JP4218376B2 - Coating method and manufacturing method of display member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used, for example, in the field of manufacturing color filters for color liquid crystal displays and array substrates, optical filters, printed circuit boards, integrated circuits, semiconductors, and the like. How to form a coating film while discharging Law, In addition, the present invention relates to an improvement in a method for manufacturing a display member using these coating methods.
[0002]
[Prior art]
A color liquid crystal display is composed of an array substrate, a color filter, and the like, and both the array substrate and the color filter include many manufacturing processes in which a low-viscosity liquid material is applied and dried to form a coating film. For example, in a color filter having a fine lattice pattern of three primary colors on a glass substrate, black, red, blue and green coating liquids are sequentially coated on the glass substrate to form the coating film. . In addition, after applying a photoresist material to form a coating film, pattern processing is performed by photolithography to form a column for forming a liquid crystal space injected between the color filter and the array substrate. For example, an overcoat coating film for forming a fine film may be formed. In this type of coating formation process, spinners have been used in many cases because the viscosity of the coating solution used is several tens of mPaS or less, and a uniform coating can be easily formed. Thus, a combination of reducing the consumption of expensive coating liquid and the difficulty in increasing the size of the apparatus accompanying the increase in the size of the substrate to be coated has led to the introduction of many die coaters.
[0003]
As an example of this type of die coater, a reciprocable table and a coating head having a downward discharge port are provided, and after the glass substrate is sucked and held on the table, the glass substrate and the table are coated with the coating head. When moving underneath, a coating liquid is discharged from the discharge port of the coating head, and a coating film is continuously formed on a glass substrate (for example, Patent Document 1).
[0004]
In addition, since coating is performed on each substrate, the coating method at the start and end of coating is important for improving the film thickness accuracy of the entire substrate. (For example, Patent Document 2), a bead is formed between a die and a roll by preliminarily applying from a die to a roll, and then the die is moved toward the substrate together with the bead to the substrate. (For example, patent document 3) etc. which start this application | coating. Furthermore, in order to prevent the coating start portion from becoming thicker, some clearances are controlled in conjunction with the discharge of the coating liquid and the horizontal movement of the die with respect to the substrate (for example, to prevent the thickening of the coating start portion (for example, Patent Document 4).
[0005]
[Patent Document 1]
JP-A-6-339656 (5th column 18th line to 7th column 25th line, 10th column 9th line to 43rd line, FIG. 1)
[0006]
[Patent Document 2]
JP-A-8-229482 (column 13, line 46 to column 15, line 48, FIG. 3)
[0007]
[Patent Document 3]
JP 2001-310147 A (first column 5th line to 50th line, second column 43th line to 50th line, fourth column 9th line to fifth column 37th line, FIG. 1, FIG. 3, (Fig. 4)
[0008]
[Patent Document 4]
JP-A-2002-113411 (Claim 5, fourth column, 48th line to fifth column, 24th line, ninth column, third line to 31st line, FIGS. 1 and 5)
[0009]
[Problems to be solved by the invention]
Among the above-mentioned application starting means, those that preliminarily apply from the die to the roll and then start the main application to the substrate are 1) extra equipment is required and expensive, and 2) extra operation. Therefore, the tact time becomes long and the productivity is hindered. 3) A small amount of coating liquid remains at the tip of the die discharge port after preliminary application to the roll, but this residual amount is not constant and the coating start portion The film thickness fluctuates and is not stable. 4) Since the amount of the invalid coating solution that is not necessary for the original coating increases due to the preliminary coating, there is a problem that the cost is increased.
[0010]
[Means for Solving the Problems]
On the other hand, when a coating solution using a highly volatile solvent is applied with a wet thickness of 20 μm or less using a coating method without pre-coating, as shown in FIG. It can occur anywhere in any direction. 1) Clean the area around the discharge port of the die before coating in order to keep the state of the coating start part always the same. At this time, the coating liquid inside the die near the discharge port is held and a gap is generated. 2) After cleaning around the discharge port of the die, the solvent of the coating liquid around the discharge port evaporated in a short time until application, and a gap was generated inside the die near the discharge port according to the evaporation amount. For this reason, it is presumed that there is a gap that is not filled with the coating liquid inside the die, and this is transferred as it is to the coating start portion of the substrate, resulting in an uncoated portion. This phenomenon is very difficult to occur when the wet coating thickness exceeds 20 μm, but this is considered to have no effect since the ratio of the void amount to the discharge amount of the coating liquid becomes small. On the other hand, when pre-coating is performed, the gap near the discharge port is pushed out, so that the coating can be performed without any gap inside the die, so that there is no problem that a part that is not applied is generated at the coating start part. .
[0011]
The present invention has been made on the basis of the above-mentioned circumstances, and its object is to provide high quality and film thickness over the entire surface of the substrate without performing preliminary coating for any kind of coating liquid and coating thickness. A coating method that can easily achieve uniform coating, reducing the tact time, and reducing the amount of ineffective use of coating solution. Nobukata Law and this It is providing the manufacturing method of the member for a display which uses a method.
