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:
Mar. 31, 1992
Filed:
Dec. 06, 1990
Hatsuyuki Tanaka, Chigasaki, JP;
Hidekatsu Kohara, Chigasaki, JP;
Toshimasa Nakayama, Hiratsuka, JP;
Tokyo Ohka Kobyo Co., Ltd., Kanagawa, JP;
Abstract
A proposal is made for the use of an alkyl pyruvate or a solvent mixture mainly composed thereof as a solvent in a positive-working photoresist composition comprising an alkali-soluble novolac resin as the film-forming ingredient and a quinone diazide group-containing compound as the photosensitive ingredient. By virtue of the use of the unique solvent, the photoresist composition is advantageous in the outstandingly high stability with little moisture absorption from ambience not to cause precipitation of solid matters in addition to the quite satisfactory properties in other respects as a photoresist composition.