KR100749490B1 - Organic light emitting diode display device and method for fabricating thereof - Google Patents

Abstract

An organic light emitting diode display device and a method for fabricating the same are provided to reduce manufacturing cost through the reduction of masks by forming a pixel defined film having a spacer unit through a partial exposure process and a dry etching process using a half tone mask. An organic light emitting diode display device includes a lower structure, a first pixel electrode(22), a pixel defined film(28), an organic film(24), and a second pixel electrode(26). The lower structure is formed on a substrate. The first pixel electrode(22) is formed on the lower structure. The pixel defined film(28) has a first end which is formed on the lower structure to expose a pixel region of the first pixel electrode(22), and a second end which is formed on the first end having a narrower width than the first end. The organic film(24) is formed on the pixel region of the first pixel electrode(22). The second pixel electrode(26) is formed on the organic film(24). The first and second ends of the pixel defined film(28) are formed by a dry etching process, and a partial exposing and developing process using a half tone mask.

Description

Organic electroluminescent display and manufacturing method thereof {ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE AND METHOD FOR FABRICATING THEREOF}

1 is a cross-sectional view illustrating a schematic configuration of an organic light emitting display device according to an exemplary embodiment of the present invention.

2 is a cross-sectional view illustrating a state in which a first pixel electrode is formed on a lower structure in an organic light emitting display according to an exemplary embodiment of the present invention.

3 is a cross-sectional view illustrating a state in which a pixel defining layer forming material is coated in an organic light emitting display device according to an exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating a state in which a halftone mask is disposed on a pixel defining layer forming material in an organic light emitting display according to an exemplary embodiment of the present invention.

5 is a cross-sectional view illustrating a state in which a pixel defining layer forming material is partially exposed and developed in an organic light emitting display according to an exemplary embodiment of the present invention.

6 is a cross-sectional view illustrating a dry etching process in an organic light emitting display device according to an exemplary embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display and a method of manufacturing the same, and more particularly, to an organic light emitting display and a method of manufacturing the same, which can reduce the number of masks.

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 Display (LCD), Field Emission Display (FED), Plasma Display Panel (PDP) and Organic Light Emitting Diode Display (Organic Light Emitting Diode Display). Device).

The organic light emitting display device is a self-luminous display device that electrically excites an organic compound to emit light. The organic light emitting display device may display an image by voltage driving or current driving N × M organic light emitting devices.

The organic light emitting diode has a diode characteristic and is also called an organic light emitting diode (OLED). The organic light emitting diode includes an anode electrode as a hole injection electrode, an organic layer as a light emitting layer, and a cathode electrode as an electron injection electrode.

The organic light emitting device having such a configuration emits light when holes and electrons are injected into the organic film from the anode electrode and the cathode electrode, respectively, when the exciton in which the injected holes and electrons are combined falls from the excited state to the ground state. .

In general, the organic light emitting display device including the organic light emitting diode may be classified into an active matrix method and a passive matrix method according to a driving method.

Among these, the organic light emitting display device driven by the active matrix method includes a driving circuit board. A driving circuit portion including a plurality of thin film transistors and a storage capacitor is formed on the driving circuit substrate, and the driving circuit portion is protected by the planarization film.

An organic light emitting device is formed on the planarization film. As described above, the organic light emitting diode includes a first pixel electrode and a second pixel electrode, and an organic film disposed between the electrodes.

Here, a lower first pixel electrode is typically used as an anode electrode, an upper second pixel electrode is used as a cathode electrode, and a lower first pixel electrode is electrically connected to a thin film transistor of a driving circuit unit.

The organic light emitting element having the above-described configuration is separated from the adjacent element by the pixel defining layer formed between each element.

Meanwhile, in the organic electroluminescent display of the above-described structure, spacers for improving impact resistance have been formed on the pixel defining layer.

Therefore, when forming the pixel defining layer and the spacer, the pixel defining layer is formed by coating the pixel defining layer and then performing a photo process using a mask, and then coating the spacer forming material and then applying the mask. The used photo process is performed to form a spacer.

As described above, since the pixel defining layer and the spacer are respectively formed by using the two photolithography processes, there is a problem that the manufacturing cost increases due to the increase in the number of masks.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a method of manufacturing an organic light emitting display device capable of reducing the number of masks.

