Display device and manufacturing method thereof

• US 6,724,150 B2
• Filed: 01/31/2002
• Issued: 04/20/2004
• Est. Priority Date: 02/01/2001
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Maruyama, Junya, Yamazaki, Shunpei
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): A, Minh D
• Application Number:
  US10/062,294
• Publication Number:
  US 20020149320A1
• Time in Patent Office: 810 Days
• Field of Search: 315/169.1, 315/169.3, 315/169.4, 313/504, 313/506, 313/512
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/841 Self-supporting sealing arrangements
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/127 comprising two substrates, e.g. display comprising OLED array and TFT driving circuitry on different substrates
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 77/10 Substrates, e.g. flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

In a display device using an organic light emitting diode (OLED), the occurrence of a dark spot and peeling of a cathode due to moisture are suppressed. An outer edge portion of a sealing substrate (second substrate) (102) is made to have a convex shape and a gap between the sealing substrate and an element substrate are controlled by means of this convex region. Thus, since it is not required that a layer (106) having adhesion for bonding together the sealing substrate and the element substrate has a function for controlling the gap, the thickness of the layer can be minimized. Therefore, the amount of moisture which is transmitted through the layer (having adhesion) made of an organic material and penetrated in a sealed region can be reduced.

Claims

1. A display device comprising:

a first substrate;

an organic light emitting element over the first substrate; and

a second substrate which is translucent, the second substrate bonded to the first substrate through a layer having adhesion,

wherein a surface of the second substrate opposing the first substrate comprises a first thickness at a first region and a second thickness at a second region, the first region is adhered with the layer having adhesion, and the second region is located inside the first region and concaved relative to the first region.

2. A display device according to claim 1, wherein the first substrate is a glass substrate.

3. A display device according to claim 1, wherein the first substrate and the second substrate are a glass substrate.

4. A display device according to claim 1, wherein a thickness of the layer having adhesion is 10 μ

m or less.

5. A display device according to claim 1, wherein the display device is an active matrix display device.

6. A display device according to claim 1, wherein the display device is a passive matrix display device.

7. A display device comprising;

a first substrate;

an organic light emitting element over the first substrate; and

a second substrate which is translucent, the second substrate bonded to the first substrate through a layer having adhesion,

wherein a surface of the second substrate opposing the first substrate comprises a first region, a second region, and a third region, the first region is adhered with the layer having adhesion, the second region is located inside the first region and concaved relative to the first region, the third region is located inside the second region and concaved relative to the second region, and

wherein a dry agent is provided in the third region.

8. A display device according to claim 7, wherein a permeable film is adhered to a portion of the second region to thereby contain the dry agent in the third region.

9. A display device according to claim 8, wherein the permeable film is provided so that a bottom surface of the permeable film is not contact with the first substrate.

10. A display device according to claim 8, wherein a difference in height between a bottom portion of the second region which is concaved relative to the first region and the first region is 160 μ

m to 350 μ

m.

11. A display device according to claim 7, wherein a difference in height between a bottom portion of the second region which is concaved relative to the first region and the first region is 10 μ

m to 50 μ

m.

12. A display device according to claim 7, wherein a difference in heioht between a bottom portion of the third region which is concaved relative to the second region and the second region is 50 μ

m to 150 μ

m.

13. A display device according to claim 7, wherein the first substrate is a glass substrate.

14. A display device according to claim 7, wherein the first substrate and the second substrate are a glass substrate.

15. A display device according to claim 7, wherein a thickness of the layer having adhesion is 10 μ

m or less.

16. A display device according to claim 7, wherein the display device is an active matrix display device.

17. A display device according to claim 7, wherein the display device is a passive matrix display device.

18. A display device comprising:

a first substrate;

an organic light emitting element over the first substrate;

a layer having adhesion for enclosing with a gap an area surrounding a region in which the organic light emitting element is provided on the first substrate; and

a second substrate which is translucent, the second substrate bonded to the first substrate through the layer having adhesion,

wherein a surface of the second substrate opposing the first substrate comprises a first region, a second region, and a third region, the first region is adhered with the layer having adhesion, the second region is surrounded by the first region and concaved relative to the first region, the third region is located between the layer having adhesion and an upper portion of the region in which the organic light emitting element is provided and concaved relative to the second region, and

wherein a dry agent is located in the third region.

