KR102617886B1 - Organic light emitting display - Google Patents

Abstract

An organic light emitting display device capable of minimizing outgassing generated from a flat layer according to an embodiment of the present invention is provided. A first electrode, a flattening layer, a buffer layer, and a second electrode are disposed on the substrate. The first electrode and the second electrode are electrically connected through a first contact hole in the flat layer and a second contact hole in the buffer layer, and the aperture of the first contact hole is arranged to be larger than the aperture of the second contact hole. The buffer layer covers the planar layer opened by the first contact hole to minimize outgassing from the planar layer, thereby providing an organic light emitting display device with improved lifespan reliability and high manufacturing stability.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY}

The present invention relates to an organic light emitting display device, and more specifically, to providing an organic light emitting display device with improved reliability by minimizing damage to electrodes caused by gases generated from an organic material layer.

Organic light emitting display devices are self-emitting display devices, and unlike liquid crystal displays, they do not require a separate light source and can be manufactured in a lightweight and thin form. In addition, organic light emitting display devices are not only advantageous in terms of power consumption due to low voltage driving, but also have excellent color rendering, response speed, viewing angle, and contrast ratio (CR), and are being studied as next-generation displays.

An organic light emitting display device includes an organic light emitting layer made of organic material. Excitons are formed during the excitation process when electrons and holes injected through two electrodes meet and recombine in the organic light-emitting layer, and the energy generated from the excitons causes the organic light-emitting layer to emit light.

Electrons and holes are injected through an anode, which is a pixel electrode, and a cathode, a common electrode, and a driving element is placed to control the current injected into the pixel electrode.

In order to more smoothly inject electrons and holes, the organic light-emitting layer may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer.

An organic light emitting display device displays information on a screen by emitting a plurality of pixels on which an organic light emitting layer is arranged. Depending on the method of driving the pixels, it is either an active matrix type organic light emitting diode display (AMOLED) or a passive display. It is classified into a passive matrix type Organic Light Emitting Diode display (PMOLED).

AMOLED displays images by controlling the current flowing through an Organic Light Emitting Diode (OLED) using a thin film transistor (TFT).

AMOLED includes a switching TFT, a driving TFT connected to the switching TFT, and an organic light emitting diode connected to the driving TFT.

The switching TFT is formed where the scan line and data line intersect. The switching TFT functions to select pixels. The switching TFT includes a gate electrode, a semiconductor layer, a source electrode, and a drain electrode that branch from the scan line. And the driving TFT serves to drive the organic light emitting diode of the pixel selected by the switching TFT. The driving TFT includes a gate electrode connected to the drain electrode of the switching TFT, a semiconductor layer, and a source electrode and drain electrode connected to a driving current wiring. The drain electrode of the driving TFT is connected to the anode electrode of the organic light emitting diode.

A flat layer exists on the source electrode, drain electrode, and semiconductor layer that constitutes the TFT, and on a large number of electrode wires connected thereto. The planarization layer may be composed of one layer or multiple layers. A multi-layer planarization layer may be used to efficiently arrange complex electrodes in a high-resolution and high-performance organic light emitting display device with a complex pixel structure.

The flat layer can be formed by coating an organic material such as polyimide, benzocyclobutene series resin, or acrylate in liquid form and then curing it. However, over time, gas may be generated from organic materials, etc., and the generated gas affects the electrical connection relationship between the anode electrode or cathode electrode and the organic light-emitting layer and interferes with the flow of current. Accordingly, the effective light emission area of the pixel can be reduced.

The gas generated inside such an organic light emitting display device is called out-gasing, and the out gas can affect the process stability of manufacturing the organic light emitting display device and the reliability of the product lifespan.

Organic light emitting diode display device and manufacturing method thereof (Patent Application No. 10-2011-0094832)

In order to implement organic light emitting display devices with high resolution and high performance at the same time, organic light emitting display devices require high integration of TFTs and electrodes.

