JP3663448B2 - Coating equipment using capillary action - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, the coating liquid is applied to a plate-like base material such as a glass substrate, a dry plate or a metal plate, or a long and flexible base material (web) such as a plastic film, a metal foil, a fabric or a non-woven fabric. The present invention relates to a coating apparatus and a nozzle used therefor. In particular, the present invention relates to a coating apparatus and a nozzle that use capillary action.
[0002]
[Prior art]
In the field of semiconductors and flat display devices, spin coating or the like has been a common technique for forming a uniform film for forming a protective film on a substrate.
[0003]
However, in the case of spin coating, there are problems such as formation of raised portions at the edge of the substrate and splashing of the coating liquid. In addition, there is a problem that the coating cannot be performed only on a predetermined area of the substrate, and there are many wasteful coating liquids, so that the cost cannot be reduced.
[0004]
Therefore, in recent years, coating apparatuses that perform application using capillary action have been proposed (Japanese Patent Laid-Open Nos. 8-22528 and 6-43908). In such a coating apparatus, the nozzle extending linearly in the coating width direction is provided with a slit-shaped coating liquid rising path that guides the coating liquid to the nozzle outlet by capillary action, and is positioned above. A coating solution is applied to the lower surface of the substrate to be processed.
[0005]
Specifically, the nozzle is submerged in a liquid reservoir tank with a lid extending linearly in the coating width direction, and when coating is performed, the lid is opened and the nozzle is raised so that the discharge port at the upper end of the nozzle is upward. So that it is placed close to the bottom surface of the substrate. Then, the meniscus on the nozzle discharge port is brought into contact (wetted) with the lower surface of the substrate to perform coating.
[0006]
In such a method, the coating liquid is supplied to the discharge port by capillary action only through one slit-shaped coating liquid rising path.
[0007]
[Problems to be solved by the invention]
Therefore, although it is suitable for coating a thin film having a considerably small thickness, the coating thickness cannot be increased beyond a certain limit. Although the supply amount of the coating liquid can be increased within a certain range by adjusting the slit width of the coating liquid rising path, the slit width is made larger than a predetermined width because of the capillary phenomenon. Then, the supply amount of the coating liquid is reduced.
[0008]
For the purpose of increasing the coating thickness, it was considered to adjust the coating speed or increase the concentration of the coating solution, but even if the concentration was increased, the supply amount decreased due to the increase in viscosity. For the reason, there were many cases where almost no effect was obtained.
[0009]
In addition, it was considered that the height of the coating liquid rising from the liquid surface of the liquid reservoir tank to the discharge port of the nozzle tip was reduced, and that the gap between the nozzle tip and the substrate was reduced, Even if these were optimized, the coating thickness could not be increased so much.
[0010]
The present invention has been made in view of the above problems, and in a coating apparatus that guides a coating liquid from a reservoir tank to the tip of a nozzle by capillary action, it is possible to realize an increase in coating thickness or an improvement in coating processing efficiency. A construction device is provided.
[0011]
[Means for Solving the Problems]
The coating apparatus according to claim 1 is arranged to extend in the left-right direction so as to apply the coating liquid to the substrate moving in the front-rear direction, and the coating liquid ascending path guides the coating liquid to the discharge port by capillary action. And a liquid storage tank that stores the nozzle and supplies the coating liquid to the lower part of the coating liquid ascending path. A capillary phenomenon promoting member that promotes capillary action is provided.
[0012]
With the above configuration, it is possible to increase the supply amount of the coating liquid to the base material, and it is possible to increase the coating thickness.
[0013]
The coating apparatus according to claim 2 is arranged to extend in the left-right direction so as to apply the coating liquid to the web moving in the front-rear direction, and the coating liquid ascending path guides the coating liquid to the discharge port by capillary action. And a liquid storage tank that stores the nozzle and supplies the coating liquid to the lower part of the coating liquid ascending path. A capillary phenomenon promoting member that promotes capillary action is provided.
[0014]
In the coating apparatus according to claim 4, the partition wall as the capillary phenomenon promoting member is a flat plate extending in the left-right direction, and the coating liquid rising path is composed of two or more slit-shaped paths. To do.
[0015]
With such a configuration, the supply amount of the coating liquid can be greatly increased only by adding a simple structural member.
