JP2008212921A - Coating method, plasma display member manufacturing method and coating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated member manufacturing method capable of preventing a substrate from being damaged by stably detecting a protruding part produced by pinching a foreign object between the substrate and a holding means and inhibiting a die from colliding against the substrate, and a coating machine. <P>SOLUTION: A coating method includes the step of coating the coating target surface 9a of the substrate with a coating liquid by the coating means by relatively moving the substrate 9 held by the holding means and the coating means, and further includes the steps of measuring the height profile of the holding means before holding the substrate and the height profile of the coating target surface in the state of holding the substrate by the holding means by using a height measuring means having a plurality of height detection means 4a arranged vertically to the coating direction of the coating means, calculating the thickness profile of the substrate on the basis of the height profile of the coating target surface of the substrate and the height profile of the holding means and making a judgment on whether any foreign object is present by using the result of the calculation and executing trouble-shooting if any trouble is judged present. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating method and a coating apparatus suitable for manufacturing, for example, a plasma display panel, a color filter for a liquid crystal display, an optical filter, a printed wiring board, and an integrated circuit board. In particular, the present invention relates to a method for manufacturing a plasma display member.

  Since a plasma display (hereinafter referred to as PD) can be made larger, thinner and lighter than a cathode ray tube, a television receiver using the plasma display has been widely used. There are various types of PD, but a glass substrate (back plate panel) having cells for red, green, and blue formed in stripes by partition walls, and a glass substrate formed by forming scanning electrodes (front) In general, a plasma display panel (hereinafter referred to as PDP) formed by bonding a face plate panel) is used.

  As a method for forming the partition walls of the back panel of such a PDP, a coating film is formed by applying a partition paste to a single glass substrate, and after drying, a method such as sandblasting or photolithography is used. There is a method of firing in a shape having a stripe-like or lattice-like pattern with a predetermined pitch. Although the thickness of the coating film is relatively thick after firing, about 100 to 200 μm, the uniformity of the thickness affects the characteristics of the PDP, so it is important to uniformly apply the barrier rib paste. There are various coating methods, and one of them is a die coating method using a die coater (for example, Patent Document 1). In this die coating method, the partition paste is ejected from the die and applied to the glass substrate while the die and the glass substrate are relatively moved while the gap between the die and the glass substrate as the base material is kept at a predetermined constant value. . Furthermore, the height of the coated surface of the glass substrate before coating and the height of the coating film surface after coating are measured, and the coating film profile is calculated from the difference in height before and after coating, so that the coating can be applied at a predetermined thickness. There is also a system for determining whether or not there is (for example, Patent Document 2).

  In such a die coating method, when a foreign substance having a shape larger than the gap between the die and the glass substrate is adhered between the glass substrate surface and the glass substrate and the mounting table as a holding means for the glass substrate, Collides with foreign matter or a glass substrate raised by the foreign matter, and the die and the substrate are damaged, and normal coating cannot be performed. Furthermore, the coating is continued without knowing that the die has been damaged due to the collision, and a large amount of defective products are manufactured, and repairing the damaged die also contributes to an increase in manufacturing cost.

  In addition, the die and the glass substrate collide and the glass substrate is damaged, and the damaged material generated at that time may become a new foreign substance and cause defective coating.

  Furthermore, in the die coating method, it is necessary to maintain the gap between the die and the glass substrate with high accuracy, and even if the foreign matter is of a size that does not collide smaller than the gap between the die and the glass substrate, The gap between the die and the glass substrate is locally reduced, and as a result, the coating liquid moves to another part, and the thickness of the coating film is reduced. When the coating film is thinner than a predetermined thickness, it becomes a defective product.

  Such a problem occurs not only in the case of manufacturing a back panel of a PDP, but also in the case of manufacturing a color filter for a liquid crystal display, an optical filter, a printed wiring board, and an integrated circuit board.

  As a method to prevent the collision between the die and foreign matter or between the die and the glass substrate, an interference waveform generated when the effective coating surface is scanned in a non-contact manner by a laser scanning detector before coating and the foreign matter is irradiated with laser light. There is a method of detecting the presence or absence of foreign matter by using (for example, Patent Document 3). However, in this method, in order to increase the detection accuracy, the scanning time becomes long, and there is a problem that a considerable time is required for the foreign matter detection process before coating, or foreign matter is sandwiched between the glass substrate and the mounting table. When the height of the coated surface of the glass substrate gradually changes due to the foreign matter, an interference waveform cannot be obtained, and the protrusion of the glass substrate due to the foreign matter may not be detected. As a solution, there is a method of detecting a foreign object by providing a collision detection sensor on a die (for example, Patent Document 3), but there is a problem that a glass substrate as a product is damaged by the collision sensor.

