Patent ID: 9299869
Filing Date: 2016-03-29
CPC Classification: C03C,G06F,H01L,Y02E,Y10T

Claim Text:
1. A tempered glass substrate, which has a compression stress layer on a surface thereof, and has a glass composition comprising, in terms of mass %, 58.4 to 71% of SiO 2 , 3 to 23% of Al 2 O 3 , 0 to 1% of Li 2 O, 8.2 to 20% of Na 2 O, 0 to 2% of K 2 O, 0.5% or less of TiO 2 , and 0 to 4% of MgO+CaO+SrO+BaO, wherein the compression stress layer has a compression stress value of 600 MPa or more, and wherein the tempered glass substrate has an unpolished surface having an average surface roughness Ra of 5 Å or less.