Patent ID: 8236717

Claim:
A glass plate for a substrate, which comprises, as a glass matrix composition as represented by mass % based on oxide: SiO 2 70 to 80, Al 2 O 3 0.1 to 5, B 2 O 3 0 to 3, MgO 9.5 to 12, CaO + SrO + BaO 0 to 2, and Na 2 O + K 2 O 12.5 to 15.5, has a density of at most 2.5 g/cm 3 , has an average coefficient of thermal expansion from 50 to 350° C. of more than 75×10 −7 /° C. and at most 87×10 −7 /° C., has a glass transition point of at least 560° C., has a brittleness of at most 6.5 μm− 1/2 , and has a heat shrinkage (C) of at most 20 ppm.