System and method of providing a regenerating protective coating in a MEMS device

• US 20060077150A1
• Filed: 05/20/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Sampsell, Jeffrey B.
• Granted Patent: US 7,446,926 B2
• Time in Patent Office: Days
• US Class Current: 345/85
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81C 1/00944 Maintaining a critical distance between the structures to be released
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

In various embodiments of the invention, a regenerating protective coating is formed on at least one surface of an interior cavity of a MEMS device. Particular embodiments provide a regenerating protective coating on one or more mirror surfaces of an interferometric light modulation device, also known as an iMoD in some embodiments. The protective coating can be regenerated through the addition of heat or energy to the protective coating.

Claims

1. An interferometric light modulating device, comprising:

a transparent substrate;

an interferometric modulator array disposed on said transparent substrate, wherein said array comprises a transmissive layer and a reflective layer;

a protective coating disposed between at least a portion of said transmissive layer and said reflective layer; and

a heater configured to increase the temperature of said protective coating.

2. The device of claim 1, wherein said transparent substrate is sealed to a backplate to form a package, and wherein said interferometric modulator array is located within said package.

3. The device of claim 2, wherein said protective coating comprises a self-aligning monolayer.

4. The device of claim 3, wherein said self-aligning monolayer comprises one of the following:

polytetrafluoroethylene (PTFE), perfluorodecanoic carboxylic acid, octadecyltrichlorosilane (OTS), or dichlorodimethylsilane.

5. The device of claim 3, further comprising at least one hole in said package.

6. The device of claim 1, further comprising a reservoir of a protective coating material that is not on the transmissive layer or the reflective layer, wherein said reservoir of said protective coating material can serve as a source for additional protective coating in the package during a regeneration procedure.

7. The device of claim 1, wherein said protective coating is provided on at least a portion of said transmissive layer.

8. The device of claim 1, wherein said protective coating is provided on at least a portion of said reflective layer.

9. The interferometric light modulating device of claim 1, wherein said interferometric light modulating device is a display system comprising:

an electronic display comprising said interferometric light modulating array;

a processor that is in electrical communication with said interferometric light modulating array, wherein said processor is configured to process image data; and

a memory device in electrical communication with said processor.

10. The display system as recited in claim 9, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said image data to said first controller.

11. The display system as recited in claim 9, further comprising:

an image source module configured to send said image data to said processor.

12. The display system as recited in claim 11, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

13. The display system as recited in claim 9, further comprising:

an input device configured to receive input data and to communicate said input data to said processor.

14. The device of claim 2, wherein the heater is contained within the package.

15. The device of claim 14, wherein the heater comprises a metal layer on a surface within the package.

16. The device of claim 15, wherein the metal layer is part of a circuit that is dedicated to create heat.

17. The device of claim 16, wherein the metal in the metal layer comprises chrome or nickel.

18. The device of claim 14, wherein said heater comprises a looped lead involving the transmissive layer, wherein the looped lead is shorted to ground potential.

19. The device of claim 18, wherein the looped lead is configured to be switchably shorted to ground potential.

20. The device of claim 19, wherein a micro-electro-mechanical-system (MEMS) is used to make the looped lead switchable.

21. The device of claim 14, wherein said heater comprises a looped lead involving a mechanical layer that is associated with the reflective layer, wherein the looped lead is shorted to ground potential.

22. The device of claim 21 further comprising a current limiting resistor between a lead and a ground.

23. The device of claim 14, wherein the heating element is positioned on a post in the package.

24. The device of claim 23, wherein the heater is in about a same plane as that of the reflective layer in an undriven state.

25. The device of claim 23, wherein the heater on the post is positioned above the reflective layer and above the substrate.

26. The device of claim 14, wherein the heater is a bus structure that is positioned on top of a support and above a reflective layer.

27. A system for regenerating a self-aligned monolayer formed on one or more layers of a micro-electronic-mechanical-system (MEMS) device, comprising:

a MEMS device comprising a transmissive layer, a reflective layer, and a self-aligned monolayer; and

a heater positioned proximal to the MEMS device, wherein the heat emitted from said heater is sufficient to elevate the temperature of a self-aligned monolayer.

28. A method of regenerating a monolayer in a MEMS device, comprising:

providing a MEMS device comprising an interferometric modulator and a heater, wherein said interferometric modulator comprises a monolayer; and

activating said heater in order to increase the temperature of said monolayer, whereby said monolayer is regenerated.

29. A system for regenerating a protective coating on an interferometric modulator device, comprising:

an interferometric modulator device comprising a means for selectively allowing certain wavelengths of light to pass through a first layer, a means for selectively reflecting certain wavelengths of light, and a protective coating; and

a means for heating the protective coating.

30. An interferometric modulator device with a protective coating, wherein said protective coating was regenerated on either a transmissive layer or a reflective layer of the interferometric modulator device at least once.

31. A method of making a system for regenerating a self-aligned monolayer formed on one or more layers of a micro-electronic-mechanical-system (MEMS) device, comprising:

providing a MEMS device comprising a transmissive layer, a reflective layer, and a self-aligned monolayer; and

positioning a heater proximal to the MEMS device, wherein the heater is positioned so that heat emitted from said heater is sufficient to elevate the temperature of a self-aligned monolayer.