  Further, there is a device in which a protective means is provided on the die (for example, Patent Document 4). However, since the die is originally protected by allowing collision between the protective means and the glass substrate, the glass substrate is damaged.

There is also a method of detecting foreign matter with a foreign matter detector provided in the longitudinal direction of the die (for example, Patent Documents 5 and 6), but small foreign matter that does not collide between the die and the glass substrate, There was a problem that small ridges that occurred between them could not be detected stably.
JP-A-6-339656 (5th column 18th line to 7th column 25th line, FIG. 1, FIG. 2, FIG. 3) JP-A-2000-197844 (Claim 3, Claim 9, Column 8, Line 29 to Column 10, Line 14, FIG. 1, FIG. 3, FIG. 4) JP 2000-24571 (2nd column 35th line to 43rd line, claim 1, 4th column 12th line to 5th column 36th line) JP-A-2004-283645 (Claim 1, fourth column, 29th line to seventh column, 43rd line, FIG. 4) JP-A-2002-1195 (Claim 3, sixth column, first line to eleventh column, fourth line, FIG. 1) JP-A-2005-85773 (Claim 1, sixth column, 35th line to fourteenth column, 12th line, FIG. 1)

  The object of the present invention is to stably detect a foreign material or a raised portion generated by sandwiching the foreign material between the base material and the holding means without being affected by the state of the base material or the holding means. In addition to preventing the substrate from being damaged by preventing collisions, it is also possible to detect foreign objects that are smaller than the gap between the die and the base material and the raised parts of the base material that are caused by small foreign objects, and remove the detected foreign matter. Accordingly, it is an object of the present invention to provide a coating member manufacturing method and a coating apparatus that eliminate unevenness in coating thickness, suppress the occurrence rate of defective products, and manufacture a high-quality coating member with a short production tact time.

  In order to achieve the above object, the present invention has the following configuration.

  The coating method of the present invention is a coating method in which the coating liquid is applied to the coated surface of the substrate from the coating means while relatively moving the substrate held by the holding means and the coating means. Measurement of the height profile of the holding means before holding the substrate and holding the substrate on the holding means using a height measuring means having a plurality of height detectors arranged in a direction orthogonal to the substrate And measuring the height profile of the coated surface of the substrate in the state, and calculating the thickness profile of the substrate from the height profile of the holding means and the height profile of the coated surface of the substrate, It is characterized by determining the presence or absence of a foreign substance from the calculation result and performing an abnormality process if there is an abnormality.

  Further, in the coating method in which the coating liquid is applied to the coated surface of the base material from the coating means while relatively moving the base material and the coating means held by the holding surface on the holding means, the coating direction of the coating means and Using a height measuring means having a plurality of height detectors arranged in orthogonal directions, measuring the height profile of the held surface of the base material while holding the base material on the holding means; The height profile of the coated surface is measured, and the thickness profile of the substrate is calculated from the height profile of the held surface of the substrate and the height profile of the coated surface of the substrate, and the calculation result It is also characterized in that the presence or absence of foreign matter is determined from the above, and abnormality processing is performed if there is an abnormality.

  Further, after a coating liquid is applied to the coated surface of the substrate by the coating means to form a coated film, a height profile of the coated film is measured using the height measuring means, and the coated substrate is coated. Calculate the thickness profile of the coating film by calculating the surface height profile and the height profile of the coating film on the substrate, and determine whether there is an abnormality in the coating from the calculation result. Preferably it is done.

  Further, while measuring the height profile of the coated surface of the base material using the height measuring means while the base material is held by the holding means, the height profile of the holding means and the coated surface of the base material The thickness profile of the substrate is calculated sequentially from the height profile of the substrate, and the presence or absence of foreign matter is determined from the calculation result, and at the same time, the coating liquid is applied to the coated surface of the substrate by the coating means to form a coating film It is preferable to do.

  Further, while measuring the height profile of the coated surface of the base material using the height measuring means in a state where the base material is held by the holding means, the height profile of the held surface of the base material and the base material The thickness profile of the base material is sequentially calculated from the height profile of the surface to be coated, and at the same time, a coating liquid is applied to the surface to be coated of the base material by the coating means while determining the presence or absence of foreign matter from the calculation result. It is also preferable to form a coating film.

