| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a multilayer board which is satisfactory in productivity and advantageous in forming complicated circuits and hardly makes defects, even in connection vias passing through many conductor layers. SOLUTION: A one-side Cu-lined insulating material film 19 is pasted onto a conductor layer C2, an insulation layer W1 and a Cu foil 18 forming a part of a conductor layer C3 are laminated thereon, the Cu foil 18 is photo-etched to bore openings 20-1, 20-2 at via-forming regions between inner conductor layers C1, C2, insulation layers r1,3, W1 are chemically etched to bore holes 21-1, 21-2 for vias reaching the conductor layers C1, C2, Cu plating is applied to form a Cu plating layer 22 on the surface of the Cu foil 18 and the inner walls of the holes 21-1, 21-2, and the Cu foil 18 and the Cu plating layer 22 are integrated to form a conductor layer C3, together with two blind vias 23-1, 23-2 formed between the conductor layer 3 and the conductor layers C1, C2. |
