| 摘要 |
A wiring substrate (1) includes an electrode (12) including Cu or a Cu alloy, and a plated film (14) including an electroless nickel-plated layer (18) formed on the electrode (12) and an electroless gold-plated layer (22) formed on the electroless nickel-plated layer (18). The electroless nickel-plated layer (18) is formed by co-precipitation of Ni, P, Bi, and S, the electroless nickel-plated layer (18) includes a content of P of 5% by mass or more and less than 10% by mass, a content of Bi of 1 ppm by mass to 1,000 ppm by mass, and a content of S of 1 ppm by mass to 2,000 ppm by mass, and a mass ratio of the content of S to the content of Bi (S/Bi) is more than 1.0. |
