JP2962753B2 - Coating method and coating device for viscous liquid - Google Patents

Description

The present invention relates to the application of a viscous liquid capable of forming a thin and uniform coating film with a small amount of a viscous liquid on an application surface of an application object having a relatively large application area. The present invention relates to a method and a coating apparatus.

[Conventional technology]

Conventionally, a photosensitive resin film such as a water-soluble photosensitive resin or a pigment-dispersed photosensitive resin is formed on a relatively large-sized (150 × 150 mm or more) square substrate used for LCD color filters and color image sensors. As a method for performing this, a spin coating method in which the photosensitive resin is dispersed over the entire surface of the substrate by centrifugal force and a roll coating method in which the photosensitive resin is transferred by a roll have been known.

[Problems to be solved by the invention]

FIG. 24 and FIG. 25 are diagrams for explaining the problems of the conventional spin coating method and roll coating method.

By the conventional spin coating method, relatively large size (300
An example in which a photosensitive resin film having a film thickness of 1.0 μm ± 3% is formed on a substrate of (× 320 × 1.1 ^t mm) (FIG. 24A).

FIG. 24B is a graph showing the results of measuring the film thickness on the lattice, and FIG. 24C is a graph of measuring the film thickness continuously between base points AB. As can be seen from these graphs, in the spin coating method, since the substrate is sucked by the spin chuck, the substrate in the sucking portion bends, so that the coating thickness increases at the sucked portion, and chuck unevenness (a) occurs. The chuck unevenness (a) is obtained by forming a plurality of small-size color filters and the like on a large-sized substrate by multi-layering.
When this is cut and used, it does not have a significant effect on the quality of the color filter,
When a large-size LCD color filter having a screen size of 10 to 14 inches is formed, the brightness and density of the screen become uneven, and it is difficult to avoid such unevenness.

In addition, a fringe (b) in which the photosensitive resin is raised around the periphery of the substrate is formed, and there has been a problem that the adhesiveness is deteriorated at the time of exposure.

Further, when the photosensitive resin is dropped on the substrate by the dropping nozzle, the film thickness at that portion becomes thick, that is, so-called dropping unevenness may occur.

Furthermore, in the case of a solvent-based photosensitive resin (OFPR-800), 10 to 15 g / s (sheet) of the photosensitive resin is consumed, and in the case of a water-soluble photosensitive resin, the amount depends on the color to be formed. Consume 80-120 g / s of photosensitive resin. Of these, the photosensitive resin applied to the substrate is 2 of the dropped photosensitive resin.
~ 3%, expensive photosensitive resin cannot be used effectively,
There was a problem that the material cost was high.

On the other hand, by the conventional roll coating method,
When a photosensitive resin film is formed with a film thickness of 1.0 μm ± 10% (Fig. 25A), when the solvent-based photosensitive resin is applied, the photosensitive resin is 5 g / s, which is lower than that of the spin coating method. Requires less application amount. However, streak-like unevenness (c) occurs in the roll application direction (arrow E). FIG.25B is a graph showing the result of measuring the film thickness on the lattice, and FIG.
The figure is a graph in which the film thickness is continuously measured between the base points C and D, and streak-like unevenness (c) is recognized from these graphs. The streak-like unevenness (c) occurs regardless of the type of the photosensitive resin. For this reason, the thickness variation of the coating film formed on the substrate plane becomes ± 10% or more and cannot be used as a filter for a high-quality display.

Japanese Patent Application Laid-Open No. 63-246820 discloses a method for applying a photosensitive resin on a flat object, first, applying the photosensitive resin on the flat object with a roll coater, and then continuing the flat object. A method of applying the photosensitive resin by rotating the photosensitive resin at a predetermined number of revolutions is disclosed.

Japanese Patent Application Laid-Open No. 63-313159 discloses a resist coating section having a transfer roller for applying a resist, a holding device provided to face the transfer roller, and holding a substrate horizontally and rotatable, A moving unit that relatively moves the holding device and the resist coating unit to move the moving roller to the coating surface of the substrate, and a rotating device that rotates the holding device holding the coated substrate. With
An apparatus is disclosed.

Before performing the spin coating method, the method and the apparatus are all intended to apply the photosensitive resin by a roll coating method. However, as described above, the line-shaped unevenness generated by the roll coating method is caused by a roll. It is fixed during coating, and cannot be smoothed even after spin coating. This is the same regardless of what kind of photosensitive resin is applied to what thickness. In particular, in the case of a water-soluble photosensitive resin having low viscosity and poor wettability to a substrate,
It cannot be applied by a method including a roll coating method.

An object of the present invention is to solve the above-mentioned problems and to provide a method and an apparatus for applying a viscous liquid capable of reducing the amount of the viscous liquid applied and forming a thin and uniform coating film. .

[Means for solving the problem]

In order to solve the above-mentioned problems, a method for applying a viscous liquid according to the present invention includes the steps of: applying a viscous liquid to an end of a surface to be coated of an object to be coated; And a spin coating step of uniformly dispersing the viscous liquid stretched in the squeegee coating step over the entire surface of the object to be coated by centrifugal force.

Further, in the method for applying a viscous liquid according to the present invention, the first photosensitive resin is dropped on an end portion of a coating surface of an object to be coated, and the first photosensitive resin is dropped on a part or the entire surface of the coating surface. A squeegee coating step of stretching the conductive resin to a predetermined thickness, and a spin coating step of uniformly dispersing the first photosensitive resin stretched in the squeegee coating step over the entire surface of the object to be coated by centrifugal force. After forming the first photosensitive resin pattern by exposure and development in a predetermined pattern, the second photosensitive resin and the coating object and the first photosensitive resin than the squeegee coating step of the first photosensitive resin Coating by the squeegee coating step and the spin coating step with the squeegee interval increased, exposure and development in a predetermined pattern,
The method may include a step of forming a second photosensitive resin pattern on a portion other than the first photosensitive resin pattern.

