JP3134742B2 - Coating device and coating method, color filter manufacturing device and manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method for a coating liquid, and more particularly to a liquid crystal display for forming a coating film having a uniform thickness by discharging the coating liquid on the upper surface of a flat sheet-like member. The present invention relates to a coating apparatus and a coating method suitable for manufacturing a color filter, and a color filter manufacturing apparatus and a manufacturing method using the apparatus and the method.

[0002]

2. Related Background Art A color filter for a color liquid crystal display has a fine lattice pattern of three primary colors on a glass substrate. Such a lattice pattern is formed by forming a black coating film on a glass substrate. , Red, blue and green. Therefore, in the production of a color filter, a coating process for forming a coating film by applying a black, red, blue, and green coating solution on a glass substrate is indispensable. Conventionally, a spinner, a bar coater or a roll coater has been used as a coating device in this type of coating process.However, in order to reduce the consumption of the coating liquid and to improve the physical properties of the coating film, it has been recently required that Use of a die coater is being considered.

[0003] The die coater is provided with a so-called slit die for applying a coating liquid, and this slit die is disclosed in, for example, JP-A-2-164480 and JP-A-6-154687. These known slit dies are all for applying a coating liquid to a flexible web such as a film or a tape.

[0004]

The known slit die uses the deflection of the web to discharge the coating liquid on one surface thereof. Cannot be applied. In addition, in the production of a color filter, it is necessary to control a coating film formed on a glass substrate to have a uniform film thickness, but simply using a known slit die can reduce the coating film thickness and uniformity. It cannot be maintained within the desired range.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to apply a coating liquid on the upper surface of a member to be coated even if the member to be coated is a hard member such as a glass substrate. An object of the present invention is to provide a coating apparatus and a coating method capable of easily forming a coating film having a uniform thickness, which can be easily discharged, and a manufacturing apparatus and a manufacturing method of a color filter using these apparatuses and the method. .

[0006]

The above object has been achieved by the present invention, and a coating apparatus for coating a glass substrate according to claim 1 comprises a supply means for supplying a coating liquid, and the supply means. An applicator having a discharge port extending in one direction for discharging the application liquid supplied from, and a moving means for relatively moving either the applicator or the member to be applied, and The applicator of the apparatus according to claim 1, when viewed in the relative traveling direction of the member to be coated, a front lip located on the traveling direction side, a rear lip located on the opposite side to the traveling direction, and a gap between these lips. The lip gap is formed, and each of both lips has at least a liquid contact surface forming a lip gap, and a lip lower surface that is continuous with the liquid contact surface and faces the member to be coated. , freon The lower end surface of the lip and rear lip identical
The front lip has a lower end surface that is shorter in the traveling direction than the rear lip lower end surface in the traveling direction .
The length of the lower end surface along the traveling direction is 0.5 mm or less
And the length of the lower end face of the rear lip is
1 mm or more.

According to the first aspect of the present invention, when the coating liquid is discharged from the discharge port of the coating device while the member to be coated is relatively advanced with respect to the coating device, the coating liquid is placed under the front and rear lips of the coating device. The coating liquid formed between the end face and the member to be coated is relatively moved by the member to be coated.
It does not fluctuate, and in this state, a coating film of the coating liquid is formed on the upper surface of the member to be coated. That is, the coating film is formed on the member to be coated while the boundary of the liquid pool contacting the lower end surface of the front lip is kept constant.

According to a second aspect of the present invention , in the coating apparatus, the length of the lower end face of the front lip is equal to 0. It is set to 2 mm or less, and in this case, the boundary of the liquid pool is stably maintained on the lower end surface of the front lip .

[0009] The length of the lower end surface of the rear lip is preferably set to below 4 mm. When this length is secured at the lower end surface of the rear lip, the meniscus generated in the liquid pool between the lower end surface of the rear lip and the member to be applied can be stably maintained. In the coating apparatus according to the third aspect, an inclined surface is formed on the front surface of the front lip, and the inclined surface is inclined toward the discharge port and connected to the lower end surface of the front lip. The inclined surface of the front lip is at least 30 ° and 60 ° with respect to the lower end surface.
It has the following angles. In this case, the liquid pool between the lower end surface of the front lip and the member to be applied does not wrap around to the inclined surface of the front lip, and the boundary of the liquid pool is stably maintained at the lower end surface of the front lip. .
Moreover, in this case, the lower end of the front lip is not excessively tapered, and the strength of the lower end is sufficiently ensured.