For efficient design of electrodes and TFTs for various purposes, organic light emitting display devices need to be designed with a multi-layer electrode structure.

An organic light emitting display device in which multilayer electrodes are arranged in this way can use a multilayer planarization layer to planarize the pixel electrode in contact with the organic light emitting layer.

The planarization layer may be disposed in the display area and non-display area of the organic light emitting display device, and the planarization layer may generate hydrogen, oxygen, or moisture over time or during the manufacturing process. Moreover, a plurality of electrodes disposed in the organic light emitting display device may have a connection structure with each other, and in this case, electrodes at different positions may be connected using contact holes that open the planarization layer.

When placing contact holes and electrodes on a flat layer, there was a problem in that the electrodes placed on the top of the flat layer were abnormally placed due to outgassing generated from the flat layer.

In addition, the organic light-emitting layer may be oxidized by outgassing that may be generated in the flat layer over time or during the manufacturing process, and the electrodes that must be placed in a vacuum during the manufacturing process may be oxidized. There was a problem that the irregular arrangement could cause manufacturing defects and lower the lifespan reliability of the manufactured organic light emitting display device. Accordingly, the inventors of the present invention have invented a new structure for an organic light emitting display device that can improve the manufacturing process stability in manufacturing an organic light emitting display device by minimizing the gas generated in the flat layer and increase the lifespan reliability of the organic light emitting display device. did.

The problem to be solved according to an embodiment of the present invention is to provide an organic light emitting display device with improved process stability by minimizing outgassing due to contact holes in the planarization layer.

The problem to be solved according to an embodiment of the present invention is to provide an organic light emitting display device with improved lifetime reliability by providing a structure that can minimize outgassing generated in a connection structure between electrodes through contact holes in a flat layer.

The problems to be solved according to an embodiment of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to an embodiment of the present invention, an organic light emitting display device is provided that can enhance manufacturing stability by reducing outgassing generated from a flat layer. The organic light emitting display device includes a protective layer including at least one organic material layer and a buffer layer to have a planarization function and a protective function, and a first electrode and a second electrode electrically connected through a contact hole in the protective layer. The buffer layer covers the organic material layer opened by the contact hole to minimize outgassing of specific gases from the organic material layer to the outside and is configured to minimize the exposed area of the organic material layer. As the protective layer covers the inside of the contact hole to minimize exposure of the organic layer, outgassing that may occur in the organic layer can be minimized.

An organic light emitting display device with improved lifetime reliability is provided according to an embodiment of the present invention. The organic light emitting display device includes a first electrode on a substrate, a planarization layer on the first electrode, a buffer layer on the planarization layer, and a second electrode on the buffer layer. The first electrode and the second electrode are electrically connected through a first contact hole in the flat layer and a second contact hole in the buffer layer, and the diameter of the first contact hole is larger than that of the second contact hole. The buffer layer covers the flat layer open due to the contact hole, and outgassing from the flat layer can be minimized.

The present invention has the effect of minimizing outgassing from the organic material layer and improving the manufacturing stability of the organic light emitting display device by covering the inside of the contact hole of the organic material layer with a buffer layer to minimize exposure of the organic material layer.

Additionally, the lifespan and reliability of the organic light emitting display device can be improved by using a protective layer configured to minimize the generation of outgassing.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Since the content of the invention described above in the problem to be solved, the means for solving the problem, and the effect do not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content of the invention.

1 is a schematic plan view for explaining an organic light emitting display device according to an embodiment of the present invention.
FIG. 2 is a schematic plan view illustrating a connection structure between electrodes through contact holes in an organic light emitting display device according to an embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view taken along line A-A' of FIG. 2 to illustrate a stacking relationship for the arrangement and connection structure of electrodes in an organic light emitting display device according to an embodiment of the present invention.
FIG. 4 is a schematic enlarged view of area

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be combined or combined with each other, partially or entirely, and various technological interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

1 is a schematic plan view for explaining an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 1 , the organic light emitting display device 100 has an active area where pixels are arranged in a matrix to display an image, a dummy area where dummy pixels are formed, an ESD area, and a link. Includes area. Except for the active area, the dummy area, ESD area, and link area are formed in the bezel area.

