JP2000334355A - Piston pump, coater and coating method, and plasma display, manufacturing apparatus of display part and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replace a coating liquid or the like in a short period of time in a coating liquid feed line by installing respective fluid-passages in a cylinder storing a fluid inside and in a piston feeding the fluid to the inside or the outside of the cylinder by reciprocal motion, of a piston pump. SOLUTION: In a die coat method which is used for forming a coating film C on the surface of a material A to be coated such as a glass substrate or the like while a coating liquid 114 delivered out of contact with the surface, a piston pump 120 is used as a feeding means of the coating liquid 114 to a die 30. In order to feed the coating liquid 114 in a tank 112 to the die 30, a piston 128 is travelled to the lower side by a definite quantity and a cylinder 124 is filled in with the coating liquid 114 through a fluid-passage 132, after a taken-in valve 126 is opened and a delivery valve 122 is closed. Then, the piston 128 is travelled to the upper side by a definite quantity and the coating liquid 114 in the cylinder 124 is fed to a manifold 62 of the die 30 through an outlet 136, after the taken-in valve 126 is closed and the delivery valve 122 is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a piston pump,
The present invention relates to a coating apparatus, a coating method, and a method for manufacturing a plasma display or a plasma display member. INDUSTRIAL APPLICABILITY The present invention can be used, for example, in the field of manufacturing plasma displays, color filters for color liquid crystal displays, optical filters, printed boards, integrated circuits, semiconductors, and the like. More specifically, the present invention is to form a coating film while discharging a coating liquid in a non-contact manner on the surface of a member to be coated such as a glass substrate.

[0002]

2. Description of the Related Art In recent years, displays have been gradually diversified in their system, but one of the things that are currently attracting attention is a plasma display which is larger and thinner and lighter than a conventional cathode ray tube. In this method, a partition having grooves extending in one direction in a stripe pattern at a constant pitch is formed on a glass substrate, and R, G, and B phosphors are filled into the grooves of the partition, and an arbitrary portion emits light by ultraviolet rays. Let
This is to project a predetermined color pattern. Usually, the one with the partition is called the back plate, and the one with the electrode that determines the part to be emitted is called the front plate.

An important method of forming a partition pattern on the back plate is to apply a partition paste uniformly, dry the mixture to form a film having a uniform thickness, and form a stripe-shaped groove having a predetermined pitch by sandblasting. The mainstream is engraving and firing by post-processing such as a photolithography method. The thickness of the coating of the partition walls is 100 to 200 μm even after firing.
As a means to uniformly apply thousands to tens of thousands of cps of partition wall paste on a glass substrate to this film thickness, a screen printing method that repeats application and drying of the coating film repeatedly until a predetermined thickness is achieved Is generally used. However, in this method, the number of repetitions of coating and drying is 10 to 20 times. Therefore, in order to reduce the cost and improve the quality, introduction of a roll method or a die coating method, which can complete the coating in one time, has been actively pursued in recent years. Has begun.

[0004] Among them, the die coating method using a die can perform coating only once, and (1) since the die as an applicator is not in contact with the glass substrate, screen unevenness remains on the coating surface. Quality can be improved (2)
Since there are no consumables such as a screen, there are merits such as eliminating the trouble and cost of replacement.

[0005] As means for supplying the coating liquid to the die, there are a constant volume pump such as a gear pump, a diaphragm pump, and a piston pump also called a syringe pump, and air pressure feeding for feeding the coating liquid at a constant air pressure. However, a constant displacement pump that stably obtains a constant coating thickness irrespective of the viscosity of the coating liquid and has little time fluctuation is often used.

[0006] In the case of applying to a sheet-like material such as a glass substrate with a die, an intermittent operation is required for a constant-volume pump, so that the intermittent operation can be easily controlled.
86, a diaphragm pump described in
A piston pump described in Japanese Patent Application Publication No. 60020 or the like is often used.

FIG. 4 shows a conventional piston pump 30.
FIG. 2 is a schematic cross-sectional view showing a configuration of a zero. Referring to FIG. 4, the piston pump 300 includes a three-way valve 320 and a pump unit 301. The pump unit 301 includes a cylinder 302 for storing the coating liquid therein, a piston 304 for discharging or sucking the coating liquid into and out of the cylinder 302, and a cylinder 3.
A seal member 306 such as an O-ring for preventing the application liquid in the fluid 02 from flowing out from the piston 304. On the other hand, the three-way valve 320 has a fluid passage 326 in the main body 322,
This is connected to the passage 328 in the ball 324, so that either the valve inlet BI or the valve outlet BO can be connected to the inlet / outlet PIO of the pump. The selection of the connection port is performed by the rotation of the ball 324. The selection of the connection port and the operation of the piston 304 allow the application liquid to be sucked into the cylinder 302 from the valve inlet BI and the coating liquid is discharged from the cylinder 302 to the valve outlet BO. Or you can.

