The invention relates to the field of advanced packaging
semiconductor driving chips, and discloses a gold
etching solution, application thereof and a method for
electroplating gold-silver
alloy on an etched
wafer. The gold
etching liquid comprises a complexing agent, an
oxidizing agent, an aluminum protective agent and a
solvent; wherein the complexing agent comprises a main complexing agent and an auxiliary complexing agent; the main complexing agent is selected from
thiourea and / or
thiourea derivatives; the auxiliary complexing agent is selected from at least one of butyl
xanthate, isoamyl
xanthate, thionocarbamate and diethyl
phosphonate; the weight ratio of the complexing agent to the
oxidizing agent to the aluminum protective agent to the
solvent is 1: (0.2-1.5): (0.2-1.5): (20-30). The gold
etching liquid has mild oxidability, can selectively etch a PVD gold seed layer, avoids etching a gold-silver
alloy bump, does not cause serious deformation of the gold-silver
alloy bump, avoids damage of etching to an aluminum circuit in a
wafer, and is mild in etching condition and adjustable in gold
etching rate.