A plurality of electrostatic discharge circuits are formed in the ESD area. The electrostatic discharge circuit may be composed of a thin film transistor (TFT), and protects the TFT array in the active area by discharging overcurrent due to static electricity generated in the link area to an external ground (GND).

A plurality of driving elements are disposed in the active area. Each of the plurality of driving elements includes at least one thin film transistor including a source electrode, a drain electrode, a semiconductor layer, and a gate electrode. The gate electrode, source electrode, and drain electrode of the thin film transistor disposed in the active region have a multilayer structure in which multiple metal layers are stacked. For example, the gate electrode may be made of a multi-layer structure containing molybdenum (Mo) and titanium (Ti), and the source electrode and drain electrode may be stacked in order of titanium (Ti), aluminum (Al), and titanium (Ti). It can be made up of a Ti/Al/Ti structure.

A plurality of VDD electrodes 30 for supplying a driving voltage (VDD) to a plurality of pixels and a first electrode 20 for supplying a data voltage (Vdata) to a plurality of pixels are formed in the link area and the ESD area. there is.

Although not shown in the drawing, VDD is supplied to four pixels based on a horizontal line through one VDD electrode 30. Pixels are formed in a left-right symmetrical structure with respect to the VDD electrode 30, and two first electrodes 20 are formed between the two pixels.

As in the active area, ESD circuits are formed in a left-right symmetrical structure with respect to the VDD electrode 30 in the ESD area, and two first electrodes 20 are formed between the two ESD circuits.

The structure of the ESD circuit is such that, when an overcurrent occurs while the driving voltage is supplied from the COF bonding area formed on the outside of the panel to the active area through the VDD electrode 30, the overcurrent is distributed and discharged through the ESD circuit. Here, the overcurrent is transmitted to the adjacent ESD circuit through the second electrode 40 and discharged to the outside through the first electrode 20.

Likewise, in the ESD area in the bezel area, the first electrode 20 and the second electrode 40 need to be connected across the VDD electrode 30. For this purpose, although not shown in FIG. 1, it is necessary to provide a multi-layer protective layer or a multi-layer flattening layer and a contact hole for connection between electrodes.

Also, although not explained in detail, each pixel in the active area requires a compensation circuit for internal compensation in addition to the switching TFT in order to implement a high-performance pixel. In the compensation circuit, a number of TFTs, such as TFTs for compensation and TFTs for sensing and controlling the threshold voltage, are placed. For this, as in the bezel area, multi-layer flattening layers, insulating layers, and protective layers are required to place electrodes. , various contact holes are needed for the connection structure between electrodes.

FIG. 2 is a schematic plan view illustrating a connection structure between electrodes through contact holes in an organic light emitting display device according to an embodiment of the present invention.

As explained in FIG. 1, the organic light emitting display device includes arrangement of electrodes for driving pixels in the active area, connection between electrodes using contact holes, and connection between electrodes of the ESD circuit in the bezel portion. In this specification, the ESD circuit in the bezel portion shown in FIG. 2 is described as an example among various connections between electrodes, and the connection structure between electrodes that reduces outgassing is explained.

A plurality of electrostatic discharge circuits (ESD) are formed in the ESD area. The electrostatic discharge circuit (ESD) may be composed of a thin film transistor and protects the TFT array in the active area by discharging overcurrent due to static electricity generated in the link area to the external ground (GND).

The link area and the ESD area include a plurality of VDD electrodes 130 for supplying a driving voltage (VDD) to a plurality of pixels and a plurality of first electrodes 120 for supplying a data voltage (Vdata) to a plurality of pixels. It is formed.

