Abstract: Aiming at the reliability problem of high-power IGBT modules under short circuit extreme operating

conditions，the power terminals imbalanced current of IGBT modules and the resulting dynamic junction

temperature change were comprehensively analyzed. Firstly，the current sharing characteristics of parallel terminals

of an Infineon 3 300 V/1 500 V IGBT module under short circuit was tested by experiments，and the power loss of

each terminal was obtained. Secondly，the thermal model of the IGBT module was built by finite element method，

and the effect of imbalanced current on the transient thermal characteristics of IGBT chips was further studied. The

results show that the difference of terminals current under short circuit can reach 1 500 A，thus causes the junction

temperature of IGBT to differ by about 11 °C，which increases the risk of transient thermal breakdown of IGBT. The

conclusions could provide guidance for optimal design of IGBT modules.

      Key words: IGBT module；short circuit；parallel current sharing；junction temperature