Organic light-emitting display device and method for manufacturing the same

• US 10,026,790 B2
• Filed: 09/24/2014
• Issued: 07/17/2018
• Est. Priority Date: 10/08/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Binn, Lee, BuYeol
• Primary Examiner(s): Malsawma, Lex
• Assistant Examiner(s): Jones, Eric W
• Application Number:
  US14/495,480
• Publication Number:
  US 20150097171A1
• Time in Patent Office: 1,392 Days
• Field of Search: 257 40, 257 49, 257 59, 438 22, 438 28, 438 34, 438 35, 438149
• CPC Class Codes: H10K 2102/3026 Top emission
• 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 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks

Abstract

An organic light-emitting display device according to one embodiment of the present disclosure includes a substrate, a thin-film transistor formed on the substrate, a planarization layer formed on the thin-film transistor, an organic light-emitting element formed on the planarization layer, the emitting element including an organic light-emitting layer and a cathode, and a lower auxiliary wiring between the organic light-emitting element and the planarization layer, the wiring electrically connected with the cathode.

Claims

1. An organic light-emitting display device comprising:

a thin-film transistor formed on a substrate;

a planarization layer on the thin-film transistor;

an organic light-emitting element on the planarization layer, the organic light-emitting element including an anode, an organic light-emitting layer, and a cathode;

a lower auxiliary wiring electrically connected to the cathode without being in direct contact with the cathode, wherein the lower auxiliary wiring is disposed between the organic light-emitting element and the planarization layer;

a separation wall above the lower auxiliary wiring and the anode, formed of an organic insulating material and configured to separate the organic light-emitting layer from an organic light-emitting layer of an adjacent sub-pixel, the separation wall having a reverse tapered shape, wherein a portion of the separation wall is above the cathode and the organic light-emitting layer of the organic light-emitting element; and

a transparent conductive layer directly on the cathode and covering the separation wall, the transparent conductive layer electrically connecting the lower auxiliary wiring and the cathode.

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

an additional insulating layer between the lower auxiliary wiring and the organic light-emitting element.

3. The organic light-emitting display device according to claim 2, further comprising:

an upper auxiliary wiring on the additional insulating layer electrically connected to the lower auxiliary wiring and the cathode.

4. The organic light-emitting display device according to claim 3, wherein the upper auxiliary wiring is on a same plane with the anode.

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

a connection member on the planarization layer electrically connected to the thin-film transistor and the anode.

6. The organic light-emitting display device according to claim 5, wherein the connection member is on a same plane with the lower auxiliary wiring.

7. The organic light-emitting display device according to claim 1, wherein the organic light-emitting display device includes a light-emitting area that entirely overlaps with the lower auxiliary wiring such that the light-emitting area is within an area of the lower auxiliary wiring.

8. The organic light-emitting display device according to claim 7, further comprising:

bank layers on the anode defining the light-emitting area.

9. The organic light-emitting display device according to claim 8, wherein the thin-film transistor is electrically connected to the anode via a contact-hole of the planarization layer, and one of the bank layers covers the contact-hole.

10. The organic light-emitting display device according to claim 7, wherein the lower auxiliary wiring is not formed in a light-transmitting area.

11. The organic light-emitting display device according to claim 1, wherein the organic light-emitting element emits light through the cathode.

12. The organic light-emitting display device according to claim 1, wherein the lower auxiliary wiring is on a top surface of the planarization layer such that the lower auxiliary wiring is planar.

13. An organic light-emitting display device comprising:

a thin-film transistor on a substrate;

a planarization layer on the thin-film transistor including a gate electrode, a first electrode and a second electrode;

an organic light-emitting element on the planarization layer, the organic light-emitting element including an anode, an organic light-emitting layer, and a cathode; and

an auxiliary wiring over the thin-film transistor and between the planarization layer and the anode of organic light-emitting element, the auxiliary wiring being electrically connected to the cathode,

a separation wall above the auxiliary wiring and the anode, formed of an organic insulating material and configured to separate the organic light-emitting layer from an organic light-emitting layer of an adjacent sub-pixel, the separation wall having a reverse tapered shape, wherein a portion of the separation wall is above the cathode and the organic light-emitting layer of the organic light-emitting element; and

a connection member on the planarization layer electrically connected to one of the first electrode or the second electrode of the thin-film transistor and the anode, wherein the planarization layer has a thickness such that a parasitic capacitance between the thin-film transistor and the auxiliary wiring is 0.1 fF or less per unit area, and wherein the planarization layer is formed of one or more materials of a polyacrylates resin, an epoxy resin, a phenolic resin, a polyamides resin, a polyimides resin, an unsaturated polyesters resin, a poly-phenylenethers resin, a poly-phenylenesulfides resin, or benzocyclobutene, and wherein the connection member has an upper portion on a same plane with the auxiliary wiring.

14. The organic light-emitting display device according to claim 13, wherein the auxiliary wiring is configured to allow the parasitic capacitance generated between the auxiliary wiring and the thin-film transistor to be lower than a parasitic capacitance of a structure having the auxiliary wiring formed under the top surface of the planarization layer.

15. A method for manufacturing an organic light-emitting display device, comprising:

forming a thin-film transistor on a substrate;

forming a planarization layer on the thin-film transistor;

forming a lower auxiliary wiring and a connection member on the planarization layer, wherein the connection member electrically connects a source electrode or a drain electrode of the thin-film transistor and the anode, and wherein the connection member is on a same plane with the lower auxiliary wiring;

forming an additional insulating layer on the lower auxiliary wiring;

forming an anode on the additional insulating layer;

forming bank layers and a separation wall above the anode, the bank layers defining a light-emitting area that overlaps the lower auxiliary wiring and the separation wall formed in a reverse tapered shape;

forming an organic light-emitting layer and a cathode on the anode; and

forming a transparent conductive layer directly on the cathode, the transparent conductive layer electrically connecting the lower auxiliary wiring and the cathode;

wherein the lower auxiliary wiring is electrically connected with the cathode without being in direct contact with the cathode, and wherein the separation wall is formed such that a portion of the separation wall is above the cathode and the organic light-emitting layer.

16. The method according to claim 15, further comprising;

forming an upper auxiliary wiring electrically connecting the lower auxiliary wiring and the cathode, wherein the upper auxiliary wiring is formed simultaneously with the anode.

17. The method of claim 15, wherein the light-emitting area entirely overlaps with an area of the lower auxiliary wiring.

18. An organic light-emitting display device comprising:

a thin-film transistor formed on a substrate;

a planarization layer on the thin-film transistor including a gate electrode, a first electrode and a second electrode;

an organic light-emitting element on the planarization layer, the organic light-emitting element including an anode, an organic light-emitting layer, and a cathode;

a connection member on the planarization layer that is electrically connected to one of the first electrode or the second electrode of the thin-film transistor and the anode;

bank layers and a separation wall above the anode, the bank layers defining a light-emitting area of the organic light-emitting display device and the separation wall formed in a reverse tapered shape so as to sever the organic light-emitting element, wherein a portion of the separation wall is above the cathode and the organic light-emitting layer of the organic light-emitting element;

a lower auxiliary wiring electrically connected to the cathode without being in direct contact with the cathode;

an additional insulating layer between the lower auxiliary wiring and the organic light-emitting element; and

an upper auxiliary wiring on the additional insulating layer, wherein the upper auxiliary wiring electrically connects together the cathode and the lower auxiliary wiring, wherein the connection member has an upper portion on a same plane with the lower auxiliary wiring.

19. The organic light-emitting display device according to claim 18, wherein the upper auxiliary wiring is in direct contact with the lower auxiliary wiring.