JPH11128817A - Chemical solution applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the discharge of a prescribed amt. of a chemical solution which does not contain foreign matter and air bubbles by providing the applicator with bypass piping for bypassing a foreign matter removing filter and disposing stop valves between the branch point on the sucking valve of the bypass piping and the foreign matter removing filter and on the bypass piping. SOLUTION: The piping 7 is provided with the stop valve 8a and the sucking valve 9. The foreign matter removing filter 10 is disposed between the sucking valve 9 and the discharge nozzle 3 and on the piping 7 near the discharge nozzle 3. The bypass piping 11 which connects the piping 7 on the sucking valve 9 side and the piping 7 on the discharge nozzle 3 and bypasses the foreign matter removing filter 10 is disposed. Further, the stop valves 8b, 8c are disposed at the two points between the branch point 12a on the sucking valve 9 side of the bypass piping 11 and the foreign matter removing filter 10 and on the bypass piping 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has at least a pipe for supplying a chemical to a discharge nozzle, and an opening / closing valve provided in the middle of the pipe, and discharges the chemical from the discharge nozzle onto an object to be coated as appropriate. More particularly, the present invention relates to a chemical liquid applying apparatus for discharging and applying a chemical liquid to a glass substrate serving as a color filter for a color liquid crystal display device or a thin metal plate serving as a shadow mask for a color picture tube.

[0002]

2. Description of the Related Art Conventionally, for example, a color filter for a color liquid crystal display device using a transparent substrate such as glass as a material, or a shadow mask used for a color picture tube or the like using a sheet-like metal thin plate as a material has been used. As represented by manufacturing, a chemical solution (coating material) such as a photosensitive resin may be applied to a substrate, for example, a glass substrate or a metal thin plate, with a uniform coating thickness.

That is, after a chemical solution (coating material) such as a photosensitive resin is applied onto a substrate or a thin metal plate (object to be coated), pattern exposure through an exposure pattern mask, development, and hardening are performed. And forming a pattern film made of a coating material according to a predetermined pattern on a substrate. In the manufacture of a color filter, the pattern film is used as a colored pixel, and in the manufacture of a shadow mask, the pattern film is etched on a thin metal plate as an etching-resistant layer, so that a predetermined thickness of the thin metal plate is obtained. An etching pattern is formed in the region.

[0004] Here, as one of means for applying to an object to be applied such as a substrate, for example, a chemical liquid applying apparatus 21 shown in FIG. 4 is known. That is, after a predetermined amount of the chemical solution 6 (coating material) is placed on the substrate (substrate 4) placed substantially horizontally on the mounting table 5, the substrate (coating material) is rotated at a predetermined rotation speed and rotation time. By rotating the object 4), an attempt is made to apply the chemical solution 6 (application material) on the substrate (object 4) to a predetermined thickness on the substrate (object 4) by the generated centrifugal force. Things. FIG. 4 shows only an essential part of an example of the chemical liquid application device 21, and other components of the application device 21, such as a substrate rotating unit, a chamber, and a lid, are omitted for convenience of explanation. Is what it is.

As shown in the above-described example, one of the components of a chemical solution application device (hereinafter simply referred to as an application device 21) for applying a chemical solution 6 (application material) onto an object to be coated 4 includes a substrate. Means for discharging a predetermined amount of the chemical solution 6 (application material) (chemical solution discharging means 22).

As shown in an example of FIG. 4, the chemical liquid discharging means 22 generally has a pipe 7 for supplying the chemical liquid 6 to the discharge nozzle 3 and an opening / closing valve 8 provided in the pipe 7. It can be said that. By supplying a chemical solution 6 (coating material) into the pipe 7 at a predetermined pressure (supply pressure) by a chemical solution supply means (not shown) such as a separately provided pump, and opening and closing the opening and closing valve 8 appropriately, A predetermined amount of the chemical solution 6 is discharged (dropped) from a discharge nozzle 3 provided at an end of the pipe 7 onto an object 4 such as a substrate placed below the discharge nozzle 3.

