JP2004310063A - Exposure mask, exposure apparatus, exposure method and method for manufacturing liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure mask which makes exposure in a desired pattern possible even for a large-size object for irradiation and which is easily handled and inexpensive, and to provide an exposure apparatus, an exposure method, and a method for manufacturing a liquid crystal display using the above exposure method. <P>SOLUTION: The exposure mask has a frame 4 and a mesh material 1 fixed to the frame 4 and covering the inner region of the frame 4. The mesh material 1 has a light shielding pattern made of a resin 2, and the resin 2 is preferably a UV-curing type resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure mask, an exposure apparatus, an exposure method, and a method of manufacturing a liquid crystal display device using the above-described exposure method, for irradiating a portion of an object to be irradiated with light in a fixed shape. .

  2. Description of the Related Art Flat panel displays such as liquid crystal panels have been employed in a wide variety of devices such as mobile phones, portable information terminals, and television receivers. In these liquid crystal panels, a pair of substrates is formed so as to sandwich the liquid crystal at a predetermined interval. A substantially annular sealing material for fixing the substrates is arranged between the pair of substrates. The liquid crystal is sealed in a space surrounded by the pair of substrates and the sealing material.

  To seal the liquid crystal, a substantially annular sealing material having an injection port is formed, and two substrates are bonded together to cure the sealing material. There is a method of injecting a liquid crystal from an injection port into a space sandwiched between them and then sealing the liquid crystal. In recent years, as a method for manufacturing a liquid crystal panel, there is a manufacturing method called a drop bonding method or a drop injection method. In this manufacturing method, an annular sealing material is formed in advance on one of the pair of substrates, and a predetermined amount of liquid crystal is dropped inside the frame. This substrate is bonded to another substrate in a reduced-pressure atmosphere, and after returning to an atmosphere of atmospheric pressure, the sealing material is cured to manufacture a liquid crystal panel. By employing this method, no bubbles remain in the liquid crystal panel, and the sealing of the liquid crystal and the bonding of the substrates can be performed simultaneously.

  In any of the above methods, it is necessary to cure the sealing material after bonding the substrates together. As the sealing material, a thermosetting or ultraviolet-curing sealing material can be used. In the case of a sealing material having only thermosetting properties, a very long time is required for curing, and thus a sealing material having at least ultraviolet curability is preferably used.

In the case of irradiating ultraviolet rays to a sealing material having ultraviolet curability, if ultraviolet rays are applied to the whole of the bonded substrates, the performance of an alignment film disposed inside the substrates is reduced, or the driving element is damaged. Sometimes. Further, in the drop bonding method, the liquid crystal itself disposed inside the pair of substrates may be deteriorated. Therefore, it is preferable to irradiate the ultraviolet rays only to the place where the sealing material is arranged, and to irradiate the ultraviolet rays by arranging a mask for shielding the ultraviolet rays in the places where the irradiation is unnecessary. ).
JP 2001-235756 A (pages 6-8, FIG. 5-9)

  In recent years, with the increase in the size of the display screen, it has been required to manufacture the display panel itself in a large size. In addition, even if the display panel itself is small, it is preferable to perform so-called multi-paneling in which many patterns are formed on one large substrate and cut later, from the viewpoint of improving productivity. It is desired to use a large-sized substrate having a side of more than 1 m for a multi-panel substrate.

  Patent Document 1 discloses an exposure mask for shielding ultraviolet rays in which a light-shielding pattern is formed of an aluminum film on a main surface of a quartz substrate. Alternatively, as the same exposure mask, there is a mask in which a chromium film is formed on a quartz substrate.

  However, these conventional exposure masks are very expensive because the material itself, such as quartz, is expensive, and the formation of a light-shielding pattern also requires time and effort. Further, as the size of the display panel to be manufactured increases, the size of the exposure mask also increases. As a result, it becomes very heavy, and it is difficult to handle, for example, requiring a lot of manpower when moving. To increase the size of the exposure mask, it is conceivable to reduce the thickness of the exposure mask. However, when the thickness of the quartz substrate is reduced, the exposure mask bends due to its own weight when installed in an exposure apparatus, so that a desired position cannot be shielded (exposed). was there.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and it is possible to perform exposure to a desired shape even for a large object to be irradiated, and is easy to handle and inexpensive. It is an object to provide a mask, an exposure apparatus, an exposure method, and a method for manufacturing a liquid crystal display device using the above exposure method.

