Abstract: An aromatic polyimide film favorably employable for the chip-on-film (COF) system is composed of a polyimide derived from 3,3?,4,4?-biphenyltetracarboxylic acid dianhydride and p-phenylenediamine and a powdery inorganic filler, in which the film has a thickness in the range of 25 to 35 ?m and does not have protrusions of 1 ?m or higher, and the filler has a mean diameter of less than 1 ?m.

Abstract: An aromatic polyimide film favorably employable for the chip-on-film (COF) system is composed of a polyimide derived from 3,3?,4,4?-biphenyltetracarboxylic acid dianhydride and p-phenylenediamine and a powdery inorganic filler, in which the film has a thickness in the range of 25 to 35 ?m and does not have protrusions of 1 ?m or higher, and the filler has a mean diameter of less than 1 ?m.

Abstract: A metal film/aromatic polyimide film laminate is composed of a composite aromatic polyimide film and a metal film, in which the composite aromatic polyimide film is composed of an aromatic polyimide substrate film having a linear expansion coefficient of 5×10−6 to 30×10−6 cm/cm/° C. in the temperature range of 50-200° C. (measured in machine direction), and a thin aromatic polyimide layer of polyimide prepared from a carboxylic acid component comprising a mixture of 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 2,3,3′,4′-biphenyltetracarboxylic dianhydride in a molar ratio of 50:50 to 90:10 and an aromatic diamine component composed of 1,3-bis(4-aminophenoxy)benzene or a mixture of 1,3-bis(4-aminophenoxy)benzene and p-phenylenediamine and/or diaminodiphenyl ether in a molar ratio of 10/90 or more. Tg of the thin polyimide layer is 210-310° C. The metal film is fixed to the thin polyimide layer at a 90° peel resistance of 0.

Abstract: A metal film/aromatic polyimide film laminate is composed of a composite aromatic polyimide film and a metal film, in which the composite aromatic polyimide film is composed of an aromatic polyimide substrate film having a linear expansion coefficient of 5×10−6 to 30×10−6 cm/cm/° C. in the temperature range of 50-200° C. (measured in machine direction), and a thin aromatic polyimide layer of polyimide prepared from a carboxylic acid component comprising a mixture of 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 2,3,3′,4′-biphenyltetracarboxylic dianhydride in a molar ratio of 50:50 to 90:10 and an aromatic diamine component composed of 1,3-bis(4-aminophenoxy)benzene or a mixture of 1,3-bis(4-aminophenoxy)benzene and p-phenylenediamine and/or diaminodiphenyl ether in a molar ratio of 10/90 or more. Tg of the thin polyimide layer is 210-310° C. The metal film is fixed to the thin polyimide layer at a 90° peel resistance of 0.