A driving voltage (VDD) is supplied to four pixels based on a horizontal line through one VDD line 130. Pixels are formed in a left-right symmetrical structure with respect to the VDD line 130, and two first electrodes 120 are formed between the two pixels.

As in the active area, ESD circuits (ESD) are formed in a left-right symmetrical structure with respect to the VDD electrode 130 in the ESD area, and two data electrodes 120 are formed between the two ESD circuits (ESD). .

The structure of this ESD circuit (ESD) disperses and discharges the overcurrent through the ESD circuit (ESD) when an overcurrent occurs when supplying a driving voltage from the COF bonding area formed on the outside of the panel to the active area through the VDD electrode 130. . Here, the overcurrent is transferred to the adjacent ESD circuit (ESD) through the second electrode 140 and discharged to the outside through the data electrode 120. Here, the VDD electrode 130 is formed in the lower gate layer, and the VDD jumping line 140 is formed in the upper gate layer.

In this way, the ESD circuit (ESD) is composed of a thin film transistor including a source electrode (S), a drain electrode (D), a gate electrode (G), and an active layer (A) on the gate electrode (G). The electrode 120 and the second electrode 140 are connected to a thin film transistor of an ESD circuit (ESD). The overcharged current in the VDD electrode 130 is discharged to the first electrode 120 through the left and right ESD circuits (ESD) of the VDD electrode 130.

At this time, the second electrode 140 passes over the first electrode 120 and is connected to the first electrode 120 constituting the ESD circuit (ESD) through the contact holes 112A and 112B.

FIG. 3 is a schematic cross-sectional view taken along line A-A' of FIG. 2 to illustrate a stacking relationship for the arrangement and connection structure of electrodes in an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 3, the connection relationship between the first electrode 120 and the second electrode 140 will be described in more detail.

A gate electrode (G) is disposed on the substrate and a gate insulating film 141 is disposed. An etch prevention layer 142 is disposed on the gate insulating film 141 and the first electrode 120 is patterned and disposed.

The first electrode 120 is made of the same material as the source electrode or drain electrode of the driving element disposed in the active region. For example, the first electrode 120 may have a Ti/Al/Ti structure in which Ti, Al, and Ti are stacked in that order. However, it is not limited to this, and the first electrode 120 may be made of the same material as the gate electrode of the driving element disposed in the active area. For example, the first electrode 120 may have a multilayer structure including Mo and Ti.

A flattening layer 143 and a buffer layer 144 are disposed on the first electrode 120, and a second electrode 140 is disposed on the buffer layer 144.

The flattening layer 143 has a flattening function of compensating for the level difference caused by the first electrode 120 on the substrate and flattening the upper surface of the substrate. The flat layer 143 may be made of a photoacrylic organic material.

The buffer layer 144 is disposed on the flattening layer 143 and has a protective function to protect the flattening layer 143 and the electrodes under the buffer layer 144. The buffer layer 144 may be made of silicon nitride (SiNx) and/or silicon oxide (SiOx), and may be made of a single-layer buffer layer or a multi-buffer layer made of the above materials.

The flattening layer 143 and the buffer layer 144 may be referred to as a protective layer that has a flattening function of flattening the upper surface of the substrate and a protective function of protecting the lower electrodes and various devices.

The planar layer 143 and the buffer layer 144 include at least one contact hole 112a and 112b exposing a portion of the first electrode 120.

The second electrode 140 may be made of the same material as the source electrode or drain electrode of the driving element disposed in the active region. For example, the second electrode 140 may have a Ti/Al/Ti structure in which Ti, Al, and Ti are stacked in that order. However, it is not limited to this, and the second electrode 140 may be made of the same material as the gate electrode of the driving element disposed in the active area. For example, the second electrode 140 may have a multilayer structure including Mo and Ti.

The first electrode 120 is electrically connected to the second electrode 140 through at least one contact hole 112a and 112b. After placing the first electrode 120 according to the stacking order, the flattening layer 143 is formed. is formed through a process such as spin coating. Afterwards, the buffer layer 144 is formed. To connect the electrodes, contact holes 112a and 112b are formed using a method such as dry etching, and then the second electrode 140 is formed.

