KR102577984B1 - Organic electroluminescence display device and method for fabricating thereof - Google Patents

Abstract

The present invention discloses an organic electroluminescent display device and a method of manufacturing the same. The organic electroluminescent display device of the present invention is a substrate in which white (W), red (R), green (G), and blue (B) sub-pixel (SP) regions are partitioned. It includes a thin film transistor disposed in each sub-pixel region of the substrate, and white (W), red (R), green (G), and blue (B) color filter layers disposed in each sub-pixel region. and an organic light emitting diode disposed in each sub-pixel area, wherein the organic light emitting diode includes a first electrode, a plurality of dot patterns disposed on the first electrode, and a plurality of dot patterns disposed on the first electrode and the dot pattern. By including an organic light-emitting layer disposed in and a second electrode disposed on the organic light-emitting layer, the light extraction efficiency of the organic light-emitting diode is improved.

Description

Organic electroluminescent display device and method of manufacturing the same

The present invention relates to an organic electroluminescent display device, and more specifically, to an organic electroluminescent display device with improved light extraction efficiency of an organic light emitting diode and a method of manufacturing the same.

Recently, various flat panel display devices that can reduce the weight and volume, which are disadvantages of cathode ray tubes, are being developed. These flat panel displays include Liquid Crystal Display (hereinafter referred to as “LCD”), Field Emission Display (FED), Plasma Display Panel (hereinafter referred to as “PDP”), and organic There is an organic electroluminescence display device, etc.

Because PDP has a simple structure and manufacturing process, it is attracting attention as the most advantageous display device for large screens despite being light and thin. However, it has the disadvantage of low luminous efficiency and brightness and high power consumption. TFT LCD (Thin Film Transistor LCD) is the most widely used flat panel display device, but has problems with a narrow viewing angle and low response speed. Organic electroluminescent displays are self-emitting devices that emit light on their own and have the advantages of fast response speed, high luminous efficiency, brightness, and viewing angle.

FIG. 1 is a diagram showing the pixel structure of a general organic light emitting display device, and FIG. 2 is a cross-sectional view taken along line I-I' of FIG. 1.

Referring to Figures 1 and 2, in a conventional organic light emitting display device, red (R), green (G), and blue (B) sub-pixel areas are defined in a matrix form, and each sub-pixel area generates white light. Organic light emitting diodes (OLED: Organic Light Emitting Diode) are placed.

As shown in the figure, a conventional organic light emitting display device is formed in a structure in which red (R), green (G), and blue (B) sub-pixels of the same width are sequentially arranged.

The organic light emitting display device corresponds to red (R), green (G), and blue (B) sub-pixel areas on an array substrate 10 on which switching transistors, driving transistors, signal wires, and storage capacitors (Cst) are formed. A red color filter layer (CR), a green color filter layer (CG), and a blue color filter layer (CB) are preferably disposed, respectively.

An overcoat layer 15 is disposed on the red (R), green (G), and blue (B) color filter layers (CR, CG, CB), and red (R), green (G) are disposed on the overcoat layer 15. ) and an organic light emitting diode (OLED) is disposed between the bank layer 60 that separates the blue (B) and blue (B) sub-pixel areas.

The organic light emitting diode (OLED) includes a red pixel electrode 20, a green pixel electrode 30, or a blue pixel electrode 40 arranged in units of red (R), green (G), and blue (B) sub-pixel areas. It consists of an organic light-emitting layer 21 and an electrode 50 arranged to correspond to each of the electrodes.

As described above, when the red (R), green (G), and blue (B) color filter layers (CR, CG, CB) are disposed on the array substrate 10, the organic light emitting layer used in the organic light emitting diode (OLED) (21) uses an organic light-emitting layer that generates white light.

As described above, when an organic light-emitting layer that generates white light is used, the red (R), green (G), and blue (B) sub-pixel areas are not distinguished, and the organic light-emitting layer 21 and the electrode ( 50) can be formed sequentially.

In particular, the electrode 50 uses a metal with high reflectivity, so that the light generated from the organic light-emitting layer 21 is red (R), green (G), and blue (B) disposed below the organic light-emitting layer 21. ) The image is displayed while passing through the color filter layers (CR, CG, CB).

