JP5061421B2 - Coating method and manufacturing method of display member - Google Patents

Description

The present invention is used, for example, in the field of manufacturing color filters for color liquid crystal displays, array substrates for TFTs, optical filters, printed circuit boards, integrated circuits, semiconductors, and the like. The present invention relates to an application method for forming a coating film while discharging a coating liquid and a method for producing a display member such as a color filter or an array substrate for TFT using the application method .

  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 forms red, blue and green after forming a black coating on the glass substrate. In this way, the coating film is formed in three primary colors on the glass substrate.

  Therefore, for the production of a color filter, a forming process is required in which black, red, blue, and green coating liquids are sequentially applied onto a glass substrate to form the coating film. In this type of forming process, spinners can be easily used to form uniform coatings, and have been widely used. Recently, however, the consumption of expensive coating liquids has been reduced, and glass with a width of more than 1 m has been used. Along with the increase in size of the device corresponding to the substrate, many die coaters have been introduced.

  As an example of this type of die coater, a reciprocable table and a coating head (die) having a downward discharge port are provided, and after the glass substrate is adsorbed and held on the table, the glass substrate is used together with the table. However, there is a technique in which a coating liquid is discharged from a discharge port of a coating head as the coating head moves directly below, and a coating film is continuously formed on a glass substrate (for example, Patent Document 1).

  In recent years, as the quality of products has improved, the accuracy of film thickness distribution required for die coaters to be applied to a substrate has become higher. For example, the film thickness unevenness of ± 3% or less excluding the edge 10 mm. It is hoped that.

  In general, large film thickness fluctuation occurs not in the coating direction and the substrate width direction, which is the longitudinal direction of the die, but in the end portion, not the central portion. For the end in the width direction, since the film thickness profile of the coating film is determined by the characteristics of the coating liquid, the adjustment of the characteristics of the coating liquid is the main improvement means.

  On the other hand, for the end in the coating direction, the film thickness control at the coating start part and the coating end part greatly affects the film thickness profile formation that minimizes the defective film thickness section that does not reach the target film thickness accuracy. Many improvement means for shortening the defective film thickness section and increasing the section with high film thickness accuracy have been proposed.

  For the coating start part, in order to prevent the film from becoming thicker, a clearance between the substrate and the die is controlled in conjunction with the discharge of the coating liquid and the horizontal movement of the die with respect to the substrate (for example, a patent) Document 2), a method in which the substrate is kept stationary, and the substrate starts moving after a certain period of time when the pump is driven to start discharging (for example, Patent Document 3). There is a method (for example, Patent Document 4) in which the product part is applied when it is applied to the top and the pump discharge and the substrate movement are both stable.

On the other hand, with respect to the application end portion, there is one that forms the film thickness profile of the application end portion by setting the application end position and determining the discharge stop of the coating liquid before the application end position (for example, Patent Document 5). .
JP-A-6-339656 (5th column 18th line to 7th column 25th line, 10th column 9th line to 43rd line, FIG. 1) JP 2002-113411 A (column 4, line 48 to column 5, line 24, column 9, line 3 to line 31, FIGS. 1 and 5) JP-A-8-229482 (column 13, line 46 to column 15, line 48, FIG. 3) JP 7-328515 A (column 9, line 49 to column 10, line 46, FIG. 1) JP-A-6-339656 (Claim 4, 11th column, 33rd line to 12th column, 26th line, FIGS. 10, 12, and 13)

  The film thickness profile control means at the coating start and end portions can change the film thickness profile by changing the parameters. However, even if the parameters are changed in the smallest unit possible on the apparatus, the change in the film thickness profile is so large that the desired film thickness profile cannot be adjusted sufficiently. There is a problem that a defective film thickness interval that does not reach the film thickness accuracy becomes long and a high film thickness accuracy interval cannot be lengthened.