[0016]
The coating apparatus according to claim 5 is characterized in that the flat plate forming the partition wall and the spacer plate are held between a pair of basic members constituting the nozzle.
[0017]
With such a configuration, the position can be freely changed to the closed region on the discharge port, and the application width can be easily changed.
[0018]
The coating apparatus according to any one of claims 7 to 8, wherein the coating device is arranged so as to extend in the left-right direction so as to apply the coating liquid to the lower surface of the plate-like or elongate substrate moving in the front-rear direction, and is applied by capillary action. In a coating apparatus comprising a nozzle having a coating liquid ascending path for guiding a working liquid to a discharge port, and a liquid reservoir tank for storing the nozzle and supplying the coating liquid to a lower part of the coating liquid ascending path The plurality of nozzles are arranged side by side in the front-rear direction, and after the application by one of the nozzles, the application is further performed by the other nozzles to perform overcoating on the substrate.
[0019]
Also with the above configuration, it is possible to increase the supply amount of the coating liquid to the base material and realize an increase in the coating thickness.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
<First embodiment>
A first embodiment of the present invention will be described with reference to FIGS.
[0021]
FIG. 1 is a cut perspective view schematically showing the main part of the coating apparatus and the state of application to the lower surface of the glass substrate 28. Here, the glass substrate 28 is used for a display panel or the like of a liquid crystal display device, and the coating liquid is for forming a protective film, for example.
[0022]
The nozzle 82 extending linearly in the coating width direction sequentially supplies the coating solution to the lower surface of the glass substrate 28 that moves substantially horizontally in the central coating region. That is, as the glass substrate 28 moves, the coating liquid that wets the glass substrate 28 is sequentially lifted from the discharge port 83 at the tip of the nozzle 82 to the lower surface of the glass substrate 28 by the surface tension of the coating liquid. Done.
[0023]
The nozzle 82 has a beak-shaped discharge port 83 projecting upward from a substantially rectangular or substantially trapezoidal main body portion in a cross section (application direction cross section), and extends vertically from the lower surface to the discharge port 83. A coating liquid rising path 88 is formed. As shown in the cross section, the coating liquid ascending path 88 is divided by a flat partition plate 85 to form a multilayer slit. In the illustrated example, three partition plates 85 are sandwiched between a pair of nozzle basic members 86 constituting the nozzle 82 via a spacer plate 87 to form four layers of slit-shaped paths 88-1 to 88-4. ing. These partition plates 85 are arranged vertically, and are arranged in parallel with the inner side surface of the nozzle basic member 86, that is, the vertical wall surface facing the coating liquid ascending path 88.
[0024]
The nozzle 82 is accommodated in the liquid reservoir tank 66, and when performing application, the nozzle 82 is submerged in the coating liquid stored in the liquid reservoir tank 66 except for the portion of the discharge port 83.
[0025]
As shown in the figure, the liquid storage tank 66 has a cross-sectional shape in which the alphabet C is tilted to the left, and when performing application, from the upper slit-shaped opening 84, the discharge port 83 of the nozzle 82 is provided. Protrudes upward. Here, the height of the liquid level in the liquid reservoir 66 is maintained at a predetermined height by a liquid level adjustment mechanism described later. Further, the height positions of the nozzle 82 and the liquid reservoir tank 66 are also maintained at predetermined values by a vertical movement / support mechanism described later.
[0026]
At both ends of the nozzle 82 in the application width direction, the members 85 to 87 constituting the nozzle 82 are screwed with screws 89. The nozzle 82 is supported at both ends by a nozzle support shaft 78 and is moved up and down via the nozzle support shaft 78 as will be described later. The upper end portion of the nozzle support shaft 78 passes through the bottom surface of the liquid reservoir tank 66, and a bellows-like boot (closing member) 98 having a mouth portion joined to the opening of the bottom surface is arranged to leak the coating liquid. Protrusion is prevented.
[0027]
Note that the application region 83 a on which the application is performed on the discharge port 83 is sandwiched from both sides in the application width direction by the closed region 83 b where the discharge port 83 is closed by the spacer plate 87. In the region 83c outside the closed region 83b, a meniscus 90a of the coating liquid 90 is formed as shown in the figure.
