Tempered glass

Abstract

This tempered glass has on a surface a compressive stress layer having compressive stress and a tensile stress layer having tensile stress inside the compressive stress layer the tempered glass beingcharacterized by satisfying formula (1) DZ / DT<0.65 (1) where DZ ([mu]m) is the zero stress depth which indicates the depth from the surface to a reference position at which stress is zero between thecompressive stress layer and the tensile stress layer and DT ([mu]m) is the alkali metal diffusion depth which indicates the depth from the surface of a regional layer in which alkali metal ions thatgenerate the compressive stress are diffused and by satisfying formula (2) CTM<73 (2) where CTM (MPa) is the maximum tensile stress.

Description

technical field [0001] The present invention relates to tempered glass, and particularly relates to tempered glass suitable for cover glasses of mobile phones, digital cameras, PDAs (portable terminals), and touch panel displays. Background technique [0002] Devices such as mobile phones (especially smartphones), digital cameras, PDAs, touch panel displays, large TVs, and non-contact power supply tend to be increasingly popular. Ion-exchange-treated tempered glass is used for these applications. In addition, in recent years, tempered glass has been increasingly used in exterior parts such as digital signage, mice, and smartphones. [0003] However, as described above, tempered glass is used for the cover glass of portable devices such as smartphones, but the cover glass may be damaged when the portable device is dropped. [0004] Such breakage of the cover glass caused by dropping may occur in various modes. For example, Patent Document 1 mentions two damage modes. One ...

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