Heat Transfer Performance Evaluation of Ultrathin Flexible Heat Pipes with Vapor Channels Formed by Micro-imprint

doi:10.3901/JME.2024.14.329

Abstract

Abstract: The manufacturing equipment and fabrication process of ultrathin flexible heat pipe(UFHP) with PMMA casings are introduced in this study. A micro-column array fabricated by a separate micro-imprint mold and a high-temperature sintered multilayer copper mesh are used as vapor channel and wick, respectively, and UFHPs with a thickness of 0.67mm is fabricated. The effects of micro-imprint temperature, pressure, and dwell time on the forming of micro-pillars were studied. The test devices and the experimental methods of the heat transfer performance of UFHPs are introduced. The experimental results showed that the optimal liquid filling amount is 350-400 μL and the highest thermal conductivity reached 924.1 W/(m•K). The thermal conductivity of the UFHP is still 1.16 times that of copper with a bending angle of 90°. In summary, the UFHPs with PMMA casings fabricated by micro-imprint have the advantages of flexible structure, low cost, and low vapor flow resistance, and are an ideal solution to the heat dissipation problem of flexible wearable electronic devices.

Key words: flexible heat pipe, ultrathin, micro-imprint, vapor channel, polymer

CLC Number:

TK124

SUN Yalong, TANG Yong, LIANG Fuye, ZHANG Shiwei, WU Chunxia, SHUAI Mao, TANG Heng. Heat Transfer Performance Evaluation of Ultrathin Flexible Heat Pipes with Vapor Channels Formed by Micro-imprint[J]. Journal of Mechanical Engineering, 2024, 60(14): 329-337.

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