  In addition, it is also preferable to measure the height profile of the coating film using the height measuring unit at the same time while applying the coating liquid to the coated surface of the substrate from the coating unit to form a coating film.

  The plurality of height detectors are preferably arranged at a pitch in the range of 40 to 60 mm.

  The manufacturing method of the member for plasma display of this invention manufactures the member for plasma displays using the above-mentioned coating method.

  The coating apparatus of the present invention includes a holding unit that holds a substrate, a coating unit that coats a coating liquid on a surface to be coated of the substrate, and a moving unit that relatively moves the holding unit and the coating unit. A height measuring unit having a plurality of height detectors arranged in a direction orthogonal to the coating direction, a height profile of the holding unit measured using the height measuring unit, and a substrate to be coated First processing means for calculating the thickness profile of the base material by calculating the surface height profile and determining the presence or absence of foreign matter from the calculated base material thickness profile and performing abnormality processing if there is an abnormality And a first abnormality processing means.

  Further, in a coating apparatus having a holding means for holding the base material on the surface to be held, an application means for applying a coating liquid to the surface to be coated of the base material, and a moving means for relatively moving the holding means and the coating means. A height measuring means having a plurality of height detectors arranged in a direction orthogonal to the coating direction, a height profile of the surface to be held of the base material measured using the height measuring means, and the base material First processing means for calculating the thickness profile of the substrate by calculating the height profile of the surface to be coated, and abnormal processing if there is an abnormality by determining the presence or absence of foreign matter from the calculated thickness profile of the substrate And a first abnormality processing means for performing the above.

  Furthermore, the thickness profile of the coating film is calculated by calculating the height profile of the coating film of the coating liquid on the substrate and the height profile of the coated surface of the substrate measured using the height measuring means. It is preferable to include second calculation means and second abnormality processing means for determining whether or not there is an application abnormality from the calculated coating film thickness profile and performing abnormality processing if there is an abnormality.

  The height detector preferably measures the height in a non-contact manner with a laser beam.

  Moreover, it is also preferable that the height detector measures the height by floating the detection unit on the object to be detected using air and detecting a change in the position of the detection unit.

  The plurality of height detectors are preferably arranged at a pitch in the range of 40 to 60 mm.

  According to the present invention, by calculating the thickness profile of the thickness base material from the height profile of the holding means and the height profile of the surface to be coated of the base material, Protrusions that occur between them are detected to avoid collision between the coating means and the base material, or the coating means and the foreign matter, so that the production operation time caused by removing the damaged base material, cleaning, and die replacement Can be eliminated. In addition, secondary defects such as a coating defect caused by scattered scattered objects and a new base material raised by biting damaged scattered objects can be avoided.

  In addition, since the thickness profile of the base material can be calculated from the height profile of the base surface to be held and the height profile of the base surface to be coated, it is not affected by the base material holding surface condition of the holding means. Therefore, it is possible to detect the presence / absence of a foreign substance with stability and high accuracy.

  In this way, the presence or absence of foreign matter can be detected with high accuracy, and foreign matter can be eliminated, so that a foreign matter smaller than the gap between the base material and the die or a small amount of foreign matter that is sandwiched between the base material and the holding means is generated. It is possible to eliminate coating unevenness caused by the protrusion of the substrate.

  Furthermore, by arranging a plurality of height detectors at appropriate intervals, it is possible to detect the presence or absence of foreign matter sandwiched between the holding means and the substrate over the entire surface of the substrate.

  Furthermore, by performing application while determining the presence or absence of foreign matter immediately before application, the time for determining the presence or absence of foreign matter can be reduced. Moreover, since the height of the coating film surface after application | coating can also be measured performing application | coating, the measurement time of the coating film surface height after application | coating can be reduced, and production tact time can be shortened.

  Furthermore, since the above excellent coating method is used for the production of the plasma display member, a large amount of high-quality plasma display members can be stably produced with high productivity.

