AN EXPERIMENTAL-STUDY OF METAL DISTRIBUTION IN PULSE PLATING

An experimental study has been made of the metal distribution on a rotating disk electrode for the pulse plating of copper from an acidic copper sulfate bath. The local metal thickness was measured as a function of the applied pulse current density, pulse period, duty cycle, and ratios of the ohmic electrolyte resistance to the mass transfer and kinetic resistances of the electrodeposition reaction. A dimensional analysis was used to identify the key dimensionless parameters. The uniformity of metal distribution was experimentally examined over the range of the dimensionless pulse current densities of 0.1-10, dimensionless pulse periods of 0.0014-0.14, duty cycles of 0.01-1.0, dimensionless limiting current densities of 4.6-59, and dimensionless exchange current densities of 0.078-0.98.