  In order to achieve the above object, an exposure mask according to the present invention includes a frame and a mesh material fixed to the frame so as to cover a region inside the frame. A light-shielding pattern is formed of a resin on the mesh material. By employing this configuration, exposure can be performed in a desired shape even on a large object to be irradiated. Further, it is possible to provide an inexpensive exposure mask which is easy to handle.

  Preferably, in the above invention, the mesh material includes a metal wire. By employing this configuration, the exposure mask can be used even for exposure in which the temperature of the mesh material increases. Further, the reflectance of the surface of the mesh material can be increased, and the light reflected on the surface of the mesh material can be efficiently applied to the irradiation object.

  In the above invention, preferably, the resin is a resin having ultraviolet curability. By employing this configuration, the light-shielding pattern can be easily formed even if the light-shielding pattern has a complicated shape or the exposure mask has a large size.

  In the above invention, preferably, the opening is formed so that a portion to be changed when viewed from directly above is accommodated therein. By employing this configuration, it is possible to reliably perform exposure on a portion where the above change is to occur. Also, exposure can be performed on the side surface of the portion where the above change is to occur.

  In order to achieve the above object, an exposure apparatus according to the present invention includes a holding unit for holding an object to be irradiated, and a light source for irradiating a portion of the object to be irradiated with light. Further, an exposure mask is provided between the position where the object to be irradiated is held and the light source, and has a light shielding pattern formed of a resin on a mesh material. By employing this configuration, it is possible to perform exposure to a desired shape even on the large object to be irradiated. Further, the exposure mask can be easily handled, and an inexpensive exposure apparatus can be provided.

  In the above invention, preferably, a reflection plate is provided around a space between the light source and the position where the irradiation object is held. By adopting this configuration, it is possible to reflect the light directed to the side of the exposure apparatus by the reflecting plate and irradiate the object to be irradiated. Further, the object to be irradiated can be exposed from directions other than the direction in which the light source is arranged.

  In order to achieve the above object, an exposure method according to the present invention is a method of performing exposure by disposing an exposure mask between a light source and an object to be irradiated. Is used in which a light shielding pattern is formed. By employing this method, it is possible to perform exposure to a desired shape even on the large object to be irradiated. Further, the exposure mask can be easily handled, and the exposure can be performed at low cost.

  In the above invention, preferably, the mesh material is formed of a metal wire. By employing this method, the above-described exposure method can be used even in the exposure in which the mesh material has a high temperature.

  In the above invention, preferably, a resin having ultraviolet curability is used as the resin. By employing this method, the light-shielding pattern can be easily formed even if the light-shielding pattern is complicated or large.

  In the above invention, preferably, an ultraviolet lamp is used as the light source. By employing this method, the above-described exposure method can be applied to an exposure method for curing an ultraviolet curable resin.

  In order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention includes a step of stacking two substrates so as to sandwich a sealing material, and an exposure mask in which a light shielding pattern is formed of resin on a mesh material. Curing the sealing material by exposing the substrate between the two stacked substrates and the light source and performing exposure. By employing this method, the sealing material having a desired shape can be cured even for a large display panel. Further, the sealing material can be cured at low cost.

  An exposure mask, an exposure apparatus, an exposure method, and a method for manufacturing a liquid crystal display device, which can perform exposure to a desired shape even on a large irradiation object and are easy to handle, can be provided.

(Embodiment 1)
(Constitution)
An exposure mask and an exposure method according to a first embodiment of the present invention will be described with reference to FIG.

  1A and 1B are explanatory views of an exposure mask according to the present embodiment, wherein FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. In the exposure mask according to the present invention, an annular frame 4 is formed as a frame. The frame 4 in the present embodiment is formed of aluminum, and is formed such that its outer dimensions are 1450 mm long, 1730 mm wide, 50 mm thick, and 50 mm wide. The mesh material 1 is adhered and fixed to one surface of the frame 4 so as to cover the area inside the frame 4 with tension. The mesh material 1 is formed using a stainless steel wire as a material. As the wire in the present embodiment, a wire having a diameter of 0.058 mm is used. The mesh material 1 has a mesh shape of a square.

