METAL FOIL WITH FLEXIBLE RESIN AND FLEXIBLE PRINTED WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a metal foil with a flexible resin capable of reducing thermal expansion coefficient and improving flexibility.SOLUTION: A metal foil with a flexible resin comprises a metal foil 3, a first resin layer 41 arranged on the metal foil 3 and a second resin layer 42 arranged on the first resin layer 41. The first resin layer 41 contains at least one of a polyamide-imide resin and a polyimide resin. The second resin layer 42 contains silica surface-treated by a silane coupling agent represented by general formula (A) in a range of 50 to 100 phr and is semi-cured. YSiX...(A), where X represents a methoxy group or an ethoxy group and Y represents an aliphatic long chain alkyl group having carbon atoms in a range of 6 to 18.