The present invention has been made based on the above-mentioned circumstances, and the object is to finely adjust the film thickness profile of the coating film at the coating start part and end part to form a desired film thickness profile shape. Showing the means, minimizing the defective film thickness section that does not reach the target film thickness accuracy occurring at the coating start part and end part, thereby maximizing the coating film having high film thickness distribution accuracy on one coated member It is an object of the present invention to provide a coating method that can be easily realized and a method for manufacturing a display member using this method.

  The above object is achieved by the means described below.

In the coating method of the present invention, after the applicator having a discharge port extending in one direction is brought close to the member to be coated and both are stationary, the discharge is stopped after discharging the volume Qp of the coating liquid from the applicator. By forming a bead between the discharge port of the applicator and the coated member by waiting for a certain time while the coated member is stationary, the coating liquid is discharged from the coating device to the coated member and the coated member is applied. This is a method of starting relative movement with respect to the container and forming a coating film on the member to be coated, and by adjusting the volume Qp, the coating film thickness profile shape of the coating start part is formed into a desired shape. It is characterized by.

According to another coating method of the present invention, an applicator having a discharge port extending in one direction is brought close to a member to be coated, and after both of them are stationary, after discharging the coating liquid from the applicator, the discharge is stopped and the applicator and the coating are stopped. By forming a bead between the discharge port of the applicator and the member to be coated by waiting for a certain period of time while the coating member is stationary , the coating liquid is supplied from the constant-capacity pump to the applicator and then applied to the member to be coated. In the coating method in which the coating liquid is discharged and the coating member is moved relative to the coating device to form a coating film on the coating member, the constant-capacity pump from the start of coating to form a coating film once. By adjusting the total volume Qt of the coating solution supplied to the applicator, the film thickness profile shape of the coating film at the coating end position is formed into a desired shape.

  The manufacturing method of the display member of the present invention is characterized in that the display member is manufactured using the coating method of the present invention described above.

With the coating method according to the present invention, the coating liquid supplied to the applicator from a constant displacement pump volume is adjusted, the desired thickness profile of the coating film end portions and the coating start portion is adjusted finely Since the film can be formed in a shape, the defective film thickness section that does not reach the target film thickness accuracy occurring in the coating start part and the end part can be minimized. As a result, a coating film having high film thickness distribution accuracy can be obtained maximally and easily on one coated member. As a result, the non-product portion in one coated member can be minimized, and the usage efficiency of the coated member can be increased.

  According to the method for producing a display member according to the present invention, the above-described excellent coating method is used to produce a display member. Therefore, the coating film thickness distribution accuracy and quality are high, and there are few unnecessary portions. Therefore, it is possible to manufacture a display member with high product efficiency at a low cost.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic front sectional view of a die coater 1 which is an apparatus for carrying out a coating method according to the present invention , and FIG. 2 is a time line diagram showing an operation state of each operating unit when coating is performed using the die coater 1. FIG. 3 is a film thickness profile diagram showing changes in the film thickness profile at the coating start portion when the initial delivery amount Qp and the standby time t are independently changed, and FIG. 4 is an operation of the die coater 1 at the end of coating. FIG. 5 is a film thickness profile diagram showing changes in the film thickness profile at the coating end portion when the pump stop position Xp and the coating liquid total discharge amount Qt are independently changed. .

FIG. 1 shows an embodiment of a die coater 1 for carrying out the coating method of the present invention . The die coater 1 includes a base 2, and a pair of guide rails 4 is provided on the base 2. Is provided. On the guide rail 4, a mounting table for the substrate A as a member to be coated, that is, a stage 6 is arranged. The stage 6 is driven by a linear motor (not shown) and reciprocates freely in the X direction indicated by an arrow in FIG. The upper surface of the stage 6 is a vacuum suction surface made of suction holes, and can hold the substrate A by suction.

  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.

  The die 20 includes a front lip 22 and a rear lip 24 that extend in a direction orthogonal to the X direction (a direction perpendicular to the paper surface) and are overlapped in the X direction via a shim 32 and integrated with a plurality of connection bolts (not shown). Is bound to. 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 lowermost 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.

