KR100692051B1 - Organic Electro Luminescence Display and Fabricating Method Thereof - Google Patents

Abstract

The present invention relates to an organic electroluminescent display device and a method of manufacturing the same, which can secure the aperture ratio of an organic electroluminescent display device while reducing the resistance of the anode electrode.

An organic electroluminescent display device according to an embodiment of the present invention includes a transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film covering the metal electrode; The entire metal electrode is covered by the insulating film.

Description

Organic electroluminescent display and manufacturing method thereof {Organic Electro Luminescence Display and Fabricating Method Thereof}             

1 is a perspective view illustrating a conventional organic electroluminescent display device.

2 is a diagram for explaining a light emission principle of an organic light emitting display device.

3 is a plan view illustrating a part of another conventional organic electroluminescent display device.

FIG. 4 is a cross-sectional view of the organic electroluminescent display shown in FIG. 3 taken along lines "I-I '" and "II-II'", respectively.

5 is a plan view illustrating a portion of an organic light emitting display device according to a first embodiment of the present invention.

FIG. 6 is a cross-sectional view of the organic electroluminescent display shown in FIG. 5 taken along the line "III-III '".

7A through 7D are steps of a method of manufacturing an organic light emitting display device according to a first embodiment of the present invention.

8 is a plan view illustrating a part of an organic light emitting display device according to a second exemplary embodiment of the present invention.

FIG. 9 is a cross-sectional view of the organic electroluminescent display shown in FIG. 8 taken along the line "IV-IV '".

10A through 10D are steps of a method of manufacturing an organic light emitting display device according to a second exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

4, 24 anode electrode 12, 32 cathode electrode

5, 25, 45: bus electrodes 6, 26: insulating film

36: first insulating film 46: second insulating film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent display device, and more particularly, to an organic electroluminescent display device capable of securing an aperture ratio of an organic electroluminescent display device while reducing resistance of an anode electrode, and a manufacturing method thereof.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such a flat panel display includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescence (“EL”). Display device).

PDP is most advantageous for large screen because of its relatively simple structure and manufacturing process, but it has the disadvantages of low luminous efficiency, low luminance and high power consumption. LCD is mainly used as a display device of notebook computers, but the demand is increasing, but it is difficult for large screens and has a large power consumption due to the backlight unit. In addition, LCDs have disadvantages of high light loss and a narrow viewing angle due to optical display devices such as polarizing filters, prism sheets, and diffusion plates. In contrast, the EL display device is roughly classified into an inorganic EL and an organic EL, and has advantages of fast response speed and high luminous efficiency, luminance, and viewing angle. In addition, the organic EL display can display an image with high luminance of tens of thousands [cd / m 2] at a voltage of about 10 [V].

1 is a perspective view showing a conventional organic EL display element, and FIG. 2 is a diagram for explaining the light emission principle of the organic EL display element.

The organic EL display element shown in Fig. 1 is formed on the substrate 2 in a direction in which the anode electrode 4 and the cathode electrode 12 cross each other.

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 (not shown) having an opening for each area of the EL cell A is formed. On the insulating layer, 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 a reverse taper structure in which the upper end portion has a wider width than the lower end portion. On the insulating film on which the partition 8 is formed, an organic light emitting material is deposited using a mask, and an organic light emitting layer 10 is formed. Subsequently, a cathode electrode 12 is formed through full deposition of the electrode material.

As shown in FIG. 2, the organic light emitting layer 10 is formed by stacking a hole injection layer 10e, a hole transport layer 10d, a light emitting layer 10c, an electron transport layer 10b, and an electron injection layer 10a. In the organic EL display device, electrons and holes are emitted when a driving signal is applied to the anode electrode 4 and the cathode electrode 12, and the electrons and holes emitted from the anode electrode 4 and the cathode electrode 12 emit light. Recombination within 10c) generates visible light. At this time, the generated visible light comes out through the anode electrode 4 to display a predetermined image or image.

In such an organic EL display element, there is a resistance by the cathode electrode 12 and the anode electrode 4. The resistive component of such an organic EL display element causes a current variation of the organic EL display element and degrades the image quality.

In particular, the anode electrode 4 is different from the cathode electrode 12 using a low resistance metal such as aluminum (Al), such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), or the like. Since it is formed of a transparent conductive material, it has a high resistance component. For this reason, as the length of the anode electrode 4 becomes longer, current deviation occurs due to voltage drop, thereby degrading image quality.

