JP4645926B2 - Coating head cleaning method and cleaning apparatus, and color filter manufacturing method and manufacturing apparatus using them - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to, for example, the manufacturing field of color filters for color liquid crystal displays, optical filters, printed circuit boards, integrated circuits, semiconductors, and the like. Specifically, the coating liquid is discharged onto the surface of a member to be coated such as a glass substrate. The present invention relates to a method and an apparatus for cleaning a coating head for forming a coating film, and a method for manufacturing a color filter and an apparatus for manufacturing the same using these methods and apparatuses.
[0002]
[Prior art]
A color filter for a color liquid crystal display has a fine lattice pattern of three primary colors on a glass substrate. Such a lattice pattern first forms a black coating film on a glass substrate, then red, blue, It is obtained by forming a green coating film.
[0003]
Therefore, for the production of a color filter, a coating process in which black, red, blue, and green coating liquids are coated on a glass substrate and a coating film is sequentially formed using these coating liquids is indispensable. In this type of coating process, a spinner, bar coater or roll coater has been used as a conventional coating apparatus. However, in order to reduce the consumption of the coating liquid and improve the physical properties of the coating film, it has been in recent years. Die coaters are starting to be used.
[0004]
An example of this type of die coater is disclosed, for example, in JP-A-6-339655. This known die coater has a slit die as a coating head, and forms a coating film on a member to be coated such as a substrate traveling in one direction while discharging a coating liquid from a discharge port of the slit die. ing.
[0005]
And, in order to apply repeatedly and stably to a single wafer such as a substrate with a die coater, it is possible to remove and clean the deposits such as coating liquid remaining around the discharge port before each application. Necessary. By cleaning the peripheral portion of the discharge port before application, it becomes possible to always start application in the same state, so that the application thickness distribution at the application start part can always be kept constant. Furthermore, since unnecessary foreign matter is also excluded from the periphery of the discharge port, application defects caused by these foreign matters, such as dropping of foreign matter onto the coating film, occurrence of streak defects due to contact with foreign matter immediately after application, etc. Can be prevented.
[0006]
As the cleaning means for the peripheral portion of the discharge port, which is indispensable when the above-mentioned substrate or the like is applied with a die coater, three types of cleaning means have been proposed.
[0007]
The first type is disclosed in Japanese Patent Application Laid-Open No. 7-168015, etc., and creates a cleaning tool that follows the shape of the tip of the slit die including the discharge port with a chemical-resistant polymer material, This cleaning tool is brought into sliding contact with the slit die in the longitudinal direction at the tip end of the slit die to remove excess coating liquid and the like adhering to the periphery of the discharge port.
[0008]
The second type wipes the periphery of the discharge port with a dust-free cloth moistened with a solvent as described in JP-A-7-80386 and the like.
[0009]
As described in JP-A-7-80386, JP-A-10-308338, JP-A-11-74179, and the like, the third type is provided near the discharge port by a dedicated cleaning liquid made of a solvent or the like. After washing off some extra deposits, it is dried with a drying gas or the like.
[0010]
[Problems to be solved by the invention]
The above three types of conventional means have the following problems.
First, in the first type means, since the cleaning tool is brought into sliding contact with the slit die, if cleaning is performed for a long time, the cleaning tool is worn and the effect of cleaning is reduced. There is a problem that the product is mixed into the coating film and the quality is lowered.
[0011]
Also, in the second type means, the dust-free cloth is brought into contact with the slit die to wipe the deposits, so that the dust-free cloth is worn away and particles are generated, resulting in a similar deterioration in the quality of the coated material.
[0012]
Further, in the third type of means, since solvent or the like is sprayed near the discharge port, there is no trouble due to wear, but the solvent is slightly inferior in terms of the cleaning effect because the force to remove the deposit is small. The contact with the coating solution at the outlet outlet changes the coating solution (solvent shock), induces coating defects such as pigment aggregation, and degrades the quality of the coated product.
[0013]
The present invention has been made based on the above-mentioned circumstances, and its purpose is to prevent the cleaning tool and the slit die from being worn, and the influence of the coating liquid on the coated product without adversely affecting the coated material. Application head cleaning method and cleaning apparatus capable of realizing cleaning and further forming high-quality coating film with high productivity, and manufacturing method of color filter using these cleaning method and cleaning apparatus, and It is to provide a manufacturing apparatus.
[0014]
[Means for Solving the Problems]
The object of the present invention is achieved by the means described below.
