KR101552986B1 - Organic Light Emitting Display Device and Method for fabricating the same - Google Patents

Abstract

The present invention relates to an organic electroluminescent display device capable of preventing a dark spot and unevenness and improving image quality characteristics of a display screen, and a method of manufacturing the same, wherein the organic electroluminescent display device includes a non-display area, A spacer formed on the display area of the lower plate, and an upper plate joined to the lower plate as a substance formed in the non-display area, wherein a height of the spacer of the center part is larger than a height of the spacer of the edge part Is higher than the height.

OLED, dark spot, stain, spacer, buffer

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device,

The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly to an organic light emitting display device and a method of manufacturing the same, which can prevent defects such as dark spot and unevenness of an organic light emitting display device, .

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. In recent years, along with the development of an information society, various types of display apparatuses have been increasingly demanded, and various kinds of displays such as a liquid crystal display (LCD), a plasma display panel (PDP), an electro luminescent display (ELD) Research on devices is actively under way. Among them, an organic light emitting display device for displaying an image by controlling the amount of emitted light of an organic light emitting layer by a flat panel display device which can reduce weight and volume, which is a disadvantage of a cathode ray tube (CRT)

Organic electroluminescent display devices are self-luminous elements using a thin light emitting layer between electrodes and have the advantage of thinning like paper. In an active matrix organic electroluminescence display device (AMOLED), pixels composed of three color (R, G, B) sub-pixels are arranged in a matrix form to display an image. Each sub-pixel includes an organic electroluminescent element and a cell driver for independently driving the organic electroluminescent element. The cell driver includes at least two thin film transistors and a storage capacitor and controls the amount of current supplied to the organic light emitting display according to the data signal to control the brightness of the organic light emitting display.

In the structure of a general organic light emitting display device, the upper and lower plates are bonded together by a sealant formed on the edge. At this time, the sealant is formed at a predetermined height so that the gap between the upper plate and the lower plate is maintained. However, since there is a limit in the interval that can be maintained by the sealant, the phenomenon that the upper plate is bent in the lower plate direction occurs as shown in Figs. 1A and 1B.

Particularly, when there is an external impact or when the size of the substrate is increased and the upper plate and the lower plate are used in different types, the substrate is more likely to bend. In this case, the upper plate is brought into contact with the layers formed on the lower plate, the second electrode and the organic light emitting layer are damaged, and a bundle of dark spots and unevenness are generated. In addition, a newton's ring phenomenon occurs due to an external impact and pressing, which deteriorates the image quality of the display screen, thereby deteriorating the reliability of the organic light emitting display.

It is an object of the present invention to provide an organic light emitting display device and a method of manufacturing the same, which can prevent a dark spot and unevenness and improve a picture quality of a display screen.

An organic light emitting display according to an embodiment of the present invention includes a bottom plate defined as a display region including a non-display region, an edge portion and a center portion; a spacer formed on the display region of the bottom plate; Wherein the height of the spacer of the center portion is higher than the height of the spacer of the edge portion.

Here, the edge portion is an area corresponding to a length of 0.05 times the entire display area in the direction from the boundary between the display area and the non-display area toward the center part, and the center part is a region corresponding to the edge part 0.05 times the length of the entire display area, which is a region corresponding to 0.9 times the length of the entire display area.

The spacer is formed of a polyacrylic, polyimide, or rubber resin.

The organic light emitting display includes a cell driving array formed on the display region of the lower plate, a first electrode formed on the cell driving array and electrically connected to the cell driving array, And a bank insulating layer disposed between the first electrode and the second electrode and separating the organic light emitting layer in units of subpixels, wherein the spacer is disposed between the upper surface of the bank insulating layer And the spacer is formed in the form of a dot, a barrier, a bar, or a stripe.

The height of the spacer of the center portion is higher than the height of the spacer of the boundary portion, and the height of the spacer portion of the boundary portion is larger than the height of the spacer portion of the boundary portion. [0031] According to another aspect of the present invention, The height of the spacer is higher than the height of the spacer of the edge portion.

