State estimation and bath control for the electroless nickel-plating process

A mixed-potential model is proposed for the electroless nickel-plating process. It is tested against measured data and used for monitoring of the thickness and phosphorous content of plating film. The bath-loading process with strong effect on chemical reactions is evaluated as Markov pure jump process and applied in control. The thickness and phosphorous content are stabilized at desired levels using electrochemically balanced tracking trajectory for pH-index and nickel concentration. The latter processes are controlled at the balanced trajectory using the precise controls developed.