The method for cleaning a coating head according to claim 1 is a method for cleaning the periphery of the discharge port of the coating head that discharges the coating liquid from the discharge port, wherein the solvent discharge means and the gas discharge means are arranged in the longitudinal direction of the coating head. Placed side by side, While injecting gas from the gas discharge means, Dissolves the solvent that dissolves the coating solution from the solvent discharge means. After starting, the gas discharge means and the solvent discharge means are moved in the longitudinal direction of the coating head, and the solvent for dissolving the coating solution is removed. It was made to contact the deposit | attachment adhering to the discharge outlet periphery of the said coating head. straight Later, the deposits and solvent remaining in the periphery of the discharge port of the coating head are removed by collision with the gas ejected from the gas discharge means, and the removed deposits, the solvent and the gas are collected, Further, the collision position between the solvent and the deposit and the collision position between the deposit and the solvent and the gas remaining around the discharge port of the coating head are moved in the longitudinal direction of the coating head. Become.
[0018]
Claim 2 In the color filter manufacturing method according to the present invention, since the color filter is manufactured using the coating head cleaning method as described above, a high-quality color filter can be manufactured.
[0021]
The cleaning device for a coating head according to claim 3 is a cleaning device for a coating head for cleaning a peripheral portion of the discharge port of the coating head that discharges the coating solution from the discharge port, and the solvent for dissolving the coating solution is used as the cleaning device. Solvent discharge means for contacting deposits around the discharge port of the coating head, and deposits and solvent remaining around the discharge port of the coating head after collision with the deposit are removed by collision with gas. A gas discharge means, a removed deposit, a solvent, and a recovery means for recovering the gas; and the solvent discharge means and the gas discharge means are arranged in the longitudinal direction of the coating head, and all the means Is movable in the longitudinal direction of the coating head And further includes an operation control means for controlling the operation of moving the gas discharge means and the solvent discharge means in the longitudinal direction of the coating head. It consists of what is characterized by this.
[0022]
Claim 4 In the color filter manufacturing apparatus according to the above, since the color filter is manufactured using the above-described coating head cleaning apparatus, a high quality color filter can be manufactured.
[0023]
A method of cleaning a coating head according to claim 1 and claim 3 According to the coating head cleaning apparatus according to the present invention, the peripheral portion of the discharge port can be cleaned in a non-contact manner without contacting a cleaning tool to the peripheral portion of the discharge port of the slit die, and the coating liquid at the outlet of the slit die Deterioration of the coating solution due to contact with the solvent can be prevented by minimizing the contact time between the two.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1 is an overall schematic perspective view of a cleaning apparatus according to the present invention, FIG. 2 is a configuration diagram around a stage 6 and a slit die 40 in FIG. 1, and FIG. 3 is a front sectional view showing an embodiment of the cleaning apparatus according to the present invention. 4, 4, and 5 are side cross-sectional views of respective portions of FIG. 3.
[0025]
FIG. 1 shows a coating apparatus, that is, a so-called die coater 1 that is applied to manufacture of a color filter for a color liquid crystal display according to the present invention. The die coater 1 includes a base 2. A pair of guide groove rails 4 is provided on the base 2, and a stage 6 as a holding body is disposed on the guide groove rails 4 via a pair of slide legs 9. The upper surface 10 of the stage 6 is long with respect to the traveling direction, and is configured as a suction surface to which the substrate A that is a member to be coated can be fixed by vacuum suction. The stage 6 can reciprocate in the horizontal direction on the guide groove rail 4.
[0026]
Between the pair of guide groove rails 4, feed screw mechanisms 14, 16, and 18 shown in FIG. 2 and a casing 12 containing the mechanism are arranged, and the casing 12 extends in the horizontal direction along the guide groove rails 4. ing. As shown in FIG. 2, the feed screw mechanism has a feed screw 14 formed of a ball screw, and the feed screw 14 is screwed into a nut-like connector 16 fixed to the lower surface of the stage 6. The connector 16 extends through the both ends of the connector 16 and is rotatably supported by a bearing (not shown). An AC servomotor 18 is connected to one end of the connector 16. In addition, although the opening which accept | permits the movement of the connector 16 is formed in the upper surface of the casing 12, the opening is abbreviate | omitted in FIG.
[0027]
As shown in FIG. 1, an inverted L-shaped die support 24 is disposed on the upper surface of the base 2 at substantially the center thereof. The tip of the die support 24 is positioned above the reciprocating path of the stage 6, and an elevating mechanism 26 is attached to the tip. The elevating mechanism 26 includes an elevating bracket (not shown) that can be raised and lowered, and the elevating bracket is attached to a pair of guide rods in the casing 28 so as to be raised and lowered. A feed screw (not shown) made of a ball screw is also rotatably arranged in the casing 28 between guide lots, and a lifting bracket is connected to the feed screw via a nut-type connector. Yes. An AC servomotor 30 is connected to the upper end of the feed screw, and this AC servomotor 30 is attached to the upper surface of the casing 28.
