KR20150077261A - Organic light emitting display device and method of manufacturing the same - Google Patents

Abstract

Provided are an organic light emitting display device and a method for manufacturing an organic light emitting display device. A color filter is arranged on a substrate of the organic light emitting display device. An overcoating layer is arranged on the color filter, and includes multiple convex parts and multiple concave parts. The multiple convex parts and the multiple concave parts are arranged to overlap the color filter on the color filter. A step buffering layer is arranged on the overcoating layer. The step buffering layer has refractive index greater than the refractive index of the overcoating layer, and buffers steps formed by the multiple convex parts and multiple concave parts. An organic light emitting device including an anode, an organic light emitting layer, and a cathode is arranged on the step buffering layer. The step buffering layer having greater refractive index than the refractive index of the overcoating layer is arranged between the overcoating layer and the anode so that light emitted from the organic light emitting layer is focused within the total reflection critical angle in both ITO mode and a substrate mode and multiple reflection is available, thereby increasing a light extract efficiency. Also, multiple concave parts and multiple convex parts of the overcoating layer are arranged to overlap the color filter and are arranged between the anode and the color filter, thereby removing blurring and ghost effect, and also removing light interference caused by a round polarizing plate. Also, short between an anode and a cathode formed on the upper part of the coating layer is prevented by using a step buffering layer to buffer the steps of the overcoating layer.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode (OLED) display and a method of manufacturing the same. More particularly, the present invention relates to an organic light emitting diode

The organic light emitting display device is a self-emission type display device, unlike a liquid crystal display device, a separate light source is not required, and thus it can be manufactured in a light and thin shape. Further, the organic light emitting display device is not only advantageous from the viewpoint of power consumption by low voltage driving, but also excellent in color implementation, response speed, viewing angle, and contrast ratio (CR), and is being studied as a next generation display.

The light emitted from the organic light emitting layer of the organic light emitting display passes through various elements of the organic light emitting display and is emitted outside the organic light emitting display. However, the light emitted from the organic light emitting layer does not exit outside the organic light emitting display device, and the light trapped inside the organic light emitting display device exists, which causes a problem in the light extraction efficiency of the organic light emitting display device. In order to improve the light extraction efficiency of the OLED display, a method of attaching a micro lens array (MLA) to the outside of the substrate of the OLED display is used.

 [Related Technical Literature]

1. Organic electroluminescent display device and method of manufacturing the same (Patent Application No. 10-2012-0100222)

The bottom emission type organic light emitting display device refers to an organic light emitting display device in which light emitted from an organic light emitting device is emitted to a lower portion of the organic light emitting display device, Refers to an organic light emitting display device that emits in the direction of a bottom surface of a substrate on which a thin film transistor for driving an apparatus is formed. The light emitted from the organic emission layer of the bottom emission type organic light emitting display device is divided into ITO / organic mode (hereinafter referred to as 'ITO mode'), substrate mode and air mode . The air mode refers to light extracted from the organic light emitting layer to the outside of the organic light emitting display device, and the substrate mode refers to light trapped in the organic light emitting display device due to total reflection, And the ITO mode refers to light confined in the organic light emitting display device by total reflection, light absorption, or the like in the anode, which is generally formed of ITO among light emitted from the organic light emitting layer. In the bottom emission type organic light emitting display, light confined in the organic light emitting display as an ITO mode is about 50% of the light emitted from the organic light emitting layer. Light trapped in the organic light emitting display as a substrate mode is emitted About 80% of the light emitted from the organic light emitting layer is trapped in the organic light emitting display device, only about 20% of the light is extracted to the outside, and the light extraction efficiency of the organic light emitting display device Improving is a very important research area.

In order to solve the problem of the light extraction efficiency of the organic light emitting display as described above, a technique of attaching the MLA to the outside of the substrate and extracting the light totally reflected by the refractive index difference between the substrate and the outside of the substrate to improve the light extraction efficiency Lt; / RTI >

However, when the MLA is attached to the outside of the substrate, since the thickness of the substrate is generally much larger than the distance between the substrate and the anode, the light emitted from the specific pixel is extracted to the outside of the substrate through the MLA located in a region other than the pixel , Blurring, and / or ghosting may occur. In addition, even when the MLA is attached to the entire outer surface of the substrate, the light emitted from a specific pixel may be extracted to the outside of the substrate through the MLA located in a region other than the pixel, and blurring and / or ghosting may occur. When the MLA is attached to the outside of the organic light emitting diode display, the light reflected from the MLA to the inside of the organic light emitting diode display is reflected by the circularly polarizing plate. The light is canceled and the light extraction efficiency is reduced. In addition, when the MLA is disposed outside the substrate, only the light corresponding to the substrate mode among the light confined in the organic light emitting display can be extracted, and extraction of light corresponding to the ITO mode is impossible.

Accordingly, the inventors of the present invention have proposed a novel structure capable of improving the light extraction efficiency in the bottom emission type organic light emitting display device in order to solve the problems that may occur when the MLA is arranged outside the substrate as described above Respectively.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic light emitting display and an organic light emitting display having improved device efficiency by improving light extraction efficiency without deteriorating image quality and image quality.

Another problem to be solved by the present invention is to provide an organic light emitting display and a method of manufacturing an organic light emitting display in which the light extraction efficiency is improved and the lifetime is increased.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

There is provided an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention. A color filter is formed on the substrate. The overcoat layer is formed on the color filter and includes a plurality of convex portions or a plurality of concave portions. The plurality of convex portions and the plurality of concave portions are formed to overlap with the color filter on the color filter. A step relaxation layer is formed on the overcoat layer. The step difference reducing layer has a refractive index larger than the refractive index of the overcoat layer and alleviates the steps generated by the plurality of convex portions and the plurality of concave portions. An organic light emitting element including an anode, an organic light emitting layer and a cathode is formed on the step reducing layer. Since the step relaxation layer having the refractive index larger than the refractive index of the overcoat layer is formed between the overcoat layer and the anode, the light emitted from the organic light emitting layer is gathered in the total reflection critical angle in both the ITO mode and the substrate mode, So that the light extraction efficiency can be increased. Further, since the plurality of convex portions and the plurality of concave portions of the overcoat layer are arranged so as to overlap with the color filter, and disposed between the anode and the color filter, the blurring phenomenon and the ghosting phenomenon are eliminated, and the optical interference by the circularly polarizing plate is also removed . Further, by using the step reducing layer for alleviating the step of the overcoat layer, it is possible to prevent the anode and the cathode formed on the overcoat layer from being shorted to each other.

There is provided an organic light emitting display including a plurality of concave portions having a cut-off shape and a filling layer according to an embodiment of the present invention. A color filter formed on the substrate is formed. The overcoat layer is formed on the color filter and includes a concave portion having a plurality of cut edges. A concave portion having a plurality of hem cut-off portions is formed to overlap with the color filter on the color filter, and exposes the color filter. A filling layer is formed on the overcoat layer. The filling layer has a refractive index larger than the refractive index of the overcoat layer and fills at least a part of the inside of the concave portion having a plurality of cut ends. The side surface of the concave portion of which the plurality of hems are cut off is an inclined curved surface. An organic light emitting device including an anode, an organic light emitting layer, and a cathode is formed on the filling layer. Since the refractive index of the filling layer formed between the overcoat layer and the anode is greater than the refractive index of the overcoat layer, the light emitted from the organic light emitting layer can be prevented from being trapped in the ITO mode and the substrate mode. In addition, a plurality of concave depressed portions of the hem may be formed to expose the color filter, so that light extraction efficiency in the ITO mode can be improved. In addition, the filling layer may fill at least a part of the inside of the concave portion having a plurality of cut-outs of the overcoat layer so that the anode, the organic light emitting layer and the cathode formed on the filling layer may be formed with an embossing structure, The current efficiency, driving voltage, power efficiency, etc. of the device can be improved.

