Electrochemical Behavior of Silver Electrodeposition Using Gel Electrolyte

Abstract

Partial plating method is often applied to the fabrication of the printed wiring board by using silk-screen printing. However, the complex preprocessing and post-processing for mask pattern formation and removal are necessary in this method. In addition, a large amount of plating solution is required in the plating tank in which the substrate for electrodeposition is immersed. In order to solve these problems, Itagaki et al. 1, 2) applied the gel electrolyte as the electrolyte solution for the partial plating of copper and nickel. In this case, a little plating solution was only used for the partial plating without masking process. On the basis of the partial plating method using the gel electrolyte reported by Itagaki et al. 1), the partial plating of silver was performed in the present study. A three-electrode cell was used for the electrochemical measurement. The working electrode was the copper plate whose surface was covered with the gel electrolyte containing the silver ions. In this case, the preprocessing of copper plate was performed to remove the oxide film formed on the copper surface in the air. The counter electrode was a platinum wire. The reference electrode was a KCl-saturated silver/silver chloride electrode (SSE). The electrolyte solution was gellan gum solution containing KOH (pH=7), which was prepared from reagent grade chemicals and distilled water. All measurements were carried out by a potentiostat (Hokuto Denko, HZ-7000). The partial plating of silver was performed by a galvanostatic polarization to determine the suitable condition of electrodeposition. In addition, the potentistatic polarization measurement was carried out for investigation of electrodeposition behavior. Reference [1] M. Itagaki, K. Shimoda, K. Watanabe, K. Yasuda, J. Surf. Finish. Soc. Jpn., 54, 41 (2003). [2] M. Itagaki, I. Shitanda, W. Nakamura, K. Watanabe, Electrochim. Acta, 52, 6421 (2007).