JPH06339656A - Liquid applicator - Google Patents

Abstract

PURPOSE:To make the thickness of a film at the beginning of application uniform in a slot type spray for viscous fluid. CONSTITUTION:A sack back valve 120, a valve 122, and a control valve 123 are attached to a liquid supply pipe 121 connected with an opening 105 for injecting liquid to be applied of an application head 55. Sack back valve 128a, 128b, valves 125a, 125b, and control valves 126a, 126b are attached to liquid discharge pipes 127a, 127b connected with openings 106a, 106b for discharging liquid to be applied of the application head 55. At the end of application, when the time T2 has passed since the valve 122 on the liquid supply side being closed, the valves 125a, 125b together with the sack back valves 120, 128a, 128b are closed to reduce the liquid pressure in the application head 55 in order to prevent the sagging of the liquid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluid application device.
Specifically, the present invention relates to a slot type fluid application device for applying a fluid with a uniform film thickness to the surface of an object to be coated, in order to make the film thickness of the end portion of the fluid coating film uniform. Regarding technology.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal display (LCD), a semiconductor optical element, a semiconductor element, a semiconductor integrated circuit, a printed wiring board, etc., various coating liquids such as a photoresist, an insulating material, a solder resist, etc. For example, it is necessary to apply it to the surface of a glass substrate, a semiconductor wafer, etc.) to form a very thin coating film of about several microns.
For example, in the manufacturing process of a liquid crystal display, it is necessary to coat the surface of a glass substrate with a uniform photoresist having a dry thickness of about 1 to 3 microns.

In such a case, it is necessary to form a coating film having an extremely uniform film thickness, and moreover, it is necessary to control the film thickness with high precision. Therefore, conventionally, a spin coater is generally used as a coating device. It is used.

The spin coating method using a spin coater is
While the object to be coated is rotated at a constant number of revolutions, the coating solution is dropped on the base layer, and the coating solution is thinly spread by centrifugal force,
In this method, a coating film having a film thickness determined by the viscosity of the coating liquid, the number of revolutions, etc. is formed on the surface of the coating object.

However, according to such a spin coating method, the coating liquid cannot be selectively applied to only a part of the object to be coated, and only the entire surface of the object to be coated can be coated. Further, only a few percent of the coating liquid dropped onto the coating target is coated on the surface of the coating target, and the remaining 90% or more of the excess coating liquid is discharged from the coating target. Moreover, since the discharged coating liquid comes into contact with air, it cannot be collected and reused, and there is a problem that the coating liquid is wasted. Further, a cleaning process for the discharged excess coating liquid has been required. Further, when applied by the spin coat method, the coating liquid adheres not only to the surface of the object to be coated but also to the end surface (outer peripheral surface) of the object to be coated. The film peels off, the peeled coating film adheres to the surface of the object to be coated, which may cause troubles in the subsequent steps,
This has been a cause of lowering the product yield. Further, in order to avoid the decrease in the yield, it is necessary to clean the end surface and the back surface of the object to be coated, and an additional step for that is required.

As a method for solving the drawbacks of the spin coating method, the applicant of the present invention pays attention to a slot type fluid coating device (slot type mucus spray coating device) and is proceeding with its development and improvement. FIG. 18 is a schematic view showing the structure of a slot type fluid application device 200 developed by the applicant of the present invention. 201 is a coating head,
A first hollow-shaped fluid reservoir 202 is provided on the inner wall surface.
By inserting the shim 205 between the split head 203 and the second split head 204 having a flat inner wall surface, the notch-shaped recess 206 of the shim 205 allows the slot 207 to be formed between the first and second split heads 203 and 204. And the first and second divided heads 203 and 204 are fastened together by bolts (not shown). Further, a liquid injection port 208 communicating with the fluid reservoir 202 is opened on the upper surface of the coating head 201. 209 is the coating liquid 2
The liquid level in the tank 209 is a tank storing 10 and is pressurized by air pressure. The liquid injection port 208 of the coating head 201 and the tank 209 are connected via a liquid supply tube 212 having an opening / closing valve 211. Then, when the opening / closing valve 211 is opened and the coating liquid 210 is injected into the fluid reservoir 202 from the liquid inlet 208, the coating liquid 21
0 uniformly diffuses over the entire width in the fluid reservoir 202, flows into the slot 207 communicating with the fluid reservoir 202, and is adjusted to have a constant film thickness by the gap of the slot 207. It is applied to the surface of objects.

According to such a slot type fluid coating device, the coating liquid can be supplied only from a coating head to a necessary region on the object to be coated without supplying an excessive coating liquid. The yield can be improved and the coating liquid can be saved. Therefore, it is possible to prevent the coating film attached to the side surface of the application object from peeling off and adhering to the application surface of the application object. Further, it is possible to manufacture a closed type fluid application device that can apply the application liquid to an application target without exposing the application liquid to the outside air. Further, there is an advantage that the application head can be easily cleaned.

