Getter for enhanced micromechanical device performance

• US 6,843,936 B1
• Filed: 10/13/1999
• Issued: 01/18/2005
• Est. Priority Date: 10/22/1998
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Jacobs, Simon Joshua
• Primary Examiner(s): THEXTON, MATTHEW
• Application Number:
  US09/416,910
• Time in Patent Office: 1,924 Days
• Field of Search: 252/194, 252/190
• US Class Current: 252/194
• CPC Class Codes: B01D 53/28 Selection of materials for use as drying agents

Abstract

A desiccant compound, image projection system using the desiccant compound, and a method for utilizing the desiccant compound. The desiccant compound formed by mixing (202) a polymer binder selected from the group consisting of polysaccharides (including without limitation structural polysaccharides such as cellulose, chitin, and their functionalized derivatives), polyamines, polysulfones, and polyamides with a drying agent, typically a zeolite, at a polymer to drying agent weight ratio of 1:2.1 to 1:100, or 1:4 to 1:10. After the desiccant compound is mixed (202) it is applied (204) to a surface and cured (206), often through the application of heat and vacuum. The cured desiccant compound is conditioned (208) and the it package is sealed (210).

Claims

1. A desiccant comprising:

a polymer binder selected from the group consisting of poly(vinylpyrrolidone), poly(2-vinylpyridine), poly(4-vinylpyridine), and copolymers of 2-vinylpyridine and 4-vinylpyridine;

a drying agent dispersed in said binder; and

said polymer to drying agent weight ratio being 1;

2.1 to 1;

100.

2. The desiccant of claim 1, wherein said drying agent is a molecular sieve.

3. The desiccant of claim 1, wherein said drying agent is a zeolite.

4. The desiccant of claim 1, said polymer to said drying agent weight ratio being 1:

4 to 1;

10.

5. The desiccant of claim 1, further comprising:

a solvent, said polymer and said drying agent to solvent weight ratio being 2;

1 to 1;

100.

6. The desiccant of claim 1, said desiccant able to reversibly absorb a carboxylic passivation material.

7. A desiccant comprising:

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides;

a drying agent dispersed in said binder;

a carboxylic acid passivation material, said carboxylic acid passivation material absorbed by said polymer; and

said polymer to drying agent weight ratio being 1;

2.1 to 1;

100.

8. The desiccant of claim 7, wherein said polymer is a structural a polysaccharide.

9. The desiccant of claim 7, wherein said polymer is selected from the group consisting of cellulose, hydroxypropylcellulose, chitin, and their functional derivatives.

10. The desiccant of claim 7, wherein said polymer is poly(vinylpyrrolidone).

11. The desiccant of claim 7, wherein said polymer is selected from the group consisting of poly(2-vinylpyridine), poly(4-vinylpyridine), and copolymers of 2-vinylpyridine and 4-vinylpyridine.

12. The desiccant of claim 7;

wherein said carboxylic acid passivation material is a perfluoroalkanoic acid.

13. The desiccant of claim 7, wherein said carboxylic acid passivation material is perfluorodecanoic acid.

14. The desiccant of claim 7, said desiccant able to reversibly absorb a carboxylic passivation material.

15. A device comprising:

a micromechanical machine;

a package enclosing said micromechanical machine; and

a desiccant enclosed by said package, said desiccant comprising;

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides;

a drying agent dispersed in said binder; and

said polymer to drying agent weight ratio being 1;

2.1 to 1;

100.

16. The device of claim 15, wherein said drying agent is a molecular sieve.

17. The device of claim 15, wherein said drying agent is a zeolite.

18. The device of claim 15, said polymer to said drying agent weight ratio being 1:

4 to 1;

10.

19. The device of claim 15, further comprising:

a solvent, said polymer and said drying agent to solvent weight ratio being 2;

1 to 1;

100.

20. The device of claim 15, wherein said polymer is a structural polysaccharide.

21. The device of claim 15, wherein said polymer is selected from the group consisting of cellulose, hydroxypropylcellulose, chitin, and their functional derivatives.

22. The device of claim 15, wherein said polymer is poly(vinylpyrrolidone).

23. The device of claim 15, wherein said polymer is selected from the group consisting of poly(2-vinylpyridine), poly(4 vinylpyridine), and copolymers of 2-vinylpyridine and 4-vinylpyridine.

24. The device of claim 15, further comprising:

a carboxylic acid passivation material, said carboxylic acid passivation material absorbed by said polymer.

25. The device of claim 24, wherein said carboxylic acid passivation material is a perfluoroalkanoic acid.

26. The device of claim 24, wherein said carboxylic acid passivation material is perfluorodecanoic acid.

27. The device of claim 15, said desiccant able to reversibly absorb a carboxylic passivation material.

28. A method of applying a desiccant, said method comprising the steps of:

mixing said desiccant, said mixing comprising mixing;

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides; and

a drying agent dispersed in said binder, said polymer to drying agent weight ratio being 1;

2.1 to 1;

100;

applying said desiccant to a surface; and

curing said desiccant.

