ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD OF FABRICATING THE SAME

• US 20170186826A1
• Filed: 12/14/2016
• Published: 06/29/2017
• Est. Priority Date: 12/29/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: NAM, Kyoung-Jin, KIM, Jeong-Oh, KIM, Yong-Min
• Granted Patent: US 10,084,026 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• 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: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/621 Providing a shape to conductive layers, e.g. patterning or selective deposition

Abstract

Disclosed are an organic light emitting display device improving opening ratio and a method of fabricating the same. The organic light emitting display device includes a light emitting device disposed at each sub-pixel of a substrate, a pixel circuit driving the light emitting device, a bank providing a first light emitting region at a remaining region except for a region where the pixel circuit is disposed, and a second light emitting region at the region where the pixel circuit is disposed, and a color filter disposed at the first and second light emitting regions, wherein at least one of electrodes included in the pixel circuit includes a transparent conductive layer at the second light emitting region.

Claims

1. An organic light emitting display device having a plurality of sub-pixels comprising:

a light emitting device in each sub-pixel of a substrate;

a pixel circuit that drives the light emitting device;

a bank that provides a first light emitting region where the pixel circuit is not disposed and a second light emitting region where the pixel circuit is disposed; and

a color filter in the first and second light emitting regions,

wherein at least one of electrodes included in the pixel circuit includes a transparent conductive layer in the second light emitting region.

2. The organic light emitting display device according to claim 1, wherein the pixel circuit comprises:

a driving transistor connected to the light emitting device; and

a switching transistor connected to the driving transistor,

each of the driving transistor and the switching transistor comprises;

an active layer disposed on the substrate;

a gate electrode overlapping the active layer, the gate electrode being separated from the active layer by a gate insulating pattern;

a source electrode connected to the active layer; and

a drain electrode facing the active layer, the drain electrode being separated from the source electrode by the active layer, and

wherein each of the source electrode and the drain electrode includes the transparent conductive layer and an opaque conductive layer disposed on the transparent conductive layer.

3. The organic light emitting display device according to claim 2, wherein:

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer and the opaque conductive layer, which are stacked at the remaining region except for the second light emitting region in the pixel circuit, and

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer at the first and second light emitting regions.

4. The organic light emitting display device according to claim 2, wherein:

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer and the opaque conductive layer, which are stacked at a region overlapping the active layer, and

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer at a region non-overlapping the active layer.

5. The organic light emitting display device according to claim 1, wherein the anode electrode overlaps the switching transistor and the driving transistor, and the color filter is interposed between the anode electrode and the switching and driving transistors.

6. The organic light emitting display device according to claim 1, wherein:

the bank exposes the anode electrode of the light emitting device, which is disposed at the first and second light emitting regions, and

the organic layer and the cathode electrode of the light emitting device are stacked on the anode electrode of the first and second light emitting regions exposed by the bank.

7. The organic light emitting display device according to claim 1, wherein electrodes disposed at regions corresponding to contact holes disposed at the pixel circuit include the transparent conductive layers.

8. The organic light emitting display device according to claim 2, wherein the pixel circuit further comprises a storage capacitor disposed at the first light emitting region, and

wherein the storage capacitor includes a storage lower electrode connected to the switching thin film transistor and the storage upper electrode connected to the driving thin film transistor.

9. The organic light emitting display device according to claim 8, wherein the storage lower electrode and the storage upper electrode are composed of the transparent conductive layer.

10. The organic light emitting display device according to claim 8, wherein the drain electrode of the driving transistor is connected to the storage upper electrode exposed by a storage contact hole, and

wherein the drain electrode of the driving transistor and the storage upper electrode disposed at regions corresponding to the storage contact holes include the transparent conductive layers.

11. A method of fabricating an organic light emitting display device having a plurality of sub-pixels comprising:

forming a pixel circuit at each sub-pixel region of a substrate;

forming a color filter on the substrate where the pixel circuit is formed;

forming an anode electrode of a light emitting device connected to the pixel circuit;

forming a bank to define a first emitting light area where the pixel circuit is not disposed and a second emitting light area where the pixel circuit is disposed; and

forming an organic light emitting layer and a cathode electrode of the light emitting device in the first and second light emitting regions,

wherein at least one of electrodes in the pixel circuit includes a transparent conductive layer in the second light emitting region.

12. The method according to claim 11, wherein:

forming the pixel circuit comprises forming a first source electrode and a first drain electrode of a switching thin film transistor and a second source electrode and a second drain electrode of a driving thin film transistor, on the substrate,

forming the first source electrode, the first drain electrode, the second source electrode and the second drain electrode comprises;

sequentially forming the transparent conductive layer and an opaque conductive layer on the substrate;

forming a photoresist pattern having a multi-step structure on the opaque conductive layer;

etching the opaque layer and the transparent layer using the photoresist pattern;

ashing the photoresist pattern; and

etching the opaque conductive layer disposed at the second light emitting region using the ashed photoresist pattern.

13. The method according to claim 12, wherein:

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer and the opaque conductive layer, which are stacked at the remaining region except for the second light emitting region in the pixel circuit, and

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer at the first and second light emitting regions.

14. The method according to claim 12, wherein:

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer and the opaque conductive layer, which are stacked at a region overlapping the active layer, and

each of the source electrode and the drain electrode of each of the driving transistor and the switching transistor is disposed to include the transparent conductive layer at a region non-overlapping the active layer.