There is provided a method of manufacturing an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention. A method of manufacturing an organic light emitting display includes forming a color filter on a substrate, forming an overcoat layer including a plurality of convex portions or a plurality of concave portions overlapping the color filter on the color filter, Forming a stepped relaxed layer having a refractive index larger than that of the stepped relief layer to alleviate a stepped portion by a plurality of convexities or a plurality of recesses, and sequentially stacking an anode, an organic light emitting layer and a cathode on the stepped relaxed layer, And forming a device. It is possible to prevent the anode and the cathode formed on the overcoat layer from being shorted to each other by forming the step reducing layer on the overcoat layer.

The details of other embodiments are included in the detailed description and drawings.

1A is a cross-sectional view illustrating an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention.
1B is an enlarged cross-sectional view of the X region of FIG. 1A.
FIG. 1C is an enlarged cross-sectional view illustrating a shape of an overcoat layer and a step relaxation layer different from FIG. 1B of the organic light emitting diode display according to an exemplary embodiment of the present invention.
FIG. 1D is an enlarged cross-sectional view illustrating an additional insulating layer of an OLED display according to an exemplary embodiment of the present invention. Referring to FIG.
1E is a cross-sectional view illustrating an organic light emitting display including an overcoat layer including a plurality of convex portions and a step reducing layer according to an embodiment of the present invention.
FIG. 2A is a cross-sectional view illustrating an organic light emitting diode display including a plurality of concave portions and a filling layer having a cut-off end according to an exemplary embodiment of the present invention.
2B is an enlarged cross-sectional view of the X region of FIG. 2A.
3 is a flowchart illustrating a method of manufacturing an OLED display device including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention.
4A to 4F are cross-sectional views illustrating a method of manufacturing an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

An element or layer is referred to as being another element or layer "on ", including both intervening layers or other elements directly on or in between.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

Like reference numerals refer to like elements throughout the specification.

The sizes and thicknesses of the individual components shown in the figures are shown for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the components shown.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other partially or entirely and technically various interlocking and driving is possible as will be appreciated by those skilled in the art, It may be possible to cooperate with each other in association.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

1A is a cross-sectional view illustrating an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention. 1B is an enlarged cross-sectional view of the X region of FIG. 1A. 1A and 1B, an OLED display 100A includes a substrate 110A, a thin film transistor 120A, a color filter 150A, an overcoat layer 160A, a step relaxation layer 170A, (140A). The organic light emitting display 100A shown in FIGS. 1A and 1B is a bottom emission organic light emitting display.

A thin film transistor 120A including a gate electrode 121A, an active layer 122A, a source electrode 123A and a drain electrode 124A is formed on a substrate 110A formed of an insulating material. A gate electrode 121A is formed on the substrate 110A and a gate insulating layer 131A for insulating the gate electrode 121A and the active layer 122A is formed on the gate electrode 121A and the substrate 110A, An active layer 122A is formed on the gate insulating layer 131A and an etch stopper 132A is formed on the active layer 122A and the active layer 122A and the etch stop layer 132A are formed. A source electrode 123A and a drain electrode 124A are formed on the aperture 132A. The source electrode 123A and the drain electrode 124A are electrically connected to the active layer 122A in a manner in contact with the active layer 122A and are formed on a partial area of the etch stopper 132A. For convenience of description, only the thin film transistors among the various thin film transistors that can be included in the organic light emitting display 100A are shown in this specification. In this specification, the thin film transistor 120A is described as an inverted staggered structure, but a thin film transistor having a coplanar structure may also be used.

A passivation layer 133A is formed on the thin film transistor 120A and a color filter 150A is formed on the passivation layer 133A. The color filter 150A is for converting light emitted from the organic light emitting layer 142A into color, and may be one of a red color filter, a green color filter, and a blue color filter. The color filter 150A may be formed of a material having a refractive index of about 1.5.

The color filter 150A is formed on the passivation layer 133A at a position corresponding to the light emitting region. Here, the light emitting region means a region where the organic light emitting layer 142A emits light by the anode 141A and the cathode 143A, and the color filter 150A is formed at a position corresponding to the light emitting region, Means that the color filter 150A is arranged to prevent the blinking phenomenon and the ghost phenomenon from occurring due to the mutual mixing of the emitted light. For example, the color filter 150A is formed so as to overlap the light emitting region, and may have a size smaller than the light emitting region. The position and size of the color filter 150A are not limited to the size and position of the light emitting region but also the distance between the color filter 150A and the anode 141A and the distance between the color filter 150A and the concave portion of the overcoat layer 160A The distance between the light emitting region and the protrusion 163E, the distance between the light emitting region and the light emitting region, and the like.

An overcoat layer 160A is formed on the color filter 150A and the passivation layer 133A. The overcoat layer 160A is formed of an insulating material having a refractive index of about 1.5. For example, the overcoat layer 160A may include an acrylic resin, an epoxy resin, a phenol resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, , A polyphenylene sulfide based resin, benzocyclobutene, and a photoresist, but it is not limited thereto and may be formed of any insulating material having a refractive index of about 1.5.

The overcoat layer 160A includes a plurality of concave portions 161A formed to overlap with the color filter 150A and a first connecting portion 162A connecting the concave portions 161A adjacent to each other. The plurality of concave portions 161A are hemispherical or semispherical. Figs. 1A and 1B are cross-sectional views of a portion having a maximum height in a hemispherical shape or semi-ellipsoid shape of a plurality of recesses 161A, and a plurality of recesses 161A are shown in a semicircular shape. Referring to FIG. 1B, the diameter 2R of each of the plurality of recesses 161A is about 1 to 5 占 퐉, and the height D is about 1 to 4 占 퐉. Referring to FIG. 1B, the first connecting portion 162A is a high portion between the concave portions 161A adjacent to each other. The overcoat layer 160A functions as a planarization layer in a portion where a plurality of recesses 161A are not formed.

The step reducing layer 170A is formed on the overcoat layer 160A. The step reducing layer 170A is formed of a material having a refractive index larger than that of the overcoat layer 160A. The refractive index of the step reducing layer 170A may be about 1.7 to 2.0. Specifically, the step difference reducing layer 170A is a layer in which nano particles having a size of several tens nm, such as titanium oxide (TiO2), zirconium oxide (ZrO2) and the like, having a refractive index larger than that of the polymer binder are dispersed in the polymer binder Or nanoparticles such as titanium oxide (TiO2), zirconium oxide (ZrO2), etc. having a refractive index larger than the refractive index of the photoresist are dispersed in the photoresist.

The step reducing layer 170A is a layer for alleviating a stepped portion by the plurality of concave portions 161A of the overcoat layer 160A. 1B, the thickness h1 of the step reducing layer 170A formed on the concave portion 161A of the overcoat layer 160A is set to be greater than the thickness h1 of the overcoat layer 170A in order to alleviate the stepped portion by the plurality of recesses 161A The step difference reducing layer 170A is formed so as to be larger than the thickness h2 of the step reducing layer 170A formed on the first connecting portion 162A of the step portion 160A.

Referring to Figs. 1A and 1B, the step reducing layer 170A is formed so that its top surface becomes an unplated surface. That is, the upper surface portion of the step difference reducing layer 170A formed on the concave portion 161A of the overcoat layer 160A and the upper surface portion of the step difference reducing layer 170A formed on the first connecting portion 162A of the overcoat layer 160A Are on different planes from each other, and the upper surface of the step reducing layer 170A is formed to be an unplated surface.