  The vertical lifting / lowering device unit 70 that lifts and lowers the die 20 includes a suspension holding base 80 that holds the die 20 in a suspended form, a lifting base 78 that lifts and lowers the suspension holding base 80, and a guide that guides the lifting base 78 in the vertical direction. 74, and a ball screw 76 that converts 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 between the substrate A on the stage 6 and the discharge port surface 36 of the die 20 in an arbitrary size.

  Further, when the right end 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 34 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 liquid 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.

  Furthermore, when the left side of the base 2 is viewed, a thickness sensor 120 that measures 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.

  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.

  The coating liquid supply device 40 includes a filter 46, 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 type pump that fills a syringe 52 having a constant inner diameter with a coating liquid, pushes it out by a piston 54, and supplies a single substrate A to the die 20. 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 the syringe 52. Push up and discharge the coating solution inside. In the syringe pump 50, it is preferable that an O-ring (not shown) is attached to the piston 54 or the syringe 52 as a sealing material in order to provide airtightness between the male-side piston 54 and the female-side syringe 52.

  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 130. 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 132, the change parameter is transmitted to the control device 130, and the change of the driving operation can be realized. In particular, in the coating liquid supply apparatus 40, the syringe pump 50, the supply valve 42, and the suction valve 44 are electrically connected, and the electrical signal and measurement value are taken into the control apparatus 130, Any operation can be performed according to the command. If the control device 130 is used, the operations of the coating liquid supply device 40, the up-and-down lift unit 70, and the stage 6 can be freely controlled. It is possible to control the operation of each part.

  Next, the first coating method according to the present invention using the die coater 1 will be described in detail.

  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. The state of the coating liquid supply device 40 at this time is such that 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 at the lowermost position. 20 can be supplied.

  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).

  Subsequent operations of the stage 6, the die 20, and the syringe pump 50 will be described with reference to the time diagram 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 at a wiping position far above the position where the application is performed, while the syringe pump 50 is stopped and is 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 of the die 20. At this time, by using the measured thickness data of the substrate A, the vertical lifting unit 70 is driven 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. The first clearance is preferably 20 to 100 μm, more preferably 30 to 60 μm. And the syringe pump 50 is driven, the coating liquid of the initial delivery amount Qp is discharged from the discharge port 34 of the die | dye 20, and a bead is formed by waiting for a fixed time. The fixed waiting time after discharging the initial delivery amount Qp is, for example, preferably 0.1 to 10 seconds, more preferably 1 to 3 seconds. Then, after forming the bead, the die 20 is moved up and down 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, preferably 70 to 200 μm, more preferably 80 to 120 μm. In this state, the piston 54 of the syringe pump 50 is raised at a predetermined speed, and the discharge of the coating liquid 66 from the die 20 is started. After the waiting time t seconds, the bead grows to a predetermined size, and then the table 6 is moved. The movement is started at a predetermined speed, and the coating liquid C is formed by starting application of the coating liquid 66 to the substrate A. Here, the film thickness profile of the coating start portion can be adjusted by changing the initial amount Qp or the waiting time t. The time tp for the piston 54 of the syringe pump 50 to reach a predetermined speed and the time tt for the table 6 to reach a predetermined speed are preferably shorter because the unstable region becomes smaller. Therefore, it is preferably 80 to 400 ms, more preferably 100 to 200 ms. Moreover, it is preferable that tp ≧ tt. This is because the target film thickness is reached after both the pump and the table have reached the predetermined speed, and the amount of movement of the table is greater when the pump is raised to the predetermined speed before the table reaches the predetermined speed. This is because an unstable region that does not reach the target film thickness can be shortened because it is small.

