Substitution-type electroless gold plating solution containing purine or pyrimidine-based compound having carbonyl oxygen and substitution-type electroless gold plating method using the same

Abstract

A substitution gold plating solution for performing uniform gold plating directly on copper wiring of a printed circuit board is provided and a gold plating method using the same is provided, the solution comprising a purine-based compound or a pyrimidine-based compound having a carbonyl oxygen used as a localized corrosion inhibitor, a water-soluble gold compound, an aminocarboxylic acid as a complexing agent, a dicarboxylic acid as a conductivity improving agent, an α-hydroxycarboxylic acid and heteroaryl carboxylic acid as a base metal elution and reprecipitation preventing agent, a sulfite compound as a gold ion stabilizer, an axole compound as a surface corrosion inhibitor, other surfactants, crystal regulators, pH adjuster, and buffers. The substitution-type electroless gold plating solution according to the present invention prevents the localized corrosion of the copper surface, which is the base metal, and thus the gold plating film produced is excellent in solder mounting reliability.