计及热阻与发射极电感匹配的并联IGBT芯片稳态结温均衡方法

Steady Temperature Equalization Method for the Parallel IGBTs Considering the Thermal Resistance and the Matching Emitter Parasitic Inductance

在大量芯片并联的IGBT器件内部,热阻和发射极寄生电感是决定芯片稳态结温分布的关键参数。因此,合理设计芯片并联支路的热阻和发射极寄生电感,对均衡并联芯片的稳态结温非常重要。为此,该文首先建立两IGBT并联芯片的电热模型,研究并联IGBT芯片动态损耗与结温、发射极寄生电感之间的规律。并通过瞬态电热耦合计算,研究热阻和发射极寄生电感对并联芯片结温分布的影响。在此基础上,提出计及热阻与发射极电感匹配的并联IGBT芯片稳态结温均衡方法,可通过联立方程得到热阻或发射极寄生电感的参考值,从而避免复杂的电热瞬态计算。最后以两IGBT并联芯片为例,给出不同工作频率下并联芯片的稳态结温,表明了该文所提稳态结温均衡方法的有效性。

In the IGBT device with the parallel chips,the thermal resistance and emitter parasitic inductance are the key parameters which determine the steady junction temperature distribution.Therefore,to equalize the steady junction temperature of the parallel chips,it is vital to design the thermal resistance and emitter parasitic inductance reasonably.In this paper,an electrothermal model with two parallel IGBT chips is established to investigate the impacts of the junction temperature and the emitter parasitic inductance on the dynamic losses.Then,the effects of thermal resistance and emitter parasitic inductance on the temperature distribution are further studied by the electrothermal coupling simulation.On this basis,the steady temperature equalization method for the parallel IGBT chips is put forward.The proposed method can obtain the reference values of the thermal resistance or emitter parasitic inductance by solving the equation set rather than the complicated electrothermal calculation.Finally,taking two parallel IGBT chips as an example,the steady junction temperature of the parallel chips at different frequencies is demonstrated,which shows the effectiveness of the method.