Effects of parasitic parameters on electromagnetic interference of power electronic modules

Abstract

Electromagnetic interference (EMI) is a concern for modern day wide bandgap (WBG) power electronic modules due to the increasing demand for fast and high frequency switching. In this paper, EMI issues due to parasitic ringing at turn-on and turn-off of silicon carbide (SiC) power devices are investigated. To illustrate the need for parasitic optimization to reduce EMI at turn-on and turn-off, wire bonded and wire bondless power modules with a single switching position consisting of two SiC power devices connected in parallel are considered. The wire bondless power modules exhibit lower parasitic inductances compared to wire bonded power modules. As such, the turn-on and turn-off ringing is significantly reduced for the wire bondless power module yielding reduced radiated EMI. To measure the conducted EMI, wire bonded and wire bondless power modules are fabricated and characterized. The wire bondless power modules are shown to have better electromagnetic compatibility at both radiated and conducted frequency range.