Development of miniature loop heat pipes for the thermal control of laptops

Thermal management of laptops is becoming increasingly challenging task due to the high heat flux associated with the microprocessors and limited available space for the integration of the thermal control device inside the cabinet. In this paper, results from the investigation of two different designs of miniature Loop Heat Pipe (mLHP) for thermal control of compact electronic devices including notebooks have been discussed. Two prototypes of mLHP, one with a disk shaped evaporator of 30 mm in diameter and 10 mm thick, and the other with a rectangular shaped evaporator of 45×35 mm2 planar area and 5 mm thick, were designed to handle heat fluxes of up to 50 W/cm2. Total thermal resistance of these mLHPs lies in the range of 1 to 5 °C/W. In addition to this, two new designs of the mLHP pertaining to enhance the heat transfer inside the evaporation zone and to develop the loop evaporator with thickness as small as 3 mm are discussed. In conclusions, the designed mLHPs were able to satisfy the thermal and design requirements of the current laptop equipments and can be classified as potential candidates for cooling of the compact electronic devices with restricted space and high heat flux chipsets.