[0008]

The intermittent constant displacement pump including the piston pump shown in FIG. 4 has the following problems. (1) Since the application liquid is suctioned and stored once in the pump and then discharged, the application liquid in the application liquid supply line consisting of a die and a piping line is replaced, or the cleaning liquid is passed through for cleaning. Or when it takes time. (2) There are many portions that easily stay in the pump, and it takes time to replace the coating liquid with a new coating liquid or a cleaning liquid for cleaning. In particular, since the suction and discharge of the coating liquid are performed at the same passage, the replacement operation takes a considerable amount of time. (3) When applying to a sheet-like material, it is required to reduce a so-called defective portion where the film thickness does not reach a predetermined constant value at the application start / end portions. One effective means of reducing the defective portion of the coating start portion is to start coating by discharging the coating liquid that has reached the discharge speed corresponding to the substrate running at a constant speed from the die, and for this reason, The shorter the time required for the discharge speed of the coating liquid to reach the predetermined value from zero,
That is, the higher the responsiveness, the shorter the defective portion at the application start portion. In the intermittent constant displacement pump, 1) due to the characteristics of the motor used, it takes a certain time to reach a predetermined discharge speed, and the response is low. 2) The piping from the pump to the die is usually a flexible tube made of a resin such as Teflon or the like because a path is easily formed. The flexible tube is elastically contracted by the internal pressure, and when the application liquid is started to be discharged from the pump, it expands to the pressure at the time of discharge, so that the tube functions as a buffer for the coating liquid,
Even if the pump itself reaches the predetermined mechanical speed, the coating liquid sent from the pump is consumed for the expansion of the tube, and as a result, the coating liquid discharged from the die does not reach the predetermined discharging speed, further reducing responsiveness. Let me do it.

On the other hand, in the air pressure feeding, since the moving speed of the air is high, the discharge speed of the coating liquid from the die can immediately reach a predetermined value from zero, so that the defective portion of the coating start portion can be reduced. As described above, due to the influence of the viscosity and the change in the state of the inside of the die, the discharge amount in the steady portion changes with time, so that it cannot be used stably for a long time.

That is, according to the conventional coating liquid supply method, it is impossible to reduce the defective portion at the coating start portion and to reduce the film thickness unevenness at the steady portion over a long period of time. (4) In the case of an intermittent constant displacement pump in which the fluid path is switched by a three-way valve as in the piston pump of FIG. 4, 1) In the middle of the three-way valve switching operation, the fluid path is both on the inflow side and the discharge side. Since the valve is closed, if the switching operation of the three-way valve is performed during the operation of the pump, mechanical damage occurs due to an increase in the internal pressure. 2) When the supply of the coating liquid is stopped by stopping the operation of the pump,
It takes a certain time to stop from the predetermined discharge speed,
It is not possible to reduce the defective film thickness portion at the end of coating.

The present invention has been made on the basis of the above-mentioned circumstances, and has as its object to provide an intermittent constant displacement pump such as a piston pump and a die coater using the same. (2) Replace the coating liquid and the cleaning liquid in a short time because there is no stagnant part in the intermittent type constant volume pump. Even if an intermittent constant displacement pump is used, the response of the coating liquid discharge from the die is increased to minimize the defective film thickness at the start of coating and to reduce the film thickness unevenness in the steady portion over a long period of time. (4) Even if an intermittent constant displacement pump is used, the response of stopping the coating liquid from the die is increased, and the defective film thickness portion at the end of coating can be minimized, thereby improving productivity and product productivity. To improve the quality It is an object of the present invention to provide a piston pump, a coating apparatus, a coating method, and a plasma display or display member manufacturing apparatus and method.

[0012]

The object of the present invention is achieved by the following means. (1) A piston pump having a cylinder for storing a fluid therein and a piston for supplying the fluid into and out of the cylinder by reciprocating motion, wherein a fluid passage is provided in each of the cylinder and the piston. (2) a coating liquid supply device for supplying a coating liquid, a coating device having a discharge port extending in one direction for discharging the coating liquid supplied from the coating liquid supply device to a member to be coated, the coating device and the coating target A moving means for relatively moving at least one of the members to form a coating film on the member to be coated, wherein the coating liquid supply device is a piston pump according to (1). A coating device characterized by comprising: (3) a coating liquid supply device for supplying a coating liquid, a coating device having a discharge port extending in one direction for discharging the coating liquid supplied from the coating liquid supply device to a member to be coated, the coating device and the coating device A moving unit for relatively moving at least one of the members to form a coating film on the member to be coated, wherein the coating liquid supply device supplies a constant volume of the coating liquid. A coating apparatus comprising: a capacity supply unit; and a constant-pressure supply unit that supplies a coating solution at a constant pressure. (4) The coating apparatus according to (3), further comprising selection control means for selecting either the constant-volume supply means and the constant-pressure supply means to operate independently or in combination. The coating device according to (4), wherein (6) The constant volume supply means is a constant volume pump, and the constant pressure supply means is an air pressurizing device for pressurizing the application liquid in the supply tank by air. 3. The coating device according to claim 1. (7) An apparatus for manufacturing a plasma display or a member for a display, comprising the coating apparatus according to any one of (2) to (6). (8) A coating method in which at least one of the coating device and the member to be coated is relatively moved while a coating solution is discharged from a discharge port extending in one direction of the coating device to form a coating film on the member to be coated. The method according to claim 1, wherein the supply of the coating liquid to the coating device is performed using both a constant volume supply and a constant pressure supply. (9) The coating method according to (8), wherein the supply of the coating liquid to the coating device is performed by either constant volume supply or constant pressure supply during coating. (10) The coating according to (8) or (9), wherein both the constant volume supply and the constant pressure supply are performed at the time of starting or finishing the application of the application liquid to the member to be applied of the application device. Method. (11) The coating method according to any one of (8) to (10), wherein the constant volume supply is performed by a constant volume pump and the constant pressure supply is performed by air pressurization. (12) The coating method according to (11), wherein the constant displacement pump is the piston pump according to (1). (13) A method for manufacturing a plasma display or a member for a display, comprising manufacturing a plasma display or a member for a display using the coating method according to any one of (8) to (12).

