Glass substrate and method for manufactring the same
A glass substrate chemically strengthened, includes a primary surface that has a compressive stress layer formed in an uppermost surface layer thereof. The compressive stress layer is configured to enhance strength of the glass substrate due to a compressive stress generated in the compressive stress layer. The compressive layer consists of a layer of a potassium ion concentration equal to or less than 5000 parts per million (ppm).
1. A glass substrate usable for a cover glass of a mobile terminal device to protect a display screen of the mobile terminal device, comprising:
a primary surface comprising:
a compressive stress layer formed in an uppermost surface layer thereof by chemical strengthening;
wherein the compressive stress layer contains one or more potassium ions; and
wherein the compressive stress layer is configured to enhance strength of the glass substrate due to a compressive stress generated in the compressive stress layer;
wherein the primary surface is an etched face; and
wherein the compressive stress layer consists of a layer of a potassium ion concentration more than 0 parts per million and equal to or less than 5000 parts per million; and wherein the glass substrate has a breaking load equal to or greater than 546 N, the breaking load being measured when a center of the primary surface of the glass substrate, which has a thickness of 0.5 mm, is pressed with a pressing pin in a state where a peripheral end of the glass substrate is held.
2. The glass substrate according to claim 1 ;
wherein the chemical strengthening is low-temperature chemical strengthening.
3. The glass substrate according to claim 1 ;
wherein the glass substrate is formed from molten glass by a down-draw method.
4. The glass substrate according to claim 1 , further comprising:
aluminosilicate glass that contains SiO 2 and Al 2 O 3 , and optionally at least one of Li 2 O and Na 2 O.
5. The glass substrate according to claim 4 ;
wherein the glass substrate is formed by chemically strengthening a glass substrate that contains no component of K 2 O.
6. The glass substrate according to claim 1 , further comprising:
an etched end face.
7. A glass substrate usable for a cover glass of a mobile terminal device to protect a display screen of the mobile terminal device, comprising:
a primary surface comprising:
a compressive stress layer formed in an uppermost surface layer thereof by chemical strengthening;
wherein the compressive stress layer contains one or more potassium ions; and
wherein the compressive stress layer is configured to enhance strength of the glass substrate due to a compressive stress generated in the compressive stress layer;
wherein the primary surface is an etched face;
wherein the compressive stress layer consists of a layer of a potassium ion concentration more than 0 parts per million and equal to or less than 5000 parts per million; and
wherein the glass substrate has a breaking lead load equal to or greater than 830 N, the breaking load being measured when a center of the primary surface of the glass substrate, which has a thickness of 0.7 mm, is pressed with a pressing pin in a state where a peripheral end of the glass substrate is held.
8. The glass substrate according to claim 7 ;
wherein the chemical strengthening is low-temperature chemical strengthening.
9. The glass substrate according to claim 7 ;
wherein the glass substrate is formed from molten glass by a down-draw method.
10. The glass substrate according to claim 7 , further comprising:
aluminosilicate glass that contains SiO2 and Al2O3, and optionally at least one of Li2O and Na2O.
11. The glass substrate according to claim 10 ;
wherein the glass substrate is formed by chemically strengthening a glass substrate that contains no component of K2O.
12. The glass substrate according to claim 7 , further comprising:
an etched end face.