KR20170023662A - Display device and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a display device which comprises: a thin film transistor including a pixel prepared on a substrate wherein the thin film transistor is prepared on a light emitting region defined on the substrate; a first electrode connected to the thin film transistor; a light emitting diode chip prepared on the first electrode; and a second electrode connected to the light emitting diode chip.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a display device,

The present invention relates to a display device and a method of manufacturing the same.

The flexible display device has advantages in that a pixel cell is implemented on a thin flexible substrate such as a plastic substrate and can display an image desired to be folded or rolled up like a paper. And research and development on this is proceeding.

The display device may be a flexible liquid crystal display device, a flexible organic light emitting display device, a flexible electrophoretic display device, or a flexible electronic wet display device a flexible electro-wetting display device) and the like.

1 is a cross-sectional view illustrating a conventional display device.

Referring to FIG. 1, a conventional display device includes a substrate 10, a thin film transistor (TFT), a passivation layer 30, a planarization layer 31, a first electrode 32, a bank layer 33, 34), and a second electrode (35).

The thin film transistor (TFT) is disposed on the substrate 10 and includes an active layer 20, a gate insulating layer 21, a gate electrode 22, an interlayer insulating layer 23, a source electrode 24, And a drain electrode (25).

The passivation layer 30 and the planarization layer 31 are disposed on the thin film transistor TFT and contact holes for connecting the first electrode 32 and the drain electrode 25 are formed.

The first electrode 32 is connected to the drain electrode 25 from the contact hole.

The bank layer 33 is disposed on the planarization layer 31 so as to overlap with the first electrode 32.

The organic light emitting layer 34 is disposed on the first electrode 32. The organic light emitting layer 34 emits light by the current flowing between the first and second electrodes 32 and 35.

The second electrode 35 is disposed on the organic light emitting layer 34 so as to cover the first electrode 32.

In the conventional display device, the organic light emitting layer 34 emits light by using the organic light emitting layer 34. At this time, the organic light emitting layer 34 may deteriorate due to the characteristics of the organic material, decrease in luminance, and reliability due to moisture permeation.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a display device using a micro light emitting diode chip using an inorganic material instead of an organic material and a method of manufacturing the same.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an aspect of the present invention, there is provided a display device and a method of manufacturing the same, wherein a light emitting diode chip is used instead of the organic light emitting layer to prevent problems of organic materials.

A thin film transistor provided on a light emitting region defined on the substrate; a first electrode connected to the thin film transistor; a light emitting diode chip provided on the first electrode; and a second electrode connected to the light emitting diode chip, A display device including an electrode is provided.

According to the present invention, by using a light emitting diode chip, which is an inorganic material, in place of the organic light emitting layer which is an organic material, it is possible to prevent degradation due to the use of organic materials, decrease in luminance, and decrease in reliability due to moisture permeation.

According to the present invention, a process alignment margin is ensured by the inclined surface structure of the through-holes provided in the first bank layer.

In addition, according to the present invention, when a phosphor containing a resin is disposed on a light emitting diode chip, light can be spread more easily due to a resin serving as a convex lens.

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

1 is a cross-sectional view illustrating a conventional display device.
2 is a schematic plan view of a display device according to an exemplary embodiment of the present invention, in which one unit pixel is enlarged.
3 is a schematic cross-sectional view of a display device according to one example of the present invention, taken along the line I-I 'of FIG.
4 is a schematic cross-sectional view of a display device according to another example of the present invention, taken along line I-I 'of FIG.
5 is a schematic cross-sectional view of a display device according to another example of the present invention, taken along the line I-I 'of FIG.
6A to 6D are cross-sectional views illustrating a method of manufacturing a display device according to an exemplary embodiment of the present invention.
7A to 7C are cross-sectional views illustrating a method of manufacturing a display device according to another example of the present invention.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms. It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one. The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

Hereinafter, preferred embodiments of a light source module, a backlight unit including the light source module, and a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

2 is a schematic plan view of a display device according to an exemplary embodiment of the present invention, in which one unit pixel is enlarged.

2, a display device according to an exemplary embodiment of the present invention includes a plurality of pixels Pr, Pg, and Pb for each pixel region defined by intersection of a plurality of gate lines GL and a plurality of data lines DL. . Here, three adjacent pixels Pr, Pg, and Pb constitute one unit pixel.

Each of the plurality of pixels Pr, Pg, and Pb includes a transmissive area TA and a light emitting area EA.

The transmissive area TA is provided on one side of the pixel to transmit light incident from the outside. That is, the transmissive area TA is made of a transparent material to transmit incident light. Thus, the transmissive area TA allows the object or the background located on the back surface or the front surface to be viewed.

