MANUFACTURING METHOD OF PRINTED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a printed wiring board in which scattered pieces of copper can be securely removed without excessively etching a copper layer of an inner layer disposed at a via bottom nor a copper layer surface on the side of a multilayer stacked plate surface when vias are formed in a multilayer stacked plate by direct laser machining. SOLUTION: In the manufacturing method of the printed wiring board in which the vias are formed by irradiating a copper 7 or copper alloy surface of an outer most layer of the multilayer stacked plate with laser light, etching liquid 21 which is etching liquid of 3 to 5 in ratio of an etching speed of spray processing and an etching speed of dip processing and contains sulphuric acid and hydrogen peroxide is brought into contact with the copper 7 or copper alloy surface of the outermost layer through the spray processing after the laser light irradiation. COPYRIGHT: (C)2009,JPO&INPIT