KR102076962B1 - Organic light emitting display device and manufacturing method thereof - Google Patents

Abstract

A pixel defining layer (PDL) formed between a substrate, a plurality of first electrodes formed on the substrate, the plurality of first electrodes to distinguish the plurality of first electrodes from each other, and the plurality of firsts A light emitting layer formed on the electrode, a second electrode formed on the light emitting layer, and a filter part formed on the second electrode, wherein the filter part includes a black matrix layer having an opening and an emboss formed on the opening and the black matrix layer. Provided is an organic light emitting display device including the formed color filter layer.

Description

Organic light-emitting display device and its manufacturing method {ORGANIC LIGHT EMITTING DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF}

The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device and a method of manufacturing the same, which simplify the manufacturing process and improve viewing angle characteristics.

Organic light emitting display devices have been spotlighted as next generation displays due to advantages such as low voltage driving, light weight, wide viewing angle, and fast response speed. In particular, research on a flexible display device using an organic light emitting diode has been actively conducted in recent years.

Such an organic light emitting display has a problem in that visibility is reduced due to light reflected from the device when the device is viewed in an environment where external light such as sunlight is present.

As an example for solving this problem, a method of attaching a polarizer or a polaroid film on the encapsulation layer of the organic light emitting display may be applied as shown in FIG. 1.

The organic light emitting display device illustrated in FIG. 1 includes a substrate 110, a first electrode 120 disposed on the substrate 110, a pixel definition layer 130 for separating the first electrode 120, and the Light emitting layers 140R, 140G, and 140B formed on the first electrode 120, a second electrode 150 formed on the light emitting layer 140, and a protective layer 160 formed on the second electrode 150. The polarizer or polaroid film polarized in one direction is disposed on the protective layer 160 to prevent reflection of external light.

By attaching a polarizing plate or a polarizing film to the organic light emitting display as shown in Figure 1 it can prevent reflection due to external light. However, there is a problem that the extraction efficiency of light generated in the light emitting layer is reduced due to the polarizing plate or polarizing film.

Thus, one example of the present invention is to provide an organic light emitting display device that improves the viewing angle characteristic while improving the problem of deterioration of visibility caused by external light.

A pixel defining layer (PDL) formed between a substrate, a plurality of first electrodes formed on the substrate, the plurality of first electrodes to distinguish the plurality of first electrodes from each other, and the plurality of firsts A light emitting layer formed on the electrode, a second electrode formed on the light emitting layer, and a filter formed on the second electrode, wherein the filter part comprises a black matrix layer having an opening and an emboss formed on the opening and the black matrix layer. Provided is an organic light emitting display device including the formed color filter layer.

An organic layer may be formed on the color filter layer.

The emission layer may include a red emission layer, a green emission layer, and a blue emission layer, and the color filter layer may include a red filter, a green filter, and a blue filter in correspondence with the emission layer.

The emission layer may include a white light emitting material and a red filter, a green filter, and a blue filter disposed on the white light emitting material.

The black matrix may be formed at a position corresponding to an upper portion of the pixel definition layer.

The black matrix may be formed of a material having light absorption.

The embossing may be formed in the form of a convex lens.

The embossing may be formed in the form of a concave lens.

The embossing may be formed at a position corresponding to an upper portion of the emission layer.

The embosses may be formed one per pixel separated by the pixel defining layer.

Two or more embosses may be formed per pixel separated by the pixel defining layer.

The refractive index of the organic layer may be formed of a material of 1.2 or more and less than 1.5.

The refractive index of the organic layer may be formed of a material of 1.5 or more and 1.8 or less.

The angle between the emboss and the substrate may have a value in the range of 15 degrees to 70 degrees.

The substrate may include a plurality of thin film transistor layers and an insulating layer formed on the plurality of thin film transistor layers.

A protective layer may be formed between the second electrode and the filter unit.

At least one of a hole injection layer and a hole transport layer may be formed between the first electrode and the light emitting layer.

At least one of an electron injection layer and an electron transport layer may be formed between the emission layer and the second electrode.

