Ultra-compact SiC power module with sintered DCB on microchannel cooler

Abstract:
The intentions of the More Electrical Aircraft (MEA) concept are weight reduction and higher efficiency. The main topic here is the application of electrical systems instead of conventional hydraulical, pneumatical and mechanical systems. Some of these systems require a liquid cooling, which results in additional weight for pipes and heat exchanger. The total weight of cooling loop can be optimized by increasing the absolute inlet temperature and the difference between inlet and outlet temperature. Subsequently, the power modules must be designed for a higher case temperature by reduction of power loss and thermal resistance. The main impact on the overall thermal resistance has the thermal interface material, which can be avoided by sintering of the ceramic substrate directly on the heatsink. A further improvement is possible by planar interconnection technologies instead of conventional aluminium bonds and the use of high performance liquid coolers such as the micro-channel technology. Reduction of power loss can be achieved by using SiC-MOSFETs instead of IGBTs with freewheeling diodes. This paper presents an ultra-compact B6C power module consisting of a high performance micro-channel liquid cooler with integrated DCB substrate and sintered SiC-MOSFETs with planar interconnection technology SiPLIT(r). This power module offers a high power density due to low thermal resistance and reduced power loss.