Further, in the method for applying a viscous liquid according to the present invention, the first photosensitive resin is dropped on an end of a surface to be coated of an object to be coated, and the first photosensitive resin is dropped on a part or the entire surface of the surface to be coated. A squeegee coating step of stretching the conductive resin to a predetermined thickness,
The first photosensitive resin stretched in the squeegee coating step is applied by a spin coating step of uniformly dispersing the entire surface of the object to be coated by centrifugal force by a centrifugal force, and the first photosensitive resin is exposed and developed in a predetermined pattern to form a first photosensitive resin. After forming the photosensitive resin pattern, the squeegee applying step in which the distance between the object to be applied and the squeegee is larger than that of the first photosensitive resin in the squeegee applying step of the first photosensitive resin, and the spin coating. And a second photosensitive resin pattern is formed in a portion other than the first photosensitive resin pattern, and the third photosensitive resin is The photosensitive resin is applied by the squeegee applying step and the spin applying step in which the distance between the object to be applied and the squeegee is larger than that of the photosensitive resin squeegee applying step, and is formed in a predetermined pattern And light developing, the first and second
And forming a third photosensitive resin pattern on a portion other than the photosensitive resin pattern.

At this time, each of the photosensitive resins may be configured to be a water-soluble photosensitive resin.

On the other hand, the viscous liquid coating apparatus according to the present invention moves the coating nozzle unit that drops the viscous liquid to the end of the surface to be coated, and keeps a constant interval with respect to the surface to be coated of the object to be coated,
A squeegee section for extending the dropped viscous liquid to a predetermined thickness, and uniformly dispersing the extended viscous liquid over the entire surface to be coated by fixing the object to be applied and rotating at a high speed. And a spin chuck unit.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings and the like based on embodiments.

FIG. 1 is a block diagram showing an embodiment of a method for applying a viscous liquid according to the present invention.

The method for applying a viscous liquid according to the present invention includes a squeegee coating step 10 and a spin coating step 12.

The squeegee application step 10 is a step of dropping a viscous liquid onto an end of a surface to be coated of an object to be coated, and extending the dropped liquid to a predetermined thickness on a part or the entire surface of the surface to be coated.

In this step, the viscous liquid is previously spread on the application surface with a squeegee, so that even if the amount of the viscous liquid applied in the subsequent step is reduced, the liquid can be uniformly applied.

The viscous liquid may be a liquid having a viscosity of about 10 to 100 cps, such as a solvent-based photosensitive resin, a water-soluble photosensitive resin, or a photosensitive resin in which a coloring material such as a pigment is dispersed in these photosensitive resins. Photosensitive resins, various adhesives, resins for forming a protective film, inks, and the like can be used.

The thickness of the layer applied in this step is 30 μm to 200 μm
It is preferable that the coating be performed on the entire surface of the coating surface, or the coating may be performed only in the range of about 80 to 90% from the center of the coating surface.

By performing the squeegee coating step 10, the viscous liquid is not dropped on the effective portion of the coating surface, so that the drop unevenness does not occur. In addition, since the unevenness in the effective portion of the application surface can be forcibly flattened, the flow of the viscous liquid along the concave portion peculiar to the conventional application method does not occur.

The spin coating step 12 is a step of uniformly dispersing the viscous liquid stretched in the squeegee coating step 10 over the entire surface of the object to be coated by centrifugal force.

In this step, since the viscous liquid is applied in advance,
The scattering amount of the viscous liquid is greatly reduced, the rebound of the viscous liquid is eliminated, and defective projections are reduced.

FIG. 2 is a perspective view showing a first embodiment of a viscous liquid coating apparatus according to the present invention.

The coating apparatus of the first embodiment is roughly divided into a squeegee coating section 14 and a spin coating section 28.

The squeegee application unit 14 includes a mounting table 16, an application nozzle 18, a squeegee, a squeegee cleaning tank 26, and the like.

The mounting table 16 is used for the application object (hereinafter, referred to as “automatically transported”).
This is a table on which the substrate 34 is placed and fixed.

The application nozzle 18 is provided on the left side of the mounting table 16.
The application nozzle 18 is a nozzle for dropping the photosensitive resin 36, and can be moved at a constant speed in the y direction by a moving table 20 that is moved by a DC motor or the like.

The squeegee 22 is provided in the front-rear direction of the mounting table 16. The squeegee 22 is provided with a DC provided on the front side of the mounting table 16.
The moving table 24 moved by a motor or the like can move at a constant speed in the x direction. Further, the squeegee 22 can be moved in the z direction so that the distance between the squeegee 22 and the substrate 34 can be arbitrarily adjusted.

The squeegee washing tank 26 is provided on the right side of the mounting table 16. The squeegee cleaning tank 26 is a tank for washing the squeegee 22 with a cleaning agent and drying the squeegee 22 each time one operation is completed.

The spin coating unit 28 includes a spin chuck 30 and a spin cup.
It consists of 32 mag.

The spin chuck 30 is a portion that holds the substrate by suction and rotates at a high speed. Since the spin chuck 30 employs an outer peripheral portion vacuum suction system, it is possible to prevent chuck unevenness in effective pixels.

The spin cup 32 is a container having a shape for accommodating the photosensitive resin 36 scattered when the spin chuck 30 rotates.

Next, the operation of the viscous liquid application device of this embodiment will be described.
This will be described in more detail with reference to specific production examples.

A substrate having a size of 300 × 320 × 1.1 ^t mm was used as the substrate, and a pigment-dispersed photosensitive resin was used as the photosensitive resin.
This will be described by way of an example of applying m.

When the substrate 34 is transferred onto the mounting table 16, the application nozzle
18 drops 10 to 25 g of the photosensitive resin 36 while moving in parallel with the end face of the substrate 34.

Next, the distance between the squeegee 22 and the substrate 34 is set to 200 μm, and the photosensitive resin 36 dropped on the substrate 34 is spread over the entire surface by moving at a speed of 5 cm / sec.