The organic light emitting element 140A and the bank 136A including the anode 141A, the organic light emitting layer 142A and the cathode 143A are formed on the step reducing layer 170A. Specifically, an anode 141A for supplying a hole to the organic light emitting layer 142A is formed on the upper surface of the step reducing layer 170A, an organic light emitting layer 142A is formed on the anode 141A, A cathode 143A for supplying electrons to the organic light emitting layer 142A is formed on the organic light emitting layer 142A. The anode 141A, the organic luminescent layer 142A and the cathode 143A are formed along the top surface of the organic luminescent layer 142A, which is a non-flattened surface, and have uneven top and bottom surfaces. The anode 141A is formed of a transparent conductive oxide having a high work function such as ITO, and the cathode 143A is formed of a metallic material having a low work function. Since the organic light emitting diode display 100A is a bottom emission organic light emitting diode display device, the metallic material constituting the cathode 143A must be a material having excellent reflectivity.

As the resolution of the organic light emitting display increases, the pixel size of the organic light emitting display decreases and the number of pixels increases. Therefore, in a high-resolution organic light emitting diode display, the power required to emit light of the same luminance is higher than that of an organic light emitting display having a relatively low resolution, and the lifetime of the organic light emitting diode may become a problem. Accordingly, in the organic light emitting diode display 100A according to an embodiment of the present invention, the organic light emitting layer 142A is formed to have an unperformed top and bottom surfaces, so that the organic light emitting layer 142A has a comparative The voltage and current for emitting the light of the same luminance are reduced, the power is also reduced, and the lifetime of the organic light emitting element 140A can be increased.

The aspect ratio of the cathode 143A formed on the concave portion 161A of the overcoat layer 160A of the cathode 143A of the organic light emitting element 140A is about 0.5 to 0.7. Referring to FIG. 1B, the aspect ratio of the cathode 143A is a value obtained by dividing the height M of the cathode 143A formed on the concave portion 161A by the radius N of the cathode 143A.

The organic light emitting layer 142A is formed as a tandem white structure in which a plurality of organic light emitting layers are stacked to emit white light. The organic luminescent layer 142A includes a first organic luminescent layer for emitting blue light and a second organic luminescent layer formed on the first organic luminescent layer to emit light of a color which is mixed with blue and becomes white. The second organic luminescent layer may be, for example, an organic luminescent layer that emits yellow-green light.

In general, a micro-cavity effect is applied to increase the light extraction efficiency of an OLED display. The micro-cavity effect means a method of increasing the light extraction efficiency using the light reflectivity of the electrode and the optical constructive interference. The micro-cavity effect is realized by a method of satisfying a specific optical condition in which a wavelength corresponding to a specific color is reflected and reflected between the reflective electrode and the transflective electrode. It is possible to select the wavelength to be reinforced by adjusting the distance between the reflective electrode and the transflective electrode, that is, the thickness of the organic light emitting layer. Theoretically, when an integral multiple of a wavelength corresponding to a specific color is an even multiple of the thickness of the organic light emitting layer, constructive interference of a wavelength corresponding to a specific color occurs. At this time, the condition of the constructive interference can be expressed as follows.

2nd = mλ

(n, m = integer, m = order of wavelength, d = thickness of organic light emitting layer, lambda = reference wavelength at which constructive interference occurs)

In order to apply the micro cavity effect to the organic light emitting device, first, the optimal point of the region where the light corresponding to the wavelength to be reinforced by the transflective electrode and the reflective electrode emits light is calculated. Then, the thickness of the entire organic light emitting layer is calculated in consideration of a constructive interference condition. When the organic light emitting device is designed to reflect this, the light extraction efficiency of a wavelength corresponding to a specific color can be improved.

Due to optical conditions for implementing such a micro-cavity effect, the thickness of the organic light emitting layer is limited. For example, in the case where the organic light emitting layer is formed by stacking two organic light emitting layers to emit white light, in order to increase the light extraction efficiency by applying the micro-cavity effect, It should have the thickness of the light emitting layer. That is, in the case where the organic light emitting layer is formed by stacking two organic light emitting layers to emit white light, in order for the organic light emitting device to meet the optical condition for realizing the micro-cavity effect, Or more. Furthermore, as the number of stacked organic luminescent layers increases, the thickness of the organic luminescent layer increases dramatically depending on optical conditions for implementing the micro-cavity effect. As the thickness of the organic light emitting layer increases, the manufacturing cost and manufacturing time of the organic light emitting device increase, and the driving voltage and power consumption for driving the organic light emitting display also increase.

As a result, when the micro-cavity effect is applied to increase the light extracting effect, the driving voltage and the power consumption due to the increase in the thickness of the organic light emitting layer increase and the power efficiency decreases. do.

However, the organic light emitting diode display 100A according to the embodiment of the present invention increases the light extraction efficiency by applying the overcoat layer 160A and the step difference reducing layer 170A instead of the micro cavity effect. Accordingly, in order to increase the light extraction efficiency, the organic light emitting diode display 100A according to the embodiment of the present invention does not need to optimize the thickness of the organic light emitting layer 142A to the optical condition for realizing the micro-cavity effect. As a result, the thickness of the organic light emitting layer 142A can be remarkably reduced. That is, the organic light emitting diode 140A of the organic light emitting diode display 100A according to an exemplary embodiment of the present invention may have a thickness of the organic light emitting layer 142A of 350 nm or less.

The light emitted from the first organic light emitting layer located under the organic light emitting layer 142A has a higher ratio of light confined in the ITO mode than the light emitted from the second organic light emitting layer disposed on the upper side. In the organic light emitting diode display 100A according to an embodiment of the present invention, the organic light emitting layer 142A is formed in a structure in which a plurality of organic light emitting layers are stacked to emit white light, Since the organic light emitting layer is an organic light emitting layer that emits blue light, it is possible to reduce the confinement of the blue light emitted from the first organic light emitting layer into the ITO mode. Accordingly, not only the overall light efficiency of the organic light emitting display 100A is improved, but also the light efficiency for blue light, which is a problem in a general organic light emitting display, can be improved.

When a plurality of recesses 161A are formed in the overcoat layer 160A through a process such as photolithography or the like, the overcoat layer 160A is formed with a plurality of concave portions 161A as in the case of the first connection portions 162A shown in FIG. peaky, and morphology are rapidly changing. The organic luminescent layer 142A of the organic luminescent element 140A is formed in such a manner as to deteriorate the step coverage of the organic luminescent layer 142A such as a thermal deposition method, A region where the organic light emitting layer is not formed on the anode may occur, and thus there is a high probability that the anode and the cathode are short-circuited. The organic light emitting diode display 100A according to an exemplary embodiment of the present invention employs the step relaxation layer 170A that alleviates the stepped portion of the overcoat layer 160A by the plurality of recesses 161A, It is possible to greatly reduce the probability that the anode 141A and the cathode 143A are short-circuited.

In the organic light emitting diode display 100A according to an embodiment of the present invention, a step relaxation layer 170A having a refractive index of about 1.7 to 2.0, which is a refractive index larger than that of the overcoat layer 160A, is formed on the overcoat layer 160A do. The light emitted from the organic light emitting layer 142A passes through the anode 141A and the step difference reducing layer 170A because the refractive index of the ITO used as the anode 141A is about 1.7 and the refractive index of the overcoat layer 160A is about 1.5, The total reflection can be achieved at the interface between the step reducing layer 170A and the overcoat layer 160A. The overcoat layer 160A of the OLED display 100A according to an embodiment of the present invention includes a plurality of concave portions 161A and the step difference reducing layer 170A includes a plurality of concave portions 161A Is formed on the overcoat layer 160A, the overcoat layer 160A and the step difference reducing layer 170A can form an MLA structure. Therefore, the incident angle of the light emitted from the organic light emitting layer 142A incident on the interface between the step reducing layer 170A and the overcoat layer 160A is likely to be smaller than the total reflection critical angle. Thus, in the ITO mode, It is possible to reduce the amount of light trapped in the light emitting diode. The light emitted from the organic light emitting layer 142A passes through the interface between the step reducing layer 170A and the overcoat layer 160A and proceeds at an angle close to the vertical direction with respect to the lower surface of the substrate 110A Reference). Therefore, since the light passing through the interface between the step reducing layer 170A and the overcoat layer 160A is likely to be smaller than the total reflection critical angle for the substrate mode, the amount of light confined in the organic light emitting display 100A in the substrate mode . Further, multiple reflections can be performed on the light emitted from the interface between the step reducing layer 170A and the overcoat layer 160A, so that light is recycled to meet the MLA structure of the overcoat layer 160A and the step reducing layer 170A The number of times may be increased. Therefore, the amount of light confined in the organic light emitting display 100A can be reduced by the ITO mode and the substrate mode, so that the light extraction efficiency is increased and the lifetime of the organic light emitting element 140A is also increased.