[0028]
The three partition plates 85 are provided with screw through holes at both ends, and are fixed by screws 89 between the pair of nozzle basic members 86. At this time, the spacer plate 87 is sandwiched between the partition plates 85 and between the partition plate 85 and the nozzle basic member 86 at the location where the pair of closed regions 83b are formed. Therefore, for example, a total of eight spacer plates 87 are sandwiched between the nozzles 82, four on each side.
[0029]
At the lower end portion of the nozzle 82, a coating liquid introduction portion having a trumpet cross section opened downward from the lower ends of the slit-shaped paths 88-1 to 88-1 is formed. That is, each nozzle basic member 86 is formed with an inclined surface 86b at a location desired for the coating liquid introducing portion at the lower end of the inner surface.
[0030]
In the case of the nozzle of this embodiment, as described above, the coating liquid rising path 88 is formed as a multilayer slit, and each partition wall 85 contributes to pulling up the coating liquid 90 by capillary action. Compared with the prior art using a single-layer slit, a larger amount of coating liquid can be supplied.
[0031]
That is, the coating thickness is increased by the number of the slit-shaped paths 88-1 to 88-4 as compared with the conventional case.
[0032]
The nozzle basic member 86 and the partition plate 85 are made of stainless steel in a specific example. However, the nozzle basic member 86 and the partition plate 85 are made of other metals, plastics, etc. as long as they are materials that have good wettability to the coating liquid and cause sufficient capillary action. But it ’s okay.
[0033]
According to the above embodiment, even if the supply amount of the coating liquid is increased in this way, the only members to be added are the partition plate 85 and the spacer plate 87 having a simple structure, and the assembling work is easy. In particular, the position of the closed region 83b can be easily changed simply by changing the position where the spacer plate 87 is disposed. Therefore, it is possible to easily set and change the coating width.
[0034]
Further, by providing the closed regions 83b in which the discharge ports 83 are closed on both sides of the application region 83a as described above, it is possible to effectively prevent changes in the application thickness at both ends of the application region 83a. When the closed region 83b is not provided, the coating solution is drawn from the meniscus 90a of the coating solution in the region 83c outside the coating width to both ends of the coating width on the lower surface of the glass substrate 28, or the meniscus Since the surface tension from 90a acts, the coating thickness changes at both ends of the coating width and in the vicinity thereof.
[0035]
Next, a support / drive mechanism that supports the nozzle 82 and moves up and down and a support / drive mechanism that supports and moves the liquid reservoir 66 up and down will be briefly described with reference to FIGS.
[0036]
A liquid storage tank 66 is supported from the base plate 32 via a liquid storage tank support member 54 having an L-shaped cross section and single wedge-shaped movable cotters 34 and 36.
[0037]
The liquid storage tank support member 54 has a vertical plate 56 with a liquid storage tank 66 fixed to the upper end, a horizontal plate 58 connected to the lower end of the vertical plate 56, and protrudes downward from the center of the horizontal plate 58, and extends from the base plate. A guide shaft receiving portion 65 that receives the guide shaft 64 and leg portions 60 and 62 that protrude downward from the horizontal plate 58 on both sides of the guide shaft receiving portion 65.
[0038]
The movable cotters 34, 36 have slide-like slopes on which the legs 60, 62 of the liquid reservoir support member 54 are placed, and are driven in the coating width direction by the servo motor 52 and the ball screw 50. . That is, when the movable cotters 34 and 36 are driven in the coating width direction, the liquid reservoir support member 54 is precisely moved up and down. At this time, the horizontal displacement of the liquid reservoir support member 54 is prevented by the guide shaft 64 and the guide shaft receiving portion 65.
[0039]
Linear ways 42 and 48 are formed between the leg portions 60 and 62 and the movable cotters 34 and 36, and linear ways 38 and 44 are similarly provided between the movable cotters 34 and 36 and the base plate 32. Is formed.
[0040]
On the other hand, the nozzle support shafts 78 and 80 that support both ends of the nozzle 82 are supported from the liquid reservoir support member 54 via the vertical movable plate 74 and the horizontal movable plate 70.