[0007]

In the above-mentioned chemical liquid discharging means (hereinafter simply referred to as discharging means 22), foreign substances may be generated in the chemical liquid 6 in the pipe 7. For example, drug solution 6
Is a photosensitive resin (photoresist), foreign matters are generated in the chemical solution 6 due to solidification of a part of the photosensitive resin. If the chemical solution 6 mixed with foreign matter is discharged and applied to the object 4 to be applied, there arises a problem that a desired final product cannot be obtained.

[0008] Therefore, in order to remove foreign matter in the chemical solution 6,
As shown in FIG. 4, a foreign matter removing filter 10 may be inserted in the middle of the pipe 7. In FIG. 4, the foreign matter removing filter 10 is inserted between the opening and closing valve 8 and the discharge nozzle 3. However, the foreign matter removing filter 10 may be inserted before the opening and closing valve 8. However, even if the foreign matter removal filter 10 is inserted in the middle of the pipe 7 and foreign matter in the chemical solution 6 can be removed, if the distance between the foreign matter removal filter 10 and the discharge nozzle 3 is long, the foreign matter removal filter 10 will not be removed. It can be said that there is a possibility that a foreign substance is newly generated in the chemical solution 6 after the foreign substance is removed by the method. For this reason, it can be said that it is desirable to insert the foreign matter removing filter 10 before the discharge nozzle 3 as much as possible. However, when the foreign matter removing filter 10 is inserted between the opening / closing valve 8 and the discharge nozzle 3, the following problem may occur depending on the type of the chemical solution 6 (for example, photoresist) and the supply pressure.

That is, the discharge of the chemical 6 from the discharge nozzle 3 is started with the open / close valve 8 opened, and then the open / close valve 8 is closed when a predetermined amount of the chemical 6 is discharged from the discharge nozzle 3. Also, immediately after closing, the supplied chemical solution 6 remains in the filter 10 for removing foreign substances in a state of having a pressure. For this reason, even if the opening / closing valve 8 is closed, the chemical solution 6 remaining in the pipe near the discharge nozzle 3 or the foreign matter removal filter 10 for a while due to the residual pressure of the chemical solution 6 in the foreign matter removal filter 10. Is extruded, and the extruded chemical solution 6 is discharged onto the object 4 to be coated, that is, a so-called liquid dripping occurs.

Conventionally, in order to prevent liquid dripping from the discharge nozzle 3, as shown in FIG. 5, a sack valve 9 is provided immediately after the open / close valve 8 (when the valve is closed, a chemical liquid is increased by means such as increasing the internal volume of the valve). (A valve that draws the gas into the valve). However, even if liquid dripping can be prevented by the operation of the sack valve 9, if the foreign matter removing filter 10 is provided near the discharge nozzle 3,
When the sack valve 9 draws in the chemical, the chemical flows backward through the foreign matter removing filter 10. As a result, when the chemical solution is a photosensitive resin (photoresist), there is a problem that a gel-like foreign matter is generated on the secondary side (exit side) of the foreign matter removing filter 10 requiring cleaning.

Further, as the discharging operation is performed, the foreign matter removing filter 10 gradually becomes clogged by the foreign matter in the chemical solution. As the clogging of the foreign matter removing filter 10 progresses, the negative pressure generated in the foreign matter removing filter 10 when the sac valve 9 is closed (when the chemical solution is drawn in) gradually increases.

When the foreign matter removing filter 10 is increasingly clogged and the negative pressure generated in the foreign matter removing filter 10 increases to a certain extent, the chemical solution may foam and generate foam. In this case, the next time the liquid is ejected, the foam extruded from the foreign matter removing filter 10 becomes bubbles and mixes into the chemical solution 6, and the chemical solution 6 containing the bubbles is ejected to the object 4. Occurs. In addition, when the inside of the pipe 7 has a negative pressure due to the suction of the chemical solution 6 by the suck valve 9 or the like, air bubbles may be generated by suction of air from the outlet of the discharge nozzle. Are mixed.

