Yang Cheng, Cui Xiaoya, Zhang Zhexu, Chiang Sum Wai, Lin Wei, Duan Huan, Li Jia, Kang Feiyu, Wong Ching-Ping
Division of Energy and Environment, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
School of Materials Science and Engineering, Georgia Institute of Technology, 771, Ferst Dr, Atlanta, Georgia 30332, USA.
Nat Commun. 2015 Sep 3;6:8150. doi: 10.1038/ncomms9150.
Fractal metallic dendrites have been drawing more attentions recently, yet they have rarely been explored in electronic printing or packaging applications because of the great challenges in large-scale synthesis and limited understanding in such applications. Here we demonstrate a controllable synthesis of fractal Ag micro-dendrites at the hundred-gram scale. When used as the fillers for isotropically electrically conductive composites (ECCs), the unique three-dimensional fractal geometrical configuration and low-temperature sintering characteristic render the Ag micro dendrites with an ultra-low electrical percolation threshold of 0.97 vol% (8 wt%). The ultra-low percolation threshold and self-limited fusing ability may address some critical challenges in current interconnect technology for microelectronics. For example, only half of the laser-scribe energy is needed to pattern fine circuit lines printed using the present ECCs, showing great potential for wiring ultrathin circuits for high performance flexible electronics.
分形金属树枝状晶体近来受到了更多关注，然而由于大规模合成面临巨大挑战且在此类应用中的认识有限，它们在电子印刷或封装应用中很少被探索。在此，我们展示了在百克规模上可控合成分形银微树枝状晶体。当用作各向同性导电复合材料（ECC）的填料时，独特的三维分形几何构型和低温烧结特性使银微树枝状晶体具有0.97体积%（8重量%）的超低渗流阈值。超低渗流阈值和自限熔断能力可能解决当前微电子互连技术中的一些关键挑战。例如，使用当前的ECC印刷精细电路线路时，只需一半的激光划刻能量就能进行图案化，这显示出在高性能柔性电子器件的超薄电路布线方面具有巨大潜力。
