Rapid metallization by copper electroplating on insulating substrate using silver nanowires conductive composite as seed layer

Abstract

In this work, a novel method is proposed by introducing silver nanowires (AgNWs) into (3,4-ethylenedioxythiophene)-poly (styrene sulfonate) (PEDOT:PSS) as conductive seed layer to realize the direct copper electroplating on insulating substrates. The AgNW network exhibits an extremely low sheet resistance below 10 Ω sq−1 with an area density of 6 μg cm−2 thus it can activate the copper electroplating rapidly. Only by applying electroplating time of 10 s under 3 A/dm2, the as-plated copper covers the whole substrate surface from the macroscopic surfaces. Peel strength is examined to evaluate the practical performances of as-plated copper on AgNWs, demonstrating a sound as-plated copper layer with outstanding adhesion on substrate. Surface morphology analysis of the composites under different electroplating time is employed to study the depositing process of copper atoms on AgNWs. Unlike other plating seed layer methods of slow deposition along the conductive layer from top to bottom, copper ions are preferred to be reduced rapidly at the junction of AgNWs forming crystal nucleus which serve as the subsequent deposition sites. As a result, the entire surface of the insulating substrate is covered by the as-plated copper rapidly.