JP3714369B2 - Coating apparatus and coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus and a coating method particularly suitable for manufacturing a color filter for a color liquid crystal display.
[0002]
[Related background]
A color filter for a color liquid crystal display has a fine lattice pattern of three primary colors on its glass substrate. Such a lattice pattern is obtained by first forming a black coating film on a glass substrate, then repeating masking and etching processes, and sequentially forming red, blue, and green coating films on the glass substrate. .
[0003]
Therefore, a so-called coating process for forming a coating film of each color on a glass substrate is indispensable for manufacturing a color filter. Conventionally, spinners, bar coaters or roll coaters have been used as coating devices in such coating processes, but in recent years in order to reduce the consumption of coating liquid and improve the physical properties of the coating film. The use of a die coater has been studied.
[0004]
A die coater of this type is disclosed in, for example, Japanese Patent Laid-Open No. 4-346868. This known die coater forms a coating film on the surface of the member to be coated by discharging the coating liquid from the discharge port of the applicator onto the surface of the member to be coated and simultaneously moving the member to be coated at a constant speed. It is supposed to be. Here, as shown in FIG. 1, the film thickness of the coating film is determined by the moving speed of the member to be coated and the discharge flow rate of the coating liquid from the applicator. Specifically, when the moving speed of the member to be coated is constant, the film thickness of the coating film increases as the discharge flow rate of the coating liquid increases, for example, K to M (K <L <M), and vice versa. In addition, when the discharge flow rate of the coating liquid is constant, the film thickness of the coating film decreases as M to K as the moving speed of the member to be coated increases. Therefore, in order to keep the film thickness of the coating film constant, the discharge flow rate of the coating liquid and the moving speed of the member to be coated are kept constant.
[0005]
[Problems to be solved by the invention]
By the way, even if the member to be coated is moved and the coating liquid is discharged from the applicator, these moving speeds and discharge flow rates are indicated by Ts and Tp in FIG. 2 until reaching their steady state. Delay occurs. For this reason, in such a response delay period, that is, in a transition period until the moving speed and the discharge flow rate shift to the steady state, the steady state is between the discharge flow rate of the coating liquid and the moving speed of the member to be coated. The same relationship as in the case of the state is not maintained, and the coating film formed on the surface of the member to be coated does not have a desired constant value. Therefore, the coating film formed on the surface of the coated member from the start of the formation until the discharge flow rate and the moving speed both shift to the steady state is a defect in which the film thickness deviates from the normal value. It becomes a part.
[0006]
ThisThe invention has been made on the basis of the above-mentioned circumstances, and the object is to apply a coating apparatus and a coating method that can reduce the defective film thickness portion of the coating film as much as possible at the start of coating film formation., ThatThen, it is providing the manufacturing apparatus and manufacturing method of a color filter using these coating devices and methods.
[0007]
[Means for Solving the Problems]
  The above object is achieved by the present invention. The coating apparatus according to claim 1 is a supply means for supplying a coating liquid, an applicator for discharging the coating liquid supplied from the supply means, an applicator, and a member to be coated. A moving means for relatively moving at least one of the coating member, and when a coating film is formed on the surface of the member to be coated,Against applicatorIn the transition period until the relative moving speed of the coated member shifts to the steady state, the discharge flow rate of the coating liquidRate of changeIn order to make the rate of change of the relative movement speed of the member to be coated coincide with each otherThe discharge flow rate of the coating liquid from the applicator relative to the relative movement of the coating member according to the coating liquid discharge pattern prepared based on the acceleration characteristic of the relative movement speed measured in advanceAnd tuning means for controlling.
[0008]
  According to the coating apparatus of claim 1, the discharge flow rate and the relative flow rate are measured even in the transition period until the discharge flow rate of the coating liquid and the relative movement speed of the coated member shift to the steady state after the start of coating film formation. The moving speed isThemThe rates of change coincide with each other, and the relationship between the discharge flow rate of the coating liquid and the relative movement speed of the member to be coated is the same as that in the steady state. Therefore, in this case, a coating film having a desired film thickness is formed immediately after the start of the coating film formation.