As described above, in the OLED display 100A according to the embodiment of the present invention, the overcoat layer 160A including the plurality of recesses 161A and the step reducing layer 170A form the MLA structure, This structure is formed between the color filter 150A and the anode 141A. Therefore, compared with the structure in which the MLA structure is disposed outside the substrate 110A, the blurring phenomenon or the ghosting phenomenon can be eliminated in the OLED display 100A according to the embodiment of the present invention, and the overcoat layer 160A And the step difference reducing layer 170A can be prevented from passing through the circular polarizer plate and being canceled out by the light reflected to the inside of the OLED display 100A. The plurality of concave portions 161A of the overcoat layer 160A in the organic light emitting diode display 100A according to the exemplary embodiment of the present invention are formed to overlap with the color filters 150A so that blurring or ghosting Can be removed.

Since the organic light emitting diode display 100A according to one embodiment of the present invention is an organic light emitting diode display of the bottom emission type, the cathode 143A is formed of a metallic material having excellent reflectivity, so that light emitted from the organic light emitting layer 142A Is reflected by the cathode 143A and proceeds toward the substrate 110A side and the cathode 143A of the organic light emitting diode display 100A has unperforated upper and lower surfaces. Concretely, the cathode 143A formed on the concave portion 161A of the overcoat layer 160A among the cathodes 143A has an unperforated upper and lower surfaces to have an aspect ratio of about 0.5 to 0.7.

Accordingly, as the surface shape of the cathode 143A is deformed, the advancing angle of the light emitted from the organic light emitting layer 142A, which is reflected by the cathode 143A and directed toward the anode 141A side, is the overcoat layer 160A and the step relaxation layer 170A (Refer to L2 in Fig. 1B). Therefore, the amount of light confined in the organic light emitting display device 100A can be reduced, so that the voltage and current for emitting the light of the same luminance are reduced, the power is also reduced, and the lifetime of the organic light emitting device 140A is Can be increased.

1A and 1B, only a cross-sectional view and a sectional enlarged view of the organic light emitting diode display 100A are shown, but a plurality of recesses 161A of the overcoat layer 160A of the organic light emitting diode display device 100A are connected to the color filters 150A ) In a hexagonal structure.

1A and 1B, the passivation layer 133A is shown to planarize the upper surface of the thin film transistor 120A. However, the passivation layer 133A does not planarize the upper surface of the thin film transistor 120A, Or may be formed along the shape. 1A and 1B, the passivation layer 133A is included in the organic light emitting diode display 100A, but the passivation layer 133A is not used, and the overcoat layer 133A is formed on the thin film transistor 120A. (160A) may be formed.

1A and 1B, the color filter 150A is formed on the passivation layer 133A. However, the color filter 150A is not limited thereto, and the color filter 150A may include an overcoat layer 160A forming the MLA structure, And may be formed at any position between the lower portion of the layer 170A and the substrate 110A.

The overcoat layer 160A may be formed together with the color filter 150A in the manufacturing process of the organic light emitting diode display device 100A and the overcoat layer 160A may be patterned according to the manufacturing process conditions so that the overcoat layer 160A may include a plurality of concave It may be difficult to have the portion 161A. In this case, a plurality of concave portions 161A are not formed directly on the overcoat layer 160A, but another photoresist is coated on the overcoat layer 160A, another photoresist is patterned, The MLA structure can be formed with the step reducing layer 170A having a plurality of concave portions.

FIG. 1C is an enlarged cross-sectional view illustrating a shape of an overcoat layer and a step relaxation layer different from FIG. 1B of the organic light emitting diode display according to an exemplary embodiment of the present invention. The organic light emitting display 100C of FIG. 1C differs from the organic light emitting display 100A of FIGS. 1A and 1B in the shape of the overcoat layer 160C and the step reducing layer 170C, , So redundant explanations are omitted.

Referring to FIG. 1C, each of the plurality of concave portions 161C of the overcoat layer 160C overlaps with the concave portions 161C adjacent to each other. In FIG. 1C, the portion where the concave portion 161C is overlapped and removed is shown by a dotted line. The diameter 2R of each of the plurality of concave portions 161C of the overcoat layer 160C is equal to or greater than the distance S between the centers of the concave portions 161C adjacent to each other. When the plurality of concave portions 161C are hemispherical, the hemispherical diameter is equal to or larger than the distance S between the centers of the hemispherical shapes adjacent to each other, and when the plurality of concave portions 161C are semi- The semi-ellipsoidal shape has a diameter that is greater than or equal to the distance (S) between the centers of the semi-elliptical shapes adjacent to each other. The diameter 2R of the concave portion 161C means a diameter in a state in which the concave portion 161C is not overlapped with the concave portion 161C adjacent to each other and the center of the concave portion 161C is a radius Shaped or semi-ellipsoidal shape of the concave portion 161C.

When the plurality of concave portions 161C are overlapped with each other, the pitch between the concave portions 161C adjacent to each other is small as compared with the case where the plurality of concave portions 161C are not overlapped. In addition, the smaller the pitch between the plural concave portions 161C, the larger the size of the grating vector. Therefore, in the organic light emitting diode display 100C according to the embodiment of the present invention, the concave portions 161C adjacent to each other are formed to overlap with each other, thereby increasing the size of the grating vector, .

FIG. 1D is an enlarged cross-sectional view illustrating an additional insulating layer of an OLED display according to an exemplary embodiment of the present invention. Referring to FIG. The organic light emitting display 100D of FIG. 1D differs from the organic light emitting display 100A of FIGS. 1A and 1B only in that it further includes an insulating layer 134D, and the other structures are substantially the same, Duplicate descriptions are omitted.

An insulating layer 134D is further formed between the passivation layer 133D and the color filter 150D. The insulating layer 134D has a refractive index smaller than the refractive index of the overcoat layer 160D and the refractive index of the color filter 150D. The insulating layer 134D may be formed of a fluorinated polymer having a refractive index of about 1.3 to 1.4, for example, lithium fluoride (LiF), but is not limited thereto and may be formed of any material having a refractive index of about 1.3 to 1.4 .

The refractive index of the color filter 150D is about 1.5 and the refractive index of the insulating layer 134D formed below the color filter 150D is about 1.3 to 1.4 so that the light emitted from the organic light emitting layer 142D has an incident angle larger than the total reflection critical angle The light incident on the interface between the color filter 150D and the insulating layer 134D is totally reflected at the interface between the color filter 150D and the insulating layer 134D. When the insulating layer 134D is not used, the light emitted from the organic light emitting layer 142D and passing through the color filter 150D has an incident angle larger than the total reflection critical angle in the OLED display 100D according to an embodiment of the present invention. The light totally reflected at the interface between the substrate 110D and air is totally reflected at the interface between the color filter 150D and the insulating layer 134D and proceeds to the MLA structure of the step reducing layer 170D and the overcoat layer 160D , And may be changed to light that travels at an incident angle smaller than the total reflection critical angle at the interface between the substrate 110D and the air by passing the MLA several times. Therefore, in the organic light emitting diode display 100D according to the embodiment of the present invention, by using the insulating layer 134D having a refractive index smaller than that of the overcoat layer 160D and the refractive index of the color filter 150D, It is possible to increase the light extraction efficiency with respect to the light confined in the organic light emitting diode display 100D.

