EAGER: Processing and Characterization of Novel Indium-graphene and Copper-graphene Composites for Heat Spreader Applications

AbstractThis Early概念探索性研究赠款（EAGER）赠款为新型铟-石墨烯和铜-石墨烯复合材料的加工和表征提供资金，用于散热器应用。加工步骤将包括用分散的氧化石墨烯轧制铟和铜箔，然后进行中间加热，以防止复合材料中石墨烯的团聚。通过将氧化石墨烯还原成石墨烯形成的金属氧化物将通过铟助熔剂或通过使铜-石墨烯复合物在较高温度下经受氢气来去除。复合材料中石墨烯的尺寸和均匀分布将通过先进的方法来表征，包括扫描和透射电子显微镜。热导率将通过实验确定为温度和复合材料中石墨烯的体积分数的函数。将进行石墨烯和基质金属之间的界面热导率的测量，以验证它不是实现复合材料的高热导率的限制因素。将进行复合材料的热传输性能的建模，以评估微结构特征，界面热导率和石墨烯和金属基体的热导率的重要性。半导体晶片将使用铟-石墨烯复合材料焊料结合到铜-石墨烯复合材料。结合的结构将受到热循环，以确定稳定性和抵抗失效的剥离。如果成功，这项研究的结果将导致显着改善的热界面材料和散热器的导热性。热能耗散的瓶颈将被消除，这对高频和大功率电子器件和激光器的可靠性和操作非常关键。本研究的主要目标是加工具有均匀分散的石墨烯的石墨烯复合材料并实现高散热器能力。根据各个组分的性质确定热输运性质将有助于确定石墨烯的贡献，石墨烯被认为是未来的新型电子材料。本项目开发的低成本制造方法将使半导体和激光封装技术能够克服热管理问题。

AbstractThis EArly-concept Grants for Exploratory Research (EAGER) grant provides funding for the processing and characterization of novel indium-graphene and copper-graphene composites for heat spreader applications. The processing steps will consist of rolling indium and copper foils with dispersed graphene oxide followed by intermediate heating so that agglomeration of graphene in the composites is prevented. The metal oxide formed by reduction of graphene oxide to graphene will be removed by indium flux or by subjecting the copper-graphene composite to hydrogen at higher temperature. The size and uniform distribution of graphene in the composites will be characterized by advanced methods that include scanning and transmission electron microscopy. The thermal conductivity will be determined experimentally as a function of temperature and volume fraction of graphene in the composites. Measurement of interfacial thermal conductance between graphene and the matrix metal will be performed to verify that it is not a limiting factor to achieve high thermal conductivity of the composites. Modeling of the thermal transport properties of the composites will be carried out to evaluate the importance of microstructural features, interfacial thermal conductance, and thermal conductivity of graphene and metal matrix. Semiconductor wafers will be bonded to the copper-graphene composites using the indium-graphene composite solder. The bonded structures will be subjected to thermal cycling to determine the stability and resistance to failure by debonding.If successful, the results of this research will lead to significant improvements in the thermal conductivity of the thermal interface material and heat spreader. The bottleneck to thermal energy dissipation, which is very critical to the reliability and operation of high frequency and high power electronic devices and lasers, will be eliminated. The primary goal of the present research is to process graphene composites with uniform dispersion of graphene and achieve high heat spreader capability. Determination of thermal transport properties in terms of the properties of the individual components will be helpful to determine the contribution from graphene which is considered the future novel electronic material. Low cost manufacturing methods developed in this project will enable semiconductor and laser packaging technologies to overcome the thermal management problems.