  Then, as shown in FIG. 4, when the position Xp slightly before the application end position Xe of the substrate A comes to the position of the discharge port 34 of the die 20, the piston 54 is stopped and the supply of the application liquid 66 is stopped. At this time, since the table 6 continues to move at the same speed as the time of application, a part of the application liquid remaining between the discharge port surface of the die 20 and the substrate A reaches the application end position Xe. 6 is transferred to the substrate A as the substrate A moves on the substrate 6. When the application end position Xe of the substrate A comes directly below the discharge port 34 of the die 20, 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.

  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.

  Thereafter, the syringe pump 50 is operated to feed a small amount of 10 to 500 μL of the coating solution into the die 20 and fill the voids remaining inside the die 20 with the coating solution.

  After completion, the suction valve 44 is opened, the supply valve 42 is closed, the piston 54 is lowered, and the application liquid 66 is filled into the syringe 52. 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.

  In the first coating method of the present invention described above, the film thickness profile at the coating start portion can be adjusted by both the standby time t and the initial delivery amount Qp. This is because the film thickness profile of the coating start portion depends on the size of the bead formed between the discharge port surface 36 of the die 20 and the substrate A before the stage 6 starts to move. The size of the bead varies depending on the waiting time t and the initial amount Qp. If the bead size is large, the film thickness profile overshoots from the target film thickness at the coating start portion. Conversely, if the bead size is small, the film thickness profile undershoots the target film thickness. As described above, since the film thickness depends on the size of the bead, the waiting time t may be 0 (zero) if there is an initial amount Qp. That is, the film thickness profile of the coating start portion may be adjusted by changing the bead size only by the initial delivery amount Qp with the stop time t = 0.

  FIG. 3 shows a change in the film thickness profile at the coating start portion when the initial delivery amount Qp and the standby time t are independently changed. In FIG. 3, when only the initial amount Qp is changed by 5 mcc from the state of the broken line, the target film thickness profile of the solid line, that is, the target film thickness target section is the longest and the defective film thickness section where the predetermined film thickness is not reached. Can be adjusted to the shortest shape, but when only the waiting time t is changed by 0.01 seconds, a film thickness profile of a one-dot chain line that overshoots the target is obtained. From this, it can be said that changing the initial amount Qp by 5 mcc can change the film thickness profile more finely than changing the waiting time t by 0.01 seconds. In actual device accuracy, it is almost the limit to change the waiting time t every 0.01 seconds, but the initial delivery amount Qp by the syringe pump 50 can be accurately discharged even at 1 mcc. Therefore, the film thickness profile can be adjusted more finely and accurately by adjusting the initial extraction amount Qp. In the actual adjustment of the film thickness profile, it is preferable to use the standby time t for coarse adjustment and to use the initial amount Qp for fine adjustment. In the above, an example is shown in which the application is started after waiting for a certain time after the initial dispensing amount Qp is discharged, but also when the application is started subsequent to discharging the initial dispensing amount Qp, The present invention is applicable.

  In the first coating method described above, since the initial dispensing amount Qp is adjusted, that is, by changing the size of the initial dispensing amount Qp, the film thickness profile of the coating film C at the coating start portion can be finely adjusted. The film thickness profile of the film can be easily formed into a desired shape. Here, the desired shape of the film thickness profile of the coating film C at the coating start portion means that the defective film thickness section that does not reach the target film thickness accuracy generated at the coating start portion is minimized. To do. In this case, the shorter the length of the defective film thickness section, the longer the portion reaching the target film thickness accuracy of the coating film. By adjusting the initial delivery amount Qp, the length of the defective film thickness section is preferably 20 mm or less, more preferably 10 mm or less from the coating start portion.