According to the piston pumps (1) and (2) and the coating apparatus using the same, despite the fact that the pump is an intermittent constant displacement pump, there is no stagnation in the pump and the coating liquid and the cleaning liquid are removed. The replacement can be performed in a short time, and the replacement of the coating liquid and the cleaning liquid in the die and the piping line can be performed in a short time.

Further, (3) to (6), (8) to (12)
According to the coating apparatus and the coating method of the above, since the constant volume supply and the constant pressure supply of the coating liquid are used together, the response of the coating liquid discharge from the die is improved, and the film thickness defective portion at the coating start portion is reduced. While making it very small, it is possible to keep the film thickness unevenness in the steady part small over a long period of time.

Furthermore, according to the apparatus and method for manufacturing a plasma display or a member for a display according to (7) and (13), a plasma display or a member for a display can be obtained by using the above-described excellent piston pump and coating apparatus and method. Therefore, a high quality plasma display or display member with a very small thickness defect in the coating start part and a very small thickness unevenness in the steady part is produced with high productivity. It is possible to do.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view of a coating apparatus which is a die coater according to the present invention, and FIG.
FIG. 2 is a schematic configuration diagram around a table 6, a die 30, and a supply device.

Referring to FIG. 1, there is shown a coating apparatus by a die coating method applied to manufacture a partition of a plasma display according to the present invention, that is, a so-called die coater 1. The die coater includes a base 2, on which a pair of guide groove rails 4 is provided. A table 6 as a holder for the substrate A (member to be coated) is arranged on the guide groove rails 4, and the upper surface of the table 6 is configured as an adsorption surface 10 having an adsorption hole to which the substrate A can be fixed by vacuum suction. Have been. The table 6 freely reciprocates in the horizontal direction on the guide groove rail 4 via the pair of slide legs 8.

Between the pair of guide groove rails 4, a casing 12 having feed screw mechanisms 14, 16, 18 as moving means shown in FIG.
2 extends in the horizontal direction along the guide groove rail 4.
As shown in FIG. 2, the feed screw mechanisms 14, 16, and 18 have a feed screw 14 formed of a ball screw, and the feed screw 14 is connected to a nut-shaped connector 16 fixed to the lower surface of the table 6. Screwed into
It extends through this connector 16. Both ends of the feed screw 14 are rotatably supported by bearings (not shown), and an AC servo motor 18 is connected to one end thereof.

Referring again to FIG. 1, an inverted L-shaped die support 20 is disposed substantially at the center of the upper surface of the base 2. The tip of the die column 20 is positioned above the reciprocating path of the table 6, and a holder 22 is attached thereto via a lifting mechanism (not shown). The holder 22 holds a die 30 as an applicator. As is clear from FIG. 1, the die 30 extends directly above the table 6 in a direction orthogonal to the reciprocating direction of the table 6, that is, horizontally in the longitudinal direction of the die 30, and both ends thereof are supported by the holder 22. I have. Further, since the lifting mechanism (not shown) can move up and down freely using the AC servomotor as a driving source, the die 30 connected thereto can also be freely moved up and down to an arbitrary position. it can. The holder 22 has an adjustment mechanism (not shown) for adjusting the positions of both ends of the die 30 in the up-down direction, and can set the gap between the discharge port surface 74 of the die 30 and the table in parallel. Further, a coating liquid supply unit 100 is fluidly connected to the die 30 via a supply hose 102.

As shown schematically in FIG. 2, the die 30 holds the long block-shaped rear lip 60 and front lip 66 together by a plurality of connecting bolts (not shown) in the reciprocating direction of the table 6. It is constituted by being integrally connected. The lowermost surface of the rear lip 60 and the front lip 66 is a discharge port surface 74 that holds the coating film C,
The clearance between the discharge port surface 74 and the clearance of the substrate A is set to an optimum value from the viewpoint of applicability.