[0009]
  In the case of the coating apparatus according to claim 1, the discharge pattern is determined by the pre-discharge pattern determined based on the clearance between the member to be coated and the applicator and the acceleration characteristic of the relative movement speed of the member to be coated with respect to the applicator. The response discharge pattern matches the change rate of the discharge flow rate of the coating liquid from the applicator and the change rate of the relative movement speed of the member to be applied.
[0012]
  Claim3The color filter manufacturing apparatus of claim1 or 2In this case, a color filter is manufactured using the coating apparatus.
  Claim4In this coating method, at least one of the applicator and the member to be coated is relatively moved while discharging the coating liquid from the applicator, thereby forming the coating film on the surface of the member to be coated. Discharge flow rate of coating liquid from the start of formation andAgainst applicatorIn order to make the change rate of the discharge flow rate of the coating liquid and the relative movement speed of the coated member coincide with each other in the transition period until the relative moving speed of the coated member shifts to a steady state,The discharge flow rate of the coating liquid from the applicator relative to the relative movement of the coating member according to the coating liquid discharge pattern prepared based on the acceleration characteristic of the relative movement speed measured in advanceIs controlling. Such claims4This coating method exhibits the same action as the coating apparatus of claim 1 described above.
[0013]
  In the case of the coating method according to claim 5, the discharge pattern is determined by the pre-discharge pattern determined based on the clearance between the member to be coated and the applicator and the acceleration characteristic of the relative movement speed of the member to be coated with respect to the applicator. The response discharge pattern matches the change rate of the discharge flow rate of the coating liquid from the applicator and the change rate of the relative movement speed of the member to be applied.
[0014]
  Claim6The manufacturing method of the color filter of claim4 or 5A color filter is manufactured using the coating method described in 1. In this case, a high-quality color filter is obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 3, there is shown a coating apparatus, so-called die coater, which is applied to manufacture a color filter for a color liquid crystal display. This die coater includes a base 2, and a pair of guide groove rails 4 parallel to each other are provided on the base 2. These guide groove rails 4 are provided with a stage 6 whose upper surface is configured as a suction surface, and the stage 6 can reciprocate horizontally on the guide groove rail 4 via a pair of slide legs 8. ing. The stage 6 is formed of a material such as glass reinforced fiber plastic (FRP), glass reinforced fiber metal (FRM), or aluminum, and the weight thereof is reduced.
[0016]
  A casing 12 extending along the guide groove rails 4 is provided between the pair of guide groove rails 4, and a feed mechanism for the stage 6 is built in the casing 12. This feed mechanism is a ball screw as shown in FIG.BecomeThe feed screw 14 is screwed into a nut-shaped connector 16 and extends through the connector 16. A part of the connector 16 protrudes from the casing 12 through a slot (not shown) formed in the side surface of the casing 12 and is fixed to the lower surface of the stage 6.
[0017]
Both ends of the feed screw 14 are rotatably supported through bearings (not shown), and a stage motor 18 composed of an AC servo motor is connected to one end thereof. The stage motor 18 can reciprocate the stage 6 by rotating the feed screw 14 forward and backward. When the stage 6 reciprocates, a part of the connector 16 described above moves in the slot of the casing 12.
[0018]
As apparent from FIG. 3, an inverted L-shaped sensor column 20 is erected on one end side of the upper surface of the base 2, and the tip of the sensor column 20 extends upward between the pair of guide groove rails 4. An electric lift actuator 21 is attached to the tip of the sensor column 20, and a thickness sensor 22 is attached to the lift actuator 21 downward. The thickness sensor 22 is based on the light source that emits the measurement light toward the measurement target, the light receiving unit that receives the reflected light of the measurement light from the measurement target, and the thickness of the measurement target based on the incident position of the reflected light on the light receiving unit. And an arithmetic circuit for calculating. Specifically, when the glass substrate A, which is a single-wafer member, is placed on the stage 6 as a member to be coated, the thickness sensor 22 is lowered from the glass substrate A to a predetermined height level. In this state, measurement light is emitted from the light source of the thickness sensor 22, and the measurement light is reflected by the upper and lower surfaces of the glass substrate A, respectively, and these reflected light enters the light receiving unit. The arithmetic circuit obtains a difference in incident position in the reflected light, and outputs a detection signal corresponding to the thickness of the glass substrate A based on this difference. The thickness sensor 22 is not limited to the type described above, and a laser displacement meter, an electronic micro displacement meter, an ultrasonic thickness meter, or the like can also be used.
