多层薄膜结构中的热应力分析

针对当前无法分析MEMS多层薄膜结构中热应力的现状，通过修正Suhir.E提出的双金属带热应力分布理论，提出了MEMS多层薄膜结构的热应力分布模型，该模型适用于评估MEMS多层结构中热应力分布规律，同时为采取合理措施减小应力提供了理论支持。在温度载荷作用下，多层薄膜结构中将产生正应力、剪应力和剥离应力的作用，应力变化主要集中在界面端处。其中，正应力分布于各层内，随与中心点距离的增大呈指数减小，在端面处急剧减小至最小值；剪应力和剥离应力则主要分布于各层界面上，随与中心点距离的增大呈指数增大，在界面端处达到最大值。最后，开展了由四种材料（玻璃、铬、铜、镍）组成的多层薄膜结构的热力学仿真分析，验证了所建立解析模型的正确性，以及各应力在多层结构中的分布规律。

Thermal Stress Analysis on Multilayer Structure

Aimed at the multilayer structure being unable to parse,the thermodynamics distributing model has been put forward by revising bimetal strip stresses model advanced by Suhir. E,which applies to evaluate the thermal stress distributing rule of MEMS multilayer structure. Under the thermal loading,multilayer structure composed by different material will create normal stress,shearing stress and peeling stress,and the stress variety concentre in the end of interface. Normal stress distributes in each layer,which value presents exponential decrease along with the distance from centre of each layer,and decreases sharply in the end until achieve minimum. Shearing stress and peeling stress main distribute in the interface of each layer,both values present exponential increate along with the distance from centre of bonded pair,and increase sharply in the end until achieve maximum. Then,the thermody?namic simulation has been analyzed on multilayer structure composed by four material such as glass,chromium,cu?prum and nickel,which result validate the analytic model and the stress distributing in multilayer structure.