[0041]
A guide shaft receiving portion 75 for receiving a guide shaft 76 protruding upward from the horizontal plate 58 of the liquid reservoir supporting member 54 is joined to the vertically movable plate 74 that supports the liquid reservoir supporting member 54. Thereby, the horizontal displacement of the vertical movable plate 74 is prevented.
[0042]
The horizontal movable plate 70 is supported from the vertical plate 56 of the liquid reservoir support member 54 via a pair of linear ways 68 arranged in the horizontal direction, and is driven in the coating width direction by the air cylinder 71.
[0043]
The upper and lower movable plates 74 that support the liquid reservoir support member 54 are supported from the horizontal movable plate 70 via a pair of linear ways 72 that are diagonally disposed so as to descend to one side, and the horizontal movable plate 70 is driven in the horizontal direction. As it is done, it is driven up and down. In this way, the nozzle 82 is driven up and down via the horizontal driving of the horizontal movable plate 70 in accordance with the driving of the air cylinder 71.
[0044]
The glass substrate 28 is supported by a suction table 24 equipped with a suction mechanism and moved at a predetermined speed. The suction table 24 and other components, and the detailed coating process are the same as in Japanese Patent Application No. 11-245497.
[0045]
FIG. 3 shows a liquid level detection tube 112 protruding from the liquid storage tank 66 in a horn shape. This is described in detail in Japanese Patent Application No. 11-245497. For controlling the supply amount of the coating liquid from the coating liquid tank to the liquid storage tank 66 by the pump. Due to the balance between the drain pipe from the liquid storage tank 66 and the supply amount of the coating liquid, the liquid level of the liquid storage tank 66 is maintained at a predetermined value.
[0046]
With the above vertical movement / support mechanism, precise vertical movement and setting of the height position can be realized with a simple structure.
[0047]
<Second embodiment>
Next, the coating apparatus of the second embodiment will be described with reference to the schematic sectional view of FIG.
[0048]
In this embodiment, as shown in FIG. 4, the single-layer slit nozzles 82 ′ similar to those in the prior art are provided twice, and two nozzles 82 ′-1, 82 ′- Application is performed almost continuously from 2. That is, the two nozzles 82′-1 and 82′-2 are arranged side by side so as to overlap in the application direction, and after the application by the first nozzle 82′-1, the second nozzle 82 ′ is further added. Overcoating is performed by applying by -2.
[0049]
Therefore, as in the case of the above embodiment, compared to the case of using a capillary phenomenon type coating nozzle of the prior art, it is possible to increase the supply amount of coating liquid per unit time, and to realize an increase in coating thickness. Can do.
[0050]
Also in this embodiment, it is possible to prevent the change in the coating thickness at both ends of the coating region by providing the blocking regions 83b by the spacer plate 87 or the like on both sides of the coating region 83a. Further, the vertical movement drive mechanism can be used to perform accurate and reliable vertical movement.
[0051]
<Modifications 1 to 16>
Next, the nozzles of modified examples 1 to 16 will be described with reference to FIG. In these modifications, various changes are made to the configuration of the coating liquid rising path 88 in the first embodiment.
[0052]
In Modification 1 (1), vertical round bars having a diameter equal to the width of the slit-like path are closely arranged in the slit-like path between the pair of nozzle basic members 86. That is, a small capillary coating liquid rising path is formed between the adjacent round bars and the flat wall of the nozzle basic member 86.
[0053]
In the modified example 2 (2), the round bar of the modified example 1 is replaced with a hollow cylindrical pipe, and the space in the pipe also forms a capillary-like minute coating liquid rising path.
[0054]
In the modified example 3 (3), a plate in which a large number of vertical grooves (vertical grooves) are closely arranged on one side is sandwiched between a pair of nozzle basic members 86. It forms a capillary-like minute coating liquid rising path.
[0055]
In the modified examples 4 to 5 (4 to 5), a plate in which a large number of vertical through holes (longitudinal holes) are closely arranged is sandwiched between a pair of nozzle basic members 86, and the large number of the vertical holes are respectively hairs. It forms a small tubular coating liquid rising path. In the fourth modification, the cross section of the vertical hole is rectangular (square), whereas in the fifth modification, the cross section of the vertical hole has a substantially elliptical diameter.