29. The method of claim 28, further comprising the step of:

conditioning said desiccant by allowing said desiccant to absorb a carboxylic acid passivation material.

30. The method of claim 28, further comprising the step of:

conditioning said desiccant by allowing said desiccant to absorb a perfluoroalkanoic acid passivation material.

31. The method of claim 28, further comprising the step of:

conditioning said desiccant by allowing said desiccant to absorb a perfluorodecanoic acid passivation material.

32. The method of claim 28, said curing step comprising heating said desiccant in the presence of a vacuum.

33. The method of claim 29, said conditioning step comprising heating said desiccant in the presence of a vacuum.

34. The method of claim 29, said conditioning step comprising the steps of:

heating said desiccant in the presence of a vacuum; and

exposing said desiccant to said carboxylic acid passivation material.

35. The method of claim 29, said conditioning step comprising the steps of:

heating said desiccant in the presence of a vacuum; and

depositing said carboxylic acid passivation material in solid form directly in a package; and

sealing said package; and

heating said package so that said carboxylic acid passivation material is absorbed into said desiccant.

36. The method of claim 28, said mixing step comprising the step of mixing:

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides;

a drying agent dispersed in said binder, said polymer to drying agent weight ratio being 1;

2.1 to 1;

100; and

a solvent, wherein said polymer and said drying agent to solvent weight ratio is 2;

1 to 1;

100.

37. The method of claim 28, said mixing step comprising the step of mixing:

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides;

a drying agent dispersed in said binder, said polymer to drying agent weight ratio being 1;

2.1 to 1;

100; and

a solvent, wherein said polymer and said drying agent to solvent weight ratio is 1;

1 to 1;

10.

38. The method of claim 28, said mixing step comprising the step of mixing:

as polysaccharide; and

a drying agent dispersed in said binder, said structural polysaccharide to drying agent weight ratio being 1;

2.1 to 1;

100.

39. The method of claim 28, said mixing step comprising the step of mixing:

a polymer selected from the group consisting of cellulose, hydroxypropylcellulose, chitin, and their functional derivatives; and

a drying agent dispersed in said binder, said polymer to drying agent weight ratio being 1;

2.1 to 1;

100.

40. The method of claim 28, said mixing step comprising the step of mixing:

poly(vinylpyrrolidone); and

a drying agent dispersed in said binder, said poly(vinylpyrrolidone) to drying agent weight ratio being 1;

2.1 to 1;

100.

41. The method of claim 28, said mixing step comprising the step of mixing:

a polymer selected from the group consisting of poly(2-vinylpyridine), poly(4-vinylpyridine), and copolymers of 2-vinylpyridine and 4-vinylpyridine; and

a drying agent dispersed in said binder, said polymer to drying agent weight ratio being 1;

2.1 to 1;

100.

42. An image projection system comprising:

a light source providing a beam of light along a light path;

a micromirror on said light path, said micromirror device selectively reflecting portions of said beam of light in response to image data and control signals, said micromirror device comprising;

a micromechanical machine;

a package enclosing said micromechanical machine; and

a desiccant enclosed by said package, said desiccant comprising;

a polymer binder selected from the group consisting of polysaccharides, polyamines, and polyamides;

a drying agent dispersed in said binder; and

wherein said polymer to drying agent weight ratio is 1;

2.1 to 1;

100 projection optics receiving said selectively reflected portions of said beam of light and focusing said selectively reflected portions of said beam of light onto an image plane.

43. The image projection system of claim 42, wherein said drying agent is a molecular sieve.

44. The image projection system of claim 42, wherein said drying agent is a zeolite.

45. The image projection system of claim 42, said polymer to said drying agent weight ratio being 1:

4 to 1;

10.

46. The image projection system of claim 42, wherein said polymer is a structural polysaccharide.

47. The image projection system of claim 42, wherein said polymer is selected from the group consisting of cellulose, hydroxypropylcellulose, chitin, and their functional derivatives.

48. The image projection system of claim 42, wherein said polymer is poly(vinylpyrrolidone).

49. The image projection system of claim 42, wherein said polymer is selected from the group consisting of poly(2-vinylpyridine), poly(4-vinylpyridine), and copolymers of 2-vinylpyridine and 4-vinylpyridine.

50. The image projection system of claim 42, said desiccant able to reversibly absorb a carboxylic passivation material.

51. The image projection system of claim 42, further comprising:

a carboxylic acid passivation material, said carboxylic acid passivation material absorbed by said polymer.

52. The image projection system of claim 51, wherein said carboxylic acid passivation material is a perfluoroalkanoic acid.

53. The image projection system of claim 51, wherein said carboxylic acid passivation material is perfluorodecanoic acid.