Hard gold-based plating solution

Abstract

To provide a hard gold-based plating solution which enables selective partial plating treatment and is suitable for electronic components such as a connector. A hard gold-based plating solution of the present invention comprises: a soluble gold salt or a gold complex; a conductive salt; and a chelating agent, wherein the hard gold-based plating solution further comprises an aromatic compound having one or more nitro groups, for example, an aromatic compound selected from the group consisting of nitrobenzoic acid, dinitrobenzoic acid and nitrobenzene sulfonic acid. The hard gold-based plating solution further comprises at least one metal salt of a cobalt salt, a nickel salt and a silver salt, or polyethyleneimine as an organic additive.

1 . A hard gold-based plating solution comprising: a soluble gold salt or a gold complex; a conductive salt; and a chelating agent, wherein the hard gold-based plating solution further comprises an aromatic compound having one or more nitro groups. 
     
     
         2 . The hard gold-based plating solution according to  claim 1 , wherein the hard gold-based plating solution further comprises at least one metal salt of a cobalt salt, a nickel salt and a silver salt. 
     
     
         3 . The hard gold-based plating solution according to  claim 1 , wherein the hard gold-based plating solution further comprises polyethyleneimine as an organic additive. 
     
     
         4 . The hard gold-based plating solution according to  claim 1 , wherein the aromatic compound is selected from nitrobenzoic acid, dinitrobenzoic acid and nitrobenzene sulfonic acid. 
     
     
         5 . The hard gold-based plating solution according to  claim 2 , wherein the aromatic compound is selected from nitrobenzoic acid, dinitrobenzoic acid and nitrobenzene sulfonic acid. 
     
     
         6 . The hard gold-based plating solution according to  claim 3 , wherein the aromatic compound is selected from nitrobenzoic acid, dinitrobenzoic acid and nitrobenzene sulfonic acid.