Further, when foam is generated in the foreign matter removing filter 10, the inside of the foreign matter removing filter 10 is in a mixed phase of a liquid phase and foam, and the foam has a so-called balloon effect (pressure is reduced). When applied, the foam shrinks and the volume decreases, and when the pressure is lost or the pressure becomes negative, the foam expands and the volume increases). For this reason, when the foam in the foreign matter removing filter 10 expands and its volume increases, the chemical solution is pushed out, and liquid dripping occurs.

After the chemical solution 6 is discharged onto the object 4 and a film is formed on the object 4 with the discharged chemical solution 6 by, for example, spin coating, a predetermined amount of the chemical solution 6 is dripped or the like. If the film is not ejected onto the object 4, the film thickness formed on the object 4 will be different from the desired film thickness. For this reason, a desired manufacturing result cannot be obtained in the manufacturing process performed after the application, and the product becomes defective, and even if bubbles are mixed in the discharged chemical solution, the product becomes defective.

For example, the chemical solution 6 is a photoresist in which a color pigment is dispersed, and after the photoresist is discharged onto the object 4 (eg, a glass substrate), the photoresist film is formed on the glass substrate by rotating the glass substrate. Spin coating,
Thereafter, a pattern filter is formed on a glass substrate by performing pattern exposure, development, burning treatment, and the like. In this case, if the above-mentioned liquid dripping occurs and a predetermined amount of photoresist cannot be dropped on the glass substrate, the film thickness of the color filter formed on the glass substrate becomes different from the desired film thickness, and the spectral characteristics and light This is a color filter having a transmittance different from a desired value. Also, if bubbles are mixed in the discharged photoresist,
The bubbles become defects such as pinholes on the color filter.

In the production of a shadow mask,
If the thickness of the etching-resistant layer becomes thicker than desired due to liquid dripping, the removal of the etching-resistant layer performed after etching becomes insufficient, and a part of the etching-resistant layer remains in the product, and rust and the like may occur later. It is the cause. further,
Even when a pinhole is formed in the etching resistant layer due to bubbles of the chemical solution, unnecessary etching is performed and the product becomes defective.

The present invention has been made in view of the above-described problems, and has as its object to provide at least a discharge nozzle, a pipe for supplying a chemical solution to the discharge nozzle, and an opening / closing valve provided in the middle of the pipe. A coating device capable of discharging a predetermined amount of a chemical solution containing no foreign matter and air bubbles, wherein the coating device includes at least a discharging unit and discharges a chemical solution onto an object to be coated by the chemical solution discharging unit. It is intended to provide.

[0018]

Means for Solving the Problems In order to achieve the above object in the present invention, first, in claim 1, at least a discharge nozzle, a pipe for supplying a chemical solution to the discharge nozzle, and A chemical solution application device comprising at least a chemical solution discharging means comprising an opening / closing valve provided, wherein the chemical solution discharging means discharges a chemical solution onto an object to be applied from the chemical solution discharging means, wherein the chemical solution discharging means is provided immediately after the opening / closing valve. A valve, a filter for removing foreign matter disposed between the sac valve and the discharge nozzle and in a pipe near the discharge nozzle, and connecting the pipe on the sac valve side and the pipe on the discharge nozzle side to form the filter for removing foreign matter. A bypass pipe for bypassing the filter, between a branch point on the sack valve side of the bypass pipe and a foreign matter removing filter, and two points on the bypass pipe. And a switching valve provided at a location.

According to a second aspect of the present invention, there is provided the chemical liquid applying apparatus according to the first aspect, wherein the foreign matter removing filter is provided with an open / close valve for venting air.

