Jet Impingement Cooling of an Inverter Module in the Harsh Environment of a Hybrid Vehicle

This paper presents a study of liquid jet impingement cooling technique and its system level implementation for thermal management of an inverter module in a hybrid vehicle. Clusters of anti-freeze liquid jet array impinge on the base plate of a 450V (DC Link voltage)/400A (RMS current) module, made by Semikron, Inc. In the harsh environment of an automobile, the ambient temperature of the coolant is 105°C, and the maximum allowable flow rate and pressure drop are 2.5GPM and 1.6bar respectively. The impingement cooling technique demonstrates 1623 Watts of heat dissipation for 20°C device temperature rise above ambient. This translates to a chip level dissipation power density of 56W/cm², approximately 1.8X improvement over forced convection liquid cooling in the state-of-the-art pin fin cold plate. At the highest power, the less than 3°C temperature variation among the twelve IGBT measurements indicates a high degree of reliability in module operation. The efficient phase change heat transfer mechanism sets in at local base plate temperatures between 109–111°C, which accounts for more than 10% of the total heat dissipation at 1600W level.