Organic light emitting display device comprising auxiliary electrode having void therein and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9806279-B2
Application number	US-201514792660-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Jul 8, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

Provided are an organic light emitting display device and a manufacturing method thereof. In the organic light emitting display device, after an auxiliary electrode having a multilayer structure including different kinds of metals different in etching speed is formed, a void is formed within the auxiliary electrode upon formation of an anode. The resulting structure is created by a simplified process, with contact reliability between a cathode and the auxiliary electrode being enhanced, while resistance of the cathode is reduced.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a first electrode disposed in each of a plurality of subpixels of a substrate;
a driving thin film transistor (TFT) and a connection electrode disposed below the first electrode, the connection electrode to connect the first electrode to a drain electrode of the driving TFT;
an auxiliary electrode spaced apart from the first electrode and having a void formed by at least upper, lower, and lowermost layers having different etching speeds from each other;
a bank surrounding a periphery of the first electrode and exposing a portion of the auxiliary electrode; and
a second electrode in direct contact with the auxiliary electrode at the void,
wherein the lower and lowermost layers have different etching speeds from that of the first electrode, and
wherein differences in protruding amounts among end portions of the upper, lower, and lowermost layers result in the void due to the different etching speeds.

2. The organic light emitting display device of claim 1 , wherein, in the auxiliary electrode, an etching speed of the upper layer is lower than that of the lower layer such that one end portion of the upper layer protrudes relative to a corresponding one end portion of the lower layer to form the void.

3. The organic light emitting display device of claim 2 , wherein the upper layer and the first electrode include at least one of ITO, Ag, Ag alloy, or MoTi.

4. The organic light emitting display device of claim 2 , wherein the lower layer includes Cu and the lowermost layer includes Mo or MoTi.

5. The organic light emitting display device of claim 2 , wherein at least one end portion of the lowermost layer protrudes, relative to at least the one end portion of the upper layer to form the void.

6. The organic light emitting display device of claim 5 , wherein the second electrode is in direct contact with an upper surface of the lowermost layer and the one end portion of the lower layer.

7. The organic light emitting display device of claim 1 , wherein in the auxiliary electrode, an etching speed of the upper layer is same as that of the first electrode and an etching speed of the lower and lowermost layers are the same as that of the connection electrode.

8. The organic light emitting display device of claim 7 , wherein the connection electrode is coupled with a horizontal surface of the first electrode.

9. An organic light emitting display device comprising:
a first electrode disposed in each of a plurality of subpixels of a substrate;
an auxiliary electrode spaced apart from the first electrode and including at least two layers, wherein an end portion of at least one layer below an uppermost layer of the at least two layers is receded relative to an end portion of the uppermost layer to form a void;
an organic layer on the first electrode and the upper layer;
a second electrode on the organic layer and connected to the at least one layer; and
a connection electrode formed below the first electrode and made of same materials as two lowest metal layers of the at least two metal layers, wherein the connection electrode is in direct contact with a lower surface of the first electrode.

10. The organic light emitting display device of claim 9 , wherein an etching speed of the uppermost layer is slower than that of the at least one layer below the uppermost layer of the at least two layers.

11. The organic light emitting display device of claim 10 , wherein the auxiliary electrode further includes a lowermost layer below the at least one layer, wherein an end portion of the lowermost layer protrudes from the end portion of the uppermost layer.

12. The organic light emitting display device of claim 11 , wherein an etching speed of the at least one layer is faster than an etching speed of the uppermost layer and the lowermost layer.

13. A method for manufacturing an organic light emitting display device, the method comprising:
forming a driving thin film transistor (TFT) on a substrate;
forming a connection electrode and an auxiliary electrode pattern including at least two different metal layers on the substrate;
patterning a first electrode on the substrate with the connection electrode and the auxiliary electrode pattern formed thereon, wherein the auxiliary electrode pattern is etched to form the auxiliary electrode including the at least two different metal layers;
forming a bank surrounding a periphery of the first electrode and exposing a portion of the auxiliary electrode;
forming an organic layer on the first electrode, the auxiliary electrode, and the bank;
forming a second electrode on the organic layer,
wherein an end portion of at least one metal layer formed on a lowermost layer of the at least two metal layers is receded relative to an end portion of the uppermost layer of the at least two metal layers to form a void, and
wherein the second electrode and the auxiliary electrode are in direct contact with each other through the void.

14. The method of claim 13 , wherein the second electrode is formed to be in direct contact with an upper surface of the lowermost layer and a side surface of the at least one metal layer.

15. The method of claim 13 , wherein the patterning step that forms the auxiliary electrode pattern into the auxiliary electrode results in the auxiliary electrode having a same at least two different metal layers structure as that of the connection electrode.

Assignees

• Lg Display Co Ltd

Inventors

• Im Jonghyeok
• Kim Sejune
• Lee Joonsuk
• Lee Sojung
• Lee Jaesung

Classifications

• H10K59/873

  Encapsulations · CPC title

• H10K59/80523

  Multilayers, e.g. opaque multilayers · CPC title

• H01L51/5206

  Electricity · mapped topic

• H01L27/3279

  Electricity · mapped topic

• H01L51/56

  Electricity · mapped topic