Here, the height of the spacer at the boundary portion gradually increases.

A method of manufacturing an organic light emitting display according to an embodiment of the present invention includes the steps of preparing a bottom plate defined as a display region including a non-display region, an edge portion and a center portion; Forming a spacer in the center portion so that the height of the spacer is higher than the height of the spacer in the edge portion and forming a seal in the non-display region to bond the bottom plate and the top plate do.

Here, the step of forming the spacer may be performed using two masks or a halftone mask.

In the method of manufacturing an organic light emitting display according to another embodiment of the present invention, the display region further includes a boundary portion between the edge portion and the center portion, and the height of the spacer at the center portion is larger than the height of the spacer And the height of the spacer at the boundary portion is higher than the height of the spacer at the edge portion.

Here, the step of forming the spacers is a step of forming using a halftone mask or a multi-tone mask.

The height of the spacer of the center portion is made higher than the height of the spacer of the edge portion of the substrate or the height of the spacer at the boundary portion between the edge portion and the center portion is gradually increased, Can be prevented.

In addition, it is possible to improve the reliability of the organic light emitting display by improving the image quality of the display screen, such as preventing the occurrence of dark spot and unevenness of the large area organic light emitting display device.

Hereinafter, an organic light emitting display device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view schematically illustrating an organic light emitting display according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating a sub-pixel of the organic light emitting display shown in FIG.

The organic light emitting display according to the first embodiment of the present invention includes a cell driving array 120 formed on a display area A of a lower plate 110 defined by a display area A and a non-display area B, An organic electroluminescent device array 130 and a plurality of spacers 170 and a top plate 150 bonded to the bottom plate 110 by a substance 152. The OLED display according to the first embodiment may include a capping layer (not shown) for protecting the structure between the lower plate 110 and the upper plate 150 and a moisture absorbent such as a getter for absorbing moisture, ).

The cell driving array 120 formed in the display area A of the lower substrate 110 is composed of a plurality of sub pixel driving parts, one sub pixel driving part includes a plurality of signal lines, a transistor, a capacitor, and a plurality of insulating films, The transistor includes a switching transistor and a driving transistor.

The switching transistor supplies the data signal from the data line in response to the scanning signal of the gate line. The driving transistor 122 shown in FIG. 3 supplies the data signal to the organic light emitting element array 130). The capacitor serves to allow a constant current to flow through the driving transistor 122 even if the switching transistor is turned off.

The driving transistor 122 includes a gate electrode, a semiconductor layer overlapping the gate electrode with a gate insulating film therebetween, and a source / drain electrode using the semiconductor layer as a channel. Each driving transistor 122 is electrically connected to the organic electroluminescent element through the contact hole of the protective film 124 formed on the driving transistor 122.

The organic electroluminescent device array 130 includes a plurality of organic electroluminescent devices, and the organic electroluminescent device emits red, green, and blue light according to the current flow to display predetermined image information. The organic electroluminescent device includes a first electrode 132 connected to the driving transistor 122, a second electrode 136 serving as an opposite electrode, and an organic light emitting layer 134 disposed between and emitting light. The first electrode 132 and the second electrode 136 are insulated from each other and a voltage of different polarity is applied to the organic light emitting layer 134 to emit light.

The first electrode 132 is used as an anode electrode and is formed on the protective film 124 to be electrically connected to the drain electrode of the driving transistor 122 through a contact hole formed in the protective film 124. At this time, the first electrode 132 is formed so as not to be connected to the first electrode 132 of the adjacent sub-pixel by a predetermined distance from the boundary of the sub-pixel.

When the organic electroluminescent display device is designed as a backlight, the first electrode 132 is formed of a transparent conductive layer. As the transparent conductive layer, indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO) . The first electrode 132 may be formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag, or the like, and may be formed in a multilayer structure.

