JP4934892B2 - Coating apparatus and coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus and a coating method for coating a coating solution on a substrate to be coated, and in particular, uniformly and efficiently a coating solution on a single wafer type coating substrate such as a large glass substrate or a plastic substrate. The present invention relates to a coating apparatus and a coating method for coating.
[0002]
[Prior art]
In general, a spin coating method is often used as a method of applying a coating solution on a large glass substrate used in a color filter for LCD (liquid crystal display).
[0003]
There are two types of spin coating methods: the open air type and the closed cup type. In either method, the use efficiency of the coating material is as low as about 10%, and the coating film thickness at the rotation center portion and peripheral portion of the substrate to be coated is low. There is a drawback that it is too thick compared to the middle part. For this reason, for example, when the coating film thickness is required to be in the range of several μm ± 3%, it is difficult to use the coating film formed by the spin coating method as it is. It is necessary to use only the intermediate portion between the peripheral portion and the peripheral portion and the portion having a relatively uniform coating film thickness. That is, the spin coating method has problems in terms of the amount of coating solution used and the effective use of the substrate to be coated.
[0004]
As a method for solving such a drawback of the spin coating method, a knife coating method, a roll coating method, and the like have been proposed. Both the knife coating method and the roll coating method are methods in which a coating clearance is provided on the substrate to be coated, and the coating film thickness is determined by the set value to obtain the smoothness of the coating surface. It is a drawback that it is difficult to obtain a uniform film thickness when the smoothness (roughness degree) of the surface of the coated substrate is lower than the coating accuracy (higher unevenness degree).
[0005]
Therefore, it is possible to eliminate the disadvantages of the respective coating methods as described above, and to form a uniform coating film in a stable state without being affected by the physical properties of the coating solution on the single-wafer type substrate to be coated. As a method, a die coating method, an extrusion coating method, and a bead coating method have been proposed (see Japanese Patent Application No. 05-146757).
[0006]
As a coating apparatus based on these coating methods, for example, a coating liquid is discharged from a coating nozzle onto a substrate to be coated with a certain coating clearance, and at the same time, the substrate to be coated is slid (moved) at a constant speed. By this, what forms a coating film on a to-be-coated substrate is known. At this time, the application liquid is continuously supplied to the application nozzle from the application liquid supply mechanism, and the discharge amount of the application liquid discharged from the application nozzle is kept constant. In addition, when a coating film is formed on a to-be-coated substrate, a fixed amount of beads are formed between the coating nozzle and the to-be-coated substrate, and a certain amount thereof is applied to the to-be-coated substrate.
[0007]
Then, in the above-described conventional coating apparatus, when the application of the coating liquid to the substrate to be coated 8 is finished, the substrate to be coated 8 is located in the vicinity of the end side end portion 8b of the substrate to be coated 8, as shown in FIG. Is stopped relative to the coating nozzle 5, and after the discharge of the coating liquid from the coating nozzle 5 is stopped, the coating nozzle 5 is retracted upward.
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional coating apparatus, when the application of the coating liquid to the substrate to be coated 8 is terminated, the coating nozzle 5 and the substrate to be coated 8 are disposed in the vicinity of the end portion 8b of the substrate to be coated 8. Since the relative movement is stopped, even if the discharge of the coating liquid from the coating nozzle 5 is stopped, the coating liquid between the coating nozzle 5 and the substrate to be coated 8 is disposed at the coating end point of the substrate to be coated 8. Most of the (beads) will remain. That is, in the vicinity of the end 8b of the substrate 8 to be coated, a coating liquid of an amount equal to or larger than the amount of coating liquid applied in a steady state remains on the substrate 8 to be coated. There is a problem that the thickness becomes a defective portion deviating from a normal value.
[0009]
The present invention has been made in consideration of such points, and reduces the film thickness defect portion of the coating film formed at the end of the coating film formation on the substrate to be coated, such as a large glass substrate or a plastic substrate. An object of the present invention is to provide a coating apparatus and a coating method capable of uniformly and efficiently coating a coating liquid on a single-wafer type substrate to be coated.
