ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20160043341A1
• Filed: 08/04/2015
• Published: 02/11/2016
• Est. Priority Date: 08/05/2014
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: HEO, JoonYoung, PANG, HeeSuk
• Granted Patent: US 9,570,471 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H10K 50/824 combined with auxiliary electrodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/1315 comprising structures specially adapted for lowering the resistance
• CPC Class Codes: H10K 59/80522 combined with auxiliary electrodes
• CPC Class Codes: H10K 59/80524 Transparent cathodes, e.g. comprising thin metal layers

Abstract

Provided is an organic light emitting display device including: a substrate; a first anode and a second anode formed on the substrate; a first auxiliary electrode formed between the first anode and the second anode; a first organic light emitting layer and a second organic light emitting layer; a first bank including an undercut formed on an upper part of a first edge of the first auxiliary electrode; a second bank including an undercut formed on an upper part of a second edge of the first auxiliary electrode; a second auxiliary electrode disposed between the undercut of the first bank and the first auxiliary electrode; a third auxiliary electrode disposed between the undercut of the second bank and the first auxiliary electrode; a first cathode electrically connected with the second auxiliary electrode; and a second cathode electrically connected with the third auxiliary electrode.

Claims

1. An organic light emitting display device comprising:

a substrate;

a first anode and a second anode formed on the substrate;

a first auxiliary electrode formed between the first anode and the second anode;

a first organic light emitting layer and a second organic light emitting layer respectively formed on the first anode and the second anode;

a first bank formed to cover an edge of the first anode and including an undercut formed on an upper part of a first edge of the first auxiliary electrode;

a second bank formed to cover an edge of the second anode and including an undercut formed on an upper part of a second edge of the first auxiliary electrode;

a second auxiliary electrode disposed between the undercut of the first bank and the first auxiliary electrode;

a third auxiliary electrode disposed between the undercut of the second bank and the first auxiliary electrode;

a first cathode formed on the first organic light emitting layer and the first bank and electrically connected with the second auxiliary electrode; and

a second cathode formed on the second organic light emitting layer and the second bank and electrically connected with the third auxiliary electrode.

2. The organic light emitting display device according to claim 1, wherein the first anode, the second anode, and the first auxiliary electrode are formed of the same material.

3. The organic light emitting display device according to claim 1, wherein the undercut of the first bank includes one side that is in contact with the first auxiliary electrode and the second auxiliary electrode, and the undercut of the second bank include one side that is in contact with the first auxiliary electrode and the third auxiliary electrode.

4. The organic light emitting display device according to claim 1, wherein the second auxiliary electrode and the third auxiliary electrode are formed of the same material.

5. The organic light emitting display device according to claim 4, wherein the second auxiliary electrode and the third auxiliary electrode are formed of a material different in etching selectivity from the first auxiliary electrode.

6. The organic light emitting display device according to claim 1, wherein each of the second auxiliary electrode and the third auxiliary electrode is formed by laminating different kinds of metals.

7. The organic light emitting display device according to claim 1, wherein the second auxiliary electrode is completely overlapped with the first bank, and the third auxiliary electrode is completely overlapped with the second bank.

8. The organic light emitting display device according to claim 1, wherein each of the first cathode and the second cathode includes a transparent conductive material.

9. The organic light emitting display device according to claim 1, wherein each of the first cathode and the second cathode is in contact with the first auxiliary electrode.

10. The organic light emitting display device according to claim 1, further comprising:

a light-blocking metal layer formed on the substrate and electrically connected with the first auxiliary electrode; and

a thin film transistor formed on the light-blocking metal layer and including an active layer formed of an oxide semiconductor.

11. An organic light emitting display device comprising:

a substrate;

a thin film transistor disposed on the substrate;

a fourth auxiliary electrode formed of the same material as at least one of electrodes constituting the thin film transistor;

a flattening layer formed to cover the thin film transistor and the fourth auxiliary electrode; and

an organic light emitting element including an anode disposed on the flattening layer, an organic light emitting layer, and a cathode, the cathode electrically connected with the fourth auxiliary electrode through a contact hole in the flattening layer so as to have a uniform electrical resistance,

wherein the contact hole includes;

an undercut configured to electrically connect the cathode with the fourth auxiliary electrode; and

an outgas reducing layer capable of minimizing a gas generated from the flattening layer.

12. The organic light emitting display device according to claim 11, wherein the flattening layer is formed of at least two layers which are respectively reactive with different etching solvents or different from each other in etching rate.

13. The organic light emitting display device according to claim 12, wherein the flattening layer further includes a passivation film and a flattening film configured to protect the thin film transistor, and the contact hole is disposed in the passivation film and the flattening film.

14. The organic light emitting display device according to claim 13, wherein the contact hole includes a first contact hole disposed in the passivation film and a second contact hole disposed in the flattening film, and

the first contact hole and the second contact hole are partially overlapped with each other so as to expose the fourth auxiliary electrode and form the undercut.

15. The organic light emitting display device according to claim 11, wherein the outgas reducing layer is formed of the same material as the anode.

16. The organic light emitting display device according to claim 15, wherein the outgas reducing layer is disposed to cover an inner surface of the contact hole.

17. A method of manufacturing an organic light emitting display device, comprising:

forming a first auxiliary electrode between a first anode and a second anode while forming the first anode and the second anode on a substrate;

forming a sacrificing layer on the first auxiliary electrode;

forming a first bank to cover an edge of the first anode and an edge of the sacrificing layer and a second bank to cover an edge of the second anode and an edge of the sacrificing layer;

forming a second auxiliary electrode between the first bank and the first auxiliary electrode and a third auxiliary electrode between the second bank and the first auxiliary electrode by etching the sacrificing layer with an etchant;

forming a first organic light emitting layer and a second organic light emitting layer respectively on the first anode and the second anode; and

forming a first cathode on the first organic light emitting layer and the first bank so as to be electrically connected with the second auxiliary electrode and a second cathode on the second organic light emitting layer and the second bank so as to be electrically connected with the third auxiliary electrode.

18. The method of manufacturing an organic light emitting display device according to claim 17, wherein the sacrificing layer is formed of a material different in etching selectivity from the first auxiliary electrode.

19. The method of manufacturing an organic light emitting display device according to claim 17, wherein forming the second auxiliary electrode and the third auxiliary electrode includes adjusting a width in a horizontal direction of each of the second auxiliary electrode and the third auxiliary electrode by adjusting an etching time of the sacrificing layer.

20. A method of manufacturing an organic light emitting display device, comprising:

forming a thin film transistor and a fourth auxiliary electrode on a substrate;

forming a thin film transistor passivation film on the thin film transistor and the fourth auxiliary electrode;

exposing the fourth auxiliary electrode by forming a first contact hole in the thin film transistor passivation film;

forming a flattening film on the thin film transistor passivation film;

exposing a part of the fourth auxiliary electrode and the thin film transistor passivation film by forming a second contact hole in the flattening film;

forming a first anode connected with the thin film transistor on the flattening film;

forming an outgas reducing layer on the second contact hole;

etching the thin film transistor passivation film exposed through the second contact hole;

forming a first organic light emitting layer on the first anode; and

forming a first cathode on the first organic light emitting layer.