[0008]

However, in such a fluid coating device 200, a large liquid supply pressure is applied to the coating head 201 during coating, and there is a pressure loss in the slot 207. Therefore, even if the on-off valve 211 is closed and the application is completed, the application head 20
The pressure in 1 does not fall to the atmospheric pressure, and the coating liquid 210 in the coating head 201 is kept in a state where a residual pressure is applied for the time being. Therefore, even after the on-off valve 211 is closed and the application is completed, the application liquid 210 is pushed out from the slot 207, and as shown in FIG. 18, liquid drops occur in the opening of the slot 207. When the on-off valve 211 is opened as it is and the application to the application object 213 is started again, as shown in FIG. 19, the film thickness of the coating film becomes thicker at the application start end of the application liquid 210 due to liquid dripping, and the film thickness becomes uniform. A coating film having a film thickness could not be obtained.

Even when the application of the coating liquid 210 is finished, if the supply of the fluid to the coating head is stopped at the same time when the application of the coating liquid 210 is finished, the film thickness of the coating film is also obtained at the end of the coating of the coating liquid 210. Was thick, and it was not possible to make the end of the coating film on the coating end side uniform.

Further, at the start of coating, FIG.
As shown in (b), when the coating head 201 is lowered and the lower end of the coating head 201 and the coating object 213 become a predetermined interval (time t0), the opening / closing valve 211 is opened to start coating. Since there is a time lag between the timing of opening the on-off valve 211 and the timing of the outflow of the coating liquid 210, when the coating is started immediately after the liquid dripping is completely wiped, the starting end 214 of the coating film is The opening / closing valve 211 is displaced from the opened position α, and the coating liquid 21 is applied at the coating start end.
At 0, a thin portion and a scrape were generated, so that the starting end 214 of the coating film could not be aligned straight as shown in FIG.

The present invention has been made in view of the above technical background, and an object of the present invention is to determine the film thickness at the end portion of the applied fluid coating film in a slot type fluid application apparatus. To make it uniform.

[0012]

A first fluid applying apparatus according to the present invention comprises a fluid injection port for injecting a fluid and a cavity for diffusing the fluid injected from the fluid injection port in the width direction. And a slot for forming a constant thickness of the fluid in the hollow portion and allowing the fluid to flow out, in a fluid coating device, the inside of the coating head is depressurized at the start or end of coating of the fluid by the coating head. It is characterized by having means.

Further, the second fluid applying apparatus of the present invention comprises a fluid injection port for injecting a fluid, a cavity portion for diffusing the fluid injected from the fluid injection port in the width direction, and the cavity. In a fluid application device in which a slot for allowing the fluid in the part to have a constant thickness and flowing out, is formed in the coating head, excess fluid adhering to the slot opening of the coating head is removed, and the fluid in the slot opening is removed. It is characterized in that a means for smoothing the interface is provided.

Further, the third fluid applying apparatus of the present invention comprises a fluid injection port for injecting a fluid, a cavity for diffusing the fluid injected from the fluid injection port in the width direction, and the cavity. In a fluid application device in which a slot for allowing a fluid in a part to have a constant thickness and flowing out is formed in a coating head, the supply of the fluid to the coating head is started before the application of the fluid is started. Is characterized by.

Further, a fourth fluid applying apparatus of the present invention is a fluid injection port for injecting a fluid, a cavity for diffusing the fluid injected from the fluid injection port in the width direction, and the cavity. In a fluid application device in which a slot for allowing a fluid in a portion to have a constant thickness and flowing out is formed in a coating head, the supply of the fluid to the coating head is stopped before the application of the fluid is completed. It is characterized by having done.

[0016]

In the first fluid application apparatus of the present invention, since the pressure inside the application head can be reduced when the application of the fluid by the application head is started or finished, the residual pressure in the application head is removed. It is possible to make the coating liquid in the slot tend to fall, prevent the coating film from being thickly attached at the start of the application of the fluid, and make the coating film thickness uniform.

In particular, if the pressure is reduced at the end of coating, the residual pressure in the coating head can be removed immediately after the coating is finished, or the coating liquid in the slot can be pulled down. It is possible to prevent dripping of the coating head.

Further, in the second fluid coating apparatus of the present invention, since the excess fluid adhering to the slot opening of the coating head can be removed, the coating film is formed by the excess fluid at the start of coating. The coating start end can be prevented from becoming thick, and the film thickness of the coating film can be made uniform.
Furthermore, since the excess fluid can be removed and the fluid interface can be made substantially uniform in the width direction, the coating start ends of the coating film can be aligned straight and the quality of the coating film can be improved.

Further, in the third fluid applying apparatus of the present invention, the fluid is started to be supplied to the application head shortly before the application of the fluid is started. It is possible to prevent the film thickness of the coating film from becoming thin and to prevent scraping, and it is possible to straighten the coating start end of the coating film.

Further, in the fourth fluid applying apparatus of the present invention, the supply of the fluid to the application head is stopped just before the application of the fluid is finished, so that the fluid is not applied at the end of the application. It is possible to prevent the thickness of the coating film from increasing, and it is possible to align the coating end ends of the coating film in a straight line.