In the die 30, a rear lip 60,
A slit 64 serving as a flow path of a coating liquid for forming the coating film C is formed between the slit 64 and the front lip 66.
The slit 64 serves as a discharge port 72 which is an outlet of the coating liquid on the lower surface of the die 30. The gap between the slits 64 is secured by a shim (not shown) sandwiched between the rear lip 60 and the parallel portion of the front lip 66, and can be set to an arbitrary size. The distribution of the discharge amount in the longitudinal direction of the die 30 (the direction perpendicular to the paper surface of FIG. 2) is determined by the distribution of the lip gap in the longitudinal direction of the die 30. That is, when the lip gap is wide, the discharge amount increases, and when the lip gap is narrow, the discharge amount decreases. Further, a manifold 62 is formed on the upstream side of the slit 64 and communicates therewith and extends horizontally in the longitudinal direction of the die 30 (substrate width direction). Further, the manifold 62 is connected to a coating liquid supply unit 100 as a coating liquid supply device via an internal passage of the die 30. The coating liquid supply unit 100 includes a supply hose 10.
2. Filter 104, piston pump 120 as a constant volume pump as a constant volume supply means, suction hose 11
The coating liquid 114 in the tank 112 can be supplied to the die 30. The coating liquid supply unit 100 is disposed on a gantry 116 as can be seen from FIG. The tank 112 is a closed vessel and is a constant pressure air as a constant pressure supply means, or N2.
It is preferably pressurized with an inert gas such as ₂ . The pressure is preferably 0.01 to 1 MPa, more preferably 0.1 to 0.5 MPa.

The piston pump 120 in the coating liquid supply unit 100 is a valve unit including a discharge valve 122 connected to the supply hose 102, a suction valve 126 connected to the suction hose 110, and an outer cylinder. Cylinder 12
4. A ring-shaped seal member 130 such as an O-ring that comes into contact with the inner surface of the cylinder 124, and a pump section including a piston 128 having a fluid passage 132 therein and having the seal member 130 mounted thereon. . The cylinder 124 and the discharge valve 122 are connected to a frame 138 (see FIG. 1).
The suction valve 126 is fixed to a piston 128 via a bracket (not shown). And piston 12
Reference numeral 8 is further connected to a drive mechanism (not shown). This drive mechanism has a linear guide,
An AC servomotor and a ball screw are used for driving, and the connected piston 128 can freely reciprocate up and down at a predetermined speed.

In order to supply the coating liquid 114 in the tank 112 to the die 30 by using the piston pump 120, first, the suction valve 126 is opened while the discharge valve 122 is closed, and then the piston 128 is moved downward. After a certain amount of movement, the coating liquid 114 in the tank 112 is filled into the cylinder 124 through the inflow port 134 and the fluid passage 132. Subsequently, the suction valve 126 is closed, the discharge valve 122 is opened, and then the piston 128 is moved upward by a predetermined amount at a predetermined speed, so that the coating liquid in the cylinder 124 is discharged through the outlet 136 to the manifold 62 of the die 30. Can be supplied to By this series of operations, the coating liquid is transferred from the inlet 134 at the end of the piston 128 to the outlet 136 at the end of the cylinder 124.
Flows in a constant volume only in one direction. The fact that the coating liquid flows only in one direction means that there is no stagnant portion, and when replacing the current coating liquid with another, for example, when replacing the coating liquid with another type or cleaning liquid, Replacement and cleaning operations can be completed quickly.

The piston pump 120 of the present invention can be supplied to the die 30 by applying a constant pressure to the coating liquid in addition to the usage as a constant-volume pump for discharging a constant-volume coating liquid as described above. That is, a constant pressure is applied to the tank 112, the piston 128 is stopped without moving,
When the suction valve 126 and the discharge valve 122 are opened, the coating liquid 11
4 can be supplied to the die 30 at a constant pressure. In this state, if either the suction valve 126 or the discharge valve 122 is closed, the supply of the application liquid can be stopped. Piston pump 120
When a constant volume of a large volume of liquid is supplied to the coating liquid supply line such as the die 30 and the piping, it takes time for intermittent operation, and it takes time to replace the coating liquid and to perform cleaning. If the piston pump 120 is switched to supply a constant pressure in this manner, the liquid can be sent to the coating liquid supply line continuously at a constant pressure and without a stagnation portion. It will be possible.