Substrate 34 coated with photosensitive resin 36 in squeegee coating section 14
Is transferred to the spin coating unit 28 by an automatic transfer device (not shown).

During this time, the squeegee 22 is washed and dried in the squeegee washing tank 26.

The substrate 34 conveyed to the spin coating unit 28 is rotated at 1900 RPM for a few seconds after being attracted to the spin chuck 30.

As a result, an average of 1.3 μm ± 2% within the effective pixels of the substrate 34
Was obtained.

3 and 4 are views showing a second embodiment of the viscous liquid coating apparatus according to the present invention, and FIG. 5 is a diagram for explaining an operation sequence of the second embodiment. is there.

The coating apparatus according to the second embodiment has a squeegee coating section and a spin coating section integrated with each other. This is because, in the apparatus of the embodiment shown in FIG. 2, it takes time for the automatic transfer from the squeegee coating section to the spin coating section, and depending on the type of the photosensitive resin,
This is because they may not be used due to drying, deterioration, and the like.

The photosensitive resin that can be used in the apparatus shown in FIG. 2 includes a water-soluble photosensitive resin (gelatin, casein, etc.), the aqueous solution photosensitive resin in which a pigment is dispersed, and PVA (polyvinyl alcohol).
Aqueous solution, acrylic-based JDS (made by Nippon Synthetic Rubber), acrylic-based CFP (manufactured by Chisso) and the like are listed. As the photosensitive resin that can be used in the apparatus shown in FIG. 3, JSR-703 (made by Nippon Synthetic Rubber) ), OMR-85, OMR-83 (Tokyo Ohka), OFP
R-800, OFPR2 (manufactured by Tokyo Ohka), PVA aqueous solution, JDS (manufactured by Nippon Synthetic Rubber) based on acrylic, CFP based on acrylic
(Made by Chisso) and the like.

A spin chuck 48 is provided in the spin cup 52 so as to be able to move up and down.
The application nozzle 38 and the squeegee 42 are disposed at the position of the rising end of the nozzle.

Next, the detailed structure and operation of the coating apparatus of this embodiment will be described in more detail according to the operation sequence shown in FIG.

An example will be described in which glass of 300 × 320 × 1.1 ^t mm is used as the substrate 56, and a pigment-dispersed photosensitive resin is applied as the photosensitive resin 58 to a thickness of 1.3 μm.

First, the spin chuck 48 is raised (fifth step).
Figure (d).

While moving table 40 of the dropping nozzle 38 is moved (FIG. 5 _{(a): t 1 ~t 4} ), the photosensitive resin 58 is dropped along the end face of the substrate 56 from dropping nozzle 38 (FIG. 5 (b ): t ₂ ~
t _3).

Next, a squeegee 42 is moved at a constant speed (5 cm / sec), the photosensitive resin 58 on the substrate 56 stretching over the entire surface (FIG. 5 _{(c): t 5 ~t 8} ). At this time, the squeegee 42 and the substrate 56
Is set to 200 μm.

It was coated with a squeegee 42, after lowering the spin chuck 5 in the skin cup 6 (FIG. 5 (d): t ₉ ~
t _10), the spin motor 50 rotates at a high speed 1900 rpm (FIG. 5 _{(f): t 18 ~t 19} ), thereafter, rotates medium speed at 500 RPM (FIG. 5 (f): t ₂₀ ~t ₂₁ ). Thus, since the acceleration time is adopted short spin method is less than 1 second (t ₁₇ ~t _18), never fringe occurs within 10mm of the outer peripheral portion of the substrate.

During this time, the exhaust fan 54 rotates and the chuck cup 52
And evacuating the inner (FIG. 5 _{(e): t 13 ~t 16} ). As described above, the air was evacuated from the spread and the diameter of the upper hood was increased (from φ10 cm to φ30 cm), so that the airflow slipped on the substrate surface and the thickness difference did not occur. The squeegee 42 is cleaned in a squeegee cleaning tank 46,
Is dried (FIG. 5 _{(h): t 27 ~t 30} ).

Substrate 56 on which the photosensitive resin 58 is uniformly applied is unloaded from the spin cup 52 by a transfer arm (not shown) (FIG. 5 _{(g): t 23 ~t 26} ).

As a result, an average of 1.3 μm ± 2.0
% Of the photosensitive resin film was obtained.

As described above, according to the present invention, the utilization efficiency of the photosensitive resin (1/4 to 1/5 reduction compared to the related art) is high, and the variation in the film thickness formed on the substrate plane can be suppressed to about ± 2%.

6 to 15 are views showing a third embodiment of the viscous liquid applying apparatus according to the present invention, wherein FIG. 6 is a plan view of a main part, and FIG. 7 is FIG. VII sectional view, FIG.
Fig. VIII-VIII sectional view, Fig. 9 is a plan view showing a part of the spin chuck, Fig. 10 is a side sectional view of Fig. 9, Fig. 11 is a view showing a coating nozzle, Fig. 12 is a squeegee. The figure showing the
13 is a partially enlarged view of the squeegee, FIG. 14 is a partially enlarged view showing a modification of the squeegee, FIG. 15 is a plan view showing a squeegee washing tank, and FIG. 16 is a side cross section of the squeegee washing tank. FIG.

The coating apparatus according to the third embodiment has an integrated squeegee coating section and a spin coating section as in the apparatus according to the second embodiment, but has an improved structure in detail.

This coating apparatus basically includes a spin chuck 60 that fixes the substrate 74 by vacuum and spins a spin, a coating nozzle 60 that drops a photosensitive resin 80 onto an end of the substrate, and a photosensitive drum that is dropped. A squeegee 90 that stretches the resin 80 over the entire surface of the substrate, a squeegee cleaning unit 124 that cleans the squeegee 90 to which the photosensitive resin 80 has adhered, and a photosensitive resin that has adhered to the outer periphery of the spin chuck 60 and around the spinner cup 62 by a coating process. Chuck cleaning nozzle 14 that drops 80
0,142 and so on.

