System and method for display device with integrated desiccant

• US 20060077146A1
• Filed: 04/15/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Palmateer, Lauren
• Granted Patent: US 7,551,246 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: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• 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

A package structure and method of packaging an interferometric modulator with an integrated desiccant. An interferometric modulator is formed on a transparent substrate. A backplane is joined to the transparent substrate to form a package structure and to encapsulate the interferometric modulator. A desiccant integrated into the backplane or the transparent substrate is provided to absorb moisture within the package.

Claims

1. A display device, comprising:

a transparent substrate;

an interferometric modulator configured to modulate light transmitted through the transparent substrate; and

a backplane cover disposed on the modulator and sealing the modulator within a package between said transparent substrate and the backplane cover, wherein the backplane cover has an integrated desiccant configured to absorb moisture within the package.

2. The display device of claim 1, wherein the backplane cover is formed of a material comprising a desiccant.

3. The display device of claim 2, wherein the material comprises a polymer and one of a molecular sieve or silica gel.

4. The display device of claim 2, wherein the material comprises a desiccant, a channeling agent, and a polymer.

5. The display device of claim 2, wherein the material can be molded or extruded.

6. The display device of claim 2, wherein the desiccant is applied to a surface of the backplane cover as a spray coat.

7. The display device of claim 2, wherein the desiccant is applied to recessed areas formed in a surface of the backplane.

8. The display device of claim 1, wherein the desiccant is a zeolite.

9. The display device of claim 1, wherein the desiccant is calcium oxide.

10. The display device of claim 1, wherein the transparent substrate has an integrated desiccant configured to absorb moisture within the package.

11. A method of manufacturing a display device, comprising:

providing a transparent substrate;

forming an interferometric modulator on the transparent substrate;

joining a backplane to the transparent substrate to form a package, wherein the package encapsulates the interferometric modulator; and

providing within the package a desiccant contained within a membrane.

12. The method of claim 11, wherein the membrane is adhered to the backplane.

13. The method of claim 11, wherein the membrane is adhered to the transparent substrate.

14. The method of claim 11, wherein the membrane is formed of polyethylene.

15. The method of claim 11, wherein the desiccant is selected from a group consisting of zeolites, calcium sulfate, calcium oxide, silica gel, molecular sieves, surface adsorbents, bulk adsorbents, chemical reactants, and indicating silica gel.

16. A display device, comprising:

a package comprising a transparent substrate, a backplane, and a seal applied between the backplane and the transparent substrate;

an electronic display configured to modulate light transmitted through the transparent substrate, wherein the electronic display is formed on the transparent substrate and positioned between the transparent substrate and the backplane; and

a desiccant contained within a pouch adhered inside the package, wherein the desiccant is configured to absorb moisture within the package.

17. The display device of claim 16, wherein the desiccant is adhered to an interior surface of the backplane.

18. The display device of claim 16, wherein the desiccant is adhered to the transparent substrate.

19. The display device of claim 16, wherein the pouch is formed of polyethylene.

20. A display device, comprising:

a transmitting means for transmitting light therethrough;

a modulating means configured to modulating light transmitted through the transmitting means, wherein the modulating means comprises an interferometric modulator;

an encapsulating means for sealing the modulating means within a package between the transmitting means and the encapsulating means; and

a moisture absorbing means integrated into either the transmitting means or the encapsulating means, the moisture absorbing means configured to absorb moisture within the package.

21. The display device of claim 20, wherein the moisture absorbing means is selected from a group consisting of zeolites, calcium sulfate, calcium oxide, silica gel, molecular sieves, surface adsorbents, bulk adsorbents, chemical reactants, and indicating silica gel.

22. The display device of claim 20, wherein the encapsulating means is formed of a material comprising the moisture absorbing means.

23. The display device of claim 20, wherein at least a portion of the encapsulating means is formed of a material comprising the moisture absorbing means.

24. A display device, comprising:

a transparent substrate;

an electronic display configured to modulate light transmitted through the transparent substrate, wherein the electronic display is formed on the transparent substrate;

a backplane joined to the transparent substrate to form a package, wherein the electronic display is positioned between the backplane and the transparent substrate; and

a desiccant within at least one pouch in the package, the desiccant being configured to absorb moisture within the package.

25. The display device of claim 24, wherein the at least one pouch is adhered to the backplane.

26. The display device of claim 24, wherein the at least one pouch is adhered to the transparent substrate.

27. The display device of claim 24, wherein the desiccant is contained in two pouches.

28. The display device of claim 27, wherein each of the two pouches contains a different type of desiccant.

29. A method of manufacturing a backplane, comprising:

providing a backplane having a recessed area on a surface, wherein the recessed area is created by applying a mask to the surface of the backplane and etching an area of the backplane exposed by the mask; and

applying desiccant to the recessed area on the interior surface while the mask is on the surface.

30. The method of claim 29, wherein etching is sandblasting.

31. The method of claim 29, wherein etching is wet etching.

32. The method of Claim, 29, further comprising:

providing a transparent substrate having an interferometric modulator formed thereon; and

joining the backplane to the transparent substrate to form a package after applying the desiccant, wherein the surface is an interior surface of the backplane.