[0021]

1 is a perspective view showing the external appearance of a fluid applying apparatus A according to an embodiment of the present invention. This fluid applying device A is
A cabinet 2 having a door 3 and an apparatus main body 1 are provided. A tank and a controller for accumulating a coating liquid are stored in the cabinet 2, and the apparatus main body 1 is installed on the cabinet 2. The apparatus main body 1 mainly includes a feed mechanism section 21 for horizontally feeding the coating object, a coating mechanism section 51 for coating the coating liquid on the surface of the coating object fed by the feeding mechanism section 21, and a plate thickness of the coating object. And a measuring head 81 for measuring just before coating. Further, on the front surface of the apparatus main body 1, there is provided an operation unit 4 in which a display panel, dials, meters, various switches and the like are concentrated. A cover 5 that can be opened and closed is provided above the device body 1.
It can be covered by.

The feed mechanism section 21 sucks the object 11 to be coated such as a glass substrate and horizontally conveys it at a constant speed, and the structure thereof will be described in detail with reference to the sectional view of FIG. A pair of parallel guide rails 23 are provided on the upper surface of the base 22 and 4 provided on the lower surface of the table 24.
One slider 25 is slidably supported by a guide rail 23, and the table 24 runs smoothly along the guide rail 23. Further, a male screw shaft 26 is arranged in parallel with the guide rail 23 in the center of the base 22, and both ends of the male screw shaft 26 are rotatably supported by the base 22 via angular bearings 27. A female screw tube 28 fixed to the lower surface of 24 and a male screw shaft 26 are screwed together to form a ball screw mechanism. A servo motor 29 is fixed to the end of the base 22.
The output shaft of is connected to the male screw shaft 26 via a joint 30. Therefore, the table 24 can be moved at a constant speed along the guide rail 23 by rotating the male screw shaft 26 at a constant rotation speed by the servo motor 29. In this embodiment, the table 24
Although the servo motor 29 is used as the power for moving the table 24, when a flammable coating liquid is used, the table 24 may be moved by a non-electrical means such as an air mechanism.

The table 24 has a large number of vacuum suction holes 3
The suction plate 32 having the holes 1 is placed on the table body 33, and a vacuum chamber 34 is formed between the suction plate 32 and the table body 33. Then, the air in the vacuum chamber 34 is exhausted to make the inside of the vacuum chamber 34 a vacuum or a negative pressure so that the lower surface of the coating object 11 such as the glass substrate placed on the suction plate 32 is sucked. Thus, the object 11 to be coated can be fed at a constant speed together with the table 24. At this time, the table 24 also has an effect of correcting the warp of the application target 11 by adsorbing the application target 11. Also,
A detachable pin and an alignment pin (not shown) are housed in the table 24. After the inside of the vacuum chamber 34 is opened to normal pressure, the detachable pin is removed from the pin projecting hole 35 of the suction plate 32. By projecting, the lower surface of the coating object 11 is pushed up, and the coating object 11
Can be forcibly peeled from the table 24.

As shown in FIG. 1, the coating mechanism section 51 has a feeding mechanism section 21 so as to straddle the conveyance path of the coating object 11.
Is provided above. FIG. 3 is a diagram showing the coating mechanism 51 in detail from the side. In the coating mechanism section 51, a coating arm 54 is horizontally installed between the upper ends of a pair of lifting rods 53 held by a lifting holder 52 so as to be slidable up and down, and a coating head 55 is provided on the front surface or the back surface of the coating arm 54. Is fixed. The elevating holder 52 is fixed to a shelf portion 56 projecting laterally from the base 22, and the air cylinder 5 is provided directly below the elevating rod 53.
7 is installed, and the upper end surface of the output shaft 58 of the air cylinder 57 faces the lower end surface of the elevating rod 53. Reference numeral 60 is a bellows that covers the lifting rod 53. Therefore, the output shaft 58 of the air cylinder 57 is projected upward, and the lifting rod 53
When the lower end surface of the coating head is pushed up, the coating head 55 rises together with the coating arm 54. When the output shaft 58 of the air cylinder 57 is retracted downward, the coating head 55 moves down together with the output shaft 58 due to its own weight.

Further, a numerical control type linear actuator 6 is provided just below the coating head 55 or the coating arm 54.
1 is installed. This linear actuator 61
Is connected to a motor 63 such as a servo motor or a pulse motor via a joint 62. When the input shaft 64 on the bottom surface is rotated by the motor 63, the stopper rod 65 on the top surface projects upward. Moreover, the linear actuator 61 has a screw mechanism inside, and the stopper rod 65 is moved by a distance proportional to the rotation speed of the input shaft 64.
Protrudes. Then, when the stopper rod 65 of the linear actuator 61 projects, when the output shaft 58 of the air cylinder 57 is retracted and the coating head 55 is lowered, the lower surface of the coating head 55 or the coating arm 54 becomes the upper end of the stopper rod 65. At the moment of contact, the lower end surface of the elevating rod 53 separates from the output shaft 58 of the air cylinder 57, and the coating head 55 is supported and positioned by the linear actuator 61 at that position.

