| 摘要 |
PROBLEM TO BE SOLVED: To positively prevent dissolution due to the local battery reaction of a conductor circuit and to inhibit failure such as disconnection, by forming a covering layer and a roughened layer sequentially from a conductor side on the surface of a conductor circuit. SOLUTION: A roughened layer 11 is provided on the entire surface of conductor circuits 4 and a through hole 9, and a resin filler 10 is applied to both surfaces of a substrate 1 by a printing machine, thus filling the filler between the liquid circuits 4 or into the through hole 9 and curing it by heat treatment. Then, the roughened layer 11 is removed and both surfaces of the substrate are planarized by the resin filler 10, and a covering layer consisting of Cu-Ni-P alloy and the roughened layer 11 consisting of Cu-Ni-P alloy are formed on the surface on the land of the exposed conductor circuits 4 and the through hole 9 an then an Sn layer is formed on the surface, thus positively preventing solution due to the local battery reaction of the conductor circuit and improving the connection reliability between an inner-layer conductor circuit and a via hole. |
