The Practical Method for Monitoring Additives in Copper Electroplating Baths Using the Chronopotentiometry Technique

Copper electroplating is one of the key technologies for printed circuit board production. Especially additive condition in electroplating baths for filling via holes is to be controlled more precisely. We developed the practical methods for monitoring additive condition in copper electroplating baths using the chronopotentiometry technique. Chronopotentiometry technique can be applied as the supplementary method for monitoring additive conditions. The time-potential curve is obtained by the chronopotentiometry measurement, which correlates to additive condition. We have been periodically obtaining the time-potential curves for monitoring the bath conditions of filling via holes in our FC-BGA plant since 2004. We are developing two new analysis methods to monitor additive conditions. For the both methods, time-potential curves are obtained and the analysis methods are different between the two. They are hopeful for monitoring additive condition of via hole filling to improve the analysis accuracy.