In general, the power efficiency of an organic light emitting display device is an important variable that determines the power consumption required to drive the device. If power efficiency is improved, not only can the desired brightness be achieved with a small current, but there is also an advantage in extending the device lifespan.

For this reason, several methods have been proposed to improve the power efficiency of organic light emitting display devices. In particular, one method is to improve the extraction efficiency of light generated from organic light emitting diodes.

This is because the light generated from the organic light emitting diode is trapped inside the organic light emitting diode due to the high refractive index of the transparent electrode (ITO) and the organic layer, resulting in low light extraction efficiency.

To overcome these limitations, methods of placing micro-lenses or nano-sized structures on the outside of organic light-emitting diodes are being developed.

The purpose of the present invention is to provide an organic light emitting display device and a method of manufacturing the same that improve the light extraction efficiency of the organic light emitting diode by arranging a plurality of lens-shaped dot patterns on the electrode of the organic light emitting diode.

In addition, the present invention provides an organic light emitting display device in which brightness is improved by arranging a plurality of dot patterns for out-coupling on an organic light emitting diode electrode without an additional process and a method of manufacturing the same, for another purpose. There is.

The organic electroluminescent display device of the present invention to solve the problems of the prior art as described above includes a substrate divided into white (W), red (R), green (G), and blue (B) sub-pixel (SP) areas. It includes a thin film transistor disposed in each sub-pixel region of the substrate, and white (W), red (R), green (G), and blue (B) color filter layers disposed in each sub-pixel region. and an organic light emitting diode disposed in each sub-pixel area, wherein the organic light emitting diode includes a first electrode, a plurality of dot patterns disposed on the first electrode, and a plurality of dot patterns disposed on the first electrode and the dot pattern. By including an organic light-emitting layer disposed in and a second electrode disposed on the organic light-emitting layer, the light extraction efficiency of the organic light-emitting diode is improved.

In addition, the method of manufacturing an organic light emitting display device of the present invention includes providing a substrate divided into a plurality of white (W), red (R), green (G), and blue (B) sub-pixel regions, Forming a thin film transistor for each sub-pixel region on the substrate, wherein white (W), red (R), green (G), and blue (B) colors are applied to each sub-pixel region of the substrate on which the transistor is formed. A step of forming color filter layers, wherein a first electrode is formed in each sub-pixel area to correspond to the white (W), red (R), green (G) and blue (B) color filter layers, and It includes forming a plurality of dot patterns on a substrate on which the first electrode and the dot pattern are formed, and forming a bank layer to expose the first electrode, wherein the first electrode, the dot pattern, and It includes forming an organic light-emitting layer on the bank layer, and forming a second electrode on the organic light-emitting layer, thereby forming a plurality of electrodes for out-coupling on the organic light-emitting diode electrode without an additional process. There is an effect of improving luminance by arranging dot patterns.

The organic light emitting display device and its manufacturing method of the present invention have the effect of improving the light extraction efficiency of the organic light emitting diode by arranging a plurality of lens-shaped dot patterns on the electrode of the organic light emitting diode.

In addition, the organic light emitting display device and its manufacturing method of the present invention have the effect of improving brightness by arranging a plurality of dot patterns for out-coupling on the organic light emitting diode electrode without an additional process.

1 is a diagram showing the pixel structure of a general organic light emitting display device.
FIG. 2 is a cross-sectional view taken along line I-I' of FIG. 1.
Figure 3 is a diagram showing the pixel structure of an organic light emitting display device according to the present invention.
Figure 4 is a cross-sectional view of a pixel of an organic light emitting display device according to the present invention.
Figure 5 is an enlarged cross-sectional view of area A of Figure 4.
Figure 6 is a diagram showing the structure of a dot pattern according to another embodiment of the present invention.
7A to 7C are diagrams showing the manufacturing process of the organic light emitting display device of the present invention.
FIGS. 8A to 8D are diagrams illustrating a manufacturing process of a dot pattern for out-coupling on an electrode of an organic light emitting diode according to the present invention.
Figure 9 is a diagram for explaining light extraction in the electrode area of an organic light-emitting diode according to the present invention.
10A to 10D are diagrams illustrating dot patterns for out-coupling formed in each pixel area according to other embodiments of the present invention.