Although the insulating layer 134D is illustrated as being formed on the passivation layer 133D in FIG. 1D, the insulating layer 134D may be formed at another position between the substrate 110D and the color filter 150D.

1D, an insulating layer 134D is shown between the color filter 150D and the passivation layer 133D. However, an air gap may be formed instead of the insulating layer 134D. That is, a space filled with air may be formed between the color filter 150D and the passivation layer 133D. Since the refractive index of air is smaller than the refractive index of the color filter 150D, the air gap 480 can produce the same effect as the above-described insulating layer 134D. The air gap 480 may also be formed at another position between the substrate 110D and the color filter 150D in the same manner as the insulating layer 134D.

1E is a cross-sectional view illustrating an organic light emitting display including an overcoat layer including a plurality of convex portions and a step reducing layer according to an embodiment of the present invention. The organic light emitting diode display 100E of FIG. 1E is different from the organic light emitting display 100A of FIGS. 1A and 1B in that the overcoat layer 160E includes a plurality of protrusions 163E and the step relaxation layer 170E. And the other configurations are substantially the same as each other, so redundant explanations are omitted.

The overcoat layer 160E includes a plurality of convex portions 163E formed to overlap with the color filter 150E and a second connecting portion 164E connecting the convex portions 163E adjacent to each other. The plurality of convex portions 163E are hemispherical or semispherical. Fig. 1E is a cross-sectional view of a portion of the hemispherical shape or semi-ellipsoid shape of the plurality of convex portions 163E having the maximum height, and the plurality of convex portions 163E are shown in a semicircular shape. The diameter and height of the plurality of convex portions 163E may be the same as the diameter 2R and the height D of the concave portions 161A shown in Figs. 1A and 1B.

A step reducing layer 170E is formed on the overcoat layer 160E. The step reducing layer 170E is a layer for alleviating the stepped portion by the plurality of convex portions 163E of the overcoat layer 160E. 1E, the thickness h1 of the step reducing layer 170E formed on the convex portion 163E of the overcoat layer 160E is set so as to be greater than the thickness h1 of the overcoat layer 160E in order to alleviate the stepped portion by the plurality of convex portions 163E. The step reducing layer 170E is formed such that the thickness h2 of the step reducing layer 170E formed on the second connecting portion 164E of the stepped portion 160E is smaller than the thickness h2 of the step reducing layer 170E formed on the second connecting portion 164E.

Referring to FIG. 1E, the step reducing layer 170E is formed so that its top surface is an unplated surface. That is, the upper surface portion of the step reducing layer 170E formed on the convex portion 163E of the overcoat layer 160E and the upper surface portion of the step reducing layer 170E formed on the second connecting portion 164E of the overcoat layer 160E Are on different planes from each other, and the upper surface of the step reducing layer 170E is formed to be an unplated surface.

The overcoat layer 160E has a plurality of protrusions 163E and the step relaxation layer 170E has a plurality of protrusions 16OE of the overcoat layer 160E in the organic light emitting diode display 100E according to an embodiment of the present invention. 163E. The overcoat layer 160E and the step difference reducing layer 170E form an MLA structure and the MLA structure of the overcoat layer 160E and the step difference reducing layer 170E is the same as the overcoat layer 160A described with reference to FIGS. And the MLA structure of the step difference reducing layer 170A. Further, the step difference reducing layer 170E may have the same function as the step difference reducing layer 170A described with reference to Figs. 1A and 1B.

FIG. 2A is a cross-sectional view illustrating an organic light emitting diode display including a plurality of concave portions and a filling layer having a cut-off end according to an exemplary embodiment of the present invention. 2B is an enlarged cross-sectional view of the X region of FIG. 2A. 2A and 2B, the organic light emitting diode display 200 includes a substrate 210, a thin film transistor 220, a color filter 250, an overcoat layer 260, a filling layer 270, 240). The organic light emitting display device 200 of FIGS. 2A and 2B differs from the organic light emitting display device 100A of FIGS. 1A and 1B in that the shape of the overcoat layer 260 is different and the filling layer 270 is employed And the other configurations are substantially the same, so redundant explanations are omitted.

An overcoat layer 260 is formed on the color filter 250 and the passivation layer 233. The overcoat layer 260 includes a plurality of cut-out portions 261 formed to overlap with the color filter 250. Since the concave portion 261 having a plurality of curved bottoms has a hemispherical shape or semi-ellipsoid shape with a hem cut, the side surface of the concave portion 261 having a plurality of cut-off hems is a curved surface, Each of the recesses 261 of the color filter 250 exposes the color filter 250. The overcoat layer 260 functions as a planarization layer in a portion where a plurality of hem-cut recesses 261 are not formed.

A filler layer 270 is formed on the overcoat layer 260. The filling layer 270 is formed of a material having a refractive index larger than the refractive index of the overcoat layer 260. The refractive index of the filling layer 270 may be about 1.7 to 2.0. Specifically, the filling layer 270 may be a layer in which nano particles having a size of several tens of nanometers, such as titanium oxide (TiO2), zirconium oxide (ZrO2), etc., having a refractive index larger than that of the polymer binder are dispersed in the polymeric binder, Nanoparticles such as titanium oxide (TiO2), zirconium oxide (ZrO2), etc. having a refractive index larger than the refractive index are dispersed in the photoresist.

The filling layer 270 fills at least a part of the inside of the concave portion 261 having a cut-off shape of the foot of the overcoat layer 260. The fact that the filling layer 270 fills at least a part of the inside of the cut-out concave portion 261 means that as shown in FIG. 2B, the filling layer 270 has a concave portion 261 having a cut- It is possible to fill only a part of the inside of the concave part 261, or the filling layer 270 may fill all the inside of the recessed part 261 having a cut-off part. 2B, when the depressed portion 261 of the depressed shape of the depressed portion 270 fills only a part of the interior of the depressed portion 261, the depressed portion 261 The filler layer 270 is formed to have an embossed structure by filling only a part of the space of the concave portion 261 cut from the foot.

The overcoat layer 260 of the organic light emitting diode display 200 according to an embodiment of the present invention includes a concave portion 261 having a plurality of cut ends and a plurality of concave portions 261 having a cut- The color filter 250 is exposed. A portion of the filling layer 270 formed on the overcoat layer 260 filling the recessed portion 261 having a plurality of cut ends of the overcoat layer 260 may be in contact with the overcoat layer 260, And contacts the filter 250. When the light emitted from the organic light emitting layer 242 travels to the surface where the filling layer 270 and the overcoat layer 260 are in contact with each other, the interface between the overcoat layer 160A and the step reducing layer 170A described in FIGS. The light emitted from the organic light emitting layer 242 proceeds in the same manner as the progress of the light in the organic light emitting layer 242. On the other hand, when the light emitted from the organic light emitting layer 242 travels on the surface in contact with the filler layer 270 and the color filter 250, since the refractive index of the filler layer 270 is larger than the refractive index of the color filter 250, The light emitted from the organic light emitting layer 242 may be totally reflected on the surface where the filler layer 270 and the color filter 250 are in contact with each other. Accordingly, the light totally reflected on the surface where the filling layer 270 contacts the color filter 250 and travels toward the cathode 243 is reflected by the cathode 243 and travels toward the filling layer 270 again, so that light can be recycled And the light emitted from the organic light emitting layer 242 passes through the MLA structure of the filler layer 270 and the overcoat layer 260 again so that light traveling at an incident angle smaller than the total reflection critical angle at the interface between the substrate 210 and air . ≪ / RTI > Therefore, the light extraction efficiency for the light confined in the organic light emitting display 200 in the substrate mode can be improved.

