JP2001162204A - Coating eqipment using capillary phenomenon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the coating thickness in coating equipment introducing a coating liquid from the liquid storing tank to the top of the nozzle. SOLUTION: A slit-like coating liquid rising pass 88 extends from the lower face of a nozzle 82 to the exit 83 positioned between a pair of nozzle basic components constituting the nozzle 82. This coating liquid rising pass 88 is composed of four layers of slit-like passes 88-1 to 88-4 divided by three plane screens 85. The feeding of the coating liquid is conducted through the slit-like passes 88-1 to 88-4 by means of capillary phenomenon, so that the amount of feeding the coating liquid is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates 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 cloth or a nonwoven fabric. A coating device for applying a coating liquid,
And a nozzle used for the same. In particular, the present invention relates to a coating apparatus and a nozzle using capillary action.

[0002]

2. Description of the Related Art In the field of semiconductors and flat panel displays,
As a technique for forming a uniform film for forming a protective film or the like on a substrate, spin coating or the like has been generally used.

[0003] However, spin coating has a problem that a raised portion is formed at the edge of the substrate and that the coating liquid jumps up. In addition, there has been a problem that the coating cannot be performed only on a predetermined region of the substrate, and that a large amount of the coating liquid is wasted, so that the cost cannot be reduced.

In recent years, there has been proposed a coating apparatus for performing coating using a capillary phenomenon (Japanese Patent Laid-Open No. 8-22528).
No., JP-A-6-43908). In such a coating apparatus, a nozzle extending linearly in the width direction of the coating is provided with a slit-shaped coating liquid rising path for guiding the coating liquid to a discharge port of the nozzle by a capillary phenomenon. A coating liquid is applied to the lower surface of the base material to be coated.

More specifically, the nozzle is submerged in a liquid storage tank with a lid extending linearly in the width direction of the application, and at the time of coating, the lid is opened and the nozzle is raised to discharge the upper end of the nozzle. The outlet protrudes upward so as to be located close to the lower surface of the substrate. Then, the meniscus on the nozzle discharge port is brought into contact (liquid contact) with the lower surface of the base material to perform coating.

According to such a method, the coating liquid is supplied to the discharge port by capillary action only through one slit-like coating liquid rising path.

[0007]

Therefore, it is suitable for coating a thin film having a considerably small thickness, but the coating thickness cannot be increased beyond a certain limit. By adjusting the slit width of the coating liquid ascending path, the supply amount of the coating liquid can be increased within a certain range, but the slit width is increased to a predetermined width or more due to the use of the capillary phenomenon. Then, on the contrary, the supply amount of the coating liquid is reduced.

For the purpose of increasing the coating thickness, it has been considered to adjust the coating speed or increase the concentration of the coating liquid. However, even if the concentration is increased, the supply amount decreases due to the increase in viscosity. In many cases, the effect was hardly obtained due to reasons such as doing so.

It is also conceivable to take measures such as reducing the height of the rise of the coating liquid from the liquid level in the liquid reservoir to the discharge port at the tip of the nozzle, and reducing the gap between the tip of the nozzle and the base material. However, even if these were optimized, the coating thickness could not be increased so much.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in a coating apparatus for guiding a coating liquid from a reservoir to a nozzle tip by capillary action, it is possible to increase coating thickness or improve coating processing efficiency. It is to provide a coating device that can be realized.

[0011]

According to the present invention, there is provided a coating apparatus comprising:
A nozzle having a coating liquid ascending path arranged to extend in the left-right direction to apply the coating liquid to the substrate moving in the front-rear direction and having the coating liquid ascending path for guiding the coating liquid to the discharge port by capillary action, and contains the nozzle. And a reservoir for supplying a coating liquid to a lower portion of the coating liquid rising path, wherein the coating liquid rising path includes a capillary phenomenon promoting member for promoting a capillary phenomenon of the coating liquid. Is provided.

According to the above configuration, the supply amount of the coating liquid to the substrate can be increased, and the coating thickness can be increased.

According to a second aspect of the present invention, there is provided a coating apparatus which extends in the left-right direction to apply a coating liquid to a web moving in a front-rear direction, and guides the coating liquid to a discharge port by capillary action. In a coating apparatus including a nozzle having a liquid rising path and a liquid storage tank that stores the nozzle and supplies a coating liquid to a lower part of the coating liquid rising path, the coating liquid rising path includes:
It is characterized in that a capillary action promoting member for promoting the capillary action of the coating liquid is provided.

According to a fourth aspect of the present invention, in the coating apparatus, the partition wall as the capillary action promoting member is a flat plate extending in the left-right direction, and the coating liquid ascending path is composed of two or more slit-shaped paths. It is characterized by.