The organic light emitting layer 134 is a layer in which light is emitted as the exciton formed by the combination of the holes and electrons injected from the first electrode 132 and the second electrode 136 drops to the ground state, (Not shown). The organic light emitting layer 134 may include a hole injecting layer (HIL), a hole transporting layer (HTL), an emission layer (EML), an electron transporting layer (ETL) electron injection layer (EIL). At this time, the organic light emitting layer 134 is divided into sub-pixel units by the bank insulating layer 138, and emits red, green, and blue light in sub-pixel units.

The second electrode 136 is used as a cathode electrode and is formed entirely on the display area A of the lower plate 110. The second electrode 136 may be formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag, or the like, and may be formed in a multilayer structure.

When the organic electroluminescent display device is designed as a front emission type, the second electrode 136 is formed of a transparent conductive layer so that the work function is high and light emitted from the organic emission layer 134 can be emitted outside the device. As the transparent conductive layer, indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO) .

The organic electroluminescent device thus formed can be divided into sub-pixel units by the bank insulating layer 138 to display an image. The bank insulating layer 138 serves to isolate the second electrode 136 of the organic electroluminescent device and other wirings or devices formed therebelow from interfering with each other. The bank insulating layer 138 is formed on the non-emission region of the lower plate 110 so as to cover the first electrode 132 on the driver transistor 122 and to expose the first electrode 132 in the emission region . As the material of the bank insulating layer 138, an organic material or an inorganic material may be used.

A spacer 170 is formed on the bank insulating layer 138 to prevent the top plate 150 from being pressed. The spacer 170 has a predetermined thickness such that a predetermined gap is maintained between the lower plate 110 and the upper plate 150. The height of the spacer 170 of the center portion is higher than the height of the spacer 170 of the edge portion. At this time, the difference in height between the spacer 170 at the edge portion and the spacer 170 at the center portion is set to 10 μm or less.

4, the edge portion is formed in the display area A (the display area A) and the display area B (the boundary between the display area A and the non-display area B) in the lower plate 110 defined by the non- 0.0 > A < / RTI > in the transverse center direction. When the vertical length of the display area A is D, the distance from the boundary between the display area A and the non-display area B is 0.05D in the vertical center direction. The center portion is 0.9 A of the center width and 0.9 D of the vertical length D, which is an area obtained by subtracting both edge portions from the entire display area A.

When the height of the spacer 170 is made uniform as a whole, a Newton ring phenomenon occurs from the center portion due to an external pressure such as a push test. However, when the height of the spacer 170 of the center portion is made higher than the height of the spacer 170 of the edge portion as in the present invention, occurrence of Newton ring phenomenon can be prevented. In addition, damage of the organic electroluminescent device due to pressing can be prevented, and the image quality of the display screen can be improved, for example, the occurrence of dark spots and unevenness of the organic electroluminescent display device can be improved.

As the material of the spacer 170, polyacryl (PA), polyimide (PI), or rubber resin may be used. When an inorganic insulating material is used as the spacer material, there is a limit to increase the height of the spacer due to the nature of the inorganic insulating material. Therefore, one of the above-mentioned materials is used as the material of the spacer in the present invention.

The spacer 170 may be formed in a dot shape between R, G, and B sub-pixels defined by the emission color of the organic light emitting layer 134 as shown in FIG. 5A. In addition, the spacer 170 may be formed in a barrier shape surrounding the sub-pixel as shown in FIG. 5B. In addition, the spacer 170 may be formed in a bar shape or a stripe shape across R, G, and B pixels as shown in FIG. 5C. The intervals of the spacers 170 may be formed to be one per sub-pixel or one per two sub-pixels, but they may be designed according to the entire panel area.

FIG. 6 is a cross-sectional view schematically showing an organic light emitting display according to a second embodiment of the present invention, and FIG. 7 is a cross-sectional view illustrating a sub-pixel of the organic light emitting display shown in FIG. The upper plate 250 attached to the lower plate 210 by the cell driving array 220, the organic electroluminescence element array 230 and the substance 252 excluding the spacer 270 in the second embodiment is the same as that of the first embodiment The description thereof will be omitted.