According to a fourth aspect of the present invention, the distance between the front lip and the rear lip for forming the discharge port is 0.05 mm.
It is set on more than. In this case, the flow resistance of the slit is maintained within a desired range, and the coating liquid is uniformly discharged from the discharge port of the coating device along the longitudinal direction .

[0011] coating apparatus of claim 5 is applied to the production of color filters, in this case, high-quality color filter can be obtained. In the color filter manufacturing apparatus according to the sixth aspect, a color filter is manufactured using any of the applicators according to the first to fifth aspects , and in this case, a high-quality color filter is obtained. According to a seventh aspect of the present invention, there is provided the coating method, wherein one of the coating device and the member to be coated is relatively moved while discharging the coating liquid from the discharge port of the coating device using the coating device according to the first aspect. , A coating film is formed on the member to be coated,
The operation in this case is the same as in the case of the coating apparatus of the first aspect. A method for manufacturing a color filter according to claim 8.
Manufactures a color filter using the coating method of claim 7.
Build.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a so-called die coater applied to the manufacture of a color filter, and the die coater includes a base 2. Base 2
A pair of guide groove rails 4 is provided on the upper side, and a stage 6 is disposed on these guide groove rails 4, and the upper surface of the stage 6 is configured as a suction surface. The stage 6 is reciprocally movable in the horizontal direction on the guide groove rail 4. Specifically, a pair of slide legs 8 project from the lower surface of the stage 6, and these slide legs 8 are slidably fitted to the corresponding guide groove rails 4. The outer plate member 4 a constituting each guide groove rail 4 is bent inward with its upper edge substantially at a right angle, and is fitted into a side groove 10 formed in the slide leg 8 of the stage 4.

A casing 12 having a built-in feed mechanism is disposed between the pair of guide groove rails 4, and the casing 12 extends along the guide groove rail 4. The feed mechanism has a feed screw 14 composed of a ball screw as shown in FIG. 2, and the feed screw 14 is screwed into a nut-like connector 16 fixed to the lower surface of the stage 6. Extends through it. Both ends of the feed screw 14 are rotatably supported by bearings (not shown), and an AC servo motor 18 is connected to one end thereof. The casing 1
An opening is formed on the upper surface of the connector 2 to allow the connector 16 to move, but the opening is omitted in FIG.

On the upper surface of the base 2, a sensor column 20 is disposed at one end thereof. The sensor support 20 is reverse L
It has a character shape, and its tip extends above one of the guide groove rails 4. An electric lifting actuator 21 is attached to the tip of the sensor support 20, and a thickness sensor 22 is attached to the lifting actuator 21 facing downward. As the thickness sensor 22, a laser displacement meter, an electronic micro displacement meter, an ultrasonic thickness gauge, or the like can be used.

Further, a sensor support 20 is provided on the upper surface of the base 2.
A die post 24 is disposed closer to the center of the base 2 than the base 2, and the die post 24 also forms an inverted L-shape. An elevating mechanism 26 is attached to the tip of the die column 24. The elevating mechanism 26 is provided with an elevating bracket (not shown in detail in FIG. 1). The elevating bracket is movable up and down on a pair of guide rods. Attached to. A feed screw composed of a ball screw is disposed between the guide rods, and the feed screw is screwed into the elevating bracket so as to pass through the elevating bracket. The upper end of the feed screw is rotatably supported via a bearing in a casing 28 that houses the guide rod and the feed screw, and an AC servo motor 30 is connected to the upper end thereof.

A U-shaped die holder 32 is rotatably mounted on the lifting bracket in a vertical plane. The die holder 32 extends horizontally above a pair of guide groove rails 4 between the rails 4. Extending. Further, a horizontal bar 36 is fixed to the lift bracket above the die holder 32.
Extends along the die holder 32. Pneumatic adjustment actuators 38 are attached to both ends of the horizontal bar 36, respectively. These adjustment actuators 38
Has extensible rods projecting from the lower surface of the horizontal bar 36, and these rods are in contact with both ends of the die holder 32.