The light emitting area EA may be defined as an area for displaying an image, which is the remaining part of the pixel excluding the transmissive area TA. This luminescent area EA displays an image.

At this time, the light emitting region EA includes a red light emitting portion RE, a green light emitting portion GE, and a blue light emitting portion BE.

The display device according to an exemplary embodiment of the present invention displays an image through the light emitting region EA or serves as a transparent display according to light transmission through the transmissive region TA.

3 is a schematic cross-sectional view of a display device according to one example of the present invention, taken along the line I-I 'of FIG.

3, a display device according to an exemplary embodiment of the present invention includes a lower substrate 100, a light shield 130, a buffer layer 150, a thin film transistor (TFT), a passivation layer 300, And includes a bank layer 310, a first electrode 320, a light emitting diode chip 330, a planarization layer 340, a second electrode 350, a second bank layer 360, and an upper substrate 400 .

The lower substrate 100 may be made of a thin plastic material as a flexible substrate. For example, the lower substrate 100 may include at least one selected from the group consisting of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN) (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC) and cellulose acetate propionate And cellulose acetate propionate (CAP).

The light shielding layer 130 is disposed on the lower substrate 100 so as to overlap with the thin film transistor TFT. The light shielding layer 130 blocks light incident from the bottom to the thin film transistor (TFT), thereby preventing deformation of the thin film transistor (TFT) from light.

On the other hand, the light shielding layer 130 is not necessarily required, and the light shielding layer 130 may be omitted in the display device according to an exemplary embodiment of the present invention.

The buffer layer 150 is disposed on the lower substrate 100. The buffer layer 150 serves to prevent diffusion of a material contained on the lower substrate 100 into the thin film transistor TFT during a high temperature process during the manufacturing process of the thin film transistor TFT. In addition, the buffer layer 150 can prevent moisture and moisture from penetrating into the inside. The buffer layer 150 may be formed of silicon oxide, silicon nitride, or the like. At this time, the buffer layer 150 may be formed of one or more layers, and may be omitted in some cases.

The thin film transistor TFT is disposed on the buffer layer 150 and includes an active layer 200, a gate insulating layer 210, a gate electrode 220, an interlayer insulating layer 230, a source electrode 240, A drain electrode 250, and an antireflection layer 260.

The active layer 200 is disposed on the buffer layer 150 so as to overlap with the light shielding layer 130. The active layer 200 may be made of an oxide semiconductor such as In-Ga-Zn-O (IGZO), but is not necessarily limited thereto, and may be made of a silicon-based semiconductor.

The gate insulating layer 210 is disposed on the active layer 200. That is, the gate insulating layer 210 is disposed between the active layer 200 and the gate electrode 220 to insulate the gate electrode 220 from the active layer 200. The gate insulating layer 210 may be made of an inorganic insulating material such as silicon oxide or silicon nitride. However, the gate insulating layer 210 may be formed of an organic insulating material such as photo acryl or benzocyclobutene (BCB) It is possible.

The gate electrode 220 is disposed on the gate insulating layer 210 so as to overlap with the active layer 200. The gate electrode 220 may be formed of a material selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Ne, Cu, Alloy, and may be composed of a single layer of the metal or alloy or multiple layers of two or more layers.

The interlayer insulating layer 230 is disposed on the buffer layer 150, the active layer 200, and the gate electrode 220. The interlayer insulating layer 230 may be made of an inorganic insulating material such as silicon oxide or silicon nitride, but is not necessarily limited to, but may be made of an organic insulating material such as photo acryl or benzocyclobutene (BCB) It is possible.

The source electrode 240 and the drain electrode 250 are provided on the interlayer insulating layer 230 while facing each other. At this time, each of the source electrode 240 and the drain electrode 250 is connected to the active layer 200 through the contact hole formed in the interlayer insulating layer 230. The source electrode 240 and the drain electrode 250 may be formed of one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, (Cu), or an alloy thereof, and may be composed of a single layer of the metal or alloy or multiple layers of two or more layers.

The antireflection layer 260 surrounds the lower surface of the light shield layer 130, the source electrode 240, the drain electrode 250, and the gate electrode 220. The antireflection layer 260 low-reflects the light incident on the lower surface to darken the color tone seen in the lower direction of the lower substrate 100. The antireflection layer 260 may be formed of a combination of a transparent conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like and a common metal (thickness of 1 to 25 nm) And may be omitted in some cases.

