A THEORETICAL-ANALYSIS OF THE EFFECT OF INERT BLOCKING-AGENT ON THE GALVANOSTATIC PULSE PLATING

A theoretical study on the effect of inert blocking inhibitors on the pulse electrodeposition of metal is presented. The model can be used t o evaluate the influence of inhibitors with various adsorption and inc lusion characteristics under the current-pulse operating condition. It is shown in the simulation that under normal plating condition of sma ll additive concentration, the additive surface coverage is larger in the pulse operating mode than in direct-current mode. The characterist ics of potential response during pulse on-time depends on the adsorpti on capability of the additive and the pulse current that is applied. F or a small applied pulse current, the additive-adsorption-induced acti vation overpotential may overwhelm the concentration overpotential, an d a negative potential derivative with respect to time may occur durin g on-time. For a large applied current or with an additive of minor ad sorption capability, the normal positive potential derivative with res pect to time is expected during on-time because the concentration over potential is more influential.