JP4366757B2 - Coating apparatus, coating method, and method for manufacturing plasma display or display member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piston pump, a coating apparatus, a coating method, and a method for manufacturing a plasma display or a plasma display member. The present invention can be used in the field of manufacturing, for example, plasma displays, color filters for color liquid crystal displays, optical filters, printed circuit boards, integrated circuits, and semiconductors. In addition, the present invention specifically forms a coating film while discharging the coating liquid in a non-contact manner onto the surface of a member to be coated such as a glass substrate.
[0002]
[Prior art]
In recent years, displays have gradually become diversified in their systems, and one of the current attention is a plasma display that is larger than a conventional cathode ray tube and can be reduced in thickness and weight. This is because a partition having grooves extending in one direction in a striped pattern at a constant pitch is formed on a glass substrate, and further, phosphors of R, G, and B are filled in the grooves of the partition, and an arbitrary portion is emitted by ultraviolet rays. And a predetermined color pattern is projected. Usually, the side with the partition is called the back plate, and the side with the electrode that determines the part to be issued is called the front plate.
[0003]
Here, as an important method of forming a partition pattern on the back plate, a partition paste is uniformly applied, dried to form a uniform film thickness, and then striped grooves with a predetermined pitch are formed by sandblasting or photo The mainstream is engraving and baking by post-processing such as lithography. The thickness of the coating film on the partition walls is as thick as 100 to 200 μm even after firing. As a means for uniformly applying a partition paste of several thousand to several tens of thousands of cps on this film thickness on the glass substrate, it is necessary to obtain a predetermined film thickness. A screen printing method in which coating and drying are repeated many times is generally used. However, with this method, the number of repetitions of coating and drying reaches 10 to 20, so the introduction of roll methods and die coating methods that can complete the coating in one time has been actively pursued with the aim of reducing costs and improving quality. Has begun.
[0004]
Among these, the die coating method using a die can be applied only once, and (1) since the die as an applicator is not in contact with the glass substrate, there is no screen unevenness on the coated surface and the quality is improved. (2) Since there are no consumables such as screens, there are merits such as eliminating the labor and cost of replacement.
[0005]
Examples of means for supplying the coating liquid to the die include a constant capacity pump such as a gear pump, a diaphragm pump, and a piston pump called a syringe pump, and an air pressure feeding that feeds the coating liquid at a constant air pressure. A constant-capacity pump that can stably obtain a constant coating thickness regardless of the viscosity of the liquid and has little time fluctuation is usually used.
[0006]
When applying to a sheet-like object such as a glass substrate with a die, the constant displacement pump requires an intermittent operation, so that the diaphragm described in JP-A-2-223686 is easy to control the intermittent operation. Pumps and piston pumps described in JP-A-9-160020 are often used.
[0007]
Here, FIG. 4 is a schematic sectional view showing a configuration of a conventional piston pump 300. As shown in 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 that stores the coating liquid therein, a piston 304 that discharges or sucks the coating liquid into and out of the cylinder 302, and a sealing material 306 such as an O-ring that prevents the coating liquid in the cylinder 302 from flowing out of the piston 304. Consists of. On the other hand, the three-way valve 320 has a fluid passage 326 in the main body 322, which is connected to the passage 328 in the ball 324 and can connect either the valve inlet BI or the valve outlet BO to the pump inlet / outlet PIO. it can. Selection of the connection port is performed by rotation of the ball 324. By selecting the connection port and the operation of the piston 304, the coating liquid is sucked into the cylinder 302 from the valve inlet BI, or the coating liquid is discharged from the cylinder 302 to the valve outlet BO. You can do it.
[0008]
[Problems to be solved by the invention]
The intermittent constant capacity pump including the piston pump as shown in FIG. 4 has the following problems.
(1) Since the application liquid is once sucked and stored 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 for cleaning. It takes time to do.
(2) Many portions tend to 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 through the same passage port, this replacement operation takes a considerable amount of time.
