| 摘要 |
<p>A non-cyanide electroless gold plating solution, which can be used in an acidic region, is excellent in stability, and does not roughen the underlying layer even when an underlying layer is formed of a medium-phosphorus type Ni-P plated metal layer, and a method for electroless gold plating using the non-cyanide electroless gold plating solution are provided. In a non-cyanide electroless gold plating solution free from a cyanide compound, the non-cyanide electroless gold plating solution comprises: bis-(3-sulfopropyl)disulfide as a complex agent for gold stabilization. The electroless gold plating solution has a pH value of 7 or less. The electroless gold plating solution further comprises thallium(Tl) as a precipitation accelerator. The electroless gold plating solution receives gold from a gold source of a gold sulfite salt or a chloroaurate salt. A method for electroless gold plating comprises using the non-cyanide electroless gold plating solution as a electroless gold plating solution for dipping the substrate when forming a gold layer, by electroless gold plating, on a metal surface exposed at a bottom surface of a concave portion that is opened in a mask layer made of a resin and covered on one face of a substrate.</p> |