[0028]
A die holder 32 is attached to the elevating bracket via a support shaft (not shown). The die holder 32 has a U-shape, and the upper part of the pair of guide groove rails 4 extends horizontally between them. It extends. Since the die holder 32 is rotatably supported in the elevating bracket by the support shaft, the die holder 32 is rotatable in the vertical plane.
[0029]
A horizontal bar 36 is also fixed to the lifting bracket. The horizontal bar 36 is located above the die holder 32 and extends along the die holder 32. Electromagnetically operated linear actuators 38 are respectively attached to both ends of the horizontal bar 36. These linear actuators 38 have telescopic rods protruding from the lower surface of the horizontal bar 36, and the lower ends of the telescopic rods are in contact with both ends of the die holder 32.
[0030]
A slit die 40 as a coating head is held in the die holder 32, and as is clear from FIG. 1, the slit die 40 is horizontal in the direction orthogonal to the reciprocating direction of the stage 6, that is, in the longitudinal direction of the die holder 32. And is supported by the die holder 32 at both ends thereof.
[0031]
As shown in FIG. 2, a coating solution supply hose 42 extends from the slit die 40, and the tip of the supply hose 42 is connected to a supply port of an electromagnetic switching valve 46 in the syringe pump 44. Yes. A suction hose 48 extends from the suction port of the electromagnetic switching valve 46, and the tip of the suction hose 48 is inserted into a tank 50 in which the coating liquid 70 is stored.
[0032]
The application liquid in the syringe 80 of the syringe pump 44 can be selectively connected to one of the supply hose 42 and the suction hose 48 by the switching operation of the electromagnetic switching valve 46. The piston 52 can be reciprocated in the vertical direction by a drive source (not shown), and in combination with the electromagnetic switching valve 46, the application liquid in the syringe 80 is supplied to the slit die 40 or in the tank 50. The coating liquid 70 can be filled into the syringe 80. The electromagnetic switching valve 46 and the drive source (not shown) of the piston 52 are electrically connected to a computer 54, and their operation is controlled in response to a control signal from the computer 54.
[0033]
In addition, a sequencer 56 is also electrically connected to the computer 54 to control the operation of the syringe pump 44. The sequencer 56 performs sequence control of the operation of the AC servo motor 18 that drives the feed screw 14 on the stage 6 side, the AC servo motor 30 on the lifting mechanism 26 side, and the linear actuator 38. Therefore, the sequencer 56 includes a signal indicating the operating state of the AC servomotors 18 and 30, a signal from the position sensor 58 that detects the moving position of the stage 6, and a sensor (not shown) that detects the operating state of the slit die 40. ) Is input. On the other hand, the sequencer 56 outputs a signal indicating a sequence operation to the computer 54.
[0034]
Next, as schematically shown in FIG. 2, the slit die 40 has a front lip 59 and a rear lip 60 which are blocks that are long in the width direction, ie, in a direction perpendicular to the reciprocating direction of the stage 6. Yes. The lips 59 and 60 face each other in the reciprocating direction of the stage 6 and are integrally connected to each other by a plurality of connecting bolts (not shown). Due to the coupling of both lips 59, 60, the lower portion of the slit die 40 has a sloped surface 66, 68 and forms a tapered shape, and the lowermost surface is formed as a discharge portion for the coating liquid.
[0035]
A manifold 62 is formed in the slit die 40 at the central portion thereof, and the manifold 62 extends horizontally in the width direction of the slit die 40. The manifold 62 is always connected to the above-described application liquid supply hose 42 via an internal passage (not shown), whereby the manifold 62 can be supplied with the application liquid.
[0036]
A slit 64 whose upper end communicates with the manifold 62 is formed inside the slit die 40, and the lower end of the slit 64 opens at the lower surface 74 of the slit die 40 to form the discharge port 72 of the slit die 40. Has been. The slit 64 is secured by a shim (not shown) sandwiched between the front lip 59 and the rear lip 60.
[0037]
Referring again to FIG. 1, the sensor column 20 is disposed on the upper surface of the base 2 in front of the die support 24. The sensor column 20 also has an inverted L-shape similar to the die column 24 described above, and holds the thickness sensor 22 via the bracket 21 so that the tip thereof is positioned above the reciprocating path of the stage 6.
[0038]
When the substrate A is placed on the stage 6, the thickness sensor 22 optically detects the thickness, and outputs a detection signal corresponding to the thickness to the computer 54.
A pair of left and right sensors 76 that measure the distance between the suction surface of the stage and the lower surface 74 of the slit die 40 are provided at the tip of the stage 6.
