Diluent assisted lubrication of micromechanical devices

• US 6,475,570 B2
• Filed: 12/31/2001
• Issued: 11/05/2002
• Est. Priority Date: 12/29/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Jacobs, Simon Joshua
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US10/036,611
• Publication Number:
  US 20020086101A1
• Time in Patent Office: 309 Days
• Field of Search: 427/421, 427/58, 427/96, 427/255.25, 427/255.3
• US Class Current: 427/58
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 5/083 involving the use of fluoropolymers
• CPC Class Codes: B81B 3/0005 Anti-stiction coatings
• CPC Class Codes: B81C 1/0096 For avoiding stiction when the device is in use, i.e. after manufacture has been completed
• CPC Class Codes: B81C 2201/0181 Physical Vapour Deposition [PVD], i.e. evaporation, sputtering, ion plating or plasma assisted deposition, ion cluster beam technology
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts

Abstract

A method and apparatus for delivering a fine mist of a lubricant to a micromechanical device. A mixture 402 of a lubricant and a diluent carrier fluid is held in a supply reservoir 404. The mixture is forced through a nebulizer tip 406 to produce a fine aerosol. A particle selector 408 removes large droplets from the aerosol as the aerosol passes. The aerosol travels a distance through a delivery conduit 410 while the diluent carrier fluid evaporates from the nebulized droplets. The evaporation removes the vast majority of the diluent carrier fluid from the droplets, greatly reducing the size of the lubricant droplets. The evaporated aerosol enters a deposition chamber 412 and is deposited on a micromechanical device 414. The micromechanical devices may be lubricated in wafer form, in which case the lubricant aerosol will lubricate an entire wafer of micromechanical devices at one time. One embodiment produces an aerosol having a mean droplet size of less than 10 microns. Evaporation of the diluent carrier fluid reduces this droplet size to 10-500 nm by the time the lubricant is deposited on the micromechanical devices. The preceding abstract is submitted with the understanding that it only will be used to assist in determining, from a cursory inspection, the nature and gist of the technical disclosure as described in 37 C.F.R. §1.72(b). In no case should this abstract be used for interpreting the scope of any patent claims.

Claims

1. A method of coating the surfaces of a micromechanical device, the method comprising:

mixing a coating material with a carrier fluid;

nebulizing said mixture to form an aerosol of droplets of said mixture;

evaporating a majority of said carrier fluid from said aerosol;

exposing said micromechanical device to said evaporated aerosol; and

depositing said evaporated droplets of coating material on said micromechanical device.

2. The method of claim 1, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 25% by weight of said coating material.

3. The method of claim 1, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 1 part per million by weight of said coating material.

4. The method of claim 1, said mixing comprising:

mixing a coating material selected from the group consisting of perfluoropolyethers, fluorocarbon oligomers, perfluorinated carboxylic acids, partially fluorinated carboxylic acids, and perfluorodecanoic acid with a carrier fluid.

5. The method of claim 1, said mixing comprising:

mixing a coating material with a carrier fluid selected from the group consisting of perfluorocarbon and hydrofluoroether.

6. The method of claim 1, said mixing comprising:

mixing a coating material with a volatile organic liquid.

7. The method of claim 1, comprising:

removing large droplets from said aerosol.

8. The method of claim 1, comprising:

allowing large droplets of said aerosol to settle out of said aerosol away from said micromechanical device.

9. The method of claim 1, said nebulizing comprising:

nebulizing said mixture to form an aerosol of droplets of said mixture having a mean particle diameter less than 10 microns.

10. The method of claim 1, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter less than 500 nm.

11. The method of claim 1, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter between 10 and 500 nm.

12. The method of claim 1, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a particle diameter less than 500 nm.

13. The method of claim 1, said evaporating comprising:

evaporating all of said carrier fluid from said aerosol.