The passivation layer 300 is disposed entirely on the interlayer insulating layer 230, the source electrode 240, and the drain electrode 250. The passivation layer 300 may be made of an inorganic insulating material such as silicon oxide or silicon nitride. However, the passivation layer 300 may be formed of an organic insulating material such as photo acryl or benzocyclobutene (BCB) have.

The first bank layer 310 is disposed on the passivation layer 300 so as to overlap the TFTs. At this time, the first bank layer 310 is provided with a through hole which penetrates to the passivation layer 300 and exposes a part of the drain electrode 250. The through-hole separates the first bank layer 310 into two, and the two surfaces of the first bank layer 310 formed by the separation of the first bank layer 310 form an inclined surface that narrows the through-hole toward the lower side do. This first bank layer 310 can prevent a poor color washout between neighboring pixels and improve the reliability of the panel. At this time, the first bank layer 310 may be formed of an organic insulating material such as polyimide, photo acryl, or benzocyclobutene (BCB), but is not limited thereto.

The first electrode 320 is disposed in a space provided by the through hole of the first bank layer 310. That is, the first electrode 320 is disposed on the drain electrode 250 and electrically connected to the thin film transistor TFT. The first electrode 320 may function as an anode electrode, and may also serve to fix the light emitting diode chip 330. The first electrode 320 according to an exemplary embodiment may be formed of a conductive epoxy.

The light emitting diode chip 330 is disposed in a through hole provided in the first bank layer 310. That is, the light emitting diode chip 330 is disposed between the two first bank layers 310. One surface of the light emitting diode chip 330 is in contact with the first electrode 320 and the other surface of the light emitting diode chip 330 is exposed to the outside of the first bank layer 310. At this time, the light emitting diode chip 330 is narrowed in width from the top to the bottom, and the side surface of the light emitting diode chip 330 is inclined to become narrower toward the lower side. Accordingly, the light emitting diode chip 330 is slidably mounted on the inclined surface formed in the through hole of the first bank layer 310. The light emitting diode chip 330 has a structure of a through hole provided in the first bank layer 310 A process aligning margin is ensured. The light emitting diode chip 330 may be one of a red light emitting diode chip, a green light emitting diode chip, and a blue light emitting diode chip. As described above, the display device according to an exemplary embodiment of the present invention uses the light emitting diode chip 330 made of an inorganic material, thereby preventing deterioration of the organic light emitting layer made of an organic material, deterioration in luminance, have.

The planarization layer 340 is disposed on the first bank layer 310 and the light emitting diode chip 330. The planarization layer 340 uniformly compensates a step generated by the light emitting diode chip 330 on the first bank layer 310 to flatten the surface. The planarization layer 340 prevents contact between the second electrode 350 and the first electrode 320 disposed on the upper surface of the LED chip 330. That is, the flattening layer 340 prevents the second electrode 350, which is a strong linear material, from digging between the light emitting diode chip 330 and the first bank layer 310 to be in contact with the first electrode 320 do. The planarization layer 340 may be an acrylic resin or a polyimide resin, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof, but is not limited thereto.

The second electrode 350 is disposed on the first bank layer 310 and connected to the light emitting diode chip 330 through a contact hole formed in the first bank layer 310. The second electrode 350 may serve as a cathode. At this time, the second electrode 350 may be formed of a transparent conductive material, for example, indium tin oxide (ITO) or indium zinc oxide (IZO).

The second bank layer 360 is disposed on the second electrode 350. The second bank layer 360 may be formed of an organic insulating material such as polyimide, photo acryl, or benzocyclobutene (BCB), but the present invention is not limited thereto.

The upper substrate 400 is disposed on the second bank layer 360. The upper substrate 400 is made of a transparent flexible material like the lower substrate 100.

By using the light emitting diode chip 330 made of an inorganic material, the display device according to an exemplary embodiment of the present invention can prevent deterioration, lowering of brightness, and lowering of reliability due to moisture permeation, unlike the organic light emitting layer composed of an organic material have.

4 is a schematic cross-sectional view of a display device according to another example of the present invention, taken along line I-I 'of FIG. 4 is the same except that the phosphor 370 and the color filter 380 are added to the display device according to Fig. Accordingly, only the phosphor 370 and the color filter 380 will be described in the following description, and redundant description of the same constitution will be omitted.

