JP2004186042A - Organic el display panel, manufacturing method of unfixed side substrate of organic el display panel and manufacturing device of unfixed side substrate of organic el display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working technology of a non-fixed side substrate preferable when adopted for an organic EL display panel of a top emission type having a superior image quality. <P>SOLUTION: Among packages 2 of the organic EL display of the top emission type in which the EL element part 1 is housed inside, a transparent non-fixed side substrate 22 of the side where the EL element part 1 is not fixed is manufactured. Onto the surface of a glass plate G, positioned at the prescribed position in a treatment container 3 to which a photoresist is applied, an etching solution supply system 6 supplies the etching solution L of a fluorinated acid series by injecting the solution from a nozzle 5 to upward in the form of mist, and the etching is carried out. The recess part whose fringe is a rib 220 is formed on the surface of the glass plate G. The glass plate G moves to the fixed nozzle 5 by a moving mechanism, and the etching solution L is homogeneously supplied. Because the flatness of the surface 221 of the inner side of the non-fixed side substrate 22 is higher, the quality of the displayed image becomes higher. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention of the present application relates to an organic EL display that has recently been promising as a flat panel display (FPD).
[0002]
[Prior art]
The organic EL display is a display using an organic EL element. The organic EL element has a structure in which an organic thin film is sandwiched between a pair of electrodes, and at least one of them is a transparent electrode such as indium-tin oxide (ITO) for convenience of extracting light. A DC voltage is applied to the pair of electrodes, and electrons are injected from one side and holes are injected from the other side into the organic thin film. These carriers recombine and excite in the organic thin film, and when this returns to the ground state, light emission occurs.
[0003]
Since an organic EL display emits light by itself, a backlight such as a liquid crystal display is unnecessary. In addition, it is excellent in high-speed response, and it is easy to reduce the thickness and drive voltage. Also, the manufacturing process is simpler than a liquid crystal display or the like. For these reasons, it is drawing attention as a next-generation display technology, and practical application to mobile phones and the like has already begun.
[0004]
The structure of the current organic EL display panel will be described with reference to FIG. FIG. 5 is a schematic sectional view of a current organic EL display panel. The organic EL display panel shown in FIG. 5 includes an EL element portion 1 including a pair of electrodes 11 and 12 and an organic thin film 13 sandwiched between the pair of electrodes 11 and 12, and a package 2 containing the EL element portion 1 therein. Consisting of Note that the organic EL display panel refers to an organic EL display that includes a package 2 excluding a drive circuit and the like and components inside the package.
[0005]
For convenience of extracting light, at least one of the pair of electrodes 11 and 12 is a transparent electrode such as ITO. In the case of an active type for driving each pixel, a thin film transistor (TFT) is formed as one electrode. The package 2 includes a fixed substrate 21 to which the EL element 1 is fixed, and a non-fixed substrate 22 to which the EL element 1 is not fixed. The current organic EL display is a so-called bottom emission type, and the example shown in FIG. 5 also belongs to this. That is, the fixed-side substrate 21 is made of glass and transparent. Light from the EL element section 1 passes through the fixed substrate 21 and is emitted. That is, the fixed-side substrate 21 is located on the side of the viewer of the image.
[0006]
[Problems to be solved by the invention]
The bottom-emission type organic EL display panel as shown in FIG. 5 emits light through the fixed substrate 21 of the package 2 and thus has a problem that light utilization efficiency is poor. That is, a circuit for driving the EL element unit 1 is formed on the fixed substrate 21, and has a lower light transmittance than an ordinary simple transparent body. To solve this problem, a top emission type organic EL display panel is effective, and it is considered that the top emission type is promising in the future. FIG. 6 is a schematic sectional view of a top emission type organic EL display panel.
In the top emission type, as shown in FIG. 6, light from each EL element section 1 is emitted through the non-fixed side substrate 22 as it is. Since the non-fixed side substrate 22 does not fix the EL element section 1, it can be made a simple transparent body and can have a high transmittance. Therefore, the light use efficiency is higher than that of the bottom emission type.
