Design, fabrication and thermal performance of a novel ultra-thin vapour chamber for cooling electronic devices

In this work, a novel vapour-liquid channel-separated ultra-thin (0.4-mm-thick) vapour chamber fabricated via etching and diffusion bonding was designed for cooling electronic devices. The heat performance of ultra-thin vapour chamber was tested under five states, and micropillar arrays were etched into the chamber to study their effect on heat transfer. Additionally, infrared thermal imaging was performed to investigate the heat dissipation of cooling modules with and without the ultra-thin vapour chamber. The maximum heat transfer capacity of the ultra-thin vapour chamber in the horizontal state was 4.50 W, and the temperature difference was 4.75 degrees C. The experimentally measured values were very close to the theoretical capillary limit. Under normal and reverse gravities, the maximum heat transfer capacity changed by less than 11%. The effective thermal conductivity of the ultra-thin vapour chamber was 12000 W/(m.K), which is 30 times higher than that of pure copper. The cooling module with the ultra-thin vapour chamber exhibited better heat dissipation, thermal uniformity and thermal response properties. When the heating input power was 6 W, the heating block temperature, maximum surface temperature difference and equilibrium time of the cooling module with the ultra-thin vapour chamber were 8%, 54% and 32% lower, respectively, than those of the module without the ultra-thin vapour chamber. The proposed cooling solution is promising for heat dissipation problems in high-power portable electronic devices.