封装内气体对电热驱动MEMS性能影响的有限元分析

摘要

研究了封装内的气体对电热驱动型MEMS的性能的影响.采用有限元分析方法,得出了封装内充入不同组分的氮气和氦气混合气体时MEMS的温度场和驱动位移.分析结果表明,随着封装内混合气体中氦气含量的增加,混合气体的导热系数增加,MEMS机械臂上的温差减小,驱动位移减小.为了提高MEMS性能和保持产品的批量一致性,封装内作为检漏用的氦气的含量在检漏工艺允许范围内越少越好,并且保持含量稳定不变.%The influence of insert packaging gas composition on electrothermal Micro-Electro-Mechanical-System(MEMS)device performance is studied in this paper.With finite element method,both the temperature field and thermal deformation of the MEMS under different composition of mixed insert packaging gas are obtained.The results show that with the increase of helium content in the mixed gas,the thermal conductivity of the mixed gas increases,the temperature difference on the MEMS arm decreases,and the driven displacement decreases.In order to improve the performance of MEMS device and maintain the consistency of the product,the helium which is used for leak detection should be as less as possible within the requirement of lead detection process,and the content of insert packaging gas should be kept stable.