| 摘要 |
PURPOSE:To prevent any trouble caused by any burr as well as any shortcircuiting between a metal core member and a circuit conductor by coating necessary parts of circuit conductor metal on both surfaces or on one surface of the same with an etching resist, drilling through-holes through the circuit conductor metal, and etching the circuit conductor metal. CONSTITUTION:Necessary parts of circuit conductor metal 3 on both surfaces or one surface of the same are coated with an etching resist 4, through-holes are drilled at necessary locations through the circuit conductor metal, and the circuit conductor metal 3 is etched. The etching is carried out selectively for a part which is not coated with the etching resist 4. This process removes any burr formed by the drilling on the circuit conductor metal 3. Hereby, a trouble caused by such burr can be eliminated together with the elimination of any shortcircuiting between a metal core member 1 and the circuit conductor 3. |