In order to solve this problem, as shown in FIG. 3, the metal bus electrode 5 is formed on the anode 4 to compensate for the high resistance component.

FIG. 3 is a plan view showing a part of another conventional organic EL display element, and FIG. 4 is a cross-sectional view of the organic EL display element shown in FIG. 3 taken along lines "I-I '" and "II-II'", respectively. to be.

3 and 4, an organic EL display element includes an EL cell formed at each intersection of an anode electrode 4 and a cathode electrode 12 formed to cross each other, and an anode electrode 4 and a cathode electrode 12 interposed therebetween. (Not shown). In addition, a barrier rib 8 is formed across the anode electrode 4 and formed parallel to the cathode electrode 12.

The anode electrode 4 is formed of a transparent conductive material such as ITO, IZO, ITZO having a good light transmittance of 90% or more, and the bus electrode 5 is disposed on the anode electrode 4 to compensate for the high resistance of the anode electrode 4. Is formed. Next, an insulating film 6 having an opening for each EL cell (not shown) region is formed on the substrate 20 on which the bus electrode 5 is formed. The partition 8 is formed on the insulating layer 6 to separate the organic light emitting layer 10 and the cathode electrode 12. The organic light emitting material is deposited on the insulating film 6 having the partition 8 formed thereon using a mask to form the organic light emitting layer 10. Subsequently, the cathode electrode 12 is formed through full deposition of the electrode material.

The bus electrode 5 used to compensate for the high resistance of the anode electrode 4 is formed of chromium (Cr), molybdenum (Mo), or aluminum (Al), a conductive material having excellent interfacial properties and low resistance. The bus electrode 5 formed on the electrode 4 is formed by overlapping the organic light emitting layer 10 and the bus line 5 by at least 1/2 of the total line width. However, since the bus electrode 5 of the organic EL display device blocks light, when the line width overlapping with the organic light emitting layer 10 becomes wider, the aperture ratio of the organic EL display device is reduced, so that the bus electrode 5 of the organic EL display device has a minimum line width. do. However, when the bus electrode 5 is formed with the minimum line width, the effect of improving the aperture ratio of the organic EL display device is increased, but it is insufficient to compensate the high resistance of the anode electrode 4 through the formation of the bus electrode 5. Will result.

Accordingly, an object of the present invention is to provide an organic EL display device and a method for manufacturing the same, which can secure the aperture ratio of an organic electroluminescent display device while reducing the resistance of the anode electrode.

An organic electroluminescent display device according to an embodiment of the present invention includes a transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film covering the metal electrode; The entire metal electrode is covered by the insulating film.

Part of the metal electrode is formed on the transparent electrode and the remaining part is formed on the substrate, characterized in that it has a stepped cross-section.

The insulating film includes a first insulating film formed on the transparent electrode and the substrate; A second insulating film covering the metal electrode and the first insulating film; The metal electrode extends from the contact portion with the transparent electrode and is formed on the first insulating film.

The width of the second insulating film is greater than the width of the first insulating film.

An organic electroluminescent layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width thereof is 1/2 or less than a width of the metal electrode.

An organic electroluminescent display device according to an embodiment of the present invention includes a transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film covering the metal electrode; The metal electrode has a stepped cross section.

An organic electroluminescent layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width thereof is 1/2 or less than a width of the metal electrode.

An organic electroluminescent display device according to an embodiment of the present invention includes a transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film having a predetermined width covering the metal electrode; An organic light emitting layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width thereof is 1/2 or less than a width of the metal electrode.

A method of manufacturing an organic light emitting display device according to an embodiment of the present invention includes forming a transparent electrode pattern on a substrate; Forming a metal electrode pattern connected to the transparent electrode; Forming an insulating film pattern on the substrate to cover the metal electrode; The insulating film may cover the entire metal electrode.

The forming of the insulating film may include forming a first insulating film pattern on the substrate over the transparent electrode and the substrate; Forming a second insulating film covering the metal electrode and the first insulating film; The metal electrode extends from the contact portion with the transparent electrode and is positioned on the first insulating film.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 10D.

