| abstract |
[Summary] n [Problems] Provision of a polyimide film superior in heat resistance, rigidity and high frequency property, which is free of inconveniences due to curling even when various functional layers are laminated with heating, and which is preferable as a substrate film superior in thermal degradation stability for electronic parts. [Solving Means] A polyimide film having a planar orientation coefficient of 0.79-0.89 as measured by an X-ray diffraction method, a difference in the surface planar orientation degree between one surface thereof and the other surface thereof of not more than 2 and a curling degree of not more than 5%, which is obtained by imidation of a polyimide precursor film having a particular imidation rate. |