Abstract
Effects of plating conditions on utilization of sodium hypophosphite (reduction efficiency) and plating rate in caustic alkaline electroless cobalt plating baths were investigated.
Although the reduction efficiencies greatly depended upon pH of bath, type and concentration of complexing agent, and concentration of bath components, they were usually kept in the range of 30-40% under the standard plating condition.
The tartrate bath gave higher plating rates and reduction efficiencies than those of citrate bath, but it gave more variable reduction efficiencies owing to its lower stability of the bath as compared with citrate bath.
As compared with other electroless nickel plating baths having the similar compositions to that of caustic alkaline citrate bath, the cobalt plating bath gave considerably lower plating rates, but higher reduction efficiencies.