[0039]
With further reference to FIG. 1, a cleaning device 100 is provided on the base 2 between the sensor column 20 and the die column 24. The main body 102 of the cleaning device 100 extends in the longitudinal direction (width direction) of the slit die 40, that is, the direction orthogonal to the reciprocating direction of the stage 6. A rectangular carrier 106 is slidably attached to the main body 102 with the guide port 110 as a straight guide portion. Further, the lower portion of the carrier 106 is penetrated by a ball screw (not shown). The ball screw extends along the sliding direction of the carrier 106, and one end thereof is connected to the output shaft of the electric motor 104.
[0040]
Further, a flat bar 112 is attached to the carrier 106 via four lifting guides 108. A driving source such as an air cylinder (not shown) is connected to the flat bar 112 and can move freely in the vertical direction. A cleaning unit 120 is attached to the tip of the flat bar 112 so as to provide a certain clearance with the slit die 40. The cleaning unit 120 can move in the longitudinal direction of the slit die 40 by the operation of the carrier 106 and can be opposed to the lower surface 74 of the slit die 40 over the entire length. The operation of the cleaning unit 120 is controlled by the sequencer 56 shown in FIG.
[0041]
One embodiment of the cleaning unit 120 is a cleaning unit A130 shown in FIGS. The cleaning unit A 130 includes a solvent discharge / recovery unit 140 and an air injection / recovery unit 160.
[0042]
The solvent discharge / recovery unit 140 has a solvent 152 discharged from a pair of solvent nozzles 142A, 142 and solvent nozzles 142A, 142B whose discharge ports are directed horizontally with respect to the inclined surfaces 66, 68 of the slit die 40. Is made up of a coating liquid / solvent recovery box 144 that collides with the coating liquid 150 adhering to the lower surface 74 of the slit die 40 and collects the fallen matter 154. The coating liquid / solvent collection box 144 is connected to a suction source (not shown) through the connection port 146, and the inside 156 of the coating liquid / solvent collection box 144 is set to a negative pressure to collect the falling object 154 without taking it outside. Can do. The solvent nozzles 142A and 142B are also connected to a solvent supply source (not shown).
[0043]
The air injection / recovery unit 160 also includes a pair of air nozzles 162A, B and air nozzles 162A, B whose air discharge ports are directed horizontally with respect to the inclined surfaces 66, 68 of the slit die 40. From the liquid recovery box 165 for recovering the liquid fallen matter 178 generated by the jetted air 174 colliding with the liquid deposit 176 adhering to the lower surface 74 of the slit die 40 and the air recovery box 164 for recovering the air 174 It is configured. The liquid recovery box 165 and the air recovery box 164 have connection ports 172 and 170, respectively, and are connected to separate suction sources (not shown) to connect the interior 166 of the liquid recovery box 165 and the interior 168 of the air recovery box 164, respectively. It is possible to reliably recover the liquid fallen matter 178 and the air 174 without leaking to the outside by using a negative pressure. Air nozzles 162A and B are also connected to an air supply source (not shown).
[0044]
The cleaning method using this cleaning unit A130 is performed as follows.
First, the electric motor 104 of the cleaning device 100 is driven to move the flat bar 112, and the cleaning unit A 130 placed on the flat bar 112 is moved to the longitudinal end portion (either side) of the slit die 40. Stop. Subsequently, a suction source (not shown) is started to make the inside 156 of the coating liquid / solvent recovery box 144 have a negative pressure, and the solvent is discharged from the solvent nozzles 142A and 142B, so that the cleaning unit A130 is connected to the slit die 40. It moves toward the opposite end, and the coating solution 150 and other things adhering to the lower surface 74 and the slopes 66 and 68 of the slit die 40 are washed away and collected in the coating solution / solvent collection box 144 together with the solvent ( Solvent washing step).
[0045]
When it reaches the opposite end of the slit die 40, it stops, and the solvent discharge from the solvent nozzles 142A, 142B also stops. Subsequently, air is ejected from the air nozzles 162A and 162B, and another suction source (not shown) is started and suction is performed from the connection ports 172 and 170, so that the inside 168 of the air collection box 164 and the inside 168 of the liquid collection box 165 are obtained. And negative pressure. In this state, the cleaning unit A130 is moved to the first end portion of the slit die 40, and the liquid deposits 176 such as a solvent remaining on the lower surface 74 and the inclined surfaces 66 and 68 of the slit die 40 are blown off to be ejected. The recovered air is recovered from the liquid recovery box 165 and the air recovery box 164 (residual solvent recovery step). At this time, when the air is directly sprayed on the remaining solvent or the like, the solvent or the like is sprayed and reattached to the lower surface 74 or the like of the slit die 40. It is important to adjust the position of the air nozzles 162A and 162B so that air is jetted onto the surface to create an air flow that flows in the longitudinal direction of the slit die 40, thereby blowing off the solvent and the like.