FIG. 5 is a plan view showing a part of the organic EL display device according to the first embodiment of the present invention, and FIG. 6 is a cross-sectional view of the organic EL display device shown in FIG. 5 taken along the line "III-III '".

5 and 6, an organic EL display element includes an EL cell formed at each intersection of an anode electrode 24 and a cathode electrode 32 formed to cross each other, and an anode electrode 24 and a cathode electrode 32 formed thereon. (Not shown).

A plurality of anode electrodes 24 are formed on the substrate 22 at regular intervals, and are made of transparent conductive materials such as ITO, IZO, and ITZO having good light transmittance of 90% or more.

On the substrate 22 on which the anode electrode 24 is formed, a bus for compensating for the resistive component of the anode electrode 24 over the non-light emitting area B between one side of the anode electrode 24 and the anode electrodes 24. An electrode 25 is formed. Specifically, the bus electrode 25 is formed in the region where the insulating film 26 and the anode electrode 24 are to be overlapped with the entire bus electrode 25 formed on the anode electrode 24 in a subsequent process, and the organic light emitting layer The 30 and the bus electrode 25 overlap each other by 1/2 or less of the total line width of the bus electrode 25. In addition, the bus electrode 25 is formed so as to extend to be positioned in the non-light emitting area B between the anode electrodes 24. Accordingly, the bus electrode 25 is formed over one side of the anode electrode 24 and the non-light emitting region B on the substrate 22 on which the insulating film 26 is to be formed, and thus has a stepped cross section. By securing a wide line width, the resistance of the anode electrode 24 can be further reduced. The bus electrode 25 is formed of chromium (Cr), molybdenum (Mo), aluminum (Al), or the like, which is a conductive material having excellent interfacial properties and low resistance.

Then, an insulating film 26 covering the bus electrode 25 is formed on the substrate 22 on which the bus electrode 25 is formed and has an opening for each EL cell region. A partition wall 28 for separating the organic light emitting layer 30 and the cathode electrode 32 is formed on the insulating layer 26. The partition wall 28 is formed in a direction crossing the anode electrode 24, and an organic light emitting material is formed on the insulating layer 26 on which the partition wall 28 is formed by using a mask to deposit the organic light emitting layer 30. Electrode 32 is formed through full deposition of electrode material.

Therefore, by placing the bus electrode 25 formed on the anode electrode 24 in the region where the anode electrode 24 and the insulating film 26 overlap, the aperture ratio of the organic EL display element is improved, and the bus electrode ( 25 is formed with a stepped cross section in the non-light emitting area B between the anode electrode 24 and the anode electrodes 24, and the bus electrode 25 is extended by extending the bus electrode 25 to the non-light emitting area B. The line width of 25 becomes larger, thereby further reducing the resistance of the anode electrode 24.

7A to 7D are steps of a method of manufacturing an organic EL display device according to a first embodiment of the present invention.

Referring to FIG. 7A, a plurality of anode electrodes 24 are formed by depositing a transparent conductive material on the substrate 22 to a thickness of about 1500 mW and then patterning the same. At this time, the anode electrode 24 is formed to be spaced apart at a predetermined interval. The anode electrode 24 is formed of a transparent conductive material such as ITO, IZO, ITZO.

As shown in FIG. 7B, the metal material is deposited and patterned on the substrate 22 having the anode electrode 24 formed thereon, so that the non-light emitting region B between one side of the anode electrode 24 and the anode electrodes 24 is formed. The bus electrode 25 is formed over. Specifically, the bus electrode 25 is formed in the region where the insulating film 26 and the anode electrode 24 are to be overlapped with the entire bus electrode 25 formed on the anode electrode 24 in a subsequent process, and the organic light emitting layer The 30 and the bus electrode 25 overlap each other by 1/2 or less of the total line width of the bus electrode 25. In addition, the bus electrode 25 is formed over the non-light emitting region B between the anode electrodes 24 and the anode electrodes 24, and thus is formed to have a stepped cross section. The bus electrode 15 is formed of a metal material such as chromium (Cr), molybdenum (Mo), or aluminum (Al).

As the insulating material is deposited on the substrate 22 on which the anode electrode 24 and the bus electrode 25 are formed and then patterned, as shown in FIG. 7C, each of the EL cell regions on the anode electrode 24 has an opening and has a bus electrode 25. An insulating film 26 surrounding the film is formed.

