Packaging of Double-Side Cooled SiC Power Modules for Traction Inverters

The Vehicle Technology Office of the US Department of Energy has set aggressive targets for electric drive technologies. For traction inverters, the power density targets are 100 kW/Liter by 2025, 150 kW/L by 2030, and 225 kW/L by 2035. Meeting these targets require significant advances in design and fabrication of the inverter and its components, such as wide bandgap semiconductor devices and power modules.

Over the past 25 years, the Center for Power Electronics Systems at Virginia Tech has developed innovative nanomaterials and assembly technologies for power module packaging.

The research has focused on three strategies:

• (1) double-sided cooling to reduce device junction-to-case thermal resistance and package stray inductances;
• (2) sintered-silver bonding to increase the junction temperature above 200 C; and
• (3) electric-field grading by a nonlinear resistive coating to increase the partial discharge inception voltage of medium-voltage power modules.

In this talk, implementation of the first two strategies for packaging SiC MOSFET modules to meet the 100 kW/L inverter power density will be shared.