Desiccant for top-emitting oled

• US 20060022592A1
• Filed: 07/27/2004
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Boroson, Michael L.
• Granted Patent: US 7,316,756 B2
• Time in Patent Office: Days
• US Class Current: 313/512
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/841 Self-supporting sealing arrangements
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 59/871 Self-supporting sealing arrangements
• CPC Class Codes: H10K 59/874 including getter material or desiccant
• CPC Class Codes: H10K 71/851 Division of substrate
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/351 Metal complexes comprising lanthanides or actinides, e.g. comprising europium
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/649 Aromatic compounds comprising a hetero atom
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing

Abstract

A method for reducing moisture contamination in a top-emitting OLED device includes providing a substrate having top and bottom surfaces; forming a top-emitting EL unit over the top surface of the substrate, wherein the EL unit produces light that is primarily not emitted through the substrate; forming first and second protective covers over the top and bottom surfaces of the substrate, respectively, and thereby defining first and second chambers, respectively; providing moisture-absorbing material in association with the second chamber; and providing communication between the first and second chambers whereby moisture in the first or second chambers is absorbed by the moisture-absorbing material.

Claims

1. A method for reducing moisture contamination in a top-emitting OLED device comprising:

a) providing a substrate having top and bottom surfaces;

b) forming a top-emitting EL unit over the top surface of the substrate, wherein the EL unit produces light that is primarily not emitted through the substrate;

c) forming first and second protective covers over the top and bottom surfaces of the substrate, respectively, and thereby defining first and second chambers, respectively;

d) providing moisture-absorbing material in association with the second chamber; and

e) providing communication between the first and second chambers whereby moisture in the first or second chambers is absorbed by the moisture-absorbing material.

2. The method of claim 1 wherein the communication between the first and second chambers is provided by forming a passage through the substrate.

3. The method of claim 1 wherein the communication between the first and second chambers is provided by forming a passage around at least a part of at least one edge of the substrate.

4. The method of claim 1 wherein a single protective material that can be folded provides the first and second protective covers and also provides the communication between the first and second chambers.

5. The method of claim 1 wherein the substrate or a portion thereof is permeable to moisture either in the vapor form or in the liquid form and thereby provides the communication between the first and second chambers.

6. The method of claim 1 wherein a tube connector provides the communication between the first and second chambers.

7. The method of claim 1 wherein the moisture-absorbing material is selected from the group consisting of alkali metals;

alkaline earth metals;

other moisture-reactive metals;

alkaline metal oxides;

alkaline earth metal oxides;

sulfates;

metal halides;

perchlorates;

molecular sieves;

organometallic compounds of the type;

8. The method of claim 7 wherein the moisture-absorbing material is provided on or in the second protective cover.

9. The method of claim 7 wherein the moisture-absorbing material is provided on the substrate.

10. The method of claim 1 further including providing a protection layer on the EL unit prior to forming the first protective cover over the top surface of the substrate.

11. The encapsulated OLED device of claim 10 wherein the protection layer is provided over the entire sealed region.

12. The encapsulated OLED device of claim 10 wherein the protection layer contains a metal oxide, a metal nitride, a metal oxynitride, diamond-like carbon, semiconductor oxide, semiconductor nitride, or semiconductor oxynitride.

13. The encapsulated OLED device of claim 10 wherein the protection layer contains an organic compound.

14. The encapsulated OLED device of claim 12 wherein the protection layer contains aluminum oxide, silicon dioxide, silicon nitride, or silicon oxynitride.

15. The encapsulated OLED device of claim 10 wherein the protection layer contains multiple layers of organic, inorganic, or both organic and inorganic materials.

16. The encapsulated OLED device of claim 10 wherein the protection layer is provided by thermal physical vapor deposition, sputter deposition, electron beam deposition, chemical vapor deposition, plasma-enhanced chemical vapor deposition, laser-induced chemical vapor deposition, atomic layer deposition, spin coating, screen printing, or dispersing.

17. The method of claim 1 wherein the substrate includes rigid or flexible:

glass, plastic, metal, ceramic, semiconductor, metal oxide, metal nitride, metal sulfide, semiconductor oxide, semiconductor nitride, semiconductor sulfide, carbon, or combinations thereof.

