| 摘要 |
PURPOSE:To form a thick circuit, with high positional accuracy and without a complicated process, where a large electric current can flow by a method wherein a thickness of an unnecessary part of a metal layer is reduced down to a prescribed thickness by an electric discharge machining operation and, after that, a remaining metal is melted and removed by an etching operation. CONSTITUTION:A metal layer 3 to be used as a circuit layer later is pasted on a metal sheet 1 via an insulating layer 2; a discharge electrode corresponding to a shape of a circuit to be formed is manufactured separately; this electrode is faced to the upper part of the metal layer 3; an electric discharge is started under a prescribed condition; the electric discharge is continued until a thickness capable of being etched is obtained; unnecessary metal is removed. After that, the circuit part is protected by an etching resist; remaining metal (a) is etched and removed; a circuit layer 10 is formed. Thereby, it is possible to form a circuit of a film thickness, with good accuracy, where a large electric current can flow. |