Forming a black matrix having an opening on the thin film encapsulation, applying a color filter layer on the black matrix, exposing the color filter layer, developing the color filter layer, forming an organic layer on the color filter layer It provides a method for manufacturing an organic light emitting display device comprising the step of planarizing.

In the exposing step, an organic light emitting display device is manufactured using a mask.

An organic light emitting display device according to an example of the present invention can improve external light visibility and viewing angle characteristics. In addition, the organic light emitting display device according to an example of the present invention can simplify the manufacturing process.

1 is a view showing an organic light emitting display device having a conventional polarizing plate or a polarizing film attached thereto.
2 illustrates an organic light emitting display device according to an embodiment of the present invention.
3 illustrates an organic light emitting display device according to another exemplary embodiment of the present invention.
4A is an example of an embossed form formed in the organic layer in one embodiment according to FIG. 2.
Figure 4b is another example of the embossed form formed on the organic layer in one embodiment according to FIG.
5A to 5I illustrate a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.
6A and 6B are examples of comparing light emission efficiency with one embodiment of the present invention and a comparative example.
7 illustrates an example of comparing viewing angle characteristics of an organic light emitting display device according to an embodiment of the present invention and a comparative example.
8 is a diagram illustrating an organic light emitting display device according to another exemplary embodiment of the present invention.
9 is a diagram illustrating an organic light emitting display device according to another exemplary embodiment of the present invention.
10A to 10I illustrate a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present invention.

Hereinafter, examples of the present invention will be described in detail with reference to specific drawings. The scope of the invention is not limited to the examples or figures described below. There may be various equivalents and modifications from the embodiments described below and the embodiments shown in the drawings.

For reference, in the drawing, each component and its shape may be briefly drawn or exaggerated for clarity. Elements denoted by the same reference numerals in the drawings means the same element.

In addition, when a layer or component is described as being on another layer or 'on' of a component, not only when the layer or component is disposed in direct contact with the other layer or component, It means including all until the case where a 3rd layer is interposed.

2 illustrates an organic light emitting display device according to an embodiment of the present invention.

In the organic light emitting diode display of FIG. 2, a substrate 210, a plurality of first electrodes 220 formed on the substrate 210, a pixel defining layer 230 formed between the plurality of first electrodes 220, and the The light emitting layers 240R, 240G and 240B formed on the first electrode 220, the second electrode 250 formed on the light emitting layer 240, the protective layer 260 formed on the second electrode 250, and the The filter layer 270 is formed on the passivation layer 260. The filter unit 270 may include a color filter layer 272R formed on a black matrix 271 formed at a position corresponding to the pixel defining layer 230 and a protective layer 260 on which the black matrix 271 is patterned. 272G, 272B).

The organic light emitting diode display of FIG. 3 may include a black matrix 271, color filter layers 272R, 272G, and 272B and an organic layer 273 in the filter unit 275 formed on the passivation layer 260. .

The substrate 210 may be formed of various materials such as glass, metal, plastic, or may be formed using a flexible material. The substrate 210 should be formed of a light transmissive material when the image is a bottom emission in the direction of the substrate. However, in the case of top emission, the substrate 210 may not necessarily be formed of a light transmissive material. Hereinafter, a case of a top emission type organic light emitting display device will be described by way of example to simplify the description.

The first electrode 220 may be formed on the substrate 210. The first electrode 220 is gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper ( Cu), palladium (Pd), titanium (Ti) and a reflective film formed of a compound thereof may be included. The reflective film may further include a transparent film formed of indium tin oxide (ITO), indium zinc oxide (IZO), or the like having a high work function. In addition, the first electrode 220 may be formed to include various materials known in the art. In addition, the first electrode 220 may serve as an anode electrode.

Although not shown in FIG. 2, a thin film transistor and an insulating layer protecting the thin film transistor may be further included between the substrate 210 and the first electrode 220. In this case, at least one thin film transistor may be formed for each pixel, and may be electrically connected to the first electrode 220.

