MEMS DEVICES AND PROCESSES FOR PACKAGING SUCH DEVICES

• US 20070242341A1
• Filed: 04/12/2007
• Published: 10/18/2007
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm, Inc.
• Inventors: Ganti, Surya, Natarajan, Bangalore
• Granted Patent: US 7,746,537 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• 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 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: B81C 2203/032 Gluing
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B

Abstract

A package structure and method of packaging for a MEMS device is described. A transparent substrate having an interferometric modulator array formed thereon is shown. A single or dual-layered backplate is joined to the transparent substrate with a seal. The interferometric modulator array may be exposed to the surrounding environment through an opening in either the backplate or the seal.

Claims

1. A method of manufacturing a microelectromechanical systems (MEMS) based display device, the method comprising:

providing a transparent substrate comprising at least one MEMS device formed thereon;

providing a first backplate comprising at least one orifice;

providing at least one second backplate comprising at least one desiccant area; and

forming a MEMS package wherein said transparent substrate is joined to said first backplate, and said first backplate is joined to said at least one second backplate.

2. The method of claim 1, further comprising sealing said at least one orifice.

3. The method of claim 1, further comprising introducing a release material through the at least one orifice before joining the first backplate to the at least one second backplate.

4. The method of claim 3, wherein the release material is xenon difluoride.

5. The method of claim 1, wherein said transparent substrate comprises a plurality of MEMS devices, and said method further comprises scribing and breaking said plurality of MEMS devices into separate panels.

6. The method of claim 5, wherein the MEMS devices comprise interferometric modulator arrays.

7. The method of claim 1, wherein the method takes place in ambient conditions.

8. The method of claim 1, wherein said at least one MEMS device comprises an interferometric modulator device.

9. The method of claim 1, wherein said at least one orifice and said at least one desiccant area are aligned so that said at least one MEMS device is exposed to said desiccant.

10. The method of claim 9, wherein said MEMS display device comprises a plurality of interferometric modulator arrays provided on a single transparent substrate and said first backplate comprises a plurality of orifices aligned above said arrays.

11. The method of claim 10, wherein the at least one second backplate comprises a plurality of second backplates sealed to said first substrate.

12. The method of claim 11, wherein the second backplates comprise metal backplates.

13. The method of claim 11, wherein said plurality of second backplates are sealed to said first backplate by contacting a flexible carrier comprising said second backplates to said first backplate

14. The method of claim 13 wherein said second backplates are removably attached to said flexible carrier.

15. The method of claim 13, wherein contacting said flexible carrier comprises unrolling said flexible carrier.

16. A display device made by the method of claim 1.

17. A microelectromechanical systems (MEMS) based device, comprising:

a transparent substrate having a MEMS device formed thereon;

a first backplate sealed to said transparent substrate, the first backplate comprising at least one orifice; and

a second backplate joined to said first backplate, and comprising at least one desiccant area, wherein said at least one desiccant area is exposed to said MEMS device through said at least one orifice.

18. The device of claim 17, wherein said transparent substrate comprises glass.

19. The device of claim 17, wherein said first backplate comprises glass.

20. The device of claim 17, wherein the second backplate comprises glass or metal.

21. The device of claim 17, wherein the MEMS device comprises an interferometric modulator.

22. The device of claim 17, further comprising:

a processor that is in electrical communication with said microelectromechanical system device, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

23. The device of claim 22, further comprising a driver circuit configured to send at least one signal to said microelectromechanical system device.

24. The device of claim 23, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

25. The device of claim 22, further comprising an image source module configured to send said image data to said processor.

26. The device of claim 25, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

27. The device of claim 22, further comprising an input device configured to receive input data and to communicate said input data to said processor.

28. A method of manufacturing a microelectromechanical systems (MEMS) based display device, comprising:

providing a package formed by a transparent substrate having a MEMS device formed thereon and a backplate sealed to said transparent substrate with a sealant, wherein an orifice is provided in said backplate; and

sealing said orifice with a plug, wherein said plug comprises a desiccant.

29. The method of claim 28, wherein said plug comprises a glass plug.

30. The method of claim 28, wherein said plug comprises a tapered plug.

31. The method of claim 28, wherein said desiccant comprises at least one of calcium oxide, strontium oxide (SrO), a silica gel, montmorillonite clay, a magnesium aluminum, a molecular sieve, a zeolite, and a calcium sulfate.

32. A microelectromechanical systems (MEMS) based device, comprising:

means for supporting a MEMS device, having a MEMS device formed thereon;

first means for sealing comprising at least one orifice; and

second means for sealing joined to said first sealing means, and comprising at least one desiccant area, wherein said at least one desiccant area is exposed to said MEMS device through said at least one orifice.

33. The device of claim 32, wherein the supporting means comprises a transparent substrate.

34. The device of claim 32, wherein the first sealing means comprises a first backplate.

35. The device of claim 32, wherein the second sealing means comprises a second backplate.

36. The device of claim 32, wherein said supporting means comprises glass.

37. The device of claim 32, wherein said first sealing means comprises glass.

38. The device of claim 32, wherein the second sealing means comprises glass.

39. The device of claim 32, wherein the MEMS device comprises an interferometric modulator.

40. The device of claim 32, further comprising:

a processor that is in electrical communication with said microelectromechanical system device, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

41. The device of claim 40, further comprising a driver circuit configured to send at least one signal to said microelectromechanical system device.

42. The device of claim 41, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

43. The device of claim 40, further comprising an image source module configured to send said image data to said processor.

44. The device of claim 43, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

45. The device of claim 40, further comprising an input device configured to receive input data and to communicate said input data to said processor.