  Next, the second coating method according to the present invention will be described. The second coating method improves the method for adjusting the film thickness profile of the coating film C at the coating end portion with respect to the first coating method. That is, in the first application method, the position Xp before the application end position Xe is detected and the supply of the syringe pump 50 is stopped. However, in the second application method of the present invention, the syringe pump 50 is stopped. The position is controlled not by the position Xp but by the total discharge amount Qt that is the total volume of the coating liquid supplied from the start of coating to form the coating film C from the syringe pump 50 to the die 20. Since the total discharge amount Qt of the syringe pump 50 can be finely adjusted in units of 1 mcc, control in the micron order in terms of position is possible. On the other hand, the control method based on the position of the stage 6 transmits a signal to the syringe pump 50 after detecting the position, so that the control in units of 1 mm is the limit. The reason why 1 mm is the limit is that, for example, when coating is performed at 100 mm / s, 1 mm corresponds to 0.01 seconds, and changes by 1 mm due to a slight timing shift.

  In the second coating method, as described above, the film thickness profile of the coating film C at the coating end portion can be finely adjusted, so that the film thickness profile of the coating film C can be formed in a desired shape. Here, the desired shape of the film thickness profile of the coating film C at the coating end portion means that the defective film thickness section that does not reach the target film thickness accuracy occurring at the coating end portion is minimized. In this case, the shorter the length of the defective film thickness section, the longer the part reaching the target film thickness accuracy of the coating film C, which is desirable. By adjusting the total discharge amount Qt, which is the total volume of the coating liquid supplied from the start of coating to form the coating film C from the syringe pump 50 to the die 20, the defective film thickness section of the coating film C at the end portion is coated. It is preferably 20 mm or less, more preferably 10 mm or less from the end portion.

  Next, an example will be shown in which the film thickness profile at the coating end portion of the coating film C can be finely adjusted to a desired shape by adjusting the total discharge amount Qt. FIG. 5A shows the case where only the coating liquid total discharge amount Qt from the syringe pump 50 is changed, and FIG. 5B shows the case where only the stop position Xp of the syringe pump 50 is changed. The change in the film thickness profile at the end of coating is shown.

  In FIG. 5B, the broken line indicates the film thickness profile at the coating end portion of the coating film C when the stop position Xp = 490 mm, and the solid line indicates the stop position Xp = 491 mm. In the wavy line, the section with a constant film thickness ends at a position of 491 mm, and the film thickness starts to decrease. On the other hand, the solid line only increases the stop position Xp by 1 mm, but the section with a constant film thickness at a position of 495 mm. After finishing, the film thickness decreases once after overshooting.

  On the other hand, in FIG. 5 (a), the broken line indicates that the syringe pump 50 is stopped at the stop position Xp = 490 mm (same as the dashed line in FIG. 5 (b)), whereas the solid line indicates the syringe pump 50 from the state of the dashed line. Only the total discharge amount Qt is increased by 10 mcc. The solid line has a constant film thickness section at the position of 497 mm, and the film thickness starts to decrease, the constant film thickness section is longer than any other, and the defective film thickness section is not uniform. . In other words, controlling the total discharge amount Qt from the syringe pump 50 can change the film thickness profile much finer and adjust it to a desired shape. In addition, the control by the total discharge amount of the syringe pump 50 is superior in terms of reproducibility because no signal is transmitted and received, compared to detecting the position and stopping the syringe pump 50. Therefore, it is preferable to adjust the film thickness profile at the coating end part by the total discharge amount of the syringe pump 50 regardless of fine adjustment or rough adjustment. You may mix and use.

  Further, when the second coating method described above is used, the initial dispensing amount Qp is adjusted at the coating start portion, so that the film thickness profile shape of the coating film C at the coating start portion can also be adjusted to a desired shape. Since it is not necessary to adjust the film thickness profile shape of the film thickness C at the end portion, when adjusting only the film thickness profile shape of the coating film C at the end of application, the initial dispensing amount Qp is adjusted at the application start portion. It is preferred not to use means to do.

  In the first application method and the second application method, the film thickness profile at the end in the application direction can be formed in a desired shape by adjusting the volume of the application liquid supplied from the syringe pump 50 to the die 20. In common.

  The coating liquid to which the present invention can be applied has a viscosity of 1 to 100 mPaS, more preferably 1 to 50 mPaS and is preferably a Newtonian from the viewpoint of coating properties, but can also be applied to a coating liquid having 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.