[0046]
Further, by shortening the time from the solvent washing step to the residual solvent recovery step, the contact time of the solvent with the coating solution at the outlet of the discharge port 72 of the slit die 40 is shortened, and the time margin for alteration of the coating solution is obtained. Is preferably not given.
[0047]
The solvent used in each of the above steps is preferably a solvent constituting the coating liquid. This is because even if the coating liquid is dried and becomes a solid film and adheres to the periphery of the discharge port portion of the slit die 40, it can be washed away by the dissolving action.
[0048]
In the above example, both the solvent washing step and the residual solvent recovery step are performed once. However, the cleaning step and the residual solvent recovery step may be performed a plurality of times until they can be completely cleaned. The step may be repeated many times.
[0049]
Next, a coating method using the above coating head cleaning method will be described.
First, when the origin of each operating unit in the coating apparatus is returned, the stage 6 and the slit die 40 are moved to the standby position. At this time, the coating liquid has already been filled from the tank 50 to the slit die 40, and the so-called air bleeding operation of discharging the coating liquid with the slit die 40 facing upward to discharge the residual air inside has already been completed. Yes. Then, lift pins (not shown) rise on the surface of the stage 6. When the substrate A is placed on the loader (not shown) on the stage 6, the lift pins are lowered to place the substrate A on the upper surface 10 of the stage 6. To adsorb.
[0050]
Subsequently, the cleaning device 100 using the cleaning unit A 130 as the cleaning unit 120 is operated, and the lower surface 74 and the slopes 66 and 68 of the slit die 40 are cleaned cleanly by the cleaning method described above. When the cleaning operation is completed, the stage 6 is driven to move the application start portion of the substrate A to a position just below the discharge port 72 of the slit die 40 and stop it. In this stop state, the thickness sensor 22 measures the substrate thickness of the substrate A, and based on the thickness, the slit die 40 is adjusted so that the clearance between the substrate A and the lower surface 74 of the slit die 40 becomes a predetermined value. Descend.
[0051]
On the other hand, the syringe pump 44 sucks a predetermined amount of the coating liquid 70 from the tank 50 during this time, and after the clearance setting is confirmed, the coating liquid 70 is sent from the syringe pump 44 to the slit die 40. Simultaneously with the start of the feeding operation of the syringe pump 44, a timer in the computer 54 starts, and after a predetermined time for forming the coating liquid bead C between the lower surface 74 of the slit die 40 and the substrate A, the computer 54 A start signal is issued to the sequencer 56, the stage 6 starts moving at the coating speed, and coating is started.
[0052]
When the application end position of the substrate A comes directly below the discharge port 72 of the slit die 40, a stop command is issued from the computer 54 to the syringe pump 44 to stop the discharge of the coating liquid from the slit die 40, and the slit die 40 To completely reach the coating liquid bead C.
[0053]
During these operations, the stage 6 continues to move, stops when the substrate A reaches the end point position, releases the suction of the substrate A, raises the lift pins, and lifts the substrate A. At this time, the substrate A is transferred to the next step by an unloader (not shown). Thereafter, the stage 6 lowers the lift pins and returns to the original position. At the same time, the syringe pump 44 performs a suction operation to newly fill the coating liquid 70 from the tank 50. Then, waiting for the next substrate A to come, the same operation is repeated. Among the above coating methods, when the coating is completed, the coating liquid remains attached around the discharge port 72 of the slit die 40. This remaining coating solution is removed by the cleaning device 100 before the start of the next coating according to the coating cycle described above. However, when the coating liquid is easy to evaporate and is immediately dried, the remaining coating liquid is removed by the cleaning device 100 immediately after the coating is finished, and the peripheral portion of the discharge port 72 of the slit die 40 is removed. It is desirable to clean.
[0054]
Next, with reference to FIGS. 6-9, the cleaning unit B200 which is another example of embodiment of this invention is demonstrated. 6 is a front sectional view of the cleaning unit B200, FIGS. 7 and 8 are side sectional views at different positions in FIG. 6, and FIG. 9 shows a cleaning process by the cleaning unit B200.
[0055]
First, referring to FIGS. 6 to 8, the cleaning unit B200 includes a pair of air nozzles 208A whose air discharge ports are directed horizontally with respect to the inclined surfaces 66 and 68 of the slit die 40 for jetting air 222. , B and a lower nozzle 212 directed to the lower surface 74 of the slit die 40. Further, on the opposite side of these nozzles, a pair of air nozzles 206A and 206B, in which the discharge ports are directed horizontally with respect to the inclined surfaces 66 and 68 of the slit die 40 for the air 222 injection, A lower solvent nozzle 210 that discharges the solvent 224 toward the lower surface 74 is provided. The air nozzles 206A, B, 208A, B and the lower solvent nozzle 210 are connected to an air supply source and a solvent supply source (not shown), respectively.
