Two-phase jet impingement cooling for high heat flux wide band-gap devices using multi-scale porous surfaces

In the future, wide band-gap (WBG) devices such as silicon carbide and gallium nitride will be widely used in automotive power electronics due to performance advantages over silicon-based devices. The high heat fluxes dissipated by WBG devices pose extreme cooling challenges that demand the use of advanced thermal management technologies such as two-phase cooling. In this light, we describe the performance of a submerged two-phase jet impingement cooler in combination with porous coated heat spreaders and multi-jet orifices. The cooling performance of four different porous coated structures was evaluated using R-245fa as the coolant at sub-cooling of 5 K. The results show that the boiling performance of a pin-fin heat spreader is the highest followed by that for an open tunnel (OPT), closed tunnel (CLT), and flat heat spreader. Furthermore, the flat heat spreader demonstrated the lowest critical heat flux (CHF), while the pin-fin surface sustained a heat flux of 218 W/cm2 without reaching CHF. The CHF values of the OPT and CLT surfaces were 202 W/cm2 and 194 W/cm2, respectively. The pin-fin heat spreader has the highest two-phase heat transfer coefficient of 97,800 W/m2 K, while the CLT surface has the lowest heat transfer coefficient of 69,300 W/m2 K, both at a heat flux of 165 W/cm2. The variation of the pressure drop of all surfaces is similar for the entire range of heat fluxes tested. The flat heat spreader exhibited the least pressure drop, 1.73 kPa, while the CLT surface had the highest, 2.17 kPa at a heat flux of 79 W/cm2. Based on the two-phase cooling performance and pressure drop, it is concluded that the pin-fin surface is superior.