Thermal modeling of wire-bonded power modules considering non-uniform temperature and electric current interactions

Abstract

To assess power devices' reliability, it is crucial to have a relatively accurate thermal approach which provides valid temperature estimates. In this paper, a commercial Si IGBT and SiC MOSFET power modules are investigated. Also, the electric current-induced effects on bond wires and the correlation between the non-uniform temperature distribution and electrical conductivity of the sensitive constituent materials are studied. A more realistic active area of the die is defined by excluding inactive regions, i.e., the gate area, gate runners, and termination ring. Also, the electric current distribution among parallel bond wires attached to the dies' metalization pads is investigated. A comparison between an approach which includes all the above aspects with a conventional one where a thermal power with the same total value, but unifrom, is injected into the semiconductor dies is made, While an acceptable error is found for Si IGBTs, a very significant difference is observed in SiC MOSFETs.