| 摘要 |
PROBLEM TO BE SOLVED: To prevent exfoliation of conductor circuits from layer-insulating resin layers on a board by causing the insulating resin layers to contain a reactant of a bifunctional (meth)acrylic ester monomer, in a ratio within a specific range with respect to the whole solid component of the insulating resin layers. SOLUTION: By laminating sheets of copper foil on both surfaces of a board 1, boring a hole in the board 1 with a drill, subjecting to electroless plating and etching into patterns, lower-layer conductor circuits 4 along with a through- hole 9 are formed on both surfaces of the board 1. In all the surfaces of the conductor circuits 4 which includes the through-hole 9, roughened surfaces 4a, 9a are formed. The conductor circuits 4 and through-hole 9 are filled up with a resin filler 10. The filler 10 is heated and dried, and insulating resin layers 2 are formed. These insulating layers 2 are caused to contain a reactant of a bifunctional (meth)acrylic ester monomer in a ratio of 5-15 wt.% with respect to the whole solid components of the insulating layers 2. |