The spacer 270 according to the second embodiment has a predetermined thickness such that a predetermined gap is maintained between the lower plate 210 and the upper plate 250. The height of the spacer 270 of the center portion is set to be equal to the height of the spacer 27 And the height of the spacer 270 at the boundary portion is formed to be higher than the height of the edge portion. At this time, the spacer 270 at the boundary portion is formed to be gradually higher from the edge portion toward the center portion. Here, the boundary portion is defined as a boundary region between the edge portion and the center portion.

As the material of the spacer 270, polyacryl (PA), polyimide (PI), or rubber resin may be used. When the inorganic insulating material is used as the spacer material, the height of the spacer is limited due to the nature of the inorganic insulating material. Therefore, the material of the spacer 270 in the present invention is not limited to the polyacrylic (PA), polyimide Select one of the rubber resins.

The spacer 270 may be formed in a dot shape between sub-pixels, a barrier shape surrounding a sub-pixel, or a bar or a stripe across the pixel. The intervals of the spacers 270 may be formed to be one per sub-pixel or one per two sub-pixels, but may be designed according to the entire panel area.

As described above, according to the present invention, the height of the spacer 270 at the boundary portion is gradually increased, thereby preventing the spacer from being damaged by the external pressure due to the abruptly increasing step, and further improving the ability to support the top plate 250. In the present invention, the height of the spacer 270 of the center portion is set to be higher than the height of the spacer 270 at the boundary portion and higher than the height of the spacer 270 at the edge portion than the height of the spacer 270 at the boundary portion, It is possible to prevent the Newton ring phenomenon from occurring in the center portion of the display device. In addition, damage of the organic electroluminescent device due to pressing can be prevented, and the image quality of the display screen can be improved, for example, the occurrence of dark spots and unevenness of the organic electroluminescent display device can be improved.

Specifically, as shown in FIG. 8A, the number of defects generated per substrate was 8.7 in the prior art, but when the spacer structure according to the present invention was formed, the number of defects generated per substrate was 5.4. As described above, the present invention reduces the number of defects generated per substrate by 31% as compared with the prior art. In addition, as shown in FIG. 8B, the defective rate according to the dark spot was 16.7% in the prior art, but when the spacer structure was formed as in the present invention, the defect rate according to the dark spot was 7.4%. As described above, it can be seen that the present invention improves the defect rate by 55.7% in comparison with the conventional art.

Hereinafter, a method of manufacturing the organic light emitting display according to the first and second embodiments will be described with reference to FIGS. 9A to 9C and FIGS. 10A to 10C.

(Embodiment 1)

9A, a driver transistor 122 formed on a sub-pixel unit basis, a planarization film 124 covering the driver transistor 122, and a driver transistor 122 through the planarization film 124 are formed. A lower plate 110 having an electrically connected first electrode 132 and a bank insulating layer 138 exposing a predetermined region of the first electrode 132 is prepared. At this time, the lower plate 110 is defined as a non-display area, a display area including an edge part and a center part, and each edge part and center part are defined as a light emitting area and a non-light emitting area.

The driving transistor 122 is formed in the non-emission region of the lower substrate 110 in units of sub-pixels. Although not shown, on the substrate 110, a switching transistor serving as a switch in addition to the driving transistor 120, a plurality of wirings (not shown) for supplying power and a driving signal to the element, A storage capacitor (not shown) may be further formed to serve to allow a constant current to flow therethrough.

The first electrode 132 formed on the planarization layer 124 to be electrically connected to the drain electrode of the driving transistor 122 may be formed of a material such as Cr, Al, AlNd, Mo, Cu, W, Au, And may be formed of an alloy or oxide thereof or a multilayer of ITO / reflective film / ITO.

The bank insulating layer 138 separates the organic electroluminescent elements by sub-pixel units. The bank insulating layer 138 is formed in the non-emission region of the lower substrate 110 on which the driving transistor 122 is formed, 132 are exposed.

Referring to FIG. 9B, a spacer 170 is formed on the bank insulating layer 138 to prevent the top plate from being pressed.

