Organic electroluminescent display device and fabricating method thereof

• US 20060113903A1
• Filed: 11/07/2005
• Published: 06/01/2006
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Ock-Hee
• Granted Patent: US 7,309,955 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• 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 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/8722 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass

Abstract

An electroluminescent display device includes first and second substrates facing each other and having a display area and a non-display area surrounding the display area. An array element is formed on the first substrate and an electroluminescent diode is formed on the second substrate. The electroluminescent display device further includes gate and data pad electrodes in the non-display area. The exposed portions of the gate and data pad electrodes are formed of a conductive material having a tolerance to corrosion.

Claims

1. An electroluminescent display device, comprising:

first and second substrates facing each other and having a plurality of sub-pixel regions;

a gate line on the first substrate;

a data line crossing the gate line to define the sub-pixel region on the first substrate;

an array element connected to the gate and data lines;

a connection electrode connected to the array element and disposed in the sub-pixel region;

a gate pad electrode electrically connected to the gate line and having lower and upper layers;

a data pad electrode electrically connected to the data line and having lower and upper layers, the data pad electrode disposed at the same layer as the gate pad electrode; and

an electroluminescent diode on the second substrate, wherein the upper layers of the gate and data pad electrodes have gate and data pad contact holes exposing the lower layers of the gate and data pad electrodes, respectively.

2. The device according to claim 1, wherein the lower layer is made of a conductive material having a tolerance to corrosion.

3. The device according to claim 2, wherein the lower layer includes a transparent conductive material.

4. The device according to claim 1, wherein the upper layer includes one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), molybdenum (Mo) and titanium (Ti).

5. The device according to claim 1, wherein the upper layer has a multi-layered structure.

6. The device according to claim 1, further comprising a data link line connected to the data line.

7. The device according to claim 6, further comprising a link pattern connecting the data line and the data link line, the link pattern disposed at the same layer as the connection electrode.

8. The device according to claim 7, further comprising a seal pattern for attaching the first and second substrates, wherein the link pattern is surrounded by an outline of the seal pattern.

9. The device according to claim 8, wherein a portion of the link pattern underlies the seal pattern.

10. The device according to claim 8, wherein a space between the first and second substrates surrounded by the seal pattern is under a vacuum condition or inert gas condition.

11. The device according to claim 7, further comprising a gate insulator on the gate line, and a passivation layer on the data line.

12. The device according to claim 11, wherein the gate insulator and the passivation layer have the gate and data pad contact holes along with the upper layers of the gate and data pad electrodes.

13. The device according to claim 11, wherein the passivation layer has a first link contact hole exposing the data line, and the gate insulator and the passivation layer have a second link contact hole exposing the data link line, the link pattern contacting the data line and the data link line through the first and second link contact holes, respectively.

14. The device according to claim 11, wherein the passivation layer has a drain contact hole exposing the array element, the connection electrode contacting the array element through the drain contact hole.

15. The device according to claim 1, wherein the array element includes a driving thin film transistor connected to the connection electrode and a switching thin film transistor.

16. The device according to claim 1, wherein the electroluminescent diode includes a first electrode, an emitting layer and a second electrode sequentially disposed on the second substrate.

17. The device according to claim 16, further comprising a spacer on the first electrode in the sub-pixel region, the spacer having a first height to contact a portion of the second electrode covering the spacer and the connection electrode.

18. The device according to claim 17, further comprising a separator on the first electrode between the adjacent sub-pixel regions, the separator having a second height less than the first height.

19. The device according to claim 16, wherein the second electrode includes one of alkaline metal and alkaline-earth metal.

20. The device according to claim 16, wherein the second electrode and the connection electrode are made of a conductive material having a work function lower than the first electrode.

21. The device according to claim 20, wherein the connection electrode includes one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), molybdenum (Mo) and titanium (Ti).

22. The device according to claim 20, wherein the first electrode is made of a transparent conductive material including indium-tin-oxide (ITO) and indium-zinc-oxide (IZO).

23. A method of fabricating an electroluminescent display device, comprising:

forming a gate line, a gate pad electrode at one end of the gate line and a data pad electrode on a first substrate, the gate line and the gate and data pad electrodes each having lower and upper layers;

forming a gate insulator covering the gate line and the gate and data pad electrodes;

forming a data line on the gate insulator crossing the gate line to define a sub-pixel region;

forming an array element connected to the gate and data lines;

forming a passivation layer on the array element;

forming a connection electrode on the passivation layer in the sub-pixel region;

exposing the lower layers of the gate and data pad electrodes;

forming an electroluminescent diode on a second substrate; and

attaching the first and second substrates.

24. The method according to claim 23, wherein the forming the connection electrode includes:

depositing a conductive material and a photoresist on the conductive material;

patterning the photoresist to form a photoresist pattern; and

patterning the conductive material with the photoresist pattern.

