KR102532101B1 - Organic light emitting display device and manufacturing method for the same - Google Patents

Abstract

According to the present embodiment, a first substrate, a bank in which a pixel region is defined on the first substrate and a space having a height longer than the width in the first direction is disposed therein, an anode electrode disposed in the pixel region, and a bank an organic film disposed in a pixel region defined by; and a cathode electrode disposed on the organic layer and an encap for flattening the upper portion of the first substrate, but the space is filled with a medium smaller than that of the bank, and a manufacturing method thereof.
According to the present embodiments, an organic light emitting display device capable of increasing light efficiency and a manufacturing method thereof are provided.

Description

Organic light emitting display device and manufacturing method thereof

The present embodiments relate to an organic light emitting display device and a manufacturing method thereof.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and liquid crystal display devices (LCD: Liquid Crystal Display Device), plasma display devices, organic light emitting display devices ( Various types of display devices such as organic light emitting display devices (OLEDs) are being utilized.

Among the above display devices, an organic light emitting display device having a good viewing angle, response characteristics, and power consumption is gradually being used. In particular, mobile devices such as smart phones and tablet PCs are gradually adopting organic light emitting display devices to reduce power consumption. In addition, a smart phone, a tablet PC, etc. may input a signal to a mobile device by arranging a touch pad on a display device for convenience of use.

However, a problem in that light efficiency of the display device may be lowered due to the touch panel may occur. Therefore, there is a need for a method capable of improving light efficiency without increasing power consumption.

In addition, light emitted from the organic light emitting diode is radiated, and color mixing occurs between adjacent pixels due to the radiated light, resulting in deterioration in image quality. Therefore, there is a need for a method capable of preventing color mixing.

An object of the present embodiments is to provide an organic light emitting display device capable of increasing light efficiency and a manufacturing method thereof.

Another object of the present embodiments is to provide an organic light emitting display device capable of improving image quality and a manufacturing method thereof.

In one aspect, the present embodiments define a first substrate, a pixel region on the first substrate, define the pixel region in an organic film formed therein, and a space having a height greater than a width in the first direction therein. an organic film disposed in the bank in which the array is disposed, and in the pixel region defined by the bank; and an encap for flattening upper portions of the bank and the organic layer, wherein the space is filled with a medium smaller than that of the bank.

In another aspect, the present embodiments may include forming an anode electrode in a light emitting region on a substrate and forming a first bank between the anode electrodes; forming a hole having a predetermined depth at one point of the first bank; A space stacked on top of the first bank to form a second bank narrower than the width of the first bank in the first direction, formed inside the first bank and the second bank, and filled with a smaller medium than the first bank and the second bank. It is to provide a method of manufacturing an organic light emitting display device comprising forming an organic film, depositing an organic film on an anode electrode and forming a cathode electrode on the organic film, and planarizing an upper portion of a substrate.

According to the present embodiments, it is possible to provide an organic light emitting display device capable of increasing light efficiency and a manufacturing method thereof.

According to the present embodiments, an organic light emitting display device capable of improving image quality and a manufacturing method thereof can be provided.

1 is a cross-sectional view showing a first embodiment of an organic light emitting display device according to the present embodiment.
2 is a graph showing the angle of incidence and angle of refraction of light
3 is a cross-sectional view showing a second embodiment of an organic light emitting display device according to the present embodiment.
4 is a cross-sectional view showing a third embodiment of an organic light emitting display device according to the present embodiment.
5A to 5G are conceptual views illustrating a process of manufacturing the organic light emitting display device shown in FIG. 1 .
6 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention are described in detail below with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components.

1 is a cross-sectional view showing a first embodiment of an organic light emitting display device according to the present embodiment, and FIG. 2 is a graph showing an incident angle and a refraction angle of light.

Referring to FIG. 1 , an organic light emitting display device 200 defines a pixel area in a first substrate 210 and an organic film 223 formed on the first substrate 210, and has a width in a first direction therein. It may include banks 221a and 221b in which spaces having a longer height are disposed, and an encap 2247 formed on the organic layer 223 to flatten an upper portion of the first substrate 210 . In addition, the first substrate 210 of the organic light emitting display device 200 includes a first transparent substrate 201, a plurality of thin film transistors (not shown) disposed on the first transparent substrate 201, and a plurality of gate lines. (not shown) and a plurality of data lines (not shown). However, it is not limited thereto. Accordingly, the bank and the space within the bank may become a reflective structure that reflects light, and light may be reflected by the reflective structure to increase light efficiency. Therefore, mixing of colors can be prevented so that colors can be displayed more vividly. Here, although the first substrate 210 has been described as including the first transparent substrate 201, this is exemplary and the first substrate 210 may include an opaque substrate instead of a transparent substrate.