[0012]
[Means for Solving the Problems]
The above object is achieved by the means described below.
[0014]
The present invention Coating In the cloth method, an applicator having a discharge port extending in one direction is brought close to a member to be coated, a coating liquid is supplied from the coating liquid supply means to the coating device, and the coating liquid is discharged from the discharge port of the coating device. In the coating method of forming a coating film on the member to be coated by moving either the container and the member to be coated in the horizontal direction, A second clearance larger than the first clearance after waiting for a fixed time after discharging a constant volume Q of the coating liquid from the applicator after the applicator is brought close to the stationary member to be coated by the first clearance; After moving the applicator, the coating liquid is discharged from the applicator to the coated member, and the relative movement of the coated member with respect to the coating device is started to form a coating film on the coated member. . Further, the constant volume Q of the coating liquid discharged from the discharge port of the applicator is such that the length in the application direction of the surface including the discharge port of the applicator is L, the length of the discharge port in the longitudinal direction of the applicator is W, and the constant volume Q It is also preferable that Q = α2 × S × L × W, 0.05 ≦ α2 ≦ 1.0, where S is the clearance between the applicator and the member to be coated when discharging the liquid.
[0016]
The display member manufacturing method of the present invention manufactures a display member using any one of the above coating methods.
[0017]
Application method according to the present invention The law If it is used, a minute amount of coating solution is discharged from the applicator and waits for a certain period of time before forming a coating film on the member to be coated. Since the void is discharged to the outside of the applicator and the void is eliminated by the coating liquid outside the discharge port, high-quality and uniform film thickness can be applied from the application start portion without performing preliminary discharge. . This coating method can be applied to any kind of coating solution and coating conditions.
[0018]
According to the method for manufacturing a display member according to the present invention, the display member is manufactured using the above-described excellent coating method. Therefore, a high-quality display member can be manufactured at low cost. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
[0020]
FIG. 1 relates to the present invention. Ru 2 is a schematic front cross-sectional view of the equator 1, FIG. 2 is a time line diagram showing the operation state of each operation unit when applying using the die coater 1, FIG. 3 is a plan view showing the application state on the substrate, and FIG. It is a schematic perspective view which shows the bead formation condition of the die | dye 20 and the board | substrate A. FIG.
[0021]
Referring to FIG. 1, a die coater 1 of the present invention is shown. The die coater 1 includes a base 2, and a pair of guide rails 4 are provided on the base 2. A stage 6 is disposed on the guide rail 4, and the stage 6 is driven by a linear motor (not shown) and freely reciprocates in the X direction shown in FIG. Further, the upper surface of the stage 6 is a vacuum suction surface made up of suction holes, and can hold the substrate A as a member to be coated by suction.
[0022]
Looking at the center of the base 2, there is a gate-shaped column 10. On both sides of the support column 10, an up-and-down lift unit 70 is provided, and a die 20 that performs coating is attached to the up-and-down lift unit 70.
[0023]
The die 20 has a front lip 22 and a rear lip 24 extending in a direction perpendicular to the X direction indicated by an arrow, that is, a direction perpendicular to the paper surface, overlapped in the X direction via a shim 32 and integrated by a plurality of connecting bolts (not shown). It is comprised by combining. A manifold 26 is formed at the center of the die 20, and this manifold 26 also extends in the longitudinal direction of the die 20 (direction orthogonal to the X direction). A slit 28 is formed below the manifold 26 so as to communicate therewith. The slit 28 also extends in the longitudinal direction of the die 20, and the lower end thereof becomes an opening at the discharge port surface 36 that is the lowest end surface of the die 20, thereby forming the discharge port 34. Since the slit 28 is formed by the shim 32, the slit gap (measured in the X direction) is equal to the thickness of the shim 32.
[0024]
The vertical lift unit 70 for lifting and lowering the die 20 includes a suspension holding base 80 that holds the die 20 in a suspended form, a pair of left and right lifting bases 78 that raise and lower the suspension holding base 80, and a lift base 78 in the vertical direction. It comprises a guide 74 for guiding and a ball screw 76 for converting the rotational motion of the motor 72 into the linear motion of the lifting platform 78. The vertical lift unit 70 has a pair of left and right so as to support both ends of the die 20 in the longitudinal direction, and each can be lifted and lowered independently, so that the tilt angle with respect to the horizontal in the longitudinal direction of the die 20 can be arbitrarily set. Thereby, the discharge port surface 36 of the die 20 and the substrate A can be made substantially parallel over the longitudinal direction of the die 20. Further, the vertical lift unit 70 can provide a clearance, that is, a clearance of any size between the substrate A on the stage 6 and the discharge port surface 36 of the die 20.
