KR102196889B1 - Organic Light Emitting Diode Display Device and Method for Manufacturing The Same - Google Patents

Abstract

An organic light emitting display device according to an aspect of the present invention includes a first substrate on which an organic light emitting device is located; A second substrate having a plurality of color conversion layers spaced apart from each other; And an intermediate layer positioned between the first substrate and the second substrate, wherein the intermediate layer includes a light blocking portion positioned between the color conversion layers.

Description

Organic Light Emitting Diode Display Device and Method for Manufacturing The Same}

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 including a color conversion layer and a method of manufacturing the same.

As the information age matures, the market for display devices that display information is developing at a rapid pace. Accordingly, research and development on display devices is active, and in particular, lightweight and thin flat panel displays are gaining great popularity.

Typical flat panel displays include a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode (OLED). Among them, organic light emitting diodes (OLEDs) are the ones that have seen remarkable growth recently in the field of research and development.

In the organic light emitting display device, when excitons are transferred to a ground state in an organic emission layer positioned between two electrodes, energy equal to the band gap of the organic material constituting the organic emission layer is emitted as light. Is displayed.

The organic light emitting display device is an RGB independent method in which organic materials emitting light of different colors are independently deposited for each pixel, and organic materials emitting white light are located in all pixels and have a color conversion layer for each pixel. There is a WRGB method that emits light.

1 is a cross-sectional view showing a part of a conventional WRGB type organic light emitting display device 100.

As shown in FIG. 1, the organic light emitting display device 100 includes a first substrate 110, an organic light emitting device 120, an encapsulation layer 130, an intermediate layer 140, a color conversion layer 150, and It includes 2 substrates 160.

The color including the color conversion member 151 and the black matrix 152 are sequentially stacked on the first substrate 110 and the organic light emitting device 120 and the encapsulation layer 130 are sequentially stacked on the second substrate 160 The conversion layer 150 is located. The first substrate 110 and the second substrate 160 face each other and are bonded through the intermediate layer 140. That is, the intermediate layer 140 is positioned between the color conversion layer 150 and the encapsulation layer 130.

The color conversion member 151 may be formed while overlapping the black matrix 152 on the second substrate 160 on which the black matrix 152 is first formed, and the black matrix 152 is generally the color conversion member 151 The height is lower than that, and thus, the color conversion member 151 is formed to cover the black matrix 152 at a portion where the color conversion member 151 and the black matrix 152 overlap.

When the color conversion layer 150 is formed as described above, a light leakage phenomenon occurs in which light emitted from the organic light emitting device 120 leaks to an adjacent pixel before passing through the color conversion layer 150 occurs, resulting in lower luminance. , There may be a problem in gradation expression.

An object of the present invention is to provide an organic light emitting display device capable of blocking light leakage between adjacent pixels as to solve the above problems.

An organic light emitting display device according to an aspect of the present invention for achieving the above object includes: a first substrate on which an organic light emitting device is located; A second substrate having a plurality of color conversion layers spaced apart from each other; And an intermediate layer positioned between the first substrate and the second substrate, wherein the intermediate layer includes a light blocking portion positioned between the color conversion layers.

According to another aspect of the present invention for achieving the above object, a method of manufacturing an organic light emitting display device includes forming an organic light emitting device on a first substrate; Forming a color conversion layer on the second substrate; Applying an intermediate layer forming material on the color conversion layer; Bonding the first substrate and the second substrate; And discoloring the intermediate layer positioned between the color conversion layers by irradiating light onto the second substrate.

According to the present invention, there is an effect of improving the efficiency of a process by forming a light-shielding portion capable of exerting the same effect as the black matrix only by irradiation of light without separately forming the black matrix.

In addition, according to the present invention, since the light blocking portion is formed adjacent to the thin film encapsulation layer, there is an effect of preventing light leakage between adjacent pixels.

In addition, according to the present invention, by preventing the light leakage phenomenon between adjacent pixels by the light blocking portion, it is possible to sufficiently secure a distance between the color conversion layer and the organic light emitting device, and accordingly, there are no restrictions on the encapsulation layer design and the substrate bonding process. , It has the effect of improving design freedom.

1 is a cross-sectional view showing a general organic light emitting display device;
2 is a cross-sectional view illustrating an organic light emitting display device according to an embodiment of the present invention;
3 is a cross-sectional view illustrating an organic light emitting display device according to another embodiment of the present invention; And
4A to 4D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

As shown in FIG. 2, the organic light emitting display device according to an embodiment of the present invention includes a first substrate 210, an organic light emitting device 220, an encapsulation layer 230, an intermediate layer 240, and a color conversion layer. 250 and a second substrate 260.

