Organic light emitting display

1. An organic light emitting display comprising:

a substrate;

a thin film transistor positioned on the substrate;

a planarization layer positioned on the thin film transistor;

an emission unit positioned on the planarization layer and electrically connected to the thin film transistor;

a passivation layer positioned on the substrate to cover the thin film transistor, the emission unit and an edge portion of the planarization layer; and

a cover substrate attached to the substrate, wherein the substrate is attached to the cover substrate with a sealant,

wherein the sealant is positioned in a space between the substrate and the cover substrate to cover an edge portion of the passivation layer, and

wherein the planarization layer, the passivation layer, and the sealant each have a normal taper edge portion, and taper angles of the edge portions of the planarization layer, the passivation layer, and the sealant range from 15° to 60°, respectively.

2. The organic light emitting display of claim 1 , wherein a length ranging from an edge of the planarization layer to an edge of the passivation layer ranges from 50 μm to 500 μm.

3. The organic light emitting display of claim 1 , wherein the planarization layer and the passivation layer each have a normal taper edge portion, and taper angles of the edge portions of the planarization layer and the passivation layer range from 15° to 60°, respectively.

4. The organic light emitting display of claim 3 , wherein the taper angle of the edge portion of the planarization layer is substantially equal to the taper angle of the edge portion of the passivation layer.

5. The organic light emitting display of claim 1 , wherein the sealant is positioned in the portions of the substrate and the cover substrate, and is spaced from the passivation layer.

6. The organic light emitting display of claim 1 , wherein the taper angles of the edge portions of the planarization layer, the passivation layer, and the sealant are substantially equal to one another.

7. The organic light emitting display of claim 1 , wherein the cover substrate is a transparent substrate comprising glass or plastic.

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

9. The organic light emitting display of claim 8 , wherein the first electrode is a cathode, and comprises a metal having a low work function.

10. The organic light emitting display of claim 9 , wherein the second electrode is an anode, and comprises a transparent conductive oxide layer having a high work function.

11. The organic light emitting display of claim 8 , wherein the first electrode is an anode, and comprises a reflective 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 conductive 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 having a low work function.

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

15. The organic light emitting display of claim 1 , wherein the planarization layer comprises one of a polyacryl-based resin, a polyimide-based resin, and a benzocyclobutene (BCB)-based resin.

16. The organic light emitting display of claim 1 , wherein the passivation layer comprises a silicon oxide layer or a silicon nitride layer.