19. A display device according to claim 18, wherein a permeable film is provided between the layer having adhesion and the upper portion of the region in which the organic light emitting element is provided, and the permeable film is adhered to a part of the second region to thereby contain the agent in the third region.

20. A display device according to claim 19, wherein the permeable film is provided so that a bottom surface of the permeable film is not contact with the first substrate.

21. A display device according to claim 19, wherein a difference in height between a bottom portion of the second region which is concaved relative to the first region and the first region is 160 μ

m to 350 μ

m.

22. A display device according to claim 18, wherein a difference in height between a bottom portion of the second region which is concaved relative to the first region and the first region is 10 μ

m to 50 μ

m.

23. A display device according to claim 18, wherein a difference in height between a bottom portion of the third region which is concaved relative to the second region and the second region is 50 μ

m to 150 μ

m.

24. A display device according to claim 18, wherein the first substrate is a glass substrate.

25. A display device according to claim 18, wherein the first substrate and the second substrate are a glass substrate.

26. A display device according to claim 18, wherein a thickness of the layer having adhesion is 10 μ

m or less.

27. A display device according to claim 18, wherein the display device is an active matrix display device.

28. A display device according to claim 18, wherein the display device is a passive matrix display device.

29. A passive matrix display device comprising:

a first substrate;

an organic light emitting element over the first substrate; and

a second substrate which is translucent, the second substrate is bonded to the first substrate through a layer having adhesion,

wherein minute unevennesses are formed on a surface of the second substrate.

30. A passive matrix display device according to claim 29, wherein height of the minute unevennesses are set to be 0.1 μ

m to 3 μ

m.

31. A display device according to claim 29, wherein the first substrate is a glass substrate.

32. A display device according to claim 29, wherein the first substrate and the second substrate are a glass substrate.

33. A display device according to claim 29, wherein a thickness of the layer having adhesion is 10 μ

m or less.

34. An active matrix display device comprising:

a first substrate;

at least one thin film transistor over the first substrate;

an insulating film over the thin film transistor;

an organic light emitting element over the insulating film; and

a second substrate which is translucent, the second substrate bonded to the first substrate through a layer having adhesion,

wherein minute unevennesses are formed on a surface of the second substrate.

35. A passive matrix display device according to claim 34, wherein height of the minute unevennesses are set to be 0.1 μ

m to 3 μ

m.

36. A display device according to claim 34, wherein the first substrate is a glass substrate.

37. A display device according to claim 34, wherein the first substrate and the second substrate are a glass substrate.

38. A display device according to claim 34, wherein a thickness of the layer having adhesion is 10 μ

m or less.

39. A method of manufacturing a display device in which a first substrate on which an organic light emitting element is provided and a second substrate bonded to the first substrate through a layer having adhesion, the method comprising:

providing a first mask in at least a first region to which the layer having adhesion is adhered;

first digging the second substrate by an abrasive machining method to form a second region which is concaved relative to the first region;

removing the first mask;

providing a second mask at least in a region where the first mask is provided and in a region located above a region where the organic light emitting element is provided;

second digging the second substrate by an abrasive machining method to thereby form a third region which is concaved relative to the second region; and

providing a dry agent in the third region.

40. A method of manufacturing a display device according to claim 39, further comprising a step of providing a permeable film in the second and the third region after the providing a dry agent in the third region.

41. A method of manufacturing a display device according to claim 40, wherein a first digging depth is larger than a thickness of the permeable film.

42. A method of manufacturing a display device according to claim 41, wherein the first digging depth is 160 μ

m to 350 μ

m.

43. A method of manufacturing a display device according to claim 40, further comprising after the providing the permeable film:

bonding the first substrate and the second substrate together through the layer having adhesion; and

cutting the first substrate and the second substrate by a gas laser.

44. A method of manufacturing a display device according to claim 43, wherein the gas laser is a CO₂ laser.

45. A method of manufacturing a display device according to claim 39, wherein a first digging depth is 10 μ

m to 50 μ

m.

46. A method of manufacturing a display device according to claim 39, wherein a second digging depth is 50 μ

m to 150 μ

m.

47. A method of manufacturing a display device according to claim 39, further comprising:

bonding the first substrate and the second substrate together through the layer having adhesion after the providing a dry agent in the third region; and

cutting the first substrate and the second substrate by a gas laser.

48. A method of manufacturing a display device according to claim 47, wherein the gas laser is a CO₂ laser.