The protrusion distance of the stopper rod 65 of the linear actuator 61 is controlled by the output of the measuring head 81. That is, when the measurement head 81 measures the plate thickness of the coating object 11, the coating head 55 is placed at a position where the gap between the coating head 55 and the coating object 11 is an optimum distance (for example, several tens of microns to several hundreds of microns). Linear actuator 61 for supporting and positioning
The protruding length of the stopper rod 65 is determined.

A measuring head 81 for detecting the plate thickness of the coating object 11 is provided at the center of a measuring arm 82 arranged in parallel with the coating arm 54. In the illustrated example, as the measuring head 81, a non-contact type non-electrical measuring means such as an air micrometer is preferable, but a linear scale may be used, and an electric sensor may be used when a non-flammable coating liquid is used. Alternatively, an optical sensor, a contact sensor, or the like may be used depending on the object 11 to be coated. Reference numeral 91 is a drying prevention device for preventing the coating head 55 from drying.

FIG. 4 shows a sectional view of the coating head 55. The coating head 55 includes two split heads 101,
102 and one shim 103, and FIG. 5 and FIG. 6 are a front view and an exploded perspective view from the inner surface side thereof.
Is shown in. On the inner wall surface of one of the divided heads 101,
As shown in FIG. 5, a fluid reservoir 104 having a hollow shape is provided across the left and right. Fluid reservoir 104
Is horizontally recessed inward from the inner wall surface of the split head 101, and a coating liquid injection port 105 is bored from the upper surface of the split head 101 toward the center of the fluid reservoir 104. A coating liquid discharge port 106 is formed from the upper surface of the divided head 101 toward both ends of the fluid reservoir 104. The other divided head 102 has a protrusion 107 for positioning that protrudes from the upper edge of the inner wall surface. By associating the protrusion 107 with the upper surface of the opposed divided head 101, the application head 55 is assembled. At the same time, the two divided heads 101 and 102 can be aligned with each other. The inner wall surface of the divided head 102 is formed flat except for the through holes 108. In addition, both split heads 10
A tapered portion 109 having a triangular cross-section is projected over the entire width on the inner wall surface side of the lower surface of 1, 102, and a fluororesin 110 such as polytetrafluoroethylene (PTFE) is coated on the entire lower surface. is there. Shim 103
Is a thin metal plate having leg pieces 111 at both ends thereof, and notched recesses 112 are formed between the leg pieces 111.

Therefore, as shown in FIG. 6, the shim 103 is sandwiched between the inner wall surfaces of the two divided heads 101,
102, a split head 102 and a shim 103.
The bolt 114 inserted through the through holes 108 and 113 of the
The application head 55 as shown in FIG. In the coating head 55 thus assembled, the notch-shaped recess 112 of the shim 103 forms the slot 116 for shaping the coating liquid between the inner wall surfaces of the divided heads 101 and 102, and the lower end of the slot 116 is the lower surface of the coating head 55 at the nozzle. Opened as a port 117, the opening of the fluid reservoir 104 faces the upper end of the slot 116 and communicates with the inside of the slot 116.

FIG. 7 is a view showing a coating liquid supply means for supplying the coating liquid 12 to the coating head 55. The coating liquid 12 is stored in an airtight tank 119, and the coating liquid injection port 105 of the coating head 55 and the lower portion inside the tank 119 are connected by a liquid supply pipe 121.
The liquid supply pipe 121 is provided with a suck back valve 120, an opening / closing valve 122, and a flow rate adjusting valve 123.
Alternatively, instead of the flow rate adjusting valve 123, the tank 11
An air regulator 124 may be provided in a pipe line for supplying air to the air conditioner 9. Since the inside of the tank 119 is pressurized by air, the application can be started or stopped by opening / closing the opening / closing valve 122. The supply amount of the coating liquid 12 to the coating head 55 can be adjusted by the flow rate adjusting valve 123 or the air regulator 124. Then, when the opening / closing valve 122 is opened, the coating liquid 12 in the tank 119 is supplied from the coating liquid injection port 105 into the fluid reservoir 104, and the coating liquid 12 fills the fluid reservoir 104 and the fluid reservoir 1
Spread over the entire width within 04. Further, the coating liquid 12 flows out from the fluid reservoir 104 into the slot 116 by the supply pressure, is adjusted to have a uniform film thickness by the slot 116, and flows out from the nozzle opening 117 at the lower end as the coating liquid 12 having a uniform film thickness. A film is formed on the surface of the object 11. Here, there is a constant relationship between the flow rate of the coating liquid 12 and the feeding speed of the coating object 11, and the feeding speed of the coating object 11 is the coating liquid 1
It is larger than the flow rate of 2 (discharge speed). Therefore, the coating liquid 12 having a uniform film thickness ejected from the nozzle port 117 is thinly spread when being applied to the surface of the object 11 to be coated, and is even thinner than the film thickness given by the slot 116. Coating film is formed on the surface of the coating object 11.