A partition wall (not shown) is formed on the insulating layer 26 to separate the organic light emitting layer 30 and the cathode electrode 32. An organic compound mask is used on the substrate 22 on which the partition wall is formed as shown in FIG. 7D. As a result, the deposition organic light emitting layer 30 is formed, and subsequently, the cathode electrode 32 is formed through full deposition of the electrode material.

8 is a plan view illustrating an organic EL display device according to a second exemplary embodiment of the present invention, and FIG. 9 is a cross-sectional view of the organic EL display device illustrated in FIG. 8 taken along the line “IV-IV ′”.

8 and 9, an organic EL display element includes an EL cell formed at each intersection of an anode electrode 24 and a cathode electrode 32 formed to cross each other, and an anode electrode 24 and a cathode electrode 32 formed therein. (Not shown).

A plurality of anode electrodes 24 are formed on the substrate 22 at regular intervals, and are made of transparent conductive materials such as ITO, IZO, and ITZO having good light transmittance of 90% or more. Subsequently, a first insulating film 36 having openings is formed for each EL cell region on the anode electrode 24 on the substrate 22 on which the anode electrode 24 is formed.

On the region where the first insulating layer 36 is formed, a bus electrode 45 connected to one side of the anode electrode 24 for compensating for the high resistance component of the anode electrode 24 is formed. Specifically, the bus electrode 45 is formed in the region where the second insulating film 46 and the anode electrode 24 are to be overlapped with the entire bus electrode 45 formed on the anode electrode 24 in a subsequent process, The organic light emitting layer 40 and the bus electrode 45 are overlapped with each other by 1/2 or less of the overall line width of the bus electrode 45. In addition, the bus electrode 45 is formed such that the anode electrodes 24 are also connected to one side of the anode electrode 24 so as to extend to the region where the first insulating film 36 is formed. Accordingly, since the bus electrode 45 is insulated from the adjacent anode electrode 24 by the first insulating film 36, the bus electrode 45 can be formed to be wider by extending the bus electrode 45 on the first insulating film 36. In addition, since it is formed having a stepped cross section, a wider line width can be ensured to further reduce the resistance of the anode electrode 24.

Subsequently, a second insulating film 46 is formed on the substrate on which the bus electrode 45 is formed and has an opening for each EL cell (not shown) area and covers the bus electrode 45. The partition wall 28 for separating the organic light emitting layer 30 and the cathode electrode 32 is positioned on the second insulating layer 46. The partition wall 28 is formed in a direction crossing the anode electrode 24, and on the second insulating layer 46 on which the partition wall 28 is formed, an organic compound layer is formed using a mask to deposit the organic light emitting layer 30. The cathode electrode 32 is formed through full deposition of the electrode material.

Therefore, by positioning the bus electrode 45 formed on the bus electrode 45 in a region where the anode electrode 24 and the second insulating film 46 overlap, the aperture ratio of the organic EL display element is improved, and the bus The electrode 45 is formed to have a stepped cross section on the anode electrode 24 and the first insulating film 36, and the bus electrode 45 is insulated from the adjacent anode electrode 24 by the first insulating film 36. As a result, the bus electrode 45 can be formed wider on the first insulating film 36, thereby increasing the line width of the bus electrode 45, thereby further reducing the resistance of the anode electrode 24. Can be.

10A through 10D are steps of a method of manufacturing an organic EL display device according to a second exemplary embodiment of the present invention.

Referring to FIG. 10A, a plurality of anode electrodes 24 are formed by depositing and patterning a transparent conductive material on the substrate 22 to a thickness of about 1500 mW. At this time, the anode electrode 24 is formed to be spaced apart at a predetermined interval. The anode electrode 24 is formed of a transparent conductive material such as ITO, IZO, ITZO. Subsequently, an insulating material is deposited on the substrate 22 on which the anode electrode 24 is formed, and then patterned to form a first insulating film 36 having an opening for each EL cell region on the anode electrode 24.

