KR100696440B1 - Organic Electro-Luminescence Display Device And Fabricating Method Thereof - Google Patents

Abstract

The present invention relates to an organic light emitting display device capable of reducing line resistance and reducing power consumption, and a method of manufacturing the same.

An organic electroluminescent display device according to the present invention comprises: an anode electrode and a cathode electrode formed to cross each other with an organic light emitting layer therebetween; A first signal line supplying a first driving signal to the anode electrode; And a second signal line for supplying a second driving signal to the cathode electrode, wherein the second signal line includes a plurality of conductive layers, and the cathode electrode is the same as the cathode electrode of the plurality of conductive layers. It is characterized in that it is in direct contact with the conductive layer formed of a material.

Description

Organic electroluminescent display device and manufacturing method thereof {Organic Electro-Luminescence Display Device And Fabricating Method Thereof}

1 is a plan view schematically illustrating a conventional organic electroluminescent display device.

FIG. 2 is a diagram illustrating region A of the organic electroluminescent display device illustrated in FIG. 1 in detail.

FIG. 3 is a cross-sectional view taken along lines II ′ and II-II ′ of FIG. 2.

4 is a circuit diagram showing a line resistance appearing in a conventional multilayer signal line.

5 illustrates a portion of an organic electroluminescent display device according to an exemplary embodiment of the present invention.

6 is a circuit diagram illustrating a line resistance appearing in a signal line according to an exemplary embodiment of the present invention.

7A to 7H illustrate a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention.

    <Brief description of symbols for the main parts of the drawings>

2,102: substrate 4,104: anode electrode

12,112: cathode electrode 10,110: organic light emitting layer

6,106 insulating film 8,108 partition wall

52,152: second signal line 54: first signal line

107: support pattern

The present invention relates to an organic electroluminescent display device, and more particularly, to an organic electroluminescent display device capable of reducing line resistance and reducing power consumption, and a method of manufacturing the same.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such flat panel displays include liquid crystal displays, field emission displays, plasma display panels, and electro-luminescence (EL). Display elements).

In order to improve the display quality of such a flat panel display device and to attempt to make a large screen, there are active researches. Among these, the EL display element is a self-light emitting element that emits light by itself. The EL display element displays a video image by exciting fluorescent material using carriers such as electrons and holes.

This EL display element is roughly divided into an inorganic EL display element and an organic EL display element according to the material used.

The organic EL display element requires a high voltage of 100 to 200 V and is driven at a voltage lower than that of the inorganic EL display element by about 5 to 20 V, thereby enabling direct DC low voltage driving. In addition, the organic EL display element has excellent characteristics such as wide viewing angle, high-speed response, and high contrast ratio, so that it is used as a pixel of a graphic display, a pixel of a television image display or a surface light source. It can be used and is suitable for next-generation flat panel display because it is thin, light and good color.

FIG. 1 is a view schematically showing a general organic EL display device, FIG. 2 is a plan view specifically showing a part (area A) of FIG. 1, and FIG. 3 is a line I-I 'and II-II' of FIG. This is a cross-sectional view shown by cutting.

In the organic EL display device shown in FIGS. 1 to 3, a driving signal is formed on a display area P1 in which driving electrodes (for example, an anode electrode and a cathode electrode) are formed, and the driving electrodes of the display area P1. And a non-display area P2 where the pad portion 25 and the like for supplying the same are positioned.

In the display area P1, an anode electrode 4 and a cathode electrode 12 formed in a direction crossing the anode electrode 4 are formed.

A plurality of anode electrodes 4 are spaced apart at predetermined intervals on the substrate 2. On the substrate 2 on which the anode electrode 4 is formed, an insulating film 6 having an opening (partly exposing the anode electrode to define a light emitting area) is formed for each EL cell EL region. On the insulating film 6, a partition 8 for separating the organic light emitting layer 10 and the cathode electrode 12 to be formed thereon is positioned. The partition wall 8 is formed in a direction crossing the anode electrode 4 and has an overhang structure in which the upper end portion has a wider width than the lower end portion. On the insulating film 6 on which the partition 8 is formed, the organic light emitting layer 10 and the cathode electrode 12 made of an organic compound are sequentially deposited on the entire surface. The organic light emitting layer 10 is formed by stacking a hole injection layer 10e, a hole transport layer 10e, a light emitting layer 10c, an electron transport layer 10b, and an electron injection layer 10a on the insulating film 6.

