弹簧式压接IGBT模块内部应力及温度仿真分析

Simulation and Analysis of Internal Stress and Temperature in StakPak Press-pack IGBTs

功率半导体器件的寿命与其内部的热力情况直接相关,而接触热阻严重影响压接式IGBT模块内部的温度分布,因此对于接触热阻的精确模拟尤其重要。本文对弹簧式压接IGBT进行了有限元仿真建模,基于蒙特卡洛方法来模拟接触热阻,详细分析了IGBT芯片表面温度和力的分布,提出了施加在单个芯片上的适当压力。对比了子模组中不同芯片表面的温度和应力大小,分析了多芯片子模组中极易首先发生失效的芯片。本研究结果可为弹簧式压接IGBT模块在实际生产制造和提高寿命方面提供理论参考。

The lifetime of power semiconductor devices is directly correlated with the thermal dynamics within their internals.In press-pack IGBT modules,the thermal distribution is significantly influenced by the thermal contact resistance,therefore,accurate simulation of the thermal contact resistance is particularly important.In this paper,the finite element simulation model of StakPak presspack IGBTs was established,the Monte Carlo method was used to simulate the thermal contact resistance.The distribution of temperature and stress on the surface of IGBT chips were analyzed,an appropriate pressure to be applied to a single chip is proposed.Additionally,the chip that will likely fail first in multi-chip submodule was pointed out.The results provide a theoretical reference for the actual production and manufacturing,as well as the improvement of the lifetime of StakPak press-pack IGBT modules.