| 摘要 |
PURPOSE:To enhance space factor by forming a circuit pattern through etching, removing the corner parts from the pattern through polishing, and then conducting electrolytic plating thereby forming a fine pattern. CONSTITUTION:In a flexible board comprising an insulation layer 1 applied with conductive layers (e.g. copper foil layers) on the opposite sides thereof, the conductive layers are subjected to etching to form circuit patterns 4A, 4B integrally conducting in respective surfaces. Corner parts are then removed from the circuit patterns 4A, 4B by electrolytic polishing, for example, thus producing round patterns. A through hole 5 is then made at a part each of the circuit patterns 4A, 4B. Finally, electrolytic plating is conducted to produce circuit patterns 6A, 6B. A through hole 7 is made at that time and the circuit patterns 6A, 6B are conducted electrically. This method realizes a fine pattern while enhancing the space factor. |