Specifically, an insulating material is deposited on the entire surface of the lower plate 110 including the bank insulating layer 138 by an evaporation method. As the insulating material constituting the spacer 170, polyacryl (PA), polyimide (PI), or rubber resin is used. When an inorganic insulating material such as a silicon nitride film or a silicon oxide film is used as the spacer material, the height of the spacer is limited due to the nature of the inorganic insulating material. However, in the present invention, by using one of the above-mentioned polyacrylic (PA), polyimide (PI), or rubber resin rather than an inorganic insulating material as a material of the spacer 170, It is easy to raise the height to the design.

Subsequently, the insulating material is selectively patterned using a masking two-step patterning process or a halftone mask 180 in which a blocking region 180a, a semi-transmission region 180b and a transmission region 180c are designed at predetermined positions. Remove. At this time, the halftone mask 180 is aligned so that the blocking region 180a corresponds to the center portion, the semi-transmissive region 180b corresponds to the edge portion, and the transmissive region 180c corresponds to the entire region where no spacer is formed.

Next, a development process is performed to expose the entire surface of the lower plate 110 on which the halftone mask 180 is arranged by irradiating light such as ultraviolet rays, and then removing an insulating material in a region where the characteristics are changed by an exposure process . At this time, the insulating material corresponding to the transmissive region 180c is completely removed to expose a predetermined region of the first electrode 132 and the bank insulating layer 138. The insulating material on the bank insulating layer 138 immediately below the semi-transmissive region 180b is removed to a certain depth to form the bank insulating layer 138 in the center portion, which has the first height and is directly under the blocking region 180a. Lt; / RTI > has a second height. At this time, the spacer 170 of the center portion is formed to be higher than the spacer 170 of the edge portion so that the second height is higher than the first height.

The spacer 170 may be formed in a dot shape between the sub-pixels, a barrier shape surrounding the sub-pixel, or a bar or a stripe across the pixel. The intervals of the spacers 170 may be formed to be one per sub-pixel or one per two sub-pixels, but they may be designed according to the entire panel area.

When the height of the spacer 170 is made uniform as a whole, a Newton ring phenomenon occurs from the center portion due to an external pressure such as a push test. However, when the height of the spacer 170 of the center portion is made higher than the height of the spacer 170 of the edge portion as in the present invention, occurrence of Newton ring phenomenon can be prevented. In addition, damage of the organic electroluminescent device due to pressing can be prevented, and the image quality of the display screen can be improved, for example, the occurrence of dark spots and unevenness of the organic electroluminescent display device can be improved.

9C, after the organic light emitting layer 134 is formed in the light emitting region, the second electrode 136 is sequentially formed on the entire surface of the light emitting region and the non-emitting region, (150).

Specifically, an organic light emitting layer 134 is formed on the first electrode 132 exposed by the sidewalls of the bank insulating layer 138 and the bank insulating layer 138 through an evaporation method such as thermal evaporation . The organic light emitting layer 134 may include a hole injection layer (HIL), a hole transporting layer (HTL), a light emitting layer (EL), an electron transporting layer (ETL) electron injection layer (EIL). Here, the organic light emitting layer 134 is divided into sub-pixel units by the bank insulating layer 138, and is formed to emit red, green, and blue light in units of sub-pixels.

Next, a transparent conductive layer is deposited on the organic light emitting layer 134, and then a second electrode 136 is formed through a photolithography process and an etching process using a mask. (ITO), a tin oxide (TO), an indium zinc oxide (IZO), an indium tin zinc oxide (ITZO), or a transparent conductive layer of indium tin oxide Combinations are used.

Next, after the base material 152 is applied to the non-display area of the lower substrate 110, the lower substrate 110 and the upper substrate 150 are bonded together to complete the organic light emitting display device according to the first embodiment. The organic light emitting display device according to the first embodiment includes a capping layer (not shown) for protecting the structure between the lower plate 110 and the upper plate 150 and a moisture absorbent such as a getter for absorbing moisture, Not shown) can be further formed.

