Electrochemical Research of a Stable Electroless Silver Bath. Issue 3 (7th January 2016)

• Record Type: Journal Article
• Authors: Chang, Chun; Lei, Zhanwu; Li, Yuhan; Wang, Zenglin
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 3(2016)
• Page Start: D121
• Page End: D125
• Publication Date: 2016-01-07
• Subjects: additives -- electroless silver plating -- linear sweep voltammetry -- stability; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1101603jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Though electroless silver plating is used in many processes, a stable and practical electroless silver bath has been not reported. In this paper, Na2 EDTA and ethylenediamine (EN) as mixture complexing agents to improve the stability of the electroless silver bath were investigated by linear sweep voltammetry (LSV), and the composition of Ag + -EN-EDTA complex in electroless silver solution was determined. We found that the deposition rate of the bath increased with an increased pH, and the changed tendency of the deposition rate with pH agreed significantly with the tendency of the reduction peak current with pH. The results indicated in-depth that the deposition mechanism of electroless silver proposed base on the mixed potential theory of electroless deposition was credible. Further, the synergy effect of 2, 2 ′ -dipyridyl (dipy) and bromohexadecyl pyridine (bhpy) for the deposition rate and the surface morphology of Ag film was found. With an addition of dipy and bhpy, not only was the stability of the electroless silver bath be enhanced, but also the surface morphology of as-deposited silver film was improved, and a smooth and uniform silver film was achieved. Finally, a stable electroless silver bath with a high deposition rate was obtained.