The pixel defining layer 230 overlapping an end of the first electrode 220 to divide the first electrode 220 in pixel units between the plurality of first electrodes 220. pixel define layer (PDL) may be formed. That is, the pixel definition layer 230 may electrically block the plurality of first electrodes 220 as an insulating layer.

The pixel defining layer 230 may cover only a portion of the upper surface of the first electrode 220, and the remaining portion of the first electrode 220 not covered by the pixel defining layer 230 may form an opening. Can be. The light emitting layer 240 to be described later may be formed on a region defined by the opening. Of course, the light emitting layer 240 does not need to be formed only in a region defined by the opening, but may be formed on a portion of the pixel definition layer 230 as shown in FIG. 2.

For example, the organic light emitting display device of FIG. 2 is a top emission type, and the second electrode 250 may be provided as a transmissive electrode. For example, thinly formed metals having a low work function, that is, alkali metals such as lithium (Li) and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca) and strontium (Sr) and compounds thereof The second electrode may be formed of a transflective film. A transparent conductive film, such as indium tin oxide (ITO) and indium zinc oxide (IZO: Indium Zinc Oxide), may be further formed on or below the metal semi-transmissive film. The second electrode 250 may serve as a cathode.

The light emitting layer 240 may be provided between the first electrode 220 and the second electrode 250. Although not shown in FIG. 2, a hole transfer layer (HTL) and a hole injection layer (HIL) may be formed between the first electrode 220 and the light emitting layer 240. In addition, an electron transport layer (ETL) and an electron injection layer (EIL) may be formed between the emission layer 240 and the second electrode 250.

The emission layer 240 may include a red emission layer 240R, a green emission layer 240G, and a blue emission layer 240B.

The emission layer 240 may include a white emission layer and a red color filter, a green color filter, and a blue color filter formed on the white emission layer.

A protective layer 260 may be provided on the second electrode 250 to protect the light emitting layer 240 from an external environment such as moisture or oxygen.

The protective layer 260 may be formed of a thin film encapsulation layer or an encapsulated transparent substrate such as encap glass, in which a plurality of organic layers and an inorganic layer are laminated.

When the protective layer 260 is a thin film encapsulation layer, the protective layer 260 may include a plurality of organic material layers and a plurality of inorganic material layers that are alternately stacked. The organic material layer may include an acrylate-based material, and the inorganic layer may include an oxide-based material.

The black matrix 271 may be formed on the passivation layer 260 at a position corresponding to the pixel definition layer 230.

The black matrix 271 is formed using an opaque metal such as chromium (Cr) or chromium oxide (CrOx) or a black resin-based material that absorbs light.

The black matrix 271 may absorb light exposed to the organic layer during the manufacturing process of the organic light emitting display device. Therefore, the exposure amount is different between the region where the black matrix 271 is formed and the region where the black matrix 271 is not formed. That is, the black matrix may serve to adjust the exposure amount for each region in the exposure process.

In addition, the black matrix 271 may be formed in the non-pixel area of the organic light emitting diode display to block light leakage at the boundary of the pixel area, thereby improving contrast.

The black matrix 271 is formed by applying an opaque metal such as chromium (Cr) or chromium oxide (CrOx) or a black resin-based material that absorbs light onto the protective layer 260, and then masking the mask. It can be formed through a photo lithography (photo lithograpy) method that is patterned through the process.

In addition, the black matrix 271 may be formed by a vacuum deposition method using a micro transfer molding method. In addition, the black matrix 271 may be formed through various process methods known in the art.

Color filter layers 272R, 272G, and 272B are formed on the black matrix 271 and the openings of the black matrix 271.

The color filter layers 272R, 272G, and 272B may be formed by a process such as pigment dispersion, dyeing, electrodeposition, or thermal transfer. In addition, it may be formed using a color filter forming method known in the art.

The color filter layers 272R, 272G, and 272B may have a lens-shaped emboss convex in the light emitting surface direction. The angle between the embossed surface and the surface horizontal to the substrate may range from 10 degrees to 70 degrees. In addition, the emboss can form one emboss per pixel, and can form two or more embosses per pixel.