Further, the coating liquid discharge port 10 of the coating head 55.
6a and 106b are connected to a recovery tank 129 by liquid discharge pipes 127a and 127b, and the suck back valve 12 is connected to the liquid discharge pipes 127a and 127b.
8a and 128b, opening / closing valves 125a and 125b, and flow rate adjusting valves 126a and 126b are provided. Thus, with the pump 124 operating, the on-off valve 125a,
When 125b is opened, the coating liquid 12 in the fluid reservoir 104 is forcibly discharged from the coating liquid discharge ports 106a and 106b, and the coating liquid 12 discharged from the fluid reservoir 104 is collected in the collecting tank 129. The discharge rate of the coating liquid 12 can be adjusted by the flow rate adjusting valves 126a and 126b. Thereby, the fluid reservoir 1
Since the liquid pressure of the coating liquid 12 at both end portions in 04 becomes low, the distribution of the liquid pressure becomes substantially uniform in combination with the pressure loss in the central portion of the slot 116, and the discharge speed of the coating liquid 12 is adjusted. By doing so, the film thickness of the coating film applied from the coating head 55 to the surface of the coating object 11 can be made uniform in the width direction.

FIGS. 8A and 8B are sectional views showing the structure and operation of the suck back valves 120, 128a, 128b. This suck back valve 120, 128
a and 128b, the piston 4 is placed in the cylinder 41.
2a and 42b are vertically slidably housed, and pistons 42a and 42b are elastically biased upward by a spring 43. On the lower surface of the cylinder 41, the liquid supply pipe 121 or the liquid discharge pipes 127a, 127 is attached.
A body portion 45 connected to b and having a fluid passage 44 for allowing the coating liquid 12 to flow therethrough is integrally attached. A diaphragm valve 46 is disposed in the body portion 45 so as to face the fluid passage 44, an outer peripheral portion of the diaphragm valve 46 is fixed to the body portion 45, and a central portion of the diaphragm valve 46 is connected by a connecting piece 47. It is fixed to the piston 42b. Further, a cover portion 48 is integrally attached to the upper surface of the cylinder 41,
A pressurizing chamber 49 is formed between the upper surface of the piston 42 a and the cover part 48, and an operating port 50 communicating with the pressurizing chamber 49 is opened in the cover part 48.

The suck back valve 12 having such a structure
In Nos. 0, 128a, and 128b, when no air pressure is applied to the pressurizing chamber 49 (hereinafter, referred to as an off state of the suck back valve), as shown in FIG. Since 42b is pushed upward by the spring 43, the central portion of the diaphragm valve 46 is retracted upward by the pistons 42a and 42b, and the volume of the fluid passage 44 is increased. On the other hand, when air is sent from the operation port 50 to apply air pressure to the pressurizing chamber 49 (hereinafter, this state is referred to as an on state of the suck back valve), the pistons 42a and 42b are pushed down by the air, and FIG. As shown in (b), the central portion of the diaphragm valve 46 is projected downward by the pistons 42a and 42b, and the volume of the fluid passage 44 is reduced.

Therefore, if the suck back valves 120, 128a, 128b are used in the ON state during the coating operation, the suck back valve 12 is closed after the on-off valves 122, 125a, 125b are closed and the coating operation is completed.
When 0, 128a, and 128b are turned off, the volume of the fluid passage 44 in the suckback valves 120, 128a, and 128b becomes large.
Are slightly suck back valves 120, 128a, 128b
It is possible to prevent the liquid from being dripped from the nozzle opening 117 of the slot 116 by being drawn into the inside and depressurizing the inside of the coating head 55.

FIGS. 9A, 9B and 9C are explanatory views showing the coating operation by the fluid coating apparatus A. First, when the coating object 11 is supplied onto the table 24 by a loading device (not shown), the coating object 11 is adsorbed to the table 24 and fixed on the upper surface of the table 24. As shown in FIG. 9A, when the coating object 11 fixed to the table 24 is fed below the measuring head 81 by the feeding mechanism section 21, the plate thickness of the coating object 11 by the measuring head 81 ( Alternatively, variation in plate thickness) is measured. When the plate thickness is measured, the lowered position of the coating head 55 is determined, and the protruding length of the stopper rod 65 for stopping the coating head 55 at that position is calculated. Next, the stopper rod 65 of the linear actuator 61
Is projected by a calculated amount, the output shaft 58 of the air cylinder 57 is retracted, the coating head 55 is lowered, and the lowered coating head 55 is stopped by the stopper rod 65. As shown in FIG. The nozzle opening 117 of the head 55 is positioned at a position facing the surface of the coating object 11 with a minute distance therebetween. When the coating start point of the coating object 11 reaches the nozzle opening 117, the double open / close valve 12
2, 125a, 125b are opened to supply the coating liquid 12 into the fluid reservoir 104, and at the same time, a part of the coating liquid 12 in the fluid reservoir 104 is discharged to the coating liquid outlets 106a, 106b.
The coating liquid 12 that has been collected from the nozzle and is adjusted to have a constant film thickness by the slot 116 flows out from the nozzle port 117, and the surface of the coating object 11 that is being sent at a constant speed is coated with the coating liquid 12. At this time, the coating liquid 12 is the coating target 11
Can be applied to the entire surface thereof, but it can also be applied partially to a part of the object 11 to be applied, and not only can it be applied continuously, but it can also be applied intermittently. When the application is completed in this way, as shown in FIG. 9C, the application head 55 is again raised by the air cylinder 57, the application object 11 on the table 24 is separated from the table 24 by the attachment / detachment pin, and the unloading device is used. It is carried out by (not shown).

