Flexible base materials, their preparation and their use for printed circuits

摘要

Flexible base materials consisting of a metal foil and a film, firmly adhering thereto without an interlayer, of a polyamide/polyimide block copolymer of the formula I, or of a polyamide/polyimide copolymer prepared from a polyamide acid block of the formula IVa or Va and a dicarboxylic acid dichloride of the formula XI and a diamine of the formula XII. The individual symbols are defined in claim 1. The base materials according to the invention are suitable for the preparation of flexible printed circuits.