FIG. 1 is a schematic front view of a die coater 11 which is a coating apparatus according to an embodiment of the present invention, FIG. 2 is a schematic side view of a height measuring means 4, and FIG. 3 is a plan view of the die coater 11.
As shown in FIG. 1, the die coater 11 includes a mounting table 1 that is a holding unit that holds a substrate 9 corresponding to a base material, a coating unit 2, a moving unit 3 that relatively moves the mounting table 1 and the coating unit 2, and a height. It has a measuring means 4, a data processor 5 which is a computing means, a controller 7, and a coating liquid supply means 8. In FIG. 1, the moving means 3 includes a gantry 3a, a nut 3b, a ball screw 3c, a servo motor 3d, and a guide 3e. A single substrate 9 is sucked and held on the upper surface 1a of the mounting table 1 as a holding means on the gantry 3a. The mounting table 1 is supported by a guide 3e and screwed into a ball screw 3c via a nut 3b. The position A is guided by the guide 3e as the servo motor 3d is rotated forward and backward, and is indicated by a solid line. It can reciprocate between position B shown with a dashed-two dotted line. This reciprocation is controlled by the controller 7. The controller 7 has not only a control function for performing normal application as described above, but also functions as a first abnormality processing unit and a second abnormality processing unit as described later. The coating liquid supply means 8 includes a coating liquid tank 8a, a coating liquid pump 8b that sends out the coating liquid in the coating liquid tank 8a, a pipe 8c that connects the coating liquid tank 8a and the coating liquid pump 8b, and a coating liquid. A pump 8b and a pipe 8d for connecting the coating means 2 are provided. The coating liquid tank 8a is preferably a sealed tank, and the inside is preferably pressurized to a pressure of about 0.02 to 1 MPa with air or an inert gas (for example, nitrogen gas). The coating liquid pump 8b is preferably a syringe pump that pushes out the liquid in the syringe with a piston. However, the coating liquid pump 8b may be a constant capacity pump such as a gear pump or a diaphragm pump, or may be pumped by air pressure. Good. The coating liquid pump 8 b operates based on a signal from the controller 7.

  The application means 2 includes a support column 2a attached to the gantry 3a of the moving means 3, a guide 2b attached to the support column 2a, a holder 2c guided by the guide 2b, and a coating device attached to the holder 2c. A slit die 2d connected to the pipe 8d of the liquid supply means 8; A ball screw 2f driven by a servo motor 2e is screwed to the holder 2c, and when the servo motor 2e is rotated forward and backward based on a signal from the controller 7, the holder 2c is guided by the guide 2b and moved up and down. Accordingly, the slit die 2d moves up and down. That is, the gap between the slit die 2d and the substrate 9 can be arbitrarily changed as the slit die 2d moves up and down.

  In the coating method of the present invention, coating is performed by extruding the coating liquid onto the substrate 9 from the coating means 2 while relatively moving the substrate 9 and the coating means 2 held by the mounting table 1 as the holding means. I do.

  In the die coater 11 shown in FIG. 1, the application unit 2 is fixed and the mounting table 1 holding the substrate 9 on the upper surface 1a is moved in the horizontal direction to move both relative to each other. Both can be moved relatively by fixing the mounting table 1 and moving the coating means 2 in the horizontal direction. Further, both the mounting table 1 and the coating means 2 may be moved in the horizontal direction.

  The height measuring unit 4 includes a height profile of the mounting table 1 serving as a holding unit, that is, a height profile of the upper surface 1a, and a substrate 9 before coating that is held on the upper surface 1a of the mounting table 1 by a held surface 9b. The height detector 4a for measuring the height profile of the coated surface 9a and the height profile of the coating film of the coating liquid on the substrate 9 after coating is attached to the height detector mounting column 4b. ing. The coated surface 9a of the substrate 9 is the surface on which the coating liquid is applied by the die coater 11 on the substrate 9, and the retained surface 9b is the surface opposite to the coated surface 9a. It is defined as a surface that is in close contact with the upper surface 1a of the surface.

  Furthermore, the height profile data obtained by the height detector 4a is collected, stored, and calculated, and functions as a first calculation means and a second calculation means to be described later, and whether there is no foreign object from the measured data. A data processor 5 for discrimination and a display 6 for displaying the measured height profile are provided.

  In the coating method of the present invention, before the substrate 9 as a base material is placed, first, the height profile of the placing table 1 as a holding means is measured using the height measuring means 4. Next, the substrate 9 is carried onto the mounting table 1 and held by suction. Thereafter, the height profile of the coated surface 9a of the substrate 9 held by the held surface 9b on the upper surface 1a on the mounting table 1 is measured using the height measuring means 4, and mounted using the data processor 5. The thickness profile of the substrate 9 is calculated from the height profile of the mounting table 1 and the height profile of the coated surface 9a of the substrate 9, and the presence or absence of foreign matter is determined from the calculation result. At this time, the data processor 5 functions as the first calculation means described above. The presence / absence of a foreign substance is determined from the result thus calculated, and if there is an abnormality, an abnormality process is performed. Specifically, when it is determined that there is a foreign substance as a result of determination using the data processor 5, a signal is sent to the controller 7, and the coating operation is immediately stopped. At this time, the controller 7 functions as the first abnormality processing means described above.

