Comparison of Structural Properties of Copper Deposits from Sulfate and Pyrophosphate Electrolytes

Aluminum is quite often plated to combine the advantages of the light metal with modified surface properties. In this study, copper strike electrodeposits obtained from cyanide and pyrophosphate strike baths were compared in terms of microstructure, and copper pyrophosphate strike was found to yield smoother deposits. Furthermore, about 50 m thick copper depositions on the strike plated aluminum surface, were prepared from acid copper sulfate and copper pyrophosphate electrolytes to compare structural properties of the deposits. Comparison and characterization of copper electrodeposits from copper sulfate and pyrophosphate electrolytes were performed by potentiometry, SEM, roughness, and XRD analyses. Smoother and finer grained copper deposits were obtained from pyrophosphate electrolyte especially at low current densities.