10 kV SiC Power Module Packaging

Abstract:
High-voltage SiC devices offer an attractive combination of fast switching and low losses, giving application users unprecedented levels of flexibility in choice of topology and control strategy for medium- and high-voltage power conversion. However, the realisation of power modules that are optimised for the high electric fields, whilst maintaining compact commutation loops and effective thermal management, presents significant challenges to accepted design norms. This paper describes the design, fabrication and characterisation of a high-density, 10 kV, 60 A, wire-bond-less, planar SiC half-bridge module. Key design considerations include: the mitigation of high electric fields in the substrates, interconnects and lead-out connections; suppression of switching voltage overshoot and common-mode interference; high-performance thermal management. Details of the fabrication of a planar module, employing stacked substrates, embedded decoupling capacitors and integrated thermal management are presented. The resulting module has power- and gate-loop inductances of 4.4 nH and 3.8 nH and a power density of 18.1 W/mm(Exp 3). Results are presented detailing the electrical and thermal performance of an initial prototype.