[0019]
Further, an inverted L-shaped die column 24 similar to the sensor column 20 is erected at the center of the upper surface of the base 2, and the tip of the die column 24 is also located above the pair of guide groove rails 4. Has been placed. A lifting mechanism 26 is provided at the tip of the die support 24, but the lifting mechanism 26 is not shown in detail in FIG. Briefly describing the elevating mechanism 26, the elevating mechanism 26 includes an elevating bracket, and this elevating bracket is attached to a pair of vertical guide rods so as to be movable up and down. A feed screw composed of a ball screw extends between the vertical guide rods. The feed screw is screwed into a nut-like connector and extends through the connector. The pair of vertical guide rods and the feed screw are accommodated in a casing 28 (FIG. 3) of the elevating mechanism 26, the upper and lower ends of the pair of vertical guide rods are supported by the casing 28, and the upper and lower ends of the feed screw are the casings. 28 is rotatably supported. A part of the connector of the feed screw protrudes through a slot of the casing 28 and is connected to the above-described lifting bracket. The upper end of the feed screw is connected to the output shaft of the AC servo motor 30, and the AC servo motor 30 is attached to the upper surface of the casing 28. Therefore, the AC servo motor 30 can move the lifting bracket up and down by rotating the feed screw forward and backward.
[0020]
A die holder 32 is attached to the lifting bracket via a horizontal support shaft (not shown). The die holder 32 has a U-shape that opens toward the sensor column 20, and extends above the pair of guide groove rails 4 in a direction perpendicular to the guide groove rails 4. The support shaft of the die holder 32 is rotatably supported by the lifting bracket, and the die holder 32 can rotate in a vertical plane around the support shaft.
[0021]
A horizontal bar 36 is attached to the lifting bracket, and the horizontal bar 36 extends along the die holder 32 above the die holder 32. Electromagnetically operated linear actuators 38 are respectively attached to both ends of the horizontal bar 36, and these linear actuators 38 have telescopic rods protruding from the lower surface of the horizontal bar 36. The lower ends of the telescopic rods of the linear actuators 38 are in contact with the upper surfaces of both ends of the die holder 32, thereby holding the die holder 32 horizontally.
[0022]
An applicator, a so-called slit die 40 is mounted in the die holder 32, and the slit die 40 is supported by the die holder 32 at both ends thereof. As shown in FIG. 4, a coating solution supply hose 42 extends from the slit die 40, and the tip of the supply hose 42 is connected to a syringe pump 44. Specifically, the syringe pump 44 has an electromagnetic switching valve 46 composed of a three-way valve, and a supply hose 42 is connected to a supply port of the electromagnetic switching valve 46. A suction hose 48 extends from the suction port of the electromagnetic switching valve 46, and the suction hose 48 is connected to a tank 50 for coating liquid.
[0023]
  The pump body 52 of the syringe pump 44 has its pump chamber connected to the inlet / outlet port of the electromagnetic switching valve 46, and the pump chamber is switched to one of its supply port and suction port, that is, the supply hose 42 by the switching operation of the electromagnetic switching valve 46. One of the suction hoses 48 is selectively connected. The plunger of the pump body 52 is in a state where its rotation is prevented, and a feed screw is connected to the plunger rod (not shown).53Is screwed coaxially. This feed screw is connected to the output shaft of a pump motor 55 comprising an AC servomotor. Therefore, the pump motor 55 can reciprocate the plunger of the pump body 52 by rotating the feed screw forward and backward.
[0024]
The electromagnetic switching valve 46 and the pump motor 55 of the syringe pump 44 described above are electrically connected to a computer 54, and control signals from the computer 54 are received to control their switching operation and driving. Further, the elevator actuator 21 and the thickness sensor 22 described above are also electrically connected to the computer 54.
