Fault Analysis of a Half Bridge Power Module

As for the phenomenon of explosion failure of IGBT power module in the short-circuit current test, a new failure model of multi-chip module caused by the failure of reverse recovery anti-parallel diode chip is proposed. Based on the proposed model, various influence factors from the aspects of circuit layout and device mechanism are analyzed and discussed. By investigating the position and fault waveform of the internal chip and anti-parallel diode of IGBT power module, as well as the physical analysis after power module unraveling, we can conclude that the uneven current density of the anti-parallel diode chip that leads to the dynamic avalanche breakdown is the main reason of the explosion failure of the IGBT power module. Finally, suggestions for improving the firmness of the IGBT power module are given, which is of guiding significance to the design and manufacture of IGBT.