The non-display area P2 supplies a data voltage to the anode electrode 4 through the first signal line 54 extending from the anode electrode 4 of the display area P1 and the first signal line 54. Data pads are formed, and a second signal line 52 connected to the cathode electrode 12 and a scan pad for supplying a scan voltage through the second signal line 52 are provided.

As shown in FIG. 3, the second signal line 52 includes first to fourth conductive layers 52a, 52b, 52c, and 52d, and the second to fourth conductive layers 52b, 52c, and 52d may be formed. It serves to improve the conductivity of the first conductive layer 52a. Here, the first conductive layer 52a is formed of a transparent conductive material, that is, the same material as the anode electrode, and the second and fourth conductive layers 52b, 52d are formed of molybdenum (Mo) or the like as an opaque material. The three conductive layers 52c are made of aluminum (Al) or the like.

In the conventional organic EL display device having such a structure, when a voltage is applied between the anode electrode 4 and the cathode electrode 12, electrons (or cathodes) generated from the cathode electrode 12 are electron injection layer 10a. ) And toward the light emitting layer 10c through the electron transport layer 10b. In addition, holes (or anodes) generated from the anode electrode 4 move toward the light emitting layer 10c through the hole injection layer 10d and the hole transport layer 10d. Accordingly, in the light emitting layer 10c, light is generated by collision and recombination of electrons and holes supplied from the electron transport layer 10b and the hole transport layer 10d, and the light is emitted to the outside through the anode electrode 4. The image is displayed.

Meanwhile, as shown in region B of FIG. 3, the second signal line 52 and the cathode electrode 12 come into contact with the first conductive layer 52a and the cathode electrode 12 of the second signal line 52. . In this case, the cathode electrode 12 comes into contact with the first conductive layer 52a of the second signal line 52, thereby increasing resistance to application of the scan signal.

That is, in order to transmit the scan signal from the second signal line 52 to the cathode line 12, it is necessary to pass through the second conductive layer 52b and the first conductive layer 52a, and thus, the second signal as shown in FIG. 4. The line resistance is increased by the conductive layer 52b and the first conductive layer 52a. As a result, a problem arises in that power consumption for device driving is increased.

Accordingly, an object of the present invention is to provide an organic electroluminescent display device and a method of manufacturing the same, which can reduce line resistance and reduce power consumption.

In order to achieve the above objects, the organic electroluminescent display device according to the present invention includes an anode electrode and a cathode electrode formed to cross each other with an organic light emitting layer therebetween; A first signal line supplying a first driving signal to the anode electrode; And a second signal line for supplying a second driving signal to the cathode electrode, wherein the second signal line includes a plurality of conductive layers, and the cathode electrode is the same as the cathode electrode of the plurality of conductive layers. It is characterized in that it is in direct contact with the conductive layer formed of a material.
The second signal line includes first to fourth conductive layers sequentially stacked on a substrate, and the third conductive layer is formed of the same material as the cathode electrode and longer than the fourth conductive layer. It is characterized in that the direct contact with the cathode electrode.
And partially overlap the cathode electrode and the third conductive layer.
The third conductive layer in contact with the cathode has a lower resistance than the first, second and fourth conductive layers.
The cathode electrode and the conductive layer in contact with the cathode electrode is characterized in that it comprises aluminum (Al).
A method of manufacturing an organic light emitting display device according to the present invention includes forming an anode electrode in a display area on a substrate; Forming a signal line including a plurality of conductive layers on a non-display area excluding the display area; And forming a cathode electrode intersecting the anode electrode with an organic light emitting layer interposed therebetween and in direct contact with a conductive layer formed of the same material as that of the plurality of conductive layers.
The forming of the signal line including the at least one conductive layer may include sequentially forming first to fourth conductive layers on a substrate, wherein the third conductive layer is formed of the same material as the cathode electrode. In addition, it is formed longer than the fourth conductive layer is characterized in that in direct contact with the cathode electrode.
The forming of the first to fourth conductive layers may include forming a first conductive layer on the substrate; Sequentially forming second and third conductive layers on the first conductive layer; And forming a fourth conductive layer partially exposing the third conductive layer.
The cathode may be partially overlapped with the third conductive layer.
The third conductive layer in contact with the cathode has a lower resistance than the first, second and fourth conductive layers.
The cathode electrode and the conductive layer in contact with the cathode electrode is characterized in that it comprises aluminum (Al).
Other objects and features of the present invention in addition to the above object will become apparent from the description of the accompanying examples.