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. These 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.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as ‘after’, ‘after’, ‘after’, ‘before’, etc., ‘immediately’ or ‘directly’ Non-consecutive cases may also be included unless ' 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, embodiments of the present invention will be described in detail with reference to the drawings. And in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numerals refer to like elements throughout the specification.

Figure 3 is a diagram showing the pixel structure of the organic light emitting display device according to the present invention, and Figure 4 is a cross-sectional view of the pixel of the organic light emitting display device according to the present invention.

Referring to Figures 3 and 4, in the organic electroluminescent display device of the present invention, a plurality of gate lines 103 and data lines 105 intersect to display white (W), red (R), green (G) and Defines blue (B) sub-pixels (SP: Sub Pixel). The white (W), red (R), green (G), and blue (B) sub-pixels (SP) are defined as one pixel (Pixel).

A thin film transistor (TFT) is disposed in each sub-pixel (SP) area where the gate line 103 and the data line 105 intersect.

In addition, the white (W), red (R), green (G), and blue (B) sub-pixel areas include a white color filter layer (CW), a red color filter layer (CR) to correspond to the organic light emitting diode (OLED), respectively, A green color filter layer (CG) and a blue color filter layer (CB) are disposed.

For convenience of explanation, TFT is described as a driving transistor connected to an organic light-emitting diode, but since multiple switching transistors and driving transistors are arranged in each sub-pixel (SP) area, in some cases, it does not mean only one thin film transistor; It may refer to all transistors in the area where thin film transistors are formed.

The driving transistor (TFT) includes a channel layer 104 disposed on a substrate 100, a gate electrode 101 disposed to overlap the channel layer 104 with a gate insulating film 102 interposed therebetween, and the channel layer. It includes source and drain electrodes 107a and 107b respectively electrically connected to 104.

The channel layer 104 may be formed of a semiconductor layer including a crystalline silicon film and an ohmic layer, or may be formed of an oxide semiconductor layer.

In addition, the source and drain electrodes 107b and 107a are disposed to face each other with the channel layer 104 interposed, and are connected to the channel layer through contact holes formed in the gate insulating layer 102 and the interlayer insulating layer 112. It is electrically connected to (104).

A protective film 113 and a planarization film 114 are disposed on the driving transistor (TFT). Between the protective film 113 and the planarization film 114, a white color filter layer (CW) and a red color filter layer are formed for each sub-pixel area. (CR), green color filter layer (CG), and blue color filter layer (CB) are disposed, respectively.

In particular, the white color filter layer (CW) can be used as a white color filter layer (CW) without forming a separate color filter pattern because the planarization film 114 is transparent.

Organic light emitting diodes (OLEDs) are arranged on the planarization film 114 for each white (W), red (R), green (G), and blue (B) sub-pixel (SP) region. An organic light emitting diode consisting of a white pixel electrode 250, an organic light emitting layer 221, and an electrode 270 is disposed in the white (W) sub-pixel area, and a red pixel electrode 251 is disposed in the red (R) sub-pixel area. , an organic light emitting diode composed of an organic light emitting layer 221 and an electrode 270 is disposed, and in the green (G) sub-pixel area, an organic light emitting diode composed of a green pixel electrode 252, an organic light emitting layer 221, and an electrode 270 is disposed. A diode is disposed, and an organic light emitting diode consisting of a blue pixel electrode 253, an organic light emitting layer 221, and an electrode 270 is disposed in the blue (B) sub-pixel area.

In the present invention, out-coupling to improve light extraction is applied to the white (W), red (R), green (G), and blue (B) pixel electrodes (250, 251, 252, 253). Dot patterns (DP: Dot Patterns) are placed for structure.

Therefore, the present invention has the effect of improving light extraction efficiency by the dot pattern (DP) formed in the organic light emitting diode. That is, the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 are one with a dot pattern (DP) disposed on each electrode. It forms an electrode, and the dot pattern DP may have various structures such as a lens shape, a triangular pyramid, a sphere with a circular cross-section, a shape with an elliptical cross-section, and a prism structure.

