To securely and electrically connect a via and second wiring in a multilayer wiring board, where first wiring and second wiring whose width and area are larger than first wiring are formed on the same layer, a via hole is formed in a resin member on second wiring by press working, using a metallic mold and a via is made in the via hole and in the manufacturing method of the board.
An electrical connection projection 53 is integrally formed in a second wiring groove, whose width and area are larger than a first wiring groove with the resin member 44. First wiring 51 is formed in the first wiring groove and a second wiring 52 in the second wiring groove. A plating film 47 of a conductive metal is installed in the electrical connection projection 53, and the via 58 and second wiring 52 are connected electrically.
TANAKA MASATO
YAMAZAKI KATSUMI
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