ADHESIVE SHEET WITH BASE USED FOR FLEXIBLE PRINTED CIRCUIT BOARD, METHOD FOR PRODUCING SAME, MULTILAYER FLEXIBLE PRINTED CIRCUIT BOARD, AND RIGID-FLEX PRINTED CIRCUIT BOARD

摘要

Disclosed is an easily processable adhesive sheet with a base which is used for flexible printed circuit boards. This adhesive sheet is prevented from dropping resin composition particles during processing of a multilayer flexible printed circuit board or a rigid-flex printed circuit board, while having high rigidity and excellent formability. The adhesive sheet is used for bonding of a flexible printed circuit board made of a polyimide resin, and is composed of a woven or nonwoven fabric base and a resin composition. The resin composition contains an epoxy resin (a) having two or more epoxy groups in a molecule, a polycarbodiimide resin (b) dispersible in a common solvent in which the epoxy resin component (a) is also dispersible and having a number average molecular weight of not less than 2,000 and less than 10,000, and an imidazole curing agent (c) as essential ingredients. The mass ratio between the component (a) and the component (b) is within the range from 80:20 to 20:80.