Nanoporous membrane device for ultra high heat flux thermal management
Nanoporous membrane device for ultra high heat flux thermal management
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DOI：
10.1038/s41378-018-0004-7
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发表时间：
2018-02-26
影响因子：
7.9
通讯作者：
Wang, Evelyn N.
中科院分区：
文献类型：
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作者：
Hanks, Daniel F.;Lu, Zhengmao;Wang, Evelyn N.
高功率密度电子产品受到当前热管理解决方案的严重限制，这些解决方案无法消散必要的热通量，同时保持安全结温以实现可靠运行。我们设计、制造并通过实验表征了一种微流体装置，该装置利用纳米多孔硅膜的蒸发来实现超高热通量耗散。该膜具有类似于 100 nm 直径的孔，即使使用戊烷和 R245fa 等低表面张力流体，也能产生高毛细管压力。悬浮的超薄膜结构有利于高效的液体输送，同时将粘性压力损失降至最低。我们使用干涉光刻和反应离子蚀刻在硅中制造膜，然后将其粘合到高渗透性硅微通道阵列上，以创建双孔吸芯，从而实现高毛细管压力和增强的渗透性。背面由薄膜铂加热器和电阻温度传感器组成，分别用于模拟晶体管的散热并测量温度。我们在环境室的纯蒸汽环境条件下对器件进行了实验表征。因此，我们在 0.172 mmx 10 mm 的面积上使用戊烷证明了 665 +/- 74 W/cm(2) 的热通量，并且从加热的基板到环境蒸汽的温升为 28.5 +/- 1.8 K。该热通量由蒸发面积归一化，是迄今为止在纯蒸发状态（即没有泡核沸腾的情况下）中报道的最高热通量。实验结果与捕捉悬浮膜结构中的热传导以及液-汽界面处的非平衡和亚连续效应的高保真模型非常吻合。这项工作表明，基于蒸发膜的方法有望在高性能电子产品的大面积上实现高效、高通量的热管理策略。
High power density electronics are severely limited by current thermal management solutions which are unable to dissipate the necessary heat flux while maintaining safe junction temperatures for reliable operation. We designed, fabricated, and experimentally characterized a microfluidic device for ultra-high heat flux dissipation using evaporation from a nanoporous silicon membrane. With similar to 100 nm diameter pores, the membrane can generate high capillary pressure even with low surface tension fluids such as pentane and R245fa. The suspended ultra-thin membrane structure facilitates efficient liquid transport with minimal viscous pressure losses. We fabricated the membrane in silicon using interference lithography and reactive ion etching and then bonded it to a high permeability silicon microchannel array to create a biporous wick which achieves high capillary pressure with enhanced permeability. The back side consisted of a thin film platinum heater and resistive temperature sensors to emulate the heat dissipation in transistors and measure the temperature, respectively. We experimentally characterized the devices in pure vaporambient conditions in an environmental chamber. Accordingly, we demonstrated heat fluxes of 665 +/- 74 W/cm(2) using pentane over an area of 0.172 mmx 10 mm with a temperature rise of 28.5 +/- 1.8 K from the heated substrate to ambient vapor. This heat flux, which is normalized by the evaporation area, is the highest reported to date in the pure evaporation regime, that is, without nucleate boiling. The experimental results are in good agreement with a high fidelity model which captures heat conduction in the suspended membrane structure as well as non-equilibrium and sub-continuum effects at the liquid-vapor interface. This work suggests that evaporative membrane-based approaches can be promising towards realizing an efficient, high flux thermal management strategy over large areas for high-performance electronics.