EFFECT OF CU(OH)(2) ON ELECTROLESS COPPER PLATING

Although electroless copper deposition has been widely used in the ele ctronic industry, the selection of the bath solutions relies still on some empirical rules. This paper provides a further exploration of the bath compositions for electroless copper plating. It was found that t he formation of Cu2O in electroless copper plating is associated with the presence of Cu(OH)(2) in the bath. A chemical equilibrium calculat ion was thus made for the avoidance of Cu(OH)(2) in an electroless cop per bath. Sodium thiosulfate was found to be an effective stabilizer f or electroless copper plating. The plating was further optimized based on a statistical design of sorts, namely, Taguchi's approach. Effects of individual components on the plating rate were discussed.