Abstract
A sub-channels-inserted porous evaporator is proposed as a heat sink for future power electronic devices with a heat load exceeding 300 W/cm2. The porous medium is made by sintering copper particles of micrometer size in diameter and has several sub-channels to enhance discharge of generated vapor outside the porous medium. This porous heat sink is attached to the backside of a heating chip and removes the heat by evaporating a cooling liquid passing through the porous medium against the heat flow. In order to prove the validity of the sub-channels, the heat transfer characteristics of this porous heat sink are evaluated experimentally. The result shows that the heat transfer performance of a sintered-copper particles porous medium with sub-channels enables the removal of much higher heat flux under a lower flow rate of cooling water and a lower wall superheat conditions than those of a normal porous heat sink. The removal heat flux, 810 W/cm2, is 1.8 times higher than that of a normal porous heat sink at a wall superheat of 50 K. Furthermore, it is clarified that even with a heat flux up to 810 W/cm2, it is possible to sufficiently cool the SiC-based chip in practical use.
