Research and optimization design of limited internal cavity of ultra-thin vapor chamber

Abstract

With the miniaturization and integration of portable devices, ultra-thin vapor chamber (UTVC) is required to have thinner thickness and better heat transfer performance. However, the reduction in thickness usually causes a decrease in heat transfer capability. Thus, it is necessary to optimize the internal structure to improve the heat transfer performance. In this study, the relationship between the thickness and width of the steam chamber and the channel coefficient (Sv) was studied. When the thickness of the steam chamber is less than 0.3 mm, Sv increases rapidly as the thickness decreases. At the same time, Sv also rises rapidly with the decrease of steam channel width (Wv ≤ 2 mm). For the layered structure, the influence of different support column types on the vapor pressure drop was analyzed. It indicates that reducing the diameter and spacing of the support columns simultaneously is a good way to balance the support effect and vapor pressure drop. The calculation method for solving the optimal values of the spaced structure is derived. For ultra-thin limited space, the sum of Fv and Fl of the optimal spaced structure is smaller than the layered structure, which is more suitable for UTVC.