Further, in the third aspect, an open / close valve for venting air is provided between the open / close valve provided on the bypass pipe and a branch point of the bypass pipe on the dropping nozzle side. A chemical liquid application device according to 1 or 2.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of one embodiment of a coating apparatus 1 according to the present invention, in particular, two parts of a chemical solution discharging means. Here, as shown in FIG. 1, the pipe-shaped pipe 7 having the discharge nozzle 3 connected to the end thereof is conventionally brought to a predetermined pressure by a chemical solution supply means (not shown) such as a separately provided supply pump. A chemical solution 6 (for example, a photoresist solution in which a coloring pigment is dispersed) is supplied. Also, in the pipe 7,
An opening / closing valve 8a and a suck valve 9 are provided. When discharging (dropping) the chemical solution 6 onto the coating object 4 such as a glass substrate or a thin metal plate placed below the discharge nozzle 3, the opening / closing valve 8 a is opened, and conversely, when the discharge of the chemical solution 6 is stopped. And the on-off valve 8a is closed. The opening and closing of the sack valve 9 is synchronized with the opening and closing of the opening and closing valve 8a. That is, when the open / close valve 8a is open, the suck valve 9 is also opened, and when the open / close valve 8a is closed, the suck valve 9 is also closed. Further, as is well known, a chemical solution is drawn into the sack valve 9 by means such as increasing the volume in the sack valve 9 at the same time as the sack valve 9 is closed.

Here, as a feature of the coating apparatus 1 of the present invention, first, as shown in FIG. 1, a filter for removing foreign matter is provided between the suck valve 9 and the discharge nozzle 3 and on the pipe 7 near the discharge nozzle 3. 10 is installed (inserted). In addition, as shown in FIG.
A bypass pipe 11 is provided to bypass the air. Furthermore, the branch point 12a to the bypass pipe 11 on the side of the suck valve 9
An opening / closing valve 8b and an opening / closing valve 8c are provided between the opening and closing valve 8b and the foreign matter removing filter 10, and on the bypass pipe 11, respectively. In conjunction with the opening and closing of the sack valve 9, the opening and closing are performed as follows.

That is, when the chemical solution 6 is discharged from the discharge nozzle 3, the opening and closing valve 8a and the suck valve 9 are opened, the opening and closing valve 8b is opened, and the opening and closing valve 8c is closed. Foreign matter is removed from the chemical solution 6 via the opening / closing valve 8a, the sack valve 9 and the opening / closing valve 8b by the foreign matter removing filter 10 inserted near the discharge nozzle 3. Here, since the distance between the foreign matter removing filter 10 and the discharge nozzle 3 is short, no foreign matter is newly generated in the chemical solution 6 from which the foreign matter has been removed by the foreign matter removing filter 10.
The chemical solution 6 is discharged from the discharge nozzle 3 in a clean state.
Needless to say, when the chemical solution 6 is discharged, the opening / closing valve 8c
Is opened, a part of the chemical solution 6 is
Since the chemical liquid 6 is discharged without passing through the bypass pipe 11, the opening / closing valve 8c is closed when the chemical solution 6 is discharged.

Next, when the discharge of the chemical solution 6 from the discharge nozzle 3 is stopped, the open / close valve 8a and the suck valve 9 are closed, the open / close valve 8b is closed, and the open / close valve 8c is opened. Conventionally, as described above (problems to be solved by the invention), even if the on-off valve 8a is closed to stop the discharge of the chemical solution from the discharge nozzle 3, the pressure remains in the foreign matter removing filter 10. This causes liquid dripping from the discharge nozzle 3 due to this pressure. However, in the present invention, the bypass pipe 11 is provided, and the pressure in the foreign matter removing filter 10 is changed to the branch point 12b,
It is absorbed by the sack valve 9 via the bypass pipe 11 and the opened and closed valve 8c. That is, the chemical solution 6 is drawn into the sac valve 9 by means such as increasing the volume in the sack valve 9 at the same time as the sack valve 9 is closed. The pressure in 10 is also absorbed. Thus, even when the foreign matter removing filter 10 is inserted in the vicinity of the discharge nozzle 3, the liquid dripping from the discharge nozzle 3 when the discharge of the chemical solution 6 is stopped can be prevented.

When the discharge of the chemical solution 6 from the discharge nozzle 3 is stopped, the opening and closing valve 8b is closed and the opening and closing valve 8c is opened.
There is no negative pressure inside. Therefore, the foreign matter removing filter 10 described in the above (Problems to be Solved by the Invention)
It is possible to prevent the generation of foam (bubbles) generated when the inside becomes a negative pressure, and to prevent the bubbles from being mixed into the chemical solution.