2A and 2B, the filling layer 270 is formed to have an embossed structure. However, the filling layer 270 may fill all of the inside of the concave portion 261 having a plurality of cut ends, The upper portion of the coating layer 260 may be planarized.

3 is a flowchart illustrating a method of manufacturing an OLED display device including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention. 4A to 4F are cross-sectional views illustrating a method of manufacturing an organic light emitting display including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention. 4A to 4F, a portion corresponding to a thin film transistor among various elements of the organic light emitting display 400 is not shown, and a portion of the organic light emitting display 400, which overlaps the portion where the color filter 450 is formed, Respectively. In addition, the organic light emitting display 400 of FIG. 4F is substantially the same as the organic light emitting display 100A of FIG. 1B.

First, a color filter 450 is formed on a substrate 410 (S30). Reference is made to Fig. 4C for a more detailed description of forming the color filter 450 on the substrate 410. Fig.

Referring to FIG. 4C, a color filter 450 is formed on the substrate 410. More specifically, the color filter 450 is formed on the passivation layer 433 on the substrate 410.

In some embodiments, an air gap 480 may be formed between the substrate 410 and the color filter 450. See also FIGS. 4A and 4B for a more detailed description of forming the air gap 480. FIG.

4A, a sacrificial layer (not shown) is formed between the substrate 410 and the color filter 450, which is thermally decomposed, before the color filter 450 is formed on the substrate 410 to form the air gap 480. [ (481) can be formed. Specifically, a sacrifice layer 481 is formed between the passivation layer 433 and the color filter 450. The sacrificial layer 481 may be formed of various materials that are formed of a material that is decomposed upon heat treatment and which are decomposed and removed by heat.

4A and 4B, after the sacrifice layer 481 is formed, the color filter 450 may be formed on the sacrifice layer 481, and the sacrifice layer 481 may be formed after the color filter 450 is formed. The sacrifice layer 481 can be disassembled to form an air gap 480 between the substrate 410 and the color filter 450. [

Then, an overcoat layer 460 including a plurality of recesses 461 overlapping the color filter 450 is formed on the color filter 450 (S31). Reference is made to Figs. 4C and 4D for a more detailed description of forming an overcoat layer 460 including a plurality of recesses 461. Fig.

Referring to FIG. 4C, a photoresist material 469 is applied over the color filter 450 to form an overcoat layer 460. The photoresist can use both a negative type photoresist and a positive type photoresist. However, in order to form the concave portion 461 in the overcoat layer 460, It is advantageous. A photolithography process is performed on the overcoat layer 460 to form a plurality of recesses 461 of the overcoat layer 460 as shown in FIG. The plurality of recesses 461 may be formed only in the overcoat layer 460 overlapped with the color filter 450.

In some embodiments, the overcoat layer 460 may be formed in the same shape as the overcoat layer 260 shown in FIG. 2A by adjusting the exposure amount and the like in the photolithography process described above. For example, by increasing the amount of exposure, the amount of photoresist material 469 to be patterned can be increased, so that the overcoat layer 460 can be formed by a plurality of concave recesses May be formed to have a portion 261.

4C and 4D illustrate that the overcoat layer 460 is formed of photoresist, but it is not limited thereto. The overcoat layer 460 may be formed of various insulating materials having a refractive index of about 1.5 And the plurality of recesses 461 of the overcoat layer 460 can be formed through a photolithography process for various insulating materials.

4C and 4D, a plurality of concave portions 461 are formed in the overcoat layer 460. However, as shown in FIGS. 2A and 2B, when the overcoat layer 460 is formed of a plurality of convex portions 263, As shown in FIG. A photoresist material 469 may be applied on the color filter 450 as shown in Figure 4C and a photolithography process may be performed to form the plurality of protrusions 263 in the overcoat layer 460 .

In some embodiments, an insulating layer having a refractive index less than the refractive index of the overcoat layer 460 and the refractive index of the color filter layer 450 is provided between the substrate 410 and the color filter 450 before the color filter 450 is formed. . The insulating layer may be formed at the same position as the air gap 480 shown in FIG. 4B.

Subsequently, a step difference reducing layer 470 is formed on the overcoat layer 460 to have a refractive index larger than the refractive index of the overcoat layer 460 and to alleviate the stepped portion 461 (step S32). See FIG. 4E for a more detailed description of forming the step relaxation layer 470. FIG.

Referring to FIG. 4E, a spin coating method may be used to form the step reducing layer 470. That is, forming the step relaxation layer 470 includes spin coating a nanoparticle-dispersed polymer binder or porothegist. During spin coating, the spin coating rate and the viscosity of the polymeric binder or photoresist can be adjusted to control the thickness and unevenness of the step relaxation layer 470. For example, when the spin-coating speed is increased and the viscosity of the polymer binder or photoresist is lowered, the spin-coating speed is lowered and the viscosity of the polymer binder or photoresist is increased compared to the case of increasing the viscosity of the polymer binder or photoresist. The thickness of the step reducing layer 470 may be relatively low, and the non-flatness may be relatively high. The thickness of the step relaxation layer 470 formed on the concave portion 461 of the overcoat layer 460 may be greater than the thickness of the first connection portion 462 of the overcoat layer 460. [ The spin-coating rate or the viscosity of the polymer binder or the photoresist can be adjusted so as to be greater than the thickness of the step reducing layer 470 formed on the substrate.

Although not shown in FIG. 4E, even when the overcoat layer 460 has a plurality of convex portions as shown in FIG. 2, the thickness of the stepped relieving layer 470 formed on the convex portions of the overcoat layer 460 is over The spin coating speed or the viscosity of the polymer binder or the photoresist can be controlled so as to be smaller than the thickness of the step reducing layer 470 formed on the second connecting portion of the coating layer 460.

4E, a spin coating method is used to form the step reducing layer 470. However, the present invention is not limited to the photolithography, the slit coating, the ink jet printing, the dip coating, a variety of wet coating methods such as nozzle printing, screen printing and the like can also be used.

Then, the anode 441, the organic light emitting layer 442, and the cathode 443 are sequentially layered on the step reducing layer 470 to form the organic light emitting device 440 (S33). Reference is made to Fig. 4e for a more detailed description of forming the organic light emitting element 440. Fig.

4E, an anode 441 is formed along the shape of the step reducing layer 470, the organic light emitting layer 442 is formed on the anode 441 along the shape of the anode 441, 442, the cathode 443 is formed along the shape of the organic light emitting layer 442.

Since the organic light emitting display according to the embodiment of the present invention has the same or higher level of light extraction efficiency as compared with Comparative Example 1 by applying the overcoat layer and the step difference reducing layer of the present invention, See Table 1 together for a more detailed description of low current efficiency and power efficiency.

The driving voltage (V) cd / A lm / W Comparative Example 1 12.8 66 16 The organic light emitting display according to the embodiment of the present invention 10.9 93 27

In Table 1, the organic light emitting display according to Comparative Example 1 and one embodiment of the present invention is a white organic light emitting device in which two organic light emitting layers are stacked and designed. At this time, one of the two organic light emitting layers is an organic light emitting layer that emits blue light, and the other is an organic light emitting layer that emits yellow green light. These two organic light emitting layers are laminated.

In Table 1, an OLED display according to an embodiment of the present invention has a structure in which a substrate, an overcoat layer, a step relaxation layer, an anode, an organic light emitting layer, and a cathode are stacked from the bottom. In this case, the organic light emitting layer specifically includes a charge injecting layer or charge transporting layer of 50 nm from the bottom, an organic light emitting layer emitting 20 nm of the yellow green light, a charge injecting or charge transporting layer of 90 nm, A light-emitting layer, and a 180-nm charge injection layer or charge transport layer. At this time, the overcoat layer and the step difference reducing layer mean the overcoat layer and the step difference reducing layer of the present invention. At this time, the charge injection layer or the charge transporting layer may be a hole injection layer, a hole transporting layer, a charge generating layer, an electron injecting layer, an electron transporting layer, or the like.

