| 摘要 |
PURPOSE:To obtain a wiring board excellent in the formation of an image and in its insulating quality, by etching the metallic foils at the peripheries of the hole which is formed through the chemical dissolving and the removing of its resin layer while using patterns formed on the metallic foils, and thereafter, by performing its predetermined interlayer lamination processing and its predetermined wiring formation. CONSTITUTION:Copper foil parts 11 of both the surfaces of a double-sided board 100 which are present on corresponding parts 20 of a through hole are removed therefrom by etching, and a resin layer 12 of the parts exposed by etching is dissolved by concentrated sulphuric acid. In this case, the resin layer 12 is dissolved over the wider range than the one specified by the etching parts of the copper foils, and as a result, overhanging copper foils 21 are protruded into the through hole. On the surfaces of both the protruding copper foils 21, resist patterns having the openings of about 0.7mm in their diameters whose center positions coincide with the ones of the etched holes of the copper foils whose diameters are about 0.5mm are formed respectively, and the overhanging copper foils 21 present in the opening parts are removed by etching. Further, after an alkaline permanganic acid processing, an electroless deposition and an electrolytic copper plating are applied to the through hole, and thereby, a part 26 for connecting both the surfaces of the board 100 with each other is formed. Further, wirings 27 are formed on the surfaces of the board 100 by etching, and thereby, a wiring board excelling in the formation of an image and in its insulating quality is obtained. |