As shown in FIG. 7 and FIG.
It is provided in the spinner cup 62. The spin chuck 60 has a motor shaft 64 as shown in FIGS.
, Chuck receiver 66, chuck lower part 68, and chuck middle part
70 and an upper portion 72 of the chuck. In addition,
9 and 10 show a substantially quarter portion of the spin chuck 60, further omitting an intermediate portion in the left-right direction. The motor shaft 64 has a large-diameter passage 64a and a small-diameter passage 64b.
Is provided. The chuck receiver 66 has a disk portion 66b provided on a cylindrical portion 66a, and further has a convex portion 66c on the disk provided thereon.
The inner wall of the cylindrical portion 66a is inserted into the upper end of the motor shaft 64. This chuck receiver 66
A passage 66d connected to a passage 64a of the motor shaft 64, and a passage 64b
66e connected to the passage 66e, and an annular passage communicating with the passage 66e.
66f and four radial passages 66g communicating with the passage 66f. The chuck lower part 68 has a shape in which a side wall 68b is provided on the outer periphery of a square bottom plate 68a, and a coupling hole 68c provided in the center part is coupled to the disk part 66b of the chuck receiver 66. In the middle part 70 of the chuck, a coupling hole 70b provided in the center of the square plate 70a is coupled to the convex part 66c of the chuck receiver 66, and the plate 70a is inserted into the lower part 68 of the chuck with a gap. The chuck middle part 70 has a convex part 70 on the outer peripheral edge of the upper surface.
c and a cross groove 70d passing through the center of the upper surface. The chuck upper part 72 is mounted in the chuck middle part 70. The substrate 74 is supported by the convex portion 70c on the outer peripheral edge of the middle portion 70 of the chuck.

The passage 64a of the motor shaft 64 is connected to a three-way valve (not shown), and compressed air from an air pressure source or vacuum from a vacuum pump is selectively supplied. The passage 64a communicates with a flow path 66d of the chuck receiver 66, a groove 70d of the chuck middle portion 70, and a gap between the protrusion 70c of the chuck middle portion 70 and the chuck upper portion 72.
When the spin chuck 70 and the spinner cup 72 are cleaned, compressed air is supplied to prevent the cleaning liquid from entering. The passage 64b of the motor shaft 64 is supplied with compressed air from an air pressure source. The passage 64b communicates with the passage 66e, the passage 66f, the passage 66g of the chuck receiver 66, and the gap between the chuck lower part 68 and the chuck middle part 70, and prevents the infiltration of the photosensitive resin by the compressed air when the photosensitive resin is applied. .

The coating nozzle 76 can move at an arbitrary speed along the guide rod 78 as shown in FIGS. 6 and 11, and the photosensitive resin 80 is dropped on the end of the substrate 74. In this embodiment, the application nozzle 76
Is set to about 100 mm / sec.

The sensors 82, 84, 86, and 88 are provided outside the application nozzle 76, and detect the application nozzle 76 in a non-contact manner. Sensor 82
By delaying the output of the sensor 84 with a timer,
It is used as a signal for determining the timing of starting and ending the discharge of the photosensitive resin 80. Further, the moving speed of the coating nozzle 76 is determined between the sensors 82 and 84, between the sensors 84 and 86, and between the sensors 84 and 86.
It can be changed between 86 and 88.

The squeegee 90 is a photosensitive resin dropped on the edge of the substrate 74.
This is for extending 80 over the entire surface of the substrate 74.
As shown, it can move along guide rods 92,94.

The squeegee 90 of this embodiment is designed to maintain the reproducibility of the gap amount even if the thickness of the substrate 74 varies. As shown in FIGS. 12 and 13, the squeegee 90 has a larger radius at both ends of the columnar squeegee portion 96 than the radius of the squeegee portion 96 by a predetermined gap amount δ to prevent wear. Teflon-coated guides 98 for
Is provided. The squeegee 90 is moved by the guide portion 98 directly contacting both ends of the board 74.
A predetermined gap amount δ can be provided between 74.

If the weight of the squeegee 90 applied to both ends of the substrate 74 is heavy, the substrate 74 may bend and the gap amount may fluctuate. Therefore, the structure is as follows. As shown in detail in FIG. 13, a shaft 100 is provided further outside the guide portion 98 of the squeegee 90. A support rod 104 is provided in the receiving portion 102 that moves on the guide rod 94, and the support rod 104 is provided.
An arm 106 is provided at 104. The arm 106 has an elongated hole 106a for allowing play in the direction of the arrow, and the shaft 100 is inserted into the elongated hole 106a. For this reason, the weight applied to both ends of the substrate 74 is only the squeegee portion 96, the guide portion 98, and the shaft 100, and the substrate 74 is bent and the gap amount δ
Will not fluctuate.

Further, the squeegee 90 may have a structure as shown in FIG. 14 for the same purpose. Shafts 112 are provided on both sides of a guide portion 110 provided on the squeegee portion 108.
, A shaft 116 is provided in a crank shape. This axis 116
It is supported by an arm 118, and the other end of the shaft 116 is provided with a weight 122 via an arm 120 so as to be balanced with the squeegee part 108.
Is provided.

The squeegee cleaning section 124 is disposed on the opposite side of the application nozzle 76 across the spinner cup 62, as shown in FIGS. 6, 15, and 16. The cleaning liquid 126 is supplied to the cleaning tank 126 from a water supply pipe 126a, and is drained from a drain pipe 126b.
A cleaning brush 130 made of nylon is rotatably arranged in the cleaning tank 126. A roller unit is disposed diagonally above the cleaning tank 126. The roller unit includes a squeezing roller 132 and a wiping roller
To enable the wiping roller 134 to rotate about the axis of the squeezing roller 132. The cleaning tank 126, the squeezing roller 132, the wiping roller 134, and the like are further covered with an outer case 138, and the cleaning liquid 128 overflowing from the cleaning tank 126 is drained from a drain pipe 138a.

