銅ナノワイヤ面ファスナーの接着強度向上に向けた影響因子の最適化

抄録

In recent years, connecting techniques using conductive nanomaterials imitating gecko's feet, for example, metal nanowires, carbon nanotubes and conductive polymer materials as a surface fastener have been reported. These connecting techniques utilize van der Waals force generated between the surfaces of nanomaterials. Recently, we have developed the copper nanowire surface fasteners (Cu NSF) as a conductive connector. Since copper has high electrical conductivity and is inexpensive, the Cu NSF can be expected to be practically used as a new surface mounting technique. Moreover, Cu NSF can be connected at room temperature utilizing van der Waals force, so that it is possible to avoid the damage to electronic parts during solder reflow process. However, the adhesion strength of current Cu NSF is still small as compared with traditional solders. The reason is considered that the contact areas of the nanowires were not sufficient because the nanowires collided and collapsed during connecting. In this research, we attempted to increase the contact area of nanowires for improving adhesion strength of Cu NSF. The adhesion strength of the Cu NSFs having nanowires with 100 nm and 400 nm diameter reached the largest value, and increasing with the increase of preload. This investigation showed that the contact areas of nanowires increased and mechanical entanglement of nanowires occurred because of increasing the preload of connecting.