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: ______________________________________ SiO 2 63-68 BaO 4.5-10
Al 2 O 3 7.5-11 CaO + SrO + BaO
14-26
CaO 9.5-16 B 2 O 3 1-7
SrO 0-5
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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 1.5×10 5 poises, and, being essentially free from alkali metal oxides and MgO, consists essentially, expressed in terms of mole percent on the oxide basis, of: ______________________________________
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.
______________________________________
Claim 2
Dependent Claim
108 words
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 1.5×10 5 poises, and, being essentially free from alkali metal oxides and MgO, consists essentially, expressed in terms of mole percent on the oxide basis, of: ______________________________________
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.
______________________________________
Claim 3
Dependent Claim
37 words
A flat panel display device according to claim 1 wherein said glass consists essentially of: ______________________________________
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.
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