In addition, the term 'dot pattern' used in the present invention refers to a form of pattern in which unconnected dots are repeatedly formed at a certain distance horizontally and vertically, depending on the size or size of the dots. It is not limited by shape. This is different from a straight grid pattern, because a grid pattern orthogonal to each other is undesirable because the light emitting area is excessively limited.

In the present invention, when the dot pattern (DP) is formed of an opaque metal or a material with low transparency, it is preferably set to 25% or less of the total light emitting area, but when it is formed of a transparent material, there is no limit to the total area (25 %~75%).

The period of the dot patterns DP, which represents the horizontal and vertical distance between each dot pattern DP, is preferably 250 to 1,000 nm. If the period of the dot pattern (DP) is less than 250 nm, it is undesirable because the period of the pattern may be smaller than the wavelength of light and the pattern cannot be manufactured reproducibly. If it exceeds 1,000 nm, there is a diffraction effect, but there is no scattering effect. This is undesirable because there are cases where the dot pattern itself acts as a medium.

Additionally, the dot pattern DP may have different spacing around the edges of the sub-pixel (SP) and the center area based on the sub-pixel (SP) area. For example, in the area around the edges, the spacing of the dot patterns (DP) can be placed at 250 nm to 300 nm, and as you move toward the center area, the spacing of the dot patterns (DP) can be placed at 800 to 1000 nm. In the same way, on the contrary, It can be placed.

Accordingly, the number of dot patterns (DP) per unit area in the area around the edge of the sub-pixel (SP) can be formed to be greater than the number of dot patterns (DP) per unit area in the center area, and vice versa. You can.

In this way, varying the distribution of the dot pattern (DP) for each region has the effect of adjusting the light extraction efficiency required in the sub-pixel (SP) region. Additionally, when there is a light distortion structure adjacent to the sub-pixel (SP), there is an advantage in that light extraction efficiency within the sub-pixel (SP) area can be varied.

In addition, it can be applied even when different light extraction efficiencies are required for each white (W), red (R), green (G), and blue (B) sub-pixel (SP).

A bank layer 210 is disposed between the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 to partition each sub-pixel area. Accordingly, in the sub-pixel area, the bank layer 210 is removed, and the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 are externally exposed. It has an exposed structure.

In addition, in the present invention, white (W), red (R), green (G), and blue (B) color filter layers (CW, CR, CG, CB) are arranged in each sub-pixel area, and the organic light emitting layer ( 221 and the electrode 270 are disposed on the front surface of the substrate 100.

That is, the organic light emitting layer 221 and the electrode 270 also exist on the bank layer 210 and are commonly used in organic light emitting diodes formed in each sub-pixel (SP) region.

Therefore, the organic light-emitting layer 221 is formed of an organic light-emitting layer that generates white light, and includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL). It can be included. The hole transport layer may further include an electron blocking layer (EBL), and the electron transport layer (ETL) can be formed using low molecular materials such as PBD, TAZ, Alq3, BAlq, TPBI, and Bepp2.

In the present invention, each of the white (W), red (R), green (G), and blue (B) pixel electrodes (250, 251, 252, 253) is provided with a dot pattern to have an out-coupling structure. By forming (DP), there is an effect of improving light extraction efficiency in each sub-pixel area.

In particular, the dot pattern DP can improve the luminance of light generated from each organic light-emitting diode by scattering light generated from the organic light-emitting layer 221 and minimizing light leakage to the side area.

In addition, as described above, when the optical luminance of the organic light emitting diode disposed in each sub-pixel area increases, a low driving voltage can be applied, which has the effect of reducing power consumption.

In addition, since the same luminance can be achieved even at a low driving voltage as at a high driving voltage, the device lifespan can be prevented from being shortened due to heat generation.

Figure 5 is an enlarged cross-sectional view of area A of Figure 4, and Figure 6 is a diagram showing the structure of a dot pattern according to another embodiment of the present invention.

Referring to FIG. 5, an organic light emitting diode (OLED) is disposed on the planarization film 114 in the white (W) sub-pixel area, and the organic light emitting diode includes a white (W) pixel electrode 250 and a plurality of dot patterns (DP). ), an organic light-emitting layer 221, and an electrode 270.