  A plurality of height detectors 4a are arranged on the height detector mounting column 4b in the coating width direction of the substrate 9, but as shown in FIG. 2, the height detector 4a has a full width in the coating width direction of the substrate. It is preferable that it is arrange | positioned over.

  Then, by moving the mounting table 1 in the coating direction, the upper surface 1a of the mounting table 1 passing directly under the height detector 4a, the coated surface 9a of the substrate 9 attracted and held on the mounting table 1, and the substrate 9 The height profile of each coating film can be obtained over the coating direction.

  The height detector 4a is preferably a non-contact type such as a laser type, a capacitance type or an ultrasonic type, and particularly preferably a laser focus type which is not easily affected by disturbance. With the laser focus type, the objective lens through which the reflected light of the laser passes can be reciprocated at high speed, and the distance from the object to be measured can be known from the position of the objective lens when the reflected light is received pinpoint. is there.

Instead of the height profile of the mounting table 1, that is, the height profile of the upper surface 1a, the height detector 4a measures the height profile of the held surface 9b of the substrate 9 that is in close contact with the upper surface 1a. Then, the thickness profile of the substrate 9 may be calculated from the height profile of the held surface 9b and the height profile of the coated surface 9a, and the presence or absence of foreign matter may be determined from the calculation result. When measuring the height profile of the mounting table 1, if there are suction holes or suction grooves for sucking the substrate 9 on the measurement line,
The reflected light of the laser beam is scattered, the measurement becomes unstable, and in the worst case, the measurement becomes impossible. If the height profile of the supported surface 9b of the substrate 9 is measured instead of the height profile of the mounting table 1, it can be measured stably at any position without being affected by the state of the upper surface 1a of the mounting table 1. More preferable. Since the height profile of the held surface 9b of the substrate 9 is a substitute for the height profile of the mounting table 1, foreign matter such as dust on the upper surface 1a of the mounting table 1 and dust on the held surface 9b of the substrate 9 are obtained. What is measured in a state in which the substrate 9 is sucked and held on the mounting table 1 in a state in which foreign substances such as these are completely removed is used for the subsequent calculation of the thickness profile of the substrate 9. Accordingly, when there is a foreign object between the substrate 9 and the mounting table 1, the thickness profile of the substrate 9 shows an abnormal value, so that the foreign object can be detected.

  The height profile of the held surface 9b of the substrate 9 is measured by irradiating the held surface 9b with the laser beam of the height detector 4a through the coated surface 9a of the substrate 9 and measuring the reflected light. Therefore, it is preferable that the substrate 9 is transparent or translucent so that the laser beam reaches the held surface 9b of the substrate 9 and the reflected light from the held surface 9b can be received by the height detector 4a.

  If there is no change over time in the inclination and undulation of the mounting table 1, the inclination and undulation of the guide 3e for moving the mounting table 1, and the measurement accuracy of the height detector 4a, the obtained height profile is the same and there is no change. In addition, the measurement of the height profile of the mounting table 1 and the height profile of the held surface 9b of the substrate 9 may be performed only once during preparatory work before coating, and moreover, for example, once a month or six months, It may be measured periodically.

  When the measurement of the height profile of the coating film is not performed, the height detector 4a blows air from the detection unit of the contact-type displacement meter, thereby placing the substrate 1 on the mounting table 1 or the substrate to be detected. 9 may be used that floats the detection unit on 9 and detects the position change of the detection unit to measure the height.

  Next, the pitch at which the height detector 4a is arranged will be described.

  When a foreign object is sandwiched between the substrate 9 and the mounting table 1, the substrate 9 rises over the substrate raised portion length L2 that is equal to or larger than the sphere equivalent diameter d of the foreign object 10, as shown in FIG. Accordingly, if the height detectors 4a are arranged at a pitch less than the substrate raised portion length L2, it is possible to detect the raised portion due to the foreign matter anywhere in the application width direction of the substrate 9, so that the substrate on the mounting table 1 is applied in the application direction. By moving to, foreign matter sandwiched between the substrate 9 and the mounting table 1 can be detected over the entire surface of the substrate. Further, when the length of the measurement range of the height detector 4a is L1, the arrangement pitch of the height detectors 4a may be less than (L2 + L1), and the substrate is spread over the entire surface of the substrate with a smaller number of height detectors 4a. The presence or absence of a foreign object sandwiched between 9 and the mounting table 1 can be detected.

