm. The formula was confirmed by finite-element simulations. The results show that the equivalent flexural rigidity of the mesa-diaphragm structure increases with increasing elastic modulus and mesa thickness. Therefore, the strength of the compound structure can be increased by increasing the elastic modulus and mesa thickness. The analytical model provides a method to optimize the design of mesa-diaphragm structures.