[0056]
In Modification 6 (6), a plate made of a porous metal sintered body is sandwiched between a pair of nozzle basic members 86. Complex continuous voids in the metal sintered body form a large number of capillary microscopic coating liquid rising paths.
[0057]
In the modified example 7 (7), a plate whose horizontal cross section has a pulse wave shape, that is, a plate in which a large number of vertical grooves (vertical grooves) are closely arranged on both sides is sandwiched between a pair of nozzle basic members 86. In many cases, the large number of vertical grooves each form a capillary-shaped minute coating liquid rising path.
[0058]
In the modified example 8 (8), a large number of vertical round bars whose diameters are smaller than the interval between the slits are closely arranged in the slit-like path between the pair of nozzle basic members 86. As a result, a large number of capillary microscopic coating liquid rising paths are formed between the round bars or between the round bars and the flat wall of the nozzle basic member 86.
[0059]
In the modified example 9 (9), the round bar of the modified example 8 is replaced with a hollow cylindrical pipe, and the space in the pipe also forms a capillary-like minute coating liquid rising path.
[0060]
In the modified example 10, a plate having a horizontal cross section having a sine wave shape or a sawtooth shape is used.
[0061]
In the eleventh modification, a fine wire mesh is sandwiched.
[0062]
In Modification 12, many hydrophilic fibers or hydrophilic carbon fibers oriented in the vertical direction are densely arranged in parallel, and in Modification 13, a cloth or nonwoven fabric made of hydrophilic fibers or hydrophilic carbon fibers. Is used.
[0063]
In the modified examples 14 to 15, as in the first embodiment, a partition plate made of a flat plate is used. However, a large number of spacer members 87 ′ and 87 ″ having a small width, that is, a small dimension in the coating width direction are substantially constant. The spacer members 87 ′ in the modified example 14 are in the form of an elongated plate and are collectively arranged at various places, that is, in the slit width direction (application direction of the coating apparatus). On the other hand, the spacer member 87 ″ in the modified example 15 has a substantially square cross section, and is arranged at a different position for each slit layer.
[0064]
In the modified example 16, ball-like or sand-like particles are densely embedded, and a continuous gap between them forms a capillary-like minute coating liquid rising path.
[0065]
In these modifications, the structural material or spacer sandwiched between the pair of nozzle basic members 86 may be made of metal or plastic as long as it has good wettability to the coating liquid and sufficiently causes capillary action. In addition, it may be a collection of many fibers or a metal foil or a plastic film.
[0066]
Even if it is the said modification 1-16, the effect similar to the above-mentioned 1st Example is acquired. In these modified examples, the wall surface that has wettability to the coating liquid and contributes to the capillary phenomenon is at least 1. in comparison with the case where these structures are not disposed when the wall surface appears in a horizontal section. 3 times or more, usually 1.5 times or more, preferably 1.7 times or more, more preferably 2 times or more.
[0067]
<Modifications 17-18>
In the first and second embodiments described above, the case where coating is performed on the lower surface of a substrate such as a glass substrate has been described as an example, but the same applies to flexible long members such as films and nonwoven fabrics. It can be carried out.
[0068]
In the modified example 17 shown in FIG. 6, the nozzle 82 of the first embodiment is arranged immediately below the backup roll 204, and the flexible long member (web) 202 is fed along the backup roll 204. I did it.
[0069]
In the modified example 18 shown in FIG. 7, two backup rolls 204-1 and 204-2 are arranged side by side, and the single slit nozzles 82'-1 and 82'- of the second embodiment are directly below each of them. 2 were arranged respectively. Similarly, the flexible long member (web) 202 is fed along the backup rolls 204-1 and 204-2.
[0070]
【The invention's effect】
The supply amount of the coating liquid to the substrate can be increased, and an increase in coating thickness can be realized.
[Brief description of the drawings]
FIG. 1 is an incision perspective view schematically showing a main part of a coating apparatus and a state of application to a lower surface of a glass substrate according to a first embodiment.
FIG. 2 is a schematic cut-away perspective view for explaining a drive mechanism for moving a nozzle and a liquid storage tank up and down, respectively.
FIG. 3 is a schematic front view of the coating apparatus viewed from the coating direction for further explaining the drive mechanism shown in FIG. 2;
FIG. 4 is a schematic longitudinal sectional view for explaining a main part of a coating apparatus according to a second embodiment.
