Collaborative Research: EAGER: Novel thermal interface material with Cu nanowire array

合作建议建议编号：#1140953/#1140121P.I.‘S：Costas Grigoropoulos/Renkun Chen研究所：加州大学伯克利分校/加州大学圣迭戈分校热接口材料在电子设备的热管理中发挥着关键作用。现有的材料，如润滑脂和焊料，将不足以冷却功率消耗水平越来越高的器件。本研究的目的是开发一种基于铜纳米线阵列的高性能热界面材料。与现有材料相比，新材料的接触热阻将降低一个数量级。为了实现这一目标，将通过电镀多孔阳极氧化铝膜来制备垂直排列、致密的单晶铜纳米线阵列，其直径、间距和堆积密度都可以很好地控制。将利用微制造器件对单个纳米线的力学、热学和电学性质进行基础研究。铜纳米线阵列的界面和整体热阻将使用灵敏的瞬时热反射技术来表征。智能优点：铜纳米线同时具有两个重要特征，使其成为高性能热界面材料的独特候选者：高导热系数和高机械柔度。由于铜纳米线阵列具有高的导热系数和约50%的高堆积密度，与现有的热界面材料相比，具有较低的热接触阻。此外，纳米线的大长径比(200：1)使其在承受热应力时具有很高的柔韧性，因此在热循环后仍能保持高的热性能。拟议的研究课题将促进对与热封装应用有关的铜纳米线的机械和电热性能的理解，无论是单独还是作为一个阵列，并将导致具有优异的热和机械性能的新型热界面材料的开发。更广泛的影响：热接口材料是微电子行业追求越来越高的时钟速度的关键热封装元件之一。拟议的基于铜纳米线的接口可能成为一种颠覆性的使能技术，用于开发性能更高的电子设备，因此可能会产生巨大的社会影响。教育和外展活动将紧密结合到该计划中。通过开发新的课程和招收本科生参与研究，该项目将培养下一代热能工程师，他们将受到迷人的纳米科学和我们社会面临的重大技术挑战的激励。拟议的外展计划将利用伯克利分校和加州大学圣地亚哥分校促进多样性的努力，并将使K-12和代表性不足的学生受益。

Collaborative ProposalsProposal Numbers: #1140953 / #1140121P.I.'s: Costas Grigoropoulos / Renkun ChenInstitution: University of California-Berkeley / University of California-San DiegoThermal interface materials play a critical role in thermal management of electronic devices. Current materials, such as greases and solders would be insufficient for cooling the devices with increasingly higher power dissipation level. The objective of this research is to develop a high performance thermal interface material based on copper nanowire array. The new material will have one order of magnitude lower thermal contact resistance compared to the existing ones. To achieve this goal, vertically aligned, dense arrays of single crystalline copper nanowires with well-controlled diameters, spacing and packing density will be synthesized by electroplating through porous anodic alumina membranes. Fundamental studies on mechanical, thermal and electrical properties of individual nanowires will be carried out by using micro-fabricated devices. Interfacial and bulk thermal resistances of copper nanowire arrays will be characterized using a sensitive transient thermo-reflectance technique. Intellectual Merit: Copper nanowires simultaneously possess two important features that make them a unique candidate for high performance thermal interface materials: high thermal conductivity and high mechanical compliance. Because of the high thermal conductivity and the high packing density of approximately 50%, copper nanowire array has a lower thermal contact resistance compared to the state of the art thermal interface materials. Moreover, the large aspect ratio of the nanowires ( 200:1) makes them highly compliant when subjected to thermal stress, hence the high thermal performance can be retained after thermal cycling. The proposed topics of investigation will advance the understanding of mechanical and electro-thermal properties of copper nanowires pertaining to thermal packaging applications, both individually and collectively as an array, and will lead to the development of a new class of thermal interface materials with superior thermal and mechanical properties. Broader Impacts: Thermal interface material is one of the key thermal packaging components that are highly demanded by microelectronic industry pursuing increasingly higher clock speed. The proposed copper nanowires based interfaces could become a disruptive enabling technology for developing electronic devices with higher performance, hence can potentially make a tremendous societal impact. Educational and outreach activities will be tightly integrated into the program. By developing new curriculum and recruiting undergraduate students into the research, the program will educate next generation thermal engineers who will be motivated by fascinating nanosciences and the grand technological challenges faced by our society. The proposed outreach programs will leverage the efforts of both the Berkeley and UCSD campuses for promoting diversities, and will benefit K-12 and under-represented students.