FIG. 10 shows the opening / closing valve 1 during the above coating operation.
22, 125a, 125b and suck back valve 12
FIG. 10A is a diagram showing the operation timing of 0, 128a, 128b, FIG. 10A shows the elevation of the coating head 55, and FIG. 10B shows the timing of opening / closing the on-off valve 122 on the liquid supply side. 10 (c) is an opening / closing valve 125a on the liquid discharge side,
The timing of opening and closing 125b is shown in FIG. 10 (d). The suck back valves 120, 128a and 128b are turned on,
FIG. 10E shows the timing of turning off, and FIG.
5 shows the change in the liquid pressure within 5. The coating head 55 uses the suck back valve 12 as described above during standby before coating.
The pressure is reduced by the action of 0, 128a, 128b, and it stands by in a state without liquid dripping. When the coating object 11 is sent, the coating head 55 starts to descend at time t1, and when the coating start height h is reached and the distance between the coating object 11 and the coating object 11 becomes a constant interval δ, coating is started from time t3. Although it is started, the open / close valves 122, 12 are started at time t2 earlier than the time t3 when the application is started.
5a and 125b are opened and suck back valve 1
20, 128a and 128b are turned on. On-off valve 12
Even if 2, 125a and 125b are opened, there is a time delay until the hydraulic pressure in the coating head 55 rises as shown in FIG.
By opening 5b earlier by T1 = (t3−t2), the inside of the coating head 55 can be maintained at a sufficient hydraulic pressure at the start of coating, and a coating film having a constant film thickness can be obtained from a desired coating start point. . That is, the coating start end of the coating film can be accurately controlled, the coating start end can be aligned in a straight line, and the coating film thickness can be prevented from becoming thin or faint at the coating start end. It is possible to obtain a coating film of better quality than the starting end, and the yield of the coating film is improved.

This time T1 can be experimentally determined. For example, as shown in FIG. 11, at the moment when the coating head 55 reaches the coating start height h, the opening / closing valves 122, 125a,
125b is opened, and if the distance S between the position α of the slot 116 at that moment and the coating start end of the coating film actually coated on the coating object 11 (distance where the coating is delayed) S is obtained, the conveying speed of the coating object 11 is calculated. Can be determined by T1 = S / V.

When the coating liquid 12 is applied to the coating end position at the time t4, the on-off valve 122 on the liquid supply side is closed and the coating head 55 is raised to finish the coating of the coating liquid 12. At this time, a delay is made from the closing operation of the on-off valve 122, and at the time t5, the on-off valves 125a and 125b on the liquid discharge side.
Close and close all suck back valves 120, 12
Turn off 8a and 128b. On-off valve 125 on the liquid discharge side
When a and 125b are closed at the same time as the liquid supply opening / closing valve 122, it takes time for the liquid pressure in the coating head 55 to decrease to the atmospheric pressure, as shown by the broken line in FIG. 10 (e). When the closing operation of the liquid discharge side opening / closing valves 125a and 125b is delayed by T2 = (t5−t4), the liquid discharge pipe 127 is stopped for T2 after the supply of the coating liquid 12 is stopped.
Since the coating liquid 12 is discharged from the a and 127b, the liquid pressure in the coating head 55 is drastically reduced, and the dripping after the coating is finished is prevented. Further, the on-off valves 125a, 1 on the liquid discharge side
25b is closed and at the same time suck back valve 120,1
When 28a and 128b are turned off, the coating liquid 12 in the coating head 55 is sucked into the suck back valves 120, 128a and 1
Since the coating head 55 is drawn into the coating head 28b, the inside of the coating head 55 is at atmospheric pressure or negative pressure, and the liquid dripping from the coating head 55 is more reliably prevented. Therefore, when the coating operation is started again, it is possible to prevent the coating start end of the applied coating film from becoming thick, and a coating film having a uniform thickness can be obtained.

As a means for reducing the pressure inside the coating head 55 after the coating is finished, in the above embodiment, the suck back valves 120, 128a and 128b are used and the on-off valves 125a and 125b on the liquid discharge side are used for supplying the liquid. On-off valve 12
The method of closing later than 2 was also used, but either one of them may be used.