(3) When applying to a sheet material, it is required to reduce a so-called defective portion where the film thickness does not reach a predetermined constant value at the start and end of application. One effective means of reducing the defective portion of the coating start part 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. The shorter the time for the coating liquid discharge speed to reach a predetermined value from zero, that is, the higher the responsiveness, the shorter the defective portion at the coating start portion. For intermittent constant capacity pumps,
1) Due to the characteristics of the motor used, it takes a certain time to reach a predetermined discharge speed, and the responsiveness is low.
2) The piping from the pump to the die is usually made of a flexible tube made of resin such as Teflon because it is easy to form a path. The flexible tube elastically shrinks due to the internal pressure, and when starting to discharge the coating liquid from the pump, it will expand to the pressure corresponding to the discharge pressure, so the tube functions like a buffer for the coating liquid and the pump itself Even if the pressure reaches a predetermined machine speed, the coating liquid delivered from the pump is consumed for expansion of the tube. As a result, the coating liquid discharged from the die does not reach the predetermined discharge speed, further reducing the responsiveness. End up.
[0009]
On the other hand, in air pressure feeding, since the air moving speed is high, the discharge speed of the coating liquid from the die can be quickly reached from zero to a predetermined value, so that the defective part of the coating start part can be reduced. Since the discharge amount of the steady portion changes with time due to the influence of the viscosity and the state change inside the die, it cannot be used stably for a long time.
[0010]
That is, in the conventional coating liquid supply method, the defective portion at the coating start portion cannot be reduced and the film thickness unevenness at the stationary portion cannot be reduced over a long period of time.
(4) In the intermittent constant capacity pump that switches the fluid path with a three-way valve like the piston pump of FIG.
1) Since the fluid path is closed on both the inflow side and the discharge side during the three-way valve switching operation, mechanical switching due to an increase in internal pressure occurs when the three-way valve switching operation is performed during pump operation. .
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, and the film thickness defective portion at the coating end portion cannot be reduced.
[0011]
This invention has been researched based on the above circumstances, the purpose of which is an intermittent constant capacity pump such as a piston pump, and a die coater using the same,
(1) Replace the coating liquid and cleaning liquid in the coating liquid supply line consisting of a die and a piping line in a short time.
(2) There is no stagnant part in the intermittent constant capacity pump, and the coating solution and cleaning solution are replaced in a short time.
(3) Even when an intermittent constant-capacity pump is used, the responsiveness of discharging the coating liquid from the die is increased, the defective film thickness portion at the coating start portion is minimized, and the uneven thickness of the steady portion is prolonged. Over a small
(4) Even if an intermittent constant capacity pump is used, the response of stopping the coating liquid from the die is increased, and the film thickness defective portion at the coating end portion is minimized.
An object of the present invention is to provide a piston pump, a coating apparatus and a coating method, and a manufacturing apparatus and a manufacturing method for a plasma display or a display member, which can improve productivity and product quality.
[0012]
[Means for Solving the Problems]
The object of the present invention is achieved by the means described below.
(1) Applying liquidOn the applicatorA coating liquid supply device to be supplied; an applicator 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;AboveAnd a moving unit configured to relatively move at least one of the members to be coated to form a coating film on the member to be coated.To the applicatorA constant capacity supply means for supplying a constant capacity;In the supply tank connected to the upstream side of the constant capacity supply meansCoating liquidPressurize at a constant pressure and pass through the fluid passage inside the constant volume supply to the applicator in one direction.Constant pressure supply means for supplying constant pressureWhenConsists ofFurther, a control means for controlling the operation by selecting the single capacity operation or the combination of the constant capacity supply means and the constant pressure supply means is provided.An applicator characterized by that.
(2) The constant-capacity supply means has a cylinder that stores the fluid therein and has an outlet at an end thereof, and a piston that supplies fluid into or out of the cylinder by reciprocation, and the cylinder and the piston The coating apparatus according to (1), wherein each is a piston pump provided with a fluid passage.
(3) (1)Or (2)An apparatus for manufacturing a plasma display or a display member, comprising: the coating apparatus according to claim 1.
