Copper/parylene core/shell nanowire surface fastener used for room-temperature electrical bonding

The traditional bonding technology in electronic assembly relies on high-temperature processes, such as reflow soldering or curing of adhesives, which result in undesired thermal excursions and residual stress at the bonding interface. Therefore, there is an urgent need to attach electronic components on the circuit board with good mechanical and electrical properties at room temperature. In this paper, a room-temperature electrical surface fastener consisting of copper/parylene core/shell nanowire (NW) arrays were prepared, and van der Waals (VDW) forces were utilized to interconnect the core/shell NWs. Interestingly, the Parylene C film becomes conductive due to dielectric breakdown when the thickness of it is miniaturized to nanoscale. Our electrical surface fastener exhibits high macroscopic adhesion strength (∼25 N/cm ²) and low electrical resistance (∼4.22 × 10^-2 Ω·cm²). Meanwhile, a new theoretical model based on VDW forces between the NWs is proposed to explain the adhesion mechanism of the core/shell structure.