FIG. 12 is a diagram showing another embodiment of the present invention. This shows another control method in the fluid application device having the application liquid supply means as shown in FIG. In this embodiment, the on-off valve 122 is closed at a time earlier than the time t4 when the application of the coating liquid 12 is finished and the application head 55 is raised, that is, the time t6 (<t4) in FIG. When the application head 55 is raised and the on-off valve 122 is closed at the same time, the application head 55
Due to the coating liquid 12 remaining in the inside,
As shown in FIG. 3 (a), there is a risk that the film thickness will rise and the film thickness will become thicker.
By not supplying the coating liquid 12 to the coating liquid 5, the end portion of the coating film can be thinned as shown in FIG. 13B, and the coating film thickness can be made uniform.

FIG. 14 is a diagram showing still another embodiment of the present invention. In this embodiment, the coating head 55 is set to δ
To the height of the coating liquid, and open the on-off valve 122 to open the coating liquid 12
On-off valve 125a on the discharge side earlier than the start of application of
125b is open. That is, the opening / closing valves 125a and 125b are activated at time t2, which is earlier than the time when application is started at time t3.
Since the inside of the coating head 55 is opened to reduce the pressure, it is possible to prevent the starting end portion of the coating film from rising and becoming thicker, and to make the coating film thickness uniform.

FIGS. 15 and 16 are schematic views showing a part of a fluid applying apparatus B according to still another embodiment of the present invention. FIG. 16 shows a dripping remover 131, in which support pieces 133 are provided on both side surfaces of a box-shaped container 132, and an inclined piece 134 is slanted upward from the rear edge of the upper end of the container 132 toward the rear. And tilt piece 1
A linear liquid adsorbing wire 135 such as a wire or a piano wire is stretched between both supporting pieces 133 above 34.
This dripping remover 131 is attached to the front end of the table 24 as shown in FIG.
Move with 4. In practice, the coating head 55 moves up and down and the table 24 moves horizontally, but in FIG. 15, the table 24 is assumed to be stationary, and the relative movement of the nozzle port 117 of the coating head 55 with respect to the table 24 is indicated by a one-dot chain line. Shown by This will be described with reference to FIG. 15. When the table 24 on which the coating object 11 is placed is sent, the coating head 55 descends toward the liquid adsorption wire 135 of the liquid dripping removal device 131, and the nozzle opening 117 at the lower end.
Stops once at a height that separates a small gap from the liquid adsorbing wire 135. If the nozzle opening 117 and the liquid adsorbing wire 135 pass each other horizontally while maintaining this height, the nozzle opening 11
The coating liquid 12 hanging down from 7 is the wire rod 13 for liquid absorption.
By touching 5, the excess coating liquid 12 is adsorbed by the liquid adsorption wire rod 135 by surface tension, and the liquid adsorption wire rod 1
The coating liquid 12 adsorbed on the 35 is inclined by a weight 13 due to its own weight.
4 and are collected in the container 132 along the inclined pieces 134. On the other hand, in the coating head 55 from which the excess coating liquid 12 has been removed, the interfaces of the coating liquid 12 at the nozzle openings 117 are evenly arranged over the entire length in the width direction. Then, the coating head 55 is lowered again, and is stopped at a position facing the object to be coated 11 at a constant interval and the coating liquid 1 is applied.
Start application of 2. Therefore, since the application of the coating liquid 12 is started in the state where the dripping is removed, the film thickness of the coating film at the application start point can be made uniform.

FIG. 17 is a schematic sectional view showing still another embodiment of the present invention. Instead of the liquid adsorbing wire 135, the slit 13 facing the nozzle opening 117 is shown.
A strip-shaped liquid adsorption member 137 having an opening 6 is used. Also in this embodiment, when the upper surface of the liquid adsorption member 137 is horizontally moved below the nozzle opening 117 with a small gap, the coating liquid 12 dripping from the nozzle opening 117 is absorbed into the slit 136 by the surface tension. Then, it falls into the lower container 132 by its own weight.

The liquid adsorbing wire 135 and the liquid adsorbing member 137 as shown in FIG. 16 and FIG.
The dripping is removed without coming into contact with 7. Of course, the liquid adsorption wire rod 135 and the liquid adsorption member 13
Although it is acceptable to rub the nozzle opening 117 with 7 to remove the liquid dripping, if the nozzle opening 117 is rubbed with the liquid adsorption wire material 135 or the liquid adsorption member 137, dust is generated due to friction. The above-mentioned non-contact method is preferable because it may contaminate the coating film or cause abrasion of the nozzle port 117, the liquid adsorption member 135, and the liquid adsorption member 137. Also, as an adsorption method,
A method of forcibly suctioning vacuum may be used regardless of the surface tension of the coating liquid 12.

[0045]

According to the present invention, the pressure inside the coating head can be reduced at the start of coating or at the end of coating.
The residual pressure in the coating head can be removed and the coating liquid in the slot can be pulled down. As a result, the coating start end of the coating film can be thinned and the coating film thickness can be made uniform. In particular, if the pressure is reduced at the end of coating, it is possible to prevent dripping of the coating head after finishing coating or during suspension of coating.