[0025]
Further, in order to synchronize the operation of the syringe pump 44 with the reciprocation of the stage 6, a sequencer 56 is also electrically connected to the computer 54. The sequencer 56 is connected to the stage motor 18 of the stage 6 and the AC on the lifting mechanism 26 side. Servomotor 30 and the like are sequence-controlled. For the sequence control, the sequencer 56 includes a signal indicating the operating state of the stage motor 18 and the AC servo motor 30, signals from a plurality of position sensors 59 for detecting the moving position of the stage 6, and the operation of the slit die 40. A signal from a sensor (not shown) for detecting the state is input, while a signal indicating a sequence operation is output from the sequencer 56 to the computer 54. Instead of using the position sensor 59, it is also possible to incorporate a rotary encoder in the stage motor 18 and detect the moving position of the stage 6 inside the sequencer 56 based on the pulse signal output from the rotary encoder. It is. It is also possible to incorporate control by the computer 54 into the sequencer 56 itself.
[0026]
Further, although not shown in FIG. 3, the die coater is provided with a loader for supplying the glass substrate A onto the stage 6 and an unloader for removing the glass substrate A from the stage 6, respectively. For example, a cylindrical coordinate system industrial robot can be used as a main component of the loader and unloader.
[0027]
In the slit die 40 described above, the front lip 58 and the rear lip 60 face each other in the reciprocating direction of the stage 6 through shims, and the front lip 58 and the rear lip 60 are integrated by a connecting bolt (not shown). Are connected to each other. A manifold 62 is formed in the slit die 40, and the manifold 62 communicates with a slit secured by a shim. The manifold 62 and the slit extend in the width direction of the slit die 40 (a direction orthogonal to the reciprocating direction of the stage 6), and the slit opens on the lower surface of the slit die 40, and this opening serves as a discharge port. The manifold 62 is always connected to the supply hose 42 described above through an internal passage (not shown) of the slit die 40 and can receive the supply of the coating liquid through the supply hose 42.
[0028]
Next, referring to FIG. 5, a block diagram for explaining the function of the computer 54 regarding the operation control of the syringe pump 44 performed in the transition period described later from the start of the formation of the coating film on the glass substrate A. It is shown. The microprocessor (MPU) 64 of the computer 54 is electrically connected to the pump motor 55 and the sequencer 56 of the syringe pump 44 as is apparent from the above description, and is supplied to the stage 6 from the sequencer 56 to the MPU 64. A moving speed in a steady state, that is, a stage speed V, a clearance H to be secured between the glass substrate A on the stage 6 and the discharge port of the slit die 40 are given. The MPU 64 can be given a film thickness T of the coating film to be formed on the glass substrate A, and a memory 66 such as a RAM or a ROM is connected thereto.
[0029]
The memory 66 stores in advance a discharge pattern of the coating liquid from the syringe pump 44, specifically, a discharge pattern of the coating liquid from the discharge port of the slit die 40, and the MPU 64 follows the discharge pattern according to the discharge pattern. That is, the drive of the pump motor 55 is controlled.
Here, in addition to the above-described film thickness T and clearance H, the ejection pattern has a start-up characteristic (from the start of movement of the stage 6 to the stage speed V reaching the steady state, that is, the stage speed V). Acceleration characteristics). The start-up characteristics regarding the moving speed of the stage 6 can be obtained by actually measuring in advance. Various discharge patterns are prepared in advance based on the film thickness T, clearance H, and startup characteristics at the stage speed in order to cope with changes in the film thickness T, clearance H, and stage speed. And stored in the memory 66.
[0030]
Specifically, as shown by a solid line in FIG. 6, the discharge pattern is divided into a pre-discharge pattern determined based on the clearance H and a response discharge pattern determined based on the startup characteristics of the stage 6. ing. In the pre-discharge pattern, the pump motor 55 of the syringe pump 44 is driven to rapidly discharge the coating liquid from the slit die 40 by a predetermined amount corresponding to the clearance H. In detail, as will be described later, the coating liquid is discharged from the slit die 40 as rapidly as possible so as to form a minimum liquid reservoir enough to generate a so-called meniscus between the discharge port of the slit die 40 and the glass substrate A. .
