Surface-tensioned sapphire plate

• US 9,617,639 B2
• Filed: 08/06/2014
• Issued: 04/11/2017
• Est. Priority Date: 03/18/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Kress, Markus, Beckmann, Rudolf
• Primary Examiner(s): SAMPLE, DAVID R
• Application Number:
  US14/453,065
• Publication Number:
  US 20140349092A1
• Time in Patent Office: 979 Days
• Field of Search: None
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C23C 14/081 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: C23C 14/582 using electron bombardment
• CPC Class Codes: C23C 16/403 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 16/513 using plasma jets
• CPC Class Codes: C30B 29/20 Aluminium oxides
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/266 of base or substrate

Abstract

A surface-tensioned sapphire plate and a corresponding manufacturing process. The plate may include a planar sapphire substrate and at least one layer disposed on the surface of the substrate for tensing the substrate. The layer may include at least 50 wt.-% of aluminum oxide (Al2O3). The manufacturing process for producing of a sapphire plate may include providing a planar sapphire substrate, and coating at least one surface of the substrate with a layer tensing the substrate. The layer may include at least 50 wt.-% of aluminum oxide (Al2O3).

Claims

1. A surface-tensioned sapphire plate comprising:

a planar sapphire substrate;

at least one layer disposed on the surface of the substrate and exhibiting a residual tensile stress;

wherein the layer has at least 50 wt.-% of aluminum oxide (Al2O3).

2. The sapphire plate of claim 1, wherein the layer comprises amorphous aluminum oxide (Al2O3).

3. The sapphire plate of claim 1, wherein the layer has a layer thickness of one of at least:

100 nm, 200 nm, 300 nm, 500 nm, 750 nm, 1000 nm, 1100 nm or 1500 nm.

4. The sapphire plate of claim 1, wherein an interface surface of the sapphire substrate substantially coincides with the A axis crystalline orientation of sapphire or the C axis crystalline orientation of sapphire, the interface surface disposed adjacent the at least one layer.

5. The sapphire plate of claim 1, wherein the layer substantially comprises aluminum oxide (Al2O3) or substantially consists of aluminum oxide (Al2O3).

6. The sapphire plate of claim 1, wherein the layer comprises at least one of:

0 to 5 wt.-% of carbon,

0 to 10 wt.-% of hydrogen, and

0 to 5 wt.-% of nitrogen.

7. The sapphire plate of claim 6, wherein the layer includes at least 80 wt.-% of aluminum oxide (Al2O3).

8. The sapphire plate of claim 1, wherein the layer is substantially transparent to electromagnetic radiation in a visible wavelength range.

9. The sapphire plate of claim 1, wherein the planar sapphire substrate includes a thickness of 0.2 mm to 2 mm.

10. The sapphire plate of claim 1, wherein the sapphire substrate includes a first thermal expansion coefficient, and

the layer includes a second thermal expansion coefficient, distinct from the first thermal expansion coefficient of the sapphire substrate.

11. A surface-tensioned sapphire plate, comprising:

a sapphire structure having a first thermal expansion coefficient;

a layer adhered to the sapphire structure and having a second thermal expansion coefficient; and

wherein;

the layer has at least 50 wt.-% of aluminum oxide (Al2O3); and

the second thermal expansion coefficient is greater than the first thermal expansion coefficient.

12. The sapphire plate of claim 11, wherein the layer comprises amorphous aluminum oxide (Al2O3).

13. The sapphire plate of claim 11, wherein the layer comprises at least one of:

0 to 5 wt.-% of carbon,

0 to 10 wt.-% of hydrogen, and

0 to 5 wt.-% of nitrogen.

14. A surface-tensioned sapphire plate, comprising:

a sapphire sheet having a first surface with a number of surface defects;

a layer affixed to the first surface, the layer comprising at least 50 wt.-% of aluminum oxide (Al2O3); and

wherein the layer is configured to induce a compressive stress within the sapphire sheet to press together at least one of the surface defects.

15. The sapphire plate of claim 14, wherein the layer comprises amorphous aluminum oxide (Al2O3).

16. The sapphire plate of claim 14, wherein the layer comprises at least one of:

0 to 5 wt.-% of carbon,

0 to 10 wt.-% of hydrogen, and

0 to 5 wt.-% of nitrogen.