[0025]
Further, when the right end portion of the base 2 is viewed in FIG. 1, the wiping unit 90 is mounted on the guide rail 4 so as to be movable in the X direction. In the wiping unit 90, a wiping head 92 having a shape that engages with the periphery of the discharge port 34 of the die 20 is attached to the slider 96 via a bracket 94. The slider 96 is freely moved by the drive unit 98 in the longitudinal direction of the die 20, that is, in a direction orthogonal to the X direction. The drive unit 98 and the tray 100 are fixed on the carriage 102. Since the carriage 102 is on the guide rail 4 and is guided by the guide rail 4 and can freely reciprocate in the X direction by a linear motor (not shown), the entire wiping unit 90 can reciprocate in the X direction. When wiping is performed, the entire wiping unit 90 is moved in the X direction to a position where the wiping head 92 is engaged with the die 20, and the die 20 is lowered and engaged with the wiping head 92. When the driving unit 98 is driven to slide the wiping head 92 in the longitudinal direction of the die 20, the coating liquid and other contaminants remaining in the vicinity of the discharge port of the die 20 can be removed and cleaned. The removed coating liquid and the like are collected in the tray 100. The tray 100 is connected to a discharge line (not shown) and can discharge and collect a liquid such as a coating liquid accumulated inside. The tray 100 can also be used for collecting a coating solution discharged from the die 20 by air bleeding or the like. The wiping head 92 is preferably an elastic body such as rubber or a synthetic resin so that it can be engaged with the die 20 evenly.
[0026]
Further, when viewing the left side of the base 2, a thickness sensor 120 for measuring the thickness of the substrate A is attached to the support base 122. The thickness sensor 120 preferably uses a laser. By measuring the thickness of the substrate A with the thickness sensor 120, the clearance that is the gap between the discharge port surface 36 of the die 20 and the substrate A is always constant for the substrate A of any thickness. be able to.
[0027]
Looking again at the die 20, the upstream side of the manifold 26 of the die 20 is always connected to a supply hose 60 connected to the coating liquid supply device 40 via an internal passage (not shown). The coating liquid can be supplied from the coating liquid supply apparatus 40. The coating liquid that has entered the manifold 26 is uniformly widened in the longitudinal direction of the die 20 and is discharged from the discharge port 34 through the slit 28.
[0028]
The coating liquid supply device 40 includes a supply valve 42, a syringe pump 50, a suction valve 44, a suction hose 62, and a tank 64 on the upstream side of the supply hose 60. A coating liquid 66 is stored in the tank 64, and a back pressure of an arbitrary magnitude can be applied to the coating liquid 66 by being connected to a pressure air source 68. The coating liquid 66 in the tank 64 is supplied to the syringe pump 50 through the suction hose 62. In the syringe pump 50, a syringe 52 and a piston 54 are attached to a pump main body 56. Here, the piston 54 can reciprocate freely in the vertical direction by a drive source (not shown). The syringe pump 50 is a constant-capacity pump that fills a syringe 52 having a constant inner diameter with a coating liquid, pushes it out by a piston 54, and supplies the die 20 to a single substrate A by coating. When filling the syringe 52 with the coating liquid 66, the suction valve 44 is opened, the supply valve 42 is closed, and the piston 54 is moved downward. When supplying the coating liquid filled in the syringe 52 toward the die 20, the suction valve 44 is closed, the supply valve 42 is opened, and the piston 54 is moved upward so that the piston 54 moves inside the syringe 52. The coating liquid is pushed up and discharged. In order to provide airtightness between the male-side piston 54 and the female-side syringe 52, an O-ring (not shown) is preferably attached to the piston 54 as a sealant therebetween.
[0029]
Note that the linear motor, the motor 72, the coating liquid supply device 40, and the like that are operated by the control signal are all electrically connected to the control device 200. Then, a control command signal is transmitted to each device in accordance with an automatic operation program incorporated in the control device, and a predetermined operation is performed. When changing the conditions, if a change parameter is appropriately input to the operation panel 202, the change parameter is transmitted to the control device 200, and the change of the driving operation can be realized.
[0030]
Next, the present invention The first The coating method 1 will be described in detail.
[0031]
First, when the origin of each operation unit of the die coater 1 is returned, each moving unit moves to the standby position. That is, the stage 6 moves to the left end of FIG. 1 (a position indicated by a broken line), the die 20 moves to the top, and the wiping unit 90 moves so that the tray 100 is positioned below the die 20. Here, the coating liquid 66 is already filled from the tank 64 to the die 20, and the operation of discharging the residual air inside the die 20 has already been completed. At this time, the coating liquid supply device 40 is in a state where the syringe 52 is filled with the coating liquid 66, the suction valve 44 is closed, the supply valve 42 is opened, and the piston 54 is in the lowermost position. 20 can be supplied.