First, the first substrate 210 and the second substrate 260 may include glass, plastic, metal, or SUS (Steel Use Stainless), and may include a flexible material. It can also be included. For example, the first substrate 210 and the second substrate 260 are polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate ( Polyethyelenen Napthalate; PEN), Polyethyelene Terepthalate (PET), Polyphenylene Sulfide (PPS), Polyallylate, Polyimide, Polycarbonate (PC), Cellulose Triacetate ( TAC), Cellulose Acetate Propionate (CAP) may be included.

An organic light emitting device 220 is positioned on the first substrate 210. The organic light-emitting device 220 is a unit device in which the organic light-emitting layer 223 emits light, and includes a first electrode 221, a bank layer 222, an organic light-emitting layer 223, and a second electrode 224. The organic emission layer 223 is positioned between the first electrode 221 and the second electrode 224. A driving circuit (not shown) for driving the organic light-emitting device 220 may be further positioned between the first substrate 210 and the organic light-emitting device 220.

A first electrode 221 is positioned on the first substrate 210 for each pixel area PA. The bank layer 222 overlaps the edge of the first electrode 221, separates the pixel area PA, and defines the light emission area EA. An organic emission layer 223 is located on the bank layer 222, and a second electrode 224 is located on the organic emission layer 223.

The emission area EA is defined as a region in which the organic emission layer 223 contacts the first electrode 221 and the second electrode 224 or is a region in which the first electrode 221 is opened by the bank layer 222. Can be defined.

Meanwhile, holes are supplied from the first electrode 221, electrons are supplied from the second electrode 224, and the holes and electrons are supplied from the organic emission layer 223 to the first electrode 221 and It moves in the vertical direction that is the direction of the second electrode 224. Accordingly, the emission area EA may be defined as an area in which the organic emission layer 223 contacts the first electrode 221 and at the same time also contacts the second electrode 224. Alternatively, the emission area EA may be defined as an area in which the organic emission layer 223 overlaps the first electrode 221 and at the same time overlaps the second electrode 224.

In addition, since the second electrode 224 is positioned above the first electrode 221, the area of the area in which the organic emission layer 223 contacts the second electrode 224 is the area in the area in contact with the first electrode 221. Since it is smaller than the area, the emission area EA may be defined as an area in which the organic emission layer 223 contacts the second electrode 224. Alternatively, the emission area EA may be defined as an area in which the organic emission layer 223 overlaps the second electrode 224.

An encapsulation layer 230 is positioned on the organic light emitting device 220. The encapsulation layer 230 may have a thin film encapsulation layer structure in which an organic material layer for flattening by covering foreign substances such as particles that may be generated during a process and an inorganic material layer for preventing moisture penetration are alternately stacked. Alternatively, it may have a face seal structure including an organic layer preventing damage to the organic light emitting device 220 by particles and a plurality of inorganic layers surrounding the organic light emitting device 220 from above and below.

A color conversion layer 250 is positioned on the second substrate 260. The color conversion layers 250 are spaced apart from each other and correspond to each pixel area PA or the light emission area EA of each pixel area PA. The color conversion layer 250 changes light emitted from the light emission area EA of each pixel area PA into a desired color and emits it to the outside of the organic light emitting display device. Each light-emitting area EA of the organic light-emitting device 220 may emit white or a different color for each pixel area PA, and currently, FIG. 2 shows a white WRGB type organic light-emitting diode emitting white light. A display device is shown. However, the present invention is not limited thereto, and may be applied to an RGB type organic light emitting display device.

The color conversion layer 250 may basically include a red conversion layer (red), a green conversion layer (green), and a blue conversion layer (blue), and may include white, light blue, and dark blue. ), sky blue, magenta, yellow, and the like. The color configuration of the color conversion layer 250 may vary depending on the implementation method of the organic light emitting display device.

An intermediate layer 240 is positioned between the first substrate 210 and the second substrate 260, and the intermediate layer 240 bonds the first substrate 210 and the second substrate 260 together. Since the intermediate layer 240 bonds the first substrate 210 and the second substrate 260 to each other, it may include an epoxy or acrylate-based resin so as to have a bonding property of a resin. . More specifically, in FIG. 2, the intermediate layer 240 is positioned between the color conversion layer 250 and the encapsulation layer 230.

