Research on Quasi-on-line Extraction Method of Junction-case Thermal Resistance of IGBT Module

Solder failure is responsible for a significant proportion of overall faults of insulated gate bipolar transistor (IGBT) module. Therefore, An effective method for monitoring the health of the solder layer is an important guarantee for the reliable operation of the system. The measurement method of IGBT steady-state junction-case thermal resistance based on high-current saturation voltage drop proposed in this paper, which can provide guidance for the health monitoring and failure assessment of the solder layer of IGBT modules. Firstly, based on the electrothermal coupling characteristics of the IGBT module, a calculation model for the steady-state junction-case thermal resistance of the IGBT is established. This model does not need to obtain the junction temperature and can realize the quasi-on-line measurement of the steady-state junction-case thermal resistance of the IGBT module. Then, the IGBT module electrothermal parameter measurement experimental platform and the steady-state junction-case thermal resistance measurement platform are established, the undetermined parameters in the IGBT steady-state junction-case thermal resistance calculation model are quantitatively analyzed, and the measurement steps of the steady-state junction-case thermal resistance are introduced. Lastly, the failure simulation of the solder layer of the IGBT module is carried out, and the validity of the proposed steady-state junction-case thermal resistance measurement method is verified based on the experimental platform.