[0032]
First, lift pins (not shown) are raised on the surface of the stage 6, and the substrate A is placed on the lift pins from a loader (not shown). Next, the lift pins are lowered and the substrate A is placed on the upper surface of the table 6 and simultaneously held by suction. At the same time, the coating liquid supply device 40 is operated to discharge a small amount of the coating liquid 66 toward the tray 100, and then the wiping unit 90 is moved so that the wiping head 92 is positioned just below the discharge port 34 of the die 20. Let Then, the die 20 is lowered and the discharge port surface 36 of the die 20 is engaged with the wiping head 92, and then the wiping head is slid in the longitudinal direction of the die 20 so that the vicinity of the discharge port 34 of the die 20 extends in the longitudinal direction of the die 20 to clean up. After the cleaning is completed, the wiping unit 90 returns to the original place (the right end in FIG. 1).
[0033]
Then, the coating liquid supply device 40 is operated again, and a certain amount of coating liquid is discharged from the discharge port 34 of the die 20. Since the coating liquid discharged here is a minute amount, it does not fall downward, but remains in a form of hanging from the discharge port 34 and the discharge port surface 36 around it. At this time, if there is a minute gap near the discharge port 34 of the slit 28, the slit 28 is pushed out of the discharge port 34. Since the coating liquid discharged from the discharge port 34 flows along the longitudinal direction of the discharge port 34, even if there is a gap in the slit 28 and the coating liquid is not poured out, this longitudinal direction The void portion is eliminated by the coating liquid transmitted to, and the lower part of the discharge port 34 is filled with the coating liquid connected in the longitudinal direction. The amount of sag from the discharge port 34 of the coating liquid connected at the lower portion of the discharge port 34 is made uniform over the longitudinal direction of the die 20 by the action of surface tension. Here, the discharge amount from the discharge port 34 is as follows. Referring to FIG. 4, the surface including the discharge port 34 of the die, that is, the discharge direction of the discharge port surface 36 is L, and the length of the discharge port 34 in the longitudinal direction of the die 20 When the length is W and the clearance, which is the gap amount when the discharge port surface 36 and the substrate A described later are applied, is S, the volume represented by S × L × W is preferably 5 to 100%, more preferably. Is 10 to 50%. If it is less than this range, the amount of movement from the discharge port 34 in the longitudinal direction after discharge is small and the moving speed is low, so that it is practically impossible to eliminate voids formed in other portions. If the discharge amount is larger than the above range, the coating liquid overflows from the gap formed between the discharge port surface 36 and the substrate A, so that the film thickness at the start of coating becomes greater than the allowable value. Furthermore, after discharging the above discharge amount from the discharge port 34, it is necessary to wait for a certain time. This time is required for the discharged coating liquid to hang down from the discharge port 34 and to be uniform over the longitudinal direction of the die 20 by the action of surface tension, and is preferably 0.1 to 10 seconds, more preferably 0. .3 to 3 seconds. If it is shorter than this, it will not be uniform, and if it is longer than this, the tact time will be greatly increased, which is not preferable.
[0034]
In parallel with the above operation, the stage 6 starts to move, and the thickness of the substrate A through which the substrate A passes under the thickness sensor 120 is measured. When the coating start portion of the substrate A reaches just below the discharge port 34A of the die 20, the stage 6 is stopped. At this time, using the measured thickness data of the substrate A, the vertical lift unit 70 is driven to bring the discharge port surface 36 of the die 20 close to the position separated from the substrate A in advance by the clearance. Then, the piston 54 of the syringe pump 50 is raised at a predetermined speed, and after a certain period of time when the coating liquid 66 is discharged from the die 20, the table 6 starts to move at a predetermined speed, and coating of the coating liquid 66 on the substrate A is started. A film C is formed. When the coating end portion of the substrate A comes to the position of the discharge port 34 of the die 20, the piston 54 is stopped to stop the supply of the coating liquid 66, and then the vertical lift unit 70 is driven to raise the die 20. As a result, the bead formed between the substrate A and the die 20A is cut off, and the application is completed.
[0035]
During these operations, the table 6 continues to move, stops when it 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 lower surface of the substrate A is held by an unloader (not shown), and the substrate A is transported to the next step. When the substrate A is delivered to the unloader, the table 6 lowers the lift pins and returns to the origin position. After returning to the origin position of the table 6, the wiping unit 90 is moved so that the tray 100 is disposed below the discharge port 34 of the die 20.
[0036]
Thereafter, the syringe pump 50A is operated, a small amount of 10 to 500 μL of the coating liquid is fed into the die 20, and the voids remaining inside the die 20 are filled with the coating liquid.
[0037]
After completion, the syringe pump 50 opens the suction valve 44, closes the supply valve 42, lowers the piston 54 at a constant speed, and fills the syringe 52 with the coating liquid 66 in the tank 64. After the filling is completed, the piston 54 is stopped, the suction valve 44 is closed, the supply valve 42 is opened, the next substrate A is waited for, and the same operation is repeated.