At this time, the buffer layer 144 is configured to minimize exposure of the flattening layer 143 opened by the contact holes 112a and 112b, and the second electrode 140 is It is designed to minimize abnormal placement.

FIG. 4 is a schematic enlarged view of area

Referring to FIG. 4, the flattening layer 143 does not have a direct connection with the second electrode 140.

That is, the diameter D2 of the contact hole of the flattening layer 143 is larger than the diameter D1 of the contact hole of the buffer layer 144, and the second electrode 140 is electrically connected to the first electrode 120, but the flattening layer ( 143) and the second electrode 140 are not directly connected. That is, the direct connection relationship between the flat layer 143 and the second electrode 140 is minimized.

By minimizing the connection relationship between the second electrode 140 and the flattening layer 143 in this way, the influence of the outgassing from the flattening layer 143 on the second electrode 140 can be minimized.

Specifically, the flat layer 143 may be formed by coating a photoacrylic-based organic material in liquid form and then curing it. However, over time, gas may be generated from organic materials, etc., and the generated gas affects the connection relationship between the first electrode 120 and the second electrode 140. (140) It interferes with the flow of current between them.

The gas generated inside such an organic light emitting display device is called outgas, and the outgas can affect the process stability of manufacturing the organic light emitting display device and the reliability of the product lifespan.

However, in the organic light emitting display device according to an embodiment of the present invention, the aperture D2 of the contact hole in the planarization layer 143 is larger than the aperture D1 of the contact hole in the buffer layer 144, so the buffer layer 144 is a planarization layer. It covers the open flat layer 143 due to the contact hole D2 of (143). Since the buffer layer 144 is made of an inorganic material such as silicon oxide or silicon nitride that can effectively suppress the penetration of gas, the gas generated in the flat layer 143 leaks out to the first electrode 120 and the second electrode 140. ) can be minimized affecting the connection part.

The first electrode 120 and the second electrode 140 may be made of the same material or may be made of different materials, but are not limited thereto.

For example, the first electrode 120 and the second electrode 140 may be a gate electrode, source electrode, and drain electrode constituting a TFT, and may be Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr. , Li, Ca, Mo, Ti, W, Cu, or at least one metal or alloy, and may be formed as a single layer or multiple layers.

For example, the first electrode 120 and the second electrode 140 may be multilayer electrodes made of Ti/Al/Ti or Ti/Mo/Ti.

The planarization layer 143 may be made of a photoacrylic-based material containing an organic material, and the buffer layer 144 may be a multi-layer multi-buffer layer including at least one silicon nitride layer or silicon oxide layer.

A thin film transistor and an organic light emitting display device according to embodiments of the present invention can be described as follows.

An organic light emitting display device according to an embodiment of the present invention includes a protective layer including at least one organic material layer and a buffer layer to have a planarization function and a protective function, and a first electrode and a second electrode electrically connected through a contact hole in the protective layer. Includes. The buffer layer covers the organic material layer opened by the contact hole to minimize outgassing of specific gases from the organic material layer to the outside and is configured to minimize the exposed area of the organic material layer. As the protective layer covers the inside of the contact hole to minimize exposure of the organic layer, outgassing that may occur in the organic layer can be minimized.

According to another feature of the present invention, the organic material layer may be composed of a photoacrylic-based material.

According to another embodiment of the present invention, an organic light emitting display device includes at least one driving element including a source electrode, a drain electrode, a semiconductor layer, and a gate electrode, and the source electrode and drain electrode are made of Ti/Al/Ti. It can be done.

According to another feature of the present invention, the first electrode may be made of the same material as the source electrode or the drain electrode.

According to another feature of the present invention, the second electrode may be made of the same material as the source electrode or the drain electrode.

