| 摘要 |
PROBLEM TO BE SOLVED: To form a printed wiring board without using chemical solution by preparing a truncated-cone-shaped protrusion with conductive adhesive, placing semi-cured pre-preg which is slightly thinner than the entire protrusion height on a side of the protrusion with a metal foil placed outside for lamination with heat and pressure applied to form a circuit on a double-sided metal-clad laminated plate and then plating with noble metal. SOLUTION: A negative film prepared so that resist remains is put over a through hole formed part O, and etching is done to form a truncated-cone- shaped protrusion (e). In addition, 400 truncated-cone-shaped protrusions are formed also inside the semiconductor chip mounting range, silver paste (k) is attached to the protrusions, a laminated material is placed thereon and an electrolytic copper foil is placed outside for lamination, and a double-sided copper-clad laminated plate having a through hole of a metallic protrusion is formed. Thus the printed wiring board can be formed without using chemical solution. |