Alternatively, according to the present invention, the excess fluid adhering to the slot opening of the coating head can be removed. Therefore, by removing the excess fluid immediately before the start of coating, the excess fluid is removed at the start of coating. It is possible to prevent the coating start end of the coating film from becoming thick due to such a fluid, and to make the film thickness of the coating film uniform. Furthermore, since the excess fluid can be removed and the fluid interface can be made substantially uniform, the coating start ends of the coating film can be aligned straight, and the quality of the coating film can be improved.

Alternatively, according to the present invention, since the supply of the fluid to the coating head is started just before the start of the coating of the fluid, the film thickness of the fluid coating film becomes thin at the coating start point. It is possible to prevent the occurrence of abrasion and scrape, and it is possible to align the coating start end of the coating film in a straight line.

Further, according to the present invention, the supply of the fluid to the coating head is stopped just before the completion of the coating of the fluid, so that the film thickness of the fluid coating film becomes thick at the end of coating. Can be prevented, and the end of application of the coating film can be aligned straight.

Therefore, from the beginning to the end of the film thickness of the coating film,
Alternatively, it can be uniformly arranged in the width direction, and a coating film of good quality can be obtained.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a fluid application device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a feeding mechanism portion in the above fluid applying apparatus.

FIG. 3 is a side view showing a coating mechanism section and a measuring head in the above fluid coating apparatus.

FIG. 4 is a cross-sectional view of a coating head in the coating mechanism section of the above.

FIG. 5 is a front view showing each component of the above coating head.

FIG. 6 is an exploded perspective view of the coating head of the above.

FIG. 7 is a schematic diagram showing a configuration for supplying a coating liquid to the coating head of the above.

8A and 8B are cross-sectional views showing the structure and operation of the suck back valve.

9 (a), (b), and (c) are operation explanatory views of the fluid applying apparatus of the above.

FIG. 10 is a diagram showing the relationship among the lifting / lowering operation of the coating head, the opening / closing operation of each on-off valve, the on / off operation of the suck back valve, and the hydraulic pressure in the coating head.

FIG. 11 is a diagram for explaining a method of determining the opening timing of the on-off valve.

FIG. 12 is a diagram showing the relationship among the lifting / lowering operation of the coating head, the opening / closing operation of each on-off valve, the on / off operation of the suck back valve, and the hydraulic pressure in the coating head in another embodiment of the present invention.

13 (a) and 13 (b) are diagrams for explaining the operation of the same.

FIG. 14 is a diagram showing the relationship among the lifting / lowering operation of the coating head, the opening / closing operation of each open / close valve, the on / off operation of the suck back valve, and the hydraulic pressure in the coating head in yet another embodiment of the present invention. .

FIG. 15 is a schematic view showing a part of a fluid application device according to still another embodiment of the present invention.

FIG. 16 is a perspective view showing the dripping removal device of the above.

FIG. 17 is a schematic cross-sectional view showing another liquid adsorption member used in the liquid drip removal device.

FIG. 18 is a schematic configuration diagram showing a conventional fluid application device.

FIG. 19 is a partially cutaway enlarged cross-sectional view showing a state of a coating film when applied by the above fluid applying device.

FIG. 20 is a diagram showing the timing of the lifting operation of the lifting head and the opening operation of the opening / closing valve in the fluid applying apparatus.

21 is a partially cutaway plan view showing the state of the coating film when the coating liquid is applied at the timing of FIG. 20. FIG.

[Explanation of symbols]

 55 coating head 104 fluid reservoir (cavity) 105 coating liquid inlet (fluid inlet) 106 coating liquid outlet (fluid outlet) 116 slot 120 suck back valve 122 open / close valve 125a, 125b open / close valve 128a, 128b suck back valve 131 Liquid Drop Removal Device 135 Liquid Adsorption Wire Rod 137 Liquid Adsorption Member

Claims (4)

[Claims] 1. A fluid injection port for injecting a fluid, a cavity for diffusing the fluid injected from the fluid injection port in the width direction, and a fluid in the cavity part having a constant thickness to flow out. And a slot for forming a slot in the coating head, the fluid coating apparatus comprising means for depressurizing the inside of the coating head when the coating head starts or finishes coating the fluid. 2. A fluid injection port for injecting a fluid, a cavity for diffusing the fluid injected from the fluid injection port in the width direction, and a fluid in the cavity having a constant thickness and flowing out. And a slot for forming a fluid in the coating head, the fluid coating device is provided with means for removing excess fluid adhering to the slot opening of the coating head and making the fluid interface of the slot opening substantially uniform. A fluid application device. 3. A fluid inlet for injecting a fluid, a cavity for diffusing the fluid injected from the fluid inlet in the width direction, and a fluid in the cavity having a constant thickness and flowing out. A fluid application device having a slot for forming in the application head, the supply of the fluid to the application head is started before the application of the fluid is started. 4. A fluid injection port for injecting a fluid, a cavity for diffusing the fluid injected from the fluid injection port in the width direction, and a fluid in the cavity having a constant thickness and flowing out. A fluid application device having a slot for forming the same in the application head, wherein the supply of the fluid to the application head is stopped before the application of the fluid is completed.