Thermal measurement and analysis of packaged SiC MOSFETs

Abstract

This paper reports an approach for transient thermal resistance measurement and thermal analysis of packaged SiC MOSFETs. A relationship of gate-source voltage (VGS) and temperature of a SiC MOSFET measured using constant current pulses of 2A that have width of 200μs is employed to measure junction temperature. The transient thermal resistance of the packaged SiC MOSFET is measured with constant current injection of 2A in heating condition. A modified thermal resistance analysis by an induced transient (TRAIT) method is introduced. The measured transient thermal resistance is characterized with a discrete time constant spectrum, and analysed using structure functions based on a Cauer equivalent thermal model. The partial thermal resistances of the packaged SiC MOSFET were extracted and compared to the results from the thermal model based on finite difference method (FDM), and comparison shows good agreement between both results.