Chen Lu, Liu Te-Huan, Wang Xiangze, Wang Yandong, Cui Xiwei, Yan Qingwei, Lv Le, Ying Junfeng, Gao Jingyao, Han Meng, Yu Jinhong, Song Chengyi, Gao Jinwei, Sun Rong, Xue Chen, Jiang Nan, Deng Tao, Nishimura Kazuhito, Yang Ronggui, Lin Cheng-Te, Dai Wen
Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo, 315201, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2023 Aug;35(31):e2211100. doi: 10.1002/adma.202211100. Epub 2023 Jun 20.
The rapid development of highly integrated microelectronic devices causes urgent demands for advanced thermally conductive adhesives (TCAs) to solve the interfacial heat-transfer issue. Due to their natural 2D structure and isotropic thermal conductivity, metal nanoflakes are promising fillers blended with polymer to develop high-performance TCAs. However, achieving corresponding TCAs with thermal conductivity over 10 W m K at filler content below 30 vol% remains challenging so far. This longstanding bottleneck is mainly attributed to the fact that most current metal nanoflakes are prepared by "bottom-up" processes (e.g., solution-based chemical synthesis) and inevitably contain lattice defects or impurities, resulting in lower intrinsic thermal conductivities, only 20-65% of the theoretical value. Here, a "top-down" strategy by splitting highly purified Ag foil with nanoscale thickness is adopted to prepare 2D Ag nanoflakes with an intrinsic thermal conductivity of 398.2 W m K , reaching 93% of the theoretical value. After directly blending with epoxy, the resultant Ag/epoxy exhibits a thermal conductivity of 15.1 W m K at low filler content of 18.6 vol%. Additionally, in practical microelectronic cooling performance evaluations, the interfacial heat-transfer efficiency of the Ag/epoxy achieves ≈1.4 times that of the state-of-the-art commercial TCA.
高度集成微电子器件的快速发展，引发了对先进导热胶粘剂（TCA）的迫切需求，以解决界面传热问题。由于其天然的二维结构和各向同性的热导率，金属纳米片有望作为填料与聚合物共混，以开发高性能的TCA。然而，迄今为止，在填料含量低于30体积%的情况下，制备热导率超过10 W m K的相应TCA仍然具有挑战性。这一长期存在的瓶颈主要归因于，目前大多数金属纳米片是通过“自下而上”的工艺（如基于溶液的化学合成）制备的，不可避免地含有晶格缺陷或杂质，导致本征热导率较低，仅为理论值的20-65%。在此，采用一种“自上而下”的策略，通过分割具有纳米级厚度的高纯度银箔来制备本征热导率为398.2 W m K的二维银纳米片，达到理论值的93%。直接与环氧树脂共混后，所得的Ag/环氧树脂在18.6体积%的低填料含量下，热导率为15.1 W m K。此外，在实际的微电子冷却性能评估中，Ag/环氧树脂的界面传热效率达到了最先进的商用TCA的约1.4倍。
