| 摘要 |
PURPOSE:To restrain the side wall of a circuit pattern from sagging at etching by a method wherein a substantial etching thickness is made small without making a finished circuit pattern small in thickness when the circuit pattern is formed on a board by etching a conductive metal such as copper or the like from one side. CONSTITUTION:Resist is applied onto a copper foil 12. Two kinds of resist are applied in lamination as the resist is dissolved to remove in an after process. A resist A and a resist B denote an upper resist 16 and a lower resist 18 respectively. The resist applied copper foil 12 is exposed to light from the upside of the resist A to remove the resist A and the resist B applied on the part which is left as a circuit pattern. A copper plating is performed onto the copper foil 12 to heap copper plating layers 20 onto the parts where the resist is partly removed. The thickness of the copper plating layers 20 is similar to the resist. Only the resist A is removed off. Then, a protective plating is performed on the copper plating 20. The protective plating film 22 covers all the top and side surfaces of the copper plating layer 20 exposed to the outside. Then, the resist B is removed, and the copper foil 12 is etched using an etchant. And, the protective plating film 22 is removed. |
