Light emitting device

• US 20020070663A1
• Filed: 10/01/2001
• Published: 06/13/2002
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takahashi, Masahiro, Ogura, Keiiti
• Granted Patent: US 6,924,594 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H05B 33/04 Sealing arrangements , e.g. against humidity
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 59/874 including getter material or desiccant
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

A technique for sealing an EL panel of a light emitting device is provided. By preparing a absorption metal as a film on EL elements on the inside of an enclosed space, it becomes easy to made the interior of the space possess a absorption function, and further, an enclosure structure can be fabricated without the penetration of oxygen and moisture into the space because the absorption film is formed in succession after formation of the EL elements, according to the present invention.

Claims

1. A light emitting device comprising;

a substrate;

an EL element formed over a substrate; and

an absorption film formed over the EL element;

wherein the EL element is interposed between the substrate and the absorption film.

2. A device according to claim 1, wherein the absorption film is a hygroscopic film.

3. A device according to claim 1, wherein the absorption film comprises alkaline-earth metal.

4. A device according to claim 1, wherein the inorganic has 1 to 3 μ

m thickness.

5. A device according to claim 1, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

6. A light emitting device comprising;

a first substrate;

an EL element formed over the first substrate;

an absorption film formed over the EL element; and

a sealing substrate connected to the first substrate through a sealant;

wherein the EL element is provided in a space surrounded by the first substrate. the sealant, and the sealing substrate.

7. A device according to claim 6, wherein the absorption film is a hygroscopic film.

8. A device according to claim 6, wherein the absorption film comprises alkaline-earth metal.

9. A device according to claim 6, wherein the inorganic has 1 to 3 μ

m thickness.

10. A device according to claim 6, wherein the sealant is not overlapped with the inorganic film.

11. A device according to claim 6, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

13. A device according to claim 12, wherein the absorption film is a hygroscopic film.

14. A device according to claim 12, wherein the absorption film comprises alkaline-earth metal.

15. A device according to claim 12, wherein the inorganic has 1 to 3 μ

m thickness.

16. A device according to claim 12, wherein the absorption film is formed over the anode, and the EL layer, the cathode, and the absorption film are successively formed under an inert gas atmosphere.

17. A device according to claim 12, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

19. A device according to claim 18, wherein the absorption film is a hygroscopic film.

20. A device according to claim 18, wherein the absorption film comprises alkaline-earth metal.

21. A device according to claim 18, wherein the inorganic has 1 to 3 μ

m thickness.

22. A device according to claim 18, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

24. A device according to claim 23, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

25. A device according to claim 23, wherein the inorganic film has 1 to 3 μ

m thickness.

26. A device according to claim 23, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

28. A device according to claim 27, wherein the EL element further comprises an anode, a hole injection layer, a hole transfer layer, and a cathode.

29. The device according to claim 27, wherein the barrier film comprises a material selected from the group consisting of carbon, silicon oxide, silicon nitride, and copper phthalocyanine.

30. A device according to claim 27, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

31. A device according to claim 27, wherein the inorganic film has 1 to 3 μ

m thickness.

32. A device according to claim 27, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

54. A method of manufacturing a light emitting device according to claim 12, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

55. A method of manufacturing a light emitting device according to claim 12, wherein the inorganic film has 1 to 3 μ

m thickness.

12. A light emitting device comprising;

a substrate;

an EL element formed over the substrate, the EL element comprising an anode, an EL layer, and a cathode;

an absorption film formed over the cathode;

wherein the EL element is interposed between the substrate and the absorption film.

18. A light emitting device comprising;

a substrate;

a TFT formed over the substrate,

an EL element electrically connected with the TFT; and

an absorption film formed over the EL element;

wherein the EL element is interposed between the substrate and the absorption film.

23. A light emitting device comprising;

a substrate;

an EL element formed over a substrate; and

an inorganic hygroscopic film formed over the EL element for absorbing moisture;

wherein the EL element is enclosed by the substrate and the inorganic hygroscopic film.

27. A light emitting device comprising:

a first substrate;

an EL element comprising an organic light emitting layer formed over a substrate;

a barrier film covering the EL element;

an inorganic hygroscopic film formed over the barrier film wherein the barrier film is interposed between the inorganic hygroscopic film and the EL element.

33. A light emitting device comprising:

a first substrate;

an EL element comprising an organic light emitting layer formed over a substrate;

a barrier film covering the EL element;

an inorganic hygroscopic film formed over the barrier film wherein the barrier film is interposed between the inorganic hygroscopic film and the EL element; and

a second substrate opposed to the first substrate with the EL element disposed therebetween wherein a space between the first and second substrates are hermetically sealed by a sealant.

34. A device according to claim 33, wherein a metal film covers the sealant and the second substrate.

35. A device according to claim 34, wherein the metal film comprises a material selected from the group consisting Al and Mg.

36. A device according to claim 33, wherein the space is filled with an inert gas selected from the group consisting of nitrogen and a noble gas.

37. A device according to claim 33, wherein the EL element further comprises an anode, a hole injection layer, a hole transfer layer, and a cathode.

38. The device according to claim 33, wherein the barrier film comprises a material selected from the group consisting of carbon, silicon oxide, silicon nitride, and copper phthalocyanine.

39. A device according to claim 33, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

40. A device according to claim 33, wherein the inorganic film has 1 to 3 μ

m thickness.

41. A device according to claim 33, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

42. A light emitting device comprising:

a first substrate;

a plurality of switching elements formed over the first substrate, each of the switching elements comprising a thin film transistor;

a plurality of EL elements formed over the first substrate and operationally connected to the switching elements, each of the EL elements comprising an organic light emitting layer;

a driver circuit comprising thin film transistors formed over the first substrate;

an inorganic hygroscopic film formed over the plurality of EL elements and the driver circuit; and

a second substrate opposed to the first substrate with the EL element disposed therebetween wherein a space between the first and second substrates are hermetically sealed by a sealant.

43. A device according to claim 42, wherein a metal film covers the sealant and the second substrate.

44. A device according to claim 43, wherein the metal film comprises a material selected from the group consisting Al and Mg.

45. A device according to claim 42, wherein the space is filled with an inert gas selected from the group consisting of nitrogen and a noble gas.

46. A device according to claim 42, wherein the EL element further comprises an anode, a hole injection layer, a hole transfer layer, and a cathode.

47. A device according to claim 42, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

48. A device according to claim 42, wherein the inorganic film has 1 to 3 μ

m thickness.

49. A device according to claim 42, wherein the device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation system, an audio apparatus, a note type personal computer, a game apparatus, a portable apparatus, and an image play back device equipped with a recording medium.

50. A method of manufacturing a light emitting device comprising the steps of:

providing a film formation apparatus;

forming an EL layer over a substrate in the film formation apparatus;

forming an inorganic hygroscopic film over the EL layer in the film formation apparatus;

wherein the substrate is prevented from contacting an air outside of the film formation apparatus after the formation of the EL layer and until the formation of the inorganic hygroscopic film is finished.

51. A method of manufacturing a light emitting device according to claim 50, wherein the inorganic hygroscopic film comprises alkaline-earth metal.

52. A method of manufacturing a light emitting device according to claim 50, wherein the inorganic film has 1 to 3 μ

m thickness.

53. A method of manufacturing a light emitting device comprising the steps of:

providing a film formation apparatus having a plurality of chambers;

forming an EL layer over a substrate in one chamber of the film formation apparatus;

forming an inorganic hygroscopic film over the EL layer in an another chamber of the film formation apparatus;

wherein the steps from forming the EL layer to forming the inorganic hygroscopic film are performed without exposing the substrate to moisture and oxygen.