  On the main surface of the mesh material 1, a resin 2 is disposed, and a light-shielding pattern having an opening 3 is formed. As the resin 2, a resin having ultraviolet curability is used, and is formed so as to have a thickness of 1 mm. The opening 3 is a region where the resin is not arranged. In the present embodiment, the inner and outer peripheries of the planar shape are rectangular, and six frame-shaped openings 3 whose inner and outer peripheries are substantially parallel to each other are formed. The opening 3 is formed along the plane shape of the region to be irradiated with ultraviolet rays. That is, the planar shape of the portion in the present embodiment where the object to be irradiated is to be changed is also a frame shape.

  In this embodiment, an exposure mask in which the frame is made of aluminum and the mesh material is made of stainless steel has been described. However, the present invention is not particularly limited to this. The mesh material may be nickel, polyester, nylon, plastic, or glass fiber. And so on. The frame is not limited to metal, but may be plastic or the like. As the frame, it is preferable to use a material having a strength that does not deform even with the tension of the mesh material, or to be formed to have a thickness that does not deform. The shape of the frame is not limited to an annular shape, and may be, for example, a so-called U-shaped shape in which one side of a square is removed. Also, the shape of the mesh of the mesh material 1 is not limited to a square. Further, as the resin for forming the light-shielding pattern, a resin having both UV-curing and thermosetting properties may be used. In this case, curing by heating may be performed after curing by UV irradiation.

(Action / Effect)
As shown in FIG. 1B, for example, when exposure is performed in a direction indicated by an arrow 33, light is blocked in a region where the resin 2 is formed, and light entering the region of the opening 3 is blocked. Only the light passes through the exposure mask as shown by arrow 34. In this manner, light can be applied only to the shape of the region of the opening 3. The exposure mask in this embodiment is formed so that light can be irradiated in a frame shape.

  The exposure mask in the present embodiment is formed from an annular frame, a mesh material, and a resin that forms a light-shielding pattern. By adopting this configuration, it is possible to significantly reduce the weight compared with the exposure mask according to the conventional technique, and the handling is easy even when the mask is moved. Further, by using a mesh material and a resin, an exposure mask can be formed at low cost. Further, even if the exposure mask is large, the shape of the region to be exposed is not deformed by bending of the exposure mask, and the exposure can be performed in a desired shape. In particular, by joining the mesh member to the frame while applying an appropriate tension, it is possible to prevent the mesh member from bending.

  In the method of manufacturing an exposure mask according to the present embodiment, first, a mesh material is attached to an annular frame, and an ultraviolet curable resin is applied to the entire surface of the mesh material. Thereafter, patterning of the ultraviolet curing resin is performed by a photolithography method. By patterning the ultraviolet curable resin, an opening through which light passes is formed.

  In the present embodiment, as described above, the ultraviolet curable resin is used for the light-shielding pattern. However, the present invention is not particularly limited to this mode, and a metal plate such as stainless steel, nickel, or cobalt may be used as the light-shielding pattern. When the light-shielding patterns of these metal plates are attached to the mesh material, for example, an ultraviolet-curable resin is used. The surface on which the metal plate is to be attached may be any of the front and back surfaces of the mesh material.

  By including the metal wire as the mesh material, it can be used for light irradiation that raises the temperature of the exposure mask. For example, the temperature of the exposure mask increases when ultraviolet irradiation is performed. Therefore, it is preferable to use a heat-resistant mesh material as in this embodiment mode. Further, by including the metal wire as the mesh material, a part of the light reflected on the surface of the metal wire can be applied to the irradiation object. Therefore, it is preferable that the mesh material is formed of a material having a high reflectance such as a metal wire.

  The wires constituting the mesh material are preferably as thin as possible in consideration of increasing the aperture ratio and transmitting a large amount of light. Similarly, in order to increase the aperture ratio, the mesh material preferably has a coarse mesh. However, if the wire of the mesh material is too thin or the roughness of the mesh is too rough, it becomes difficult to arrange the resin on the main surface of the mesh material. It is preferable to change one size or the thickness of the wire of the mesh material.

