| 摘要 |
PURPOSE:To obtain a plural-layer film excellent in electric conductivity on the surface of an article to be treated by performing successively the electroless Ni plating having a required thickness, the electroless Cu plating, the electroless Ag plating and the electroless Au plating for obtaining the electric conductivity among respective-films on the article consisting of Al(alloy) or Mg(alloy). CONSTITUTION:Oil stuck on the surface of Al(alloy) or Mg(alloy) is removed with trichlene or the like and thereafter degreased (a) with an alkaline aq. soln. composed essentially of NaOH. Successively the surface of the above- mentioned article after the degreasing is pickled (b) with an acidic aq. soln. composed essentially of HNO3 to remove a smut and thereafter Zn substitution (c) is performed by an ordinary method. After peeling (d) the above-mentioned layer (c) substituted with An with an acidic aq. soln., the second Zn substitution (e) is performed to obtain a dense crystalline grain. Then the aimed plural-layer electroless plating is performed with a comparatively simple method by performing successively the electroless Ni plating (f) having a required thickness, the electroless Cu plating (g), the electroless Ag plating (h) and athe electroless Au plating (i) on the surface of the article after the above-mentioned treatment. |