  FIG. 15 is a graph showing the results of a model test in which beads are sandwiched between the substrate 9 and the mounting table 1. In FIG. 15, when a glass substrate having a thickness of 2 mm and 3 mm is used as the substrate 9, the sphere equivalent diameter d of the foreign material 10, and when the foreign material 10 is sandwiched between the substrate 9 and the mounting table 1, The result of having actually measured the relationship of the board | substrate protruding part length L2 to perform is shown.

  Here, as a foreign material model, glass beads having diameters of 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, and 50 μm were used, and each glass bead was placed between each glass substrate having a thickness of 2 mm and 3 mm and the mounting table. A glass substrate is adsorbed and held between the glass beads, and the upper portion of the glass beads is scanned by a laser focus type height detector to measure the height change of the raised portions at intervals of 0.1 mm.

  As shown in FIG. 2, the substrate raised portion length L2 refers to the length of a range of a mountain portion where the height continuously rises 0.1 μm or more from a flat portion.

  From FIG. 15, for example, when a glass substrate has a thickness of 2 mm and a foreign object having a sphere equivalent diameter d of 10 μm is interposed between the glass substrate and the mounting table, the glass substrate extends over a substrate raised portion length L2 of 50 mm. However, when the thickness of the substrate is 3 mm, the glass substrate rises over the substrate raised portion length L2 of 65 mm even if the same foreign matter has a sphere equivalent diameter d of 10 μm. In addition, when the equivalent sphere diameter d of the foreign matter is in the range of 5 μm to 10 μm, when the equivalent sphere diameter d of the foreign matter is increased by 5 μm, the substrate raised portion length L2 is increased by 20 mm, but the equivalent sphere diameter d of the foreign matter is in the range of 10 μm to 60 μm. Then, while the size d of the foreign matter is increased by 50 μm, the substrate raised portion length L2 is increased by 20 mm.

  From the above results, when the equivalent spherical diameter d of the foreign material is 10 μm or more, when a glass substrate having a thickness of 2 mm or more is used, the length L2 of the substrate protruding portion when the foreign material is sandwiched between the loading table and the glass substrate is 50 mm. As described above, if the height detectors are arranged in the coating width direction at a pitch corresponding to the height detectors, the entire surface of the substrate can be detected relatively easily.

  The arrangement pitch of the height detectors for detecting the raised portions over the entire surface of the glass substrate is less than (L2 + L1) as described above. Here, for example, if a laser focus type height detector is used, the length L1 of the measurement range is equal to the measurement spot diameter, so it is about several μm, and the length L1 can be regarded as almost zero. . Therefore, in order to detect a foreign matter of 50 μm or more sandwiched between a glass substrate having a thickness of 2 mm and a mounting table using a laser focus type height detector, the height detector is L2 + L1 = 70 + 0. = What is necessary is just to arrange | position with the pitch of less than 70 mm. When a height detector provided with a slit laser beam having a length of 10 mm and a light receiving element having a length corresponding to the slit laser beam is used, the length L1 of the measurement range of the height detector is 10 mm. Therefore, in order to detect foreign matter having a spherical equivalent diameter of 50 μm or more sandwiched between a glass substrate having a thickness of 2 mm and a mounting table over the entire surface of the glass substrate, the height detector is set at a pitch of less than L2 + L1 = 70 + 10 = 80 mm. What is necessary is just to arrange.

  In order to manufacture a plasma display member, it is necessary to detect a foreign substance having a size of about 10 μm to 40 μm with a glass substrate having a thickness of about 2 mm. Therefore, the pitch for arranging the height detector is preferably about 40 mm to 50 mm. . If the pitch is longer than 50 mm, it is impossible to stably detect the foreign matter having a spherical equivalent diameter d of about 10 μm over the entire surface of the glass substrate, and if the pitch is shorter than 40 mm, the required height detector is disposed. The number increases and the equipment cost increases.

  When using a glass substrate with a significantly different thickness or a base material of a different material, the sphere equivalent diameter of the foreign material and the raised portion of the base material when the foreign material is sandwiched between the base material and the holding means as described above. It is important to measure the length relationship. This makes it possible to appropriately determine the pitch at which the height detector is disposed.

