RESIN SHEET WITH BOTH FACE-TREATED COPPER FOIL SUITABLE FOR PIERCING HOLE CARBONIC ACID GAS LASER AND ITS PRINTED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a resin sheet with an electrolytic copper foil, and its printed wiring board wherein carbonic acid gas laser irradiates directly an upside of a copper foil of a copper-clad sheet and a through hole and/or a blind via hole can be opened. SOLUTION: A resin sheet with a treated electrolytic foil on both sides is provided wherein a resin layer is provided on an opposed face of a carbonic acid gas laser-irradiated face of a both face-treated copper foil capable of being pierced by irradiating directly the irradiated face with the carbonic acid gas laser. Further, the printed wiring board is provided wherein the through hole and/or the blind via hole are prepared by irradiating directly the copper foil from above the copper foil face with the carbonic acid gas laser having sufficient energy for piercing the copper foil.