The intermediate layer 240 includes a transparent portion 241 and a light blocking portion 242. The transparent portion 241 corresponds to the color conversion layer 250 of each pixel area PA, and the light blocking portion 242 is positioned between the transparent portions 241 and between the color conversion layers 250. That is, a plurality of transparent portions 241 are provided and spaced apart from each other so as to correspond to the color conversion layer 250, and a plurality of light shielding portions 242 are also provided between the transparent portions 241 and are spaced apart from each other. The light blocking portions 242 are positioned between the color conversion layers 250 spaced apart from each other. The light blocking part 242 may serve as a black matrix in a conventional organic light emitting display device. Accordingly, the light blocking portion 242 may be disposed in a matrix shape with the transparent portion 241 interposed therebetween.

The light blocking part 242 may cross the intermediate layer 240 and contact the second substrate 260 and the encapsulation layer 230. The cross-section of the light blocking portion 242 may have a square shape with one end in contact with the second substrate 260 and the other end in contact with the encapsulation layer 230. Since the light blocking portion 242 is disposed long from the second substrate 260 to the encapsulation layer 230, a light leakage phenomenon in which light leaks into the adjacent pixel area PA can be prevented. The encapsulation layer 230 has a thin film encapsulation or face seal structure formed of a plurality of thin films, and their thickness is only a few micrometers, so the organic light-emitting device 220 It is very unlikely that the light emitted from the light emitting area EA of) may be emitted to the outside of the organic light emitting display device through the color conversion layer 250 of an adjacent pixel.

Since the light blocking part 242 is positioned between the color conversion layers 250 and the encapsulation layer 230 is formed, light leakage can be prevented, and accordingly, the light emitting area EA of the organic light emitting device 220 The open area OA, which is an area in which light is emitted to the outside of the organic light emitting display device, may be larger. Accordingly, the aperture ratio of the organic light emitting display device can be improved regardless of the area of the light emitting area EA. In addition, since the same or larger aperture ratio can be implemented even with the smaller light emitting area EA, it may be helpful to reduce power consumption.

As described above, the intermediate layer 240 includes a transparent portion 241 and a light blocking portion 242, and the light blocking portion 242 may be formed by discoloring the intermediate layer 240 after light having a specific wavelength is incident thereon. The characteristic that the absorption spectrum changes as the structure of a material changes by receiving light of a specific wavelength is called photochromic. Changing the absorption spectrum means that the material is discolored. Also, a material that changes color by receiving light is called a photochromic material. Accordingly, the intermediate layer 240 may be made of a photochromic material or may include a photochromic material.

There are various photochromic materials, but the photochromic material that can be used as the material of the intermediate layer 240 in the present invention should be an irreversible photochromic material. In addition, the intermediate layer 240 may be discolored by light having a wavelength smaller than the emission wavelength of the organic light emitting device 220, or may be discolored by light having a wavelength greater than the emission wavelength of the organic light emitting device 220. .

Since the intermediate layer 240 passes light in a region of visible rays emitted from the organic light emitting device 220, the intermediate layer 240 passes light outside the range of the light emitted from the organic light emitting device 220, for example The color may be discolored by infrared rays or ultraviolet rays, or by electromagnetic waves outside the visible light range. As the irreversible photochromic material, silver chloride (AgCl), diarylethene iridium (III) complex, bismuth oxychloride (Bismuth Oxychloride, BiOCl), and bismuth oxyiodide (Bismuth Oxyiodide, BiOI) And the like, but are not limited thereto.

Since the intermediate layer 240 is formed in a region exposed to light irradiation, it may be located from the second substrate 260 to the encapsulation layer 230 positioned at the top of the first substrate 210. That is, since the intermediate layer 240 is formed up to a region in contact with the first substrate 210 and the second substrate 260, light leakage between adjacent pixels is prevented. In addition, even if the space between the first substrate 210 and the second substrate 260 is sufficiently secured, light leakage does not occur. That is, even if a sufficient distance between the color conversion layer 250 and the organic light emitting device 220 is secured, light leakage does not occur, and thus design freedom can be secured.

In addition, the opening area OA of the color conversion layer 250 defined by the light blocking portion 242 of the intermediate layer 240 is a light emitting area EA defined by the bank layer 222 of the organic light emitting device 220 Can be larger than That is, since a larger opening area OA can be implemented as the light emitting area EA of the smaller organic light emitting device 220, power consumption can be reduced.