(Second Embodiment)

The manufacturing method of the organic light emitting display according to the second embodiment is the same as that of the first embodiment except for the step of forming the spacer, so the description of the step of forming the same structure will be omitted hereafter.

10A, a driving transistor 222 formed on a sub-pixel unit basis, a planarization film 224 covering the driving transistor 222, and a driving transistor 222 through the planarization film 224 A lower plate 210 having an electrically connected first electrode 232 and a bank insulating layer 238 exposing a predetermined region of the first electrode 232 is prepared. At this time, the lower plate 210 is defined as a display area including a non-display area, an edge part, a boundary part and a center part, and each edge part, boundary part and center part are defined as a light emitting area and a non-light emitting area.

Referring to FIG. 10B, a spacer 270 is formed on the bank insulating layer 238 to prevent the top plate from being pressed.

Specifically, insulating material is deposited on the entire surface of the lower plate 210 including the bank insulating layer 238 by a deposition method. As the insulating material constituting the spacer 270, polyacryl (PA), polyimide (PI), or rubber resin is used. When an inorganic insulating material such as a silicon nitride film or a silicon oxide film is used as the spacer material, the height of the spacer is limited due to the nature of the inorganic insulating material. However, in the present invention, it is easy to increase the height of the spacer 270 to the design value by selecting one of the above-described materials other than the inorganic insulating material as the material of the spacer 270.

Subsequently, a multi-tone mask 280 in which a transmissive area 280a, a first transflective area 280b, a second transflective area 280c, and a blocking area 280d are designed at a predetermined position, Thereby selectively removing the insulating material. At this time, the blocking region 280d is located at the center, the second semi-transmissive region 280c is at the boundary, the first transflective region 280b is at the edge, and the transmissive region 280a is the entire region where no spacer is formed Align the multi-tone mask 280 to correspond.

Then, a light process such as ultraviolet light is irradiated to the entire surface of the lower plate 210 on which the multitone mask 280 is arranged, and a developing process is performed to remove the insulating material in the changed region by the exposure process . At this time, the insulating material corresponding to the transmissive region 280a is completely removed to expose a predetermined region of the first electrode 232 and the bank insulating layer 238. [ The insulating material on the bank insulating layer 238 at the edge portion immediately below the first semi-transmissive region 280b is removed to a certain depth to have a first height, and a portion of the boundary portion directly below the second semi-transmissive region 280c The insulating material on the bank insulating layer 238 is removed to a certain depth to have a second height and the insulating material on the bank insulating layer 238 in the center portion just under the blocking region 280c has the third height.

At this time, the spacer 270 at the boundary portion is higher than the spacer 270 at the edge portion so that the second height is higher than the first height and the third height is higher than the second height, And the negative spacer 270 is formed to be higher. The spacers 270 in the boundary may be all formed to have the same height or may have a height gradually increasing from the edge toward the center.

The spacer 270 may be formed in a dot shape between sub-pixels, a barrier shape surrounding a sub-pixel, or a bar or a stripe across the pixel. The intervals of the spacers 270 may be formed to be one per sub-pixel or one per two sub-pixels, but may be designed according to the entire panel area.

As described above, according to the present invention, the height of the spacer 270 at the boundary portion is gradually increased, thereby preventing the spacer from being damaged by external pressure and improving the ability to support the top plate. In the present invention, the height of the spacer 270 of the center portion is set to be higher than the height of the spacer 270 at the boundary portion and higher than the height of the spacer 270 at the edge portion than the height of the spacer 270 at the boundary portion, It is possible to prevent the Newton ring phenomenon from occurring in the center portion of the display device. In addition, damage of the organic electroluminescent device due to pressing can be prevented, and the image quality of the display screen can be improved, for example, the occurrence of dark spots and unevenness of the organic electroluminescent display device can be improved.

Referring to FIG. 10C, after the organic light emitting layer 234 is formed in the light emitting region, a second electrode 236 is sequentially formed on the entire surface of the light emitting region and the non-emitting region. Next, the EL material 252 is applied to the non-display area of the lower substrate 210, and the lower substrate 210 and the upper substrate 250 are bonded together to complete the organic light emitting display according to the second embodiment. The organic light emitting display device according to the second embodiment includes a capping layer (not shown) for protecting the structure between the lower plate 210 and the upper plate 250 and a moisture absorbent such as getter Not shown) can be further formed.