  By forming the light-shielding pattern with a resin, the weight of the exposure mask can be reduced as compared with a light-shielding pattern of a metal film or the like. As the resin, it is preferable to select a resin having a strong light-shielding property with respect to irradiation light. Alternatively, it is preferable that the thickness be large enough not to transmit light. Also, by using a photosensitive resin such as a resin having ultraviolet curability as a resin, a complicated light-shielding pattern can be easily formed. Further, even with a large exposure mask, a light-shielding pattern can be easily formed.

  The exposure mask according to the present invention can be used for exposure where a mask is required for a part of an irradiation object. For example, it can be used in a process of manufacturing a resin part having a certain shape by exposing a photosensitive resin to cure only a part thereof.

(Embodiment 2)
With reference to FIGS. 2 and 3, an exposure mask, an exposure method, and a method for manufacturing a liquid crystal display device according to the present invention will be described.

  FIG. 2 is an explanatory diagram of a step of fixing two substrates with a sealing material in the method of manufacturing a liquid crystal display device. In this embodiment mode, a glass substrate is used as a substrate. In this embodiment, a glass substrate having a length of 1200 mm, a width of 1500 mm, and a thickness of 0.7 mm is used.

  FIG. 2A is a cross-sectional view when a sealing material of the liquid crystal display device is being exposed. As described above, the liquid crystal display device has a configuration in which liquid crystal is sealed between the substrates. In the drop-injection method, a sealing material is formed in a frame shape on the main surface of one substrate in advance, and an appropriate amount of liquid crystal is placed on one of the substrates so as to be positioned inside the frame shape when two substrates are stacked. Then, the substrates are stacked so as to sandwich the sealing material. As a result, as shown in FIG. 2A, the liquid crystal 12 and the sealing material 11 are sandwiched between the substrates 10a and 10b. The sealing material 11 is a partition for enclosing the liquid crystal. The distance between the substrates is made constant by a spacer (not shown). In the present embodiment, the distance between the substrates is 2 μm to 5 μm.

  The sealing material 11 is formed of a resin having an ultraviolet curing property. In FIG. 2A, the sealing material 11 is cured by irradiating the sealing material 11 with ultraviolet rays. As the exposure mask, the exposure mask in Embodiment 1 is used. That is, the light-exposure mask has a light-shielding pattern formed of a resin on a mesh material, and the opening 3 has a frame shape in which the inner and outer circumferences are rectangular and the inner and outer circumferences are substantially parallel to each other. It has become. Note that a resin having both UV-curing properties and thermosetting properties may be used as the sealing material 11, and in that case, curing by heating may be performed after curing by UV irradiation.

  As a light source, an ultraviolet lamp (length: 2000 mm, diameter: 50 mm) is used, and ultraviolet light from the light source is irradiated as shown by an arrow 30. The irradiation amount of the ultraviolet light in the present embodiment is 1 to 3J. The opening 3 is formed corresponding to the position where the sealing material 11 is arranged. The distance between the irradiation target and the exposure mask is 1 mm. Ultraviolet rays pass through the region of the opening 3 and are irradiated on the sealing material 11 to cure the sealing material 11. Thus, the present invention can be applied to an exposure method for curing a resin having ultraviolet curability by using an ultraviolet lamp as a light source.

  In the substrates 10a and 10b, an alignment film is formed on a surface where the substrates face each other. Further, a TFT (Thin Film Transistor) element, a signal line, and the like are formed in a display area (active area) of one substrate and the periphery thereof, and a driving element and the like are formed outside the sealing material 11 ( Not shown). A light-shielding pattern is formed in areas other than the area directly above the area where the sealing material 11 is formed so that ultraviolet rays are not irradiated to these parts as much as possible. The resin 2 arranged as a light-shielding pattern is formed of a resin having a low transmittance of ultraviolet rays.