[0031]
In the response discharge pattern following the pre-discharge pattern, the syringe pump 44 is set so that the change rate of the discharge flow rate of the coating liquid from the slit die 40 matches the start-up characteristic of the stage 6, that is, the change rate of the moving speed of the stage 6. The drive of the pump motor 55 is controlled. In FIG. 6, the broken line indicates the start-up characteristic when the movement of the stage 6 is started.
[0032]
Next, one process relating to the manufacture of the color filter, that is, a coating method for forming a coating film on the glass substrate A using the above-described die coater will be described.
First, the origin return of each operation part in the die coater is performed, and the stage 6 is positioned at one end of the base 2 as shown in FIG. At this time, the coating liquid in the tank 50 is guided to the manifold 62 and the slit of the slit die 40 through the suction hose 48, the syringe pump 44, and the supply hose 42, and the path of the coating liquid from the tank 50 to the slit is applied. It is in a state filled with liquid. More specifically, as an application preparation operation, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 and the suction hose 48, and the pump body 52 is applied to the pump chamber on the tank 50 side. In this state, the electromagnetic switching valve 46 is switched to connect the pump main body 52 and the supply hose 42.
[0033]
When the glass substrate A is supplied onto the stage 6 by a loader (not shown), the glass substrate A is sucked and held while being positioned on the stage 6. When the loading of the glass substrate A is completed in this way, the thickness sensor 22 described above is lowered to a predetermined position above the glass substrate A, and at this lowered position, the thickness sensor 22 is the thickness of the glass substrate A as described above. And the detection signal is output to the computer 54.
[0034]
Thereafter, the stage 6 is moved forward toward the slit die 40, and when the film formation start line (for example, the front edge of the glass substrate A) on the glass substrate A reaches below the discharge port in the slit die 40. Thus, the forward movement of the stage 6 is temporarily stopped. In this state, the slit die 40 is lowered in consideration of the already detected thickness of the glass substrate A, and the clearance H is accurately ensured between the discharge port of the slit die 40 and the glass substrate A.
[0035]
On the other hand, on the computer 54 side, part of the pump control routine shown in FIG. 7, that is, steps S 1 and S 2 are executed by the MPU 64. That is, the MPU 64 reads the clearance H set as described above, the film thickness T of the coating film to be formed, and the stage speed V, and the discharge pattern described above is set based on these data.
[0036]
After setting the clearance H, the drive of the pump motor 55 of the syringe pump 44 is controlled based on the discharge pattern (step S3 in FIG. 7). That is, as is apparent from the above description, the pump motor 55 is driven and controlled based on the pre-discharge pattern of the discharge pattern, whereby the coating liquid is uniformly and rapidly applied from the discharge port of the slit die 40 on the glass substrate A. It is discharged along the formation start line. As a result, a liquid reservoir C (see FIG. 4) having a meniscus is immediately formed between the glass substrate A and the discharge port of the slit die 40.
[0037]
When the pre-discharge pattern is completed, drive control of the pump motor 55 based on the response discharge pattern is started, and the movement of the stage 6 is started at this time (time t0 in FIG. 6). Accordingly, the coating film D (see FIG. 4) starts to be formed on the glass substrate A from time t0. Thereafter, the stage 6 gradually increases its moving speed, reaches the stage speed V at time t1 in FIG. 6, and thereafter is maintained at the steady stage speed V.
[0038]
The period from the time point t0 to the time point t1 corresponds to a response discharge pattern period. During this period, the coating liquid is discharged onto the glass substrate A from the discharge port of the slit die 40 according to the response discharge pattern as described above. Is done. That is, in the response discharge pattern, the change rate of the discharge flow rate in the coating liquid is matched with the change rate of the moving speed of the stage 6. Accordingly, the discharge flow rate of the coating liquid increases while being synchronized with the change in the moving speed of the stage 6, and finally reaches a steady discharge flow rate Q determined by the stage speed V and the film thickness T of the coating film. To reach. Thereafter, the discharge flow rate of the coating liquid from the slit die 40 is maintained at the steady discharge flow rate Q. Here, the time when the moving speed of the stage 6 reaches the stage speed V and the time when the discharge flow rate of the coating liquid reaches the steady flow rate Q coincide with each other as apparent from FIG.
