| 摘要 |
PURPOSE:To carry out partial silver plating at low concn., low temp. and high current density by adding a specified amount of an additive consisting of selenium oxide, acetylacetone, an alcohol, an alkali cyanide and a mercapto compound to a silver plating soln. for jet nozzle type partial silver plating. CONSTITUTION:An additive is prepd. by blending prescribed percentages of selenium dioxide, acetylacetone, an alcohol such as ethanol, an alkali cyanide such as potassium cyanide and a mercapto compound such as mercaptoimidazole and 5-50ppm of the additive is added to a silver plating soln. for jet nozzle type partial silver plating. When the resulting silver plating soln. is used, a smooth silver plated surface having satisfactory suitability to wire bonding is obtd. even by plating at about 30g/l low concn. of silver, about 40 deg.C low temp. and about 40A/dm<2> high current density.
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