[0010]
[Means for Solving the Problems]
As a first solution, the present invention provides a coating apparatus for coating a coating liquid on a substrate to be coated, the coating nozzle for discharging the coating liquid, and the coating with the coating nozzle facing the substrate to be coated. A moving mechanism that relatively moves the nozzle and the substrate to be coated; and a coating liquid supply mechanism that supplies a coating liquid to the coating nozzle. The moving mechanism includes a coating liquid in a coating region of the substrate to be coated. The coating nozzle and the substrate to be coated are relatively moved so that the coating nozzle and the substrate to be coated are moved beyond the end of the coating area of the substrate to be coated when the coating on the substrate to be coated is completed. There is provided a coating apparatus characterized by continuing relative movement with a coating substrate.
[0011]
In the first solving means described above, it is preferable to further include a coating liquid stopping mechanism that stops the discharge of the coating liquid from the coating nozzle in the vicinity of the end of the coating area of the substrate to be coated. Further, it is preferable to use a substrate for a color filter as the substrate to be coated and use a colored liquid for a color filter as the coating solution.
[0012]
As a second solution, the present invention provides a coating solution in a coating region of a substrate to be coated, in a coating method in which a coating nozzle and a substrate to be coated are relatively moved to apply a coating solution on the substrate to be coated. So that the coating nozzle and the substrate to be coated are moved relatively so that the coating liquid is applied to the substrate to be coated, and at the end of coating the substrate to be coated And a step of continuing relative movement between the coating nozzle and the substrate to be coated beyond the end of the coating region of the substrate to be coated.
[0013]
Note that the second solving means described above preferably further includes a step of stopping the discharge of the coating liquid from the coating nozzle in the vicinity of the end of the coating region of the substrate to be coated. Further, it is preferable to use a substrate for a color filter as the substrate to be coated and use a colored liquid for a color filter as the coating solution.
[0014]
According to the present invention, when the application to the substrate to be coated is finished, the relative movement between the coating nozzle and the substrate to be coated is continued beyond the end of the coating region of the substrate to be coated. A uniform coating film having a desired film thickness is formed on the entire surface of the substrate to be coated without causing a problem that most of the coating liquid (bead) between the coating nozzle and the substrate to be coated remains at the end point. A uniform coating film having a desired film thickness can be formed even on a large area substrate such as a glass substrate used in a color filter for LCD.
[0015]
Further, according to the present invention, by stopping the discharge of the coating liquid from the coating nozzle in the vicinity of the end of the coating region of the substrate to be coated, the coating nozzle and the substrate to be coated are passed beyond the end of the coating region of the substrate to be coated. When the relative movement is continued, it is possible to prevent the coating liquid from being discharged, and to prevent problems such as the dropping of the coating liquid from the coating nozzle.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 (a), 2 (b), and 2 (c) are diagrams for explaining an embodiment of a coating apparatus according to the present invention.
[0017]
As shown in FIG. 1, the coating apparatus according to the present embodiment applies a coating liquid onto a substrate 8 to be coated, and includes a coating nozzle 5 that discharges the coating liquid.
[0018]
The coating nozzle 5 has a belt-like slit 5a extending in a direction (direction perpendicular to the paper surface in FIG. 1) perpendicular to the slide (moving) direction (left-right direction in FIG. 1) of the stage 3 on which the substrate 8 to be coated is placed. The coating liquid supplied from the coating liquid supply mechanism 18 can be discharged downward through the slit 5a. A coating liquid stopping mechanism 19 is connected to the coating liquid supply mechanism 18, and discharge of the coating liquid from the coating nozzle 5 is stopped by stopping the supply of the coating liquid from the coating liquid supply mechanism 18 to the coating nozzle 5. Can be stopped. As the coating liquid supply mechanism 18, a pressure supply device, a magnet pump, a gear pump, a diaphragm pump, a plunger pump, or the like can be used. Further, as the coating solution stopping mechanism 20, a direct acting solenoid valve, an external pilot valve or the like can be used.
[0019]
The application nozzle 5 is supported by a die holder 4 that can adjust the horizontal state of the application nozzle 5 with respect to the substrate 8 to be applied. The die holder 4 is attached to the support column 16 via an elevating mechanism 15 so that the height of the coating nozzle 5 relative to the substrate to be coated 8 can be arbitrarily adjusted. The support column 16 is fixed on the base 1.