Also, a light emitting device layer 220 may be formed on the first substrate 210 . The light emitting device layer 220 may include banks 221a and 221b and an organic layer 223 . First, a plurality of anode electrodes 202a , 202b , and 202c among the light emitting device layer 220 may be disposed in a predetermined area on the transparent substrate 201 . The anode electrodes 202a, 202b, and 202c may be connected to a drain electrode of a thin film transistor (not shown) disposed on the transparent substrate 201 to receive driving current. In addition, one anode electrode 202b may be arranged to have a certain distance from the other anode electrodes 202a and 202c adjacent thereto.

Banks 221a and 221b may be formed between the anode electrode 202b and the adjacent anode electrodes 202a and 202c. An area between the bank 221a and another neighboring bank 221b may be defined as an opening area of a pixel. However, it is not limited thereto. In addition, an organic layer 223 may be disposed on the anode electrodes 202a, 202b, and 202c and the banks 221a and 221b. The organic layer 223 may emit white light. However, it is not limited thereto.

In addition, a space 222 may be formed inside the banks 221a and 221b. The space 222 formed inside the banks 221a and 221b may be disposed at a height having a predetermined distance (D) from the upper surface of the transparent substrate 201 . In addition, the space 222 may be disposed in a form in which the height L is greater than the width W. In addition, a smaller medium than the banks 221a and 221b may be disposed in the space 222 formed inside the banks 221a and 221b. A smaller medium than the banks 221a and 221b may be air. Accordingly, light may be reflected at the boundary between the banks 221a and 221b and the space 222 . However, it is not limited thereto. The banks 221a and 221b may be made of a transparent material.

Also, a cathode electrode 224 may be disposed on the organic layer 224 . The cathode electrode 224 may be a common electrode corresponding to the plurality of anode electrodes 202a, 202b, and 202c. In addition, an encap 225 may be formed on the cathode electrode 224 to planarize the light emitting element layer 220 .

And, the second substrate 230 may be disposed on the light emitting device layer 220 . The second substrate 223 may include a second transparent substrate 231 and a plurality of color filters 233a, 233b, and 233c. A black matrix 234 may be disposed between one color filter 233b and adjacent color filters 233a and 233c, respectively. The black matrix 234 can make colors more vivid by light emitted from each of the plurality of color filters 233a, 233b, and 233c. The second substrate 220 is bonded to the upper portion of the light emitting element layer 220 using resin 232 so that the second substrate 230 and the first substrate 210 sandwich the light emitting element layer 220 therebetween. can be combined The second substrate 230 may include a plurality of color filters 233a, 233b, and 233c, and a plurality of color filters ( 233a, 233b, and 233c) may be disposed.

In the organic light emitting display device 200 implemented as described above, light emitted from the organic layer 202a can be largely divided into two paths I11 and I21. The two paths I11 and I21 are a first path I11 emitted from the organic layer 202a to the front color filter 233a and a second path I21 emitted from the organic layer 202a toward the bank 221a. can be Light emitted through the second path I21 may be a path that passes through the bank 221a, which is a transparent material, and passes through the color filter 233b of a different color adjacent thereto. When the light is emitted through the second path I21, it passes through the color filters 233b of different colors adjacent to each other, and thus the light may be mixed.

In particular, in the process of combining the first substrate 210 and the second substrate 230, misalignment in which the alignment is not accurately aligned may occur due to process errors. may occur larger.

However, when the reflective structure 222 is formed on the banks 221a and 221b, the light emitted to the second path I21 is reflected by the reflective structure 222 and the color filter 233a on the front surface of the organic layer 202a is formed. ), a third path I31 may be reflected, so that mixing of light may be reduced or prevented. Also, since the amount of light emitted to the front surface increases, the light efficiency of the organic light emitting display device may increase.

The reflective structure 222 may be the banks 221a and 221b and the space 222 disposed inside the banks 221a and 221b, respectively. The space 222 disposed inside the banks 221a and 221b may be filled with a smaller medium than the banks 221a and 221b.

In general, when two transparent materials having different densities of medium are in contact and light is irradiated, some of the irradiated light is refracted and transmitted at the boundary between the two materials, but the remaining light may be reflected at the boundary between the two materials. In particular, when light travels from the dense medium n1 to the low density medium n2, the refraction angle Oc1 of the light I1 may be greater than the incident angle Oi1 as shown in FIG. 3 . In addition, when the irradiated light I2 is incident at a specific angle Ok due to the difference in density (difference in refractive index) between the two materials, total reflection may begin. Accordingly, when the incident angle Oi2 of the irradiated light I3 is greater than the specific angle Ok, all of the light may be reflected.