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Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 7H.

5 is a cross-sectional view showing a part of an organic EL display element according to an embodiment of the present invention.

FIG. 5 is a view corresponding to the related art of FIG. 3, and is taken along line II ′ and II-II ′ of FIG. 2.

The present invention has the same structure except that the cathode line 112 and the second signal line 152 are in contact with the conductive layer formed of the same material.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1, 2, and 5.

In the display area P1 of the present invention, an anode electrode 104 and a cathode electrode 112 formed in a direction intersecting the anode electrode 104 are formed.

A plurality of anode electrodes 104 are formed on the substrate 102 spaced apart from each other at predetermined intervals. On the substrate 102 on which the anode electrode 104 is formed, an insulating film 106 having an opening (partly exposing the anode electrode to define a light emitting region) for each EL cell EL region is formed. On the insulating layer 106, a partition wall 108 for separating the organic light emitting layer 110 and the cathode electrode 112 to be formed thereon is positioned. The partition 108 is formed in a direction crossing the anode electrode 104 and has an overhang structure in which the upper end portion has a wider width than the lower end portion. On the insulating layer 106 on which the partition 108 is formed, the organic light emitting layer 110 and the cathode electrode 112 made of an organic compound are sequentially deposited on the entire surface. The organic light emitting layer 110 is formed by stacking a hole injection layer 110e, a hole transport layer 110e, a light emitting layer 110c, an electron transport layer 110b, and an electron injection layer 110a on the insulating layer 106.

In the non-display area P2, a first signal line 154 extended from the anode electrode 104 of the display area P1 and a data voltage supplied to the anode electrode 104 through the first signal line 154. Data pads are formed, and a second signal line 152 connected to the cathode electrode 112 and a scan pad for supplying a scan voltage through the second signal line 152 are provided.

The second signal line 152 includes first to fourth conductive layers 152a, 152b, 152c and 152d, and the second to fourth conductive layers 152b, 152c and 152d include the first conductive layer 152a. It serves to improve the conductivity. Here, the first conductive layer 152a is formed of a transparent conductive material, the second and fourth conductive layers 152b and 152d are formed of molybdenum (Mo) as an opaque material, and the third conductive layer 152c is formed of a transparent conductive material. It is formed of aluminum (Al) or the like.

Here, the third conductive layer 152c has a smaller resistance than the first, second and fourth conductive layers 152a, 152b and 152d, and the first, second and fourth conductive layers 152a, 152b and 152d. Are formed to extend in the direction of the cathode line 112 rather than. In this case, the cathode electrode 112 is in contact with the side surface of the third conductive layer 152c or partially overlapped as shown in FIG. 5. Accordingly, the third conductive layer 152c of the second signal line 152 and the cathode line 112 may be in direct contact, thereby reducing line resistance and thus reducing power consumption.

Referring to FIG. 6, the third conductive layer 152c and the cathode electrode 112 of the second signal line 152 include aluminum (Al) having low resistivity. By directly contacting the materials having low resistivity, there is no resistance between the cathode line 112 and the third conductive layer 152c as shown in FIG. 6. As a result, the line resistance is significantly reduced, which saves power consumption for device operation.

As such, the organic electroluminescent display device according to the present invention has the lowest resistance in the second signal line 152 and extends the third conductive layer 152c formed of the same material as the cathode electrode 112 than the other conductive layers. Is formed. Accordingly, the cathode electrode 112 and the third conductive layer 152c are in direct contact with each other, thereby reducing line resistance. As a result, power consumption for driving the device is reduced.

7A to 7H are views for explaining a method of manufacturing an organic EL display device according to the present invention.

First, a transparent conductive material is deposited on a substrate 102 formed using soda lime or hardened glass, and then patterned by a photolithography process and an etching process to display the display region P1 as shown in FIG. 7A. An anode electrode 104 is formed on the first conductive layer 152a and a first signal line not shown in the drawing in the non-display area P2. Here, the first conductive layer 152a is included in the second signal line 152, and indium tin oxide or SnO 2 is used as the transparent conductive material.

An opaque conductive material, such as molybdenum (Mo), is deposited on the substrate 102 on which the anode electrode 104 and the first conductive layer 152a are formed, and then patterned by a photolithography process and an etching process. As shown in FIG. 2, a second conductive layer 152b overlapping with the first conductive layer 152a is formed.