[0038]
In the above coating method, a small fixed amount of coating liquid is discharged from the discharge port 34 of the die 20 before the start of coating, and the coating is always performed without any gaps in the slit 28 and the vicinity of the discharge port 34. The application start part is as shown in FIG. 3B, and completely prevents the occurrence of film breakage, which is a part where the application start part is not applied, as shown in FIG. Can do.
[0039]
In the above description of the embodiment, the means for cleaning the vicinity of the die discharge port by sliding the elastic body wiping head 92 near the discharge port of the die is shown. Alternatively, means for wiping the vicinity of the discharge port of the die with a cloth material moistened with a solvent may be used.
[0040]
Next, the second coating method of the present invention will be described.
[0041]
First, the coating liquid is filled from the tank 64 to the die 20 and the stage 6, the die 20, and the wiping unit 90 are arranged to the standby position, which is exactly the same as the first coating method.
[0042]
First, the substrate A is placed on the upper surface of the table 6 and sucked and held via a lift pin from a loader (not shown). Then, the coating liquid supply device 40 is operated to discharge a small amount of the coating liquid 66 toward the tray 100, the die 20 is lowered, the discharge port surface 36 of the die 20 is engaged with the wiping head 92, and then the wiping head 92 is moved. By sliding in the longitudinal direction of the die 20, the vicinity of the discharge port 34 of the die 20 is cleaned over the longitudinal direction of the die. After the cleaning is completed, the wiping unit 90 returns to the original place (the right end in FIG. 1).
[0043]
The subsequent operations of the stage 6, the die 20, and the syringe pump 50 will be described with reference to the time chart of FIG. After confirming that the wiping unit 90 has moved to the right end of the base 2, the stage 6 on which the substrate A is placed starts to move. At this time, the die 20 is in a wiping position far above the position where application is performed, while the syringe pump 50 is still on standby. Then, the substrate thickness is measured when the substrate A passes under the thickness sensor 120, and the stage 6 is stopped when the coating start portion of the substrate A reaches just below the discharge port 34 </ b> A of the die 20. At this time, the measured thickness data of the substrate A is used to drive the vertical lift unit 70 so that the clearance between the discharge port surface 36 of the die 20 and the substrate A becomes a predetermined first clearance. Is lowered to the first lowered position. Then, the syringe pump 50 is driven to discharge a certain amount of coating liquid from the discharge port 34 of the die 20 to form a bead. After a certain time, the die 20 is moved in the vertical direction to the second lowered position so that the clearance between the discharge port surface of the die 20 and the substrate A becomes the second clearance. The second clearance is preferably set so as to maintain the bead once formed. In this state, the piston 54 of the syringe pump 50 is raised at a predetermined speed, the coating liquid 66 is discharged from the die 20, and the bead grows to a predetermined size after a predetermined time, and then the table 6 starts moving at a predetermined speed. Then, the coating film C is formed by starting the coating of the coating liquid 66 on the substrate A. At this time, the discharge of the coating liquid from the die 20 and the relative movement of the table 6 with the die 20 may be started simultaneously, or the relative movement of the table 6 with the die 20 may be accelerated. The timing at which the piston 54 of the syringe pump 50 reaches the predetermined speed and the timing at which the table 6 reaches the predetermined speed may be any, but it is preferable that the table 6 reaches the predetermined speed at the same time or later. .
[0044]
When the coating end portion of the substrate A comes to the position of the discharge port 34 of the die 20, the piston 54 is stopped to stop the supply of the coating liquid 66, and then remains between the discharge port surface of the die 20 and the substrate A. After applying a so-called squeegee in which a part of the coating solution being transferred is transferred to the substrate A as the substrate A moves, the vertical lift unit 70 is driven to raise the die 20. As a result, the bead formed between the substrate A and the die 20A is cut off, and the application is completed.
[0045]
During this time, the table 6 continues to operate, stops when it 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 lower surface of the substrate A is held by an unloader (not shown), and the substrate A is transported to the next step. When the substrate A is delivered to the unloader, the table 6 lowers the lift pins and returns to the origin position. After returning to the origin position of the table 6, the wiping unit 90 is moved so that the tray 100 is disposed below the discharge port 34 of the die 20.
[0046]
Thereafter, the syringe pump 50A is operated, a small amount of 10 to 500 μL of the coating liquid is fed into the die 20, and the voids remaining inside the die 20 are filled with the coating liquid.
[0047]
After completion, the syringe pump 50 is operated to fill the syringe 52 with the application liquid 66 in the same manner as the first application. After the filling is completed, the piston 54 is stopped, the suction valve 44 is closed, the supply valve 42 is opened, the next substrate A is waited for, and the same operation is repeated.
