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:
Apr. 15, 2003
Filed:
Aug. 09, 2001
Applicant:
Inventors:
Assignee:
DuPont-Toray Co., Ltd., Tokyo, US;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B 2/700 ; B32B 3/00 ; C08L 7/706 ;
U.S. Cl.
CPC ...
B32B 2/700 ; B32B 3/00 ; C08L 7/706 ;
Abstract
A polyimide film is produced by copolymerizing pyromellitic dianhydride in combination with phenylenediamine, methylenedianiline and 3,4′-oxydianiline in a specific molar ratio. The polyimide film, when used as a metal interconnect board substrate in flexible circuits, chip scale packages (CSP), ball grid arrays (BGA) or tape-automated bonding (TAB) tape by providing metal interconnects on the surface thereof, achieves a good balance between a high elastic modulus, a low thermal expansion coefficient, alkali etchability and film formability.