改进IGBT动态模型与电-热-力多物理场耦合失效分析

Improved IGBT dynamic model and electro-thermal-force multiphysics coupling failure analysis

绝缘栅型双极型晶体管(IGBT)失效会对整流或逆变系统产生严重影响, IGBT应用场合不同导致其焊料层失效形式存在较大差异,因此有必要研究IGBT焊料层老化失效规律。首先利用改进的IGBT动态模型搭建三相整流电路并对其电路功耗误差进行修正;其次构建IGBT三维有限元模型,并分析其在电-热-力多物理场耦合下芯片温度和焊料层应力分布规律;最后利用随机生成的焊料层缺陷来探究空洞、裂纹等对焊料层失效的影响,得出焊料层老化失效规律。仿真结果表明,焊料层缺陷面积的比例高于15%时,焊料层空洞、裂纹及脱落对芯片结温及焊料层应力影响显著,其中,脱落和裂纹对焊料层应力影响更大。

Failure of insulated gate bipolar transistors(IGBTs)can make a serious impact on the entire rectification or inverter system.IGBTs are used in different practical applications,causes a large difference in the form of failure of its solder layer.Therefore,it is necessary to study the aging failure law of IGBT solder layer.Firstly,the improved IGBT dynamic model is used to build a three-phase rectifier circuit and correct its circuit power consumption error.Then constructing three-dimensional finite element model of IGBT and analyzing its chip temperature and solder layer stress distribution under electro-thermal-force multiphysics coupling.Finally,the randomly generated solder layer defects are used to investigate the effects of voids,cracks,etc.On solder layer failure,and the aging failure mechanism of the solder layer is obtained.The simulation results show that after the solder layer defect area ratio is higher than 15%,solder layer voids,cracks and shedding have a significant effect on chip junction temperature and solder layer stress.Among them,shedding and cracks have a greater influence on the stress of the solder layer.