Example 1
A non-alkali glass substrate having a thickness of 370 × 470 mm and a thickness of 0.7 mm was washed and then coated using the die coater 1. The die has a discharge port length of 370 mm, a discharge port surface length of 0.5 mm, a slit gap of 100 μm, and can form a 370 mm wide coating on the substrate, with a coating speed of 100 mm. / S. A syringe pump 50 having an inner diameter of 16 mm was used. The coating solution was a positive resist used in the production of liquid crystal TFTs, having a solid content concentration of 15% and a viscosity of 5 mPaS. The operating speed of the piston 52 of the syringe pump 50 was set to 1.8 mm / s so that the thickness after vacuum drying was 1.5 μm. First, the substrate application start portion of the substrate where the die was stopped, that is, the substrate edge was brought close to the substrate end with a clearance of 45 μm, and an initial ejection amount Qp of 30 mcc was discharged from the die. In this state, after waiting for 5 seconds, the clearance was set to 100 μm, and after setting the clearance, the piston 52 started to operate at 1.8 mm / s. Then, after the waiting time t = 0.1 seconds from the start of the piston operation, the operation of the stage 6 is also started to perform coating, and the discharge port 34 of the die 20 comes to the position of the 465 mm glass substrate from the substrate end (coating start position). The syringe pump 50 was stopped. Thereafter, the die 20 was pulled up in order to finish the coating when the glass substrate position of 470 mm from the substrate edge came directly under the discharge port 34. After the above application, vacuum drying with an ultimate vacuum of 65 Pa was performed. Then, the film thickness distribution in the coating direction was measured with a light interference type film thickness meter, and the film thickness distribution indicated by the broken line in FIG. 6 was obtained. The film thickness accuracy U at this time was calculated by U = (maximum value−minimum value) / (2 × average value) in a region excluding the end portion of 10 mm, and a value of 3.4% was obtained. When the target is less than 3% and the film thickness distribution shown by the broken line in FIG. 6 is seen, the coating start portion is slightly undershooted. The film thickness distribution indicated by the solid line was obtained. The film thickness accuracy U of this solid line was 2.6%, which reached the target of 3% or less. For reference, the initial delivery amount was returned to 30 mcc, and the coating was performed again with a stop time of 0.11 seconds, to obtain a film thickness distribution indicated by a one-dot chain line in FIG. What was undershooting as shown by the broken line overshoots with the alternate long and short dash line, and the film thickness accuracy U was 3.2%, which was less than 3% of the target.

Example 2
Coating was performed in the same manner as in Example 1 except that a photosensitive blue resist for color filters having a solid content concentration of 20% and a viscosity of 4 mPaS was used as the coating solution. The film thickness distribution in the coating direction was also measured this time. As shown in FIG. 7, the coating end portion overshoots as shown by the broken line, and the film thickness accuracy was U = 4.1% excluding the end portion of 10 mm. . When the stop position of the syringe pump 50 was 465 mm from the substrate end, the total discharge amount of the syringe pump 50 was 1290 mcc, so that the coating was changed to 1280 mcc and reapplied to obtain the film thickness distribution profile shown by the solid line in FIG. It was. In the solid line in FIG. 7, the overshoot at the coating end portion was improved, and the film thickness accuracy U was within an allowable value of 2.9% excluding the end portion of 10 mm. For reference, the stop position of the syringe pump 50 was adjusted so as to be 464 mm from the end of the substrate, and coating was performed again. However, a film thickness profile almost the same as the broken line in FIG. There was almost no difference with 4% excluding 10 mm. This is because the coating speed is 100 mm / s, the difference of 1 mm corresponds to 10 ms, and this difference is buried in the variation of system operation and syringe pump operation, so it is assumed that there is no difference in film thickness profile. It was done.