[0007]
Here, as shown in FIG. 6, in the top emission type, it is necessary to form a rib on the peripheral edge of the non-fixed side substrate 22. The ribs are formed by processing a transparent glass plate on which the non-fixed-side substrate 22 is based. At present, the formation of ribs by the sandblasting method is being studied (see Semiconductor FPD World, January 2002, p. 116-118).
However, according to the sandblasting method, there is a disadvantage that the flatness of the processed surface is poor as shown in an enlarged view in FIG. In particular, in the case of a structure in which light is extracted through the portion as in the case of a top emission type, there is a problem that unevenness of the surface subjected to sandblasting causes image unevenness and image quality flicker. In addition, according to the sandblasting method, microcracks tend to occur. Therefore, a problem in strength and a problem in durability are likely to occur. This point does not change even with the bottom emission type.
[0008]
The invention of the present application has been made to solve such a problem, and has a technical significance of providing a processing technology of a non-fixed-side substrate suitable for being adopted in a top emission type organic EL display panel having excellent image quality. It has.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present application provides an organic thin film by applying a voltage to the organic thin film with the pair of electrodes sandwiching the organic thin film at least one of which is a transparent electrode. An organic EL display panel,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element portion is fixed, and a non-fixed substrate on which the EL element is not fixed,
The non-fixed side substrate has a concave portion in which the EL element portion is located, and the periphery of the concave portion is a rib. The concave portion is formed by supplying the etching liquid in a mist state. It has the structure that it is formed by.
Further, in order to solve the above-mentioned problem, the invention according to claim 2 has a structure in which at least one of the pair of electrodes is a transparent electrode, and the organic thin film is sandwiched between the pair of electrodes. An organic EL display panel,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element portion is fixed, and a non-fixed substrate on which the EL element is not fixed,
The non-fixed side substrate is transparent, and is a top emission type that emits light from the EL element unit through the non-fixed side substrate,
Further, the non-fixed side substrate has a concave portion whose bottom surface is a light transmitting surface, and the peripheral edge of the concave portion is a rib, and this concave portion is formed by supplying the etching liquid in a mist state. It has a configuration that it is formed by etching.
According to a third aspect of the present invention, there is provided an organic EL display panel package having a non-fixed side, which is a side on which the EL element portion is not fixed, of a package of the organic EL display panel having the EL element portion housed therein. The method,
A step of applying a resist on the glass plate in a predetermined pattern,
Supplying a hydrofluoric acid-based etchant in the form of a mist to the glass plate coated with the resist, and etching the glass plate to form a concave portion having a peripheral edge as a rib.
According to another aspect of the present invention, a transparent non-transparent non-fixed EL element portion of a package of an organic EL display panel of a top emission type in which an EL element portion is housed. A method of manufacturing a fixed-side substrate,
A step of applying a resist on the glass plate in a predetermined pattern,
Supplying a hydrofluoric acid-based etchant in the form of a mist to the glass plate coated with the resist, and etching the glass plate to form a concave portion having a peripheral edge as a rib.
According to another aspect of the present invention, there is provided an apparatus for manufacturing a non-fixed substrate, which is a side on which an EL element portion is not fixed, of a package of an organic EL display having an EL element portion housed therein. And
A nozzle provided at a position facing the surface of the glass plate where the resist is applied and positioned at a predetermined position, and a hydrofluoric acid-based etchant is sprayed from the nozzle and supplied to the surface of the glass plate in a mist form to perform etching. With an etchant supply system,
It has a configuration in which a recess whose peripheral edge is a rib is formed on the surface of a glass plate by etching.
According to another aspect of the present invention, there is provided a package of a top emission type organic EL display in which an EL element portion is housed. An apparatus for manufacturing a side substrate,
A nozzle provided at a position facing the surface of the glass plate where the resist is applied and positioned at a predetermined position, and a hydrofluoric acid-based etchant is sprayed from the nozzle and supplied to the surface of the glass plate in a mist form to perform etching. With an etchant supply system,
It has a configuration in which a recess whose peripheral edge is a rib is formed on the surface of a glass plate by etching.