As shown in FIG. 10B, a metal material is deposited and patterned on the substrate 22 on which the anode electrode 24 and the first insulating layer 36 are formed, thereby forming one side of the anode electrode 24 and the first insulating layer 36. The bus electrode 45 is formed on the region. Specifically, the bus electrode 45 is formed in a region where the entire second bus electrode 45 formed on the anode electrode 24 is to be overlapped with the second insulating film 46 and the anode electrode 24 to be formed in a subsequent process. The organic light emitting layer 30 and the bus electrode 45 are overlapped with each other by 1/2 or less of the overall line width of the bus electrode 45. In addition, the bus electrode 45 extends to a region where the first insulating layer 36 is formed while being connected to one side of the anode electrode 24. The bus electrode 25 may be formed of a metal material such as chromium (Cr), molybdenum (Mo), or aluminum (Al).

As the insulating material is deposited on the substrate 2 on which the anode electrode 4 and the bus electrode 25 are formed and then patterned, an opening is formed for each EL cell (not shown) area on the anode electrode 24 as shown in FIG. 10C. A second insulating film 46 surrounding the electrode 25 is formed.

A partition wall (not shown) is formed on the second insulating layer 26 to separate the organic light emitting layer 30 and the cathode electrode 22. As shown in FIG. 10D, an organic compound is formed on the anode electrode 24 on which the partition wall is formed. The deposition organic light emitting layer 30 is formed using a mask, and subsequently, the cathode electrode 32 is formed by depositing an electrode material on the entire surface.

As described above, the organic EL display device and the method of manufacturing the same according to the first embodiment of the present invention have the aperture ratio of the organic EL display device by forming the entire bus electrode formed on the anode electrode in the region where the anode electrode and the insulating film overlap. It will be possible to improve. In addition, the bus electrode may be formed to have a stepped cross section, and the bus electrode may be formed to extend to the non-light-emitting region to further secure a wider line width, thereby further reducing the resistance of the anode electrode. Accordingly, it is possible to prevent the deterioration of the image quality due to the current deviation by reducing the resistance of the anode electrode.

In addition, the organic EL display device and the method of manufacturing the same according to the second embodiment of the present invention are formed in the entire region of the bus electrode formed on the anode electrode in the region where the anode electrode and the second insulating film overlap, thereby reducing the aperture ratio of the organic EL display element. It can be improved. In addition, since the bus electrode has a stepped cross section and the bus electrode is insulated from the adjacent anode electrode by the first insulating film, the bus electrode is formed to extend wider on one side of the anode electrode and on the first insulating film. By securing the width, the resistance of the anode can be further reduced. Accordingly, by further reducing the resistance of the anode electrode, it is possible to prevent the image quality deterioration due to the current deviation.

It will be understood that various changes and modifications can be made by those skilled in the art through the above description 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)

A transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film covering the metal electrode; And the entire metal electrode is covered by the insulating film. The method of claim 1, And a portion of the metal electrode is formed on the transparent electrode, and the other portion is formed on the substrate to have a stepped cross section. The method of claim 1, The insulating film, A first insulating film formed on the transparent electrode and the substrate; A second insulating film covering the metal electrode and the first insulating film; And the metal electrode extends from the contact portion with the transparent electrode and is formed on the first insulating film. The method of claim 3, wherein The width of the second insulating film is greater than the width of the first insulating film organic light emitting display device. The method of claim 1, An organic electroluminescent layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width of the metal electrode and the organic light emitting layer is 1/2 or less of the width of the metal electrode. A transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film covering the metal electrode; And the metal electrode has a stepped cross section. The method of claim 6, An organic electroluminescent layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width of the metal electrode and the organic light emitting layer is 1/2 or less of the width of the metal electrode. A transparent electrode formed side by side on the substrate; A metal electrode connected to the transparent electrode; An insulating film having a predetermined width covering the metal electrode; An organic light emitting layer formed over the transparent electrode and a part of the insulating film; At least a portion of the metal electrode and the organic light emitting layer overlap each other, and an overlap width of the metal electrode and the organic light emitting layer is 1/2 or less of the width of the metal electrode. Forming a transparent electrode pattern on the substrate; Forming a metal electrode pattern connected to the transparent electrode; Forming an insulating film pattern on the substrate to cover the metal electrode; And the insulating layer covers the entire metal electrode. The method of claim 9, Forming the insulating film, Forming a first insulating film pattern on the substrate over the transparent electrode and the substrate; Forming a second insulating film covering the metal electrode and the first insulating film; And the metal electrode extends from the contact portion with the transparent electrode and is positioned on the first insulating layer. The method of claim 10, The width of the second insulating film is greater than the width of the first insulating film manufacturing method of an organic light emitting display device.

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