[0039]
As is apparent from the above description, the discharge flow rate of the coating liquid and the moving speed of the stage 6 even immediately after the stage 6 starts moving, even in the transitional period until the moving speed reaches the steady stage speed V. And the relationship between the movement of the stage 6 and the discharge flow rate of the coating liquid are in a steady state. As a result, the coating film D formed on the glass substrate A as shown in FIG. 8 is maintained at the film thickness T immediately after the start of the formation. Note that the arrows in FIG. 8 indicate the moving direction of the stage 6.
[0040]
On the other hand, if the discharge flow rate of the coating liquid from the slit die 40 is not controlled according to the above-described response discharge pattern in the transition period until the moving speed of the stage 6 shifts to the steady state, as shown by the broken line in FIG. In addition, the first part of the coating film formed on the glass substrate A becomes a defective part X whose film thickness is larger than the normal film thickness T over a long distance. This is a phenomenon that occurs when the time until the discharge flow rate of the coating liquid reaches the steady flow rate Q is shorter than the delay time until the stage 6 reaches the steady state, and until the stage 6 reaches the steady state. This is because the discharge flow rate of the coating liquid from the slit die 40 becomes excessive during the transition period.
[0041]
In this regard, as described above, when the movement of the stage 6 is started and at the same time the discharge flow rate of the coating liquid is controlled according to the response discharge pattern, the coating film D can be immediately formed with the regular film thickness T. In this case, the defective portion Y of the coating film D only shows a deviation from the optimum liquid pool amount when forming with the pre-discharge pattern, and is short enough to be ignored. Here, the pre-discharge pattern can be completed in a short time by maximizing the discharge flow rate of the coating liquid from the syringe pump 44, which can contribute to a reduction in cycle time.
[0042]
On the other hand, if the cycle time limit is small, even if the pre-discharge pattern is made the same as the response discharge pattern and the time from the pre-discharge pattern to t0 is adjusted to ensure the optimum liquid pool amount, the defective portion Y Can be minimized.
Here, for example, when the stage speed V in a steady state is set to 3 m / min, the rising time constant of the stage 6 is set to 50 msec, and the discharge flow rate Q of the syringe pump 44 is set to 0.3 cc / s, the response discharge pattern of the syringe pump 44 is set. When optimized, the defective portion whose film thickness exceeded ± 5% of T was 3 mm or less, and when not optimized, the defective portion increased to 20 mm. Furthermore, since the weight of the stage 6 is reduced as described above, the acceleration of the stage 6 can be increased, the time required for the response discharge pattern can be greatly shortened, and the cycle time can be reduced. it can.
[0043]
As described above, when the coating film D having the film thickness T is formed on the glass substrate A, as the stage 6 proceeds, there is a formation end line for ending the formation of the coating film D on the glass substrate A. When the discharge port of the slit die 40 is reached, at this time, the discharge operation of the syringe pump 40, that is, the discharge of the coating liquid from the discharge port of the slit die 40 is stopped (see step S4 in FIG. 7). Here, even if the discharge of the coating liquid is stopped, since the liquid pool C exists between the glass substrate A and the discharge port of the slit die 40, the liquid pool C is applied on the glass substrate A. A coating film is formed while consuming the liquid (squeegee).
[0044]
At the same time as the discharge of the coating liquid from the slit die 40 is stopped, the syringe pump 44 performs a slight suction operation of the coating liquid, and the coating liquid in the slit of the slit die 40 is slightly sucked back to the manifold 62 side. .
At the same time, the slit die 40 is raised to the original position, while the syringe pump 44 discharges the coating liquid by the amount of the previous suction operation, and the residual air in the slit die 40 is eliminated. The Thereafter, the syringe pump 44 waits after performing the above-described application preparation operation. That is, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 and the suction hose 48, and the pump body 52 sucks a predetermined amount of the coating liquid on the tank 50 side into the pump chamber, In this state, the electromagnetic switching valve 46 is switched to connect the pump body 52 and the supply hose 42. In addition, the coating liquid adhering to the lower surface of the slit die 40 is wiped off by a cleaner (not shown) at the rising position of the slit die 40.