Further, the piston pump 12 of the present invention
In the case of 0, the above-described constant volume supply operation and the supply of the coating liquid at a constant pressure can be performed simultaneously. That is, first, the tank 11
2, the piston 128 is stopped, the suction valve 126 is opened, and the discharge valve 122 is closed. Next, the piston 128 is started and moved upward to return the application liquid to the tank 112. When the rising speed of the piston 128 reaches a certain speed, the discharge valve 122 is opened. At this time, since both the suction valve 126 and the discharge valve 122 are open, the constant volume supply operation and the supply of the application liquid at a constant pressure are realized. When the suction valve 126 is closed after a certain time while the upward movement of the piston 128 is continued, the tank 1
The supply pressure from 12 is cut off, and the supply is switched to a constant volume supply. Switching from the combination of the constant volume supply operation and the constant pressure supply to the constant volume supply can be easily performed by this valve operation. Such a combination of constant pressure and constant volume application liquid supply
This is effective when the discharge start is short and a constant amount of the coating liquid is desired to be supplied regardless of a change in the viscosity of the coating liquid. That is, since the discharge start time can be much shorter in the case of the constant pressure supply than in the case of the constant volume supply, at the start of the discharge, both the constant pressure supply and the constant volume supply operation are performed, and the discharge amount becomes constant in a short time. , The constant volume supply, which is not related to the change in viscosity, only allows the advantages of both supply methods to be utilized.

The effect of shortening the discharge start time by the constant pressure supply is that when the supply hose 102 expands by applying pressure and the amount of liquid stored in the hose is large, for example, a flexible tube made of Teflon or the like is used. The larger the inner diameter and the longer the length, the more effective. That is, in such a case, when a constant volume of the application liquid is supplied, the supply hose 102 expands until the discharge pressure is reached,
Here, the coating liquid supplied from the piston pump 120 at a constant volume is accumulated, so that the amount of the coating liquid discharged from the discharge port of the die 30 does not reach the predetermined amount. Since this state continues until the expansion of the supply hose 102 is completed, a time response delay of the discharge occurs. In such a case, when the constant pressure supply is used, the application liquid is supplied at a high flow velocity in the pipe according to the difference between the pressure applied to the tank 112 and the pressure of the supply hose, so that the supply hose expands for a very short time. And the delay in the ejection response time can be reduced to almost zero.

Further, in the piston pump 120 of the present invention, the discharge of the coating liquid from the die 30 can be completed in a short time not only at the start of the discharge of the coating liquid but also at the end of the discharge, thereby improving the responsiveness. That is, the tank 112 is at atmospheric pressure, the suction valve 126 is closed, the discharge valve 122 is opened, and the piston 128 is raised at a constant speed.
26 is opened, the discharge 122 valve is closed, and the supply of the coating liquid to the die 30 is stopped. The deceleration operation for stopping the piston 128 is performed after the suction valve 126 is opened. By this valve switching operation, the supply of the coating liquid to the die 30 can be stopped not by stopping the piston 128 but by closing the discharge 122 valve, so that the application from the die 30 is not affected by the deceleration time of the piston 128. Discharge of the liquid can be stopped instantaneously. Further, after the opening operation of the suction valve 126 or simultaneously with the closing of the discharge valve 122, the discharge valve 1 is closed.
After the closing operation of 22, the application liquid sent out by the piston 128 is returned to the tank 112, so that mechanical damage to the cylinder 124 and the like due to an increase in the internal pressure can be avoided.

Referring again to FIG. 2, the piston pump 1
The operating conditions such as the opening / closing timing of the suction valve 126 and the discharge valve 122, the operation timing of the piston 128, the application liquid discharge amount, and the discharge speed in 20 are determined by the computer 54 to which each device is electrically connected. It is controlled independently for each device. Further, in order to control the operation of the piston pump 120 in conjunction with the table 6 or the like, the computer 54 informs the feed screw 14 of the table 6 that the A
A C servo motor 18 and an AC servo motor for raising and lowering the die 30 are electrically connected, and a signal indicating an operation state of the AC servo motor 18 and the like, and a position sensor 58 for detecting a moving position of the table 6 are provided. A signal, a signal from a sensor (not shown) for detecting the operation state of the die 30, and the like are input.

Instead of using the position sensor 58, an encoder may be incorporated in the AC servomotor 18 and the computer 54 may detect the moving position of the table 6 based on a pulse signal output from the encoder. is there.

Next, a coating method using the die coater 1 which is a coating apparatus according to the present invention will be described.

First, when the origin of each operating section in the coating apparatus is returned, the table 6 and the die 30 move to the standby position (origin position). At this time, the coating liquid tank 112
The coating liquid 114 is already filled up to the die 30,
The so-called air bleeding operation of discharging the coating liquid with the die facing upward to discharge the residual air inside the die has already been completed.

Next, the inclination of the die 30 is adjusted so that the discharge port surface 74 of the die 30 is parallel to the suction surface 10 with reference to the suction surface 10 of the table 6. At this time, associating the discharge port surface 74 with the suction surface 10 of the table 6 as a reference point and the vertical coordinate axis (Z-axis) value of the elevating mechanism, that is, so-called origin determination of the discharge port surface 74 is simultaneously executed and completed. With this, if the vertical coordinate axis value of the lifting mechanism is controlled,
The discharge port surface 74 can be moved from the suction surface 90 to an arbitrary height position. When these operations are completed, the table 6 and the die 30 are returned to the origin.

