STRENGTHENED GLASS WITH DEEP DEPTH OF COMPRESSION
First Claim
1. A glass article, the glass article having a thickness t and a compressive layer having a compressive stress CS of in a range from about 500 MPa up to about 1200 MPa at a surface of the glass article, wherein:
- a. the compressive layer extends from the surface to a depth of compression DOC, wherein DOC≧
0.1·
t when t<
0.5 mm and DOC≧
50 μ
m when t≧
0.5 mm, and wherein the compressive layer has a compressive stress profile; and
b. the compressive stress profile comprises;
i. a first portion b extending from the surface to a depth db and having a slope mb, wherein 3 μ
m≦
db≦
15 μ
m and −
40 MPa/μ
m≧
ma≧
−
200 MPa/μ
m; and
ii. a second portion c extending from db to the depth of compression DOC and having a slope mc, wherein −
2 MPa/μ
m≧
mc≧
−
8 MPa/μ
m.
1 Assignment
0 Petitions
Accused Products
Abstract
Chemically strengthened glass articles having at least one deep compressive layer extending from a surface of the article to a depth of at least about 45 μm within the article are provided. In one embodiment, the compressive stress profile includes a single linear segment extending from the surface to the depth of compression DOC. Alternatively, the compressive stress profile includes two linear portions: the first portion extending from the surface to a relatively shallow depth and having a steep slope; and a second portion extending from the shallow depth to the depth of compression. The strengthened glass has a 60% survival rate when dropped from a height of 80 cm in an inverted ball drop test and an equibiaxial flexural strength of at least 10 kgf as determined by abraded ring-on-ring testing. Methods of achieving such stress profiles are also described.
-
Citations
30 Claims
-
1. A glass article, the glass article having a thickness t and a compressive layer having a compressive stress CS of in a range from about 500 MPa up to about 1200 MPa at a surface of the glass article, wherein:
-
a. the compressive layer extends from the surface to a depth of compression DOC, wherein DOC≧
0.1·
t when t<
0.5 mm and DOC≧
50 μ
m when t≧
0.5 mm, and wherein the compressive layer has a compressive stress profile; andb. the compressive stress profile comprises; i. a first portion b extending from the surface to a depth db and having a slope mb, wherein 3 μ
m≦
db≦
15 μ
m and −
40 MPa/μ
m≧
ma≧
−
200 MPa/μ
m; andii. a second portion c extending from db to the depth of compression DOC and having a slope mc, wherein −
2 MPa/μ
m≧
mc≧
−
8 MPa/μ
m. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A glass article, the glass article having a thickness t and a compressive region having a compressive stress CS in a range from about 150 MPa to about 400 MPa at a surface of the glass article, wherein:
-
a. the compressive region extends from the surface to a depth of compression DOC, wherein DOC≧
0.1·
t when t<
0.5 mm and DOC≧
50 μ
m when t≧
0.5 mm, and wherein the compressive layer has a compressive stress profile; andb. the compressive stress profile has a linear portion a extending from the surface to a depth da and a slope ma, wherein the depth da is equal to the depth of compression and −
2 MPa/μ
m≧
ma≧
−
8 MPa/μ
m. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A strengthened glass, the strengthened glass having a thickness t, an inner region under a central tension CT, and at least one compressive layer under a compressive stress CS, the compressive stress layer extending from a surface of the glass to a depth of compression DOC≧
- 0.1·
t when t<
0.5 mm and DOC≧
50 μ
m when t≧
0.5 mm, and being adjacent to the inner region, wherein the strengthened glass has at least about a 60% survival rate when dropped in an inverted ball drop test from a height of about 80 cm onto an abrasive material disposed on the surface of the glass. - View Dependent Claims (18, 19, 20, 21, 22, 23)
- 0.1·
-
24. A strengthened glass, the strengthened glass having a thickness t, an inner region under a central tension CT, and at least one compressive stress layer under a compressive stress CS, the compressive stress layer extending from a surface of the glass to a depth of compression DOC, wherein DOC≧
- 0.1·
t when t<
0.5 mm and DOC≧
50 μ
m when t≧
0.5 mm, and being adjacent to the inner region, wherein the strengthened glass has an equibiaxial flexural strength of at least 10 kgf up to about 50 kgf as determined by abraded ring-on-ring testing. - View Dependent Claims (25, 26, 27, 28, 29, 30)
- 0.1·
Specification