THERMAL PERFORMANCE OF WICKLESS AND ORIENTATION INDEPENDENT THIN VAPOR CHAMBERS WITH WETTABILITY PATTERNED MICRO STRUCTURE

The wettability patterned micro structure (WPMS) arrays by laser etching are proposed to enhance the thermal performance of wickless thin vapor chamber (TVC). The effects of filling ratio and inclination angle on the thermal performance of wickless TVC with WPMS are investigated, and the untreated bare wickless TVC is also studied as comparison. The results show that the wickless TVC with WPMS can work stably at filling ratio ranging from 19.0% to 42.8%, and the optimum filling ratio is 42.8%. The maximum heat transfer capacity is 190 W with the lowest thermal resistance of 0.146 K/W. Since WPMS is superhydrophilic, it can provide nucleate sites to promote early onset nucleate boiling and capillary pressure to enhance the liquid supply. Thus, the wickless TVC with WPMS shows 10.98% lower thermal resistance and 18.75% higher maximum heat transfer capacity than that of the untreated bare wickless TVC. In addition, the thermal performance of wickless TVC with WPMS is insensitive to the orientation of the TVC.