| 摘要 |
PROBLEM TO BE SOLVED: To provide a small wiring board capable of high density wiring in which stripping does not take place between a nickel plating layer and solder and a mounted electronic component can be connected normally with an external electric circuit over a long term. SOLUTION: A nickel plating layer 6 and a gold plating layer 7 are formed sequentially on the surface of wiring conductors 2 arranged on an insulating substrate 1 to produce a wiring board 4. The nickel plating layer 6 contains 0.05-3 mass% of boron and has been heat treated at a temperature of 500-1200°C. When a voltage of +200 mV is applied to the wiring conductors 2 in 5% aqueous solution of sulfuric acid at 25°C, dissolving current of nickel is not higher than 10μA/mm<SP>2</SP>of the plating layer. COPYRIGHT: (C)2004,JPO |
