Thermal performance enhancement of vapor chamber with modified thin screen mesh wick by laser etching

In order to cope with high heat flux of miniaturized electronic devices in narrow space, vapor chamber has been developed towards ultra-thin thickness. In this study, a novel design of thin screen mesh with superhydrophilic micro structure was firstly proposed to enhance the thermal performance of thin vapor chamber (TVC). A layer of 0.12 mm thick screen mesh was employed as evaporator wick. The central area of the thin wick above heat input region was treated by laser etching to form superhydrophilic micro structure for improving capillary capability and providing nucleation sites. The upper sheet without wick was stamped to form support columns for preventing deformation and providing axial thermal conduction passage. Three TVCs (70 x 70 x 1.5 mm(3)) with various laser-etching area ratio (LEAR) of 0%, 66.6% and 83.3% were fabricated to study thermal performance of the novel TVCs. The results indicated that the novel evaporator mesh wick could remarkably enhance thermal performance of the TVCs. With LEAR increasing from 0% to 83.3%, the lowest thermal resistance R-VC of TVC dropped from 0.431 K/W to 0.328 K/W, i.e. decreased 23.9%, and the maximum heat transfer capacity increased from 100 W to 120W, i.e. increased 20%.