DBC-based Embedded Micro-channel Cooler for the High-Power Density Power Module

Thermal limitation is a critical constraint on the power density of the power modules. The conventional cold-plate solutions suffer from high thermal resistance from junction to coolant due to the interface between the module and cold-plate. The high interfacial resistance and pressure drop hamper the performance scaling. An optimized thermal solution that integrates the cooler into the power module is desired to satisfy the cooling need for the high power density modules. We have developed a microchannel cooler embedded into the direct bonded copper (DBC) substrate for the double-sided power module. A liquid-cooled manifold microchannel cooler is integrated into the copper layer of the DBC substrate, eliminating the interfacial resistance. The multi-layer manifold design is implemented in this embedded cooler for low pressure drop and enhanced liquid delivery. The double-sided DBC module with an embedded cooler demonstrated a low junction to coolant thermal resistance of 0.09 cm2K/W, enabling the operation of the SiC chip with an area of 31 mm2 at the maximum dissipated power of 378.9 W and leading to the maximum chip drain-source current of 156.6 A. This work illustrates a milestone in evolving from the conventional cold-plate solution to a high-performance embedded cooler. We demonstrate a promising solution for significantly improving the power density of the power module. A novel and radical cooling solution, such as a two-phase cooler, will be integrated into the power module for future performance optimization.