(4In the coating method of forming a coating film on the coated member by relatively moving at least one of the coating device and the coated member while discharging the coating liquid from a discharge port extending in one direction of the coating device, Supply of coating liquid to the applicatorAbout the constant capacity supply meansWith constant capacity supplyThe coating liquid in the supply tank connected to the upstream side of the constant volume supply means is pressurized at a constant pressure by the constant pressure supply means and is applied to the applicator in one direction through the fluid passage in the constant volume supply means. SupplyConstant pressure supplyWhenTheAlone orCombined usechooseThe coating method characterized by being performed.
(5) It is characterized in that the constant volume supply and the constant pressure supply are used together at the start of application or at the end of application of the application liquid to the application member of the applicator (4) Application method.
(6)(4) or (5)A method for producing a plasma display or display member, comprising producing the plasma display or display member using the coating method described above.
[0014]
  further(1), (2), (4), (5)According to the coating device and coating method, the constant volume supply and the constant pressure supply of the coating liquid are used in combination.Or selectAs a result, it is possible to increase the responsiveness of the coating liquid discharge from the die and extremely reduce the film thickness defect part at the coating start part, while keeping the film thickness unevenness of the steady part small for a long time. It becomes.
[0015]
  Furthermore (3), (6) Plasma display or display member manufacturing apparatus and method according to the abovePaintedCloth deviceOrSince the method is used to manufacture a plasma display or a display member, a high-quality plasma display in which the defective film thickness portion of the coating start portion is very small and the uneven thickness of the steady portion is kept very small. Alternatively, the display member can be manufactured with high productivity.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described 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. 2 is a schematic configuration diagram around the table 6 and the die 30 and the supply apparatus of FIG.
[0017]
Referring to FIG. 1, there is shown a so-called die coater 1, which is a coating apparatus by a die coating method applied to the manufacture of a partition wall of a plasma display according to the present invention. The die coater includes a base 2 on which a pair of guide groove rails 4 are provided. These guide groove rails 4 are provided with a table 6 as a holder for the substrate A (a member to be coated), and the upper surface of the table 6 is configured as a suction surface 10 having suction holes to which the substrate A can be fixed by vacuum suction. Has been. The table 6 reciprocates freely on the guide groove rail 4 in the horizontal direction via a pair of slide legs 8.
[0018]
A casing 12 containing feed screw mechanisms 14, 16, 18 as moving means shown in FIG. 2 is arranged between the pair of guide groove rails 4. The casing 12 extends horizontally along the guide groove rails 4. It extends. 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 a nut-like connector 16 fixed to the lower surface of the table 6. And extends through this connector 16. Both ends of the feed screw 14 are rotatably supported by a bearing (not shown), and an AC servo motor 18 is connected to one end thereof.
[0019]
Referring again to FIG. 1, an inverted L-shaped die support 20 is disposed at substantially the center of the upper surface of the base 2. The tip of the die support 20 is positioned above the reciprocating path of the table 6, and a holder 22 is attached thereto via an elevating mechanism (not shown). The holder 22 holds a die 30 as an applicator. As is apparent from FIG. 1, the die 30 extends horizontally in the direction perpendicular to the reciprocating direction of the table 6 directly above the table 6, that is, in the longitudinal direction of the die 30, and both ends thereof are supported by the holder 22. Yes. In addition, since the lifting mechanism (not shown) can move up and down freely using an AC servo motor as a drive source, the die 30 connected to the lifting mechanism can be freely moved to any position in the vertical direction. it can. Further, the holder 22 has an adjustment mechanism (not shown) that adjusts the vertical positions of both ends of the die 30 inside, and the interval between the discharge port surface 74 of the die 30 and the table can be set in parallel. Furthermore, a coating liquid supply unit 100 is fluidly connected to the die 30 via a supply hose 102.
[0020]
As shown schematically in FIG. 2, the die 30 has a long block-shaped rear lip 60 and a front lip 66 integrally connected to each other by a plurality of connecting bolts (not shown) in the reciprocating direction of the table 6. It is configured by combining. The lowermost surfaces of the rear lip 60 and the front lip 66 are discharge port surfaces 74 that hold the coating film C, and the clearance from the discharge port surface 74 to the gap of the substrate A is set to an optimum value in view of the coating property.