[0020]
On the other hand, the substrate 8 to be coated is placed on the stage 3 through the substrate holder 6 and is held by vacuum suction on the upper surface of the substrate holder 6. The stage 3 is slidably (moved) on the base 1 via an air slide linear motor (moving mechanism) 2, with the slit 5 a of the coating nozzle 5 facing the substrate 8 to be coated. The coating nozzle 5 and the substrate to be coated 8 can be moved relative to each other. Note that a control device 19 is connected to the air slide linear motor 2, and under the control of the control device 19, it is within the coating region (from the start side end 8a to the end side end 8b) of the substrate 8 to be coated. The coating nozzle 5 and the substrate to be coated 8 are moved relative to each other so that the coating liquid is applied, and at the end of coating on the substrate to be coated 8, the end 8b of the substrate to be coated 8 (coating of the substrate to be coated 8) is applied. The relative movement between the coating nozzle 5 and the substrate to be coated 8 can be continued beyond the end of the region. A control device 19 is also connected to the coating solution supply mechanism 18 and the coating solution stop mechanism 20 so that the coating solution is discharged from the coating nozzle 5 onto the substrate to be coated 8 under the control of the control device 19. The coating liquid is continuously supplied from the coating liquid supply mechanism 18 to the coating nozzle 5 and the discharge of the coating liquid from the coating nozzle 5 is stopped in the vicinity of the end 8b of the substrate 8 to be coated. The stop mechanism 20 can stop the supply of the coating liquid from the coating liquid supply mechanism 18 to the coating nozzle 5.
[0021]
As the substrate 8 to be coated, an arbitrary substrate such as a glass substrate used in a color filter for LCD can be used. Moreover, as a coating liquid discharged from the coating nozzle 5, arbitrary things, such as a coloring liquid for color filters, can be used. Specifically, for example, a solvent-based photosensitive resin, a water-based photosensitive resin, or a colored photosensitive resin in which a coloring material such as a pigment is dispersed in these photosensitive resins, various adhesives, a protective film, etc. Resins and various inks can be used.
[0022]
Next, the operation of the present embodiment having such a configuration will be described.
[0023]
First, as shown in FIG. 1, the substrate 8 to be coated is held by vacuum suction on a substrate holder 6 disposed on the stage 3, and the coating nozzle is disposed above the start side end portion 8 a of the substrate 8 to be coated. The position of the stage 3 in the left-right direction is adjusted so that the five slits 5a come. At this time, the parallelism and height of the coating nozzle 5 with respect to the substrate 8 to be coated are adjusted by the die holder 4 and the lifting mechanism 15, respectively.
[0024]
In this state, under the control of the control device 19, the coating liquid is continuously supplied from the coating liquid supply mechanism 18 to the coating nozzle 5, and the coating liquid is discharged downward from the slit 5 a of the coating nozzle 5.
[0025]
At the same time, under the control of the control device 19, the stage 3 is slid leftward from the position of FIG. 1 by the air slide linear motor 2, and the coating liquid discharged from the coating nozzle 5 is applied onto the substrate 8 to be coated. The air slide linear motor 2 is controlled by the control device 19 at the end of application to the substrate 8 to be coated, beyond the end 8b of the substrate 8 to be coated, The relative movement is continued (FIGS. 2A, 2B, and 2C). At this time, the control device 19 controls the coating liquid stopping mechanism 20 to stop the discharge of the coating liquid from the coating nozzle 5 in the vicinity of the end side end portion 8b of the substrate 8 to be coated. Then, the supply of the coating liquid to the coating nozzle 5 is stopped (FIG. 2 (b)).
[0026]
Thereafter, after coating the coating liquid over the entire surface of the substrate 8 to be coated in this way, the stage 3 is slid to the right in FIG. 1 by the air slide linear motor 2 under the control of the control device 19. Return to position.
[0027]
As described above, according to the present embodiment, when the application to the substrate to be coated 8 is finished, the relative movement between the coating nozzle 5 and the substrate to be coated 8 is continued beyond the end portion 8b of the substrate to be coated 8. Therefore, the desired film thickness does not occur without causing a problem that most of the coating liquid (bead) between the coating nozzle 5 and the substrate to be coated 8 remains at the coating end point of the substrate to be coated 8. A uniform coating film having a desired film thickness can be formed on the entire surface of the substrate 8 to be coated, and even on a large area substrate such as a glass substrate used in a color filter for LCD. A coating film can be formed.