According to a seventh aspect of the present invention, in order to solve the above problem, in the configuration of the fifth or sixth aspect, the nozzle is provided below a glass plate located at a predetermined position, and an etching solution is provided above the glass plate. Is sprayed, adhered to the lower surface of the glass plate, and etched.
In order to solve the above-mentioned problem, the invention according to claim 8 is the arrangement according to claim 5, 6, or 6, wherein the nozzle or the glass plate is relatively moved to uniformly supply the etching liquid. It has a configuration that a mechanism is provided.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter, embodiments) will be described.
First, an embodiment of the invention of an organic EL display panel will be described. FIG. 1 is a schematic sectional view of the organic EL display panel of the present invention. The organic EL display panel shown in FIG. 1 is of a top emission type, and its basic structure is the same as that shown in FIG. The difference lies in the non-fixed side substrate 22. In this embodiment, the concave portion is formed by a mist etching method which is performed by supplying an etching solution in a mist state. The cross-sectional shape of the rib 220 is different from that formed by the sandblasting method shown in FIG. That is, in the present embodiment, the inner side (the side closer to the center of the panel) of the rib 220 has a tapered surface. It is preferable that the angle of the tapered surface (indicated by θ in FIG. 1) is about 80 to 87 degrees. With such a tapered surface, the strength of the rib 220 can be increased while sufficiently securing the area of the bottom of the concave portion.
[0011]
In the embodiment shown in FIG. 1, the flatness of the inner side surface 221 of the non-fixed side substrate 22 is extremely high as shown in an enlarged manner in FIG. This is an effect of the mist etching method. The flatness of the outer surface 222 of the non-fixed substrate 22 can be ensured by arbitrarily selecting various polishing methods. The inner surface is difficult to polish due to the presence of the ribs 220. In this embodiment, since the mist etching method is used, the flatness is extremely high.
The non-fixed side substrate 22 of the present embodiment is a member that is transparent and emits light therethrough because it is for a top emission type organic EL display. In this embodiment, the quality of the displayed image is high because the flatness of the surfaces 221 and 222 is high.
[0012]
Next, an embodiment of a method of manufacturing a non-fixed-side substrate and an embodiment of a device of a non-fixed-side substrate manufacturing apparatus will be described.
FIG. 2 is a diagram illustrating a schematic configuration of a non-fixed-side substrate manufacturing apparatus according to the embodiment. The apparatus shown in FIG. 2 includes a processing container 3 in which an etching process is performed, a transport system 4 for loading the glass plate G into the processing container 3 and unloading the glass plate G after the processing, and is located in the processing container 3. A nozzle 5 provided at a position facing the surface of the glass plate G, and an etchant supply system 6 for etching by supplying a hydrofluoric acid-based etchant L to the surface of the glass plate G through the nozzle 5 in a mist state. Have.
[0013]
The transport system 4 is of a roller type in the present embodiment. That is, the transport system 4 is constituted by a large number of transport rollers 41 provided along the transport line. In the present embodiment, the glass plate G is transported while the surface to be etched of the glass plate G faces downward. The glass plate G rides on each transport roller 41 at the position of the end that does not need to be etched.
[0014]
The nozzle 5 is provided below the transfer line in the processing container 3. The etching liquid supply system 6 includes a liquid reservoir 61 for storing the etching liquid L, a pipe 62 connecting the liquid reservoir 61 and the nozzle 5, a valve 63 and a liquid pump 64 provided on the pipe 62, and the like. I have. The bottom of the processing container 3 has a funnel shape, and is provided with an etching solution collecting section 7 for collecting the used etching solution L.
[0015]
FIG. 3 is a perspective view showing the shape of the nozzle 5 shown in FIG. As shown in FIG. 3, in the present embodiment, a plurality of nozzles 5 are arranged perpendicularly to the transport direction of the glass sheet G. Each of the nozzles 5 has a tubular shape provided with an injection hole 50 at an upper portion thereof, and is provided in parallel with each other at equal intervals in a horizontal plane. Each injection hole 50 is also equally spaced in each nozzle 5.