[0021]
Inside the die 30, a slit 64 is formed between the rear lip 60 and the front lip 66 to serve as a flow path for the coating liquid that forms the coating film C. The slit 64 becomes a discharge port 72 that is an outlet of the coating liquid on the lower surface of the die 30. The gap of the slit 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 (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 apparatus via an internal passage of the die 30. The coating liquid supply unit 100 includes a supply hose 102, a filter 104, a piston pump 120 that is a constant capacity pump as a constant capacity supply means, a suction hose 110, and a tank 112. The coating liquid 114 in the tank 112 is dyed. 30. As can be seen from FIG. 1, the coating liquid supply unit 100 is disposed on a stand 116. The tank 112 is a sealed container, and air of constant pressure as a constant pressure supply means, N₂It is preferable to be pressurized with an inert gas such as. The applied pressure is preferably 0.01 to 1 MPa, more preferably 0.1 to 0.5 MPa.
[0022]
Now, the piston pump 120 in the coating liquid supply unit 100 includes a discharge valve 122 connected to the supply hose 102, a valve portion including a suction valve 126 connected to the suction hose 110, a cylinder 124 serving as an outer cylinder, A ring-shaped sealing material 130 such as an O-ring that comes into contact with the inner surface of the cylinder 124, and a pump unit that includes a piston 128 that has a fluid passage 132 inside and on which the sealing material 130 is mounted. The cylinder 124 and the discharge valve 122 are fixed to the frame 138 (see FIG. 1), and the suction valve 126 is fixed to the piston 128 via a bracket (not shown). The piston 128 is further connected to a drive mechanism (not shown). This drive mechanism uses a linear guide for vertical guidance and an AC servo motor and a ball screw for driving, and can reciprocate freely the piston 128 to be connected at a predetermined speed in the vertical direction.
[0023]
In order to supply the coating liquid 114 in the tank 112 to the die 30 using the piston pump 120, the suction valve 126 is first opened while the discharge valve 122 is closed, and then the piston 128 is moved downward by a certain amount. Then, the coating liquid 114 in the tank 112 is filled into the cylinder 124 through the inlet 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 passes through the outlet 136 and the manifold 62 of the die 30. Can supply. By this series of operations, the coating liquid flows from the inlet 134 at the end of the piston 128 toward the outlet 136 at the end of the cylinder 124 with a constant volume only in one direction. The fact that the coating liquid flows only in one direction means that there is no staying part, and when replacing the current coating liquid with another, for example, when replacing the coating liquid with another type or cleaning liquid, Quick replacement and cleaning can be completed.
[0024]
The piston pump 120 of the present invention can be used as a constant capacity pump that discharges a constant volume of coating liquid as described above, or can be supplied to the die 30 by applying a constant pressure to the coating liquid. That is, by applying a constant pressure to the tank 112, stopping the piston 128 without moving it, and opening the suction valve 126 and the discharge valve 122, the coating liquid 114 can be supplied to the die 30 at a constant pressure. If either the suction valve 126 or the discharge valve 122 is closed in this state, the supply of the coating liquid can be stopped. When a large volume of liquid is supplied to the coating liquid supply line such as the die 30 or the pipe by the piston pump 120, it takes time for the intermittent operation, and it takes time to replace the coating liquid and to wash it. If the piston pump 120 is switched to supply a constant pressure in this way, the liquid can be sent to the coating liquid supply line continuously at a constant pressure and without a stagnant portion. It becomes possible.
[0025]
Furthermore, the piston pump 120 of the present invention can simultaneously perform the above-described constant volume supply operation and supply of the coating liquid at a constant pressure. That is, first, a certain pressure is applied to the tank 112, 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, and the coating liquid is returned to the tank 112. When the ascending speed of the piston 128 reaches a constant 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 coating liquid at a constant pressure are realized. If the suction valve 126 is closed after a predetermined time while the ascending motion of the piston 128 is continued, the supply pressure from the tank 112 is cut off and the supply is switched to the constant capacity supply. Switching from the combined use of the constant capacity supply operation and the constant pressure supply to the constant capacity supply is easily performed by this valve operation. Such combined use of a constant pressure and a constant volume of coating liquid is effective when the discharge start is short and it is desired to supply a constant amount of the coating liquid regardless of changes in the viscosity of the coating liquid. In other words, the constant pressure supply usually allows the discharge start time to be much shorter than the constant volume supply. Therefore, the constant pressure supply and the constant volume supply operation are used together at the start of discharge, and the discharge amount is constant in a short time. If only the constant volume supply not related to the viscosity change is reached, only the advantages of both supply methods can be utilized.
