| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the source of cracking by an Ni grain boundary, and to provide a thermal-stress-proof wiring pattern by covering one or entire part of the protrusions of grinding powder of an insulator whose one part protrudes from a plating layer with a conductive film. SOLUTION: In the printed-wiring board, a substrate 1 made of resin, Cu foil 2 being applied onto the substrate for forming a desired pattern, an Ni layer 3, and an Au layer 5 are sequentially laminated. Furthermore, the Ni layer 3 contains alumina fine powder 6. Also, one part of the alumina fine powder 6 projects on the Ni layer 3. Onto the Ni layer 3 and the alumina fine powder 6, the Au layer 5 is laminated. When the Ni layer 3 is to be formed, the alumina fine powder 6 is included, thus suppressing grain boundary growth of Ni, and setting a part without the alumina powder 6 on the surface of the Ni layer 3 to a smooth surface shape. Also, to suppress the grain boundary growth, the alumina fine powder 6 of 10 to 150 g may be preferably contained into Ni plating liquid 4 of 1 litter. |