In Table 1, Comparative Example 1 is the same as the organic light emitting display according to one embodiment of the present invention, except that the overcoat layer and the step relaxation layer of the present invention are not applied. Emitting layer was used. In other words, the OLED display according to an embodiment of the present invention is different from the OLED display in that the overcoat layer and the step difference reducing layer of the present invention are applied.

In Table 1, although the organic light emitting display according to Comparative Example 1 and the organic light emitting display according to an embodiment of the present invention use the organic light emitting layer having the same thickness, the driving voltage V of the organic light emitting display according to the embodiment of the present invention is Which is lower than the drive voltage of Comparative Example 1 by 1.9 V. Thus, the current efficiency (cd / A) and the power efficiency (lm / W) of the organic light emitting diode display according to the embodiment of the present invention were increased by 40% and 65%, respectively,

The organic light emitting display according to an embodiment of the present invention can provide a light extraction efficiency equal to or higher than that of the organic light emitting display of Comparative Example 1, See Table 2 for a more detailed explanation of the fact that it can be reduced.

The driving voltage (V) cd / A lm / W Comparative Example 1 12.8 66 16 The organic light emitting display according to the embodiment of the present invention 7.8 97 39

In Table 2, the organic light emitting display according to Comparative Example 1 and one embodiment of the present invention are all white organic light emitting devices designed by stacking two organic light emitting layers. At this time, one of the two organic light emitting layers is an organic light emitting layer that emits blue light, and the other is an organic light emitting layer that emits yellow green light. These two organic light emitting layers are laminated.

In Table 2, the OLED display according to an embodiment of the present invention has a structure in which a substrate, an overcoat layer, a step relaxation layer, an anode, an organic light emitting layer, and a cathode are stacked from the bottom. Specifically, the organic luminescent layer is composed of a charge injecting / transporting layer of 50 nm from the bottom, an organic luminescent layer emitting 20 nm of sulfur green light, a charge injecting / transporting layer of 70 nm, an organic luminescent layer emitting luminescent blue light of 20 nm, The charge injecting or transporting layer is stacked. At this time, the overcoat layer and the step difference reducing layer mean the overcoat layer and the step difference reducing layer of the present invention. In this case, the charge injecting or transporting layers may be a hole injecting layer, a hole transporting layer, a charge generating layer, an electron injecting layer, an electron transporting layer, or the like.

In Table 2, an organic light emitting display device according to an embodiment of the present invention has an organic light emitting layer emitting blue light, an organic light emitting layer emitting yellow green light, and charge injection or transport layers all having a thickness of less than 100 nm. Alternatively, each of the layers constituting the organic light emitting layer of the organic light emitting display according to an embodiment of the present invention all have a thickness of less than 100 nm.

In Table 2, Comparative Example 1 shows that the overcoat layer and the step difference reducing layer of the present invention are not applied, and the charge transporting layer in the organic light emitting display according to the embodiment of the present invention has a thickness smaller than that of the injection layers, Transport or injection layers. Except for this, the organic light emitting display according to Comparative Example 1 and the OLED display according to an embodiment of the present invention have the same structure.

In Table 2, the driving voltage V of the OLED display device according to an embodiment of the present invention, which is about 36% thinner than the thickness of the organic light emitting layer of Comparative Example 1, is 5 V low. As a result, the current efficiency and the power efficiency of the OLED display according to an embodiment of the present invention were increased by 47% and 140%, respectively, compared with the current efficiency and power efficiency of the first comparative example.

That is, by applying the overcoat layer and the step difference reducing layer of the present invention, the light extraction efficiency can be improved while drastically reducing the thickness of the organic light emitting layer. As a result, it is possible to obtain a better effect in terms of reduction of driving voltage and power consumption, current efficiency and power efficiency.

Hereinafter, various features of the organic light emitting diode display including the overcoat layer and the step reducing layer including a plurality of recesses according to an embodiment of the present invention will be described.

According to another aspect of the present invention, the organic light emitting layer has a thickness of 350 nm or less.

According to another aspect of the present invention, the organic light emitting layer further includes a charge injecting layer or charge transporting layer, and both the charge injecting layer and the charge transporting layer have a thickness of less than 100 nm.

According to another aspect of the present invention, the upper surface of the step reducing layer is an unplasticized surface.

According to still another aspect of the present invention, the overcoat layer includes a first connecting portion connecting each of the recesses or a second connecting portion connecting each of the convex portions.

According to another aspect of the present invention, when the overcoat layer includes the first connecting portion, the thickness of the step reducing layer formed on the concave portion is larger than the thickness of the step reducing layer formed on the first connecting portion.

According to another aspect of the present invention, when the overcoat layer includes the second connecting portion, the thickness of the step reducing layer formed on the convex portion is smaller than the thickness of the step reducing layer formed on the second connecting portion.

According to still another aspect of the present invention, the anode, the organic light emitting layer, and the cathode are formed along the shape of the upper surface of the step reducing layer, and are characterized by unperforated upper and lower surfaces.

According to still another aspect of the present invention, one of the convex portion and the concave portion is in a hemispherical shape or a semi-ellipsoidal shape.

According to still another aspect of the present invention, the aspect ratio of the cathode formed on the convex portion or the concave portion is 0.5 to 0.7.

According to another aspect of the present invention, the hemispherical shape and the semi-ellipsoidal shape each have a diameter of 1 to 5 mu m and a height of 1 to 4 mu m.

According to another aspect of the present invention, the hemispherical diameter is greater than or equal to the distance between the centers of the hemispherical shapes adjacent to each other, and the diameter of the hemispherical shape is greater than or equal to the distance between the centers of the semi- .

According to another aspect of the present invention, an organic light emitting layer is formed by stacking a plurality of organic light emitting layers to emit white light, and a plurality of organic light emitting layers includes a blue organic light emitting layer.

According to still another aspect of the present invention, the refractive index of the step reducing layer is 1.7 to 2.0.

According to another aspect of the present invention, the step reducing layer is a polymer binder or a layer in which a polymer binder and a nanoparticle having a refractive index larger than that of the photoresist are dispersed in a photoresist.

According to another aspect of the present invention, an organic light emitting display further includes an insulating layer formed between the substrate and the color filter, the insulating layer having a refractive index smaller than a refractive index of the overcoat layer and a refractive index of the color filter.

According to another aspect of the present invention, the insulating layer is formed of a fluorinated polymer having a refractive index of 1.3 to 1.4.

According to another aspect of the present invention, an organic light emitting diode display further includes an air gap formed between the substrate and the color filter.

Hereinafter, various features of the organic light emitting diode display including the concave portion and the filling layer having a plurality of cut-off edges according to an embodiment of the present invention will be described.

According to another aspect of the present invention, the filling layer is a layer for planarizing an upper portion of the overcoat layer.

According to another aspect of the present invention, the filling layer is formed so as to have an embossed structure by filling only a part of the space of the concave portion from the bottom of the concave portion.

Hereinafter, various features of an OLED display manufacturing method including an overcoat layer including a plurality of recesses and a step reducing layer according to an embodiment of the present invention will be described.

According to another aspect of the present invention, the step of forming an overcoat layer includes a step of applying a photoresist material on the color filter and a step of forming a plurality of convex portions or a plurality of concave portions of the overcoat layer through a photolithography process .

According to still another aspect of the present invention, the step of forming the step relaxation layer includes spin coating the nanoparticle-dispersed polymer binder or the photoresist.