Therefore, when the space 222 formed inside the banks 221a and 221b is filled with a smaller medium than the banks 221a and 221b, the light passing through the banks 221a and 221b It may be reflected at the boundary of space 222 . Accordingly, the light traveling through the second path I21 may be reflected and proceed to the third path I31, so that light corresponding to one pixel and light corresponding to another pixel may be suppressed from being mixed. In addition, the amount of light passing through the color filter 233a on the front side increases due to the light traveling through the third path I31, so that the light efficiency of the organic light emitting display device can be further increased.

Also, the banks 221a and 221b have steps in the vertical direction, and a part of the space 222 may be disposed above the steps. Light emitted from the organic layer 223 may be emitted at a predetermined angle with respect to a horizontal plane of the organic layer 223 . When the space 222 is located only under the steps, some of the lights having the second path I21 pass over the steps of the banks 221a and 221b and may not be reflected. Therefore, when a part of the space 222 is disposed above the step, light passing over the step among the lights having the second path I21 in the organic layer 223 can be reflected and the amount of reflected light can be increased. . Accordingly, the amount of light irradiated to the opening area can be increased due to the arrangement of the space 222 .

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

Referring to FIG. 3 , in the organic light emitting display device 400, the plurality of organic layers 423a, 423b, and 423c include a plurality of corresponding anode electrodes 402a, 402b, and 402c, and a plurality of anode electrodes 402a and 402b. , 402c) and adjacent banks 421a and 421b. The plurality of organic layers 423a, 423b, and 423c are formed through a fine metal mask to correspond to corresponding anode electrodes 402a, 402b, and 402c, and adjacent banks ( 421a, 421b) may be disposed on a part. In addition, a cathode electrode 424 may be disposed on the organic layers 423a, 423b, and 423c and the banks 421a and 421b. The cathode electrode 424 may be a common electrode. The organic layers 423a, 423b, and 423c may emit red (R), blue (B), and green (G) light, respectively. However, it is not limited thereto and may emit white light.

When one organic layer 402a emits green (G) light and the other adjacent organic layer 402b emits blue (B) light, the organic layers 423a, 423b, and 423c are The green (G) light and the blue (B) light may be mixed by the path I22 going to the adjacent part, which may cause color mixing. However, when a space 422 is formed inside the banks 421a and 421b and a medium smaller than that of the banks 421a and 421b is filled in the space 422, light having a path I22 passing through the bank passes through the bank 421a, 421b) Light is reflected at the boundary of the inner space 422 and the path 132 is changed in the front direction of the anode electrode 402a to prevent color mixing and increase light efficiency. Since the organic layers 423a, 423b, and 423c emit red, blue, and green light, a color filter does not need to be disposed on the second substrate 430. Therefore, the organic light emitting display device 400 can be implemented thinner. However, it is not limited thereto. In addition, the black matrix 434 is disposed at positions corresponding to the banks 421a and 421b of the second substrate 430 so that the color appears clearly, thereby making the image displayed on the organic light emitting display device 400 clearer. can

4 is a cross-sectional view showing a third embodiment of an organic light emitting display device according to the present embodiment.

Referring to FIG. 4 , the color filters 533a , 533b , and 533c and the black matrix 534 are disposed above the encap 525 to make the organic light emitting display device 500 thinner. In addition, since there is no second transparent substrate included in the second substrate, the transmittance of light is improved, so that the luminance of the organic light emitting display device 500 can be increased. Here, the organic film 523 is illustrated as covering the entire top of the banks 521a and 521b and the anode electrodes 502a, 502b and 502c, but is not limited thereto, and as shown in FIG. 3, the organic film 523 It may be disposed above the anode electrodes 502a, 502b, and 502c and on a part of the bank 521a, 521b adjacent to the anode electrodes 502a, 502b, and 502c.

5A to 5G are conceptual views illustrating a process of manufacturing the organic light emitting display device shown in FIG. 1 .

Referring to FIG. 5A, a plurality of anode electrodes 202a, 202b, and 202c are formed at predetermined intervals in a predetermined area on a first transparent substrate 201, and anode electrodes 202b and adjacent anode electrodes 202a, 202c are formed. ), the first banks 2211a and 2211b may be formed between them. The first transparent substrate 201 may include a plurality of thin film transistors, a gate line, and a data line, and one thin film transistor is connected to one anode electrode so that the driving current generated by the thin film transistor is transferred to each of the anode electrodes 202a and 202b. , 202c). Although the first transparent substrate 201 has been described as including a plurality of thin film transistors, gate lines, and data lines, it is not limited thereto, and it is possible to make the opaque substrate include a plurality of thin film transistors, gate lines, and data lines. do.

