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:
Sep. 19, 1989
Filed:
Jan. 29, 1988
Masaru Nikaido, Miura, JP;
Hikaru Okunoyama, Yokohama, JP;
Katsumi Yanagibashi, Yokohama, JP;
Yoshiaki Ouchi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kanagawa, JP;
Toshiba Chemical Corporation, Tokyo, JP;
Abstract
A polyamic acid is synthesized by the ring-opening poly-addition reaction using a biphenyl tetracarboxylic acid as a tetracarboxylic acid moiety and an aromatic diamine, particularly p-phenylene diamine, as a diamine moiety. An aromatic polyimide resin layer possessing a highly desirable heat-resisting property as a heat-resistant insulating coating material and excelling in adhesive strength relative to a substrate is obtained by adjusting the polyamic acid in viscosity with a suitable organic solvent, applying the resultant polyamic acid on a substrate, and firing the applied layer of the polyamic acid. The substrate, for example, is a conductor layer formed as with copper and used as a multi-layer wiring board for hybrid IC's. In a thermal head which is obtained by forming an insulating layer on a metallic substrate and superposing a multiplicity of heat-generating resistors and conductors connected severally to the heat-generating resistors on insulating layer, the aforementioned aromatic polyimide resin layer is formed on the metallic substrate. This aromatic polyimide resin layer as an insulating layer in the thermal head withstands harsh working temperature conditions and adheres strongly to the metallic substrate. Thus, it manifests various outstanding effects.