After the preparation operation is completed, lift pins (not shown) are lifted on the surface of the table 6 and the substrate A is placed on the upper portion of the table from a transfer machine (not shown). The substrate A is placed and sucked.

Next, the table 6 is moved at a predetermined speed, and stopped when the coating start portion of the substrate A comes directly below the discharge port of the die 30. In this stopped state, the thickness of the substrate A is measured by a thickness sensor (not shown), and a value to be lowered by the die 30 is calculated from the thickness and the clearance given as a condition in advance. The die 30 descends.

On the other hand, the piston pump 120 has moved the piston 128 down to a predetermined position while the suction valve 126 is open and the discharge valve 122 is closed, and the cylinder 124
Is already filled with the coating liquid 114 and is in a standby state. Then, the suction valve 126 is closed and the discharge valve 122 is opened.
The application liquid 114 is sent to the die 30 by raising the pressure 28.
After the operation of feeding the coating liquid by the piston pump 120 is started, a timer in the computer 54 is started, and after a predetermined time, a start signal is output from the computer to the AC servomotor of the table 6, and the table 6 starts moving at the coating speed. Then, the application is started.

When the coating end portion of the substrate A comes to a position immediately below the discharge port of the die 30, a signal is output from the computer 54 to stop the piston pump 120 and raise the die 30, so that the coating liquid is completely removed from the substrate. Quick.

On the other hand, the table 6 continues to move, and stops when the substrate A reaches the end position where the substrate A is transferred by the unloader, releases the suction of the substrate A, raises the lift pins, and lifts the substrate A. At this time, the lower surface of the substrate A is held by an unloader (not shown), and the substrate A is transported to the next drying step. When the delivery to the unloader is completed, Table 6
Lowers the lift pin and returns to the home position.

During this time, the piston pump 120 performs a suction operation to fill the tank 112 with a new coating liquid 114. Next, the same operation is repeated until the next substrate A comes.

In the above coating operation, the responsiveness of the start and stop of the discharge at the start and end of the coating is improved to greatly reduce the defective film thickness portion where the film thickness does not reach a certain value. Implement the method.

The operation of preparing the piston pump 120 and the die 30 and the operation of transferring the substrate A to the table 6 and adsorbing the substrate A are exactly the same as those described above. The coating thickness of the substrate A is measured in advance, and the die 30 is lowered to a position where the clearance has a given value accordingly.
On the other hand, in the coating liquid supply unit 100, the piston pump 12
The cylinder 124 of No. 0 is filled with the application liquid, a predetermined pressure is applied to the tank 112, the suction valve 126 is opened, the discharge valve 122 is closed, and the piston 128 is stopped.

When the lowering of the die 30 is completed, the table 6
At the same time, the piston 128 also starts to rise and reaches a predetermined constant speed, and the coating liquid 114 is stored in the tank 11.
Return to 2. Next, when the application start portion of the substrate A is located immediately below the discharge port of the die 30, the discharge valve 122 is opened and the die 3 is opened.
The application liquid is discharged from 0 to start the application, and after a certain time, the suction valve 126 is closed, and a constant amount of the application liquid is continuously discharged from the die 30 to continue the application. While both the table 6 and the piston 128 are operating at a predetermined constant speed, the additional pressure of the tank 112 is released and returned to normal pressure. Then, when the application end portion of the substrate A is located immediately below the discharge port of the die 30, the suction valve 126 is opened, the discharge valve 122 is closed, and the discharge of the coating liquid from the die 30 is stopped. The piston 128 is decelerated and stopped after the suction valve 126 is opened. Then, the die 30 is raised at the same timing as when the discharge of the application liquid is stopped, and the application liquid is completely drained from the substrate. Thereafter, the substrate is transferred to the drying step, and the table 6, the piston pump 12
In both cases, the home return operation is performed to prepare for the next substrate.

Although an apparatus for cleaning the discharge port surface of the die is not shown in the above description of the present invention, a means for cleaning the discharge port surface such as wiping or cleaning with a cleaning liquid is added to the die coater. You may. Thus, the application can be started with the discharge port surface of the die always being cleaned, so that the film thickness profile at the application start portion can be easily controlled to a desired one.

The coating liquid to which the present invention can be applied has a viscosity of 1 cps to 100,000 cps, preferably 10 cps.
It is from ps to 50,000 cps, and Newtonian is preferable from the viewpoint of applicability, but it can also be applied to a coating liquid having thixotropic properties. As the substrate A, besides glass, a metal plate such as aluminum,
A ceramic plate, a silicon wafer, or the like may be used. Further, as a coating condition to be used, a clearance (for required one) is 40 to 500 μm, more preferably 8 to 500 μm.
0 to 300 μm, coating speed 0.1 m / min to 10 m /
Min, more preferably 0.5 m / min to 6 m / min, the die lip gap is 50 to 1000 μm, more preferably 100 m / min.
６００600 μm, the coating thickness is 5 to 400 μm, more preferably 20 to 250 μm.

