Methods for manufacturing cold seal fluid-filled display apparatus

• US 8,891,152 B2
• Filed: 08/12/2013
• Issued: 11/18/2014
• Est. Priority Date: 08/04/2008
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Fike, Eugene E. III, Wu, Joyce H., Steyn, Jasper Lodewyk, Gandhi, Jignesh
• Primary Examiner(s): Ben, Loha
• Application Number:
  US13/964,533
• Publication Number:
  US 20130330995A1
• Time in Patent Office: 463 Days
• Field of Search: 359/245, 359/252, 359/253, 359/228, 359290-295, 359/298, 349/122, 349/124, 349/133, 349/153, 349/156, 349/163, 349/187, 349/189, 445/24, 445/25, 445/73, 156/145, 156/146
• US Class Current: 359/253
• CPC Class Codes: B32B 2309/027 Ambient temperature
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 2457/20 Displays, e.g. liquid crystal displays, plasma displays
• CPC Class Codes: B32B 37/003 to avoid air inclusion
• CPC Class Codes: B32B 37/1018 using only vacuum
• CPC Class Codes: G02B 26/005 based on electrowetting
• 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
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: H01J 9/26 Sealing together parts of vessels

Abstract

This methods and devices described herein relate to displays and methods of manufacturing cold seal fluid-filled displays, including MEMS. The fluid substantially surrounds the moving components of the MEMS display to reduce the effects of stiction and to improve the optical and electromechanical performance of the display. The invention relates to a method for sealing a MEMS display at a lower temperature such that a vapor bubble does not form only at temperatures about 15° C. to about 20° C. below the seal temperature. In some embodiments, the MEMS display apparatus includes a first substrate, a second substrate separated from the first substrate by a gap and supporting an array of light modulators, a fluid substantially filling the gap, a plurality of spacers within the gap, and a sealing material joining the first substrate to the second substrate.

Claims

1. A method for manufacturing a display assembly including a first transparent substrate and a second transparent substrate, comprising:

cooling the first and second transparent substrates to a first temperature;

applying a fluid to at least one of the first and second transparent substrates, wherein the fluid is applied at an equilibrium vapor pressure substantially the same as a vapor pressure of the fluid;

aligning the first and second substrates; and

curing a seal material to seal the fluid between the first and second substrates along a perimeter thereof.

2. The method of claim 1, wherein the first and second transparent substrates are cooled to the first temperature prior to applying the fluid to the at least one of the first and second transparent substrates.

3. The method of claim 2, wherein the first and second substrates are held at substantially the first temperature while applying the fluid to the at least one of the first and second transparent substrates, while aligning the first and second substrates, and while curing the seal material.

4. The method of claim 1, wherein the first temperature is below room temperature.

5. The method of claim 4, wherein the room temperature is between about 18°

C. and about 30°

C.

6. The method of claim 1, further comprising providing a plurality of spacers connected to the first and second substrates to establish a gap between the two substrates.

7. The method of claim 6, wherein the plurality of spacers maintain at least a first gap between the two substrates.

8. The method of claim 1, further comprising fabricating an aperture layer on the second transparent substrate.

9. The method of claim 8, wherein applying the fluid includes applying the fluid directly to an open face of the second transparent substrate.

10. The method of claim 9, wherein applying the fluid includes spreading the fluid over the open face of the second transparent substrate until confined by the perimeter of the seal material.

11. The method of claim 1, wherein the first temperature is below about 0°

C.

12. The method of claim 1, wherein the fluid includes a hydrofluoroether liquid or a liquid blend of at least one perfluorocarbon and at least one hydrofluoroether.

13. The method of claim 1, wherein at least one array of MEMS light modulators is formed on the at least one of the first and second transparent substrates.

14. The method of claim 1, wherein a control matrix is fabricated on the at least one of the first and second transparent substrates.

15. The method of claim 1, further comprising applying a conductive adhesive to the at least one of the first and second transparent substrates.

16. The method of claim 1, further comprising venting the display assembly to atmospheric pressure.

17. The method of claim 1, wherein the seal material is contiguous.

18. The method of claim 1, further comprising curing the seal material for a first period of time.

19. The method of claim 18, wherein the first period of time is based at least in part on the time needed for the seal material to wick a particular distance into the display assembly.

20. The method of claim 1, further comprising warming the display assembly to substantially room temperature.