According to another aspect of the present invention, the step of spin-coating includes the step of adjusting the thickness of the step reducing layer by adjusting the spin-coating speed and the viscosity of the polymer binder or the photoresist.

According to still another aspect of the present invention, the step of forming the organic light emitting element includes the steps of forming an anode along the shape of the step reducing layer, forming an organic light emitting layer along the shape of the anode on the anode, And forming a cathode along the shape of the cathode.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting diode display, the method including forming an insulating layer between a substrate and a color filter, the insulating layer having a refractive index of an overcoat layer and a refractive index smaller than a refractive index of the color filter layer .

According to another aspect of the present invention, a method of manufacturing an organic light emitting display includes forming a sacrificial layer which is thermally decomposed between a substrate and a color filter, and thermally treating the sacrificial layer to form an air gap between the substrate and the color filter And further comprising:

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

110A, 110C, 110D, 110E, 210, 410:
120A, 120C, 120D, 120E, 212, 420: thin film transistors
121A, 121C, 121D, 121E, 221, 421:
122A, 122C, 122D, 122E, 222, 422:
123A, 123C, 123D, 123E, 223, 423:
124A, 124C, 124D, 124E, 224, 424:
131A, 131C, 131D, 131E, 231, 431: gate insulating layer
132A, 132C, 132D, 132E, 232, 432:
133A, 133C, 133D, 133E, 233, 433: passivation layer
134D: Insulating layer
136A, 136C, 136D, 136E, 236, 436:
140A, 140C, 140D, 140E, 240, and 440:
141A, 141C, 141D, 141E, 241, 441:
142A, 142C, 142D, 142E, 242, 442:
143A, 143C, 143D, 143E, 243, 443: cathode
150A, 150C, 150D, 150E, 250, 450: Color filters
160A, 160C, 160D, 160E, 260, 460: Overcoat layer
161A, 161C, 161D, 461:
261: a concave portion having a cut edge
162A, 162C, 162D, and 462:
163E:
164E:
469: Photoresist material
170A, 170C, 170D, 170E, 470:
270: filling layer
480: air gap
481: sacrificial layer
100A, 100C, 100D, 100E, 200, 400: organic light emitting display

Claims (28)

Board;
A color filter formed on the substrate;
An overcoat layer formed on the color filter and including a plurality of convex portions or a plurality of concave portions formed to overlap the color filter;
A step relaxation layer formed on the overcoat layer and having a refractive index larger than that of the overcoat layer and for alleviating the stepped portion by the convex portion or the concave portion; And
And an organic light emitting diode formed on the step reducing layer and including an anode, an organic light emitting layer formed on the anode, and a cathode formed on the organic light emitting layer. The method according to claim 1,
Wherein the organic light emitting layer has a thickness of 350 nm or less. The method according to claim 1,
The organic light emitting layer may further include a charge injecting layer or charge transporting layer,
Wherein the charge injecting layer and the charge transporting layer all have a thickness of less than 100 nm. The method according to claim 1,
Wherein an upper surface of the step reducing layer is an unplated surface. 5. The method of claim 4,
Wherein the overcoat layer includes a first connection portion connecting the recesses or a second connection portion connecting each of the protrusions. 6. The method of claim 5,
Wherein the thickness of the step reducing layer formed on the concave portion is greater than the thickness of the step reducing layer formed on the first connecting portion when the overcoat layer includes the first connecting portion. . 6. The method of claim 5,
Wherein the thickness of the step reducing layer formed on the convex portion is smaller than the thickness of the step reducing layer formed on the second connecting portion when the overcoat layer includes the second connecting portion. . 5. The method of claim 4,
Wherein the anode, the organic light emitting layer, and the cathode are formed along the shape of the upper surface of the step reducing layer, and have unperforated upper and lower surfaces. The method according to claim 1,
Wherein one of the convex portion and the concave portion has a hemispherical shape or a semi-ellipsoidal shape. 10. The method of claim 9,
Wherein an aspect ratio of the cathode formed on the convex portion or the concave portion is 0.5 to 0.7. 10. The method of claim 9,
Wherein the hemispherical shape and the semi-ellipsoidal shape each have a diameter of 1 to 5 占 퐉 and a height of 1 to 4 占 퐉. 10. The method of claim 9,
The diameter of the hemispherical shape being greater than or equal to the distance between the centers of the hemispherical shapes adjacent to each other,
Wherein a diameter of the semi-elliptical shape is greater than or equal to a distance between centers of the semi-elliptical shapes adjacent to each other. The method according to claim 1,
The organic light emitting layer may have a structure in which a plurality of organic light emitting layers are stacked to emit white light,
Wherein the plurality of organic light emitting layers comprise a blue organic light emitting layer. The method according to claim 1,
And the refractive index of the step reducing layer is 1.7 to 2.0. The method according to claim 1,
Wherein the step reducing layer is a polymer binder or a layer in which nanoparticles having a refractive index larger than the refractive index of the polymeric binder and the photoresist are dispersed in a polymeric binder or a photoresist. The method according to claim 1,
Further comprising an insulating layer formed between the substrate and the color filter and having an index of refraction smaller than a refractive index of the overcoat layer and a refractive index of the color filter. 17. The method of claim 16,
Wherein the insulating layer is formed of a fluorinated polymer having a refractive index of 1.3 to 1.4. The method according to claim 1,
Further comprising an air gap formed between the substrate and the color filter. Board;
A color filter formed on the substrate;
An overcoat layer formed on the color filter, the overcoat layer being formed to overlap with the color filter, the overcoat layer including a plurality of cut-out portions of the hem that expose the color filter; And
And a filling layer formed on the overcoat layer and having a refractive index larger than that of the overcoat layer and filling at least a part of the inside of the concavity,
And an organic light emitting device formed on the filling layer, the organic light emitting device including an anode, an organic light emitting layer formed on the anode, and a cathode formed on the organic light emitting layer,
And the side surface of the concave portion is a sloped curved surface. 20. The method of claim 19,
Wherein the filling layer is a layer for planarizing an upper portion of the overcoat layer. 20. The method of claim 19,
Wherein the filling layer is formed to fill only a part of the space of the concave portion from the bottom of the concave portion to have an embossing structure. Forming a color filter on the substrate;
Forming an overcoat layer on the color filter, the overcoat layer including a plurality of convex portions or a plurality of concave portions overlapping the color filter;
Forming a stepped relaxed layer having a refractive index larger than that of the overcoat layer on the overcoat layer and for alleviating the stepped portion by the convex portion or the concave portion; And
And laminating an anode, an organic light emitting layer and a cathode sequentially on the step reducing layer to form an organic light emitting device. 23. The method of claim 22,
Wherein forming the overcoat layer comprises:
Applying a photoresist material on the color filter; And
And forming the plurality of convex portions or the plurality of concave portions of the overcoat layer through a photolithography process. 23. The method of claim 22,
Wherein the step of forming the step relaxation layer comprises spin coating a polymer binder or photoresist with nanoparticles dispersed therein. 25. The method of claim 24,
Wherein the step of spin coating comprises adjusting a thickness of the step reducing layer by adjusting a spin coating rate and a viscosity of the polymer binder or the photoresist. 23. The method of claim 22,
The forming of the organic light-
Forming the anode along the shape of the stepped relaxed layer;
Forming the organic light emitting layer on the anode along the shape of the anode; And
And forming the cathode along the shape of the organic light emitting layer on the organic light emitting layer. 23. The method of claim 22,
Further comprising the step of forming an insulating layer between the substrate and the color filter, the insulating layer having a refractive index smaller than that of the color filter layer and a refractive index of the overcoat layer. 23. The method of claim 22,
Forming a sacrificial layer which is thermally decomposed between the substrate and the color filter; And
And forming an air gap between the substrate and the color filter by heat treating the sacrificial layer.

Images