The convex lens-shaped emboss is formed on the color filter layers 272R, 272G, and 272B using a photo-lithograpy process.

The color filters 272R, 272G, and 272B are uniformly applied to the light emitting layers 240R, 240G, and 240B on the protective layer 260 on which the black matrix 271 is patterned.

A mask is formed at a position corresponding to the patterned position of the black matrix 271 and exposed using an exposure apparatus such as a stepper.

As described above, an emboss in the form of a convex lens may be formed on the color filter layers 272R, 272G, and 272B through a process of developing after an exposure process using a mask.

The organic light emitting display device of FIG. 3 further includes an organic layer 273 on the organic light emitting display device of FIG. 2.

The refractive index of the organic layer 273 may be formed of a material having a refractive index smaller than the refractive index 1.5 of the color filter layers 272R, 272G, and 272B. Preferably it can be formed using a material having a refractive index of 1.2 or more and less than 1.5. In addition, the organic layer 273 may be formed of a material of a transparent material.

FIG. 4A illustrates an example of an emboss shape formed in the color filter layers 272R, 272G, and 272B according to the exemplary embodiment of FIG. 2. As shown in FIG. 4A, one emboss per pixel may be formed in the color filter layers 272R, 272G, and 272B.

FIG. 4B is another example of an emboss form formed in the color filter layers 272R, 272G, and 272B in the embodiment of FIG. 2. As shown in FIG. 4B, two or more embosses may be formed in each of the color filter layers 272R, 272G, and 272B.

5A to 5I illustrate a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

In an organic light emitting display device according to an embodiment of the present invention, (a) forming a plurality of first electrodes 220 on the substrate 210, (b) between the plurality of first electrodes 220. Forming a pixel definition layer 230, (c) forming light emitting layers 240R, 240G, and 240B on the first electrode 220, and (d) forming a second electrode on the light emitting layer 240. 250, forming (e) forming a protective layer 260 on the second electrode 250, and (f) forming a black matrix pattern 271 on the protective layer 260. (g) applying color filters 272R, 272G and 272B onto the protective layer 260 patterned with the black matrix 271 and (h ~ i) applying the color filters 272R, 272G and 272B. Exposure is performed using a mask and then developed to form an emboss in the form of a convex lens.

In addition, an organic layer 273 may be formed on the color filter layers 272R, 272G, and 272B, and the organic light emitting display device manufactured in this case is as shown in FIG.

<Light extraction efficiency>

The light extraction simulation model for checking the light extraction efficiency of the organic light emitting display device according to an embodiment of the present invention can be set as follows.

For comparison, an organic light emitting display device including a flat color filter may be used as a comparative example. Here, the refractive index of the color filter is 1.5, and the color filter generally used is used.

The organic light emitting diode display according to the exemplary embodiment of the present invention may include a color filter layer having embossed convex lenses in the light emitting surface direction (see FIG. 3). The angle formed by the emboss with the substrate is 60 degrees, and the refractive index of the color filter layer on which the emboss is formed is 1.5. An organic layer is formed on the color filter layer of the convex lens type, and the refractive index of the organic layer is 1.2.

6A and 6B are simulation diagrams showing the amount of light emitted to the front surface of the organic light emitting display device of the comparative example and the organic light emitting display device according to an example of the present invention, respectively.

When the color filter layer having the convex lens-shaped emboss is formed in the light emitting surface direction as in the embodiment of the present invention, the amount of light emitted to the front may be improved by about 115% than when the emboss is not formed as in the comparative example. Can be.

<Improve view angle>

7 illustrates an example in which viewing angle characteristics of an organic light emitting display device according to an example of the present invention and a comparative example are compared.

In the graph shown in FIG. 7, the x-axis direction represents an angle and the y-axis direction represents an amount of change in luminance. That is, the luminance is measured in the range of 0 degrees to 60 degrees on the basis of an imaginary line perpendicular to the light emitting surface, and is a graph showing the amount of change in the luminance ratio at each angle to the luminance at the zero degree. Therefore, the smaller the amount of change due to the change in angle, the better the viewing angle characteristic.