After finishing the squeegee application, the squeegee 90
Move to position 126. When the squeegee section 96 moves to the upper part of the cleaning tank 126, the cleaning brush 130 cleans the squeegee section 96 to which the photosensitive resin 80 has adhered. Next, the squeegee section
96 rises and the wiping roller 134 rotates 90 degrees to wipe the surface of the squeegee section 96. In addition, the wiping roller 134
Is wiped while being squeezed by the squeezing roller 132. During this time, drain the inside of the cleaning tank 126,
The cleaning liquid is replaced by the water supply valve.

The chuck cleaning nozzles 140 and 142 are provided on the coating nozzle 76 side in the spinner cup 62, as shown in FIGS. These chuck cleaning nozzles 140, 142
The cleaning liquid (for example, pure water) is discharged onto the spin chuck 60, and at the same time, the spin chuck 60 rotates, and the centrifugal force causes the photosensitive resin adhered to the outer periphery of the spin chuck 60 and around the spinner cup 62 to be removed. Cleaning is performed so as to remove them.

The tacts 144 and 146 are for carrying the substrate 74 into and out of the spin chuck 60 in the spinner cup 62 as shown in FIGS. 6 and 8, and in this embodiment, both sides of the spinner cup 62 are used. The first tact 144A, 146A and the second tact
The tacts 144B and 146B are arranged, and loading and unloading are performed alternately to improve efficiency.

17 and 18 are diagrams for explaining the characteristics of the third embodiment of the viscous liquid coating device according to the present invention,
FIG. 17 is a diagram showing the relationship between the gap amount between the substrate and the squeegee and the minimum amount of the photosensitive resin dropped, and FIG. 18 is a diagram showing the relationship between the squeegee feed speed and the minimum amount of the photosensitive resin dropped.

In order to increase the effective utilization rate of the photosensitive resin, it is necessary to find the minimum amount of the photosensitive resin that can be uniformly applied to the entire surface of the substrate.

When the size of the substrate is 300 × 320 × 1.1 ^t mm and the elemental glass is used (solid line) and when the chrome pattern which is a light shielding layer for improving the contrast is provided on the surface of the elemental glass (dotted line) About pigment-dispersed water-soluble photosensitive resin (BL
UE), the following test was performed.

When the feed rate of the squeegee is constant (73 mm / sec) and the gaps between the substrate and the squeegee are 0.10 mm, 0.15 mm, and 0.20 mm, the minimum amount of photosensitive resin required to be dropped is measured.
The results shown in Fig. 17 were obtained. In this embodiment, utilizing this result, the drop amount of the photosensitive resin is determined based on the gap amount between the substrate and the squeegee.

Next, the gap between the substrate and the squeegee was 0.10 mm, 0.1
When the distance was 5 mm or 0.20 mm, the minimum drop amount of the photosensitive resin was measured by changing the speed of the squeegee. As shown in FIG. 18, when the feed speed of the squeegee is decreased, the minimum drop amount of the photosensitive resin is reduced. In addition, it can be seen that, at a feed rate of 40 mm / sec or more for each gap amount, application can be performed stably with a substantially constant drop amount regardless of the feed speed of the squeegee. In the coating apparatus of this embodiment, the feed speed of the squeegee was set to about 60 mm / sec in consideration of throughput (mass productivity) and coating stability.

FIG. 19 is a process diagram for explaining a coating process of a third embodiment of the viscous liquid coating device according to the present invention.

This process diagram is based on the timing at the time of sensor output, and the white arrow in the diagram indicates that the device is moving.

First tact 144A, 146A is moved from the intermediate position to the wash chamber position (Fig. 19 _{(a): t 1 ~t 2} ), to move from the arm upper limit position shown in FIG. 8 to the arm lower limit position (second 19 view _{(a): t 3 ~t 4} ), by closing the arm (Fig. 19 _{(a): t 5 ~t 6} ), grab substrate 74 wash chamber. Then, the arm is moved from the lower limit position to the upper limit position (Fig. 19 _{(a): t 7 ~t 8} ), moved from the washing chamber position to the coater chamber position (Fig. 19 (a): t ₉ ~t _10), the arm is moved from the upper position to the lower limit position (Fig. 19 (a): t ₁₁ ~
At t ₁₂ ), the arm is opened (FIG. 19A: t _{13 to} t ₁₄ ), and the substrate 74 is placed on the spin chuck 60. Furthermore, the arm moves from the lower limit position to the upper limit position (Fig. 19 (a): t ₁₅ ~t
_16), and waits moves from the coater chamber located in an intermediate position (Fig. 19 _{(a): t 17 ~t 18} ).

The application nozzle 76 detects the timing at which the first tacts 144A and 146A move from the washing chamber position to the coater chamber position (first timing).
19 view (a): in synchronism with the t _10), a predetermined time performing discharging of the photosensitive resin (Fig. 19 _{(c): t 19 ~t 20} ). Next, the arm moves from the origin position to the end point position shown in FIG. 6 in synchronization with the timing at which the arm moves from the lower limit position to the upper limit position (FIG. 19A: t ₁₆ ) (FIG. 19C). : t _{21 to} t
₂₂₎ At this time, a predetermined time performing discharging of the photosensitive resin (Fig. 19 _{(c): t 23 ~t 24} ). Thereafter, returning from the end position to the home position (Fig. 19 _{(c): t 25 ~t 26} ).

Squeegee 90, the output from the sensor for detecting the position of the coating nozzle 76 is moved to the end position from the home position shown in FIG. 6 (Fig. 19 _{(d): t 27 ~t 28} ). At this time, the squeegee 90 is moved from the lower limit position to the upper limit position (Fig. 19 _{(d): t 29 ~t 30} ). Then go to the end point from the coating end position (Fig. 19 _{(d): t 31 ~t 32} ), moves from the upper position to the lower limit position (Fig. 19 _{(d): t 33 ~t 34} ).

