Analytical and Experimental Investigation on A Dynamic Thermo-Sensitive Electrical Parameter With Maximum dIC/dt During Turn-off for High Power Trench Gate/Field-Stop IGBT Modules

In this paper, a dynamic thermo-sensitive electrical parameter (DTSEP) for extracting the junction temperature of the trench gate/field-stop insulated gate bipolar transistor (IGBT) modules by using the maximum collector current falling rate is proposed. First, a theoretical model of the transient collector current during turn-off process is developed in terms of the behavior characteristics of the inside storage carriers. Then, the inherent linear relationship between the maximum collector current falling rate dIC/dt and junction temperature Tjis demonstrated and investigated. Fortunately, benefitting from the presence of the intrinsic parasitic inductance LeEbetween the Kelvin and power emitters of IGBT modules, the maximum dIC/dt can be easily measured to validate the theoretical analysis. Consequently, the maximum dIC/dt during turn-off process is a promising DTSEP for IGBT module junction temperature estimation. Moreover, the physical device parameters that affect the temperature sensitivity of the maximum dIC/dt are also discussed with the derived transient collector current falling model.