S-shaped stress profiles and methods of making

Patent metadata

Field	Value
Publication number	US-12071369-B2
Application number	US-202318105040-A
Country	US
Kind code	B2
Filing date	Feb 2, 2023
Priority date	Dec 8, 2015
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A strengthened glass having a stress profile that differs from error-function and parabolic profiles. Stress relaxation and thermal annealing/diffusion effects, which occur at longer ion exchange and/or anneal times increase the depth of compression of the surface layer. A method of achieving these effects is also provided.

First claim

The invention claimed is:

1. A glass article, comprising:
opposing first and second surfaces defining a thickness t;
a center located at t/2;
a stress profile comprising:
a compressive region extending from the first surface to a depth of compression (DOC);
a maximum compressive stress (CS) within the compressive region;
a first region of the compressive region extending from the first surface to a depth d 1 , wherein d 1 >0.06t, and at least a portion of the first region has a first slope m 1 ;
a second region of the compressive region extending from d 1 to the DOC, and having a second slope m 2 , wherein |m 1 |≤|m 2 |;
a first region sub-region including an entire compressive stress spike extending from the first surface to a depth d 2 that is located at a spike compressive stress, and comprising a third slope m 3 , wherein d 2 <d 1 , and |m 1 |<|m 3 |; and
a compressive region sub-region within the compressive region having a negative curvature;
wherein the spike compressive stress at d 2 is in a range from greater than or equal to 150 MPa to less than or equal to 180 MPa.

2. The glass article of claim 1 , wherein the DOC is in a range from about 0.14t to about 0.35t.

3. The glass article of claim 1 , wherein the DOC is greater than or equal to 90 μm.

4. The glass article of claim 1 , wherein 30 MPa/μm≤|m 3 |≤200 MPa/μm.

5. The glass article of claim 1 , wherein the CS in a range from about 500 MPa to about 2,000 MPa.

6. The glass article of claim 1 , wherein a maximum absolute value of the negative curvature is at d 1 .

7. The glass article of claim 1 , wherein a maximum absolute value of the negative curvature is between 20 MPa/(t(mm)) 2 and 4,000 MPa/(t(mm)) 2 .

8. The glass article of claim 1 , wherein a slope of the stress profile at d 1 is zero.

9. The glass article of claim 1 , wherein d 2 is less than or equal to 15 μm.

10. The glass article of claim 1 having a planar configuration, wherein t is in a range from about 0.1 mm to about 1 mm.

11. The glass article of claim 1 , wherein the negative curvature has an absolute value exceeding 10 MPa/(t(mm)) 2 over a spatial extent ranging from about 2% to about 25% of t.

12. The glass article of claim 1 , wherein the maximum compressive stress CS is at the first surface, and at a depth of less than about 8 μm below the first surface a compressive stress of the article decreases to less than 50% of the maximum compressive stress CS.

13. The glass article of claim 1 , further comprising a physical center tension in a range from about 40 MPa/(t(mm)) 1/2 to about 150 MPa/(t(mm)) 1/2 .

14. The glass article of claim 1 , wherein the glass article comprises at least about 4 mol % P 2 O 5 , wherein (M 2 O 3 (mol %)/R x O(mol %))<1, where M 2 O 3 =Al 2 O 3 +B 2 O 3 , and where R x O is a sum of monovalent and divalent cation oxides present in the glass article.

15. The glass article of claim 1 , wherein the glass article comprises:
about 40 mol % to about 70 mol % SiO 2 ;
about 11 mol % to about 25 mol % Al 2 O 3 ;
about 2 mol % to about 15 mol % P 2 O 5 ;
about 10 mol % to about 25 mol % Na 2 O;
about 10 to about 30 mol % R x O, where R x O is a sum of alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass article.

16. A glass article, comprising:
opposing first and second surfaces defining a thickness t;
a center located at t/2;
a stress profile comprising:
a compressive region extending from the first surface to a depth of compression (DOC) that is greater than or equal to 90 μm;
a maximum compressive stress (CS) within the compressive region in a range from about 500 MPa to about 2,000 MPa;
a first region of the compressive region extending from the first surface to a depth d 1 , wherein d 1 >0.06t, and at least a portion of the first region has a first slope m 1 ;
a second region extending from d 1 to the DOC, and having a second slope m 2 , wherein |m 1 |≤|m 2 |;
a first region sub-region including an entire compressive stress spike extending from the first surface to a depth d 2 that is located at a spike compressive stress, and comprising a third slope m 3 , wherein: d 2 <d 1 , and |m 1 |<|m 3 | and 30 MPa/μm≤|m 3 |≤200 MPa/μm;
the spike compressive stress at d 2 being in a range from greater than or equal to 150 MPa to less than or equal to 180 MPa; and
a compressive region sub-region within the compressive region with a negative curvature.

17. The glass article of claim 16 having a planar configuration, wherein t is in a range from about 0.1 mm to about 1 mm.

18. The glass article of claim 16 , wherein the negative curvature has an absolute value exceeding 10 mPa/(t(mm)) 2 over a spatial extent ranging from about 2% to about 25% of t.

19. A consumer electronic product, comprising:
a housing having a front surface, a back surface, and side surfaces;
electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; and
the glass article of claim 16 disposed over the display.

20. A glass article, comprising:
opposing first and second surfaces defining a thickness t;
a center located at t/2;
a stress profile comprising:
a compressive region extending from the first surface to a depth of compression (DOC);
a maximum compressive stress (CS) within the compressive region;
a first region of the compressive region extending from the first surface to a depth d 1 , wherein d 1 >0.06t, and at least a portion of the first region has a first slope m 1 ;
a second region of the compressive region extending from d 1 to the DOC, and having a second slope m 2 , wherein |m 1 |≤|m 2 |;
a first region sub-region extending from the first surface to a depth d 2 and comprising a third slope m 3 , wherein d 2 <d 1 , and |m 1 |<|m 3 |; and
a compressive region sub-region within the compressive region having a negative curvature, the negative curvature has an absolute value exceeding 10 MPa/(t(mm)) 2 over a spatial extent ranging from about 2% to about 25% of t;
wherein a spike compressive stress at d 2 is in a range from greater than or equal to 150 MPa to less than or equal to 180 MPa.

Assignees

• Corning Inc

Inventors

• Dejneka Matthew John
• Oram Pascale
• Roussev Rostislav Vatchev
• Schneider Vitor Marino
• Smith Charlene Marie
• Tang Zhongzhi

Classifications

• G06F1/1637

  Details related to the display arrangement, including those related to the mounting of the display in the housing · CPC title

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title

• C03C21/002 Primary

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C3/083

  containing aluminium oxide or an iron compound · CPC title

• C03C4/00 Primary

  Compositions for glass with special properties · CPC title