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:
Nov. 12, 2002
Filed:
Dec. 11, 2000
Takahiro Fukuoka, Osaka, JP;
Amane Mochizuki, Osaka, JP;
Naoki Kurata, Osaka, JP;
Naotaka Kinjo, Osaka, JP;
Toshihiko Omote, Osaka, JP;
Nitto Denko Corporation, Osaka, JP;
Abstract
The polyamic acid of the invention can be obtained by the reaction of an acid anhydride component comprising pyromellitic anhydride and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane with 2,2′-di-substituted-4,4′-diaminobiphenyls as a first aromatic diamine and any aromatic diamine component, as a second aromatic diamine, of 2,2-bis(4-aminophenoxyphenyl)propanes, 1,1-bis(4-(4-aminophenoxy)-3-t-butyl-6-methylphenyl)butane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane and &agr;,&agr;′-bis(4-aminophenyl)diisopropylbenzenes in an organic solvent. The polyimide resin of the invention can be obtained by heating such a polyamic acid solution. In the production of a circuit board, by using a photosensitive polyamic acid having a sensitizer incorporated in such a polyamic acid solution, a patterned polyimide resin layer can be provided as an insulation layer on a metal foil.