‘One-pot’ electrochemical determination of copper and formaldehyde in electroless copper plating baths

Abstract

A simple electrochemical method has been developed for the determination of copper and formaldehyde concentrations in electroless copper plating baths. This method uses dc amperometry and anodic stripping voltammetry for the determination of formaldehyde and copper concentrations, respectively. The analyses are done sequentially using a single gold electrode in the same sample solution. The advantages of this ‘one-pot’ technique are simplicity and speed of analysis, important advantages over alternative methods of analysis which are either more time consuming, involve multiple samples, or use more elaborate instrumentation. A commercial plating bath was analysed using the described technique, yielding results which had a precision of within 5% for formaldehyde and copper. While not rigorously precise, this method can be used in process control to indicate when bath replenishment or replacement is necessary. The method can easily be implemented in plating facilities by operators using portable equipment, and an automated, on-line procedure is also possible.