| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a polyimide film capable of reducing dimensional change of a film TD, and suitable for a substrate for a fine pitch circuit substrate such as COF capable of reducing dimensional change when processing at a high temperature.SOLUTION: The polyimide film is obtained by annealing at a temperature of not lower than 300°C and not higher than 450°C a polyimide film produced using not less than one aromatic diamine constituent selected from the group consisting of paraphenylenediamine, 4,4'-diaminodiphenyl ether, and 3,4'-diaminodiphenyl ether, and not less than one aromatic acid anhydride constituent selected from the group consisting of pyromellitic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride. The linear thermal expansion coefficientαin a machine conveying direction (MD) of the film measured under the conditions of a measuring temperature range of 50-200°C and a rate of temperature rise of 10°C/min using Shimadzu Corporation-made TMA-50 is in a range of not less than 2 ppm/°C and not greater than 10 ppm/°C, the linear thermal expansion coefficientαin a width direction (TD) measured under the aforementioned conditions is in a range of not less than -2 ppm/°C and not greater than 3.5 ppm/°C, and the relation: |α|≥|α|×2.0 is satisfied.</p> |
