Method for On-Line Removal of Gold (Iii) From Gold (I) Plating Solutions
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Gold plating is of critical importance to the electronics industry. Gold is corrosion resistant and has a low contact resistance. Use of thin, plated gold films minimizes the expense of device fabrication requiring these properties; however too thin a film will be porous, while too thick a film wastes resources. Control of plated gold film thickness is usually carried out by monitoring the plating time and current density to determine total charge plated per unit area. This method assumes gold exists in the plating solution as the monovalent (Au(I)) species. In reality, trivalent gold ions (Au(III)) are often formed during electroplating by oxidation of Au(I) at the anode of the plating cell.