[0026]
The effect of shortening the discharge start time by the constant pressure supply is that the increase in the amount of liquid stored in the hose due to the expansion of the supply hose 102 due to pressure addition is large, for example, using a flexible tube made of Teflon, etc. The larger the length, the more effective. That is, when a constant volume of coating solution is supplied in such a case, the supply hose 102 swells until the discharge pressure is reached, and the coating solution supplied at a constant volume from the piston pump 120 is accumulated therein. The amount of coating liquid discharged from the discharge port does not reach a predetermined amount. Since this state continues until the expansion of the supply hose 102 is completed, a discharge time response delay occurs. In such a case, when constant pressure supply is used, the coating liquid is supplied at a fast pipe flow velocity corresponding to the difference between the pressure applied to the tank 112 and the pressure of the supply hose, so that the expansion of the supply hose takes a very short time. The discharge response time delay can be made almost zero.
[0027]
Furthermore, the piston pump 120 of the present invention can improve the responsiveness by finishing the discharge of the coating liquid from the die 30 not only at the start of the discharge of the coating liquid but also at the end of the discharge. That is, the tank 112 has the atmospheric pressure, the suction valve 126 is closed, the discharge valve 122 is opened and the piston 128 is raised at a constant speed, the suction valve 126 is opened, and the discharge 122 valve is closed. Then, the coating liquid supply 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 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. The liquid discharge can be stopped instantaneously. Further, since the discharge valve 122 is closed after the suction valve 126 is opened or simultaneously, the coating liquid sent out by the piston 128 is returned to the tank 112 after the discharge valve 122 is closed, and the internal pressure rises. There is no need to mechanically damage the cylinder 124 or the like.
[0028]
2 again, the opening / closing timings of the suction valve 126 and the discharge valve 122 in the piston pump 120, and the operation conditions such as the operation timing of the piston 128, the coating liquid discharge amount, and the discharge speed are as follows. Each device is controlled independently by an electrically connected computer 54. Further, in order to control the operation of the piston pump 120 in conjunction with the table 6 and the like, the computer 54 is electrically connected with an AC servo motor 18 for the feed screw 14 on the table 6 side and an AC servo motor for raising and lowering the die 30. A signal indicating the operating state of the AC servomotor 18 and the like, a signal from the position sensor 58 that detects the moving position of the table 6, a signal from a sensor (not shown) that detects the operating state of the die 30, and the like are connected. Is entered.
[0029]
Instead of using the position sensor 58, it is also possible to incorporate an encoder into the AC servomotor 18 and detect the moving position of the table 6 by the computer 54 based on the pulse signal output from the encoder.
[0030]
Next, a coating method using the die coater 1 which is a coating apparatus according to the present invention will be described.
[0031]
First, when the origin return of each operating part in the coating apparatus is performed, the table 6 and the die 30 move to the standby position (origin position). At this time, the coating liquid 114 is already filled from the coating liquid tank 112 to the die 30, and 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. ing.
[0032]
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, the association of 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 lifting mechanism, that is, the so-called origin detection of the discharge port surface 74 is simultaneously executed and completed. Thereby, 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.
[0033]
After this preparation operation is completed, lift pins (not shown) are raised on the surface of the table 6, and when the substrate A is placed on the upper part thereof from the transfer machine (not shown), the lift pins are lowered and the substrate A is placed on the upper surface of the table 6. Place and adsorb.
