| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board with a solder pad for a lead-free solder inhibiting the generation of an air gap on a junction interface and having a high reliability on a connection. SOLUTION: The wiring board has a wiring layer, an insulating resin layer, and the solder pad for the connection by the lead-free solder with another wiring board or an IC chip. In such a wiring board, the solder pad has at least a nickel layer and a gold layer, and the gold layer is formed by a substitution/reduction type gold plating on the nickel layer. A substitution reduction radio [a reduction gold quantity/a total gold quantity=(the total gold quantity-2×the substitutional nickel quantity)/the total gold quantity] (where the reduction gold quantity: the number of gold atoms by a reduction contained in the gold layer, the total gold quantity: the number of gold atoms contained in the gold layer and the substitutional nickel quantity: the number of nickel atoms liquated out into a gold plating liquid by the substitution) in the substitution/reduction type gold plating is set in 0.6 or more in the case. COPYRIGHT: (C)2006,JPO&NCIPI
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