METHOD OF MANUFACTURING MULTILAYER WIRING BOARD AND MULTILAYER WIRING BOARD

• Main Authors: HAYASHI EIICHI, OHASHI SEIICHIRO, YAZAWA TAKAAKI, NAKAMURA SHIGEO, NAKAMURA JUNICHI
• Format: Patent
• Language: English
• Published: 19.12.2013
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer printed wiring board capable of suppressing an etchback phenomenon and projection of a glass cloth from the via hole wall surface sufficiently, and forming a highly reliable via.SOLUTION: In the method of manufacturing a multilayer printed wiring board, a via hole 5 is formed in an insulation layer 4, formed of a prepreg 3 produced by impregnating a glass cloth 1 with a thermosetting resin composition 2, by laser irradiation. The via hole 5 is then subjected to glass etching by a glass etching solution and desmearing by an oxidant solution. With such a configuration, an etchback phenomenon and excessive projection of a glass cloth from the via hole wall surface can be suppressed sufficiently, and a highly reliable via can be formed. In particular, a highly reliable via can be formed even for a small diameter via hole having a top diameter of 75 μm or less.