Development of Micro Heat Pipes Embedded in Laminate Substrates for Enhanced Thermal Management (TM) for Printed Wiring Boards (PWBs).

摘要

The objective of this work is the development of a process to fabricate an axial grooved heat pipe embedded in printed wiring board (PWB) technology and to evaluate is thermal, mechanical performance, and reliability. The results clearly show that the embedded heat pipe was operable and the heat transfer through the substrate was enhanced. However, the heat pipe was limited in the power input it could handle, as heat pipe failure occurred around 10 W by delamination of the PWB and subsequent loss of hemeticity and loss of the working fluid. After failure occurs, the heat pipe begins to behave as an uncharged heat pipe for the corresponding input the whole PWB starts increasing until it reaches the temperature distribution of the uncharged heat pipe for the corresponding input power. The development of a hemetic structure within the channel structure. Since the operation of the wick in the heat pipe is strongly dependent on the ability of the working fluid to wet the wick, the wetting angle of the plating material was measured for the various materials Option available (bare laminate, copper plating, other plating). The physical structure of the embedded heat pipes was analyzed by finite element analysis (FEA). The FEM results were compared with the experimental data to determine failure mode.