MULTILAYER PRINTED CIRCUIT BOARD AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To manufacture a multilayer printed circuit board which has via-holes, has excellent high density interconnection wirings and has an excellent fine structure with a high efficiency by a method wherein the via-holes are formed through two or more layers continuously. SOLUTION: A thermosetting epoxy bonding film 2 is provided between an inner layer board 1 on which a conductor circuit is formed beforehand and an outer layer copper foil 3 and is cured by heat and pressure to bond the copper foil 3 and the board 1 to each other. An etching resist layer is formed on the outer layer copper foil 3 and fine holes 4 are formed in the copper foil surface by selective etching and the etching resist layer is removed. Then the parts of the cured resin layer 2 under the fine holes 4 are removed by etching with etchant composed of amide system solvent, alikaline metal compound and alcohol system solvent to form via-holes 6 and the conductor circuit formed on the inner layer board 1 is exposed and is electrically connected to the outer layer copper foil 3. An etching resist layer is formed on the outer layer copper foil 3 and a wiring circuit is formed by selective etching and the resist layer is removed. The via-holes are formed through two or more layers.