In-Situ Technique for Simultaneous Monitoring of Critical Components in Plating Baths
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Simultaneous monitoring of the concentrations of multiple plating bath components can be made in the bath directly with a single measurement by using a rotating disc electrode and differential pulse voltammetry. With this monitor, a potential is applied to the rotating disk electrode in a series of small, constant amplitude pulses of short duration on a normal DC voltage ramp. The pulse heights are generally between 10 and 100 mV, and in a given measurement are the same with respect to the base potential. Two current samples are taken for each pair of potential pulses. One is taken at time t, immediately prior to the pulse, and the other is taken at time tl, just before the pulse is ended. Differential pulse voltammetry (DPV) is then used to measure the current difference.