GOLD DISPLACEMENT PLATING SOLUTION, AND METHOD FOR FORMATION OF JOINT PART

摘要

The present invention provides a displacement gold plating solution and a plating treatment technology capable of realizing a uniform film thickness when forming a connecting portion obtained by sequentially plating a nickel layer, a palladium layer, and a gold layer in layers. The present invention provides a displacement gold plating solution for forming a connecting portion obtained by sequentially plating a nickel layer, a palladium layer, and a gold layer in layers on a conductor layer containing a conductive metal. The displacement gold plating solution contains a gold cyanide salt, a complexing agent, and a copper compound. A molar ratio of the complexing agent and the copper compound in the displacement gold plating solution is in a range of complexing agent/copper ion=1.0 to 500. A compound formed from the complexing agent and the copper compound has a stability constant of 8.5 or higher at a pH of between 4 and 6.