Another object of the present invention is to provide an organic light emitting display device including a pixel defining layer in which a spacer part is integrally formed.

The technical problem mentioned above,

A pixel defining layer formed on the lower structure on the substrate to expose the pixel region of the first pixel electrode is achieved by an organic electroluminescent display device consisting of two stages of different widths formed by a partial exposure and development process and a dry etching process. Can be.

According to the embodiment of this structure, since the upper two ends can be used as a spacer, the number of masks for forming a spacer can be reduced.

In example embodiments, the lower structure may include a driving circuit unit and a planarization layer covering the circuit unit, and a first pixel electrode and a pixel defining layer may be formed on the planarization layer.

The organic layer may include a common layer commonly used regardless of the color of the pixel, and a light emitting layer formed of different materials according to the color of the pixel, wherein the common layer includes the first pixel electrode and the pixel defining layer. It can form on a phase.

The first pixel electrode may be used as an anode electrode, and the second pixel electrode may be used as a cathode electrode.

The organic light emitting display having the above-described structure includes forming a lower structure on a substrate, forming a first pixel electrode, a first end formed on the lower structure, and a smaller width than the first end. And forming a pixel defining layer exposing a pixel region of the first pixel electrode, forming an organic layer, and forming a second pixel electrode. Can be.

The pixel defining layer may include coating a pixel defining layer forming material, disposing a halftone mask on the substrate, performing a partial exposure and development process using the halftone mask, and a dry etching process. It may be prepared according to the steps to be performed.

The lower structure may be formed by forming a buffer film on a substrate, forming a thin film transistor on the buffer film, and forming a planarization film covering the thin film transistor.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In describing the following embodiments, when a portion such as a layer, a film, etc. is formed "on" of another portion, it is not only when it is "just above" the other portion but also when there is another portion in the middle. Include.

1 is a cross-sectional view illustrating a schematic configuration of an organic light emitting display device according to an exemplary embodiment of the present invention.

2 to 6 are cross-sectional views sequentially illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention.

According to an exemplary embodiment, an organic electroluminescent display device includes a substrate 30 in which a plurality of thin film transistors 10 and organic light emitting elements 20 are provided in a display area, and a sealant to seal the display area. It includes an encap glass (not shown) sealed to the substrate 30.

Here, the substrate 30 may be a glass substrate of a transparent material, a resin material of a opaque material or a metal substrate.

A buffer layer 32 is provided on the substrate 30, a thin film transistor 10 is provided in a portion of the buffer layer 32, and an organic light emitting device 20 is disposed on the thin film transistor 10. do.

Hereinafter, configurations of the thin film transistor 10 and the organic light emitting diode 20 will be described in more detail.

The semiconductor layer 10a is provided on the buffer film 32, and the gate insulating film 10b is provided on the semiconductor layer 10a and the buffer film 32.

A gate electrode 10c is provided on the gate insulating film 10b, an interlayer insulating film 10d is provided on the gate electrode 10c and the gate insulating film 10b, and a source / drain electrode 10e is provided on the interlayer insulating film 10d. Is provided. In this case, the source / drain electrode 10e is electrically connected to the semiconductor layer 10a through a connection hole of the interlayer insulating layer 10d.

The planarization film 10f is provided on the source / drain electrode 10e and the interlayer insulating film 10d, and the first pixel electrode 22 is provided on the planarization film 10f, and the first pixel electrode 22 is provided. Is electrically connected to the source / drain electrode 10e through a connection hole of the planarization film 10f.

The first pixel electrode 22 may be used as an anode electrode, and in the case of a bottom emission method, the first pixel electrode 22 may be made of a transparent or translucent conductive film such as indium tin oxide (ITO) or indium zinc oxide (IZO). In the case of the top emission method, a metal film may be further included in addition to the transparent or translucent conductive film.

The pixel portion of the first pixel electrode 22 is exposed by a pixel defining layer 28 formed on the planarization layer 10f, and the exposed first pixel electrode 22 and the pixel defining layer 28 are exposed. ), The organic layer 24 and the second pixel electrode 26 are sequentially stacked.

The second pixel electrode 26 may be used as a cathode electrode.