In FIG. 7, the WAD value of the comparative example is 0.03 at 60 degrees, and the WAD value of the example of the present invention is 0.018 at 60 degrees. That is, it can be seen that the viewing angle characteristic of the organic light emitting device including the color filter layer in which the emboss is formed as in the embodiment is improved compared to the structure without the emboss.

8 is a diagram illustrating an organic light emitting display device according to another exemplary embodiment of the present invention.

The organic light emitting diode display of FIG. 8 includes a substrate 310, a plurality of first electrodes 320 formed on the substrate 310, a pixel defining layer 330 formed between the plurality of first electrodes 320, and the Light emitting layers 340R, 340G, and 340B formed on the first electrode 320, the second electrode 350 formed on the light emitting layer 340, the protective layer 360 formed on the second electrode 350, and the The filter unit 370 formed on the passivation layer 360 is included. The filter unit 370 may include a black matrix 371 formed at a position corresponding to the pixel defining layer 330 and a color filter layer formed on the protective layer 360 on which the black matrix 371 is patterned. 372R, 372G, 372B).

9 may include a black matrix 371, color filter layers 372R, 372G, and 372B, and an organic layer 273 in the filter unit 375 formed on the passivation layer 360. .

Description of overlapping components of the organic light emitting display device of FIGS. 8 and 9 will be omitted.

Color filter layers 372R, 372G, and 372B are formed on the black matrix 371 and the openings of the black matrix 371.

The color filter 272 may be formed by a process such as pigment dispersion, dyeing, electrodeposition, or thermal transfer. In addition, it may be formed using a color filter forming method known in the art.

The color filter layers 372R, 372G, and 372B may have a lens-shaped emboss in the light exit surface direction. The angle between the embossed surface and the surface horizontal to the substrate may range from 10 degrees to 70 degrees. In addition, the emboss can form one emboss per pixel, and can form two or more embosses per pixel.

The method of forming the concave lens-shaped emboss on the color filter layers 372R, 372G, and 372B uses a photo-lithograpy process.

The color filters 372R, 372G, and 372B corresponding to the light emitting layers 340R, 340G, and 340B are uniformly coated on the protective layer 360 on which the black matrix 371 is patterned.

A mask is formed at a corresponding position on the position where the light emitting layers 340R, 340G, and 340b are formed, and exposed using an exposure apparatus such as a stepper.

As described above, the concave lens-shaped emboss may be formed on the color filter layers 372R, 372G, and 372B after the exposure process using the mask.

The organic light emitting display device of FIG. 9 further includes an organic layer 373 on the organic light emitting display device of FIG. 8.

The refractive index of the organic layer 373 may be formed of a material having a refractive index greater than the refractive index 1.5 of the color filter layers 372R, 372G, and 372B. Preferably it can be formed using a material having a refractive index of 1.5 or more and 1.8 or less. In addition, the organic layer 373 may be formed of a material of a transparent material.

10A to 10C are diagrams for describing a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present invention.

5F, that is, (a) forming a plurality of first electrodes 320 on the substrate 310, and (b) a pixel defining layer 330 between the plurality of first electrodes 320. ), (C) forming the light emitting layers 340R, 340G, and 340B on the first electrode 320, and (d) forming the second electrode 350 on the light emitting layer 340. Steps (e) forming the protective layer 360 on the second electrode 350 and (f) forming the black matrix pattern 371 on the protective layer 360 are shown.

In FIG. 10A, color filters 372R, 372G, and 372B are applied onto the protective layer 360 on which the black matrix 371 is patterned. FIGS. 10B and 10C illustrate the color filters 372R, 372G, and 372B. The step of exposing using a mask and then developing to form an emboss in the form of a concave lens.

In addition, an organic layer 373 may be formed on the color filter layers 372R, 372G, and 372B, and an organic light emitting display device manufactured in this case is as shown in FIG.

