Experimental investigation on the thermal characteristics of ultrathin vapour chamber with in-plane bending

Abstract

• Probing the effects of in-plane bending on the UTVCs. • Systematic exploration of the heat transfer mechanism behind the in-plane bending effects. • A model to predicting the maximum heat transfer capacity and thermal resistance with given in- plane bending conditions was established. Although many works have been published on designing ultrathin vapour chambers (UTVCs), but no one has analyzed the effect of in-plane bending on the thermal characteristics of UTVCs. However, UTVCs often need to be designed into in-plane bending shapes to meet the limited and strict application space in portable electronic devices. Therefore, this work makes grate efforts to ascertaining the effect of in-plane bending on the thermal characteristics of UTVCs with thicknesses below 0.6 mm. UTVCs with four bending angles (0°/45°/90°/135°) and three bending radii (R10/R15/R20) were fabricated based on brazing, and the effects of filling rate and bending on the thermal characteristics of UTVC were investigated. The results show that the optimal filling rate of UTVC was 100%, the large bending angle and small bending radius lead to the increase of evaporation temperature and thermal resistance. The maximum heat transfer capacity of UTVC decreases by more than 27% when the bending angle change from 0° to 135°. In addition, a model for predicting maximum heat transfer capacity and thermal resistance was developed. The variation trend of predicted value was the same as experimental value, and the minimum error less than 3%.