Study on morphology of copper deposited onto aluminium by immersion plating from an oxalate bath containing perchloric acid

The structural characteristics of copper deposits resulting from immersion plating of copper are presented. In this study halide is replaced by perchloric acid, which is found to effectively break down the impervious oxide film from aluminium surface and to facilitate copper plating. Increase in copper concentration results in a smooth deposit, showing layered structure where crystallite grows in fine globular shape. Perchloric acid concentration has a significant effect on the deposit morphology. Increase in its concentration mainly affects the crystallite size and its distribution on the substrate surface. At higher perchloric acid concentrations no dendrite formation is observed but surface corrosion is initiated. Increase in plating temperature results in the nodular growth and also surface corrosion. The activation energy calculated from the Arrhenius plot is found to be 34.19 kJ mol−1.