[0045]
Even when the discharge of the coating liquid from the slit die 40 is stopped, the forward movement of the stage 6 is continued, and the stage 6 is stopped when the stage 6 reaches the end of the pair of guide groove rails 4. In this stopped state, the glass substrate A on which the coating film D is formed is released from the suction, removed from the stage 6 by an unloader (not shown), and supplied to the next step. Thereafter, the stage 6 is returned to the initial position shown in FIG. 3, thereby completing a series of coating steps. At the initial position, the stage 6 stands by until a new glass substrate A is loaded.
[0046]
The present invention is not limited to the above-described embodiment, and various modifications can be made. In one embodiment, the glass substrate A, which is a member to be coated, is moved through the stage 6, but the glass substrate A may be fixed and the slit die 40 may be moved, or these may be moved together. May be. In short, a relative movement speed may be given between the glass substrate A and the slit die 40.
[0047]
In one embodiment, the discharge flow rate of the coating liquid from the slit die 40 is synchronized with the startup characteristic on the stage 6 side, that is, the drive of the pump motor 55 in the syringe pump 44 is controlled. On the contrary, the same effect can be obtained by controlling the moving speed of the stage 6 with respect to the rising characteristic of the discharge flow rate from the slit die 40 or by controlling both at the same time.
[0048]
Referring now to FIG. 9, a diaphragm pump 68 that is used in place of the syringe pump 44 is shown. The diaphragm pump 68 includes a pump housing 70, and a hemispherical upper pump chamber 72 and a lower pressure chamber 74 are formed in the pump housing 70. The pump chamber 72 and the pressure chamber 74 are partitioned by a diaphragm 76, and the pressure chamber 74 is partitioned by a diaphragm 76 and a piston 78. The pressure chamber 74 is always filled with hydraulic fluid. The piston 78 is connected to the pump motor 55 through a mechanism similar to the case where the piston rod is the syringe pump 44. A suction hose 48 is connected to the lower portion of the pump chamber 72, and an electromagnetic on-off valve 80 is inserted in the suction hose 48. On the other hand, a supply hose 42 is connected to the top of the pump chamber 72, and an electromagnetic open / close valve 82 is also inserted in the supply hose 42.
[0049]
According to the diaphragm pump 68 described above, the electromagnetic on-off valve 82 of the supply hose 42 is closed, while the electromagnetic on-off valve 80 of the suction hose 48 is opened and the piston 78 is lowered, so that the diaphragm 76 follows the volume change. It is deformed to the suction side, and the coating liquid can be sucked into the pump chamber 72 from the tank 50. Thereafter, the piston 78 can be raised with the electromagnetic on-off valve 80 closed and the electromagnetic on-off valve 82 opened. For example, the diaphragm 76 is deformed to the discharge side according to the volume change at this time, and the coating liquid in the pump chamber 72 can be discharged toward the slit die 40.
[0050]
There is no portion of the diaphragm pump 68 that is worn like the syringe pump 44. The piston 78 becomes a wear part. However, since the pump chamber 72 and the pressure chamber 74 are partitioned by the diaphragm 76, impurities such as wear powder are not mixed into the coating liquid in the pump chamber 72. Therefore, the formed coating film D does not have a defect due to the impurities.
[0051]
Further, with respect to the suction operation of the coating liquid, the suction port and the discharge port are separated, and furthermore, since the coating liquid is sucked into the bottom of the pump chamber 72, the coating liquid is first-in, first-out in the pump chamber 72, The coating liquid does not stay in the pump chamber 72. If the coating liquid remains, the coating particles solidify, and when the solidified product is supplied toward the slit die 40, a defect may occur in the coating film due to the solidified product. is there.
[0052]
Further, since the supply hose 42 is connected to the top of the pump chamber 72, there is an advantage that the air in the pump chamber 72 can be easily vented.