FIG. 5 is a cross-sectional oblique view schematically showing the configuration of the nozzles of modified examples 1 to 16.
FIG. 6 is a longitudinal sectional view schematically showing a coating apparatus according to a modified example 17;
FIG. 7 is a longitudinal sectional view schematically showing a coating apparatus of Modification Example 18.
[Explanation of symbols]
28 Glass substrate 66 Liquid reservoir tank 78 Nozzle support shaft 82 Nozzle 83 Nozzle outlet 83a Coating area 83b Nozzle outlet on nozzle outlet 84 Slit opening 85 of liquid reservoir 85 Partition plate 86 Nozzle basic member 87 Spacer plate 88 Coating Industrial fluid rising path 89 Screw 98 Boots

Claims (6)

A nozzle having a coating liquid ascending path that is arranged to extend in the left-right direction to apply the coating liquid to the lower surface of a plate-like substrate that moves in the front-rear direction and guides the coating liquid to the discharge port by capillary action When,
In a coating apparatus comprising a liquid storage tank that houses the nozzle and supplies a coating liquid to the lower part of the coating liquid ascending path,
In the coating liquid rising path, a capillary phenomenon promoting member for promoting the capillary phenomenon of the coating liquid is provided,
The capillary phenomenon promoting member is a partition wall extending in the direction in which the coating liquid ascends, is a flat plate extending in the left-right direction, and the coating liquid ascent path is composed of two or more slit-shaped paths,
A coating apparatus, wherein a spacer plate for determining an interval between the slit-like paths is disposed at a position on the discharge port and sandwiching the application region, and the discharge port is closed at this position. The coating liquid is arranged to extend in the left-right direction to apply the coating liquid to the lower surface of the long base that moves in the front-rear direction by the backup roll, and the coating liquid rises to guide the coating liquid to the discharge port by capillary action A nozzle having a path;
In a coating apparatus comprising a liquid storage tank that houses the nozzle and supplies a coating liquid to the lower part of the coating liquid ascending path,
In the coating liquid rising path, a capillary phenomenon promoting member for promoting the capillary phenomenon of the coating liquid is provided,
The capillary phenomenon promoting member is a partition wall extending in the direction in which the coating liquid ascends, is a flat plate extending in the left-right direction, and the coating liquid ascent path is composed of two or more slit-shaped paths,
A coating apparatus, wherein a spacer plate for determining an interval between the slit-like paths is disposed at a position on the discharge port and sandwiching the application region, and the discharge port is closed at this position.   The coating apparatus according to claim 1 or 2, wherein the flat plate forming the partition wall and the spacer plate are held and held between a pair of basic members constituting the nozzle. A nozzle having a coating liquid ascending path that is arranged to extend in the left-right direction to apply the coating liquid to the lower surface of a plate-like substrate that moves in the front-rear direction and guides the coating liquid to the discharge port by capillary action When,
In a coating apparatus comprising a liquid storage tank that houses the nozzle and supplies a coating liquid to the lower part of the coating liquid ascending path,
A plurality of the nozzles are arranged side by side in the front-rear direction, and by further applying by the other nozzle after application by one nozzle, overcoating is performed on the substrate ,
Said spacer plate to determine the distance of the coating liquid increases path, the In the discharge Prompt disposed positions sandwiching the coating area, coating apparatus, characterized in that for closing the discharge port in this location. The coating liquid is arranged to extend in the left-right direction to apply the coating liquid to the lower surface of the long base that moves in the front-rear direction by the backup roll, and the coating liquid rises to guide the coating liquid to the discharge port by capillary action A nozzle having a path;
In a coating apparatus comprising a liquid storage tank that houses the nozzle and supplies a coating liquid to the lower part of the coating liquid ascending path,
A plurality of the nozzles are arranged side by side in the front-rear direction, and by further applying by the other nozzle after application by one nozzle, overcoating is performed on the substrate ,
A coating apparatus, wherein a spacer plate for determining an interval of the coating liquid ascending path is disposed at a position on the discharge port and sandwiching the application region, and the discharge port is closed at this position . The coating apparatus according to claim 4 or 5 , wherein the spacer plate is held and held between a pair of basic members constituting the nozzle.

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