Switch Cell Design for Novel High-frequency Press-pack SiC FET Modules

This paper presents a novel high-frequency press-pack (HFPP) SiC FET module for broad medium-voltage (MV) high-power areas, such as grid distribution and protection and high-speed drives. By incorporating a significant number of low-specific-resistance SiC FET dies in a single package, the SiC FET modules are expected to achieve at least 5× lower conduction losses and 10× faster switching frequency compared to Si press-pack (PP) IGBTs and maintain a short-circuit failure mode (SCFM). As an essential part of the HFPP SiC module development, this work proposes a novel package-level switch-cell building block (SCBB) concept and rotated stacking structure for low power-loop inductance in a variety of multilevel topologies, along with the switch cell's design and packaging details. The latter includes double-sided sintering of SiC dies and a proposed four-leg monolithic spring for pressure generation. Simulations, fabrication, and partial experimental validation are exhibited.