High alumina, alkaline earth borosilicate glasses for flat panel displays

• US 5,116,787 A
• Filed: 08/12/1991
• Issued: 05/26/1992
• Est. Priority Date: 08/12/1991
• Status: Expired due to Term

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Dumbaugh, William H. Jr.
• Primary Examiner(s): BELL, MARK LEE
• Application Number:
  US07/743,799
• Time in Patent Office: 288 Days
• Field of Search: 501/66, 501/69, 340/719, 359/82
• US Class Current: 501/66
• CPC Class Codes: C03C 3/091 containing aluminium

Abstract

This invention relates to glasses for use as substrates in flat panel display devices which use polycrystalline silicon thin film transistors. The compositions for those glasses are essentially free from alkali metal oxides and MgO and consist essentially, in weight percent, of:

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SiO₂ 63-68 BaO 4.5-10 Al₂ O₃ 7.5-11 CaO + SrO + BaO 14-26 CaO 9.5-16 B₂ O₃ 1-7 SrO 0-5 ______________________________________

Claims

1. In a flat panel display device containing a flat, transparent glass substrate carrying polycrystalline silicon thin film transistors, the improvement wherein said glass exhibits a strain point of 655°

C. or greater, a liquidus temperature below 1075°

C., a long term stability against devitrification when in contact with platinum and high temperature refractory ceramic materials, a liquidus viscosity greater than 1.5×

10⁵ poises, and, being essentially free from alkali metal oxides and MgO, consists essentially, expressed in terms of mole percent on the oxide basis, of;

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 63-68 BaO 4.5-10 Al.sub.2 O.sub.3 7.5-11 CaO + SrO + BaO 14-26 CaO 9.5-16 B.sub.2 O.sub.3 1-7 SrO 0-5. ______________________________________

2. A flat panel display device according to claim 1 wherein said glass consists essentially of:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 64-66 BaO 4.5-8 Al.sub.2 O.sub.3 8-10 CaO + SrO + BaO 18-24 CaO 10-15 B.sub.2 O.sub.3 2-6 SrO 0-3. ______________________________________