Experimental analysis of thin vapor chamber with composite wick structure under different cooling conditions

In this work, two types of thin vapor chambers, namely, copper foam vapor chamber (CFVC) and copper mesh vapor chamber (CMVC), are developed to enhance the thermal performance of vapor chambers for cooling high heat flux electronic devices. The evaporator wick is a composite wick of sintered copper powder-mesh with multi-artery structures made of several sintered powder bars on a thin evaporator zone. The condenser wicks for CFVC and CMVC are copper foam wick and 3-layer 200 mesh wick, respectively. A water-cooled testing system is set up to investigate the thermal performance of the vapor chamber. The characteristic parameters, including the temperature distribution, thermal resistance, filling ratio and critical heat flux (CHF) of vapor chambers are studied. The results indicate that the thermal performance of the vapor chamber is significantly affected by the cooling water temperature. At cooling water temperatures of 50 and 30 °C, the CHF of the CFVC can reach 180 W/cm2, which is increased by 100–200% compared to that of the CMVC. The CFVC exhibits a better heat transfer performance and adaptability to the cooling water temperature, given that the copper foam wick has a larger capillary performance parameter and a smaller contact thermal resistance.