Optimization design of grooved condenser wick structures in a vapor chamber for electronic cooling applications

This article focuses on the layout design of grooved condenser wick structures to improve the surface temperature uniformity for vapor chamber heat spreaders. The design is formulated as a general “area-to-point” (AP) heat conduction problem in disk-shaped configuration. The fundamental relationship between the heat transfer performance and the grooved wick layouts is discussed from the perspective of constructal optimization. The first-order constructs of the heat generating disk are theoretically optimized when the constraint of minimum length scale is imposed for manufacturability of the high conductivity channels (HCCs) (wick grooves). According to the first-order constructs, the disk domain is divided into a number of identical sectors whose boundaries are all adiabatic. A new growth simulator is then developed to obtain the full constructal layouts, where the HCCs are treated as being alive and the optimization is viewed as an adaptive growth procedure. In each sector, the HCCs sprout from the disk center, extend toward the perimeter, and finally converge at a unique topology that exhibits dichotomous, hierarchical, and branching characteristics. Numerical comparison indicates that the new wick structure improves both the temperature uniformity and the capillary pressure, which can contribute to the vapor chamber heat spreaders with better thermal performance.