In Situ Electrochemical Technique for Monitoring the Activity of Electroless Plating Baths
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
The instantaneous plating rate or activity of an electroless plating bath can be measured in situ by monitoring the polarization resistance of the bath. Into an electroless plating bath, or, optionally, into a side bath flow through, a counter electrode, a reference electrode and a rotating disk electrode are inserted. A scanning triangle waveform is then applied to the rotating disc electrode in incremental steps. The current generated by the bath is then measured. At the mixed potential (cathodic reaction current exactly compensated by anodic reaction), the plating current is generated and the voltage is a constant equal to the scan rate. At the same mixed potential, the polarization resistance is then inversely proportional to the time derivative of the current only.