[0048]
In the above application method, the first clearance is preferably 20 to 200 μm, and the second clearance is preferably 40 to 300 μm. After the first clearance is set, a certain amount of coating liquid is discharged from the discharge port 34 of the die 20, so that even if there is a minute gap near the discharge port 34 of the slit 28, 1) the discharge port 34. 2) The coating liquid discharged from the discharge port 34 flows through the gap formed between the discharge port surface 36 and the substrate A in the longitudinal direction of the die 20 by a kind of capillary phenomenon. Therefore, even if the gap of the slit 28 is poured out by the coating liquid and remains in the gap between the discharge port surface 36 near the discharge port 34 and the substrate A, the clearance is caused by the coating liquid transmitted by the capillary tube. Since the coating liquid is discharged between the discharge port surface 36 and the substrate A in the longitudinal direction to form a bead, the gap does not affect subsequent coating. At this time, the discharge amount of the coating liquid from the discharge port 34 is the length L of the discharge port surface 36 of the die 20 shown in FIG. 4 in the application direction (arrow direction), and the clearance between the discharge port surface 36 and the substrate A. The volume V = L × S × W formed by the first clearance S as a quantity and the longitudinal length W of the discharge port 34 is preferably 5 to 100%, more preferably 10 to 50%. The bead 130 in which the coating liquid is connected between the discharge port surface 36 and the substrate A is formed by the coating liquid discharge amount defined by this, but if the coating liquid discharge amount is smaller than this range, the coating liquid is discharged by the capillary tube. When the flow rate in the longitudinal direction of the die is very slow and the tact time of coating is also slowed, on the other hand, when it is larger than the above range, the time for the coating solution to flow quickly in the longitudinal direction of the die 20 and discharge the voids is greatly reduced. However, the coating liquid protrudes from the gap formed by the discharge port surface 36 and the substrate A, and the subsequent coating cannot be performed normally.
[0049]
If the first clearance is smaller than the above range, the substrate A may collide with the discharge port surface due to uneven thickness of the substrate. If the first clearance is larger than the above range, a gap is formed between the substrate A and the discharge port surface 36. The speed at which the coating liquid is passed through the gaps by the capillaries becomes extremely small, and it becomes impossible to form a bead by eliminating the voids and connecting the coating liquid within a short time. Furthermore, if the second clearance is smaller than the above range, the shearing force acting on the coating liquid during coating increases, and defects such as film breakage occur during coating. If larger than the above range, the first clearance causes The formed bead is cut, and a film cut portion that is not applied to the application start portion is generated.
[0050]
The first clearance may be the same as the second clearance, but is preferably smaller than the second clearance. The smaller the first clearance, the faster the flow rate in the longitudinal direction of the die due to the capillary effect of the coating liquid discharged from the discharge port 34, and the larger the second clearance, the discharge port surface. Since the upper limit coating liquid discharge amount allowed in the gap formed between the substrate 36 and the substrate A is increased, the operation margin for controlling the film thickness at the coating start portion is increased, and the film thickness control at the coating start portion is performed. This is because it becomes easier. On the contrary, if the second clearance is reduced, the allowable volume formed by the clearance between the discharge port surface 36 and the substrate A is reduced by reducing the clearance. This causes inconveniences such as soiling the uncoated part.
[0051]
Furthermore, the first clearance is set so that a fixed amount of the coating liquid is discharged from the discharge port 34, and the second clearance can be set after waiting for a certain time. This waiting time is preferably 0.1. 10 seconds, more preferably 0.3 to 3 seconds. If the length is shorter than this, the coating liquid is connected to the gap formed between the substrate A and the discharge port surface 36 by a capillary tube, and the gap is eliminated and the coating liquid is connected to form a bead for a longer time. As a result, the tact time is significantly increased, which becomes an obstacle to productivity improvement.
[0052]
As described above, by setting a first clearance and discharging a certain amount of coating liquid, the gap in the slit 28 is excluded from the discharge port 34 and remains outside the die 20 in the vicinity of the discharge port 34. The gap is further eliminated by the coating liquid that moves in the longitudinal direction of the die due to the capillary effect, so that the coating liquid fills the clearance between the discharge port surface 36 and the substrate A to form a bead that is connected in the longitudinal direction. To do. When the application is subsequently started with the second clearance that can maintain this bead, a portion that is not applied as shown in FIG. 3A does not occur in the application start portion, and the application start portion as shown in FIG. Thus, it can be applied without application defects. By eliminating the non-applied portion, it is possible to reduce the streak defect that occurs from the non-applied portion as a starting point, and the non-product partial region with non-uniform thickness caused by the non-applied portion. In addition, since the above application method can be applied regardless of the type and application amount of the application liquid, in order to eliminate the unapplied part of the application start part, the composition or solid content concentration of the application liquid is changed or the application quantity is increased. There is no need. In particular, by increasing the coating amount, it is possible to completely eliminate the inconvenience that the coating liquid flows due to the substrate tilt in the section from the coating to the drying and the film thickness uniformity is hindered. This coating method can also be applied to coaters that use pre-coating on the rolls to eliminate the unapplied part of the coating start part, thereby eliminating any pre-coating on the rolls. It is possible to eliminate the consumption of an invalid coating solution accompanying the coating, and it is possible to shorten the tact time as much as the preliminary coating is not performed.
