Heat transfer characteristics of chip heat sink based on composite wick micro heat pipe array

Abstract

A double L-shaped heat pipe sink that uses a micro heat pipe array is proposed for heat dissipation and temperature uniformity in high-power electronics chip cooling for the first time in this work. The radiator is composed of two L-shaped micro heat pipe arrays filled with copper foam wick (the composite wick structure) and aluminum flat fins, which can reduce the temperature of hotspots of electronics effectively and has good inclination adaptability. Through experiments, the heat transfer performance is studied under different copper foam filling lengths, liquid filling rates, and inclination angles. Then, a numerical simulation of the effect of different fin parameters on the radiator is conducted using Icepak. The composite wick structure effectively enhances the heat transfer capability of the radiator. Results show that the average thermal resistance of the micro heat pipe array with a composite wick structure is 0.258 K/W, indicating a 23 % reduction compared with that of a single wick structure double L shape heat pipe sink. The double L shape heat pipe sink solves the phenomenon of chip temperature jump caused by the hotspots of high heat flux. The average temperature of the chip surface can be controlled below 62 ℃ when the localized heat flux is 200 W/cm2. Simulation results show that optimization of the fin structure can stabilize the temperature of the 214 W chip at 70.1 ℃, which is reduced by 8.7 % than before optimization.