Heat transfer enhancement of the ultra-thin flat heat pipe integrated with copper-fiber bundle wicks

The rapid size shrinkage and the increasing power of the chip made it increasingly challenging to dissipate the heat generated by electronics. Ultra-thin flat heat pipes possessed the characteristics of high thermal conductivity, slender shape, and absence of moving parts, making them an effective solution for heat dissipation in small spaces. In this paper, the composite wicks made by copper-fiber bundle were designed and fabricated. The heat transfer performance of the ultra-thin heat pipe was experimentally investigated with a focus on the effects of wick design. The weaving method used in the composited wick affected the thermal performance of the ultra-thin heat pipe. The results indicated that the wicks with heterostructure increased the maximum heat transfer capacity by 6 W when compared with the homogeneous structures. The single-layer copper mesh design resulted in a 13 W increase in maximum heat transfer capacity compared to the double-layer design.