Interferometric investigation of the kinetics of the levelling process during bright electroplating

Abstract

An interferometric method was devised for the direct quantitative investigation of the levelling ability of electrolytic baths used in the bright plating processes. The method makes it possible to measure in situ the main parameters of the depositing galvanic layer. The experimental conditions resemble those prevailing in industry; the electrolyte circulates, is continuously filtrated and is air agitated. The method is rapid and can be automated. Measurements are performed according to a preset time programme. It was applied to the study of the levelling ability of different baths for bright acid copper plating in which the cathode was an unmodulated gramophone plate matrix. The deposition rate in the grooves and onto the smooth portions of the electrode surface was established. From the data obtained the full pattern of the time dependence of the cathode profile was reconstructed.