A slit die 40 as an applicator is mounted in the die holder 32. As shown in FIG. 2, the supply hose 4 for the coating liquid is supplied from the slit die 40.
2 is extended, and the distal end of the supply hose 42 is connected to a supply port of an electromagnetic switching valve 46 of the syringe pump 44. A suction hose 48 extends from a suction port of the electromagnetic switching valve 46.
It is inserted into a tank 50 storing a coating liquid.

The pump body 52 of the syringe pump 44 is
The switching operation of the electromagnetic switching valve 46 enables the connection to one of the supply hose 42 and the suction hose 48 selectively. The electromagnetic switching valve 46 and the pump body 52 are electrically connected to a computer 54, and the operation thereof is controlled in response to a control signal from the computer 54. Computer 5
Reference numeral 4 also electrically connects the above-described lifting actuator 21 and thickness sensor 22.

Further, a sequencer 56 is also electrically connected to the computer 54 to control the operation of the syringe pump 44. The sequencer 56 includes an AC servomotor 18 of the feed screw 14 on the stage 6 side and an elevating mechanism 26,
In order to control the sequence, the sequencer 56 has a signal indicating the operation state of the AC servomotors 18 and 30, a signal from the position sensor 58 for detecting the moving position of the stage 6, and a slit. A signal from a sensor (not shown) for detecting the operation state of the die 40 is input, and a signal indicating a sequence operation is output from the sequencer 56 to the computer 54. Instead of using the position sensor 58, an encoder may be incorporated in the AC servomotor 18, and the position of the stage 6 may be detected by the sequencer 56 based on a pulse signal output from the encoder.

Although not shown, the die coater is provided with a loader for supplying a glass substrate A for a color filter as a single-wafer member on the stage 6 and an unloader for removing the glass substrate A from the stage 6. For these loaders and unloaders, for example, a cylindrical coordinate system industrial robot can be used as a main component.

As is clear from FIG. 1, the above-described slit die 40 extends horizontally between the pair of guide groove rails 4 in a direction orthogonal to the reciprocating direction of the stage 6.
Here, the horizontal adjustment of the slit die 40 is performed by the horizontal bar 36.
By moving the telescopic rods of the adjusting actuator 38 provided at both ends of the die, the die holder 32 is rotated around its rotation axis.

The details of the slit die 40 are shown in FIG. 3. In FIG. 3, the axis of rotation of the die holder 32, that is, the slit die 40, is indicated by a one-dot chain line. The slit die 40 includes a long block-shaped front lip 58 and a rear lip 60.
Numerals 0 are attached back and forth in the reciprocating direction of the stage 6 and are integrally connected to each other. Slit die 40
A manifold 62 is formed in a central part of the inside,
The manifold 62 extends in a direction perpendicular to the reciprocating direction of the stage 6. The manifold 62 is always connected to the above-mentioned coating solution supply hose 42 via an internal passage.

A slit 64 extends vertically downward from the manifold 62 and opens on the lower surface of the slit die 40. The lower end opening of the slit 64, that is, the discharge port 6
Reference numeral 6 extends in a direction perpendicular to the reciprocating direction of the stage 6 similarly to the manifold 62. Specifically, a shim (not shown) is provided between the front lip 58 and the rear lip 60.
The thickness of the shim causes the slit 6
4 and the gap LP between the discharge ports 66, that is, the length along the reciprocating direction of the stage 6 is, for example, 0.05 mm or more.
It is set to 3 mm or less.

When the stage 6 moves toward the slit die 40 from the state shown in FIG. 1, the front lip 5 located on the front side in the forward movement direction (the direction of arrow B in FIG. 3).
8, the lower part of the front surface is formed on an inclined surface 68 inclined toward the discharge port 66, and between the lower end edge of the inclined surface 68 and the discharge port 66, the lower end surface 70 of the front lip 58 is formed. Stipulated. On the other hand, regarding the rear lip 60, the lower end of the rear surface is formed on an inclined surface 72 inclined toward the discharge port 66, and the rear lip 60 is disposed between the lower end edge of the inclined surface 72 and the discharge port 66. Lower end surface 74
Is stipulated.

