Investigation on diode surge forward current ruggedness of Si and SiC power modules

This paper investigates the behavior of selected Si-PiN and SiC (BD-MOS & SBD) FWD in multichip power modules during current surge event conditions. Surges can occur in high power converters used for motor drives and grid connected systems. A novel testbench and testing procedure is introduced which allows fairly rapid type-test characterization of modules without the need to perform manual-intensive module characterization after each test. Based on the limited tests done so far, it can be seen that Si PiN diodes still retain an advantage as far as surge current limitation is concerned, followed by Mosfet body diodes in SiC with Schottky diodes in SiC at the last place. Experimental and manufacturer data are here combined into a transient thermal model which helps understand the destruction mechanisms.