Next, when the discharge of the chemical solution 6 from the discharge nozzle 3 is restarted, the opening / closing valve 8a and the suck valve 9
Is opened, the opening and closing valve 8b is opened, and the opening and closing valve 8c is closed. When the opening and closing valve 8c is closed, it can be said that the chemical in the opening and closing valve 8c is pushed out. That is, as shown in FIG. 2, when the on-off valve 8c is closed, the valve 13c projects and shuts off the chemical solution path.
Will be extruded. For this reason,
When the chemical solution pushed out when the opening / closing valve 8c is closed reaches the discharge nozzle 3, liquid dripping occurs from the discharge nozzle 3.

However, in the present invention, the open / close valve 8b
As shown in FIG. 2, the on-off valve 8c is closed and the on-off valve 8b is opened at the same time. That is, when the opening / closing valve 8b is opened, the valve 13b that has been blocking the chemical solution path is stored, and the volume of the stored valve 13b is reduced in the chemical solution path. When the volume is reduced, the chemical solution pushed out when the open / close valve 8c is closed is sucked, and the pushed chemical solution does not reach the discharge nozzle 3. That is, the provision of the open / close valve 8b can prevent liquid dripping from the discharge nozzle 3 immediately after restarting the discharge of the chemical solution 6.

Next, when the liquid supply is restarted after replacing the foreign substance removing filter 10 with a new one, the foreign substance removing filter 10 becomes clogged with air or becomes trapped in the air. The invention according to claim 2 has been made to prevent this, although air bubbles may be mixed in. As shown in FIG. 3, a foreign matter removing filter 10 is provided with a filter for removing air (air). An opening / closing valve 8d is provided. By appropriately opening the open / close valve 8d, the air (air) in the foreign matter removing filter 10 can be removed, and it is possible to prevent bubbles from being mixed into the discharged chemical solution 6. Note that the air (air) bleeding is to push out air by the pressure of the chemical solution when the pressure is applied to the foreign matter removing filter 10 when the chemical solution 6 is discharged. The opening / closing valve 8d is closed when the air (air) bleeding from the inside is completed.

Further, in the coating apparatus 1 of the present invention, since the bypass pipe 11 is provided near the discharge nozzle 3 via the branch point 12b, there is a possibility that air may enter the bypass pipe 11. When air (air) enters the bypass pipe 11, the air (air) in the bypass pipe 11 is sucked out when the chemical solution 6 is discharged from the discharge nozzle 3, and may enter the chemical solution 6 as bubbles. There is. The invention according to claim 3 has been made to prevent this, and an air opening / closing valve is provided between an opening / closing valve 8c provided in the bypass pipe 11 and a branch point 12b of the bypass pipe 11 on the side of the drip nozzle 3.
8e.

By opening the opening / closing valve 8e appropriately, the air (air) in the bypass pipe 11 can be evacuated, and it is possible to prevent bubbles from being mixed in the dripped chemical solution 6. In addition,
In the case of removing air (air) from the bypass pipe 11, the chemical 6
When pressure is applied to the bypass pipe 11 during discharge of
The air is pushed out by the pressure of the chemical solution 6, and, of course, the opening / closing valve 8e is closed when the air (air) in the bypass pipe 11 is completely removed.

Each of the above-mentioned open / close valves (including the sack valve) is a valve that is manually opened / closed, and each open / close valve may be manually opened / closed. However, in order to adjust the opening / closing timing of each opening / closing valve and always keep the amount of the chemical solution discharged from the discharging nozzle constant, an opening / closing nozzle (for example, an air operated valve) that can be opened and closed mechanically is used. It is desirable. An open / close valve is an air operated valve and a separately provided control device (not shown)
To send high-pressure air to each open / close valve in a timely manner,
By controlling the opening and closing of each of the interlocking open / close valves described above, it is possible to always discharge a desired amount of the chemical liquid onto the object to be coated without dripping, and to discharge the chemical liquid that does not include bubbles and foreign matter. Becomes

Next, in the coating apparatus 1 of the present embodiment, substrate rotating means (not shown) for rotating the object 4 to be coated.
After the chemical solution 6 is ejected onto the object 4 by the above-described ejection means, a process such as rotating the object 4 is performed, and a coating of a predetermined thickness is performed with the ejected chemical solution 6. A film is formed on the object 4 to be coated.