With such a configuration, the supply amount of the coating liquid can be greatly increased only by adding a simple structural member.

According to a fifth aspect of the present invention, the flat plate forming the partition wall and the spacer plate are sandwiched and held between a pair of basic members constituting the nozzle. .

With such a configuration, the position of the closed area on the discharge port can be freely changed, and the coating width can be easily changed.

In the coating apparatus according to the seventh and eighth aspects, the coating apparatus 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 long base material moving in the front-rear direction. A nozzle having a coating liquid rising path for guiding a coating liquid to a discharge port by a phenomenon, and a liquid reservoir containing the nozzle and supplying a coating liquid to a lower part of the coating liquid rising path. In the processing apparatus, a plurality of the nozzles are arranged in the front-rear direction, and after the application by one of the nozzles, the application is further performed by the other nozzles, so that the base material is overcoated. And

According to the above configuration, the supply amount of the coating liquid to the substrate can be increased, and the coating thickness can be increased.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a cutaway perspective view schematically showing a main part of a coating apparatus and a state of coating on the lower surface of a glass substrate 28. Here, the glass substrate 28 is used for a display panel or the like of a liquid crystal display device.
This is for forming a protective film.

The nozzle 82 linearly extending in the coating width direction is
In the central coating area, the coating liquid is sequentially supplied to the lower surface of the glass substrate 28 that moves substantially horizontally. That is, with the movement of the glass substrate 28, the coating liquid that wets the glass substrate 28 is sequentially pulled up 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, and the coating liquid is applied. Done.

The nozzle 82 has a beak-shaped discharge port 83 projecting upward from a substantially rectangular or substantially trapezoidal main body in a transverse cross section (cross section in the coating direction), and extends vertically from the lower surface to the discharge port 83. It has a slit-shaped coating liquid rising path 88 extending. As shown in the cross section, the coating liquid rising path 88 is divided by a flat partition plate 85 to form a multilayer slit. In the illustrated example, the nozzle 8
Two partition plates 85 are sandwiched between a pair of nozzle basic members 86 constituting the two through a spacer plate 87 to form four layers of slit-like paths 88-1 to 88-4. 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 rising path 88.

The nozzle 82 is housed in a liquid reservoir 66 and is submerged in the coating liquid stored in the liquid reservoir 66 except for the discharge port 83 when performing application.

As shown in the figure, the liquid storage tank 66 has a cross section having a shape in which the letter C of the alphabet is turned to the left. The discharge port 83 protrudes upward. Here, the height of the liquid level in the liquid storage tank 66 is maintained at a predetermined level by a liquid level height adjustment mechanism described later. Further, the height positions of the nozzle 82 and the liquid reservoir 66 are also maintained at predetermined values by a vertical movement / support mechanism described later.

At both ends of the nozzle 82 in the coating width direction, 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 as described later,
It is moved up and down via the nozzle support shaft 78. The upper end of the nozzle support shaft 78 penetrates the bottom surface of the liquid reservoir 66, and a bellows-like boot (closing member) 98 having a mouth joined to the opening of the bottom surface is provided, so that the coating liquid leaks. Dispensing is prevented.

The application area 83a on which the coating is performed on the discharge port 83 is sandwiched from both sides in the coating width direction by a closed area 83b in which the discharge port 83 is closed by the spacer plate 87. In a region 83c outside the closed region 83b, a meniscus 90a of the coating liquid 90 is formed as shown in the figure.

The three partition plates 85 are provided with screw holes at both ends, and are fixed by screws 89 between a pair of nozzle basic members 86. At this time, a spacer plate 87 is sandwiched between the partition plates 85 and between the partition plate 85 and the nozzle basic member 86 at the locations where the pair of closed regions 83b are formed. Therefore, for example, the nozzle 82 is provided with eight spacer plates 87, four on each side.
Is sandwiched.

At the lower end of the nozzle 82, there is formed a coating liquid introducing section having a trumpet-shaped cross section which opens downward from the lower ends of the slit-shaped passages 88-1 to 88-4. That is, in each nozzle basic member 86, at a position desired at the coating liquid introduction portion at the lower end of the inner surface,
A slope 86b is formed.

In the nozzle of the present embodiment, as described above, the coating liquid rising path 88 is formed as a multilayer slit, and each partition wall 85 contributes to the lifting of the coating liquid 90 by capillary action. In a coating nozzle using a capillary phenomenon, a larger amount of coating liquid can be supplied than in a conventional nozzle using a single-layer slit.

That is, the coating thickness is increased by the number of the slit-like paths 88-1 to 4-4 as compared with the conventional case.