[0056]
Each of the nozzles described above is held by the main body 202 that is also an air suction / collection port. By fixing the main body 202 on the flat bar 112, the slit die 40 can be moved in the longitudinal direction. Both ends of the main body 202 in the longitudinal direction of the slit die 40 have a shape similar to the tip of the discharge port of the slit die 40 and are arranged with a certain gap. Further, the central portion of the main body 202 is provided with an internal space 216 so that air ejected from each air nozzle can be collected. Since the internal space 216 communicates with the connection port 220, connecting the internal space 216 to a suction source (not shown) makes the internal space 216 a negative pressure and prevents the air injected from each nozzle from leaking to the outside. Can do.
[0057]
A liquid recovery port 204 is also disposed at the center of the internal space 216. The liquid recovery port 204 communicates with a suction source (not shown) through the connection port 218, and the internal 214 can be made to have a negative pressure by a suction action so that a liquid such as a solvent can be recovered without leaking to the outside.
[0058]
A cleaning method using the above cleaning unit B200 will be described with reference to FIG. FIG. 9 is a schematic view showing a cleaning process.
[0059]
First, the cleaning unit B 200 is attached to the flat bar 112 as the cleaning unit 120 of the cleaning apparatus 100. Next, the electric motor 104 is driven to move the flat bar 112, and the cleaning unit B200 is moved to the left end of the slit die 40 shown in FIG. 9 and stopped (step a in FIG. 9). .
[0060]
Then, a suction source (not shown) is started to make the inside 214 of the liquid recovery port 204 and the internal space 216 of the main body 202 have a negative pressure, and air injection is started from the air nozzles 206A and 206B. In this state, the cleaning unit B200 is moved toward the opposite end (right end in FIG. 9) of the slit die 40, and the coating liquid adhering to the lower surface 74 and the inclined surfaces 66, 68 of the slit die 40, Others are blown off by air injection, and the fallen object 214 made of the blown-off coating liquid is recovered at the liquid recovery port 204 (step b in FIG. 9) and stops when it reaches the opposite end of the slit die 40. . Through the above steps, the coating liquid is substantially removed from the periphery of the discharge port 72 of the slit die 40, and a little dried coating liquid remains later.
[0061]
When the cleaning unit B200 reaches the opposite end of the slit die 40, the air injection from the air nozzles 206A and 206B is stopped, and instead, the air injection from the air nozzles 208A and B and the lower nozzle 212 is started. At the same time, the discharge of the solvent from the lower solvent nozzle 210 is also started (step c in FIG. 9). The solvent is discharged from the lower solvent nozzle 210 at a discharge speed at which the discharged solvent reaches not only the lower surface 74 of the slit die 40 but also the inclined surfaces 66 and 68. In this state, the cleaning unit B200 is moved toward the end portion (left end portion in FIG. 9) where the slit die 40 is located. By this operation, the solvent 224 is attached to the lower surface 74 and the inclined surfaces 66 and 68 of the slit die 40, and the film of the coating solution adhering to the surface is dissolved and peeled off from the lower surface 74 and the inclined surfaces 66 and 68. The air jetted from the air nozzles 208A and 208B and the lower nozzle 212 is blown off together with the solvent into a fallen object 232, which is collected in the liquid recovery port 204 and the main body 202 (step d in FIG. 9). .
[0062]
When the cleaning unit B200 reaches the end of the slit die 40 (the left end in FIG. 8), the cleaning unit B200 stops, air jets from the air nozzles 208A and B, the lower nozzle 212, and the solvent from the lower solvent nozzle 210. While stopping the discharge, the suction source (not shown) is also stopped, and the suction from the liquid recovery port 204 and the main body 202 is also stopped (step e in FIG. 9).
[0063]
Even in the above-described cleaning method, for the same reason as the cleaning method using the cleaning unit A130, air is sprayed on each surface of the dried slit die 40 to which no solvent or the like is adhered, and the longitudinal direction of the slit die 40 is It is important to adjust the position of each air nozzle so as to create a flowing air flow and thereby blow away solvent and the like.
Further, as a matter of course, the solvent 224 is preferably a solvent constituting the coating liquid.
[0064]
Further, in the above embodiment example, immediately after the solvent 224 is attached to the lower surface 74 and the inclined surfaces 66 and 68 of the slit die 40, the solvent and the like are removed by air injection. The contact time with the coating liquid at the outlet of the coating liquid is short, and it is possible to prevent the coating liquid from being altered.
