Organic light emitting display

1. An organic light emitting display comprising:

a substrate;

a driving unit formed over the substrate;

a planarization layer formed over the driving unit, the planarization layer comprising a normal tapered edge portion;

an emission unit formed over the planarization layer to be electrically connected to the driving unit; and

a passivation layer formed over the planarization layer to cover the emission unit and the planarization layer,

wherein the tapered edge portion of the planarization layer is in contact with the passivation layer.

2. The organic light emitting display of claim 1 , wherein a taper angle of the edge portion of the planarization layer is about 15 degrees to 60 degrees.

3. The organic light emitting display of claim 1 , wherein a taper angle of the edge portion of the planarization layer is about 15 degrees to 30 degrees.

4. The organic light emitting display of claim 1 , wherein the planarization layer comprises one selected from a group consisting of a poly acryl-based resin, a polyimide-based resin, a benzocyclobutene-based resin, and a spin on glass (SOG).

5. The organic light emitting display of claim 1 , wherein the passivation layer comprises a normal tapered edge portion, wherein a taper angle of the edge portion of the passivation layer is about 15 degrees to 60 degrees.

6. The organic light emitting display of claim 5 , wherein the taper angle of the edge portion of the passivation layer is about 15 degrees to 30 degrees.

7. The organic light emitting display of claim 5 , wherein a taper angle of the edge portion of the passivation layer is substantially the same as a taper angle of the edge portion of the planarization layer.

8. The organic light emitting display of claim 5 , wherein a taper angle of the edge portion of the passivation layer is less than a taper angle of the edge portion of the planarization layer.

9. The organic light emitting display of claim 1 , wherein the driving unit comprises at least a thin film transistor, wherein the thin film transistor comprises an active layer comprising amorphous silicon.

10. The organic light emitting display of claim 1 , wherein the emission unit comprises a first electrode, an organic emitting layer and a second electrode.

11. The organic light emitting display of claim 10 , wherein the first electrode is an anode comprising a metal layer and a transparent conductive oxide layer having a high work function.

12. The organic light emitting display of claim 11 , wherein the transparent oxide layer comprises one selected from a group consisting of ITO, IZO, ICO and ZnO.

13. The organic light emitting display of claim 11 , wherein the second electrode is a cathode and a transflective electrode comprising a metal having a low work function.

14. The organic light emitting display of claim 13 , wherein the metal comprises one selected from a group consisting of Mg, Ag, Al, Ca and an alloy thereof.

15. The organic light emitting display of claim 10 , wherein the first electrode is a cathode comprising a metal having a low work function.

16. The organic light emitting display of claim 15 , wherein the second electrode is an anode comprising a transparent conductive oxide layer having a high work function.

17. The organic light emitting display of claim 1 , further comprising a cover substrate attached to the substrate with a sealant.

18. The organic light emitting display of claim 17 , wherein the cover substrate is a transparent substrate comprising glass or plastic.

19. The organic light emitting display of claim 17 , wherein the sealant comprises a normal tapered edge portion.

20. The organic light emitting display of claim 1 , wherein the tapered edge portion of the planarization layer contacts an area separated from the emission unit.

21. The organic light emitting display of claim 20 , wherein the tapered edge portion of the planarization layer is located at a terminal end of the planarization layer that is not in contact with the emission unit.

22. The organic light emitting display of claim 1 , wherein the tapered edge portion of the planarization layer slants away from the driving unit.

23. The organic light emitting display of claim 1 , wherein the passivation layer has a tapered edge portion that contacts the tapered edge portion of the planarization layer.

24. The organic light emitting display of claim 23 , wherein the edge portions of the passivation layer and the planarization layer taper at substantially the same angle.

25. The organic light emitting display of claim 23 , wherein the edge portions of the passivation layer and the planarization layer taper at different angles.

26. The organic light emitting display of claim 1 , further comprising:

a sealant formed over the passivation and planarization layers,

wherein the sealant has an edge portion that tapers at a different angle than the tapered edge portions of the passivation and planarization layers.

27. The organic light emitting display of claim 1 , wherein the tapered edge portion of the planarization layer is located between terminal ends of a cover substrate and a base substrate, the emission unit located between the cover and base substrates.

28. The organic light emitting display of claim 1 , wherein the tapered edge portion of the planarization layer is located between an end of an electrode of the emission unit and a barrier rib.

29. An organic light emitting display comprising:

a substrate;

a driving unit on the substrate;

a planarization layer, on the driving unit, having a tapered edge portion;

an emission unit on the planarization layer to electrically couple with the driving unit; and

a passivation layer on the planarization layer to cover the emission unit and the planarization layer,

wherein the tapered edge portion of the planarization layer contacts the passivation layer.

30. The organic light emitting display of claim 29 , wherein a taper angle of the edge portion of the planarization layer is approximately 15 degrees to 60 degrees.