[0028]
Further, according to the present embodiment, the discharge of the coating liquid from the coating nozzle 5 is stopped in the vicinity of the end side end portion 8b of the substrate to be coated 8, so that the end side end portion 8b of the substrate to be coated 8 is exceeded, When the relative movement between the coating nozzle 5 and the substrate to be coated 8 is continued, the coating liquid is prevented from being discharged, causing problems such as dropping of the coating liquid from the coating nozzle 5. Can be prevented.
[0029]
In the above-described embodiment, the coating nozzle 5 is fixed in a state where the slit 5a is opened downward, and the stage 3 is slid with respect to the fixed coating nozzle 5 to apply the substrate 8 to be coated. However, the present invention is not limited to this. (1) The application nozzle 5 is fixed in a state where the slit 5a is opened upward, and the stage 3 is attached to the fixed application nozzle 5. (2) The coating nozzle 5 with the slits 5a opened downward is slid with respect to the fixed stage 3 to slide the coating substrate 8. (3) The application nozzle 5 with the slit 5a opened upward is slid with respect to the fixed stage 3, and the application to the application substrate 8 is performed. May be.
[0030]
In the above-described embodiment, the discharge of the coating liquid from the coating nozzle 5 is stopped in the vicinity of the end side end portion 8b of the substrate to be coated 8, but the outside of the end side end portion 8b of the substrate to be coated 8 is stopped. In the case where a coating liquid recovery tank or the like is provided, the coating nozzle 5 and the substrate to be coated are directly stopped without stopping the discharge of the coating liquid from the coating nozzle 5 in the vicinity of the end side end portion 8b of the substrate 8 to be coated. It is also possible to continue the relative movement with respect to 8.
[0031]
【Effect of the invention】
As described above, according to the present invention, the defective film thickness portion of the coating film formed at the end of the coating film formation on the substrate to be coated is reduced, and a single wafer type substrate such as a large glass substrate or a plastic substrate is reduced. A coating liquid can be uniformly and efficiently applied on a coating substrate.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of a coating apparatus according to the present invention.
FIG. 2 is a view for explaining an operation at the end of coating in the coating apparatus shown in FIG. 1;
FIG. 3 is a view for explaining an operation at the end of coating in a conventional coating apparatus.
[Explanation of symbols]
1 Base 2 Air slide linear motor (movement mechanism)
3 Stage 4 Die holder 5 Coating nozzle 5a Slit 6 Substrate holder 8 Substrate 15 Lifting mechanism 16 Support column 18 Coating liquid supply mechanism 19 Controller 20 Coating liquid stop mechanism

Claims (2)

In a coating apparatus for coating a coating solution on a substrate to be coated,
An application nozzle for discharging the application liquid;
A moving mechanism for relatively moving the coating nozzle and the substrate to be coated with the coating nozzle facing the substrate to be coated;
A coating solution supply mechanism for supplying a coating solution to the coating nozzle;
A coating liquid stopping mechanism for stopping the discharge of the coating liquid from the coating nozzle in the vicinity of the end of the coating area of the substrate to be coated;
The moving mechanism relatively moves the coating nozzle and the substrate to be coated so that a coating liquid is applied in a coating region of the substrate to be coated, and at the end of coating the coating substrate, While maintaining the height of the coating nozzle that stopped discharging constant, the relative relationship between the coating nozzle and the substrate to be coated in the state where the discharge of the coating liquid was stopped beyond the end of the coating region of the substrate to be coated Continue to move ,
A coating apparatus using a substrate for a color filter as the substrate to be coated, and a color liquid for a color filter as the coating liquid . In the coating method of coating the coating liquid on the substrate to be coated by relatively moving the coating nozzle and the substrate to be coated,
The step of applying the coating liquid discharged from the coating nozzle onto the substrate to be coated while relatively moving the coating nozzle and the substrate to be coated so that the coating liquid is applied in the coating region of the substrate to be coated. When,
Stopping the discharge of the coating liquid from the coating nozzle in the vicinity of the end of the coating region of the substrate to be coated;
State in which the at the end application to the substrate to be coated while maintaining the height of the coating nozzle has stopped discharge of the coating solution to be constant, beyond the end of the application region of the substrate to be coated, has stopped discharge of the coating liquid the coating nozzle and a step of continuing the relative movement between the substrate to be coated, only free,
A coating method, wherein a substrate for a color filter is used as the substrate to be coated, and a coloring liquid for a color filter is used as the coating solution .

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