| abstract |
An aromatic polyimide film composed of a biphenyltetracarboxylic acid unit and a phenylenediamine unit, and having a thickness of 5-150 mum and an elongation of 45-90% shows, in combination with an electroconductive film, improved mechanical characteristics, when it has the following tensile modulus and a tear resistance measured by Elmendorf tearing tester:a tensile modulus of 750-1,300 kg/mm2 and a tear resistance of 350-1,500 g/mm in the case that the thickness is 50 mum or less;a tensile modulus of 650-1,200 kg/mm2 and a tear resistance of 550-1,500 g/mm in the case that the thickness is 50-100 mum; anda tensile modulus of 550-1,100 kg/mm2 and a tear resistance of 550-1,500 g/mm in the case that the thickness is 100 mum or more. |