The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 1998
Filed:
Oct. 03, 1996
Takashi Kohno, Yamaguchi, JP;
Akinori Otani, Yamaguchi, JP;
Toshinori Hosoma, Yamaguchi, JP;
Hiroshi Inoue, Yamaguchi, JP;
Ube Industries, Ltd., Yamaguchi, JP;
Abstract
An aromatic polyimide film in the form of a continuous tape having a thickness of 50 to 125 .mu.m favorably employed for manufacture of electric circuit is composed of a biphenyltetracarboxylic acid recurring unit and a p-phenylenediamine recurring unit. The polyimide film 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.; a heat shrinkage ratio of not higher than 0.05%; a low curling having a maximum curling of not higher than 3 mm for a disk of diameter of 86 mm; and a uniform thickness having a maximum rate of inclination of not more than 3 .mu.m per 10 mm.