Comprehensive atomistic modeling of copper nanowires-based surface connectors

In this paper, we study the mechanical behavior of surface nanoconnectors that are developed using two contacting sets of patterned copper (Cu) nanowire (NW) arrays. Specifically, comprehensive molecular dynamics (MD) simulations are conducted to establish the mechanics and the mechanisms involved at the atomic level that govern the mechanical integrity and ultimately the functionality of the formed bonds. All MD simulations were conducted using the embedded-atom and the Lennard-Jones potentials. Two aspects of the work were accordingly examined. The first considers the effect of temperature and diameter of an isolated Cu-NW on its tensile and fracture strength, as this determines the static strength and durability of the surface connector. The second considers the effect of NW diameter, separation distance between the NWs, overlapping depths, and temperature on the tensile strength of the nanoconnector. The results reveal that the formed surface joint between two interacting NWs can resist up to 70 nN in tension at an overlapping depth of 50 angstrom. It also reveals that increasing the nanowire diameter, the bonding failure becomes more surface dominated with insignificant plastic deformation outside the interface contacting region. These findings are useful in designing advanced conductive adhesives with tenable performance. (C) 2019 The Authors. Published by Elsevier Ltd.