In the above embodiment, the piston pump 1
Although an example of the combination of the constant volume supply using the pressure pump 20 and the constant volume supply operation and the constant pressure supply by the pressure feed has been described, the coating may be performed only by the constant pressure supply by the pressure feed using the piston pump according to the present invention. The air pressure for constant pressure supply is 0.0
1-1 MPa, more preferably 0.05-0.5 MPa
It is.

As the suction valve 126 and the discharge valve 122, besides a ball valve, any valve such as a diaphragm valve, a tube valve, a plug valve, a needle valve, etc. may be used as long as the function as a two-way valve is satisfied. You may. As these materials, in addition to metals such as stainless steel, ceramics, resins such as Teflon and polypropylene, and materials partially coated with ceramics or Teflon may be used.

Further, the cylinder 124 and the piston 128
As a material for the above, in addition to metals such as stainless steel, ceramics, resins such as Teflon, glass and the like are preferable. The inner diameter of the cylinder 124 and the moving stroke amount of the piston 128 may be determined from the required storage amount determined from the application amount, but the inner diameter of the cylinder 124 is 5 to 100 mm, preferably 10 to 50 mm.
mm, the moving stroke amount of the piston 128 is 20 to 500.
mm, preferably 40 to 300 mm. Silicon rubber, Kalrez, Viton,
Other than a rubber O-ring such as EPDM, a resin such as Teflon, a mechanical seal capable of self-sealing by internal pressure, a V-ring, or the like may be used.

The object of the display member manufacturing apparatus according to the present invention is preferably a color filter used for a liquid crystal display in addition to a back plate and a front plate of a plasma display.

[0048]

EXAMPLES The effects of the present invention will be specifically described below with reference to examples. Example 1 A photosensitive silver paste was screen-printed to a thickness of 5 μm on the entire surface of a soda glass substrate having a width of 440 mm × 470 mm × a thickness of 2.8 mm, and then exposed using a photomask, followed by development and baking. Through, pitch 220μm
Thus, 1920 silver electrodes in a stripe shape were formed. A glass paste composed of glass and a binder was screen-printed on the electrode, and then fired to form a dielectric layer. Next, a stainless steel die having a discharge width of 430 mm and a lip gap (shim thickness) of 500 μm was attached to the die coater of FIG. On the other hand, the piston pump 12 of the coating liquid supply unit 100
At 0, a stainless steel cylinder having an inner diameter of 40 mm was used for the cylinder 124, and a stainless air-operated two-way ball valve was used for each of the suction valve 126 and the discharge valve 122. The coating liquid supply line from the stainless steel tank 112 to the die 30 was filled with a photosensitive glass paste having a viscosity of 20,000 cps and comprising 60% of glass powder and a photosensitive organic component. Close the discharge valve 122, open the suction valve 126,
A pressure of 0.2 MPa was applied to the tank 112, and the die was lowered so that the clearance between the die and the dielectric layer became 350 μm. At this time, the piston 128
Was moved upward at a speed of 0.9 mm / sec (corresponding to 1.15 cc / sec), and then the substrate was moved at a speed of 0.5 m / min.
The discharge valve 122 is opened when a position 6 mm from the top of the substrate is just below the die discharge port, and one second later, the suction valve 126 is opened.
Was closed, and the application of the photosensitive glass paste was started from a position 10 mm from the top of the substrate. Tank 1 during application
The pressure applied to the suction valve 1 is returned to the atmospheric pressure, and when the substrate reaches a position 456 mm from the top of the die just below the die, the suction valve 1 is turned on.
26 was opened, the discharge valve 122 was closed to stop the discharge, the die was raised, and the glass paste was completely cut off from the substrate. The piston 128 decelerated and stopped after the opening operation of the suction valve 126. Thus, coating was completed at a position 460 mm from the top of the substrate. Next, the substrate after completion of the application was taken out by a transfer machine, put into a drying furnace using a radiation heater, and dried at 100 ° C. for 20 minutes. When the coating thickness distribution after drying was measured over the coating direction,
As shown by the solid line in FIG. 3, the steady part is the target of 140 μm.
It was confirmed that each of the portions which did not fall within this film thickness range of ± 3 μm and the coating start and end portions was 10 mm or less. The dashed line in FIG. 3 is obtained by applying the same thickness and speed using the conventional piston pump shown in FIG. 4, and it is clear that the defective film thickness portions at the start and end of coating have been considerably improved. became.

The substrate was then exposed using a photomask designed to form partitions between adjacent electrodes, and developed and fired to form partitions. The shape of the partition walls was 220 μm in pitch, 30 μm in line width, and 130 μm in height, and the number of partition walls in each region was 1921. Thereafter, R, G, and B phosphor pastes are sequentially applied by screen printing, and dried at 80 ° C. for 15 minutes.
Baking was performed at 0 ° C. for 15 minutes to produce a back plate of the plasma display. The film thickness unevenness of the obtained plasma display back plate was within 3 μm, and the surface quality was satisfactory. Next, the rear plate and the front plate of the plasma display were combined and sealed, and a mixed gas of Xe 5% and Ne 95% was sealed therein, and a driving circuit was connected to obtain a plasma display.