The nozzle basic member 86 and the partition plate 85 are
In a specific example, it is made of stainless steel, but may be made of another metal, plastic, or the like as long as the material has good wettability to a coating liquid and sufficiently causes a capillary phenomenon.

According to the above embodiment, even if the supply amount of the coating liquid is increased in this way, the additional members are only 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 only by changing the position where the spacer plate 87 is arranged. Therefore, it is possible to easily set and change the application width.

By providing the closed regions 83b in which the discharge ports 83 are closed on both sides of the coating region 83a, it is possible to effectively prevent a change in the coating thickness at both ends of the coating region 83a. it can. Closed area 83b
Is not provided, the coating liquid is drawn from the meniscus 90a of the coating liquid 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
Since the surface tension from the meniscus 90a acts, the coating thickness changes at both ends of the coating width and in the vicinity thereof.

Next, referring to FIGS. 2 and 3, a supporting / driving mechanism for supporting and moving the nozzle 82 up and down, and a liquid reservoir 66
A brief description will be given of a supporting / driving mechanism for supporting and vertically moving.

The liquid reservoir 66 is supported from the base plate 32 via a liquid reservoir support member 54 having an L-shaped cross section and movable wedges 34 and 36 each having a wedge shape.

The reservoir support member 54 protrudes downward from a vertical plate 56 having a liquid reservoir 66 fixed to the upper end thereof, a horizontal plate 58 connected to the lower end of the vertical plate 56, and a central portion of the horizontal plate 58. The guide shaft receiving portion 65 receives the guide shaft 64 from the base plate, and the legs 60 and 62 project downward from the horizontal plate 58 on both sides of the guide shaft receiving portion 65.

The movable cotters 34, 36 have a slide-shaped slope on which the legs 60, 62 of the reservoir support member 54 are placed, and have a servomotor 52 and a ball screw 50.
Is driven in the application width direction. That is, when the movable cotters 34 and 36 are driven in the application width direction, the liquid reservoir support member 54 is precisely moved up and down. At this time, the guide shaft 64 and the guide shaft receiving portion 65 prevent the liquid tank supporting member 54 from being displaced in the horizontal direction.

The legs 60, 62 and the movable cotter 34,
The linear ways 42 and 48 are formed between the movable cotters 34 and 36, and the linear ways 38 and 44 are similarly formed between the movable cotters 34 and 36 and the base plate 32.

On the other hand, nozzle support shafts 78 and 80 supporting both ends of the nozzle 82 are supported by the liquid reservoir support member 54 via a vertically movable plate 74 and a horizontally movable plate 70.

The horizontal plate 58 of the reservoir support 54 is mounted on the up-and-down movable plate 74 for supporting the reservoir support 54.
A guide shaft receiving portion 75 for receiving a guide shaft 76 protruding upward from is joined. This allows
The vertical movable plate 74 is prevented from being displaced in the horizontal direction.

The horizontal movable plate 70 is supported by the vertical plate 56 of the reservoir supporting member 54 via a pair of linear ways 68 arranged in the horizontal direction, and is driven by the air cylinder 71 in the coating width direction.

The vertically movable plate 74 for supporting the liquid reservoir support member 54 is supported by the horizontally movable plate 70 via a pair of linear ways 72 which are diagonally arranged and descend to one side. It is driven up and down as it is driven in the direction. In this way, the nozzle 82 is driven up and down through the horizontal driving of the horizontally movable plate 70 in accordance with the driving of the air cylinder 71.

The glass substrate 28 is supported by a suction table 24 having a suction mechanism and is moved at a predetermined speed. For details of the suction table 24 and other components of the coating apparatus and detailed steps of coating, see Japanese Patent Application No.
Same as 45497.

FIG. 3 shows a liquid level height detecting tube 112 protruding from the liquid storage tank 66 in a horn shape, and as shown in detail in Japanese Patent Application No. 11-245497. A surface detection sensor is provided for controlling the supply amount of the coating liquid from the coating liquid tank to the liquid reservoir 66 by a pump. By the balance between the drain tube from the liquid reservoir 66 and the supply amount of the coating liquid, the liquid level in the liquid reservoir 66 is maintained at a predetermined value.

With the vertical movement / support mechanism as described above,
Precise vertical movement and setting of the height position can be realized by a simple structure.

<Second Embodiment> Next, a coating apparatus according to a second embodiment will be described with reference to a schematic sectional view of FIG.

