Alkaline earth aluminoborosilicate glasses for flat panel displays

• US 5,116,788 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:
  US07/743,800
• 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 is directed to the production of glass substrates for use in flat panel display devices employing polycrystalline silicon thin film transistors. The compositions for these glasses are essentially free from alkali metal oxides and consist essentially,in mole percent of:

______________________________________                                    

SiO₂ 60-65 MgO 0-4 Al₂ O₃ 8-10 SrO 0-12 B₂ O₃ 1-4 BaO 0-9 CaO 11-24 CaO + MgO + SrO + BaO 23-28 ______________________________________

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 over 675°

C., a liquidus temperature below 1125°

C., a viscosity at the liquidus temperature between 2×

10⁴ -10⁵ poises, a viscosity of 100 poises at temperatures below 1550°

C., and a weight loss of less than 1 mg/cm² after immersion for 24 hours in an aqueous 5% by weight HCl solution at 95°

C., said glass being essentially free from alkali metal oxides and consisting essentially, expressed in terms of mole percent on the oxide basis, of;

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 60-65 MgO 0-4 Al.sub.2 O.sub.3 8-10 SrO 0-12 B.sub.2 O.sub.3 1-4 BaO 0-9 CaO 11-24 CaO + MgO + SrO + BaO 23-28. ______________________________________

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

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 61- 64 MgO 0-3 Al.sub.2 O.sub.3 8-9 SrO 0-9 B.sub.2 O.sub.3 1-3 BaO 0-7 CaO 12-22 CaO + MgO + SrO + BaO 25-26. ______________________________________