| abstract |
The present invention relates to a flexible printed circuit having metal wiring on the surface, a CSP, a BGA or a rigid when applied to a metal wiring circuit board base material for a tape automated bonding (tape automated bonding) tape (tab tape). Provided is a polyimide mixed film that satisfies the properties and curl resistance in a balanced manner, has excellent solder resistance, and has excellent handleability in the process. SOLUTION: Based on the acid dianhydride, 10 to 40 mol% of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 60 to 90 mol% of pyromellitic dianhydride (PMDA) and at least a four-component copolymeric polyamic acid composed of 10 to 40 mol% of paraphenylenediamine (PPD) and 60 to 90 mol% of 4,4'-oxydianiline (ODA) based on diamine. A polyimide mixed film having a Young's modulus of 4 GPa or more and a heat shrinkage of less than 0.2%. [Selection diagram] None |