[0053]
【The invention's effect】
  As explained above, claim 1, 2,4,5According to this coating apparatus and coating method, at the start of coating film formation, the discharge flow rate of the coating liquid from the coating device and the relative movement speed of the coated member are synchronized with each other in the transition period until they reach a steady state. Therefore, immediately after the start of the formation of the coating film, the coating film can be formed with a desired film thickness, and the defective film thickness portion can be greatly shortened.
[0055]
ContractClaim3, 6According to this color filter manufacturing apparatus and method, it is possible to efficiently produce a color filter and to improve its quality.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the moving speed of a member to be coated and the discharge flow rate of a coating liquid with respect to the film thickness of a coating film.
FIG. 2 is a graph showing responsiveness until movement of a member to be coated and a discharge flow rate of a coating liquid reach a steady state when formation of a coating film is started.
FIG. 3 is a perspective view showing a die coater.
4 is a diagram showing a schematic configuration of the die coater of FIG. 1 together with a coating liquid supply system.
5 is a block diagram for explaining functions of a computer with respect to the pump motor of FIG. 4. FIG.
FIG. 6 is a graph showing synchronous control between the stage speed and the discharge flow rate.
FIG. 7 is a flowchart showing a control routine of the pump motor.
8 is a view showing a part of a coating film formed on a glass substrate A. FIG.
FIG. 9 is a cross-sectional view showing a diaphragm pump.
[Explanation of symbols]
6 stages
14 Feed screw
18 stage motor
40 Slit die (applicator)
42 Supply hose
44 Syringe pump
46 Solenoid switching valve
48 Suction hose
52 Pump body
54 Computer (tuning means)
55 Pump motor
56 Sequencer
64 MPU
66 memory
68 Diaphragm pump
A Glass substrate (Coating member)

Claims (6)

Supply means for supplying a coating liquid;
An applicator for discharging the coating liquid supplied from the supply means;
In a coating apparatus comprising a moving means for relatively moving at least one of the coating device and the member to be coated,
When a coating film is formed on the surface of the coated member, the discharge flow rate of the coating liquid of the coating device and the relative movement speed of the coated member with respect to the coating device are in a steady state after the start of the formation of the coating film, respectively. Acceleration characteristics of the relative movement speed measured in advance so that the change rate of the discharge flow rate of the coating liquid from the applicator and the change rate of the relative movement speed of the member to be coated coincide with each other in the transition period until the transition. A coating apparatus comprising a tuning means for controlling a discharge flow rate of the coating liquid from the applicator with respect to relative movement of the coating member in accordance with a coating liquid discharge pattern prepared based on the above . The discharge pattern is a response discharge determined by a pre-discharge pattern determined based on a clearance between the member to be coated and the applicator and an acceleration characteristic of a relative movement speed of the member to be coated with respect to the applicator. Pattern and
2. The coating apparatus according to claim 1, wherein the response ejection pattern matches a rate of change in the discharge flow rate of the coating liquid from the applicator and a rate of change in the relative movement speed of the member to be coated. . An apparatus for producing a color filter, comprising the coating apparatus according to claim 1 . In the coating method of forming a coating film on the surface of the coated member by relatively moving at least one of the coating device and the coated member while discharging the coating liquid from the coating device,
Wherein at transition period after start of forming the coating film to a relative moving speed of the object to be coated member for discharge flow rate and the applicator of the coating fluid from the applicator is shifted to the respective steady state, discharge of the coating liquid In order to make the change rate of the flow rate and the change rate of the relative movement speed of the member to be coated coincide with each other, according to the discharge pattern of the coating liquid prepared based on the acceleration characteristic of the relative movement speed measured in advance, A coating method comprising controlling a discharge flow rate of the coating liquid from the coating device with respect to movement . The discharge pattern is a response discharge determined by a pre-discharge pattern determined based on a clearance between the member to be coated and the applicator and an acceleration characteristic of a relative movement speed of the member to be coated with respect to the applicator. Pattern and
5. The coating method according to claim 4, wherein the response ejection pattern matches a rate of change in the discharge flow rate of the coating liquid from the applicator and a rate of change in the relative movement speed of the member to be coated. . A method for producing a color filter, wherein the coating method according to claim 4 or 5 is used.

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