Example 3
A color filter was manufactured using the die coater 1.
The die had a length in the longitudinal direction of the discharge port of 360 mm, a length in the coating direction of the discharge 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.

  First, after cleaning an alkali-free glass substrate having a thickness of 360 × 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. For the application, the vicinity of the discharge port of the die is wiped with silicon rubber having the same shape as the discharge port, and then the die is brought close to the application start portion of the substrate where the die is stopped with a clearance of 50 μm, and an initial ejection amount of 20 mcc is discharged from the die. . In this state, after waiting for 2 seconds, the clearance is set to 100 μm, the coating liquid corresponding to a wet thickness of 10 μm is fed from the syringe pump, and the movement of the substrate A is started 0.08 seconds after the pump liquid is started. It was. Application was completed by discharging 1667 mcc of application liquid from a syringe pump.

  At this time, the coated black matrix coating solution is a photosensitive material 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. Things were used. The tact time for coating was 30 seconds. The coated substrate was vacuum-dried to reach 65 Pa in 30 seconds for 60 seconds, and further dried on a hot plate at 100 ° C. for 10 minutes. Next, after exposure, development, and peeling, the substrate is heated for 30 minutes on a 260 ° hot plate and cured, and the pitch is 254 μm in the substrate width direction, the pitch is 85 μm in the longitudinal direction of the substrate, and the line width is 20 μm , RGB lattice size is 4800 (substrate longitudinal direction) × 1200 (substrate width direction), diagonal length is 20 inches (305 mm in substrate width direction, 406 mm in substrate longitudinal direction), thickness is 1 μm A black matrix film 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.

  Next, after wet cleaning, the R color coating solution was applied at a thickness of 20 μm, a clearance between the die and the substrate of 100 μm, a total pump discharge amount of 3331 mcc, a discharge speed of 360 mcc / s, and a stage moving speed of 3 m / min. . The coating solution for R color was a photosensitive solution in which acrylic resin was used as a binder, PGMEA was used as a solvent, and pigment red 177 was used as a pigment and mixed at a solid content concentration of 10%, and the viscosity was adjusted to 5 mPaS. The coated substrate was vacuum-dried to reach 65 Pa in 30 seconds for 60 seconds, and further dried on a hot plate at 100 ° C. for 10 minutes. Next, exposure, development, and peeling were performed, leaving an R color coating film having a thickness of 2 μm only in the R pixel portion, and curing was performed by heating on a 260 ° C. hot plate for 30 minutes. Subsequently, on the substrate on which the black matrix and the R color coating film are formed, the coating solution for G color is 20 μm thick, the clearance between the die and the substrate is 100 μm, the total discharge amount of the pump is 3330 mcc, the discharge speed is 360 mcc / s, After applying at a stage moving speed of 3 m / min, vacuum drying was performed for 60 seconds, reaching 65 Pa in 30 seconds, and then further drying for 10 minutes on a hot plate at 100 ° C. Next, exposure, development, and peeling were performed to leave a G-color coating film having a thickness of 2 μm only on the G-color pixel portion, and curing was performed by heating on a 260-degree hot plate for 30 minutes. Furthermore, a B-color coating solution is 20 μm thick, a die-to-substrate clearance of 100 μm, a total pump discharge amount of 3332 mcc, and a discharge speed of 360 mcc / s on a substrate on which a black matrix, R-color, and G-color coating film is formed. Then, coating was performed at a stage moving speed of 3 m / min, and vacuum drying was performed for 60 seconds to reach 65 Pa in 30 seconds, followed by further drying for 10 minutes on a 100 ° C. hot plate. Next, 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 on a 260-degree hot plate for 30 minutes. The G color coating solution is an R color coating solution with 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 and the viscosity was adjusted to 10 mPaS at a solid content concentration of 10%. In any of the R, G, and B color coating solutions, the area near the discharge port of the die is wiped with silicon rubber, and then the die is brought close to the coating start portion of the substrate where the die is stopped with a clearance of 45 μm, and the initial dispensing amount is 25 mcc. Was discharged from the die. In this state, after waiting for 2 seconds, the clearance is set to 100 μm, the coating liquid corresponding to a wet thickness of 20 μm is fed from the syringe pump, and the movement of the substrate A is started 0.13 seconds after the pump feeding is started. It was. Regarding the R color, since it was confirmed that the first coating start portion undershoots, the initial delivery amount was changed to 28 mcc thereafter. 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 variation of ± 3% or less in both the coating direction and the width direction, excluding the end 10 mm.

