Abstract
Compact electronic devices are created primarily using fine patterning technology. Electroless Ni-P/Au plating plays an important role in the metal finishing for these printed circuit boards. In this study, we evaluated new additives containing high-valent metal ions for electroless nickel plating to improve pattern forming. Conventional additives have caused step plating or poor corrosion resistance. But the addition of high-valent metal ions could prevent these problems. Also, our research indicates that the addition of trivalent cobalt ions could most effectively prevent deposition outside of the patterns. We suppose that cobalt reduction from trivalent to bivalent happens on palladium residues preferentially to the deposition of nickel. Therefore, deposition outside of the patterns can be prevented by the addition of trivalent cobalt ions.