[0050]

Since the piston pump according to the present invention has a structure capable of discharging the coating liquid only in one direction, there is no stagnation portion, and the replacement and cleaning of the coating liquid can be reliably performed in a short time.

Further, since it is possible to use both the constant volume supply and the constant pressure supply, it is possible to enhance the response of the application liquid to start discharging and to eliminate the change in the discharge amount due to the change in viscosity. By the coating apparatus and the coating method using the pump, it is possible to minimize the film thickness defective portion at the coating start portion and to extremely reduce the film thickness unevenness at the steady portion for a long time.

In addition, despite being a constant capacity intermittent pump,
Since the liquid can be continuously supplied at a constant pressure, replacement and cleaning of the coating liquid in a coating liquid supply line such as a die and a pipe can be performed in a shorter time than at the time of constant volume intermittent supply.

Further, since the discharge of the coating liquid from the die can be instantaneously stopped by switching the valve, the defective film thickness portion at the end of coating can be minimized.

With the above-described piston pump, coating apparatus, and plasma display or display member manufacturing apparatus and manufacturing method using the coating method having excellent effects, high quality plasma displays and display members can be manufactured with high productivity. It can be produced industrially.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a die coater according to an embodiment of the present invention.

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

FIG. 3 is a comparison diagram of the coating thickness of one embodiment in which the coating film thickness profiles of the present invention and a conventional coating method are compared.

FIG. 4 is a sectional view schematically showing a conventional piston pump.

[Explanation of symbols]

 1: die coater 2: base 6: table 10: suction surface 14: feed screw (ball screw) 18: AC servo motor 30: die 54: computer 100: coating liquid supply unit 102: supply hose 112: tank 114: coating liquid 120 : Piston pump 122: Discharge valve 124: Cylinder 126: Suction valve 128: Piston 130: Sealing material (O-ring) 300: Piston pump (conventional product) A: Substrate (member to be coated) C: Coating film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H070 AA07 BB07 CC31 CC33 DD08 DD26 DD62 4D075 AC04 AC94 AC95 CA48 DA06 DB13 DC24 EA45 4F041 AA05 CA02 CA16 CA25

Claims (13)

[Claims] 1. A piston pump having a cylinder for storing a fluid therein and a piston for supplying the fluid into and out of the cylinder by reciprocating motion, wherein the cylinder and the piston are each provided with a fluid passage. . A coating liquid supply device for supplying the coating liquid; a coating device having a discharge port extending in one direction for discharging the coating liquid supplied from the coating liquid supply device to a member to be coated; And a moving unit for relatively moving at least one of the members to be coated to form a coating film on the member to be coated. A coating device comprising a piston pump. A coating liquid supply device for supplying the coating liquid; a coating device having a discharge port extending in one direction for discharging the coating liquid supplied from the coating liquid supply device to a member to be coated; A moving means for relatively moving at least one of the members to be coated to form a coating film on the member to be coated, wherein the coating liquid supply device supplies a constant volume of the coating liquid. And a constant pressure supply unit for supplying a coating solution at a constant pressure. 4. The coating apparatus according to claim 3, further comprising a selection control means for selecting one of the constant-volume supply means and the constant-pressure supply means to operate independently or to use both. 5. The coating apparatus according to claim 4, wherein the coating selection control means is an open / close valve. 6. The constant volume supply means is a constant volume pump, and the constant pressure supply means is an air pressurizing device for pressurizing the application liquid in the supply tank by air. 3. The coating device according to claim 1. 7. An apparatus for manufacturing a plasma display or a member for a display, comprising the coating apparatus according to any one of claims 2 to 6. 8. A coating film is formed on the member to be coated by moving at least one of the coating device and the member to be coated while discharging the coating liquid from a discharge port extending in one direction of the coating device. In the coating method, the coating liquid is supplied to the coating device by using both a constant volume supply and a constant pressure supply. 9. The coating method according to claim 8, wherein the supply of the coating liquid to the coating device is performed during the coating by either a constant volume supply or a constant pressure supply. 10. The coating according to claim 8, wherein the constant-volume supply and the constant-pressure supply are performed at the time of starting or finishing the application of the application liquid to the member to be applied of the application device. Method. 11. The constant volume supply is performed by a constant volume pump.
The coating method according to any one of claims 8 to 10, wherein the constant pressure supply is performed by air pressurization. 12. The coating method according to claim 11, wherein the constant volume pump is the piston pump according to claim 1. 13. A method for manufacturing a plasma display or a member for a display, comprising manufacturing a plasma display or a member for a display using the coating method according to any one of claims 8 to 12.