Each injection hole 50 is elongated in a direction at an angle of 45 degrees oblique to the transport direction of the glass sheet G. Therefore, as shown in FIG. 3, the etching liquid L injected from each injection hole 50 spreads in a long inverted cone shape in this direction.
The arrangement of the injection holes 50 shown in FIG. 3 is designed so that the etching liquid L is supplied uniformly to the glass plate G. This will be described with reference to FIG. FIG. 4 is a diagram showing that each of the injection holes 50 allows the etching liquid L to be uniformly supplied to the glass plate G.
[0016]
The middle part of FIG. 4 shows the etching liquid L injected from each injection hole 50 of one nozzle 5. The lower part of FIG. 4 shows the distribution of the injection amount of the etching liquid L from each injection hole 50 as viewed in the width direction of the glass plate G. When the glass plate G passes above the nozzle 5, each point on the lower surface of the glass G receives the supply of the etching liquid L from one of the injection holes 50. At this time, at this point, the point P passing just below the intermediate position between the two adjacent injection holes 50 receives the supply of the etching liquid L from the two adjacent injection holes 50. In this case, since this point P is located at the end of the spread of the etching solution L in the reverse direction, as shown in the lower part of FIG. The etching liquid L for one injection hole 50 is supplied to the injection holes 50 on both sides, which is about の of the point. Therefore, the supply amount of the etching liquid L at each point of the glass plate G is uniform.
[0017]
In addition, a resist coating machine (not shown) is provided on the front side of the processing container 3 on the transport line. A washing machine (not shown) is provided behind the processing container 3 on the transport line. As the resist coating machine and the cleaning machine, the current one can be arbitrarily selected and adopted.
The apparatus shown in FIG. 2 includes a moving mechanism for moving the glass plate G with respect to the stationary nozzle 5 in order to uniformly supply the etching liquid L to the glass plate G. The moving mechanism is also used by the transport system 4. That is, of the transport rollers 41 constituting the transport system 4, those provided in the processing container 3 constitute a moving mechanism.
[0018]
In FIG. 2, a glass plate G having a predetermined shape on which a resist is applied in a predetermined pattern by a resist coating machine (not shown) is carried into the processing container 3 by the transport system 4. The carrier roller 41 in the processing container 3 moves the glass plate G and passes over the nozzles 5 while the etching liquid L is being sprayed from the nozzles 5. At this time, the mist-like etching solution L adheres to the lower surface of the glass plate G. Thereby, the lower surface of the glass plate G is slightly etched.
[0019]
The transport roller 41 in the processing container 3 stops the glass plate G after the glass plate G has passed above each nozzle 5, and then moves (retreats) in the opposite direction. When the glass plate G passes above the nozzles 5 again, the mist-like etching solution L adheres. Thereby, the lower surface of the glass plate G is etched a little more. The transport roller 41 in the processing container 3 passes the glass plate G above each nozzle 5, then temporarily stops, reverses, and moves again in the transport direction (moves forward). Such a reciprocating motion is repeated several times, and the mist-like etching liquid L is gradually added while being attached little by little. When the reciprocating motion is performed the number of times that the etching at a predetermined depth can be performed, the glass plate G is carried out of the processing container 3. Thereafter, the glass plate G is carried into a cleaning machine (not shown). In the cleaning machine, pure water is supplied to the surface of the glass plate G, and the remaining etching liquid L and the like are washed away. It is to be noted that the large glass plate G may be processed collectively, and then cut into individual non-fixed-side substrates 22.
[0020]
According to the mist etching method of supplying the etching liquid L in a mist state, the flatness of the etched surface is increased. As a wet etching method, a dip method in which an object is immersed in an etchant is often used. However, according to a study by the inventor, the dip method has poor flatness, and a non-fixed side substrate of a top emission type organic EL display panel is used. Cannot be used in manufacturing. According to the mist etching method in which an etching solution is sprayed and adhered by mist etching, etching with sufficiently high flatness can be performed for manufacturing a non-fixed substrate of a top emission type organic EL display panel. Note that the reason why the inner side surface of the rib 220 is tapered as described above is due to wet etching. Since wet etching proceeds isotropically, a suitable tapered surface is obtained.
