Durable glass housings/enclosures for electronic devices

• US 8,187,987 B2
• Filed: 08/21/2009
• Issued: 05/29/2012
• Est. Priority Date: 08/21/2008
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Amin, Jaymin, Dejneka, Matthew John, Pinckney, Linda Ruth, Rossington, Katherine Rose, Sabia, Robert
• Primary Examiner(s): Lorengo, Jerry
• Assistant Examiner(s): WIESE, NOAH S
• Application Number:
  US12/545,475
• Publication Number:
  US 20100047521A1
• Time in Patent Office: 1,012 Days
• Field of Search: 501/65, 501/66, 501/67, 501/68, 501/69, 501/70, 65/301.3, 65/301.4, 65/69, 65/95, 651/04, 651/14
• US Class Current: 501/69
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 3/083 containing aluminium oxide or an iron compound
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: Y10T 428/131 Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

The invention relates to glass articles suitable for use as electronic device housing/enclosure or protective cover which comprise a glass material. Particularly, a housing/enclosure/cover comprising an ion-exchanged glass exhibiting the following attributes (1) radio, and microwave frequency transparency, as defined by a loss tangent of less than 0.03 and at a frequency range of between 15 MHz to 3.0 GHz; (2) infrared transparency; (3) a fracture toughness of greater than 0.6 MPa·m^1/2; (4) a 4-point bend strength of greater than 350 MPa; (5) a Vickers hardness of at least 450 kgf/mm² and a Vickers median/radial crack initiation threshold of at least 5 kgf, (6) a Young'"'"'s Modulus ranging between about 50 to 100 GPa; (7) a thermal conductivity of less than 2.0 W/m° C., and (9) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

Claims

1. An article suitable for housing, enclosing or covering the components of a portable electronic device, the article comprising an ion exchanged alkali-aluminosilicate glass consisting essentially of 64 mol %≦

SiO₂≦

68 mol %;

12 mol %≦

Na₂O≦

16 mol %;

8 mol %≦

Al₂O₃≦

12 mol %;

0 mol % ≦

B₂O₃≦

3 mol %;

2 mol %≦

K₂O≦

5 mol %;

4 mol %≦

MgO≦

6 mol %; and

0 mol %≦

CaO≦

5 mol %, wherein;

66 mol %≦

SiO₂+B₂O₃ +CaO≦

69 mol %;

Na₂O+K₂O +B₂O₃+MgO+CaO+SrO>

10 mol %;

5 mol %≦

MgO+CaO+SrO≦

8 mol %;

2 mol %≦

Na₂O−

Al₂O₃≦

6 mol %; and

4 mol %≦

(Na₂O+K₂O)−

Al₂O₃≦

10 mol %, and exhibiting radio and microwave frequency transparency, as defined by a loss tangent of less than 0.03 and at a frequency range of between 15 MHz to 3.0 GHz, infrared transparency, a fracture toughness of greater than 0.60 Mpa·

m^1/2, a 4-point bend strength of greater than 350 MPa, a Vickers hardness of at least 450 kgf/mm², a Vickers median/radial crack initiation threshold of at least 5 kgf, a Young'"'"'s Modulus ranging between 50 to 100 GPa, a thermal conductivity of less than 2.0 W/m°

C. and at least one of the following attributes;

(i) a compressive surface layer having a depth of layer (DOL) greater than or equal to 20 μ

m and a compressive stress greater than 400 MPa, or,

(ii) a central tension of more than 20 MPa.

2. The article claimed in claim 1 wherein the glass exhibits a refractive index of greater then 1.47 at 633 nm.

3. The article claimed in claim 1 wherein the glass exhibits radio and microwave frequency transparency, as defined by a loss tangent of less than 0.015 at a frequency range of between 500 MHz to 3.0 GHz.

4. The article claimed in claim 1 wherein the glass exhibits a fracture toughness of greater than 0.75 Mpa·

m^1/2.

5. The article claimed in claim 1 wherein the glass exhibits a Young'"'"'s Modulus ranging between 50 and 75 GPa.

6. The article claimed in claim 1 wherein the glass exhibits an 4-point bend strength of greater than 475 MPa.

7. The article claimed in claim 1 wherein the glass exhibits a Vickers hardness of at least 500 kgf/mm² and Vickers median/radial crack initiation threshold of greater than 10 kgf.

8. The article claimed in claim 1 wherein the glass exhibits a thermal conductivity of less than 1.5 W/m°

C.

9. The article claimed in claim 1 wherein the glass article is transparent and exhibits at least one surface having a Ra roughness of less than less than 50 nm.

10. The article claimed in claim 1 wherein the glass article appears opaque and exhibits at least one surface having a Ra roughness of between 50 nm and 15 μ

m.

11. The article as claimed in claim 1 wherein the glass exhibits a near-infra-red transparency of greater than 80% at a wavelength ranging from 750 to 2000 nm.

12. The article as claimed in claim 1 wherein the article exhibits an overall thickness of 1.2 mm and compressive layer exhibiting a DOL of ranging between 40 to 80 μ

m and the compressive layer exhibits a compressive stress of 525 MPa.

13. The article as claimed in claim 1 wherein the glass exhibits a liquidus viscosity of greater than 130,000 poise at temperatures below 1275°

C.

14. The article as claimed in claim 1 wherein the glass is fusion formable and the article is formed by standard processing techniques selected from the group consisting of pressing, sagging, vacuum sagging, sheet coin and combinations thereof.