Aluminum (Al) is entirely deposited on the non-display area P2 on which the second conductive layer 152b is formed, and then patterned by photolithography and etching, thereby as shown in FIG. 7C. A third conductive layer 152c is formed which extends from the conductive layer 152a and contacts the substrate 102 step by step.

Meanwhile, the second and third conductive layers 152b and 152c may be simultaneously formed by one patterning process by continuous deposition. In this case, the second and third conductive layers 152b and 152c are formed to extend than the first conductive layer 152a.

An opaque conductive material, for example, molybdenum (Mo), is deposited on the non-display area P2 on which the third conductive layer 152c is formed, and then patterned by a photolithography process and an etching process. As a result, as shown in FIG. 7D, the fourth conductive layer 152d is formed. Here, the fourth conductive layer 152d has the same line width and length as the first conductive layer 152a and is formed to overlap. Accordingly, the end of the third conductive layer 152b is exposed to the outside.

The photosensitive insulating material is coated on the substrate 102 on which the second signal line 152 is formed by spin-coating, and then patterned by a photolithography process to display the display area as shown in FIG. 7E. An insulating film 106 exposing the light emitting region of P1 is formed.

After the photosensitive organic material is deposited on the insulating layer 106 and patterned by a photolithography process and an etching process, the partition 108 is formed in the display area P1 as shown in FIG. 7F. The partition wall 108 is formed in the non-light emitting area so as to intersect the plurality of anode electrodes 4 to distinguish the pixels.

As the deposition process is performed on the substrate 102 on which the partition 108 is formed, the organic light emitting layer 110 is formed as shown in FIG. 7G.

As a metal material is deposited on the substrate 102 on which the organic light emitting layer 110 is formed, the third conductive layer 152c of the second signal line 152 is formed in parallel with the partition wall 108 as shown in FIG. 7H. A cathode electrode 112 is formed in direct contact with the cathode. Here, the cathode electrode 112 is formed to partially overlap the third conductive layer 152c.

As described above, the organic EL display device and the method of manufacturing the same according to the present invention have the lowest resistance in the second signal line, and the third conductive layer formed of the same material as the cathode electrode is formed to extend than other conductive layers. Accordingly, the cathode and the third conductive layer are in direct contact with each other, thereby reducing the line resistance. As a result, power consumption for driving the device is reduced.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (11)

An anode electrode and a cathode electrode formed to cross each other with the organic light emitting layer therebetween; A first signal line supplying a first driving signal to the anode electrode; A second signal line for supplying a second driving signal to the cathode; The second signal line is composed of a plurality of conductive layers, And the cathode electrode is in direct contact with a conductive layer formed of the same material as the cathode electrode among the plurality of conductive layers. The method of claim 1, The second signal line is It consists of the first to fourth conductive layers sequentially stacked on the substrate, And the third conductive layer is made of the same material as the cathode and is formed longer than the fourth conductive layer so as to be in direct contact with the cathode. The method of claim 2, And an organic light emitting display device partially overlapping the cathode electrode and the third conductive layer. The method of claim 2, And the third conductive layer in contact with the cathode has a lower resistance than the first, second and fourth conductive layers. The method of claim 1, The cathode and the conductive layer in contact with the cathode comprises an aluminum (Al). Forming an anode electrode in a display area on the substrate; Forming a signal line including a plurality of conductive layers on a non-display area excluding the display area; Forming a cathode electrode intersecting the anode electrode with an organic light emitting layer interposed therebetween and directly contacting a conductive layer formed of the same material as the one of the plurality of conductive layers. Manufacturing method. The method of claim 6, Forming a signal line consisting of the at least one conductive layer Sequentially forming the first to fourth conductive layers on the substrate, And the third conductive layer is formed of the same material as the cathode and is formed longer than the fourth conductive layer to be in direct contact with the cathode. The method of claim 7, wherein Forming the first to fourth conductive layers Forming a first conductive layer on the substrate; Sequentially forming second and third conductive layers on the first conductive layer; Forming a fourth conductive layer partially exposing the third conductive layer. The method according to any one of claims 7 and 8, And the cathode electrode partially overlaps the third conductive layer. The method of claim 7, wherein The third conductive layer in contact with the cathode electrode has a lower resistance than the first, second, and fourth conductive layer. The method of claim 6, The cathode and the conductive layer in contact with the cathode comprises a aluminum (Al) manufacturing method of an organic light emitting display device.

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