[0053]
In addition, as a coating liquid which can apply this invention, a viscosity is 1-1000 mPaS, More desirably, it is 1-50 mPaS, and it is preferable from a coating property that it is Newtonian, However, It is applicable also to the coating liquid which has thixotropy. In particular, it is effective when a coating solution using a solvent having high volatility such as PGMEA, butyl acetate, ethyl lactate or the like is applied. Specific examples of the coating solution that can be applied include a black matrix for a color filter and a coating solution for forming a color pixel, a resist solution, an overcoat material, and the like. 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, the coating state and coating speed to be used are 0.1 m / min to 10 m / min, more preferably 0.5 m / min to 6 m / min, the die lip gap is 50 to 1000 μm, more preferably 80 to 200 μm, and the coating thickness. Is 1 to 50 μm, more preferably 2 to 20 μm in a wet state.
[0054]
【Example】
A color filter was manufactured using the die coater 1.
The die had a length in the longitudinal direction of the ejection port of 360 mm, a length in the coating direction of the ejection port surface of 0.5 mm, a gap of the slit of 100 μm, and a coating film having a width of 360 mm could be formed on the substrate.
[0055]
First, after cleaning an alkali-free glass substrate having a thickness of 360 mm × 465 mm and a thickness of 0.7 mm, a black matrix coating solution was applied at a thickness of 10 μm and a clearance of 100 μm between the die and the substrate at 3 m / min. Application is performed by wiping the vicinity of the die outlet with silicon rubber having the same shape as the outlet, and then bringing the die close to the application start portion of the substrate where the die is stopped with a clearance of 100 μm, and a coating solution corresponding to a wet thickness of 10 μm. Was sent from a syringe pump, and the movement of the substrate A was started 0.5 seconds after the pumping was started. The black matrix coating solution applied at this time is a photosensitive solution in which titanic acid nitride is used as a light shielding material, acrylic resin is used as a binder, and PGMEA is used as a solvent, and the solid content concentration is adjusted to 10% and the viscosity is adjusted to 10 mPaS. Using. Also, because the coating thickness is small, there were five locations in the substrate width direction that were not applied to the coating start part, so the die was stopped after wiping the vicinity of the die outlet with silicon rubber having the same shape as the outlet The substrate is placed close to the coating start part with a clearance of 100 μm, 5 μL of the black matrix coating solution is discharged, and after waiting for 0.1 seconds, the coating solution corresponding to a wet thickness of 10 μm is sent from the syringe pump. Then, the movement of the substrate A was started 0.2 seconds after the start of pumping. As a result, all the portions that were not applied to the application start portion were eliminated. The tact time for coating was 30 seconds. The coated substrate is dried for 10 minutes on a hot plate at 100 ° C., exposed, developed, and peeled off, then heated for 30 minutes on a 260 ° hot plate, cured, and the pitch is increased in the width direction of the substrate. 254 μm, pitch in the longitudinal direction of the substrate is 85 μm, line width is 20 μm, number of RGB pixels is 4800 (substrate longitudinal direction) × 1200 (substrate width direction), diagonal length is 20 inches (substrate width direction is 305 mm, substrate) A black matrix film having a lattice shape of 406 mm in the longitudinal direction and a thickness of 1 μm was prepared. In addition, when the coating thickness was measured in the state before the grid pattern was formed after drying, the substrate running direction and the width direction had a non-uniformity of ± 3% or less except for 10 mm at the end.