Referring to FIG. 5B , a photoresistor 270 may be coated on the first transparent substrate 201 on which the plurality of anode electrodes 202a, 202b, and 202c and the plurality of first banks 2211a and 2211b are formed. In this case, the photoresistor 270 may be applied to form a first hole h1 in an upper region of each of the first banks 2211a and 2211b. Here, the first hole h1 formed in the upper portion of the first banks 2211a and 2211b may have a narrow width in the first direction and a long width in the second direction. Accordingly, the first holes h1 respectively exposed on the first banks 2211a and 2211b may have a line shape elongated in the second direction.

Referring to FIG. 5C , a second hole h2 may be formed in the first banks 2211a and 2211b through exposure. And, the photoresistor 270 can be removed. In this case, the second hole h2 may be formed deeper than the width in the first direction.

Referring to FIG. 5D , second banks 2212a and 2212b are disposed on the first banks 2211a and 2211b in which the second hole L2 is formed. The heights of the first banks 2211a and 2211b may be lower than those of the second banks 2212a and 2212b. Widths of the second banks 2212a and 2212b in the first direction may be smaller than widths of the first banks 2211a and 2211b in the first direction. Also, in the process of arranging the second banks 2212a and 2212b, materials corresponding to the second banks 2212a and 2212b may be injected into the second holes h2 formed in the first banks 2211a and 2211b. When the material corresponding to the second banks 2212a and 2212b is injected into the second hole h2, it is attached to the bottom and sidewall of the second hole h2, so that the height of the lower part of the second hole h2 increases. Although the width of the second hole h2 in the first direction decreases, the second hole h2 is not filled and a space may remain because the width of the second hole h2 is small. In addition, the material corresponding to the second banks 2212a and 2212b fills the first banks 2211a and 2211b, and as a result, the second banks 2212a and 2212b also fill the second holes h2 formed in the first bank. Corresponding holes may occur. That is, the space 222 may be formed inside the first banks 2211a and 2211b and the second banks 2212a and 2212b. In addition, the space may be formed at a height having a constant interval (D) from the bottom surface of the first banks 2211a and 2211b. Accordingly, the bottom surface of the space may be disposed at a higher position than the bottom surface of the first bank. Also, the space 222 may be formed inside the second banks 2212a and 2212b, and the height A1 of the space 222 may be higher than the height A2 of the first banks 2211a and 2211b. The space 222 may be filled with air when the second banks 2212a and 2212b are formed on the first banks 2211a and 2211b. Accordingly, the space 222 may be filled with a smaller medium than the first banks 2211a and 2211b and the second banks 2212a and 2212b. However, it is not limited thereto.

Referring to FIG. 5E, an organic film 223 is deposited on the top of the anode electrodes 202a, 202b, and 202c and on the bank 221 composed of the first banks 2211a, 2211b, and the second banks 2212a, 2212b. can do. The organic layer 223 may emit white color by driving current. However, it is not limited thereto. Also, since the height A1 of the space 222 is formed higher than the height A2 of the first banks 2211a and 2211b, the second path (shown in FIG. 2) among the light emitted from the organic layer 223 I21) can efficiently reflect the emitted light. The organic layer 223 may be deposited on the upper portions 202a, 202b, and 202c of the anode electrodes and a portion of the bank 221 adjacent to the anode electrodes 202a, 202b, and 202c using a fine metal mask.

Referring to FIG. 5F , a cathode electrode 224 may be disposed on the organic layer 223 on which the organic layer 223 is deposited. In addition, an encap 225 may be formed on the cathode electrode 224 to planarize it and protect the organic layer 223 .

Referring to FIG. 5G , the second substrate 210 on which the color filters 223a, 223b, and 223c and the black matrix 234 are disposed can be bonded to the top of the encap 225 using resin 232. there is. In this case, one surface of the second transparent substrate 231 of the second substrate 210, on which the color filters 223a, 223b, and 223c are disposed, may face the first substrate 210. However, it is not limited thereto, and as shown in FIG. 5 , it is also possible to arrange the color filters 223a, 223b, and 223c on the cathode electrode 225.

Accordingly, light emitted from the organic layer 223 may be reflected at the boundary between the banks 221a and 221b and the space 222 formed inside the banks 221a and 221b. Accordingly, light efficiency can be increased and light emitted from the organic layer 223 can be prevented from being mixed by reflecting light emitted from the organic layer 223 to another color filter adjacent to the color filter instead of the color filter disposed on the front side.

