Aromatic polyimide film and polyimide/copper foil composite sheet

A continuous aromatic polyimide film having a thickness of 50 to 125 .mu.m and comprising a biphenyltetracarboxylic acid recurring unit and a p-phenylenediamine recurring unit, which has the following characteristics:

• a tensile strength of not lower than 30 kg/mm.sup.2 ;
• a tensile modules of not lower than 500 kg/mm.sup.2 ;
• a linear expansion coefficient of not higher than 2.5.times.10.sup.-5 cm/cm/.degree.C., said linear expansion coefficient being measured while the film is heated from 50.degree. to 200.degree. C.;
• a heat shrinkage ratio of not higher than 0.05%, said heat shrinkage ratio being measured by heating the film at 200.degree. C. for 2 hours;
• a maximum curling of not higher than 3 mm, said curling being a height from the center bottom to the peripheral edge which is measured under the condition that the film having been cut to give a disk of a diameter of 86 mm is kept vertically to the horizontal plane by fixing it at its center;
• and
• a uniform thickness having a maximum rate of inclination of not more than 3 .mu.m per 10 mm, said rate of inclination being measured in the width direction of the film in the form of continuous tape.