The dot pattern DP is arranged to improve the efficiency of extracting light generated from the organic light emitting diode and is formed to contact the upper surface of the white (W) pixel electrode 250. In addition, as shown in FIG. 3, the dot patterns (DP) for the out-coupling structure are white (W), red (R), green (G), and blue (B) sub-pixels (SP). ) can be placed in each area.

The number of dot patterns (DP) arranged in each sub-pixel area, their spacing, and the shape of the pattern may be appropriately changed according to required specifications. For example, according to the required specifications, the area occupied by the entire dot patterns (DP) is specified compared to the area of the sub-pixel (SP), and the number of dot patterns (DP) corresponding to the area of the specified dot pattern (DP) is specified. can be formed in the sub-pixel area.

Additionally, as shown in FIG. 6, the dot patterns DP formed in the sub-pixel SP area may be formed as first and second dot patterns DP1 and DP2 having different sizes.

In addition, although not shown in the drawing, dot patterns DP may be formed at different intervals from the edge area of the sub-pixel (SP) area to the center area of the sub-pixel (SP) area based on FIG. 3. .

For example, the dot pattern DP may be formed more densely in an area around the edge of the sub-pixel SP area than in the center area, or vice versa.

In addition, relatively small dot patterns (second dot patterns DP2 in FIG. 6) are formed in the area around the edges of the sub-pixel (SP) area, and dot patterns that become relatively larger as they move toward the center area. (The first dot pattern DP1 in FIG. 6) can be formed. Likewise, it can be formed in reverse.

As such, the present invention has the effect of improving light extraction efficiency by directly forming dot patterns for out-coupling on the pixel electrode of the organic light-emitting diode.

7A to 7C are diagrams showing the manufacturing process of the organic light emitting display device of the present invention, and FIGS. 8A to 8D are diagrams showing the manufacturing process for out-coupling on the electrode of the organic light emitting diode according to the present invention. This is a diagram showing the manufacturing process of a dot pattern.

Referring to FIGS. 7A to 8D, the organic electroluminescent display device of the present invention is on a substrate 100 in which white (W), red (R), green (G), and blue (B) sub-pixel regions are partitioned. After forming the semiconductor layer, the channel layer 104 of the switching transistor or driving transistor is formed according to a mask process.

Although not shown in the drawing, a buffer layer formed of a single layer of silicon oxide (SiOx) or a double layer of silicon nitride (SiNx) and silicon oxide (SiOx) may be formed on the substrate 100 before forming the channel layer 104.

Additionally, although not shown in the drawing, a shield layer for blocking light may be formed on the substrate 100 corresponding to the transistor. The shield layer is used to prevent light from entering the channel layer of the thin film transistor and generating leakage current even when the thin film transistor is in an off state.

The semiconductor layer may be formed as a semiconductor layer including a crystalline silicon film and an ohmic layer, or as an oxide semiconductor layer.

The oxide semiconductor layer may be made of an amorphous oxide containing at least one of indium (In), zinc (Zn), gallium (Ga), or hafnium (Hf). For example, when forming a Ga-In-Zn-O oxide semiconductor through a sputtering process, individual targets formed of In2O3, Ga2O3, and ZnO can be used, or a single target of Ga-In-Zn oxide can be used. Additionally, when forming an hf-In-Zn-O oxide semiconductor through a sputtering process, individual targets formed of HfO2, In2O3, and ZnO can be used, or a single target of Hf-In-Zn oxide can be used.

As described above, when the channel layer 104 is formed on the substrate 100, the gate insulating film 102 and the gate metal film are sequentially formed on the entire surface of the substrate 100, and then the channel layer 104 is formed according to a mask process. A gate electrode 101 is formed on the upper gate insulating film 102.

The gate insulating film 102 can be formed as a single layer of silicon oxide (SiOx) or by sequentially depositing silicon nitride (SiNx) and silicon oxide (SiOx).

