Heat Transfer Performance of Micro Heat Pipe with Trapezium-grooved Wick

A review of small heat pipes for electronics

“…They are fully driven by the capillary force, which depends mainly on the wicks but is negatively affected by gravity. Li et al [20] reported that metallic MHPs with a 6mm diameter (trapeziumgrooved wick with 60 teeth) can achieve 100 times the heat conduction coefficient of copper. Li et al [22] recommended that MHPs with the grooved wick of a small-angle dove-tailed structure or a rectangular or small-angle trapezoidal structure be employed to obtain better heat transfer performances.…”

“…Traditional HPs were made from metal, and MHPs with a diameter smaller than 2 mm can also be made from metal. Li et al [20] (Figure 1a) created an MHP with a digitally described, mathematically modeled trapezium grooved wick that had different groove structures manufactured by high speed spinning. Their analysis showed that better heat transfer performances can be obtained in MHPs with small-angle dovetailed, rectangular and small-angle trapezoidal grooved wick structures when the groove depth is 0.2-0.3 mm and the top-width-to-depth ratio is 1.2-1.5 [22].…”

“…As shown in Table 1, small HPs include traditional types with mini/micro wicks (referred to as mini/micro HP), small TPLs, small VCs, and small flat HPs with mini/micro wicks are listed. In this work, HP is either the generally name for all twophase capillary thermal control devices or a specific name for the traditional HPs invented in 1892 [19,20], excluding LHPs, CPLs, VCs, etc. Specifically, we still use the term MHPs, a widely used term for HPs with micro wicks and mini/micro tubes in many references.…”