6 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment.

Referring to FIG. 6 , the manufacturing method of the organic light emitting display device may include forming an anode electrode on a first substrate and forming a first bank between the anode electrodes to divide the light emitting area ( S600).

Then, a hole having a predetermined depth may be formed in the first bank (S610). The hole may reach the bottom surface of the first bank. The hole formed in the first bank may be formed using a photoresistor. A photoresistor may be formed on the first bank, but at a point where a hole is to be formed, the photoresistor may not cover the first bank, and the first bank may be planted to form a hole.

Then, a second bank stacked on top of the first bank and having a narrower width than the width of the first bank in the first direction may be formed, and a space may be formed inside the first bank and the second bank (S620). The hole formed in the first bank may be narrow and deep, so that in the process of disposing the second bank on the first bank, the material corresponding to the second bank passes through the hole to the hole formed in the first bank. You can also go inside. However, since the width of the hole is narrow, the inside of the hole is not filled and a space is formed inside the first bank. In addition, since the material corresponding to the second bank is also inserted into the first bank, a space is formed in the second bank on top of the space formed in the first bank, so that the first bank and the second bank are one. A space of can be formed. The space can be filled with a smaller medium than the first bank and the second bank. When the space is filled with a rare medium, light can be reflected at the boundary between the first bank or the second bank and the space. The quenching medium filling the space may be air. However, it is not limited thereto.

And, an organic film may be deposited on the anode. And, a cathode electrode may be formed on the organic layer (S630). An organic film may be disposed on the anode electrode and the bank. In this case, the organic layer may emit white light. However, it is not limited thereto. Also, an organic layer may be disposed on an anode electrode and a part of a bank by using a fine metal mask. A cathode electrode may be disposed on the organic layer. The cathode electrode may be a common electrode corresponding to each anode electrode.

Then, the upper portion of the first substrate may be planarized (S640). The planarization of the upper portion of the first substrate may be performed using an encap. In addition, the organic film can be protected by encapsulation. In addition, a second substrate may be attached to the flattened first substrate. The second substrate may be attached to the encap by being bonded using resin. The second substrate may include a transparent substrate, a color filter, and a black matrix. However, it is not limited thereto, and it is also possible to arrange a color filter and a black matrix on the encaps. A color filter is disposed on the second substrate so that light emitted from the organic layer passes through the color filter to become any one of red, blue, and green light. In addition, some of the light emitted from the organic layer may be prevented from being reflected by the reflective structure formed in the bank and mixed with light emitted from the adjacent organic layer. Therefore, light efficiency can be increased.

The above description and accompanying drawings are merely illustrative of the technical idea of the present invention, and those skilled in the art can combine the configuration within the scope not departing from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

200: organic light emitting display device
201: first transparent substrate
202a, 202b, 202c: anode electrode
210: first substrate
220: light emitting element layer
221a, 221b: bank
222: space
223 organic film
224: Incap
225: cathode electrode
230: second substrate
231: second transparent substrate
232: Resin
233a, 233b, 233c: color filter
234: Black Matrix

Claims (7)

a first substrate;
banks defining a pixel area on the first substrate, provided in plurality and spaced apart from each other;
a plurality of anode electrodes respectively disposed between the banks;
an organic film disposed in the pixel area defined by the bank; and
Including an encap for planarizing an upper portion of the bank and the organic layer,
The bank has a height longer than the width and a space filled with a smaller medium than the bank is disposed therein,
The bank includes a first bank and a second bank stacked on the first bank and having a narrower width than the first bank, and a bottom surface of the space is disposed at a higher position than a bottom surface of the first bank. , A part of the space is formed in the second bank. delete According to claim 1,
The height of the first bank is lower than that of the second bank. According to claim 1,
An organic light emitting display device wherein color filters are formed on the encaps at positions corresponding to the anode electrodes. According to claim 1,
The organic light emitting display device of claim 1 , wherein the exhausting medium includes air. forming an anode electrode in a light emitting region on a substrate, and forming a first bank having a predetermined height between the anode electrodes;
forming a hole having a predetermined depth in the first bank;
A second bank stacked on top of the first bank and having a narrower width than the first bank is formed, and is formed in the first bank and the second bank and is smaller than the first bank and the second bank. forming the filled space;
depositing an organic film on the anode electrode; and
and forming an encap on the substrate on which the organic film is formed. According to claim 6,
The method of manufacturing an organic light emitting display device in which the exhausting medium includes air.

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