| 摘要 |
PURPOSE:To increase mechanical strength without increasing the total thickness, by holding a thin insulating layer of a bonding agent by flat metal spiral coils on both sides thereof so that the coils face to each other, connecting the inner ends of the coils by piercing the thin layer, and obtaining the sheet coil, with more than half of the facing metallic conductors on the top and bottom sides being overlapped. CONSTITUTION:Two sheets of thin plates comprising copper and the like which are to become coil conductors are stuck by using the thin insulating film 15 such as epoxy resin and polyester resin having excellent bonding property and electric insulating property. Photoetching is performed on both surfaces of the thin plates, and coil patterns are formed on said plates. That is, the coil conductors 21 are arranged on the top surface of the thin plate 15, with gap parts 23 being provided. The conductors 22 are arranged on the bottom surface with the gap parts 24 being provided. The inner ends of said coils are connected by piercing the thin plate 15. In this constitution, the gaps 23 and 24 are displaced so that they do not agree when viewed from the top and more than half of the top side coil and that of the bottom side coil are overlapped. |