[0034]
Next, the table 6 is moved at a predetermined speed, and is stopped when the coating start portion of the substrate A comes directly under the discharge port of the die 30. The substrate thickness of the substrate A is measured by a thickness sensor (not shown) in the stop state, and the value to be lowered of the die 30 is calculated from the thickness and the clearance given as a condition in advance, and the next position is obtained. The die 30 is lowered.
[0035]
On the other hand, the piston pump 120 has lowered the piston 128 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. is there. Then, the suction valve 126 is closed and the discharge valve 122 is opened. After confirming the clearance setting, the piston 128 is raised and the coating liquid 114 is fed into the die 30. After the start of the coating liquid feeding operation of the piston pump 120, the timer in the computer 54 starts, and after a predetermined time, a start signal is output from the computer to the AC servo motor of the table 6, and the table 6 starts moving at the coating speed. Then, application is started.
[0036]
When the coating end portion of the substrate A comes to a position near the discharge port of the die 30, a signal is outputted from the computer 54, the piston pump 120 is stopped and the die 30 is raised, and the coating liquid is completely covered from the substrate.
[0037]
On the other hand, the table 6 continues to move, stops when the substrate A reaches the end point 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 process. When the delivery to the unloader is completed, the table 6 lowers the lift pins and returns to the home position.
[0038]
During this time, the piston pump 120 performs a suction operation to newly fill the coating liquid 114 from the tank 112. Then, waiting for the next substrate A to come, the same operation is repeated.
[0039]
With the above application operation, the following application method is implemented to improve the response of discharge start / stop at the start and end of application, and to significantly reduce the defective film thickness where the film thickness does not reach a certain value. To do.
[0040]
The preparation operation of the piston pump 120 and the die 30 is exactly the same as the coating method described above until the substrate A is transferred to the table 6 and sucked. The coating thickness of the substrate A is measured in advance, and the die 30 is lowered to a position where a clearance is given accordingly. On the other hand, in the coating liquid supply unit 100, the cylinder 124 of the piston pump 120 is filled with the coating 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 is closed. 128 is in a stopped state.
[0041]
When the lowering of the die 30 is completed, the movement of the table 6 is started, and at the same time, the piston 128 starts to rise and reaches a predetermined constant speed, and the coating liquid 114 is returned to the tank 112. Next, when the coating start portion of the substrate A comes near the discharge port of the die 30, the discharge valve 122 is opened, the coating liquid is discharged from the die 30, and coating is started. Is closed, and a predetermined amount of coating solution is continuously discharged from the die 30 to continue coating. While both the table 6 and the piston 128 are operating at a predetermined constant speed, the additional pressure in the tank 112 is released and returned to normal pressure. When the application end portion of the substrate A comes near 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 decelerates and stops after the suction valve 126 is opened. Then, the die 30 is raised at the same timing as when the discharge of the coating liquid is stopped, and the coating liquid is completely reached from the substrate. Thereafter, the substrate is transferred to the drying process in the same manner as the above-described coating operation, and the table 6 and the piston pump 120 perform the origin return operation to prepare for the next substrate.
[0042]
In the above description of the present invention, an apparatus for cleaning the discharge port surface of the die is not shown, but means for cleaning the discharge port surface such as wiping or cleaning with a cleaning liquid may be added to the die coater. . As a result, since the application can be started in a state in which the discharge port surface of the die is always cleaned, the film thickness profile of the application start part can be easily controlled to a desired one.
[0043]
The coating liquid to which the present invention can be applied has a viscosity of 1 cps to 100,000 cps, desirably 10 cps to 50,000 cps, and Newtonian is preferable from the viewpoint of coating properties, but it can also be applied to a coating liquid having thixotropy. As the substrate A, in addition to glass, a metal plate such as aluminum, a ceramic plate, a silicon wafer, or the like may be used. Further, as application conditions to be used, the clearance (with respect to what is necessary) is 40 to 500 μm, more preferably 80 to 300 μm, and the application speed is 0.1 m / min to 10 m / min, more preferably 0.5 m / min. -6 m / min, the lip gap of the die is 50 to 1000 μm, more preferably 100 to 600 μm, and the coating thickness is 5 to 400 μm, more preferably 20 to 250 μm.