In this embodiment, as shown in FIG. 4, a single-layer slit nozzle 82 'similar to that of the prior art is provided twice, and two nozzles 82'-
Coating is performed almost continuously from 1, 82'-2. That is, the two nozzles 82'-1 and 82'-2 are arranged side by side so as to overlap in the coating direction, and after the coating is performed by the first nozzle 82'-1 and further the second nozzle 82 '. -
When the coating is performed according to 2, the multi-layer coating is performed.

Therefore, similarly to the case of the above embodiment, compared with the case of using the capillary action type coating nozzle of the prior art,
The supply amount of the coating liquid per unit time can be increased, and the coating thickness can be increased.

In this embodiment, the spacer plate 8
By providing closed regions 83b such as 7 on both sides of the coating region 83a, it is possible to prevent a change in the coating thickness at both ends of the coating region. Further, precise and reliable vertical movement can be performed by using the above-mentioned vertical movement drive mechanism.

<Modifications 1 to 16> Next, nozzles of Modifications 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.

In the modified example 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 minute capillary-shaped coating liquid rising path is formed between the adjacent round bar and the flat wall of the nozzle basic member 86.

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 fine capillary liquid coating liquid rising path.

In the third modification (3), a plate in which a large number of vertical grooves (vertical grooves) are densely arranged on one side is sandwiched between a pair of nozzle basic members 86, and the large number of vertical grooves However, each of them forms a capillary-like fine coating liquid rising path.

In the modified examples 4 to 5 (4 to 5), a plate in which a large number of vertical through holes (vertical holes) are densely arranged is sandwiched between a pair of nozzle basic members 86. Each of them forms a capillary-like fine 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.

In the modified example 6 (6), a plate made of a porous metal sintered body is sandwiched between a pair of nozzle basic members 86. The complex continuous voids in the metal sinter form a large number of capillary microfluid rise paths.

In the modified example 7 (7), a plate having a horizontal cross section in the form of a pulse wave, that is, a plate in which a large number of vertical grooves (vertical grooves) are densely arranged on both surfaces is a pair of nozzle basic members 86. The plurality of flutes, which are sandwiched between them, each form a capillary-like fine coating liquid rising path.

In a modified example 8 (8), a number of vertical round bars whose diameter is smaller than the interval between the slits are densely arranged in a slit-like path between a pair of nozzle basic members 86. As a result, a large number of capillary-like fine coating liquid rising paths are formed between the round bars or between the round bar and the flat wall of the nozzle basic member 86.

In the modified example 9 (9), the round bar of the modified example 8 is replaced by a hollow cylindrical pipe, and the space in the pipe also forms a fine capillary liquid coating liquid rising path.

In the tenth modification, a plate whose horizontal section is sinusoidal or saw-toothed is used.

In the eleventh modification, a fine wire mesh is sandwiched.

In the twelfth embodiment, a large number of vertically oriented hydrophilic fibers or hydrophilic carbon fibers are densely arranged in parallel. In the thirteenth embodiment, the fibers are made of hydrophilic fibers or hydrophilic carbon fibers. Cloth or non-woven fabric is used.

In Modifications 14 and 15, similar to the first embodiment, a partition plate made of a flat plate is used, but the spacer member 8 having a small width, that is, a small dimension in the application width direction is used.
7 ', 87 "are used in parallel at substantially constant intervals. The spacer member 87' in Modification 14 is
It has an elongated plate shape and is arranged in some places. That is, they are arranged so as to overlap in the width direction of the slit (application direction of the application device). On the other hand, the spacer member 87 "in Modification 15 has a substantially square cross section, and is arranged at a different position for each slit layer.

In the sixteenth modification, ball-shaped or sand-shaped particles are densely embedded, and continuous voids between them form a capillary-like fine coating liquid rising path.

In these modifications, the structural material or spacer sandwiched between the pair of nozzle basic members 86 is
As long as the material has good wettability to the coating liquid and causes sufficient capillary action, it may be made of metal or plastic, may be made of a large number of fibers, or may be made of metal foil or plastic film. .

In the first to sixteenth modifications, substantially the same effects as in the first embodiment can be obtained. In these modified examples, the wall surface which has wettability to the coating liquid and contributes to the capillary phenomenon is at least 1.10 when viewed in a horizontal cross section, as compared with a case where these structures are not arranged.
It is at least 3 times, usually at least 1.5 times, preferably at least 1.7 times, more preferably at least 2 times.

<Modifications 17 and 18> In the first and second embodiments, the case where coating is performed on the lower surface of a substrate such as a glass substrate has been described as an example. The coating can be applied to the member in exactly the same manner.

In a seventeenth modification shown in FIG. 6, the nozzle 82 of the first embodiment is disposed immediately below the backup roll 204 so that the flexible elongate member (web) 202 moves along the backup roll 204. Was sent.

