ALKALI-FREE GLASS SUBSTRATE AND METHOD FOR THINNING ALKALI-FREE GLASS SUBSTRATE

摘要

The present invention relates to an alkali-free glass substrate which has been thinned down by 5 μm or more by means of hydrofluoric acid (HF) etching and has a plate thickness of 0.4 mm or less. This alkali-free glass substrate is composed of predetermined alkali-free glass, and this alkali-free glass substrate after thinning has a specific elastic modulus of 31 MNm/kg or more and a photoelastic constant of 30 nm/MPa/cm or less.