Method and device for packaging a substrate

• US 7,424,198 B2
• Filed: 01/28/2005
• Issued: 09/09/2008
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Palmateer, Lauren, Chui, Clarence, Sampsell, Jeffrey B., Cummings, William J., Kothari, Manish, Gally, Brian, Miles, Mark
• Primary Examiner(s): KIM, ELLEN E
• Application Number:
  US11/045,738
• Publication Number:
  US 20060067641A1
• Time in Patent Office: 1,320 Days
• Field of Search: 385/147, 359/247, 359/291
• US Class Current: 385/147
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81C 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• 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
• CPC Class Codes: G02B 26/007 the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light
• CPC Class Codes: G02B 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B

Abstract

A package structure and method of packaging for an interferometric modulator. A thin film material is deposited over an interferometric modulator and transparent substrate to encapsulate the interferometric modulator. A gap or cavity between the interferometric modulator and the thin film provides a space in which mechanical parts of the interferometric modulator may move. The gap is created by removal of a sacrificial layer that is deposited over the interferometric modulator.

Claims

1. A display device comprising an array of movable mirrors configured to interferometrically modulate light, the display device comprising:

a transparent substrate;

an interferometric modulator comprising the array of movable mirrors, wherein said interfereometric modulator is configured to modulate light transmitted through said transparent substrate, and

a thin film backplane sealing said array of movable mirrors within a package between said transparent substrate and said thin film backplane, wherein a gap exists between said array of movable mirrors and said thin film backplane.

2. The display device of claim 1, wherein said gap is formed from removal of a sacrificial layer located between said array of movable mirrors and said thin film backplane.

3. The display device of claim 1, wherein the thin film backplane comprises a hermetic material.

4. The display device of claim 1, wherein the thin film is nickel.

5. The display device of claim 1, wherein the thin film is aluminum.

33. The display device of claim 1, wherein the interferometric modulator is organized into an array.

6. A method of manufacturing a display comprising an array of movable mirrors configured to interferometrically modulate light, the method comprising:

providing a transparent substrate;

forming an interferometric modulator on the transparent substrate, and wherein said interferometric modulator comprises the array of movable mirrors; and

depositing a thin film backplane over the array of movable mirrors and the transparent substrate to seal said array of movable mirrors between said transparent substrate and said thin film backplane, wherein a gap exist between said array of movable mirrors and said thin film backplane.

7. The method of claim 6, further comprising:

depositing a sacrificial layer on said interferometric modulator prior to depositing said thin film backplane; and

removing said sacrificial layer after depositing said thin film backplane in order to provide a gap between said interferometric modulator and said thin film backplane.

8. The method of claim 7, further comprising patterning said thin film backplane to create at least one opening in said thin film backplane.

9. The method of claim 7, further comprising patterning said thin film backplane to expose a portion of said sacrificial layer.

10. The method of claim 6, wherein the thin film backplane is formed of aluminum.

11. The method of claim 6, wherein the thin film backplane is formed of nickel.

12. The method of claim 6, wherein the thin film backplane is formed of spin-on glass.

13. The method of claim 6, wherein the thin film backplane is formed of a hermetic material.

14. The method of claim 7, wherein the sacrificial layer is formed of spin-on glass.

31. The method of claim 6 further comprising depositing a sacrificial layer over the array of movable mirrors prior to depositing said thin film backplane.

32. The method of claim 31, wherein depositing a sacrificial layer over the array of movable mirrors comprises depositing the thin film backplane over at least a portion of the sacrificial layer.

15. A microelectromechanical systems display device comprising an array of movable mirrors configured to interferometrically modulate light, the microelectromechanical systems display device comprising:

a transparent substrate;

an interferometric modulator formed on the transparent substrate, the interferometric modulators comprising the array of movable mirrors; and

a thin film backplane sealed to the transparent substrate to encapsulate the array of movable mirrors between the transparent substrate and the thin film backplane, wherein a cavity exists between the array of movable mirrors and the thin film backplane.

16. The microelectromechanical systems display device of claim 15, wherein the cavity is created by removing a sacrificial layer between the array of movable mirrors and the thin film backplane.

17. The microelectromechanical systems display device of claim 15, wherein the cavity allows one or more movable mirrors in the array of movable mirrors to move.

18. The microelectromechanical systems display device of claim 15, wherein the thin film backplane comprises a hermetic material.

19. The microelectromechanical systems display device of claim 15, further comprising an overcoat layer deposited over the thin film backplane.

20. The microelectromechanical systems display device of claim 19, wherein the overcoat layer comprises a vapor barrier material.

21. The microelectromechanical systems display device of claim 19, wherein the overcoat layer comprises a polymer.

22. The microelectromechanical systems display device of claim 15, wherein the thin film backplane comprises a metal.

23. The microelectromechanical systems display device of claim 15, wherein the thin film backplane comprises a polymer.

24. A display device comprising an array of moveable mirrors configured to interferometrically modulate light, the display device comprising:

a transparent substrate;

an interferometric modulator comprising the array of movable mirrors, wherein said interferometric modulator is configured to modulate light transmitted through the transparent substrate, and wherein said interferometric modulator is formed on the transparent substrate,

a thin film backplane deposited over the array of movable mirrors, wherein the thin film backplane seals the array of movable mirrors within a package between the transparent substrate and the thin film backplane; and

a cavity between the array of moveable mirrors and the thin film backplane, wherein the cavity is formed by removing a sacrificial material.

25. The display device of claim 24, wherein the thin film backplane is hermetic.

26. The display device of claim 24, wherein the thin film backplane is a metal.

27. The display device of claim 24, wherein the thin film backplane is a polymer.

28. A display device comprising an array of movable mirrors configured to interferometrically modulate light, the 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, wherein said interferometric modulator comprises the array of movable mirrors; and

a sealing means for sealing the array of movable mirrors within a package between the transmitting means and the sealing means, wherein the sealing means comprises a thin film, and wherein a cavity exists between the array of movable mirrors and the sealing means.

29. The display device of claim 28, wherein the sealing means comprises a hermetic material.

30. The display device of claim 28, wherein the thin film is permeable to xenon diflouride and the sealing means further comprises a hermetic material formed over the thin film.