Spin motor, the timing of the squeegee 90 is moved to the end point (Fig. 19 (d): t ₃₂₎ in synchronism with the motor lock is released, it becomes free (Fig. 19 (e): t ₃₅ ~
t _36). At the same time, spinner cup 62 moves from the lower limit position to the upper limit position (Fig. 19 _{(f): t 37 ~t 38} ). After the spin motor is turned on and off according to a predetermined spin program (FIG. 19 (e): t _{39 to} t ₄₀ ), the spinner cup 6
2 moves from the upper limit position to the lower limit position (FIG. 19 (f): t
₄₃ ~t _44). Spin motor is turned off by the home search (Fig. 19 (e): t _45). Motor becomes a state of being locked from the free state (Fig. 19 _{(e): t 47 ~t 48} ).

When spin coating by the spin motor has been completed, the second tact 144B, 146B is moved from the intermediate position to the coater chamber position (Fig. 19 _{(b): t 49 ~t 50} ), the arm upper limit position shown in FIG. 8 from moving to the arm lower limit position (Fig. 19 _{(b): t 51 ~t 52} ), closing the arm and by (Fig. 19 _{(b): t 53 ~t 54} ), grip the substrate 74 in the coater chamber . Then, the arm is moved from the lower limit position to the upper limit position (Fig. 19 _{(b): t 55 ~t 56} ), moves from the coater chamber located dry chamber position (Fig. 19 (b): t ₅₇ ~t ₅₈ ),
Arm is moved from the upper position to the lower limit position (Fig. 19 _{(b): t 59 ~t 60} ), open the arm (Fig. 19 (b): t ₆₁
~ T ₆₂ ), transfer to substrate 74 to dry chamber. Further, the arm moves from the lower limit position to the upper limit position (FIG. 19 (b): t ₆₃ ).
At t ₆₄ ), it moves from the dry chamber position to the intermediate position and waits (FIG. 19 (b): t _{65 to} t ₆₆ ).

On the other hand, the squeegee 90
Located on 124. Cleaning brush 130 is always rotating, by the squeegee is moved to the lower limit position from the upper position (Fig. 19 _{(d): t 33 ~t 34} ), cleaning is started (the first
Immediately before the end of cleaning (FIG. 9 (g): t ₆₇ ) and the end of cleaning (FIG. 19 (g): t ₆₈ ), the water supply in the cleaning tank 126 is stopped (FIG. 19 (g):
At t ₆₉ ), drainage is started (Fig. 19 (g): t ₇₁ ). Second tact 144B, at a timing 146B is moved into the dry chamber (Fig. 19 (b): t _58), extraction roller is moved from the home position to the end position (Fig. 19 (g): t ₇₅ ~t ₇₆ ), the cleaning liquid on the squeegee 90 is wiped off by the constantly rotating wiping roller, and the squeegee 90 is moved from the end point position to the origin position (No.
19 view _{(g): t 77 ~t 78} ), and ends the wiping. After that, the drainage of the washing tank is completed (FIG. 19 (g): t ₇₂ ), and water supply is started (FIG. 19 (g): t ₇₀ ). Spinner cup 62
After the substrate 74 has been discharged from (Fig. 19 (b): t _58), the spinner cup 62 rises (Fig. 19 _{(e): t 79 ~t 80} ),
The lock of the spin motor becomes free (Fig. 19 (e): t
₈₁ ~t _82), according to the spin program, the spin motor turns (Fig. 19 _{(e): t 46 ~t 83} ~t 84). During this time, the chuck cleaning liquid is injected (Fig. 19 (h): t ₈₉ ~
t ₉₀ ). The spinner cup 62 descends (FIG. 19 (f): t ₈₅
~ T ₈₆ ), the spin motor is locked (FIG. 19 (e):
t ₈₇ ~t _88).

The vacuum of the spin chuck 60 is the first tact 144A, 1
When the substrate 74 enters the coater chamber by 46A (No. 19
From FIG. (A): t ₁₀ ), the substrate 7 is obtained by the second tact 144B and 146B.
When the 4 exits the coater chamber (Fig. 19 (b): t ₅₀₎
(FIG. 19 (i): t _{91 to} t ₉₂ ).

Air of the spin chuck 60, at the start of the spin program when the chuck cleaning (Fig. 19 (e): in synchronization with a t _46, is turned on for a predetermined time (Fig. 19 (i): t ₉₃
~ T ₉₄ ).

The outer peripheral air of the spin chuck 60 is the first tact 144A, 146
When the arm of A moves to the upper limit position (Fig. 19 (a): t
_16), when the second tact 144B, an arm of 146B has moved to the upper limit position (Fig. 19 (b): t ₅₀₎ until being turned (Fig. 19 _{(i): t 95 ~t 96} ). Also, at the start of the spin program when the chuck cleaning (Fig. 19 (e): t ₄₆₎ in synchronism with, and is turned on for a predetermined time (Fig. 19 _{(i): t 97 ~t 98} ) .

One cycle from when the substrate 74 is loaded into the coater chamber to when the above-described process is completed is 80 seconds.

FIG. 20 is a process diagram showing a third embodiment of the viscous liquid applying apparatus according to the present invention, in which a color (color separation) filter is manufactured as an example.

The red, green and blue pigments are dispersed in the photosensitive resin at the composition ratios as shown in Table 1, respectively.
The green and blue colored photosensitive resins 80R, 80G, and 80B are prepared.

The substrate 74 is a 1.1 mm thick glass substrate (Asahi Glass AL
) Was sufficiently washed.

