Patent ID: 7709406

Claim:
An alkali metal-free glass comprising in mole percent on an oxide basis: SiO 2 67.0-70.0 B 2 O 3 8.0-11.0 Al 2 O 3 9.5-12.0 MgO <3.7 CaO 5.5-11.2 SrO ≦2.2 BaO ≦2.2 MgO/CaO ≦0.7 wherein: (a) 1.0≦Σ(MgO+CaO+SrO+BaO)/(Al 2 O 3 )≦1.25, where Al 2 O 3 , MgO, CaO, SrO, and BaO represent the mole percents of the representative oxide components; (b) 2.5 MgO+5 CaO+6 SrO+7 BaO≦59; (c) the glass has a coefficient of thermal expansion less than or equal to 36×10 −7 /° C. over the temperature range of 0 to 300° C.; (d) the glass has a density less than or equal to 2.46 g/cc; (e) the glass has a liquidus temperature minus softening point up to 200° C.; and (f) the glass comprises at most 0.05 mole percent of As 2 O 3 and at most 0.05 mole percent of Sb 2 O 3 .