| 摘要 |
PROBLEM TO BE SOLVED: To attain high density wiring having inter-layer connection with high reliability, and to mount the wiring on the printed circuit board. SOLUTION: Projecting conductive bumps 2 are provided to form an inter- layer connection part to a prescribed position of a side of a copper foil 1 without a metallic oxide layer. A copper foil 1' without an oxide layer is sequentially overlapped and laminated onto areas, corresponding to an insulating synthetic resin sheet 3 and at least the conducive bumps 2 at the side where the conductive bumps 2 are formed. There, the laminator is pressed, the tips of the projecting conductive bumps 2 are inserted through the synthetic resin sheet 3 and opposite to the copper foil 1' to form a copper foil clad lamination board, and the copper foils 1, 1' of the copper foil clad lamination board are selectively etch-processed to form a required pattern. |