In a modification 18 shown in FIG. 7, two backup rolls 204-1 and 204-2 are arranged side by side, and immediately below each of them, the single slit nozzle 82'-1 of the second embodiment, 82'-2 were respectively arranged. And
Similarly, the flexible elongate member (web) 202 is fed along backup rolls 204-1 and 204-2.

[0070]

According to the present invention, the supply amount of the coating liquid to the substrate can be increased, and the coating thickness can be increased.

[Brief description of the drawings]

FIG. 1 shows a main part of a coating apparatus according to a first embodiment, and
FIG. 3 is a cutaway perspective view schematically showing a state of application on a lower surface of a glass substrate.

FIG. 2 is a schematic cutaway perspective view for explaining a drive mechanism for moving a nozzle and a liquid reservoir tank up and down, respectively.

FIG. 3 is a view for further explaining the drive mechanism shown in FIG. 2;
It is a schematic front view of the coating device seen from the coating direction.

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 nozzles of Modification Examples 1 to 16.

FIG. 6 is a longitudinal sectional view schematically showing a coating apparatus of Modification 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 78 Nozzle Support Shaft 82 Nozzle 83 Nozzle Discharge Port 83a Application Area on Nozzle Discharge Port 83b Closed Area 84 Slit Opening of Reservoir Tank 85 Partition Plate 86 Nozzle Basic Member 87 Spacer Plate 88 Coating Fluid ascent path 89 Screw 98 Boots

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeo Hiasa 101, Oji Kawai, Kawai-machi, Kitakatsuragi-gun, Nara F-term in Hirano Tecseed Co., Ltd. EA05 4F040 AA22 AB04 AC01 BA02 CA03 CA13 CA15 DA12

Claims (8)

[Claims] An apparatus is provided so as to extend in the left-right direction so as to apply a coating liquid to a lower surface of a plate-shaped substrate moving in a front-rear direction.
A nozzle having a coating liquid rising path for guiding the coating liquid to the discharge port by capillary action, and a liquid storage tank that houses the nozzle and supplies the coating liquid to a lower portion of the coating liquid rising path. In the coating apparatus, a capillary action promoting member for promoting a capillary action of the coating liquid is provided in the coating liquid rising path. 2. A coating liquid is applied to the lower surface of a long base material moved in the front-rear direction by a backup roll so as to extend in the left-right direction so as to apply the coating liquid to the lower surface. A coating apparatus comprising: a nozzle having a coating liquid ascending path to be guided; and a liquid storage tank that accommodates the nozzle and supplies a coating liquid to a lower part of the coating liquid ascending path. A coating device, further comprising a capillary phenomenon promoting member for promoting the capillary phenomenon of the coating liquid. 3. The capillarity promoting member may be a partition wall extending in a direction in which the coating liquid rises, or a rod-like, fibrous,
The coating device according to claim 1, wherein the coating device is configured by a mesh-like, granular, or porous structure, an uneven wall, or a curved wall. 4. The partition wall as the capillary action promoting member is a flat plate extending in the left-right direction, and the coating liquid ascending path includes two or more slit-shaped paths. Coating equipment. 5. The apparatus according to claim 1, wherein a spacer plate for determining an interval between the slit-shaped paths is disposed on the discharge port at a position sandwiching the application area, and closes the discharge port at this position. Item 6. The coating device according to Item 4. 6. The coating according to claim 5, wherein the flat plate forming the partition wall and the spacer plate are held by being sandwiched between a pair of basic members forming the nozzle. apparatus. 7. A plate-like base material that moves in the front-rear direction and is disposed so as to extend in the left-right direction so as to apply a coating liquid to a lower surface of the base material.
A nozzle having a coating liquid rising path for guiding the coating liquid to the discharge port by capillary action, and a liquid storage tank that houses the nozzle and supplies the coating liquid to a lower portion of the coating liquid rising path. In the coating apparatus, a plurality of the nozzles are arranged side by side in the front-rear direction, and by performing further coating by another nozzle after coating by one nozzle, performing multiple coating on the base material. Characteristic coating equipment. 8. A coating liquid is applied to the lower surface of a plate-like or long base material moving in the front-rear direction so as to extend in the left-right direction, and the coating liquid is discharged to a discharge port by capillary action. A nozzle having a coating liquid ascending path for guiding, and a coating apparatus including a liquid storage tank that accommodates the nozzle and supplies a coating liquid to a lower portion of the coating liquid ascending path; A coating apparatus which is arranged side by side in the front-rear direction, and performs application by one of the nozzles and further application by other nozzles, thereby performing multi-coating on the base material.