Through hole conduction structure of flexible multilayer circuit board and forming method thereof

Abstract

In case of manufacturing a flexible multilayer circuit board which comprises an internal layer circuit board which can be a cable portion and an external layer circuit board which can be a component mounting portion laminated on one side or both sides of the internal layer circuit board at a predetermined position and which has a through hole plated conduction portion 12 formed at predetermined positions of the internal layer circuit board and the external layer circuit board, surface protection layers 3 and 5 formed on external surfaces of wiring patterns 1 and 4 of the internal layer circuit board are formed in a region retreated toward the outside from a position of a through hole 13 for a through hole plated conduction portion 12.

Dependencies are inferred from the claim text.