热、振及热振耦合作用下IGBT模块失效分析

Failure analysis of IGBT modules under thermal,vibration and thermal vibration coupling effects

针对功率器件IGBT模块在多场载荷作用下的焊层失效问题,设计并构建了IGBT模型,基于有限元仿真软件对IGBT模块进行热循环、随机振动以及热振耦合试验,并对三种载荷条件下失效位置的分布规律以及失效模式进行对比分析。结果表明,在热循环载荷条件下,应力集中在DBC焊接层下表面中心位置,最大应力值为226.84 MPa;在随机振动载荷条件下,应力集中在DBC焊接层下表面周边边角位置,最大应力值约为0.0023 MPa;在热振耦合条件下,应力集中在DBC焊接层上表面靠近中心及周边边角位置,最大应力值为377 MPa。热振耦合条件下的焊料层力学行为表现有所变化。研究结果对多种不同载荷下功率器件IGBT模块的响应特性分析提供参考,同时为模块结构的设计提供理论依据。

To address the failure problem of IGBT modules for power devices under multiple field loads,the model of IGBT module was designed and constructed.Finite element simulation software was used to conduct thermal cycling,random vibration,and thermal vibration coupling tests on the IGBT modules.The distribution patterns and failure modes of three module failure positions were compared and analyzed under three different load conditions.The results show that the maximum stress is 226.84 MPa under thermal cycling load,which appears in the center of the lower surface of the DBC welding layer.In the random vibration load,the maximum stress value is 0.0023 MPa,which occurs at the edges and corners of the lower surface of the DBC welding layer.In the thermal vibration coupling load,the maximum stress value is 377 MPa,which occurs on the surface of the DBC welding layer near the center and surrounding corners.Under the condition of thermal vibration coupling,the mechanical behavior of the module welding layer changes,and the average stress of each structure of the module increases by 50.11%.The research results provide a reference for the analysis of the response characteristics of power device IGBT modules under various loads,and also provide a theoretical basis for the design of module structures.