As described above, an example of the embodiment of the present invention has been described. For example, the length of the bypass pipe, the branch point of the bypass pipe, and the specific positions of the respective on-off valves and the foreign matter removing filter are described as follows. The pressure may be appropriately set depending on conditions such as the pressure applied to the chemical solution and the viscosity of the chemical solution. That is, the embodiments of the present invention are not limited to the above description and drawings, and various modifications may be made based on the spirit of the present invention.

[0035]

In the coating apparatus according to the present invention, it is possible to discharge a desired amount of a chemical liquid onto the object to be coated without dripping, and to discharge a chemical liquid containing no foreign matter and no bubbles. Thereby, a point that has been a problem in the conventional coating apparatus, that is, a desired amount of a chemical solution is not discharged by liquid dripping, and a film thickness of a film formed on an object to be coated does not become a desired film thickness, or In addition, the present invention has solved the problem that, for example, pinholes are formed in a coating film formed on an object to be coated by mixing foreign matter and air bubbles into a chemical solution.

Further, as another effect of the present invention, the frequency of replacing the foreign matter removing filter 10 can be reduced, and the effect that the equipment cost is reduced also occurs. That is, in the conventional discharging means, as described above (the problem to be solved by the invention), when the discharge of the chemical solution 6 is stopped, the filter for removing foreign substances clogged to a certain extent is Is negative pressure, and foam is generated in the foreign matter removing filter. for that reason,
Frequent replacement of foreign matter removal filters was required.
However, in the present invention, since the opening and closing valve 8b is closed and the opening and closing valve 8c is opened, the inside of the foreign matter removing filter 10 does not become negative pressure when the discharge of the chemical solution 6 is stopped. For this reason, even if the foreign matter removing filter 10 is clogged to some extent, it is possible to prevent the generation of bubbles (bubbles) due to the negative pressure in the filter. That is, in the present invention, it is possible to use a filter for removing foreign substances which has been conventionally clogged, and the filter for removing foreign substances can be used.
10 can reduce the frequency of replacement.

[0037]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a main part of an embodiment of a coating apparatus of the present invention.

FIG. 2 is a partially enlarged explanatory view showing a main part of one embodiment of the coating apparatus of the present invention.

FIG. 3 is an explanatory view showing a main part of another embodiment of the coating apparatus of the present invention.

FIG. 4 is an explanatory view showing a main part of an example of a conventional coating apparatus.

FIG. 5 is an explanatory view showing a main part of another example of a conventional coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 21 Coating device 2, 22 Discharge means 3 Nozzle 4 Coating object 5 Mounting table 6 Chemical solution 7 Piping 8 Valve 9 Suck valve 10 Filter 11 Bypass piping 12 Branch point 13 Valve

Continuation of the front page (72) Inventor Toshiyuki Koizuki 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. (72) Inventor Takashi Ueno 1-15-1 Taito, Taito-ku, Tokyo Letterpress printing Inside the corporation

Claims (3)

[Claims] At least a chemical solution discharge means comprising a discharge nozzle, a pipe for supplying a chemical solution to the discharge nozzle, and an opening / closing valve provided in the middle of the pipe, is provided. In the chemical liquid applicator which discharges a chemical liquid, the chemical liquid discharging means includes: a sack valve provided immediately after an opening / closing valve; and a foreign substance disposed between the sack valve and the discharge nozzle and in a pipe near the discharge nozzle. A filter for removing, connecting a pipe on a sack valve side and a pipe on a discharge nozzle side, and bypassing the foreign matter removing filter; and a bypass pipe between the sack valve side of the bypass pipe and the foreign matter removing filter. And an opening / closing valve provided at two locations on the bypass pipe. 2. The chemical liquid applicator according to claim 1, wherein the foreign matter removing filter is provided with an opening / closing valve for venting air. 3. The chemical solution according to claim 1, wherein an opening / closing valve for venting air is provided between the opening / closing valve provided on the bypass pipe and a branch point of the bypass pipe on the discharge nozzle side. Coating device.