14. A method of coating the surfaces of a micromechanical device, the method comprising:

mixing a coating material selected from the group consisting of perfluoropolyethers, fluorocarbon oligomers, perfluorinated carboxylic acids, partially fluorinated carboxylic acids, and perfluorodecanoic acid with a carrier fluid selected from the group consisting of perfluorocarbon and hydrofluoroether;

nebulizing said mixture to form an aerosol of droplets of said mixture;

evaporating a majority of said carrier fluid from said aerosol;

exposing said micromechanical device to said evaporated aerosol; and

depositing said evaporated droplets of coating material on said micromechanical device.

15. The method of claim 14, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 25% by weight of said coating material.

16. The method of claim 14, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 1 part per million by weight of said coating material.

17. The method of claim 14, said evaporating comprising:

evaporating all of said carrier fluid from said aerosol.

18. The method of claim 14, comprising:

removing large droplets from said aerosol.

19. The method of claim 14, comprising:

allowing large droplets of said aerosol to settle out of said aerosol away from said micromechanical device.

20. The method of claim 14, said nebulizing comprising:

nebulizing said mixture to form an aerosol of droplets of said mixture having a mean particle diameter less than 10 microns.

21. The method of claim 14, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter less than 500 nm.

22. The method of claim 14, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter between 10 and 500 nm.

23. The method of claim 14, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a particle diameter less than 500 nm.

24. The method of claim 14, said evaporating comprising:

evaporating all of said carrier fluid from said aerosol.

25. A method of coating the surfaces of a micromechanical device, the method comprising:

mixing a coating material with a carrier fluid selected from the group consisting of perfluorocarbon and hydrofluoroether;

nebulizing said mixture to form an aerosol of droplets of said mixture;

evaporating a majority of said carrier fluid from said aerosol;

exposing said micromechanical device to said evaporated aerosol; and

depositing said evaporated droplets of coating material on said micromechanical device.

26. The method of claim 25, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 25% by weight of said coating material.

27. The method of claim 25, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 1 part per million by weight of said coating material.

28. The method of claim 25, comprising:

removing large droplets from said aerosol.

29. The method of claim 25, comprising:

allowing large droplets of said aerosol to settle out of said aerosol away from said micromechanical device.

30. The method of claim 25, said nebulizing comprising:

nebulizing said mixture to form an aerosol of droplets of said mixture having a mean particle diameter less than 10 microns.

31. The method of claim 25, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter less than 500 nm.

32. The method of claim 25, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter between 10 and 500 nm.

33. The method of claim 25, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a particle diameter less than 500 nm.

34. The method of claim 25, said evaporating comprising:

evaporating all of said carrier fluid from said aerosol.

35. A method of coating the surfaces of a micromechanical device, the method comprising:

mixing a coating material selected from the group consisting of perfluoropolyethers, fluorocarbon oligomers, perfluorinated carboxylic acids, partially fluorinated carboxylic acids, and perfluorodecanoic acid with a carrier fluid;

nebulizing said mixture to form an aerosol of droplets of said mixture;

evaporating a majority of said carrier fluid from said aerosol;

exposing said micromechanical device to said evaporated aerosol; and

depositing said evaporated droplets of coating material on said micromechanical device.

36. The method of claim 35, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 25% by weight of said coating material.

37. The method of claim 35, said mixing comprising:

mixing a coating material with a carrier fluid to obtain a mixture no more than 1 part per million by weight of said coating material.

38. The method of claim 35, said mixing comprising:

mixing a coating material with a volatile organic liquid.

39. The method of claim 35, comprising:

removing large droplets from said aerosol.

40. The method of claim 35, comprising:

allowing large droplets of said aerosol to settle out of said aerosol away from said micromechanical device.

41. The method of claim 35, said nebulizing comprising:

nebulizing said mixture to form an aerosol of droplets of said mixture having a mean particle diameter less than 10 microns.

42. The method of claim 35, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter less than 500 nm.

43. The method of claim 35, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a mean particle diameter between 10 and 500 nm.

44. The method of claim 35, said evaporating comprising:

evaporating a majority of said carrier fluid from said aerosol to leave an aerosol of droplets having a particle diameter less than 500 nm.

45. The method of claim 35, said evaporating comprising:

evaporating all of said carrier fluid from said aerosol.