The above-described techniques represent presently preferred embodiments, and the present invention is not limited to the above-described embodiments and the accompanying drawings. Modifications and other uses of the embodiments will be apparent to those skilled in the art, and such modifications and other uses are intended to be included within the spirit of the present invention or defined by the scope of the appended claims.

FIGS. 1A and 1B are views showing a phenomenon in which a top plate of an organic light emitting display according to the related art is bent.

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

3 is a cross-sectional view illustrating a sub-pixel of the organic light emitting display shown in FIG.

4 is a view showing a region where a spacer of the organic light emitting display device according to the present invention is formed.

5A to 5C are views showing the shape of a spacer of an organic light emitting display device according to the present invention.

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

7 is a cross-sectional view illustrating a sub-pixel of the organic light emitting display shown in FIG.

8A and 8B are comparative graphs showing the number of defects and the defective ratio in forming the spacer structure according to the prior art and the present invention.

9A to 9C are cross-sectional views illustrating a method of fabricating an organic light emitting display according to the first embodiment shown in FIG.

10A to 10C are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a second embodiment shown in FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

110, 210: lower plate 122, 222: driving transistor

124, 224: protective film 132, 232: first electrode

134 and 234: organic light emitting layers 136 and 236:

138, 238: bank insulating layer 170, 270: spacer

180: Halftone mask 280: Multi-tone mask

Claims (10)

A lower plate defined by a non-display area, a display area including an edge part and a center part; A spacer positioned on the display area including the edge portion and the center portion; And And an upper plate joined to the lower plate by a substance formed in the non-display area, Wherein a height of the spacer of the center portion is higher than a height of the spacer of the edge portion. 2. The display device according to claim 1, wherein the edge portion is a region corresponding to a length of 0.05 times the entire display region from the boundary between the display region and the non-display region toward the center portion, Wherein the center portion is an area obtained by subtracting the 0.05-fold length corresponding to the edge portion from the entire display region, and is a region corresponding to 0.9 times the length of the entire display region. The organic electroluminescent display device according to claim 1, wherein the spacer is made of polyacrylic, polyimide, or rubber resin. The display device according to claim 1, further comprising: a cell drive array positioned on the display area of the lower plate; A first electrode located on the cell drive array and electrically connected to the cell drive array; A second electrode which is an opposite electrode of the first electrode, An organic light emitting layer disposed between the first electrode and the second electrode and emitting light; Further comprising a bank insulating layer for separating the organic light emitting layer into sub-pixel units, Wherein the spacer is located on the upper surface of the bank insulating layer, Wherein the spacer is in the form of a dot, a barrier, a bar, or a stripe. The apparatus according to claim 1, further comprising a boundary portion between the edge portion and the center portion, Wherein a height of the spacer of the center portion is higher than a height of the spacer at the boundary portion and a height of the spacer at the boundary portion is higher than a height of the spacer of the edge portion. 6. The organic light emitting display according to claim 5, wherein a height of the spacer at the boundary portion gradually increases. Preparing a lower plate defined by a non-display region, a display region including an edge portion and a center portion; Forming a spacer on the edge portion and the lower plate of the center portion, wherein the height of the spacer of the center portion is higher than the height of the spacer of the edge portion; And Forming a non-display region in the non-display region, and bonding the lower plate and the upper plate to each other. [8] The method of claim 7, wherein the forming of the spacers is performed using two masks or a halftone mask. The display device according to claim 7, wherein the display area further comprises a boundary part between the edge part and the center part, Wherein a height of the spacer in the center portion is higher than a height of the spacer in the boundary portion and a height of the spacer in the boundary portion is higher than a height of the spacer in the edge portion. 10. The method of claim 9, wherein the forming of the spacers is performed using a halftone mask or a multi-tone mask.

Images