  Now, the height profile of the mounting table 1 by the height measuring means 4 described above, the height profile of the surface 9a to be coated of the substrate 9 before being applied and held on the upper surface 1a of the mounting table 1, and the coating liquid after coating The height profile of the coating film surface can be measured by moving the mounting table 1 with respect to the substrate 9 in the coating direction (the moving direction of the mounting table 1 in FIG. 1). The operation of the height measuring means 4 is controlled by the controller 7 such as the start and end of measurement by, and the start and end of data collection by the data processor 5. The collected data is stored in the data processor 5 and further subjected to arithmetic processing and the like, and the processing result is displayed on the display 6.

  As described above, the controller 7 controls the reciprocation of the mounting table 1 in the moving means 3, controls the coating liquid pump 8b in the coating liquid supply means 8, and controls the gap between the slit die 2d and the substrate 9 in the coating means 2. Then, control of data collection start and end by the data processor 5 in the height measuring means 4, and control of continuing or stopping the coating operation by discriminating foreign matter in the height measuring means 4, and further, slit die 2d Control of starting and stopping of coating liquid supply by the coating liquid supply means 8 is also performed.

  In the coating method of the present invention, the coating film is coated on the surface 9a of the substrate 9 by the coating means 2 to form a coating film, and then the height profile of the coating film is measured using the height measuring means 4. The thickness profile of the coating film is calculated by calculating the height profile of the coated surface 9a of the base material 9 and the height profile of the coating film on the base material. It is preferable to perform abnormality processing if there is an abnormality. At this time, the data processor 5 functions as second arithmetic means, and the controller 7 functions as second abnormality processing means.

  Now, in the coating method of the present invention using the die coater 11 described above, a first step of measuring the height profile of the mounting table 1 (hereinafter referred to as step 1), the height profile of the surface 9a to be coated of the substrate 9 is obtained. Second step to be measured (hereinafter referred to as “step 2”), third step (hereinafter referred to as “step 3”) for applying the coating liquid to the substrate 9, and if necessary, the height of the coating film surface of the coating liquid on the substrate 9 Four (steps 1 to 3 and 5) or five (step) of a fourth step (hereinafter referred to as step 4) for measuring the profile and a fifth step (hereinafter referred to as step 5) for carrying out the coated substrate 9 1-5). Next, the preferable aspect of the coating method of this invention is demonstrated in detail for every process, referring FIGS.

  In addition, the height detector 4a is arrange | positioned on each line shown by the height profile measurement line Pmi (i = 1-n) in FIG. 3, and the mounting base 1 and the mounting base are moved by the movement of the mounting base 1 in the application direction. The height of the substrate 9 on 1 and the surface of the coating film can be measured. A plurality of lines indicated by height profile measurement lines Pmi (i = 1 to n) are arranged so as to cover the entire surface of the substrate 9 with a pitch interval less than the distance indicated by L2 + L1 in FIG. 2, and on each line. The measurement position is preset.

Step 1: Measurement of Height Profile of Mounting Table 1 In this step, the height profile of the mounting table 1 is measured.

  First, the servo motor 3d of the moving means 3 is driven and the ball screw 3c is rotated to move the mounting table 1 on which the substrate 9 is not mounted from the position A to the position B at a constant speed in the coating direction. When the mounting table 1 passes under the height detector 4a, each height detector 4a has a height profile of the mounting table 1 in the coating direction on the line of the height profile measurement line Pmi (i = 1 to n). Shm0i (i = 1 to n) is measured. In addition, the position and number on the mounting table 1 in the application direction for measuring the height are given in advance.

  The height profile Shm0i (i = 1 to n) of the mounting table 1 measured on the line indicated by Pmi (i = 1 to n) is collected and stored in the data processor 5 and displayed on the display 6 as a graph.

  An example of the height profile Shm0i of the mounting table 1 is shown in FIG. The height profile rises to the right and has undulations. This is because the inclination and the undulation of the mounting table 1 and the inclination and the undulation of the guide 3e for moving the mounting table 1 are measured in a state of being superimposed on the original height profile.

  When the suction hole for sucking and holding the substrate 9 on the mounting table 1 is on the height profile measurement line Pmi (i = 1 to n), the height value is greatly disturbed or cannot be measured at the suction hole portion. Therefore, if there is data that changes abruptly more than a predetermined value in the height profile Shm0i (i = 1 to n) or a portion that cannot be measured, the height profile before and after that may be replaced. preferable.

