基于多物理场仿真的平面封装SiC模块长寿命设计  

Reliability Design for Planar Multi-chip SiC Modules Based on Electro-thermo-mechanical Simulation

作　　者：能立强 梅云辉[1] 陆国权[1] NENG Liqiang;MEI Yunhui;LU Guoquan(School of Materials Science and Engineering,Tianjin University,Nankai District,Tianjin 300350,China)

机构地区：[1]天津大学材料科学与工程学院,天津市南开区300350

出　　处：《中国电机工程学报》2020年第6期1769-1774,共6页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51877147,U1966212);国家重点研发计划项目(2018YFB0104502)。

摘　　要：碳化硅(silicon carbide,SiC)功率模块热流密度剧增,将严重影响SiC模块长期工作的可靠性。这是因为多种封装材料与芯片之间热膨胀系数差异显著,以及高热流密度带来的高温变梯度会产生显著热应力和应变。尤其对于平面型封装结构的SiC模块来说,其热失配应力效应更加显著,极易造成连接层的疲劳失效。因此,亟需仿真并优化SiC模块的应力和应变分布,提高其工作寿命。该文运用多物理场耦合的有限元仿真方法,首先研究烧结银层和缓冲层对平面封装SiC模块中多层烧结银互连温度和应力的影响规律;通过响应面优化方法同时对多个变量进行优化设计,实现降低芯片和烧结银互连的温度和应力;根据修正的Coffin-Manson方程实现对烧结银平面封装SiC模块的疲劳寿命预测,验证了封装结构应力优化可有效延长SiC模块寿命的设想。The thermal flux of SiC module increases sharply,which will seriously affect the long-term working reliability.The significant differences in thermal expansion coefficient between a variety of packaging materials and chips,as well as the high temperature gradient caused by high heat flux produce significant thermal stress and strain.Especially for the planar Si C modules,manifest electro-thermomechanical stress and strain for interconnections and devices,leading to fatigue failure of SiC devices.Therefore,it should be quite critical to optimize the electro-thermo-mechanical stresses to enhance the reliability of the planar SiC modules.In this paper,the effects of the sintered silver interconnection and buffer layerson the temperature and stress distribution of the sintered attachment in a planar SiC module were studied using the finite element simulation method.The response surface optimization method was used to optimize the design of multiple variables,so as to reduce the temperature and stress and improve the reliability of Si C module.Finally,the modified Coffin-Manson equation was used to predict the fatigue life of the planar SiC module.

关 键 词：SiC模块 平面封装 热-机械应力 寿命预测 

分 类 号：TN386[电子电信—物理电子学]