When viewed in the reciprocating direction of the stage 6, as shown in FIG.
Is shorter than the length LR of the lower end surface 74 of the rear lip 60, and the lower end surfaces 70 and 74 are located in the same horizontal plane. For example, the length LF of the lower end face 70 is set to 0.5 mm or less, and the length LR of the lower end face 74 is set to 1 mm or more and 4 mm or less.

Further, in the front lip 58, the angle θF between the inclined surface 68 and the horizontal plane is 30 ° or more,
It is set to 60 ° or less. On the other hand, with respect to the rear lip 60, the angle θR between the inclined surface 72 and the horizontal plane is not particularly limited, but is desirably set to the same range as θF. Next, one process related to the production of the color filter, that is, a coating method performed using a die coater having the above-described slit die 40 will be described.

First, when the origin return of each operating portion of the die coater is performed, the stage 6 is positioned below the thickness sensor 22 and the suction hose 48
The inside of the path leading to the manifold 62 and the slit 64 in the slit die 40 via the supply hose 42 is filled with the coating liquid. In this state, a glass substrate A is supplied onto the stage 6 from a loader (not shown), and the glass substrate A is held on the stage 6 by receiving a suction pressure. When the loading of the glass substrate A is completed, the thickness sensor 22 is lowered to a predetermined position, and the thickness of the glass substrate A is measured by the thickness sensor 22. After the measurement, the thickness sensor 22 is raised to the original position.

Simultaneously with the start of the loading of the glass substrate A described above, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 to the suction hose 48. A suction operation of sucking the application liquid through the suction hose 48 is performed. When a predetermined amount of the application liquid is sucked into the syringe pump 44, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 and the supply hose 42, and the stage 6 is connected to the slit die 40. And is stopped immediately before the slit die 40. Thereafter, the slit die 40 is lowered, and a predetermined clearance between the lower end surfaces 70 and 74 of the slit die 40 and the upper surface of the glass substrate A, that is, several times the thickness of the coating film to be formed, for example, A clearance of 0.05 to 0.2 mm is secured. The clearance is determined based on an output signal from a distance sensor (not shown) that measures the distance between the stage 6 and the slit die 40 in consideration of the thickness of the glass substrate A measured by the thickness sensor 22. It is determined exactly by controlling the descent.

Next, the stage 6 is further moved forward, and a start line at which the coating film is to be started is positioned immediately below the discharge port 66 of the slit die 40 on the upper surface of the glass substrate A, and the stage 6 is temporarily stopped. At substantially the same time as the stage 6 is temporarily stopped, the syringe pump 44 starts the operation of discharging the application liquid, and supplies the application liquid toward the slit die 40. Therefore, the coating liquid is discharged onto the glass substrate A from the discharge port 66 of the slit die 40. Here, since the gap LP of the discharge port 66 is constant along the longitudinal direction of the slit die 40, that is, in the direction orthogonal to the reciprocating direction of the stage 6, the discharge port 66 extends from the discharge port 66 to the start line of the glass substrate A. The coating liquid is discharged uniformly along the start line, and as a result, a liquid pool C (see FIG. 3) having a meniscus is formed between the slit die 40 and the glass substrate A along the start line.

When the stage 6 is moved in the forward direction at a constant speed while the discharge of the coating liquid from the discharge port 66 is continued simultaneously with the formation of the liquid pool C as shown in FIG. Thus, the coating film D of the coating liquid is continuously formed on the upper surface of the guide substrate A. When forming the coating film D, the start line of the glass substrate A is not stopped once without stopping the forward movement of the stage 6.
The application liquid may be discharged from the discharge port 66 at the timing of passing through the coating liquid 6.

