| 摘要 |
PROBLEM TO BE SOLVED: To enable the formation of a considerably minute conductive portion of high density for electrically connecting wiring patterns which are formed in both sides of a substrate, and facilitates mass production of a circuit board. SOLUTION: A method comprises; forming through holes 14, by laser processing, in a substrate 10 having electric insulation properties and bonding properties; thermally pressing and bonding a metal foil 30a onto one surface of the substrate 10 having the through holes 14 for integration therewith; effecting electrolytic plating to the metal foil 30a for allowing it to serve as a plated power supply layer; filling the through holes 14 with a conductive metal 34 for welding; and thermally pressing another metal foil 30b onto the other surface of the substrate 10, while welding the conductive metal 34 filled in the through holes 14 to the metal foil 30b with the heat during the bonding of the metal foil 30b. COPYRIGHT: (C)2004,JPO |
