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:
Jul. 05, 1983
Filed:
Feb. 24, 1982
Applicant:
Inventors:
Kenji Nakagawa, Tokorozawa, JP;
Isao Masuda, Tokyo, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C / ;
U.S. Cl.
CPC ...
501 62 ; 313480 ; 501 57 ;
Abstract
An alkali-free glass composition for a photoetching mask is described, which comprises, all by mol, 55 to 65% SiO.sub.2, 7 to 11% Al.sub.2 O.sub.3, 1 to 11% PbO, 7 to 20% CaO, 3 to 13% MgO, 3 to 13% ZnO, 0 to 3% ZrO.sub.2, 0 to 3% F.sub.2, 0 to 5% As.sub.2 O.sub.3, and 0 to 5% Sb.sub.2 O.sub.3. This glass is free from defects such as pinholes, has a relatively low coefficient of thermal expansion and contains no air bubbles, and a photoetching mask composed of the glass composition.