METHOD FOR FORMING HOLE BY LASER

摘要

PROBLEM TO BE SOLVED: To improve the reliability of blind via holes/through holes by directly irradiating the surface of a copper clad board to which general copper foil is stuck with carbon dioxide laser beams and piercing holes without polluting the surface layer. SOLUTION: Thin copper foil provided with a carrier metallic foil and having≤5μm general thickness is used as the copper foil of the copper clad board having at least two copper layers and the surface of the carrier metallic foil is directly irradiated with carbon dioxide laser beams to form blind via holes and/or through holes. Since the holes can be formed by directly irradiating the surface of the metallic foil with carbon dioxide laser beams without treating the surface of the copper foil, the carrier metallic foil prevents the pollution of the copper foil and highly reliable blind via holes and/or through holes having fine hole shapes can be quickly pierced without generating defects at the time of forming a pattern, a high-density printed board whose economic efficiency is improved can be obtained. COPYRIGHT: (C)2005,JPO&NCIPI