Novel Polyimide Film and Use Thereof

Abstract

The present invention provides a polyimide film and its usage. The polyimide film according to the present invention does not cause dimensional change due to thermal stress. The present invention particularly relates to a polyimide film and its usage, which polyimide film has a characteristic of suppressing thermal deformation of the material in lamination of a polyimide film and a metal layer by a laminate method. The polyimide film according to the present invention has the following characteristics: (1) an inflexion point of storage modulus ranges from 270° C. to 340° C.; (2) tan δ, which is a value obtained by dividing a loss elastic modulus by a storage modulus, has a peak-top in a range of 320° C. to 410° C.; (3) a storage modulus at 380° C. ranges from 0.4 GPa to 2.0 GPa; and (4) a storage modulus α1 at the inflexion point (GPa) and a storage modulus α2 at 380° C. (GPa) satisfy: 85≧{(α1−α2)/α1}×100≧65. With these characteristics, the polyimide film gives an effect of suppressing thermal deformation of the material in lamination of a polyimide film and a metal layer by a laminate method.

Dependencies are inferred from the claim text.