A red photosensitive resin 80R was dropped on the substrate 74 with a dropping nozzle 76 (FIG. 20 (a)), and the gap amount G ₁ between the squeegee 96 and the substrate 74 was set to 0.1 mm, and a squeegee 96 was applied. (FIG. 20 (b)). Furthermore, spin coating is performed, and 1.
The film thickness was set to 2 μm (FIG. 20 (c)). After that, the film was dried in an oven at a temperature of 70 ° C. for 30 minutes, and a mask 150 having a predetermined pattern was brought into close contact therewith, and exposed using a mercury lamp (FIG. 20 (d)). Then, a red relief pixel is formed in a region where a red pixel is to be formed, and further heat-cured at 150 ° C. for 30 minutes to obtain a red relief pixel 80r in a region where a red pixel is to be formed (FIG. 20 (e)). )).

Similarly, dropwise green photosensitive resin 80G gap amount G ₂ of (squeegee 96 and the substrate 74, and the larger the gap amount G ₂ = 0.2 mm than the gap amount G ₁ described above, and squeegee coating squeegee 96 (FIG. 20 (f)) Further, spin coating was performed to make a film thickness of 1.2 μm (FIG. 20 (g)), and then dried in an oven at a temperature of 70 ° C. for 30 minutes. Then, a mask 152 having a predetermined pattern is brought into close contact, exposed using a mercury lamp (FIG. 20 (h)), spray-developed with water for 1 minute, and a green relief pixel is formed in a region where a green pixel is to be formed. The green pixel was formed and cured by heating at 150 ° C. for 30 minutes to obtain a green relief pixel 80 g in a region where a green pixel was to be formed (FIG. 20 (i)).

Further, a blue photosensitive resin 80B, similarly to the green-sensitive resin 80G, After dropwise, and the larger the gap amount G ₃ = 0.2 mm than the gap amount G ₁ described above, and squeegee coating with a squeegee 96 (20th (J), similarly to the green relief image, exposed and developed with a mask having a predetermined pattern, and then heat-cured to obtain a blue relief pixel 80b in a region where a blue pixel is to be formed. .

Finally, apply a transparent resin to a thickness of 2 μm,
To form a protective film, and a color separation filter in which red relief pixels 80r, green relief pixels 80g, and blue relief pixels 80b are regularly arranged was manufactured (FIG. 20 (k )).

Next, the results of application of the viscous liquid coating apparatus of this embodiment (squeegee coating + spin coating) and a conventional spin coating only coating apparatus will be compared.

 First, the effective utilization rates of the photosensitive resins are compared.

As can be seen from Table 2, the effective utilization rate of the red photosensitive resin forming the red pixel is as high as 33.8%, but in the case of the green photosensitive resin forming the green pixel and the blue photosensitive resin forming the blue pixel, The effective utilization rates were both 8.8%. The reason is that, in the LCD manufacturing process, three color pixel patterns are formed on the substrate, respectively.
It can be applied with the gap between squeegees being 0.1 mm. However, since the photosensitive resin of the second color (green pixel) and the photosensitive resin of the third color (blue pixel) must be coated on a substrate on which a 1.2 μm red pixel pattern has already been formed, the gap amount is large. When squeegee coating is performed at a thickness of 0.1 mm and then spin coating is applied, unevenness occurs. Therefore, in order to eliminate this unevenness, the squeegee must be applied with the gap amount set to 0.2 mm. However, it can be seen that the total cost of the photosensitive resin is reduced to about 1/4, and the effective utilization rate is significantly improved.

FIGS. 21 and 22 are diagrams showing the film thickness distribution characteristics of the third embodiment of the viscous liquid coating apparatus according to the present invention in comparison with the conventional example.

In the example shown in FIG. 21, the photosensitive resin is a negative photosensitive resin in which a pigment is dispersed in PVA-stilbazol group,
Those having a viscosity of 40 to 45 cps were used. The substrate is 300
A test was performed using one of × 300 × 1.1 ^t mm.

As a result, it can be seen that the rise of the photosensitive resin at the center of the substrate is significantly reduced in the present invention (FIG. 21A) as compared with the conventional example (FIG. 21B). The in-plane variation in the film thickness is ± 3.5% in the conventional example and ± 3.5% in the present invention in the inscribed surface of φ300 mm.

In the example shown in FIG. 22, the photosensitive resin was a novolak-based positive photosensitive resin having a viscosity of 6 cps, and the test was performed using a substrate of 300 × 300 × 1.1 ^t mm in the same manner. went.

As a result, it can be seen that the rise of the photosensitive resin at the center of the substrate is smaller in the present invention (FIG. 22A) than in the conventional example (FIG. 22B). The in-plane variation of the film thickness is an inscribed circle of φ300 mm, which is within ± 3% in the conventional example, but is within ± 2% in the present invention.

FIG. 23 is a diagram showing the relationship between the amount of photosensitive resin dripped and foreign matter according to a third embodiment of the viscous liquid coating device according to the present invention, in comparison with a conventional example.

When the photosensitive resin is applied under the same conditions as above,
It can be seen that in the conventional example of only spin coating, 30 g or more of the photosensitive resin is required, and the number of foreign substances increases as the amount of the photosensitive resin dropped increases. These foreign substances bring much more photosensitive resin into the spinner cup than the amount of photosensitive resin required for application, and the photosensitive resin is re-adhered to the substrate by being scattered.

In this embodiment, the amount of the photosensitive resin to be dropped is 30 g or less, and the number of foreign substances is hardly recognized.

〔The invention's effect〕

As described in detail above, according to the present invention, the viscous liquid is previously stretched to a predetermined thickness by a squeegee before spin coating, so that the amount of the viscous liquid used is greatly reduced as compared with the conventional viscous liquid usage. be able to. In addition, it is possible to form a thin and uniform coating film over the entire application surface with less variation in film thickness.

Therefore, when an expensive photosensitive resin is applied, the material cost can be significantly reduced.

Further, according to the present invention, since a water-soluble photosensitive resin, which has conventionally been difficult to form a coating film uniformly, can be uniformly applied, a solvent required when a solvent-based photosensitive resin is used. There is no need for a recovery device or the like, which is advantageous for cost reduction.

