METHOD FOR MANUFACTURING PRINTED-WIRING BOARD

PROBLEM TO BE SOLVED: To provide a printed-wiring board including a through-hole conductor with high density and capable of reducing a maximum diameter of a through hole.SOLUTION: A method for manufacturing a printed-wiring board comprises the steps of; laminating a first film 5A on a first resin insulation layer 2A of a core substrate 4 and a second film 5B on a second resin insulation layer 2B; forming a through hole 7 composed of a first opening 6A and a second opening 6B on the core substrate by forming the first opening 6A from a first surface of the core substrate toward a second surface by irradiating the first film with a laser beam and forming the second opening 6B from the second surface of the core substrate toward the first surface by irradiating the second film with a laser beam; removing the first film from the first resin insulation layer and the second film from the second resin insulation layer; and forming a first conductor layer 8A on the first surface of the core substrate, forming a second conductor layer 8B on the second surface, and forming a through hole conductor 9 connecting the first conductor layer and the second conductor layer in the through hole.SELECTED DRAWING: Figure 1 【課題】貫通孔の最大径を小さくすることができ、スルーホール導体を高密度に有するプリント配線板を得る。【解決手段】コア基板４の第１の樹脂絶縁層２Ａ上に第１のフィルム５Ａが積層され、第２の樹脂絶縁層２Ｂ上に第２のフィルム５Ｂが積層される工程と；第１のフィルムにレーザ光が照射されてコア基板の第１面から第２面に向けて第１の開口部６Ａが形成され、第２のフィルムにレーザ光が照射されてコア基板の第２面から第１面に向けて第２の開口部６Ｂが形成されることで、コア基板に第１の開口部と第２の開口部とからなる貫通孔７が形成される工程と；第１の樹脂絶縁層から第１のフィルムが除去され、第２の樹脂絶縁層から第２のフィルムが除去される工程と；コア基板の第１面に第１の導体層８Ａが形成され、第２面に第２の導体層８Ｂが形成され、貫通孔内に第１の導体層と第２の導体層とを接続するスルーホール導体９が形成される工程と；を備えている。【選択図】図１