As the stage 6 advances, when the finish line on which the formation of the coating film D on the glass substrate A should be finished reaches a position immediately before the slit die 40 and the discharge port 66,
At this point, the discharge operation of the syringe pump 44 is stopped. In this way, even if the discharge of the coating liquid from the slit die 40, that is, the discharge port 66 thereof is stopped, the coating liquid D in the liquid pool C is consumed (squeezed) on the upper surface of the glass substrate A while the coating liquid D is discharged. Formation continues to the finish line. Note that the discharge operation of the syringe pump 44 may be stopped when the finish line on the glass substrate A passes through the discharge port 66 of the slit die 40.

When the finish line on the glass substrate A passes or passes through the discharge port 66, the suction operation of the syringe pump 44 is slightly performed, whereby the coating liquid in the slit 64 of the slit die 40 is It is sucked into the manifold 62 side. After this, slit die 4
0 is raised to the original position, and the step of discharging the coating liquid from the slit die 40 ends. At the ascending position of the slit die 40, the coating liquid adhering to the lower end surface is wiped off by a cleaner (not shown).

On the other hand, the forward movement of the stage 6 is continued even after the end of the application liquid discharging step, and the forward movement is stopped when the stage 6 reaches the end of the guide groove rail 4. In this state, the glass substrate A on which the coating film D is formed is removed from the stage 6 by the unloader. Thereafter, the stage 6 is moved back, returned to the initial position shown in FIG. 1, and a series of coating steps is completed. At the initial position, the stage 6 waits until a new glass substrate is loaded.

Since the die coater for forming the coating film D on the glass substrate A is provided with the above-mentioned slit die 40, the coating film D can be formed uniformly, which is suitable for the production of a color filter. Become. That is, with respect to the slit die 40, since the length LF of the lower end face 70 of the front lip 58 is shorter than the length LR of the lower end face of the rear lip 60, the boundary line E (see FIG. 3) of the liquid pool C is formed. It can be reliably maintained on the lower end surface 70. Therefore, during the formation of the coating film D, the shape of the liquid pool C does not change, and the thickness of the coating film D becomes uniform. In this case, if the length LF of the lower end face 70 is set to 0.5 mm or less, it is ensured that the boundary E of the liquid pool C crosses over the lower end face 70 due to surface tension and goes around the front side of the front lip 58. Can be prevented. In this regard, if the angle θF of the inclined surface 68 connected to the lower end surface 70 is 30 ° or more, the boundary E of the liquid pool C does not protrude to the inclined surface 68, and If the angle θF exceeds 60 °, the rigidity of the lower end of the front lip 58 may be insufficient.

If the boundary line E of the liquid pool C goes around the front side of the front lip 58, the thickness of the coating film D cannot be kept thin. The lower end surface of the front lip 58 may have a length LF of 0, that is, an edge shape, but in this case, it is difficult to secure the rigidity of the edge. When the lower end surfaces 70 and 74 of the front lip 58 and the rear lip 60 are in the same horizontal plane, both boundaries defining the upper edge of the liquid pool C are stably maintained, and the shape of the liquid pool C becomes unstable. Never.

The lower end surface 74 of the rear lip 60 has a length L
Since R is set to 1 mm or more and 4 mm or less, a meniscus can be reliably formed between the lower end surface 74 and the glass substrate A. Further, the gap Lp of the slit 64
Is secured to 0.05 mm or more, the flatness of the inner surfaces of the front lip 58 and the rear lip 60 defining the slit 64 can be sufficiently ensured in terms of processing accuracy. On the other hand, when the gap Lp exceeds 0.3 mm, the discharge pressure of the coating liquid in the slit 64 and the manifold 62 decreases, and the coating liquid can be uniformly discharged from the discharge port 66 of the slit die 40. Can not.

The lengths LF and LR of the lower end surfaces 70 and 74 described above.
Table 1 below shows the results of experiments in which a coating film D was formed on a glass substrate A with various changes. In this experiment, slit 6
4, the gap LP is 0.1 mm, the size of the glass substrate A is 400 × 300 mm in length and width, and the thickness of the coating film D to be formed is 1.6 μm.
m, the moving speed of the stage 6 is set to 3 m / min.