[0044]
In the above embodiment example, the constant capacity supply using the piston pump 120 and the constant pressure supply operation using the constant capacity supply operation and the constant pressure supply by the pressure feeding are shown, but only the constant pressure supply by the pressure feeding using the piston pump according to the present invention. You may apply | coat. The air pressure for constant pressure supply is 0.01 to 1 MPa, more preferably 0.05 to 0.5 MPa.
[0045]
As the suction valve 126 and the discharge valve 122, any valves other than a ball valve, such as a diaphragm valve, a tube valve, a plug valve, and a needle valve, may be used as long as they satisfy the function as a two-way valve. . As these materials, in addition to metals such as stainless steel, ceramics, resins such as Teflon and polypropylene, and those partially coated with ceramics, Teflon, etc. may be used.
[0046]
Furthermore, the material of the cylinder 124 and the piston 128 is preferably a metal such as stainless steel, a resin such as ceramics or Teflon, glass, or the like. The inner diameter of the cylinder 124 and the moving stroke amount of the piston 128 may be determined from the necessary storage amount determined from the coating amount, but the inner diameter of the cylinder 124 is 5 to 100 mm, preferably 10 to 50 mm, and the moving stroke amount of the piston 128 is 20 to 500 mm. The thickness is preferably 40 to 300 mm. Further, as the sealing material 130, in addition to a rubber O-ring such as silicon rubber, Kalrez, Viton, EPDM or the like, a resin such as Teflon, a mechanical seal that can be self-sealed by internal pressure, a V-ring, or the like may be used.
[0047]
As an object of the display member manufacturing apparatus according to the present invention, a color filter or the like used for a liquid crystal display is preferable in addition to a back plate and a front plate of a plasma display.
[0048]
【Example】
The effects of the present invention will be specifically described below with reference to examples.
Example 1
After a photosensitive silver paste is 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 × thickness of 2.8 mm, the photosensitive silver paste is exposed to a thickness of 5 μm, exposed using a photomask, and subjected to development and baking processes. Striped 1920 silver electrodes were formed at a pitch of 220 μm. A glass paste made of glass and a binder was screen-printed on the electrode and then baked to form a dielectric layer. Next, a stainless 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, for the piston pump 120 of the coating liquid supply unit 100, a stainless steel cylinder having an inner diameter of 40 mm was used for the cylinder 124, a suction valve 126, and a stainless steel air operated two-way ball valve for the discharge valve 122, respectively. 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 20000 cps composed of 60% glass powder and a photosensitive organic component. The discharge valve 122 was closed, the suction valve 126 was opened, 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 was 350 μm. At this time, after the piston 128 is moved upward at a speed of 0.9 mm / sec (equivalent to 1.15 cc / sec), the substrate is moved at a speed of 0.5 m / min, and the position 6 mm from the top of the substrate is the die discharge port. When it came directly below, the discharge valve 122 was opened, and after 1 second, the suction valve 126 was closed, and the coating of the photosensitive glass paste was started from a position 10 mm from the top of the substrate. During the application, the additional pressure of the tank 112 is returned to the atmospheric pressure, and when the position of the substrate 456 mm from the top is just below the die, the suction valve 126 is opened, the discharge valve 122 is closed, and the discharge is stopped. The die was also raised to completely cut the glass paste from the substrate. The piston 128 decelerated and stopped after the suction valve 126 was opened. Thus, the coating could be completed at a position of 460 mm from the top of the substrate. Next, the substrate on which this coating was completed was taken out with 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 is measured across the coating direction, it is as shown by the solid line in FIG. 3, where the steady portion is the target 140 μm ± 3 μm, and the coating start and end portions that do not fall within this thickness range are each 10 mm or less. Confirmed to be. The broken line in FIG. 3 is applied using the conventional piston pump of FIG. 4 under the same coating thickness and speed conditions, and it is clear that the film thickness defects at the start and end of coating are considerably improved. became.