3 is a cross-sectional view illustrating an organic light emitting display device according to another embodiment of the present invention.

The embodiment shown in FIG. 3 is characterized in that, unlike the embodiment shown in FIG. 2, the cross section of the light shielding portion 242 has a trapezoidal shape whose width increases toward the first substrate 210. When light is irradiated to the second substrate 260 to form the light shielding part 242, the irradiation time of the light is adjusted so that the first substrate 210 is compared with the upper surface of the light shielding part 242 in the direction of the second substrate 260. A trapezoidal shape with a larger width of the lower surface, which is the side in the) direction, can be formed.

Since the light blocking part 242 is formed in a trapezoidal shape, light leakage between adjacent pixels can be better prevented, and the first substrate 210 and the second substrate are compared to the organic light emitting display device in the embodiment shown in FIG. 2. Even if a larger space between the 260 is secured, light leakage does not occur. Accordingly, it is possible to secure a greater degree of design freedom than in the organic light emitting display device in the embodiment illustrated in FIG. 2.

In addition, since the light shielding portion 242 is formed in a trapezoidal shape, a larger opening area OA can be implemented with a smaller emission area EA, and thus consumption is more than that of the organic light emitting display device in the embodiment shown in FIG. 2. The power reduction effect is greater.

4A to 4D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention.

First, as shown in FIG. 4A, an organic light-emitting device 220 and an encapsulation layer 230 are formed on the first substrate 210. First, a first electrode 221 is formed on the first substrate 210. When the first electrode 221 is an anode that supplies holes, it is formed of a transparent conductive oxide (TCO) having a high work function, and the first electrode 221 is In the case of a cathode that supplies electrons, it may be formed of a metal having a low work function. Depending on the material to be formed, the first electrode 221 may be formed using thermal deposition, vacuum deposition, and sputtering method.

An organic emission layer 223 is formed on the first electrode 221, and a second electrode 224 is formed on the organic emission layer 223. That is, the organic emission layer 223 may be positioned between the first electrode 221 and the second electrode 224. The second electrode 224 can be formed as a cathode when the first electrode 221 is an anode, and an anode when the first electrode 221 is a cathode, and is formed using thermal evaporation, vacuum evaporation, and sputtering methods. Can be.

The organic emission layer 223 may include a material emitting red, green, and blue light, or may include at least one or more of them to emit white light. Further, the organic emission layer 223 may include phosphorescent or fluorescent materials. The red-emitting material may include a host material containing CBP (carbazole biphenyl) or mCP (1,3-bis (carbazol-9-yl), PIQIr (acac) (bis (1-phenylisoquinoline) acetylacetonate) iridium), PQIr (acac) (bis (1-phenylquinoline) acetylacetonate iridium), PQIr (tris (1-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum) The material may be made of a material, but may be made of a fluorescent material including PBD:Eu(DBM)3(Phen) or Perylene, but is not limited thereto As a material emitting green, a host material including CBP or mCP may be used. Includes, and may be made of a phosphorescent material containing a dopant material containing Ir (ppy) 3 (factris (2-phenylpyridine) iridium), and unlike this, a fluorescent material containing Alq3 (tris (8-hydroxyquinolino) aluminum) The material emitting blue light includes a host material including CBP or mCP, and may be formed of a phosphorescent material including a dopant material including (4,6-F2ppy)2Irpic. Unlike this, spiro-DPVBi, spiro-6P, distillbenzene (DSB), distrylarylene (DSA), PFO-based polymer and PPV-based polymer may be made of a fluorescent material containing any one selected from the group consisting of At least one of the above materials may be formed by any one of a thermal evaporation method, a laser thermal transfer method, a screen printing method, and a vacuum deposition method.

An encapsulation layer 230 is formed on the organic emission layer 223, and the encapsulation layer 230 may be formed by alternately stacking organic and inorganic layers. The organic material layer is made of a material such as an acrylate, epoxy-based polymer, and imide-based polymer, and can be formed through a method such as screen printing and thermal evaporation, and the inorganic layer is It may be formed through various deposition methods including a method of forming the organic material layer with a material such as silicon oxide (SiOx) or silicon nitride (SiNx).

Next, as shown in FIG. 4B, a color conversion layer 250 is formed on the second substrate 260. The color conversion layer 250 is formed in a separate color in each pixel area PA, and may be formed of a photoresist suitable for each color. The color conversion layer 250 may be formed of red, green, and blue photoresists, and may be formed simultaneously by patterning photoresists of the same color. For example, when the pixel area PA emits red, green, and blue light, the color conversion layer 250 may be formed through a total of three photoresist patterning processes.