[0065]
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 500 cps, and Newtonian is preferable from the viewpoint of coating properties, but it can also be applied to coating liquids having thixotropy. Further, the present invention is not particularly dependent on the drying speed of the coating liquid, and the present invention can be applied to slit die cleaning means when coating with a die coater on resist and O / C materials in addition to the RGB color coating liquid. As a member to be coated which is a substrate, a metal plate such as aluminum, a ceramic plate, a silicon wafer or the like may be used in addition to glass. Further, as a coating state to be used, the clearance is 40 to 500 μm, more preferably 80 to 300 μm, the coating speed is 0.1 m / min to 10 m / min, more preferably 0.5 m / min to 6 m / min, the die lip The gap 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.
[0066]
Moreover, as conditions for cleaning, the discharge speed of the air injected from each nozzle is 1 to 300 m / s, preferably 10 to 100 m / s. The shape of the air discharge part and the solvent discharge part of the air nozzle and the solvent discharge nozzle may be round, slit-shaped rectangular or any other shape. In the case of a round shape, the inner diameter of the discharge part is 0.1 to 10 mm, preferably 0.5 to 5 mm, and in the case of a rectangle, the gap is 0.05 to 5 mm, more preferably 0.1 to 5 mm.
[0067]
The amount of solvent discharged is preferably as small as possible, preferably 0.1 cc / s to 50 cc / s, more preferably 0.5 cc / s to 10 cc / s.
[0068]
Moreover, the part made into a negative pressure for collection | recovery of a solvent, a coating liquid, and air is 10 Pa-50 kPa, Preferably it is 100 Pa-10 kPa. The length of the liquid or solvent recovery port in the substrate running direction is preferably slightly larger than the lower surface 74 of the slit die 40.
[0069]
Furthermore, although it is an installation angle of each nozzle and a slit die, it is 20 to 90 degrees on the small side for both air and solvent, and more preferably 45 to 75 degrees.
[0070]
Moreover, the moving speed of the cleaning unit is preferably 0.1 to 50 m / min, more preferably 0.5 to 15 m / min.
[0071]
【Example】
On a non-alkali glass substrate having a thickness of 360 × 465 mm and a thickness of 0.7 mm, the pitch is 254 μm in the substrate width direction, the pitch is 85 μm in the longitudinal direction of the substrate, the line width is 20 μm, and the number of RGB pixels is 4800 (substrate longitudinal direction). A black matrix film having a lattice shape of × 1200 (substrate width direction) and a diagonal length of 20 inches (305 mm in the substrate width direction and 406 mm in the substrate longitudinal direction) and a thickness of 1 μm was formed. The black matrix film was obtained using titanium oxynitride as a light shielding material and polyamic acid as a binder.
[0072]
Subsequently, after removing particles on the substrate by wet cleaning, polyamic acid as a binder, γ-butyrolactone, a mixture of N-methyl-2-pyrrolidone and 3-methyl-3-methoxybutanol as a solvent, and Pigment Red 177 as a pigment. An R-color coating solution, which was mixed at a solid content concentration of 10% and further adjusted to a viscosity of 50 cps, was uniformly coated with a die coater shown in FIG. 1 at a speed of 3 m / min at a thickness of 20 μm. Here, the slit die of the die coater had a slit gap of 100 μm, a slit width of 305 mm, and a gap (clearance) between the slit die and the substrate of 100 μm. At this time, a cleaning unit B shown in FIG. 6 was used as the slit die discharge port cleaning means, and the periphery of the slit die discharge port was surely cleaned before coating. Here, each air nozzle has a concentric cross section and an inner diameter of 1 mm, a lower solvent nozzle to which the solvent is attached has a concentric cross section and an inner diameter of 1.5 mm, and a liquid recovery port is 30 mm (slit The longitudinal direction of the die was 10 mm (substrate running direction), and the recovery part of the main body was a rectangular shape of 60 mm (slit die longitudinal direction) × 20 mm (substrate running direction). Each operating condition is that air is discharged from each air nozzle at a discharge air velocity of 20 m / s, γ-butyrolactone is discharged from a lower solvent nozzle at a discharge speed of 0.5 m / s, the liquid recovery port is 2 kPa, and the main body is recovered. The part was sucked so as to have a negative pressure of 1 kPa. Furthermore, the moving speed of the cleaning unit B in the longitudinal direction of the slit die was 10 m / min.
[0073]
After coating, after drying at 100 ° C. for 20 minutes with a drying apparatus using a hot plate, apply 10 μm of a resist solution having a solid content concentration of 10% and a viscosity of 8%, and after drying for 10 minutes on a 90 ° C. hot plate, exposure and development -Peeling was performed, leaving a color coating film only on the R pixel portion, and curing was performed by heating for 30 minutes on a 260 degree hot plate.
