| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem, where nickel of a nickel-plated layer is moved the surface of a gold-plated layer for diffusion, and the electrode of a semiconductor element cannot be connected firmly and electrically to a wiring layer. SOLUTION: A wiring board 4, where a wiring layer 2 is formed in an insulating substrate 1, is dipped into a nickel-plated bath using nickel salt and hydrazine as the metal supply source and the reduction agent, respectively, a nickel- plated layer 6 consisting of nickel particles with an average grain size of 20 nm or more is deposited onto the exposure surface of the wiring layer 2 of the wiring board 4, the wiring board 4 where the nickel-plated layer 6 is deposited is dipped into a gold-plating bath, and a gold-plated layer 7 is deposited on the surface of the nickel-plated layer 6.</p> |