Further, when a color filter is manufactured according to the present invention, an extremely high-quality color filter free from luminance unevenness and color density unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a method for applying a viscous liquid according to the present invention. FIG. 2 is a perspective view showing a first embodiment of a viscous liquid coating apparatus according to the present invention. 3 and 4 are views showing a second embodiment of the viscous liquid coating apparatus according to the present invention, and FIG. 5 is a diagram for explaining an operation sequence of the second embodiment. is there. 6 to 15 are views showing a third embodiment of the viscous liquid applying apparatus according to the present invention, wherein FIG. 6 is a plan view of a main part, and FIG. 7 is FIG. VII sectional view, Fig. 8 is Fig. 6
VIII-VIII sectional view, FIG. 9 is a plan view showing a part of the spin chuck, FIG. 10 is a side sectional view of FIG. 9, FIG. 11 shows a coating nozzle, and FIG. 12 shows a squeegee. Illustrated figure, thirteenth
FIG. 14 is a partially enlarged view of the squeegee, FIG. 14 is a partially enlarged view showing a modification of the squeegee, FIG. 15 is a plan view showing a squeegee cleaning tank, and FIG. 16 is a side sectional view of the squeegee cleaning tank. It is. 17 and 18 are diagrams for explaining the characteristics of the third embodiment of the viscous liquid coating device according to the present invention, and FIG.
The figure shows the relationship between the gap between the substrate and the squeegee and the minimum amount of the photosensitive resin to be dropped. FIG. 18 shows the relationship between the squeegee feed speed and the minimum amount of the photosensitive resin to be dropped. FIG. 19 is a process diagram for explaining a coating process of a third embodiment of the viscous liquid coating device according to the present invention. FIG. 20 is a process diagram showing a process of manufacturing a color (color separation) filter in the third embodiment of the viscous liquid applying apparatus according to the present invention. FIGS. 21 and 22 are diagrams showing the film thickness distribution characteristics of the third embodiment of the viscous liquid coating apparatus according to the present invention in comparison with the conventional example. FIG. 23 is a diagram showing the relationship between the amount of applied photosensitive resin and the amount of foreign matter according to the third embodiment of the viscous liquid application device according to the present invention, in comparison with a conventional example. FIG. 24 and FIG. 25 are diagrams for explaining the problems of the conventional spin coating method and roll coating method. 10 ... Squeegee coating process, 12 ... Spin coating process 14 ... Squeegee coating unit, 16 ... Placement table 18 ... Coating nozzle, 20 ... Moving platform 22 ... Squeegee, 24 ... Moving platform 26 ... Squeegee Cleaning tank, 28 Spin coating unit 30 Spin chuck 32 Spin cup 34 Substrate 36 Photosensitive resin

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mitsuru Iida 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (56) References JP-A-1-1844073 (JP, A) JP-A-63-296866 (JP, A) JP-A-63-95626 (JP, A) JP-A-63-6218 (JP, A) JP-A-62-186964 (JP, A) (58) Int.Cl. ⁶ , DB name) B05C 11/02-11/08 B05D 1/40 B05D 3/00-3/12 G03F 7/16-7/16 502 H01L 21/027 G11B 5 / 84,7 / 24

Claims (5)

(57) [Claims] A squeegee coating step of dropping a viscous liquid onto an end of a surface to be coated of an object to be coated and stretching the dropped liquid to a predetermined thickness on a part or the entire surface of the surface to be coated; A viscous liquid coating method comprising: a spin coating step of uniformly dispersing the viscous liquid stretched in the squeegee coating step over the entire surface of the object to be coated by centrifugal force. 2. A method according to claim 1, wherein the first photosensitive resin is dropped on an end of the surface to be coated of the object to be coated, and the first photosensitive resin is dropped on a part or the whole of the surface to be coated with a predetermined thickness. A squeegee coating step of stretching the first photosensitive resin and a spin coating step of uniformly dispersing the first photosensitive resin stretched in the squeegee coating step over the entire surface of the object to be coated by centrifugal force to form a predetermined pattern. After forming the first photosensitive resin pattern by exposure and development in the above, the distance between the object to be applied and the squeegee is larger than the second photosensitive resin in the squeegee applying step of the first photosensitive resin. Forming a second photosensitive resin pattern on a portion other than the first photosensitive resin pattern by applying by a squeegee coating process and the spin coating process, and exposing and developing with a predetermined pattern. Method of applying a viscous liquid. 3. A method according to claim 1, wherein the first photosensitive resin is dropped on an end of the surface to be coated of the object to be coated, and the first photosensitive resin is dropped on a part or the whole of the surface to be coated with a predetermined thickness. A squeegee coating step of stretching the first photosensitive resin and a spin coating step of uniformly dispersing the first photosensitive resin stretched in the squeegee coating step over the entire surface of the object to be coated by centrifugal force to form a predetermined pattern. After forming the first photosensitive resin pattern by exposure and development in the above, the distance between the object to be applied and the squeegee is larger than the second photosensitive resin in the squeegee applying step of the first photosensitive resin. Coating is performed by a squeegee coating step and the spin coating step, and is exposed and developed in a predetermined pattern to form a second photosensitive resin pattern in a portion other than the first photosensitive resin pattern. Photosensitivity Grease is applied by the squeegee application step and the spin application step in which the distance between the object to be applied and the squeegee is larger than the squeegee application step of the first photosensitive resin, and is exposed and developed in a predetermined pattern. Forming a third photosensitive resin pattern on a portion other than the first and second photosensitive resin patterns. 4. The method according to claim 2, wherein each photosensitive resin is a water-soluble photosensitive resin. 5. A coating nozzle for dropping a viscous liquid onto an end of a coating surface of an object to be coated, and moving at a constant interval from the coating surface of the coating object to drop the viscous liquid. A squeegee section for extending the viscous liquid to a predetermined thickness, and a spin chuck section for uniformly dispersing the extended viscous liquid on the entire surface of the application surface by fixing the object to be applied and rotating at a high speed. Viscous liquid coating device composed of