[0038]

[Table 1]

As is apparent from Table 1 above, the lower end surface 70
When the length LF is 0.6 mm or more,
If the length LR is less than 1 mm, the coating film D cannot be formed satisfactorily. In the description of the above embodiment,
Although the description has been given with respect to the formation of a coating film on a single-wafer member such as a glass substrate, the apparatus and the method of the present invention can be applied to continuous application of a coating liquid to a long member to be coated or endless member to be coated Application is also possible. Further, in the case of the above-described embodiment, the applicator is arranged downward, but even if the applicator is arranged sideways or upward, a coating film having a uniform thickness is similarly formed on the member to be applied. be able to.

[0040]

I have described above, according to the present invention urchin claim 1, 5, 7 The method of coating apparatus and coating of the invention and claims
According to the color filter manufacturing apparatus and the manufacturing method of 6 , 8 , the length of the lower end surface of the applicator, that is, the front lip, is shorter than the lower end surface of the rear lip. As a result, the coating liquid can be easily applied and the thickness of the coating film can be made uniform. As a result, when the member to be applied is a single-wafer member, that is, a glass substrate for a color filter,
High quality color filters can be obtained.

According to the coating apparatus of the second aspect, there is a further advantage in stabilizing the shape of the liquid pool. Claim 3,
According to the coating device of No. 4 , not only is there an advantage in stabilizing the shape of the liquid pool, but also there are great advantages in rigidity and processing accuracy of the coating device.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a die coater according to one embodiment.

FIG. 2 is a schematic configuration diagram showing the die coater of FIG. 1 including a coating liquid supply system.

FIG. 3 is a sectional view of a slit die used in the die coater of FIG.

[Explanation of symbols]

 6 Stage 14 Feed Screw 40 Slit Die (Applicator) 44 Syringe Pump (Supplying Means) 50 Tank 58 Front Lip 60 Rear Lip 62 Manifold 64 Slit 66 Discharge Port 68,72 Inclined Surface 70,74 Lower End Surface

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-229481 (JP, A) JP-A-4-61958 (JP, A) JP-A-6-151296 (JP, A) JP-A-8- 52404 (JP, A) WO 94/27737 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05C 5/00-5/04 B05D 1/26 G02F 1/1335 G02B 5 / 20-5/28

Claims (8)

(57) [Claims] A supply unit for supplying a coating liquid; a coating unit having a discharge port extending in one direction for discharging the coating liquid supplied from the supply unit; and one of the coating unit and the member to be coated. A coating apparatus for coating a glass substrate with a moving means for relatively moving one of the members, wherein the coating device is located on the side of the traveling direction when viewed in the relative traveling direction of the member to be coated. And a front lip located at
A rear lip located on a side opposite to the traveling direction, and a lip gap formed between the two lips; each of the two lips has at least a liquid contact surface forming the lip gap; the continuous with the liquid level with and a lip lower end face facing the application target member, the full
The lower end faces of the long lip and the rear lip are in the same plane.
Ri, and along the lower end surface of the front lip rather short than the length length along the direction of travel along the traveling direction of the lower end surface of the rear lip, in the traveling direction of the lower end surface of the front lip
Is less than 0.5 mm and the rear lip
Wherein the length of the lower end surface is 1 mm or more . 2. A length of the lower end surface of the front lip along the traveling direction is equal to 0.1. The coating device according to claim 1, wherein the coating device has a thickness of 2 mm or less. 3. A front surface of the front lip is formed with an inclined surface inclined toward the discharge port and connected to a lower end surface thereof, and an angle of the inclined surface with respect to the lower end surface is 30.
The angle is not less than 60 ° and not more than 60 °.
Or the coating device according to 2 . Gap between said front lip the rear lip that wherein forming said discharge port is characterized in that a on 0.05mm or more, the coating apparatus according to any one of claims 1-3. 5. characterized in that it is used for manufacturing a color filter, a coating apparatus according to any one of claims 1-4. 6. The apparatus for manufacturing a color filter, which comprises manufacturing a color filter using any of the coating apparatus of claim 1 to 5. 7. Using the applicator according to claim 1, by moving one of the applicator and the member to be applied relatively while discharging the application liquid from a discharge port of the applicator. Forming a coating film of a coating liquid on the member to be coated. 8. A method for manufacturing a color filter, comprising manufacturing a color filter using the coating method according to claim 7 .