  As described above, by using a mask having a light-shielding pattern formed of a resin on a mesh material between a light source and an irradiation target as an exposure mask, an accurate position and position can be obtained even for a large irradiation target. Exposure can be performed in the shape. In addition, handling is easy, and exposure can be performed at low cost. In addition, by curing the sealing material by the above-described exposure method, it is possible to provide a method of manufacturing an inexpensive liquid crystal display device with improved yield and improved workability.

  The effects and effects of using a metal wire formed as a mesh material or using a resin having ultraviolet curability as the resin of the light-shielding pattern are the same as those of the exposure mask of the first embodiment. Since it is similar, the description will not be repeated here.

  FIG. 2B is an explanatory diagram of the size of the opening 3 of the exposure mask. The opening 3 is disposed directly above the sealing material 11 which is a part to be changed, and FIG. 2B is a view when the opening 3 is viewed from directly above. The opening width 15 of the opening 3 is formed to be larger than the seal width 16 which is the width of the sealing material 11. In this manner, when the opening to be changed is formed such that the portion to be changed is accommodated inside when viewed from directly above, the portion to be changed can be surely irradiated with light. In addition, when the sealing material is cured as in the present embodiment, not only the upper surface but also the side surface of the sealing material can be exposed, and the sealing material 11 can be efficiently cured. Can be. In particular, since the mesh material is formed of the metal wire, a part of the light reflected on the surface of the metal wire can be applied to the side surface of the sealing material.

  In the manufacturing method of the liquid crystal display device, as described above, the liquid crystal may be injected into a region surrounded by the substrate and the sealing material after the two substrates are completely fixed with the sealing material so as to be stacked first. When irradiating with ultraviolet rays in this manufacturing method, the ultraviolet rays are radiated with no liquid crystal arranged inside. However, an exposure mask is required for reasons such as protection of the alignment film. FIG. 3 shows a plan view of an exposure mask in this manufacturing method. The shape of the sealing material is a shape having an injection port in a part of the frame shape. The opening 3 of the exposure mask is formed in a frame shape having a rectangular inner periphery and outer periphery along the above-described injection port in accordance with this shape. Other configurations, operations, and effects are the same as those of the exposure mask shown in FIG. 1 in the first embodiment, and thus description thereof will not be repeated.

(Embodiment 3)
(Constitution)
An exposure apparatus according to the third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic sectional view of the exposure apparatus. An exposure apparatus for curing the sealing material of the liquid crystal display device described in Embodiment 2 will be described.

  A plurality of ultraviolet lamps 22 as light sources are arranged on the upper part of the exposure apparatus. On the opposite side of each of the ultraviolet lamps 22 on which the object is arranged, an ultraviolet ray is directed toward the object. A reflection plate 23b for reflecting light is formed. The reflection plate 23b is formed so that its cross section has an arc shape.

  A suction stage 25 is formed below the exposure apparatus as holding means for holding an object to be irradiated. The suction stage 25 is formed so that an object to be irradiated can be held by vacuum suction. When a suction stage is formed as the holding means, the suction stage 25 is formed so as to have the same size as the substrate 10b to be sucked or larger than the size of the substrate 10b. A liquid crystal display panel as an object to be irradiated has a liquid crystal 12 arranged between two substrates 10a and 10b. The sealing material 11 is the one before curing.

  On both sides of the suction stage 25, mask support portions 24 for holding the exposure mask 35 are formed. The mask support 24 is formed so as to support the exposure mask so as to separate the position where the irradiation target is held from the ultraviolet lamp 22. In the present embodiment, the mask support 24 is formed on the side of the exposure apparatus. The exposure mask 35 is supported such that the main surface of the substrate 10a and the main surface of the exposure mask 35 are parallel. The exposure mask 35 is formed so as to allow ultraviolet rays to pass through the region of the sealant 11, and is fixed to the mask support portion 24 by positioning the opening 3. As the exposure mask 35, a mask having a light shielding pattern formed of resin on the mesh material shown in FIG. 1 is used.

  A reflector 23a is formed around a space between the position of the liquid crystal display panel held on the upper surface of the suction stage 25 and the ultraviolet lamp 22. In the present embodiment, a plate-like reflecting plate 23a for reflecting ultraviolet light is formed above the mask supporting portion 24. The reflection plate 23a is not limited to the planar shape as shown in FIG. 4, but may be a curved shape such as a circular cross section.

