公开(公告)号：US10822264B2

公开(公告)日：2020-11-03

申请号：US15458519

申请日：2017-03-14

Applicant: AGC INC.

Inventor： Tetsushi Takiguchi ,  Shunji Inoue ,  Kazutaka Ono ,  Hirofumi Tokunaga ,  Jun Akiyama ,  Yasumasa Kato ,  Taketoshi Taniguchi

IPC: B32B9/00 ,  C03C3/091 ,  C03B17/06 ,  C03B25/08 ,  C03B18/02

Abstract: The present invention relates to an alkali-free glass substrate, in which when two arbitrary sites in one main surface thereof are selected, an absolute value of a difference between a thermal shrinkage ratio in an arbitrary direction at one site and a thermal shrinkage ratio in a direction orthogonal to the arbitrary direction at another site is 2 ppm or less, provided that the thermal shrinkage ratio is calculated by measuring a deformation amount in a measuring direction of the glass substrate between before and after a heat treatment of raising a temperature from normal temperature to 600° C. at 100° C./hour, holding the glass substrate at 600° C. for 80 minutes, and lowering the temperature from 600° C. to normal temperature at 100° C./hour.