Micromechanical device including time-release passivant

• US 5,939,785 A
• Filed: 04/03/1997
• Issued: 08/17/1999
• Est. Priority Date: 04/12/1996
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Reed, Mark, Yeh, Arlene Y., Klonis, Homer B.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Kelley, Nathan K.
• Application Number:
  US08/833,166
• Time in Patent Office: 866 Days
• Field of Search: 257/254, 257/417, 257/420, 257/682, 257/431, 257/729, 359/838, 359/896
• US Class Current: 257/729
• CPC Class Codes: B81B 3/0016 Arrangements for avoiding sticking of the flexible or moving parts not provided for in groups B81B3/0005 - B81B3/0013
• 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 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An electronic device (10) such as that of the micromechanical type having a time-released source of a passivant (20). This source (20) is preferably comprised of an impregnated molecular sieve/binder combination, preferably being a polymer. The passivant may be PFDA. The time-released passivant source continuously over the life of the device reduces any tendency of engaged or contacting elements to stick, adhere, or otherwise resist separation. The present invention finds particular use in spatial light modulators of the DMD type. The molecular sieve/binder can also include getter/desiccant source, such as a non-evaporable getter to remove moisture from the hermetically sealed electronic device.

Claims

1. A device comprising:

a sealed enclosure surrounding a micromechanical device; and

material disposed in said sealed enclosure, said material including a long-chain aliphatic halogenated compound passivant, whereby said material releases said passivant continuously to coat contacting surfaces of said microelectronic device.

2. The device as specified in claim 1 wherein said material further comprises a desiccant (getter).

3. The device as specified in claim 1 wherein said material is impregnated with said passivant.

4. The device as specified in claim 1 wherein said material is a polymer.

5. The device as specified in claim 1 wherein said passivant comprises PFDA.

6. The device as specified in claim 1 wherein said desiccant comprises an alumino-silicate.

7. The device as specified in claim 1 wherein said material comprises an adhesive or paste.

8. The device as specified in claim 1 wherein said material comprises a molecular sieve/binder.

9. The device as specified in claim 1 wherein said electronic device is a micromechanical device.

10. The device as specified in claim 9 wherein said micromechanical device is a spatial light modulator.

11. The device as specified in claim 1 wherein said enclosure is hermetically sealed.

12. The device as specified in claim 1 wherein said material is disposed on an interior surface of said enclosure.

13. The device as specified in claim 12 wherein said material is affixed on a top interior surface of said enclosure above said electronic device.

14. The device as specified in claim 1 wherein said material is polyvinyl butyral.

15. A device comprising:

a sealed enclosure surrounding a micromechanical device; and

material disposed in said sealed enclosure, said material including a passivant comprised of a perfluoroalkanoic acid, whereby said material releases said passivant continuously to coat contacting surfaces of said microelectronic device.