| abstract |
The wiring board includes an electrode made of Cu or a Cu alloy, and a plating film having an electroless nickel layer formed on the electrode and an electroless gold layer formed on the electroless nickel layer. The electroless nickel plating layer is formed by co-precipitation of Ni, P, Bi, and S, and the content of P contained in the electroless nickel plating layer is 5% by mass or more and less than 10% by mass, and the content of Bi is 1 to 1000 ppm by mass. The content of S is 1 to 2000 ppm by mass, and the mass ratio of S to the content of Bi (S/Bi) is larger than 1.0. |