Si-IGBT and SiC-MOSFET hybrid switch-based 1.7 kV half-bridge power module

Abstract

• Design guidelines, fabrication process, and evaluation of a 1.7-kV and 300-A multi-chip half bridge power module using the novel Si-IGBT and SiC-MOSFET hybrid switch in each switch position. • The module achieves its maximum DC current rating with a 6:1 current ratio of Si to SiC. • A novel custom-designed TPG-encapsulated metal base plate is proposed. • Silver clips for top-side interconnect in the module, facilitating a wire bond-less interconnection, high reliability, and low power loop inductance. • High thermal dissipation capability while maintaining a near-isolated thermal path for the SiC MOSFET to operate at a higher temperature than the Si-IGBT. This paper informs the design guidelines, fabrication process, and evaluation of a 1.7-kV and 300-A multi-chip half bridge power module using the novel Si-IGBT and SiC-MOSFET hybrid switch in each switch position. The module achieves its maximum DC current rating with a 6:1 current ratio of Si to SiC. This high current ratio yields significant cost savings compared to an all-SiC power module. The module employs high-reliability silver clips, which replaces conventional wire bonds for top-side interconnection, to partly enable a low power loop inductance of 12.38 nH. A novel thermal pyrolytic graphite-encapsulated metal baseplate is key to reducing the thermal coupling among the adjacent Si and SiC die, enabling higher junction temperature for SiC die relative to the Si die.