非硅MEMS惯性开关可靠性研究  

Reliability Study of Non-Silicon MEMS Inertia Switches

作　　者：刘加凯[1] 齐杏林[1] 

机构地区：[1]军械工程学院弹药工程系,石家庄050003

出　　处：《微纳电子技术》2012年第12期802-806,共5页Micronanoelectronic Technology

摘　　要：非硅MEMS惯性开关具有体积小、成本低、可批量生产以及强度和导电性能较好的优点,但其可靠性问题制约了其应用领域。通过开展非硅MEMS惯性开关的可靠性实验(包括温度循环实验和随机振动实验),找出其主要失效模式为分层。通过对失效部位进行分析,并利用有限元方法分析器件上的应力分布,研究了相应的失效机理。研究结果表明:引发惯性开关分层失效的主要原因是层间产生疲劳效应,温度循环应力会使惯性开关各层间由于热膨胀系数失配而产生疲劳,而振动应力则直接加载在惯性开关上而使其产生疲劳;惯性开关中铬层与铜层之间最易发生失效,而分析表明该层间界面处热应力最大;经历温度循环实验和振动实验的惯性开关相较只经历一种实验的样本更容易失效,进一步说明了温度循环应力会使开关层间发生疲劳,而振动应力则会引起应力集中而加速分层失效。The non-silicon MEMS inertia switch possesses the advantages of small volume, low cost, lower contact resistance and batch production capability. However, the reliability issues of MEMS switches are always the significant restriction to the extension of their applications. Ther- mal cycling and random vibration tests of the stability for the non-silicon MEMS switch were per- formed, and the main failure mode was found to be the delamination of the multi-layer metal. The failure mechanism was studied through the analysis of the failure zone and stress distribution of the device with the finite element method. The research results show that the failure mechanism was contributed to the material fatigue in the thermal cycling test due to thermal mismatch. In addition, the vibration stress directly applied to the inertia switch generates the fatigue and de- lamination occurs. The delamination most likely happens between the Cr layer and Cu layer be- cause of the existence of the strongest thermal stress between them. The inertia switch tested by the temperature cycle and vibration experiment compared with that tested by only one experiment is easier to failure, which further shows that the temperature cycle stress can make the fatigue oc- cur between the switch layers, and the vibration stress will cause the stress concentration and ac- celerate the stratified failure.

关 键 词：非硅MEMS惯性开关 可靠性 温度循环 随机振动 分层失效 疲劳 

分 类 号：TH703[机械工程—仪器科学与技术]