In addition, the organic layer 24 is configured to display any one of red (R), green (G), and blue (B), and a common layer that can be commonly used regardless of the color, and It may include a light emitting layer formed separately according to the color.

A hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer (EIL) may be used as the common layer.

In FIG. 1, the organic layer 24 is formed on the entire surface of the organic layer 24 in the same manner as the second pixel electrode 26. However, only the common layer of the organic layer 24 is formed on the entire surface. It is formed independently.

In the organic light emitting display device having such a configuration, the pixel defining layer 28 is formed in a two-stage shape including a lower one end 28a and an upper two end 28b.

The first end 28a and the second end 28b may have different widths. For example, the second end 28b may have a smaller width than the first end 28a.

The second end 28b serves as a spacer for improving the impact resistance of the organic light emitting device.

Hereinafter, a method of manufacturing the organic light emitting display device having the above configuration will be described.

First, a lower structure is formed on the substrate 30. Although the lower structure may be displayed in various forms according to the driving method and the light emitting method of the device, since the active light emitting display of the top emission type is described as an example in the embodiment of the present invention, The lower structure includes a planarization film 10f and components provided under the film 10f, such as the thin film transistor 10.

After the lower structure is formed, the first pixel electrode 22 is formed on the planarization film 10f by using an electrode forming material (indium-tin-oxide) in the deposition chamber, and the pixel defining layer 28 is formed. The entire pixel defining layer forming material 28 ′ is formed to be coated.

Subsequently, as shown in FIG. 4, a half tone mask 40 is disposed above the substrate 30.

The halftone mask may include a blocking region that blocks light of a light source (not shown) and a transmission region that transmits the light.

After the halftone mask 40 is disposed above the substrate 30, partial exposure and development processes are performed using light generated from a light source (not shown).

FIG. 5 illustrates a state after performing the partial exposure and development process, wherein the pixel defining layer forming material 28 ′ remains a part of thickness after the partial exposure and development process, and includes two end portions 28b. The pixel defining layer 28 is formed first.

Subsequently, a dry etching process is performed to selectively remove a portion of the pixel defining layer forming material 28 ′ remaining therein. As illustrated in FIG. 6, the pixel definition including the first and second ends 28a and 28b is illustrated. The film 28 can be formed.

After the pixel defining layer 28 is formed, the organic layer 24 and the second pixel electrode 26 are sequentially stacked.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

As described above, in the method of manufacturing the organic light emitting display device according to the exemplary embodiment of the present invention, the pixel defining layer having the spacer part (two ends) may be formed by a partial exposure process using a halftone mask and a dry etching process. In addition, the number of masks can be reduced, thereby reducing manufacturing costs.

Claims (6)

A lower structure formed on the substrate; A first pixel electrode formed on the lower structure; A pixel defining layer having a first end formed on the lower structure to expose the pixel region of the first pixel electrode and a second end formed on the first end with a smaller width than the first end; An organic layer formed in the pixel region of the first pixel electrode; And A second pixel electrode formed on the organic layer Including; And the first and second ends of the pixel defining layer are formed by a partial exposure and development process using a halftone mask and a dry etching process. The method of claim 1, And the lower structure includes a driving circuit portion and a planarization layer covering the circuit portion. The method of claim 2, The first pixel electrode and the pixel defining layer are formed on the planarization layer. The method according to any one of claims 1 to 3, The first pixel electrode is used as an anode electrode, and the second pixel electrode is used as a cathode electrode. Forming a substructure on the substrate; Forming a first pixel electrode; Forming a pixel defining layer having a first end formed on the lower structure and a second end formed on the first end with a smaller width than the first end, and exposing a pixel region of the first pixel electrode; Forming an organic film; And Forming a second pixel electrode Including; Forming the pixel defining layer may include Coating a pixel defining layer forming material; Disposing a halftone mask on the substrate; Performing a partial exposure and development process using the halftone mask; And Steps to perform a dry etching process Method of manufacturing an organic electroluminescent display comprising a. The method of claim 5, Forming a lower structure on the substrate, Forming a buffer film on the substrate; Forming a thin film transistor on the buffer film; And Forming a planarization film covering the thin film transistor Method of manufacturing an organic electroluminescent display comprising a.

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