[0021]
In the present embodiment, the surface to be etched of the glass plate G faces downward, and the etching liquid L is sprayed from below and adheres. This point also contributes to etching with high flatness. In the case of the type in which the liquid is ejected from above, a problem arises in the event that droplets of a certain size are discharged due to an abnormality in the pressure of the liquid sending pump 64 or the like. That is, the etching liquid adheres to the surface to be etched in the state of droplets having a certain size, and the etching proceeds abnormally much at the locations where the droplets adhere, thereby reducing the flatness. Such a problem does not occur in the case of the type in which the fuel is injected from below.
[0022]
The details of the apparatus and method according to the above configuration will be described.
The etchant is slightly different depending on the material of the glass plate G as an object, but is basically a hydrofluoric acid type. For example, those sold by Morita Chemical Co., Ltd. can be used. As the glass plate G, a so-called blue plate or white plate, soda lime glass, borosilicate glass, or the like can be considered, but all can be etched with a hydrofluoric acid-based etchant.
[0023]
The resist must have corrosion resistance to hydrofluoric acid. For example, FH-890K manufactured by Fuji Photo Film Arch Co., Ltd. can be used. For the application of the resist, a well-known method such as screen printing can be adopted.
The size of the hole of the nozzle 5 for spraying the etching liquid in a mist state is, for example, about 80 to 150 mm in width (indicated by W in FIG. 3) and about 100 to 150 mm in length (indicated by Lg in FIG. 3). Is good. The injection pressure may be about 0.15 MPa to 0.25 MPa.
[0024]
In the above embodiment, the etching liquid L is supplied uniformly while moving the glass plate G. However, the nozzle 5 may be moved in a plane parallel to the glass plate G with respect to the stationary glass plate G. Alternatively, the movement of the glass plate G and the movement of the nozzle 5 may be used in combination.
The configuration of the organic EL display includes a structure in which three color EL element portions of RGB are individually formed, a structure in which each color of RGB is emitted by a combination of a blue EL device portion and a color conversion film, and a white EL device portion. And any combination of color filters.
Further, in the above embodiment, the top emission type is adopted, but the present invention can be applied to a bottom emission type. Also in this case, the processing of the non-fixed substrate forming the package is performed not by the sandblasting method but by the wet etching method, so that there is obtained an effect that there is no problem in strength and no problem in durability.
[0025]
【The invention's effect】
As described above, according to the organic EL display panel according to the first aspect of the present invention, the processing of the non-fixed-side substrate constituting the package is performed not by the sandblast method but by the wet etching method. No sexual problems occur.
Further, according to the organic EL display panel of the second aspect, in addition to the above-mentioned effects, since it is a top emission type, the light use efficiency is high. Therefore, a bright image can be obtained with low power consumption. Further, in the non-fixed side substrate, since the concave portion having the bottom surface through which light from the EL element portion is transmitted is formed by etching performed by supplying an etching liquid in a mist state, the flatness of the concave bottom surface is reduced. Is high. For this reason, it is possible to display a high-quality image without image quality unevenness or flicker.
Further, according to the method described in claim 3 or the apparatus described in claim 5, an organic EL display panel having the effect of claim 1 can be manufactured.
According to the method described in claim 4 or the apparatus described in claim 6, an organic EL display panel having the effect of claim 2 can be manufactured.
Further, according to the apparatus of the seventh aspect, since the nozzle sprays the etching liquid from below and supplies the etching liquid to the glass plate, etching with a higher flatness can be performed. For this reason, it is possible to contribute to high-quality image display in which image quality unevenness and flicker are further reduced.
According to the eighth aspect of the present invention, since the moving mechanism for relatively moving the nozzle or the glass plate is provided, more uniform supply of the etching liquid can be performed. For this reason, it is possible to contribute to high-quality image display in which image quality unevenness and flicker are further reduced.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an organic EL display panel of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of a non-fixed-side substrate manufacturing apparatus according to the embodiment.
FIG. 3 is a perspective view showing a shape of a nozzle 5 shown in FIG.