The gate metal film may include aluminum (Al), aluminum alloy (Al alloy), tungsten (W), copper (Cu), nickel (Ni), chromium (Cr), molybdenum; A double-layer structure containing a metal film or an alloy of these materials, or at least two of low-resistance opaque conductive materials such as Mo), titanium (Ti), platinum (Pt), tantalum (Ta), etc. The above metal films may be formed into a stacked structure.

Then, an interlayer insulating film 112 is formed on the substrate 100, and a contact hole is formed on the upper part of the channel layer 104 corresponding to the area where source/drain electrodes will be formed according to a mask process.

As described above, when the interlayer insulating film 112 is formed, the source/drain metal film is formed on the front surface of the substrate 100, and the source electrode 107b and the drain electrode 107a are formed according to the mask process to form a switching thin film transistor or Completing the driving thin film transistor.

The source electrode 107b and the drain electrode 107a are electrically connected through a contact hole formed by removing part of the gate insulating film 102 and the interlayer insulating film 112 on the channel layer 104.

The source/drain metal film may be made of a low-resistance opaque conductive material such as aluminum, aluminum alloy, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, etc. In addition, it can be formed as a multi-layer structure in which transparent conductive materials such as indium tin oxide (ITO) and indium zinc oxide (IZO) and opaque conductive materials are stacked.

As described above, when the driving thin film transistor (TFT) is formed on the substrate 100, a protective film 113 is formed on the entire surface of the substrate 100, and is formed on the protective film 113 to correspond to each sub-pixel area. White (W), red (R), green (G), and blue (B) color filter layers (CW, CR, CG, CB) are formed.

The red (R), green (G), and blue (B) color filter layers (CR, CG, CB) can be formed using color resin, and the white (W) color filter layer (CW) is a transparent insulating material. Alternatively, the planarization film 114 formed later can be used as a white (W) color filter layer (CW) without forming a separate color filter layer.

Then, a planarization film 114 is formed on the entire surface of the substrate 100, and then a contact hole process is performed to expose a portion of the drain electrode 107a according to a mask process.

As described above, when the planarization film 114 is formed on the substrate 100, the first and second metal films 245 and 243 are sequentially formed on the entire surface of the substrate 100, and then a diffraction mask or halftone is applied. Using a mask, white (W), red (R), green (G), and blue (B) pixel electrodes (250, 251, 252, 253) are formed in each sub-pixel area and a dot pattern (DP) on each electrode. ) is formed.

Accordingly, a plurality of dot patterns DP are formed in each of the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253. As described in FIGS. 5 and 6, the dot patterns DP may be formed in various sizes and with different densities for each area.

In addition, the first metal film 245 is formed of a transparent conductive material such as ITO, ITZO, and IZO, and the second metal film 243 is formed of a material with excellent etch selectivity compared to the first metal film 245. It can be. For example, when the first metal film 245 is ITO, the second metal film 243 may be formed of IZO.

As described above, when the first metal film 245 and the second metal film 243 are formed on the substrate 100, the white (W) and red (R) colors are applied to each pixel area using a diffraction mask or a halftone mask. ), green (G), and blue (B) pixel electrodes (250, 251, 252, 253) and dot patterns (DP) are formed.

For the manufacturing method of the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 and the dot pattern (DP), refer to FIGS. 8A to 8D. Detailed explanation is as follows.

The first and second metal films 245 and 243 are sequentially formed on the planarization film 114, and then a photosensitive film is formed on the entire surface of the substrate 100, and exposed and exposed using a diffraction mask or halftone mask. Proceed with the development process.

When the exposure and development processes are completed, first photosensitive films 400 of different thicknesses are formed on the second metal film 243. A thick area of the first photoresist film 400 is an area where a dot pattern DP will be formed.

As described in the present invention, when the sizes of the formed dot patterns DP are different from each other or when the dot patterns DP are formed differently, the width of the photosensitive film patterns formed to be thick in the first photosensitive film 400 These may be different.

Then, a primary etching process is performed using the first photoresist film 400 as a mask to form the white (W) pixel electrode 250 in the sub-pixel area. At this time, red (R), green (G), and blue (B) pixel electrodes 251, 252, and 253 are formed in other sub-pixel areas.

