ELECTRODEPOSITION OF GOLD FROM A SULPHITE BATH BY DIRECT AND PULSE CURRENTS: APPLICATIONS TO OPTO-ELECTRONIC DEVICES

摘要

The applicability of gold electrodeposition from a sulphite electrolyte for the manufacture of opto-electronic devices has been investigated. Electrodeposition of gold has been carried out by direct and pulse currents at a rotating cylinder Hull type cell and a rectangular flow cell. The rotating cylinder Hull cell was used to determine the effect of fluid hydrodynamics, current density, and current waveform on the microstructure of gold deposits in the laboratory. Electrochemical and hydrodynamic parameters that yielded best results in laboratory experiments were then used to electrodeposit gold on wafers placed in a rectangular flow cell. It was found that the microstructure of gold was dependent on applied current density during direct current deposition, but it was dependent on steady state and non-steady state mass transfer during pulse current plating.