Evaluation of Heat Spreading Technologies Within Double-Side-Cooled Power Modules

The packaging used for power modules can be the dominant thermal resistance, greater than the convective thermal resistance. The use of advanced heat spreaders within the power module can enable improved heat dissipation, resulting in lower package conduction resistance. Advanced heat spreading is even more beneficial for silicon carbide (SiC) devices given their smaller size and higher heat fluxes. This paper evaluated the use of vapor chambers, graphite-based, and copper (Cu)-diamond heat spreader technologies as possible thermal management solutions for SiC double-side-cooled power modules. Experimental measurements with a vapor chamber were conducted and were consistent with what is reported in the literature, demonstrating that current vapor chamber technology is not suited for automotive power electronics applications. Thermal modeling of advanced module concepts that integrate heat spreaders within the power module predict enhancements as compared with the baseline module without a heat spreader. Cudiamond heat spreaders are predicted to be more effective at reducing the module's thermal resistance as compared with graphite-based heat spreaders. Finally, transient thermal models were developed and used to predict the temperature response for the advanced modules for a representative drive cycle.