Electrochemical Nucleation of Cyanide-free Alkaline Copper Plating from EDTA Bath

Electrochemical nucleation of cyanide-free alkaline copper plating from EDTA (ethylene diamine tetraacetic acid) bath was studied by means of cyclic voltammetry and chronoamperometry techniques.The deposition of copper follows three dimensional nucleation/growth mechanism. The analyzing of potentionstatic transients indicates that in the case of high negative potentials, the nucleation process of metal ions follows the instantaneous nucleation mechanism, in the case of low negative potentials, it is close to the progressive nucleation mechanism, and with the increase in overpotential the copper ion crystal nucleation is promoted, the maximum current Im gradually increases and the number of crystal nucleation increases.