The Effects Plated Layers Have on Single Spot Contact Resistance

The present paper addresses the impact a two-layer plating system has on the constriction resistance of a single contact spot. The method used to estimate constriction resistance is the capacitance model provided by Holm. This model is modified by considering how each layer changes the equipotential surfaces in each layer. Subsequently, using a weighting method in the Holm equation, that represents the change in contact capacitance, the constriction resistance is estimated. Moreover, numerical methods are used to perform the necessary calculations to estimate these effects. The system chosen to conduct this analysis is a typical gold over nickel plating on Phos Bronze base metal. In this case the resistivities are significantly different and the results indicate that significant effects are seen as the thickness of the gold and nickel layers are varied.