[0074]
For the G and B colors, the same color coating is applied to the G and B colors using the same process as the R coater, the die coater and the above cleaning means, and the coating conditions and cleaning conditions. Formed. Here, the G color coating solution is an R color coating solution in which the pigment is Pigment Green 36 and the viscosity is adjusted to 40 cps at a solid content concentration of 10%. The B color coating solution is an R color coating solution. The pigment was Pigment Blue 15 and the viscosity was adjusted to 50 cps with a solid content concentration of 10%.
[0075]
Finally, ITO was deposited by sputtering to create a color filter. The obtained color filter had no foreign matter such as pigment agglomerates and abrasion powder, and the chromaticity was uniform over the entire surface of the substrate, which was satisfactory in terms of quality.
[0076]
【The invention's effect】
As described above, the coating head cleaning method and the cleaning apparatus according to the present invention employ the excellent method and apparatus configuration as described above, so that there is no adverse effect on the coated object due to wear of the cleaning tool and slit die, and alteration of the coating liquid. In addition, it is possible to clean the peripheral portion of the discharge port of the slit die, and to form a high-quality coating film with high productivity by the cleaning method and the coating method and coating device using the cleaning device.
[0077]
Furthermore, according to the color filter manufacturing method and manufacturing apparatus of the present invention, since the color filter is manufactured using the above-described excellent coating head cleaning method and cleaning device, the quality is high without any defects due to cleaning. A color filter can be manufactured with high productivity.
[Brief description of the drawings]
FIG. 1 is an overall schematic perspective view of a die coater according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram illustrating the die coater of FIG. 1 including a coating liquid supply system.
FIG. 3 is a front sectional view showing a cleaning device according to an embodiment of the present invention.
4 is a side sectional view taken along line XX of FIG.
5 is a side sectional view taken along line YY in FIG. 3;
FIG. 6 is a front sectional view showing a cleaning device according to another embodiment of the present invention.
7 is a side sectional view taken along line XX in FIG. 6;
8 is a side cross-sectional view taken along line YY in FIG.
FIG. 9 is a schematic view showing a cleaning process.
[Explanation of symbols]
1 Die coater
2 base
6 stages
14 Feed screw
22 Thickness sensor
40 Slit die (coating head)
44 Syringe pump
50 tanks
62 Manifold
64 slits
66, 68 slope
72 Discharge port
74 Bottom
100 Cleaning device
102 body
104 Electric motor
106 Career
108 Lifting guide
110 Guide mouth
112 Flat bar
120 Cleaning unit
130 Cleaning unit A
140 Solvent discharge / recovery unit
142A, 142B Solvent nozzle
144 Coating liquid / solvent recovery box
160 Air injection / recovery unit
162A, 162B Air nozzle
164 Air recovery box
165 Liquid recovery box
174 air
178 Falling liquid
200 Cleaning unit B
202 body
204 Liquid recovery port
206A, 206B Air nozzle
208A, 208B Air nozzle
210 Lower solvent nozzle
212 Lower nozzle
A substrate

Claims (4)

This is a method for cleaning the periphery of the discharge head of the coating head that discharges the coating liquid from the discharge port. The solvent discharge means and the gas discharge means are arranged in the longitudinal direction of the coating head, and the gas is ejected from the gas discharge means. And starting the discharge of the solvent for dissolving the coating liquid from the solvent discharge means, and then moving the gas discharge means and the solvent discharge means in the longitudinal direction of the coating head, so that the solvent for dissolving the coating liquid is removed from the coating head. after brought into contact with the deposits adhering to the peripheral discharge opening directly into the deposits and the solvent remaining in the discharge port peripheral portion of the coating head, thereby removing the collision of the gas injected from the gas ejection means The removed deposit, the solvent and the gas are recovered, and the collision position between the solvent and the deposit, and the collision position between the deposit, the solvent and the gas remaining around the discharge port of the coating head, Wherein the moving in the longitudinal direction of the fabric head cleaning method of the coating head.    A method for producing a color filter, comprising producing a color filter by using the coating head cleaning method according to claim 1. A cleaning device for a coating head for cleaning a peripheral portion of a discharge head of a coating head that discharges a coating solution from a discharge port, wherein a solvent that dissolves the coating solution is attached to the periphery of the discharge port of the coating head. Solvent discharge means for contacting the kimono, gas discharge means for removing the deposit and solvent remaining around the discharge port of the coating head after collision with the deposit by collision with gas, and the deposit and solvent removed has a recovery means for recovering the gas and further the solvent discharge means and the gas discharging means with being arranged in the longitudinal direction of the coating head, Ri is all means movably der in the longitudinal direction of the coating head An application head cleaning apparatus , further comprising operation control means for controlling an operation of moving the gas discharge means and the solvent discharge means in the longitudinal direction of the application head.    A color filter manufacturing apparatus that manufactures a color filter using the coating head cleaning apparatus according to claim 3.

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