The phosphor 370 is disposed in a through hole formed in the second bank layer 360. That is, the phosphor 370 is disposed on the second electrode 350 so as to overlap the light emitting diode chip 330. The phosphor 370 may be one or more color fluorescent materials for generating white light in accordance with the color light emitted from the light emitting diode chip 330. At this time, when the light emitting diode chip 330 emits blue light, the phosphor 370 absorbs a part of blue light to generate white light. The phosphor 370 of the display device according to another exemplary embodiment of the present invention may use a YAG phosphor (YAG: Ce) doped with cerium (Ce) to yttrium aluminum garnet (YAG). When the YAG fluorescent material is applied, the light emitting diode chip 330 may generate white light when the blue light emitting diode chip 330 is used. At this time, the phosphor 370 may further include a resin. The resin is a viscous material and can be formed convexly in the form of a lens. Accordingly, when the fluorescent material 370 containing a resin is disposed on the light emitting diode chip 330, the resin can act as a convex lens to spread the light more effectively.

The color filter 380 is disposed on the second bank layer 360 so as to overlap with the phosphor 370 and the light emitting diode chip 330. The color filter 380 may be a red, green, or blue color filter corresponding to each pixel region.

The display device according to another exemplary embodiment of the present invention uses the light emitting diode chip 330 made of an inorganic material to prevent deterioration in luminance, have.

5 is a schematic cross-sectional view of a display device according to another example of the present invention, taken along the line I-I 'of FIG. This display device according to Fig. 5 is the same except that a color filter 380 is added to the display device according to Fig. Accordingly, only the color filter 380 will be described in the following description, and redundant description of the same configuration will be omitted.

The light emitting diode chip 330 of the display device according to another example of the present invention is a white light emitting diode chip emitting white light.

The color filter 380 is disposed on the second bank layer 360 so as to overlap with the phosphor 370 and the light emitting diode chip 330. The color filter 380 may be a red, green, or blue color filter corresponding to each pixel region. Accordingly, the color filter 380 allows the light emitting diode chip 330 emitting white light to emit red, green, and blue light for each pixel region.

The display device according to another exemplary embodiment of the present invention uses the light emitting diode chip 330 made of an inorganic material, thereby preventing deterioration, lowering of luminance, and lowering of reliability due to moisture permeation unlike the organic light emitting layer composed of an organic material .

6A to 6D are cross-sectional views illustrating a method of manufacturing a display device according to an exemplary embodiment of the present invention. Hereinafter, repetitive description of the repetitive portions in the materials, structures and the like of each constitution will be omitted.

First, as shown in FIG. 6A, a lower substrate 100 is formed. The lower substrate 100 is a thin flexible substrate. Therefore, a base substrate 50 of a rigid material is attached to the lower surface of the lower substrate 100 to support the lower surface of the lower substrate 100.

Then, a light shielding layer 130, a buffer layer 150, and a thin film transistor (TFT) are formed on the lower substrate 100.

More specifically, a method of manufacturing a thin film transistor (TFT) will be described below.

First, an active layer 200, a gate insulating layer 210, and a gate electrode 220 are sequentially formed on a lower substrate 100. An antireflection layer 260 is formed between the gate insulating layer 210 and the gate electrode 220. Then, an interlayer insulating layer 230 is formed on the buffer layer 150, the active layer 200, and the gate electrode 220 as a whole. Two contact holes are formed in the interlayer insulating layer 230 so that the source electrode 240 and the drain electrode 250 formed on the interlayer insulating layer 230 are connected to the active layer 200 do. The antireflection layer 260 may be formed under the light-shielding layer 130, the source electrode 240, and the drain electrode 250, as the case may be.

6B, the passivation layer 300 is formed entirely on the interlayer insulating layer 230 so as to cover the source electrode 240 and the drain electrode 250. Then, as shown in FIG. Then, a first bank layer 310 is formed on the passivation layer 300, and a through hole is formed so that a part of the drain electrode 250 is exposed. At this time, the through-hole separates the first bank layer 310 into two, and the two surfaces of the first bank layer 310 formed by the separation of the first bank layer 310 are inclined downward as the through- . Then, a first electrode 320 is formed in the through hole.

Then, as shown in FIG. 6C, the light emitting diode chip 330 is mounted on the through hole of the first bank layer 310. The light emitting diode chip 330 is slidably mounted along an inclined surface formed in the through hole of the first bank layer 310. Then, the first electrode 320 is cured by a thermal curing process. As the first electrode 320 is cured, the light emitting diode chip 330 is fixed to the through hole.

6D, a planarization layer 340 is formed on the first bank layer 310 so as to cover the light emitting diode chip 330. Next, as shown in FIG. Then, a through hole is formed in the planarization layer 340 so that a part of the light emitting diode chip 330 is exposed. Then, a second electrode 350 is formed on the planarization layer 340 so as to be connected to the light emitting diode chip 330 through the through hole.

