Analysis on Ultra-Fast Switching of SiC MOSFETs for Megahertz Applications Enabled by 3D Package and Embedded Components

Abstract

Among advantages of Wide bandgap (WBG) power devices, fast switching characteristic has attracted tremendous interests for high frequency power conversion systems. High frequency operation enables size reductions on magnetic components in converters, which will increase power density of entire systems. However, commutation inductance distributed in power conversion systems poses limitations for switching speed improvement. Thus, innovative high density power module solutions are required to address parasitic inductance reduction. In this paper, the impact of parasitic inductance distributed in power module, including parasitics at drain, source and gate loop, was analyzed by simulations and experiments. A previously proposed Three-dimensional (3D) power module solution for 1.2kV SiC MOSFETs in half bridge is analyzed. The 3D solution enables ultra-low parasitic inductance, 1.3nH, in the half bridge power module. Additionally, embedded component is employed in the 3D package SiC power module. Simulations and tests proves that the 3D solution with embedded components facilitates ultrafast switching speed for 1.2kV SiC MOSFETs, 12ns turn-on and 8ns turn-off, with limited ringing even at >700Vdc. The proposed SiC half bridge module in 3D package with embedded components provides solutions for Megahertz high density power conversion systems.