As described above, when the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 are formed in each sub-pixel area, an ashing process is performed. proceeds to form a second photosensitive film 401 on the second metal film 243.

Then, a secondary etching process is performed using the second photoresist film 401 as a mask to form a dot pattern DP on the white (W) pixel electrode 250. At this time, dot patterns DP are also formed on the red (R), green (G), and blue (B) pixel electrodes 251, 252, and 253.

As described above, since the first and second metal films 245 and 243 are made of materials with excellent etch selectivity, when the second metal film 243 is etched, the first metal film 245 The white (W) pixel electrode 250 is not damaged by etching.

Additionally, since different etching solutions can be used in one mask process, there is an advantage that a separate mask process is not required to form the dot pattern (DP).

As described above, when the dot pattern (DP) is formed on the white (W) pixel electrode 250, the second photoresist film 401 is removed using a stripper.

Therefore, in the present invention, in the mask process of forming the white (W), red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 without additional processes, a mask process is performed on each electrode. It has the effect of forming a dot pattern (DP).

That is, the present invention has the effect of improving the light extraction efficiency of the organic light-emitting diode by implementing an out-coupling structure in the organic light-emitting diode without any additional process.

As described above, the white (W), red (R), green (G), and blue (B) pixel electrodes (250, 251, 252, 253) and dot patterns (DP) are formed on the substrate 100. Once formed, as shown in FIG. 7C, an insulating layer is formed on the entire surface of the substrate 100, and then a bank layer 210 is formed to partition each sub-pixel area.

A portion of the edge of the bank layer 210 overlaps a portion of the edge of each of the white (W), red (R), green (G), and blue (B) pixel electrodes (250, 251, 252, and 253). It can be.

Then, an organic light emitting layer 221 and a metal film are formed on the entire surface of the substrate 100 to form an electrode 270, thereby completing an organic light emitting diode (OLED).

The organic light-emitting layer 221 may be a low-molecular or high-molecular organic layer. When a low-molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an emission layer (EML) are formed. , Electron Transport Layer (ETL), Electron Injection Layer (EIL), etc. can be formed by stacking them in a single or complex structure, and usable organic materials include copper phthalocyanine (CuPc), N,N'-Di(naphthalene-1-yl)-N,N'-diphenyl-benzidine: NPB), Tris It can be applied in a variety of ways, including -8-hydroxyquinoline aluminum (tris-8-hydroxyquinoline aluminum) (Alq3). These low-molecular-weight organic layers are formed by vacuum deposition.

In the case of a polymer organic layer, it can usually have a structure comprised of a hole transport layer (HTL) and an emitting layer (EML). In this case, PEDOT is used as the hole transport layer, and poly-phenylenevinylene (PPV)-based and polyfluorene are used as the emitting layer. )-based, etc., can be used, and can be formed by screen printing or inkjet printing methods.

Such an organic layer is not necessarily limited to this, and of course, various embodiments can be applied.

Additionally, the light emitting layer (EML) of the organic light emitting layer 221 may be formed of an organic material that generates white light.

The organic light emitting display device and its manufacturing method of the present invention have the effect of improving the light extraction efficiency of the organic light emitting diode by arranging a plurality of lens-shaped dot patterns on the electrode of the organic light emitting diode.

In addition, the organic light emitting display device and its manufacturing method of the present invention have the effect of improving brightness by arranging a plurality of dot patterns for out-coupling on the organic light emitting diode electrode without an additional process.

Figure 9 is a diagram for explaining light extraction in the electrode area of an organic light emitting diode according to the present invention, and Figures 10a to 10d show out-coupling in each pixel area according to other embodiments of the present invention. ) This is a diagram showing how the dot pattern for is formed.

Referring to FIGS. 9 to 10D, in the present invention, as shown in FIG. 8D, the upper surface of the white (W) pixel electrode 250 forms a flat horizontal surface, and dot patterns (DP) in the form of convex lenses are formed on it. It is placed. The other red (R), green (G), and blue (B) pixel electrodes 250, 251, 252, and 253 and the dot patterns DP formed thereon are also formed in the same structure.

