压接型IGBT器件单芯片子模组功率循环试验仿真

压接型绝缘栅双极型晶体管(IGBT)器件因具有双面散热、短路失效和易于串联等优点,正逐步应用到柔性直流输电等领域.但其在工作过程中的热学、力学特性与传统焊接式IGBT模块相比有很大差异,故存在不同的长期可靠性问题.基于有限元法建立了压接型IGBT器件单芯片子模组多物理场耦合仿真模型,研究了三种功率循环仿真条件下器件的热学和力学特性,并且在功率循环过程中利用金属弹塑性模型来模拟材料的瞬态特性.仿真结果表明,IGBT芯片发射极表面与发射极钼片相接触的边缘是应力集中区域,芯片发射极表面栅极缺口和四周边角处有明显的塑性变形.同时,将仿真结果与实际失效的IGBT芯片进行了对比,进一步验证了仿真模型的有效性和适用性.

Power Cycling Test Simulation for the Single-Chip Submodule of Press-Pack IGBTs

For the advantages of double-sided heat dissipation,short circuit failure and easy series connection,press-pack insulated gate bipolar transistors (IGBTs) are gradually being applied in the field of flexible DC transmission.However,compared with the traditional welded IGBT module,press-pack IGBTs have great difference in thermal and mechanical characteristics during the working process,resulting in different long-time reliability problems.Based on the finite element method,the multi-physics field coupling simulation model for single-chip submodule of press-pack IGBTs was established.The thermal and mechanical properties of the devices were studied under three power cycling simulation conditions.And during the power cycling process,the metal elastoplasticity model was used to simulate the transient features of the material.The simulation results show that the boundary between the emitter surface of the IGBT chip and the emitter molybdenum plate is the stress concentration region,and the plastic deformation at the gate gap and the surrounding corners of the chip emitter surface is obvious.Meanwhile,the simulation results were compared with the actual failure of the IGBTs chip to verify the effectiveness and applicability of the simulation model.