Vertically aligned carbon nanotube based thermal interface materials for low contact pressure and low ambient pressure applications
Vertically aligned carbon nanotube based thermal interface materials for low contact pressure and low ambient pressure applications
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基于垂直排列碳纳米管的热界面材料，适用于低接触压力和低环境压力应用
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
B. Cola
中科院分区：
文献类型：
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作者：
A. Haight;C. Green;B. Cola
高性能热界面材料(TIMS)是维持现代电子设备在其温度允许范围内的重要工具。尤其具有挑战性的是不能承受系统封装中的高接触压力的敏感电子设备。通常依靠施加在TIM上的压力来最小化焊接线厚度、保持对齐并最大化接触面积。在这项工作中，研究了金属衬底上垂直排列的碳纳米管(CNT)森林作为一种潜在的低接触压力应用解决方案。基于碳纳米管的TIM在极低的接触压力下具有很高的导热系数，并且在机械变形时不会退化，这为当前TIM解决方案提供了更好的替代方案。此外，碳纳米管阵列接口从低温到高温都是干燥和化学稳定的，从而简化了安装并防止热泵抽出。在接触压力仅为10千帕的情况下，CNT TIM原型提供了1400W/m2K(电阻为7cm2-K/W)的电导，大大超过了可比的商用TIM。接下来，为了评估需要较大TIM厚度和机械顺应性的应用的性能，将三个单独的碳纳米管阵列垂直堆叠并使用薄聚合物层粘合在一起。堆叠的基于碳纳米管TIM的间隙垫具有高达900μm的交叉面厚度。当堆叠时，碳纳米管TIM仍提供优异的热性能，导电率接近900W/m2K。最后，在真空条件下对碳纳米管TIMs进行了测试，以评估其在航空航天应用中的潜在性能。
High performance thermal interface materials (TIMs) are an essential tool for maintaining modern electronics within their temperature allowances. Especially challenging are sensitive electronics that cannot tolerate high contact pressures in the system packaging. Pressure applied to the TIM is often relied upon to minimize the bond line thickness, maintain alignment, and maximize contact area. In this work, vertically aligned carbon nanotube (CNT) forests on metal substrates are investigated as a potential solution for low contact pressure applications. Carbon nanotube based TIMs have high thermal conductance at very low contact pressure and do not degrade when mechanically deformed, which offers the potential for a superior alternative to the current TIM solutions. Also, CNT array interfaces are dry and chemically stable from cryogenic to elevated temperatures, simplifying installation and preventing thermal pump-out. At a contact pressure of only 10 kPa, a prototype CNT TIM delivered a conductance of 1,400 W/m2K (resistance of 7 cm2-K/W), significantly outperforming comparable commercial TIMs. Next, to evaluate performance for applications requiring large TIM thicknesses and mechanical compliance, three individual CNT arrays were stacked vertically and bonded using a thin polymer layer. The stacked CNT TIM based gap pads had cross plane thickness of up to 900 μm. When stacked, the CNT TIMs still provided excellent thermal performance, with conductances approaching 900 W/m2K. Finally, the CNT TIMs were tested under vacuum conditions to evaluate their potential performance in aerospace applications.