As shown in FIG. 9, in the present invention in which a convex dot pattern (DP) is formed on the horizontal white (W) pixel electrode 250, the first light (L1) passing through the dot pattern (DP) is The out-coupling effect of the dot pattern (DP) has the effect of minimizing light scattered to the side area of the organic light emitting diode.

In addition, since the upper surface of the white (W) pixel electrode 250 is horizontal between the dot patterns (DP), scattering of the second light (L2) that transmits only the white (W) pixel electrode 250 can be minimized. There is a possible effect.

As such, the present invention has the effect of maximizing light extraction efficiency by forming dot patterns for out-coupling on the electrodes of the organic light-emitting diode.

In the present invention, as shown in FIG. 3, dot patterns (DP) are applied to all of the white (W), red (R), green (G), and blue (B) sub-pixels (SP). can be formed.

In addition, as shown in FIG. 10A, a dot pattern (DP) is formed only in the red (R), green (G), and blue (B) sub-pixels (SP) excluding the white (W) sub-pixel (SP). , As shown in FIG. 10B, dot patterns DP can be formed only in the white (W) and red (R) sub-pixels (SP).

Additionally, as shown in FIGS. 10C and 10D, the dot pattern (DP) is applied only to the white (W) and green (G) sub-pixels (SP) or the white (W) and blue (B) sub-pixels (SP). can be formed.

Although not shown in the drawing, a dot pattern (SP) is formed only in one of the white (W), red (R), green (G), and blue (B) sub-pixels (SP), or the red (R) and green ( G) A dot pattern (SP) can be formed only in the sub-pixel (SP) or the green (G) and blue (B) sub-pixels (SP).

As such, in the present invention, dot patterns (DP) are selectively arranged for each white (W), red (R), green (G), and blue (B) sub-pixel (SP), thereby producing different light for each sub-pixel area. It has the effect of realizing extraction efficiency.

The organic light emitting display device and its manufacturing method of the present invention have the effect of improving the light extraction efficiency of the organic light emitting diode by arranging a plurality of lens-shaped dot patterns on the electrode of the organic light emitting diode.

In addition, the organic light emitting display device and its manufacturing method of the present invention have the effect of improving brightness by arranging a plurality of dot patterns for out-coupling on the organic light emitting diode electrode without an additional process.

100: substrate 102: gate insulating film
104: Channel layer 112: Interlayer insulating film
101: gate electrode 107b: source electrode
107a: drain electrode 113: protective film
114: planarization film 210: bank layer
221: organic light emitting layer 270: electrode
DP: dot pattern

Claims (12)

delete delete delete delete delete Providing a substrate divided into a plurality of white (W), red (R), green (G), and blue (B) sub-pixel areas;
forming a thin film transistor for each sub-pixel area on the substrate;
forming white (W), red (R), green (G), and blue (B) color filter layers in each sub-pixel area of the substrate on which the transistor is formed;
successively forming first and second metal films on the substrate;
forming a photoresist film on the second metal film and forming a first photoresist film using a halftone mask or a diffraction mask;
An etching process is performed using the first photoresist film as a mask, and an organic light emitting diode is formed in each sub-pixel area to correspond to the white (W), red (R), green (G), and blue (B) color filter layers. forming a first electrode;
forming a second photoresist film through an ashing process on the first photoresist film, and then performing an etching process using the second photoresist film as a mask to form a plurality of dot patterns on the first electrode;
forming a bank layer on the substrate on which the first electrode and the dot pattern are formed to expose the first electrode;
forming an organic light emitting layer on the first electrode, the dot pattern, and the bank layer; and
Comprising the step of forming a second electrode on the organic light emitting layer,
A method of manufacturing an organic light emitting display device, wherein the upper surface of the first electrode of the organic light emitting diode corresponding to the space between the dot patterns has a horizontal surface.
delete The method of claim 6, wherein the first metal film is formed of ITO, and the second metal film is formed of IZO.
The method of claim 6, wherein the dot patterns are divided into a first dot pattern and a second dot pattern, and the first and second dot patterns have different sizes.
The method of claim 6, wherein the dot patterns are arranged at different intervals on the first electrode.
The method of claim 6, wherein the dot patterns are arranged at different intervals from an edge area to a center area of the sub-pixel area.
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