| abstract |
The object of the present invention is to provide and there is good flexibility and dimensional stability, be suitable as the polyimide film that flexible print wiring board etc. uses, and employ plywood and the metal-clad of this film.The feature of this polyimide film is, there is the multilayered structure of the coating layer comprising core layer and be exposed at film two sides outward, its core layer is the non-thermal plasticity polyimide of the average linear coefficient of expansion 5 ~ 20ppm/ DEG C at 100 ~ 200 DEG C, its coating layer is the polyimide of below stripping strength 3N/cm, film entirety average linear coefficient of expansion at 100 ~ 200 DEG C is 9 ~ 30ppm/ DEG C, and the average elastic modulus (a) of described core layer and the average elastic modulus (b) of coating layer meet following relational expression (1): a > b. |