Hybrid Vapor Chamber-based Cooling System for Power Electronics

Abstract

A hybrid vapor chamber (wick-lined evaporator and wickless condenser) is fabricated and tested on a custom-made power electronic setup to demonstrate its efficacy in cooling power-semiconductor devices. The cooling method omits some metal-wick structures from the interior of the vapor chamber and replaces them with wickless, surface-energy patterned planar components. The heat sources of the tested setup are two N-Channel Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) of TO-247-3 packaging, which are connected in parallel to achieve higher current capability. These MOSFETs are dated Si-based semiconductor devices with very high conduction resistance, with the purpose to emulate high-power applications on a low-power experimental setup with reduced cost. Furthermore, the two semiconductor devices are switched at high frequency to emulate the modern power electronics' accelerating switching-frequency trend. The experimental setup exemplifies modern power electronics applications; therefore, it can be scaled to other power electronic systems requiring advanced cooling.The thermal-management technique takes advantage of the phase-changing properties of water inside a closed chamber consisting of two opposing flat plates, one serving as an evaporator and the other as a condenser. The condenser's wettability pattern increases the condensation heat transfer coefficient and provides the best method to return liquid to the evaporator. The evaporator plate is a wick-lined surface, with a 500 μm thick copper porous wick that allows the returned condensate to evaporate from the area over the two MOSFETs where heat input -and thus evaporation- is greatest.The current vapor chamber advances our prior work on wickless and wettability-patterned platforms, and it is applied in a power-electronics system, with the potential to improve cooling performance. It demonstrates the adaptability of the design philosophy, which can be tailored to meet special thermal-management demands. The present experimental configuration represents a real-world power electronic implementation and demonstrates the hybrid vapor chamber's potential for specialized cooling applications.