Then, a second bank layer 360 and an upper substrate 400 are sequentially formed on the second electrode 350. Then, the base substrate 50 attached to the lower surface of the lower substrate 100 is removed by a laser process.

In the manufacturing process of the display device according to the exemplary embodiment of the present invention, an alignment margin is secured during the process of mounting the light emitting diode chip 330 by the inclined surface structure of the through holes provided in the first bank layer 310.

7A to 7C are cross-sectional views illustrating a method of manufacturing a display device according to another example of the present invention, which relates to the manufacturing method of the display device according to the aforementioned FIG. Hereinafter, repetitive description of the repetitive portions in the materials, structures and the like of each constitution will be omitted.

7A, a lower substrate 100, a light shielding layer 130, a buffer layer 150, a thin film transistor (TFT), a passivation layer 300, a first bank layer 310, The light emitting diode chip 320, and the light emitting diode chip 330 in this order. Such a process is the same as that of FIGS. 5A to 5C, and thus a duplicate description will be omitted.

Then, a second bank layer 360 is formed on the second electrode 350 as shown in FIG. 7B. Then, a through hole is formed in the second bank layer 360 overlapping with the light emitting diode chip 330 to expose a part of the second electrode 350. Then, the phosphor 370 is injected into the through-hole. When the fluorescent material 370 includes a resin, the resin is formed into a convex lens shape, and the resin is cured through a heat curing process.

Then, as shown in FIG. 7C, a color filter 380 is formed on the second bank layer 360 so as to overlap with the phosphor 370. Then, the upper substrate 400 is formed on the second bank layer 360 so as to cover the color filter 380. Then, the base substrate 50 attached to the lower surface of the lower substrate 100 is removed by a laser process.

Meanwhile, the display device according to another example of the present invention can be formed by excluding the step of forming the phosphor 370 in the manufacturing method of the display device according to another example of the present invention.

In the manufacturing process of the display device according to the exemplary embodiment of the present invention, an alignment margin is secured during the process of mounting the light emitting diode chip 330 by the inclined surface structure of the through holes provided in the first bank layer 310. In addition, when the fluorescent material 370 containing a resin is disposed on the light emitting diode chip 330, the resin can act as a convex lens so that the light can spread more easily.

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. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

100: Lower substrate TFT: Thin film transistor
300: passivation layer 310: first bank layer
320: first electrode 330: light emitting diode chip
340: planarization layer 350: second electrode
360: second bank layer 370: phosphor
380: color filter 400: upper substrate

Claims (14)

A pixel provided on the substrate,
A thin film transistor provided on a light emitting region defined in the substrate;
A first electrode connected to the thin film transistor;
A light emitting diode chip provided on the first electrode;
And a second electrode connected to the light emitting diode chip. The method according to claim 1,
Wherein the pixel includes a transmissive region adjacent to the light emitting region. The method according to claim 1,
Wherein the first electrode comprises a conductive epoxy. The method according to claim 1,
Wherein the light emitting diode chip emits one of red light, green light, and blue light. The method according to claim 1,
And a color filter provided on the second electrode so as to overlap the light emitting diode chip,
Wherein the light emitting diode chip emits white light. The method according to claim 1,
A phosphor provided on the second electrode so as to overlap the LED chip; And
And a color filter provided on the phosphor. The method according to claim 6,
The light emitting diode chip emits blue light,
And the phosphor converts the blue light into white light and emits it. 8. The method according to any one of claims 1 to 7,
The thin-
An active layer provided on the substrate;
A gate electrode formed on the active layer;
An interlayer insulating layer covering the active layer and the gate electrode;
A source electrode provided on the interlayer insulating layer and connected to one side of the active layer; And
And a drain electrode provided on the interlayer insulating layer and connected to the other side of the active layer and connected to the first electrode. 9. The method of claim 8,
And an antireflection layer provided between each of the source electrode and the drain electrode and the interlayer insulating layer. (A) forming a thin film transistor on a substrate;
(B) forming a first electrode connected to the thin film transistor;
(C) placing a light emitting diode chip on the first electrode; And
(D) forming a second electrode connected to the light emitting diode chip. 11. The method of claim 10,
Wherein the light emitting diode chip emits one of red light, green light, and blue light. 11. The method of claim 10,
(E) forming a color filter on the second electrode overlapping the light emitting diode chip,
Wherein the light emitting diode chip emits white light. 11. The method of claim 10,
(E) forming a phosphor on the second electrode overlapped with the light emitting diode chip; And
And (F) forming a color filter on the phosphor. 14. The method of claim 13,
The light emitting diode chip emits blue light,
Wherein the phosphor converts the blue light into white light and emits the white light.

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