ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
HYBRID WICK VAPOR CHAMBER THERMAL PERFORMANCE EVALUATION FOR HIGH HEAT FLUX APPLICATION BY AIR COOLING
Abstract
The growing electrification of transportation systems
and clean-energy-production technologies is dramatically
increasing the waste heat load that must be dissipated from
high-density power electronics. Air cooling, considering overall heat exchange simplicity, remains a proven and reliable
approach for which robust heat transfer systems are readily and
accurately designed. However, the primary limitations for air
cooling are the relatively low heat transfer coefficients that are achievable, ~25-250 W/m2-K, and heat fluxes that may be cooled, ~0.1-10 W/cm2. Thus, transformative embedded heat spreading technologies must be developed in next-generation systems to enable air cooling of power semiconductors with heat fluxes exceeding 500 W/cm2 over large hotspot areas up to 1 cm2. A vapor chamber heat spreader, or thermal ground plane (TGP), offers a potentially viable solution if implemented as a heat sink base. Such advanced vapor chamber technology is being investigated as one possibility in handling the high heat fluxes of next-generation wide band-gap power devices, while exploiting their high temperature capability plus the simplicity of an air-cooled system. In this study, a 10 cm × 10 cm monoporous/bi-porous, i.e. hybrid, wick vapor chamber is designed and tested in combination with a straight pin fin heat sink under air jet impingement and a 1 cm2 size heat source. Per the experimental results, the customized hybrid wick TGP exhibits ~28% lower thermal resistance compared with a traditional commercial TGP, and the capillary limit heat flux (CLHF) is measured as 450 W/cm2 under the above-mentioned air-cooled
conditions. Technical challenges in extending this CLHF value
and TGP integration into packaged electronics are described.