Electroless plating catalyzed by 3D Cu NWs arrays on insulating substrate with enhanced adhesion

The catalytic electroless plating on insulating substrate holds great potential in additive manufacturing of printing circuits. A tri-layer interpenetration architecture was constructed to improve the peeling strength of Cu plating layer. The corona-treated PET was coated by epoxy resin, which served as ground floor for the rooting of Cu NWs. Benefiting from high aspect ratio, the ends of Cu NWs were exposed to surface. Which assembled into middle layer, forming 3D Cu NWs catalytic arrays. Along with Cu electroless plating, the catalytic arrays were gradually filled up and covered by the top layer of Cu plating. Both epoxy resin layer and Cu plating layer were deeply rooted by Cu NWs, which afforded the Cu plating layer with 5B adhesion, an increase of 86% compared to that of Cu MSs catalyst. Through investigating the subsidence behavior of Cu NWs in epoxy resin adhesive layer, the strengthen mechanism of peeling strength of Cu plating layer has been validated.