After the color conversion layer 250 is formed, a material for forming the intermediate layer 240 may be applied on the color conversion layer 250 to bond the first and second substrates 210 and 260.

Next, as shown in FIG. 4C, after the intermediate layer 240 is applied on the color conversion layer 250, the first substrate 210 and the second substrate 260 are bonded together. After bonding, the intermediate layer 240 is cured through heat curing and ultraviolet curing. The ultraviolet rays used in the curing process must be in a wavelength range irrelevant to color conversion of the intermediate layer 240. Alternatively, when ultraviolet rays used in the curing process are in a wavelength band in which color conversion of the intermediate layer 240 is possible, the curing process of the intermediate layer 240 and the color conversion process may be simultaneously performed.

Next, as shown in FIG. 4D, light is irradiated to the second substrate 260 so that the light is incident on the intermediate layer 240 positioned between the color conversion layers 250. The light may have a wavelength smaller than the emission wavelength of the organic light emitting device 220 or may have a wavelength greater than the emission wavelength of the organic light emitting device 220. Accordingly, the light irradiated to the second substrate 260 is ultraviolet rays having a wavelength smaller than that of visible light, or infrared rays having a wavelength greater than that of visible light, or in the visible region. It may be an external electromagnetic wave.

Those skilled in the art to which the present invention pertains will be able to understand that the above-described present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof.

Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

210: first substrate 220: organic light emitting device
221: first electrode 222: bank layer
223: organic emission layer 224: second electrode
230: encapsulation layer 240: intermediate layer
241: transparent part 242: light blocking part
250: color conversion layer 260: second substrate
PA: pixel area EA: light-emitting area
OA: open area

Claims (10)

An organic light-emitting device and a first substrate on which an encapsulation layer is disposed on the organic light-emitting device;
A second substrate having a plurality of color conversion layers spaced apart from each other; And
Including; an intermediate layer of an irreversible photochromic material positioned between the first substrate and the second substrate,
The middle layer
A light blocking part positioned between the color conversion layers; And
And a transparent portion positioned between the light blocking portions to correspond to the color conversion layer,
The light blocking portion has a column shape extending from the second substrate to the encapsulation layer on the first substrate,
An organic light emitting display device, wherein an upper surface of the light blocking part is in contact with the second substrate, and a lower surface of the light blocking part is in contact with the encapsulation layer on the first substrate. The method of claim 1,
An organic light emitting display device, wherein a cross section of the light blocking portion has a trapezoidal shape whose width increases toward the first substrate. The method of claim 1,
The opening area of the color conversion layer corresponds to a width of each of the color conversion layers implemented with at least one color of R, G, and B,
The light emitting region of the organic light emitting device corresponds to a bank layer on the first substrate and a width between the bank layer and the adjacent bank layer,
An organic light emitting display device, wherein the opening area of the color conversion layer is larger than the width of the emission area of the organic light emitting device. delete The method of claim 1,
The intermediate layer is an organic light emitting display device, characterized in that bonding the first substrate and the second substrate. delete The method of claim 1,
The organic light emitting display device, wherein the irreversible photochromic material is discolored by light having a wavelength greater or smaller than that of the organic light emitting device. The method of claim 1,
The organic light emitting device,
A first electrode and a second electrode on the first substrate; And
An organic light emitting display device comprising: an organic light emitting layer positioned between the first electrode and the second electrode. Forming an organic light emitting device on the first substrate;
Forming an encapsulation layer on the organic light-emitting device;
Forming a color conversion layer on the second substrate;
Applying an intermediate layer forming material on the color conversion layer;
Bonding the first substrate and the second substrate; And
After the bonding step, irradiating light to the second substrate to discolor the intermediate layer positioned between the color conversion layers to form a light blocking portion; Including,
The light shielding portion is characterized in that the column shape extending from the second substrate to the encapsulation layer on the first substrate,
A method of manufacturing an organic light emitting display device, wherein an upper surface of the light blocking part is in contact with the second substrate, and a lower surface of the light blocking part is in contact with the encapsulation layer on the first substrate. The method of claim 9,
The method of manufacturing an organic light emitting display device, wherein the light irradiated to the second substrate is light having a wavelength greater or less than that of the organic light emitting device.

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