According to another feature of the present invention, the gate electrode and the first electrode may be multilayer electrodes containing Mo and Ti.

According to another feature of the present invention, the buffer layer may be a multi-buffer layer including at least one silicon nitride layer or silicon oxide layer.

An organic light emitting display device according to an embodiment of the present invention includes a first electrode on a substrate, a planarization layer on the first electrode, a buffer layer on the planarization layer, and a second electrode on the buffer layer. The first electrode and the second electrode are electrically connected through a first contact hole in the flat layer and a second contact hole in the buffer layer, and the diameter of the first contact hole is larger than that of the second contact hole. The buffer layer covers the flat layer open due to the contact hole, and outgassing from the flat layer can be minimized.

According to another feature of the present invention, the organic light emitting display device includes an ESD circuit including a transistor for discharging constant current, and the first electrode and the second electrode may be connected to the transistor.

According to another feature of the present invention, the inner surface of the flat layer corresponding to the first contact hole may be covered by a buffer layer.

According to another feature of the present invention, the first electrode and the second electrode may be multilayer electrodes containing Al, Ti, or Mo.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: Organic light emitting display device
20, 120: first electrode
30, 130: VDD electrode
40, 140: second electrode
112a, 112b: VDD contact
141: Gate insulating film
142: Etching prevention layer
143: Flat layer
144: buffer layer

Claims (11)

An active area in which a plurality of pixels are arranged and an electrostatic discharge (ESD) area disposed outside the active area;
a plurality of driving voltage (VDD) electrodes disposed in the ESD area to supply a driving voltage to the plurality of pixels;
a plurality of electrostatic discharge circuits disposed on the left and right with respect to the driving voltage electrode and composed of transistors;
a plurality of first electrodes disposed between the plurality of electrostatic discharge circuits and electrically connected to a gate electrode of the transistor;
a protective layer including a buffer layer disposed on the plurality of first electrodes;
An organic light emitting display device comprising a second electrode disposed on the protective layer and electrically connected to the first electrode through a contact hole in the protective layer. According to claim 1,
The protective layer further includes an organic material layer disposed on the first electrode,
An organic light emitting display device, wherein the organic material layer is made of a photoacrylic-based material. According to claim 1,
disposed in the active region, further comprising at least one driving element including a source electrode, a drain electrode, a semiconductor layer, and a gate electrode, wherein the source electrode and drain electrode of the driving element are made of Ti/Al/Ti, Luminous display device. According to clause 3,
The organic light emitting display device wherein the first electrode is made of the same material as the source electrode or drain electrode of the driving element. According to clause 3,
The organic light emitting display device wherein the second electrode is made of the same material as the source electrode or drain electrode of the driving element. According to clause 3,
An organic light emitting display device, wherein the gate electrode of the driving element and the first electrode are multilayer electrodes containing Mo and Ti. According to claim 1,
The organic light emitting display device wherein the buffer layer is a multi-buffer layer including at least one silicon nitride layer or silicon oxide layer. According to claim 1,
a gate insulating film disposed on the gate electrode of the transistor to expose a portion of the gate electrode of the transistor; and
It further includes an etch prevention layer disposed to cover the gate insulating film,
A portion of the first electrode is disposed on the etch-stop layer, and the other portion is electrically connected to the exposed gate electrode of the transistor. According to clause 2,
The contact hole includes a first contact hole formed in the organic layer and a second contact hole formed in the buffer layer,
The organic light emitting display device wherein the aperture of the first contact hole is larger than the aperture of the second contact hole. According to clause 9,
An organic light emitting display device wherein an inner surface of the organic layer corresponding to the first contact hole is covered by the buffer layer. According to claim 1,
The first electrode supplies data voltage to the plurality of pixels,
When an overcurrent is generated when supplying a driving voltage to the active area through the driving voltage electrode, the overcurrent is transferred to the adjacent electrostatic discharge circuit through the second electrode and discharged to the outside through the first electrode. display device.

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