18. The method of claim 1 wherein the protective covers include rigid or flexible:

glass, plastic, metal, ceramic, semiconductor, metal oxide, metal nitride, metal sulfide, semiconductor oxide, semiconductor nitride, semiconductor sulfide, carbon, or combinations thereof.

19. The method of claim 1 wherein the first protective cover includes one or more additional optically active layers.

20. The method of claim 19 wherein the one or more optically active layers includes a color filter array.

21. The method of claim 19 wherein the one or more optically active layers includes a color change module.

22. The method of claim 19 wherein the one or more optically active layers includes an anti-reflection layer.

23. The method of claim 19 wherein the one or more optically active layers includes a polarizing layer.

24. The method of claim 19 wherein the one or more optically active layers includes a light-extraction layer.

25. The method of claim 1 wherein a sealing material or other enclosing material between the protective covers and the substrate define a portion of the chambers.

26. The method of claim 25 wherein the sealing material is organic or a combination of organic and inorganic.

27. The method of claim 26 wherein the organic sealing material is selected from the group consisting of epoxies, polyurethanes, acrylates, silicones, polyamides, polyolefins, and polyesters, or combinations thereof.

28. The method of claim 25 wherein the sealing material is selected from the group consisting of glass, ceramic, metal, semiconductor, metal oxide, semiconductor oxide, and metal solder, or combinations thereof.

29. The method of claim 25 wherein the sealing material is bonded between the protective cover and the substrate and wherein the bonding step is accomplished by pressing, melting and cooling, reaction curing, or a combination thereof.

30. The method of claim 29 wherein the reaction includes reactions resulting from heat, radiation, mixing of two or more components, exposure to ambient moisture, removal of ambient oxygen, or combinations thereof.

31. The method of claim 29 wherein the first or second protective cover or both include vent holes that are sealed with vent hole seal material after the bonding step.

32. The method of claim 29 wherein the sealing material is so placed to leave one or more gaps between the substrate and one or both protective covers such that excess gas exits through the gaps, and wherein the gaps are sealed after the bonding step.

33. The method of claim 29 wherein the sealing material is so placed to leave one or more gaps between the substrate and one or both protective covers such that excess gas exits through the gaps until the gaps are filled by spreading the sealing material.

34. The method of claim 29 wherein during the bonding step the ambient pressure is increased above the initial pressure surrounding the substrate, the protective covers, and the sealing material, to reduce the pressure difference within spaces defined between the substrate, the protective covers, and the sealing material relative to the increased ambient pressure, to thereby prevent deformation of the sealing material.

35. A method for reducing moisture contamination in top-emitting OLED devices comprising:

a) providing a substrate having top and bottom surfaces;

b) forming two or more top-emitting EL units over the top surface of the substrate, wherein each EL unit produces light that is primarily not emitted through the substrate;

c) forming one or more first and one or more second protective covers over the top and bottom surfaces of the substrate, respectively, and thereby defining two or more first and two or more second chambers, respectively;

d) providing moisture-absorbing material in association with each second chamber; and

e) providing communication between the respective first and second chambers of each EL unit whereby moisture in the first or second chambers is absorbed by the moisture-absorbing material.

36. The method of claim 35 wherein a single first protective cover is formed over the top substrate surface.

37. The method of claim 35 wherein two or more first protective covers are formed over the top substrate surface.

38. The method of claim 35 wherein a single second protective cover is formed over the bottom substrate surface.

39. The method of claim 35 wherein two or more second protective covers are formed over the bottom substrate surface.

40. The method of claim 35 further including the step of separating the top-emitting OLED devices into individual devices or groups of devices having a portion of the initial substrate.

41. The method of claim 35 wherein the communication between the first and second chambers is provided by forming passages through the substrate.

42. The method of claim 35 wherein the communication between the first and second chambers is provided by forming passages around at least a part of at least one edge of the substrate.

43. The method of claim 35 wherein the substrate is permeable to moisture either in the vapor form or in the liquid form and thereby provides the communication between the first and second chambers.