FIG. 4 is a view showing that each of the injection holes 50 allows the etching liquid L to be uniformly supplied to the glass plate G.
FIG. 5 is a schematic sectional view of a current organic EL display panel.
FIG. 6 is a schematic cross-sectional view of a top emission type organic EL display panel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 EL element part 2 Package 21 Fixed-side substrate 22 Non-fixed-side substrate 3 Processing container 4 Transport system 41 Transport roller 5 Nozzle 50 Injection hole 6 Etchant supply system G Glass plate L Etch

Claims (8)

An organic EL display panel that emits an organic thin film by applying a voltage to the organic thin film with the pair of electrodes sandwiching the organic thin film with at least one of the electrodes being a transparent electrode,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element unit is fixed, and a non-fixed substrate on which the EL element is not fixed,
The non-fixed side substrate has a concave portion in which the EL element portion is located, and the periphery of the concave portion is a rib. The concave portion is formed by supplying the etching liquid in a mist state. An organic EL display panel formed by the following. An organic EL display panel that emits an organic thin film by applying a voltage to the organic thin film with the pair of electrodes sandwiching the organic thin film with a pair of electrodes at least one of which is a transparent electrode,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element portion is fixed, and a non-fixed substrate on which the EL element is not fixed,
The non-fixed side substrate is transparent, and is a top emission type that emits light from the EL element unit through the non-fixed side substrate,
Further, the non-fixed side substrate has a concave portion whose bottom surface is a light transmitting surface, and the peripheral edge of the concave portion is a rib, and this concave portion is formed by supplying the etching liquid in a mist state. An organic EL display panel formed by etching. A method of manufacturing a non-fixed side substrate which is a side on which an EL element portion is not fixed, of a package of an organic EL display panel containing an EL element portion inside,
A step of applying a resist on the glass plate in a predetermined pattern,
Supplying a hydrofluoric acid-based etchant in the form of a mist to the glass plate coated with the resist, and etching the fluorinated etchant to form a concave portion having a peripheral edge of a rib. Manufacturing method of side substrate. A method for manufacturing a transparent non-fixed side substrate which is a side on which an EL element portion is not fixed, of a package of a top emission type organic EL display panel containing an EL element portion therein,
A step of applying a resist on the glass plate in a predetermined pattern,
Supplying a hydrofluoric acid-based etchant in the form of a mist to the glass plate coated with the resist, and etching the fluorinated etchant to form a concave portion having a peripheral edge of a rib. Manufacturing method of side substrate. An apparatus for manufacturing a non-fixed side substrate which is a side on which an EL element portion is not fixed, of an organic EL display package containing an EL element portion therein,
A nozzle provided at a position facing the surface of the glass plate where the resist is applied and positioned at a predetermined position, and a hydrofluoric acid-based etchant is sprayed from the nozzle and supplied to the surface of the glass plate in a mist form to perform etching. With an etchant supply system,
A non-fixed-side substrate manufacturing apparatus for an organic EL display panel, wherein a concave portion having a peripheral edge as a rib is formed on a surface of a glass plate by etching. An apparatus for manufacturing a transparent non-fixed side substrate which is a side on which an EL element portion is not fixed, of a package of a top emission type organic EL display in which an EL element portion is housed,
A nozzle provided at a position facing the surface of the glass plate where the resist is applied and positioned at a predetermined position, and a hydrofluoric acid-based etchant is sprayed from the nozzle and supplied to the surface of the glass plate in a mist form to perform etching. With an etchant supply system,
A non-fixed-side substrate manufacturing apparatus for an organic EL display panel, wherein a concave portion having a peripheral edge as a rib is formed on a surface of a glass plate by etching. 7. The nozzle according to claim 5, wherein the nozzle is provided below a glass plate positioned at a predetermined position, and sprays an etchant upward to adhere to a lower surface of the glass plate to perform etching. An apparatus for manufacturing a substrate on the non-fixed side of the organic EL display panel described in the above. 8. The non-fixed side substrate of an organic EL display panel according to claim 5, further comprising a moving mechanism for relatively moving the nozzle or the glass plate and uniformly supplying an etchant. manufacturing device.

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