Direct Liquid Cooling of Power Electronics Devices

Abstract:
Power electronic devices are generating heat losses up to several hundred W/cm². The heat is generated by the active components (IGBT’s, mosfets and diodes). Chip shrinking is causing a steady increase of heat to be dissipated per unit area. Also, increasing ambient temperatures (e.g. in automotive applications) are limiting the use of conventional cooling systems (i.e. conduction to convective air heat dissipation). The thermal resistance of conventional air cooled standard modules is characterized by many interfaces with poor thermal conductivity. To eliminate these main barriers requires a new approach. The main barriers are identified and a solution to eliminate these barriers proposed. Direct liquid cooling of base plates has given the best results. Stacked liquidcooled modules introduce the possibility of switching high power in a minimum volume.