OLEOPHOBIC COATING ON SAPPHIRE

• US 20140087197A1
• Filed: 09/23/2013
• Published: 03/27/2014
• Est. Priority Date: 09/21/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Weber, Douglas, Matsuyuki, Naoto
• Granted Patent: US 8,974,924 B2
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films G02B1/16 takes precedence
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A component comprises a substrate having an alumina base layer, a transition layer, and a surface coating. The transition layer comprises alumina and silica, and the surface coating preferentially bonds to the silica as compared to the alumina.

Claims

1. A component comprising:

a substrate having an alumina base layer;

a transition layer on the substrate, the transition layer comprising alumina and silica; and

a surface coating on the substrate, wherein the surface coating preferentially bonds to the silica as compared to the alumina.

2. The component of claim 1, wherein the alumina base layer comprises a substantially single-crystal sapphire.

3. The component of claim 1, wherein the transition layer transitions substantially continuously from about 100% alumina at the base layer to include a substantial silica component at the surface coating.

4. The component of claim 1, wherein the transition layer transitions substantially continuously from about 100% alumina at the substrate to about 100% silica or silica glass at the surface coating.

5. The component of claim 1, further comprising a surface layer formed on the transition layer, wherein the surface layer comprises a substantially constant silica component and the surface coating preferentially bonds to the silica in the surface layer.

6. The component of claim 5, wherein the surface layer comprises substantially 100% silica or silica glass.

7. The component of claim 1, wherein the surface coating comprises an oleophobic coating.

8. A portable electronic device comprising the component of claim 7.

9. The portable electronic device of claim 8, wherein the component comprises a window, and wherein the olephobic coating is provided on an exterior surface of the window.

10. The portable electronic device of claim 9, further comprising a touch screen in the window.

11. A window for a portable electronic device, the window comprising:

a substrate having a sapphire glass base layer;

a transition layer on the sapphire glass base layer, the transition layer comprising alumina and silica; and

an oleophobic surface coating on the substrate, wherein the oleophobic surface coating preferentially bonds to the silica as compared to the alumina.

12. The window of claim 11, wherein the transition layer transitions from at least 90% alumina at the base layer to at least 50% silica or silica glass at the oleophobic coating.

13. The window of claim 12, wherein the transition layer transitions to at least 90% silica or silica glass at the oleophobic coating.

14. The window of claim 11, wherein the oleophobic coating comprises an alkylsilane and a perfluorinated end group.

15. The window of claim 11, further comprising a touch screen provided in the window, wherein the oleophobic surface coating is provided on an exterior surface of the touch screen.

16. A method comprising:

providing sapphire substrate for a touch screen window, the sapphire substrate having a substantially single crystal base layer;

forming a transition layer on the sapphire substrate, the transition layer comprising alumina and silica; and

forming a surface coating on the substrate, wherein the surface coating preferentially bonds to the silica as compared to the alumina.

17. The method of claim 16, wherein forming the transition layer comprises vapor deposition of alumina and silica onto the sapphire substrate.

18. The method of claim 16, wherein forming the transition layer comprises transitioning from substantially 100% alumina at the sapphire substrate to more than 50% silica or silica glass at the surface coating.

19. The method of claim 18, wherein forming the transition layer comprises transitioning from substantially 100% alumina at the sapphire substrate to substantially 100% silica or silica glass at the surface coating.

20. The method of claim 19, wherein forming a surface coating comprises forming an oleophobic coating on the substrate, wherein the oleophobic coating comprises an end group that preferentially bonds to the silica, as compared to the alumina.