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:
Feb. 26, 1985
Filed:
Dec. 15, 1983
Hisao Yatsuda, Sagamihara, JP;
Mutsumi Miyazaki, Sagamihara, JP;
Kabushiki Kaisha Ohara Kogaku Garasu Seizosho, Kanagawa, JP;
Abstract
According to one aspect of the invention, there is provided glass for a photomask consisting, in weight percent, of 45 to 62% SiO.sub.2, 3 to 15% B.sub.2 O.sub.3, 12 to 25% Al.sub.2 O.sub.3, 5 to 15% MgO, 0 to 5% CaO, 0 to 5% SrO, 0 to 5% BaO, 0 to 5% ZnO, 0.5 to 5% PbO, 0 to 20% La.sub.2 O.sub.3 +Gd.sub.2 O.sub.3 +Y.sub.2 O.sub.3, 0 to 1.5% Na.sub.2 O, 0 to 1.5% K.sub.2 O, 0 to 0.5% As.sub.2 O.sub.3 and 0 to 6% Sb.sub.2 O.sub.3. This glass is easy to melt and homogenize and has good resistivity to phase separation and excellent heat resisting and refractory properties, chemical durability, ultraviolet transmittance and metal vapor deposition property. According to another aspect of the invention, there is provided glass for a photomask consisting, in weight %, 45 to 60% SiO.sub.2, 0.5 to 12% B.sub.2 O.sub.3, 10 to 22% Al.sub.2 O.sub.3, 5 to 17% MgO, 0 to 5% CaO, 0 to 8% SrO, 1.5 to 15% BaO, 1.5 to 17% ZnO, 0.5 to 10% PbO, the total content of ZnO and PbO being at least 6%, 0 to 7% Ta.sub.2 O.sub.5 +Nb.sub.2 O.sub.5 +La.sub.2 O.sub.3 +Gd.sub.2 O.sub.3 +Y.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +WO.sub.3, 0 to 5% ZrO.sub.2 +TiO.sub.2, 0 to 2.5% Na.sub.2 O+K.sub.2 O+Li.sub.2 O, 0 to 0.5% As.sub.2 O.sub.3 and 0 to 0.5% Sb.sub.2 O.sub.3. This glass has the same excellent features as the first described glass and, in addition, has further improved melt properties.