[0056]
After wet cleaning, the R color coating solution was applied at a thickness of 20 μm and a clearance of 100 μm between the die and the substrate at 3 m / min. The coating solution for R color was a photosensitive solution prepared by mixing an acrylic resin as a binder, PGMEA as a solvent, and Pigment Red 177 as a pigment, mixing them at a solid concentration of 10%, and adjusting the viscosity to 5 mPaS. The coated substrate is dried on a hot plate at 90 ° C. for 10 minutes, and then exposed, developed, and peeled off, leaving an R color coating film with a thickness of 2 μm only on the R pixel portion, and heated on a 260 ° hot plate for 30 minutes. Then, it was cured. Subsequently, a G matrix coating solution was applied to a substrate on which a black matrix and an R color coating film were formed, with a thickness of 20 μm and a clearance of 100 μm between the die and the substrate at 3 m / min, and then on a hot plate at 100 ° C. After drying for 10 minutes, exposure / development / peeling was performed to leave a G color coating film having a thickness of 2 μm only in the G color pixel portion, and curing was performed by heating for 30 minutes on a 260 ° C. hot plate. Further, a B-color coating solution is applied to a substrate on which a black matrix, R-color, and G-color coating film is formed at a thickness of 20 μm, a clearance of 100 μm between the die and the substrate at 3 m / min, and then hot at 100 ° C. After drying for 10 minutes on the plate, exposure, development and peeling were performed to leave a B-color coating film having a thickness of 2 μm only on the B-color pixel portion, and curing was performed by heating for 30 minutes on a 260 ° C. hot plate. The G-color coating solution is an R-color coating solution and the pigment is Pigment Green 36 and the viscosity is adjusted to 10 mPaS at a solid content concentration of 10%. The B-color coating solution is an R-color coating solution. Pigment Blue 15 having a solid concentration of 10% and a viscosity adjusted to 10 mPaS. All of the R, G, and B color coating solutions are applied by wiping the vicinity of the die outlet with silicon rubber, and then approaching the coating start portion of the substrate where the die is stopped with a clearance of 100 μm, and a wet thickness of 20 μm. The coating liquid corresponding to was sent from the syringe pump, and the movement of the substrate A was started 0.3 seconds after the pumping was started. The tact time for coating was 30 seconds. The coating quality was satisfactory. The film thickness distribution was also measured for each color after drying. The film thickness distribution was good with a fluctuation of ± 3% or less in the substrate running direction and width direction excluding the edge of 10 mm.
[0057]
Finally, ITO was deposited by sputtering. With this manufacturing method, 1000 color filters were produced. The obtained color filter had no coating unevenness, the chromaticity was uniform over the entire surface of the substrate, and the quality was satisfactory.
[0058]
【The invention's effect】
Application method according to the present invention The law If it is used, a certain amount of coating solution is discharged from the applicator, and after waiting for a certain period of time, the formation of the coating film on the member to be applied is started, so even if there is a gap inside the applicator near the discharge port Since the gap is discharged to the outside of the applicator and the gap is completely eliminated by the coating liquid flowing in the longitudinal direction outside the discharge port, the high-quality film and the film can be formed from the coating start portion without performing preliminary coating. Uniform coating can be performed. Furthermore, it is possible to easily achieve high-quality and uniform film thickness over the entire surface of the substrate without pre-coating for any type of coating liquid and coating conditions. Cost reduction by reduction can be realized.
[0059]
According to the method for manufacturing a display member according to the present invention, the display member is manufactured using the above-described excellent coating method. Therefore, a high-quality display member can be manufactured at low cost. .
[Brief description of the drawings]
FIG. 1 is a schematic front sectional view of a die coater 1 according to an embodiment of the present invention.
FIG. 2 is a time diagram showing an operation state of each operation unit when coating is performed using the die coater 1;
FIG. 3 is a plan view showing a coating state on a substrate.
4 is a schematic perspective view showing a bead formation state of the die 20 and the substrate A. FIG.
[Explanation of symbols]
1 Die coater
2 base
4 Guide rail
6 stages
10 props
20 die (applicator)
22 Front lip
24 rear lip
26 Manifold
28 slits
32 Sim
34 Discharge port
36 Discharge port surface
40 Coating solution supply device
42 Supply valve
44 Suction valve
50 syringe pump
52 syringe
54 Piston
56 body
60 Supply hose
62 Suction hose
64 tanks
66 Coating liquid
68 Air pressure source
70 Vertical elevator unit B
72 motor
74 Guide
78 Lift platform
80 Suspension holding stand
90 Wiping unit
92 Wiping head
94 Bracket
96 slider
98 Drive unit
100 trays
102 trolley
120 Thickness sensor
122 Support stand
130 beads
200 Controller
202 Operation panel
A Substrate (Coating member)
C Coating film

Claims (3)

An applicator having a discharge port extending in one direction is brought close to the member to be coated, the coating liquid is supplied from the coating liquid supply means to the coating device, and the coating liquid is discharged from the discharge port of the coating device. In a coating method in which a coating film is formed on a member to be coated by moving any of the members relatively in the horizontal direction, the coating device is brought close to the stationary member to be coated with a first clearance before coating. A constant volume Q of the coating liquid is discharged from the container, and after waiting for a certain period of time, the coating apparatus is moved so that the second clearance is larger than the first clearance, and then the coating liquid is discharged from the coating apparatus to the member to be coated; A coating method comprising: starting relative movement of a member to be coated with respect to an applicator to form a coating film on the member to be coated . The constant volume Q of the coating liquid discharged from the discharge port of the applicator is set such that the length in the application direction of the surface including the discharge port of the applicator is L, the length of the applicator in the longitudinal direction of the discharge port is W, and the constant volume Q is If the clearance between the applicator and the object to be coated member when ejecting the S, claim 1, wherein Q = α2 × S × L × W, that is 0.05 ≦ α2 ≦ 1.0, The coating method described in 1. Method for producing a display member, which comprises producing a member for a display using any of the coating method according to claim 1-2.

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