Powder sintered flat micro-heat pipe with wettability modification

Abstract

Flat micro-Heat Pipe (FHP) provides an excellent solution to the heat dissipation problem of an electronic chip by the gas–liquid two-phase flow. Therefore, the liquid channels and the gas channels are part of the FHP. It determines the performance of the FHP. To this end, these channels were optimized by infiltration modification to accelerate the gas-liquid circulation. In this work, the wick underwent hydrophilic treatment by chemical corrosion and the solutions selected were KOH and (NH4)2S2O8. The shell surface undergoes hydrophobic treatment by electrodeposition with a mixture of zinc-nickel ions. The thermal transfer performance of the Hydrophilic Wick FHP (HW-FHP) and the Hydrophobic Shells FHP (HS-FHP) was analyzed. The results show that the maximum thermal power of the HW-FHP is 10.8 W, 9.1% higher than that of the Untreated FHP (UFHP). The HS-FHP is 11.9 W, 20% higher than that of the UFHP. The HW has a high capillary force, resulting in faster fluid flow. The vapor flow channels made up of the HS have a low resistance to the vapor flow. The hydrophobic surface can reduce the droplet diameter and prevent blocked vapor flow channels.