| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyimide film capable of reducing a dimension change in a width direction (TD) of a film, and favorable for a substrate for a fine pitch circuit such as a chip-on-film (COF) using a semi-additive method.SOLUTION: The polyimide film is constituted by paraphenylenediamine, pyromellitic acid dianhydride, and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride used as principal raw materials where protrusions of a surface of the polyimide film is formed of inorganic particles having an average particle size of 0.01-1 μm, the heat expansion coefficient αof the film in a machine-conveying direction (MD) measured under the condition of a measuring range of 50-200°C and a temperature-raising rate of 10°C/min. is within a range of 2.0-10.0 ppm/°C, the heat expansion coefficient αof TD is within a range of 2.0-3.5 ppm/°C, and the relation |α|≥|α|×2.0 is satisfied.SELECTED DRAWING: None |
