Glasses for display panels and photovoltaic devices

Abstract

An aluminosilicate glass having a composition consisting essentially of, as calculated in weight percent on an oxide basis, of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3-15% B 2 O 3 , 2-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, 10-25% MCSB (i.e., MgO+CaO+SrO+BaO), and SrO and BaO in combination being less than 3%.

1. A substrate for a flat panel display or photovoltaic device wherein said substrate is comprised of a flat, transparent glass exhibiting a linear coefficient of thermal expansion (CTE) over the temperature range 0-300° C. between 30-40×10 −7 /° C. and a strain point over 600° C., said glass consisting essentially of an aluminosilicate having a composition as calculated in weight percent on an oxide basis, of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3-15% B 2 O 3 , 2-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination being less than 3%. 
     
     
       2. A substrate glass in accordance with  claim 1  which is manufactured by the float process, said glass having a liquidus viscosity greater than about 50 MPa·s (500 poises). 
     
     
       3. A substrate according to  claim 2 , wherein said glass has a CTE of 32-38×10 −7 /° C. and a strain point over 650° C. 
     
     
       4. A substrate according to  claim 3 , wherein said glass has a strain point over 675° C. 
     
     
       5. A substrate according to  claim 3 , wherein the combined SrO and BaO content of said glass is less than about 1 weight percent. 
     
     
       6. A substrate according to  claim 3 , wherein said glass is essentially free of SrO and BaO. 
     
     
       7. A flat panel display comprising a substrate in accordance with  claim 1 . 
     
     
       8. A substrate according to  claim 1 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67% SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       9. A substrate according to  claim 3 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67% SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       10. A substrate according to  claim 9 , wherein said glass has a strain point over 675° C. 
     
     
       11. A substrate according to  claim 9 , wherein the combined SrO and BaO content of said glass is less than about 1 weight percent. 
     
     
       12. A substrate according to  claim 9 , wherein the glass has a weight loss less than 5.0 mg/cm 2  when immersed in 5% HCl at 95° C. for one hour. 
     
     
       13. A substrate according to  claim 1 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-64% SiO 2 , 16-19% Al 2 O 3 , greater than 6 and less than 13% B 2 O 3 , 5-11% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination being less than 3%.   14 .A glass exhibiting a linear coefficient of thermal expansion (CTE) over the temperature range 0-300° C. between 30-40×10 −7 /° C. and a strain point over 600° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis, consisting essentially of 58-70% SiO 2 , 12-22% Al 2 O 3 , 3-15% B 2 O 3 , 2-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, and SrO and BaO in combination being less than 3%.   
     
     
       15. A glass in accordance with  claim 14  which is manufactured by the float process, said glass having a liquidus viscosity greater than about 50 MPa·s (500 poises). 
     
     
       16. A glass according to  claim 14 , wherein said glass has a CTE of 32-38×10 −7 /° C. and a strain point over 650° C. 
     
     
       17. A glass according to  claim 16 , wherein said glass has a strain point over 675° C. 
     
     
       18. A photovoltaic device comprising a substrate in accordance with  claim 1 . 
     
     
       19. A substrate according to  claim 14 , wherein said glass consists essentially of a composition, as calculated in weight percent on an oxide basis, of 58-67% SiO 2 , 15-20% Al 2 O 3 , 5-13% B 2 O 3 , 5-12% CaO, 0-3% SrO, 0-3% BaO, 1-8% MgO, and SrO and BaO in combination is less than 3 wt %. 
     
     
       20. A substrate according to  claim 1 , wherein MgO+CaO+SrO+BaO is 10-25 weight percent. 
     
     
       21. A substrate according to  claim 1 , wherein MgO+CaO+SrO+BaO is 8.6-18.2 weight percent. 
     
     
       22. A glass exhibiting a density of less than  2 . 50  g/cm 3   , a linear coefficient of thermal expansion over the temperature range  0 - 300 ° C. between  30 - 40 × 10     −7   /° C. and a strain point over  600 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises:        60 . 5 - 70   %  SiO   2 ,        15 - 18 . 9   %  Al   2   O   3 ,        7 . 1 - 15   %  B   2   O   3 ,        0 - 8   %  MgO,          6 - 12   %  CaO, and          0 - 1 . 9   %  SrO.     
     
     
       23. A glass according to  claim 22  wherein the glass has a strain point over  650 ° C. 
     
     
       24. A glass exhibiting a linear coefficient of thermal expansion over the temperature range  25 - 300 ° C. between  30 - 41 . 5 × 10   −7   /° C. and a strain point over  650 ° C., said glass comprising an aluminosilicate having a composition as calculated in weight percent on an oxide basis that comprises:        60 . 2 - 70   %  SiO   2 ,        15 - 18 . 9   %  Al   2   O   3 ,        3 . 8 - 15   %  B   2   O   3 ,        0 - 8   %  MgO,          6 - 12   %  CaO, and          0 - 1 . 9   %  SrO.     
     
     
       25. A glass according to  claim 22 ,  23 , or  24  wherein the glass is essentially free of intentionally added alkali metal oxide. 
     
     
       26. A glass according to  claim 22 ,  23 , or  24  wherein the glass is manufactured by the float process. 
     
     
       27. A substrate for a flat panel display or a photovoltaic device wherein said substrate comprises a flat, transparent glass according to  claim 22 ,  23 , or  24 . 
     
     
       28. A flat panel display comprising a substrate in accordance with  claim 27 . 
     
     
       29. A photovoltaic device comprising a substrate in accordance with  claim 27 . 
     
     
       30. A aluminosilicate glass which exhibits a linear coefficient of thermal expansion over the temperature range  0 - 300 ° C. between  30 - 40 × 10   −7   /° C. and has a composition as calculated in weight percent on an oxide basis that comprises:        58 - 70   %  SiO   2 ,        15 - 18 . 9   %  Al   2   O   3 ,        7 . 1 - 15   %  B   2   O   3 ,        0 - 8   %  MgO,          6 - 12   %  CaO, and      
       
         wherein the amount, if any, of SrO, BaO, or SrO plus BaO in the glass is such that the glass exhibits a density of less than  2 . 50  g/cm 
         3  
         and a strain point of at least  650 ° C. 
       
     
     
       31. A glass according to  claim 30  wherein the glass is essentially free of intentionally added alkali metal oxide. 
     
     
       32. A glass according to  claim 30  wherein the glass is manufactured by the float process. 
     
     
       33. A substrate for a flat panel display or a photovoltaic device wherein said substrate comprises a flat, transparent glass according to  claim 30 . 
     
     
       34. A flat panel display comprising a substrate in accordance with  claim 33 . 
     
     
       35. A photovoltaic device comprising a substrate in accordance with  claim 33 .