  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.

  For example, in the manufacturing field of color filters for color liquid crystal displays, array substrates for TFTs, optical filters, printed boards, integrated circuits, semiconductors, etc. Can be used greatly when making adjustments to obtain a more accurate film thickness distribution. Further, it is used for manufacturing display members such as color filters and TFT array substrates that require such a highly accurate film thickness distribution.

FIG. 1 is a schematic front sectional view schematically showing a die coater 1 according to an embodiment of the present invention. FIG. 2 is a time diagram showing the operation status of each operation unit when coating is performed using the die coater 1. FIG. 3 is a film thickness profile diagram of the coating start portion when the initial delivery amount Qp and the standby time t are independently changed. FIG. 4 is a schematic front view showing the operation at the end of application of the die coater 1. FIG. 5 is a film thickness profile diagram at the coating end portion when the pump stop position Xp and the total coating liquid discharge amount Qt are changed independently. FIG. 6 is a diagram showing the film thickness distribution with respect to the substrate position in one embodiment. FIG. 7 is a diagram showing the film thickness distribution with respect to the substrate position in still another embodiment.

Explanation of symbols

1 Die coater 2 Base 4 Guide rail 6 Stage 10 Prop 20 Die (applicator)
22 Front lip 24 Rear lip 26 Manifold 28 Slit 32 Shim 34 Discharge port 36 Discharge port surface 40 Application liquid supply device 42 Supply valve 44 Suction valve 46 Filter 50 Syringe pump 52 Syringe 54 Piston 56 Main body 60 Supply hose 62 Suction hose 64 Tank 66 Application Liquid 68 Compressed air source 70 Vertical lift unit 72 Motor 74 Guide 78 Lift stand 80 Suspension holding stand 90 Wiping unit 92 Wiping head 94 Bracket 96 Slider 98 Drive unit 100 Tray 102 Cart 120 Thickness sensor 122 Support stand 130 Controller 132 Control panel A Substrate (Coating member)
C Coating film

Claims (3)

A state in which the applicator having a discharge port extending in one direction is brought close to the member to be coated and both are stationary, and after discharging the volume Qp of the coating liquid from the applicator, the discharge is stopped and the applicator and the member to be coated are stationary. in by waiting <br/> certain time, after forming the bead between the applicator discharge ports and the coating member, while discharging the coating liquid from the applicator to be coated member, relative with respect to the applicator of the coating member It is a method of starting movement and forming a coating film on a member to be coated, characterized in that the film thickness profile shape of the coating film at the coating start portion is formed into a desired shape by adjusting the volume Qp. How to apply. After the applicator having a discharge port extending in one direction is brought close to the member to be coated and both are stationary, after discharging the coating liquid from the applicator, the discharge is stopped and the applicator and the member to be coated are stationary for a certain period of time. By waiting, after forming a bead between the discharge port of the applicator and the member to be coated, the coating liquid is supplied from the constant capacity pump to the applicator, and the coating liquid is discharged from the applicator to the member to be coated. In a coating method for forming a coating film on a member to be coated by moving the member relative to the coating device, the coating liquid supplied to the coating device by the constant-capacity pump from the start of coating for one coating film formation The coating method is characterized in that the film thickness profile shape of the coating film at the coating end position is formed into a desired shape by adjusting the total volume Qt.   A display member is produced using the coating method according to claim 1 or 2. A method for producing a display member.

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