MULTILAYER FLEXIBLE WIRING BOARD

摘要

PURPOSE: To produce a highly reliable multilayer flexible wiring board having high yield. CONSTITUTION: In a flexible wiring board 10 for use in the inventive multilayer flexible wiring board 40, a metal coating 14 is formed on the surface of metal wiring 19 and exposed in a connection region. A wall member higher than the surface of the metal coating 14 is arranged on the periphery of the exposed metal coating 14. The wall member comprises a wall surface 23 of an opening 17 in a resin film 15 formed on the metal wiring 19. When a bump 34 having a solder coating 36 is abutted against the metal coating 14 in the connection region and heated at the melting point of solder metal or higher while being pressed, the solder coating 36 is fused. The fused solder metal is blocked by the wall surface 23 which prevents it from flowing out to the outer part of the connection region, bridge of soldering metal will not be formed across the metal wiring 19.