44. The method of claim 35 wherein tube connectors provide the communication between the first and second chambers.

45. The method of claim 35 wherein the moisture-absorbing material is selected from the group consisting of alkali metals;

alkaline earth metals;

other moisture-reactive metals;

alkaline metal oxides;

alkaline earth metal oxides;

sulfates;

metal halides;

perchlorates;

molecular sieves;

organometallic compounds of the type;

46. The method of claim 45 wherein the moisture-absorbing material is provided on or in the second protective cover.

47. The method of claim 45 wherein the moisture-absorbing material is provided on the substrate.

48. The method of claim 35 further including providing a protection layer on the EL units prior to forming the first protective cover over the top surface of the substrate.

49. The encapsulated OLED device of claim 48 wherein the protection layer is provided over the entire sealed region.

50. The encapsulated OLED device of claim 48 wherein the protection layer contains a metal oxide, a metal nitride, a metal oxynitride, diamond-like carbon, semiconductor oxide, semiconductor nitride, or semiconductor oxynitride.

51. The encapsulated OLED device of claim 48 wherein the protection layer contains an organic compound.

52. The encapsulated OLED device of claim 50 wherein the protection layer is aluminum oxide, silicon dioxide, silicon nitride, or silicon oxynitride.

53. The encapsulated OLED device of claim 48 wherein the protection layer contains multiple layers of organic, inorganic, or both organic and inorganic materials.

54. The encapsulated OLED device of claim 48 wherein the protection layer is provided by thermal physical vapor deposition, sputter deposition, electron beam deposition, chemical vapor deposition, plasma-enhanced chemical vapor deposition, laser-induced chemical vapor deposition, atomic layer deposition, spin coating, screen printing, or dispersing.

55. The method of claim 35 wherein the substrate includes rigid or flexible:

glass, plastic, metal, ceramic, semiconductor, metal oxide, metal nitride, metal sulfide, semiconductor oxide, semiconductor nitride, semiconductor sulfide, carbon, or combinations thereof.

56. The method of claim 35 wherein the protective covers include rigid or flexible:

glass, plastic, metal, ceramic, semiconductor, metal oxide, metal nitride, metal sulfide, semiconductor oxide, semiconductor nitride, semiconductor sulfide, carbon, or combinations thereof.

57. The method of claim 35 wherein the first protective cover includes one or more additional optically active layers.

58. The method of claim 57 wherein the one or more optically active layers includes a color filter array.

59. The method of claim 57 wherein the one or more optically active layers includes a color change module.

60. The method of claim 57 wherein the one or more optically active layers includes an anti-reflection layer.

61. The method of claim 57 wherein the one or more optically active layers includes a polarizing layer.

62. The method of claim 57 wherein the one or more optically active layers includes a light-extraction layer.

63. The method of claim 35 wherein a sealing material or other enclosing material between the protective covers and the substrate define a portion of the chambers.

64. The method of claim 63 wherein the sealing material is organic or a combination of organic and inorganic.

65. The method of claim 64 wherein the organic sealing material is selected from the group consisting of epoxies, polyurethanes, acrylates, silicones, polyamides, polyolefins, and polyesters, or combinations thereof.

66. The method of claim 63 wherein the sealing material is selected from the group consisting of glass, ceramic, metal, semiconductor, metal oxide, semiconductor oxide, and metal solder, or combinations thereof.

67. The method of claim 63 wherein the sealing material is bonded between the protective cover and the substrate and wherein the bonding step is accomplished by pressing, melting and cooling, reaction curing, or a combination thereof.

68. The method of claim 67 wherein the reaction includes reactions resulting from heat, radiation, mixing of two or more components, exposure to ambient moisture, removal of ambient oxygen, or combinations thereof.

69. The method of claim 67 wherein the first or second protective cover or both include vent holes that are sealed with vent hole seal material after the bonding step.

70. The method of claim 67 wherein the sealing material is so placed to leave one or more gaps between the substrate and one or both protective and wherein the gaps are sealed after the bonding step.

71. The method of claim 67 wherein the sealing material is so placed to leave one or more gaps between the substrate and one or both protective covers such that excess ambient gas exits through the gaps until the gaps are filled by spreading the sealing material.

72. The method of claim 67 wherein during the bonding step the ambient pressure is increased above the initial pressure surrounding the substrate, the protective covers, and the sealing material, to reduce the pressure difference within spaces defined between the substrate, the protective covers, and the sealing material relative to the increased ambient pressure, to thereby prevent deformation of the sealing material.