25. The method according to claim 24, wherein the exposing the lower layers of the gate and data pad electrodes includes:

patterning the passivation layer and the gate insulator to form gate and data pad contact holes exposing the upper layers of the gate and data pad electrodes before forming the connection electrode, respectively; and

etching the upper layers of the gate and data pad electrodes with the photoresist pattern after forming the connection electrode.

26. The method according to claim 25, further comprising removing the photoresist pattern after exposing the lower layers of the gate and data pad electrodes.

27. The method according to claim 23, wherein the lower layer is made of a conductive material having a tolerance to corrosion.

28. The method according to claim 27, wherein the lower layer includes a transparent conductive material.

29. The method according to claim 23, wherein the upper layer includes one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), molybdenum (Mo) and titanium (Ti).

30. The method according to claim 23, wherein the upper layer has a multi-layered structure.

31. The method according to claim 23, further comprising forming a data link line connected to the data line in the same process of forming the gate line.

32. The method according to claim 31, further comprising forming a link pattern connecting the data line and the data link line in the same process of forming the connection electrode.

33. The method according to claim 32, wherein the first and second substrates are attached with a seal pattern, and the link pattern is surrounded by an outline of the seal pattern.

34. The method according to claim 33, wherein a portion of the link pattern underlies the seal pattern.

35. The method according to claim 23, wherein the first and second substrates are attached under a vacuum condition or inert gas condition.

36. The method according to claim 32, further comprising patterning the passivation layer to form a first link contact hole exposing the data line, and patterning the passivation layer and the gate insulator to form a second link contact hole exposing the data link line, the link pattern contacting the data line and the data link line through the first and second link contact holes, respectively.

37. The method according to claim 23, further comprising patterning the passivation layer to form a drain contact hole exposing the array element, the connection electrode contacting the array element through the drain contact hole.

38. The method according to claim 23, wherein forming the array element includes forming a driving thin film transistor connected to the connection electrode and a switching thin film transistor.

39. The method according to claim 23, wherein forming the electroluminescent diode includes forming a first electrode, an emitting layer and a second electrode sequentially on the second substrate.

40. The method according to claim 39, further comprising forming a spacer in the sub-pixel region on the first electrode, the spacer having a first height to contact a portion of the second electrode covering the spacer and the connection electrode.

41. The method according to claim 40, further comprising forming a separator on the first electrode between the adjacent sub-pixel regions in the same process of forming the spacer, the separator having a second height less than the first height.

42. The method according to claim 41, wherein forming the spacer and the separator includes:

depositing an organic insulating material and a photoresist on the organic insulating material;

forming first and second photoresist patterns, the second photoresist pattern higher than the first photoresist pattern;

etching the organic insulating material with the first and second photoresist patterns to form a first organic insulating pattern below the first photoresist pattern and the spacer below the second photoresist pattern;

completely removing the first photoresist pattern and partially removing the second photoresist pattern; and

partially removing the first organic insulating pattern to form the separator.

43. The method according to claim 39, wherein the second electrodeincludes one of alkaline metal and alkaline-earth metal.

44. The method according to claim 39, wherein the second electrode and the connection electrode are made of a conductive material having a work function lower than the first electrode.

45. The method according to claim 44, wherein the connection electrode includes one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), molybdenum (Mo) and titanium (Ti).

46. The method according to claim 44, wherein the first electrode is made of a transparent conductive material including indium-tin-oxide (ITO) and indium-zinc-oxide (IZO).

47. An electroluminescent display device, comprising:

a first substrate having an array element including a gate line, a data line crossing the gate line to define a sub-pixel region, at least one thin film transistor (TFT) in the sub-pixel region, a gate pad and a data pad; and

a second substrate having an electroluminescent diode electrically connected to the TFT,

wherein the gate and data pads have a multi-layered structure and exposed portions of the gate and data pads include a conductive material having a tolerance to corrosion.

48. The device according to claim 47, wherein the conductive material is transparent.

49. The device according to claim 47, further comprising a data link line connected to the data line, and a link pattern connecting the data line and the data link line.

50. The device according to claim 49, further comprising a seal pattern for attaching the first and second substrates, wherein the link pattern is surrounded by the seal pattern.

51. The device according to claim 47, wherein the electroluminescent diode includes a first electrode, an emitting layer and a second electrode sequentially disposed on the second substrate.

52. The device according to claim 51, further comprising a spacer on the first electrode, the spacer contacting a portion of the second electrode covering the spacer.

53. The device according to claim 51, wherein the second electrode includes one of alkaline metal and alkaline-earth metal.

54. The device according to claim 47, wherein the electroluminescent diode is electrically connected to the TFT via a connection electrode.

55. The device according to claim 54, wherein the connection electrode includes one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), molybdenum (Mo) and titanium (Ti).

56. The device according to claim 51, wherein the first electrode is made of a transparent conductive material including indium-tin-oxide (ITO) and indium-zinc-oxide (IZO).