Experiment-based investigation of thermal cross-coupling of chips in high-power IGBT modules

Abstract:
This paper introduces the concept of system-level IGBT thermal resistance, the IGBT thermal resistance matrix and the IGBT junction temperature calculation formula. It further describes an experimental method for investigating the thermal coupling effect between IGBT and diode chips within a high-power IGBT module. The system-level thermal resistance is obtained via a single-chip heating method within a half-bridge, high-power IGBT module. An additional method with dual-chip heating is then subsequently used to verify the effectiveness of the former method. In the end, the junction temperature of IGBT and diode chips with and without thermal coupling is analyzed and compared.