(Action / Effect)
The ultraviolet rays are emitted isotropically in the radial direction of the ultraviolet lamp, but the upwardly directed ultraviolet rays are reflected on the surface of the reflector 23b. Therefore, most of the ultraviolet rays are directed downward, that is, in the direction of the irradiation target, as indicated by the arrow 31. The emitted ultraviolet light is applied to the sealing material 11 through the opening 3 of the exposure mask.

  As described above, by employing an exposure apparatus including an exposure mask in which a light-shielding pattern is formed of a resin on a mesh material, a holding unit for an object to be irradiated, and a light source, even a relatively large substrate can be used. Can be exposed. Even when the exposure pattern needs to be changed, the exposure mask can be easily changed, that is, the exposure mask can be easily replaced because the exposure mask is lightweight.

  Some of the light emitted from the light source is directed to the side of the exposure apparatus. However, a reflector 23a is formed around a space between the position where the object to be irradiated is held and the ultraviolet lamp 22. As a result, as shown by the arrow 32, the light can be reflected by the reflection plate 23a and collected in the direction of the irradiation object. In particular, with respect to a liquid crystal display device manufacturing apparatus, the provision of the reflection plate 23a allows light to be incident on the main surface of the exposure mask 35 from the side. By the reflection on the surface of the metal wire, the side of the sealing material 11 can be irradiated with ultraviolet rays.

  In the present embodiment, an exposure apparatus in a manufacturing process of a liquid crystal display device has been mainly described. However, the present invention is not limited to this exposure apparatus and can be applied to any apparatus that performs exposure through a mask.

  Note that the above-described embodiment disclosed this time is illustrative in all aspects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an exposure mask according to a first embodiment of the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along line IB-IB in (a). FIGS. 7A and 7B are explanatory views of an exposure method and a method of manufacturing a liquid crystal display device according to a second embodiment of the present invention, wherein FIG. FIG. 13 is a plan view of an exposure mask according to a second embodiment of the present invention. FIG. 13 is a schematic sectional view of an exposure apparatus according to a third embodiment of the present invention.

Explanation of reference numerals

  Reference Signs List 1 mesh material, 2 resin, 3 opening, 4 frame, 10a, 10b substrate, 11 sealant, 12 liquid crystal, 15 opening width, 16 seal width, 22 ultraviolet lamp, 23a, 23b reflector, 24 mask support, 25 Suction stage, 30, 31, 32, 33, 34 arrows, 35 Exposure mask.

Claims (11)

Frame and
An exposure mask, comprising: a mesh material fixed to the frame so as to cover an area inside the frame, wherein a light-shielding pattern is formed of resin on the mesh material.   The exposure mask according to claim 1, wherein the mesh material includes a metal wire.   The exposure mask according to claim 1, wherein the resin is a resin having ultraviolet curability.   2. The exposure mask according to claim 1, wherein the opening is formed such that a portion to be changed when viewed from directly above is accommodated therein. Holding means for holding the irradiation object,
A light source for irradiating a portion of the object to be irradiated with light,
An exposure apparatus, comprising: an exposure mask disposed between a position where the object to be irradiated is held and the light source and having a light shielding pattern formed of a resin on a mesh material.   The exposure apparatus according to claim 5, further comprising a reflector around a space between the light source and a position where the object is held. A method of arranging an exposure mask between a light source and an irradiation object to perform exposure,
An exposure method, wherein a mask having a light shielding pattern formed of resin on a mesh material is used as the exposure mask.   The exposure method according to claim 7, wherein a material formed of a metal wire is used as the mesh material.   The exposure method according to claim 7, wherein a resin having ultraviolet curability is used as the resin.   The exposure method according to claim 7, wherein an ultraviolet lamp is used as the light source. A step of stacking two substrates so as to sandwich the sealing material,
Exposing an exposure mask in which a light-shielding pattern is formed of a resin on a mesh material, disposing the exposure mask between the two substrates and a light source, and curing the sealing material. A method for manufacturing a liquid crystal display device.

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