Abstract
This paper presents a circular ultra-thin vapor chamber (UTVC) with a thickness of 1.3 mm for LED lamp thermal management. Superhydrophilic patterned microstructure (SPMS) arrays are fabricated on the upper and bottom covers to replace the traditional wick structure. The heat transfer performance of the ultra-thin vapor chamber was experimentally investigated under different cooling water temperatures in the horizontal orientation. The cooling water temperatures range from 25 to 40 °C, and the input-heat loads range from 5 to 25 W. The results show that for the proposed UTVC with SPMS arrays, the temperatures rise rapidly with increasing input-heat load and then level off after a certain period, with the temperature rise being considerably smaller than that of the ceramic heater. The condenser temperature difference increases with both the input-heat load and the cooling water temperature, and it ranges from 1.2 to 7.3 °C. Both the heater-to-vapor-chamber thermal resistance and the system thermal resistance increase with a higher input-heat load and a lower cooling water temperature. The heater-to-vapor-chamber thermal resistance ranges from 0.80 to 1.34 K/W, and the system thermal resistance ranges from 3.10 to 4.13 K/W.