110,210,310: substrate 120,220,320: first electrode
130, 230, 330: pixel defining layer 140, 240, 340: light emitting layer
150,250,350: second electrode 160,260,360: protective layer
270,275,370,375: filter layer 271,371: black matrix
272,372 color filter layer 273,373 organic layer

Claims (28)

Board;
A first electrode disposed on the substrate;
A pixel defining layer (PDL) having an opening exposing at least a portion of the first electrode;
A light emitting layer disposed on the first electrode;
A second electrode disposed on the light emitting layer;
A protective layer formed on the second electrode; And
A filter part disposed on the protective layer and including a light exit surface facing away from the substrate;
The light emitting surface includes an curved surface disposed on the opening. The method of claim 1, wherein the filter unit comprises a color filter layer disposed on the protective layer,
The color filter layer includes the curved surface. The organic light emitting display device of claim 1, wherein an organic layer is disposed on the filter unit. The organic light emitting display device of claim 1, wherein the light emitting layer comprises a red light emitting layer, a green light emitting layer, and a blue light emitting layer, and the filter unit includes a red filter, a green filter, and a blue filter corresponding to the light emitting layer. The organic light emitting display device of claim 1, wherein the light emitting layer comprises a white light emitting layer. The organic light emitting display device of claim 5, wherein the filter unit comprises a red filter, a green filter, and a blue filter disposed on the white light emitting layer. The organic light emitting display device of claim 1, wherein the light emitting layer comprises a blue light emitting layer, and the filter unit comprises a red filter and a green filter. The organic light emitting display device of claim 1, wherein the light emitting layer comprises a blue light emitting layer. The organic light emitting display device as claimed in claim 1 or 8, wherein the filter unit comprises a red filter and a green filter. The organic light emitting display device of claim 1, wherein the light emitting layer comprises at least one of a red light emitting layer, a green light emitting layer, and a blue light emitting layer. The organic light emitting display device of claim 1, wherein the filter unit comprises at least one of a red filter, a green filter, and a blue filter. The organic light emitting display device of claim 1, further comprising a black matrix disposed at a position corresponding to an upper portion of the pixel definition layer. The organic light emitting display device of claim 1, wherein the protective layer and the filter unit have a flat interface therebetween. The organic light emitting display device of claim 3, wherein the curved surface has a concave lens shape. The organic light emitting display device of claim 1, wherein the curved surface includes one lens shape per opening. The organic light emitting display device as claimed in claim 1, wherein the curved surface includes two or more lens shapes per opening. The organic light emitting display device of claim 3 or 14, wherein a refractive index of the organic layer is larger than a refractive index of the filter unit. 18. The organic light emitting display device according to claim 17, wherein the refractive index of the organic layer is 1.5 or more and 1.8 or less. The organic light emitting display device of claim 1, wherein an angle between the curved surface and the front surface of the substrate is 15 to 70 degrees. The organic light emitting display device of claim 1, further comprising: a plurality of thin film transistor layers disposed on the substrate and an insulating layer disposed on the plurality of thin film transistor layers. The organic light emitting display device of claim 1, wherein the passivation layer comprises at least one organic layer and at least one inorganic layer that are alternately stacked. Board;
A first electrode disposed on the substrate;
A pixel definition layer having an opening exposing at least a portion of the first electrode;
A light emitting layer disposed on the first electrode;
A second electrode disposed on the light emitting layer;
A protective layer disposed on the second electrode; And
A first layer disposed on the protective layer and including a light exit surface facing away from the substrate;
The light emitting surface includes an curved surface disposed on the opening. The organic light emitting display device of claim 22, wherein the curved surface has a concave lens shape. The organic light emitting display device according to claim 22 or 23, wherein a second layer is disposed on the first layer. The organic light emitting display device according to claim 24, wherein the second layer is an organic layer. The organic light emitting display device of claim 25, wherein the refractive index of the second layer is greater than the refractive index of the first layer. 27. The organic light emitting display device according to claim 26, wherein the refractive index of the second layer is 1.5 or more and 1.8 or less. 27. The organic light emitting display device as claimed in claim 26, wherein the refractive index of the first layer is 1.5.

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