[0049]
The substrate was then exposed using a photomask designed to form barriers between adjacent electrodes, and developed and fired to form barriers. The shape of the partition wall was a pitch of 220 μm, a line width of 30 μm, and a height of 130 μm, and the number of partition walls in each region was 1921. Thereafter, phosphor pastes of R, G, and B were sequentially applied by screen printing, dried at 80 ° C. for 15 minutes, and finally baked at 460 ° 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 plasma display back plate and the front plate were put together, sealed, sealed with a mixed gas of Xe 5% and Ne 95%, and a driving circuit was connected to obtain a plasma display.
[0050]
【The invention's effect】
Since the piston pump of the present invention has a structure that can discharge the coating liquid only in one direction, there is no staying portion, and the replacement and cleaning of the coating liquid can be performed reliably in a short time.
[0051]
Furthermore, because it has a configuration that can be used in combination with constant volume supply and constant pressure supply, it is possible to improve the discharge start response of the coating liquid and to eliminate the change in the discharge amount due to the change in viscosity. The coating apparatus and the coating method that have been used can minimize the film thickness defective portion at the coating start portion and can extremely reduce the film thickness unevenness of the steady portion over a long period of time.
[0052]
In addition, since the liquid can be continuously supplied at a constant pressure even though it is a constant capacity intermittent pump, replacement and cleaning of the coating liquid in the coating liquid supply line such as a die or pipe is shorter than the constant capacity intermittent supply. Can be implemented.
[0053]
Furthermore, since the discharge of the coating liquid from the die can be stopped instantaneously by switching the valve, the defective film thickness portion at the coating end portion can be minimized.
[0054]
High-quality plasma display and display member are industrially produced with high productivity by the manufacturing apparatus and manufacturing method of the plasma display or display member using the piston pump and the coating device and the coating method having the above excellent effects. Can be produced.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a die coater according to an embodiment of the present invention.
2 is a schematic configuration diagram showing the die coater of FIG. 1 including a coating solution supply system. FIG.
FIG. 3 is a comparison diagram of coating thicknesses of an example in which coating film thickness profiles are compared by the present invention and a conventional coating method.
FIG. 4 is a cross-sectional view schematically showing a conventional piston pump.
[Explanation of symbols]
1: Die coater
2: Base
6: Table
10: Adsorption 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

Claims (6)

A coating liquid supply apparatus for supplying a coating liquid applicator, and the applicator, coating device and said object having a discharge port for the coating liquid supplied from the coating liquid supply apparatus extending in one direction for ejecting the object to be coated member And a moving means for forming a coating film on the coated member by relatively moving at least one of the coating members. The coating liquid supply device supplies the coating liquid to the applicator. Constant volume supply means for supplying a constant volume , and a coating liquid in a supply tank connected to the upstream side of the constant volume supply means is pressurized at a constant pressure, and is applied in one direction through a fluid passage in the constant volume supply. A constant pressure supply means for supplying a constant pressure to the applicator, and further comprising a control means for controlling the operation by selecting a single operation or a combination of the constant capacity supply means and the constant pressure supply means. Coating equipment The constant-capacity supply means includes a cylinder that stores a fluid therein and has an outlet at an end thereof, and a piston that supplies fluid into and out of the cylinder by reciprocation, and each of the fluid is supplied to the cylinder and the piston. The coating apparatus according to claim 1, wherein the coating apparatus is a piston pump provided with a passage. An apparatus for manufacturing a plasma display or a display member, comprising the coating apparatus according to claim 1 . In the coating method of forming a coating film on the coated member by relatively moving at least one of the coating device and the coated member while discharging the coating liquid from a discharge port extending in one direction of the coating device, Regarding the supply of the coating liquid to the applicator , the constant volume supply by the constant volume supply means and the coating liquid in the supply tank connected to the upstream side of the constant volume supply means are applied at a constant pressure by the constant pressure supply means. a coating method and performing select a constant pressure supply and alone or in combination supplied to the applicator in one direction through the fluid passage of the inside of the constant volume supply means by applying. The coating method according to claim 4 , wherein the constant volume supply and the constant pressure supply are used together at the start or end of application of the application liquid to the application member of the applicator . A method for producing a plasma display or display member, comprising producing a plasma display or a display member using the coating method according to claim 4 or 5 .

Images