SURFACE-TREATED COPPER-CLAD SHEET SUITABLE FOR CARBON DIOXIDE LASER PERFORATION, AND PRINTED WIRING BOARD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment layer which is not peeled off even if it is rubbed a little and to which through-holes and/or blind via holes can be formed by the direct irradiation with carbon dioxide laser, on a copper foil and to obtain a high density printed wiring board using the same. SOLUTION: Metal plating for enhancing the absorption of carbon dioxide laser is applied to the surface layer of a copper-clad sheet having an insulating layer comprising a thermosetting resin composition and the metal plating layer is heated to be alloyed to obtain the copper-clad sheet suitable for carbon dioxide laser perforation. The high density printed wiring board is obtained using this copper-clad sheet. The alloying treatment applied copper-clad sheet to which through-holes and/or blind viaholes can be formed by the direct irradiation with carbon dioxide laser is obtained and the high density printed wiring board can be efficiently formed in reduced percent defective.