  Further, the substrate 9 is sucked and held by the held surface 9b on the upper surface 1a of the mounting table 1 in a state where the dust adhering to the upper surface 1a of the mounting table 1 and the dust adhering to the substrate 9 are completely removed. Then, the laser beam of the height detector 4a passes through the coated surface 9a of the substrate 9 and irradiates the held surface 9b, the height profile of the held surface 9b is measured from the reflected light, and the mounting table 1 You may use as a height profile of the upper surface 1a.

In step 1, if there is no change over time in the inclination or undulation of the mounting table 1, the inclination or undulation of the guide 3e for moving the mounting table 1, and the measurement accuracy of the height detector 4a, the obtained height profile is the same. Therefore, the measurement of the height profile of the mounting table 1 and the height profile of the held surface 9b of the substrate 9 may be performed only once during the preparatory work before coating, and for example, for one month or so. You may measure regularly once every six months. Step 2: Measurement of the height profile of the coated surface 9a of the substrate 9 In this step, the same position where the height profile of the coated surface 9a of the substrate 9 held by suction at a predetermined position of the mounting table 1 is measured in Step 1. Measure with Further, the thickness profile of the substrate 9 is calculated from the height profile of the mounting table 1 and the height profile of the coated surface 9a of the substrate 9, and the presence / absence of foreign matter is determined from the calculation result. .

  First, the substrate 9 is placed at a predetermined position on the mounting table 1, and the substrate 9 is sucked and held on the mounting table 1 by suction from a suction hole (not shown).

  Subsequently, the servo motor 3d of the moving means 3 is driven and the ball screw 3c is rotated to move the mounting table 1 from the position A to the position B in the coating direction at a constant speed. When the substrate 9 passes under the height detector 4a, each height detector 4a is applied at the same position measured in step 1 on the height profile measurement line Pmi (i = 1 to n) at the coating direction. The height profile Shm1i (i = 1 to n) of the coated surface 9a of the substrate 9 is measured. In addition, the same position and number measured at the step 1 are given in advance as the position and the number on the mounting table 1 in the application direction for measuring the height.

  The height profile Shm1i (i = 1 to n) of the coated surface 9a of the substrate 9 measured at the same position as in step 1 on the line indicated by the height profile measurement line Pmi (i = 1 to n) is a data processor. 5 is collected and stored, and displayed on the display 6 as a graph.

  An example of the height profile Shm1i of the coated surface 9a of the substrate 9 is shown in FIG. As with the height profile Shm0i of the mounting table 1 shown in FIG. 4, the height profile of the coated surface 9a of the substrate 9 shown in FIG. This is because the inclination and the undulation of the mounting table 1 and the inclination and the undulation of the guide 3e for moving the mounting table 1 are measured in a state of being superimposed on the original height profile.

  Next, the data processor 5 performs a calculation process of subtracting the height profile Shm0i (i = 1 to n) of the mounting table 1 from the height profile Shm1i (i = 1 to n) of the coated surface 9a of the substrate 9. Then, the substrate thickness profile Thm1i (i = 1 to n) is calculated.

  The result of each arithmetic processing is displayed as a graph on the display 6. An example of the substrate thickness profile Thm1i is shown in FIG. Since the tilt and undulation of the mounting table 1 included in the measurement of the height of the coated surface 1a of the mounting table 1 and the substrate 9 and the tilt and undulation of the guide 3e for moving the mounting table 1 are excluded by subtraction, FIG. Only the true substrate thickness profile is shown.

  4, 5, and 6 are cases where there is no foreign matter on the front and back surfaces of the substrate 9, the case where there is a foreign matter will be described with reference to FIGS. 7 to 9.

  FIG. 7 is a view showing a state in which the foreign material 10 is sandwiched between the substrate 9 and the mounting table 1. An example of the height profile Shm1i of the coated surface 9a of the substrate 9 in the state of FIG. 7 is shown in FIG. In FIG. 8, although a protrusion due to a foreign object is included, it cannot be determined at first glance whether it is due to a foreign object or due to the undulation of the mounting table 1. FIG. 9 shows an example of the thickness profile of the substrate 9 in the state of FIG. This is obtained by subtracting the height profile Shm0i of the mounting table 1 shown in FIG. 4 from the height profile Shm1i of the coated surface 9a of the substrate 9 shown in FIG.

  In FIG. 9, since the abnormal thickness portion a <b> 1 exists, it can be seen that the substrate 9 is raised due to the foreign material 10 being sandwiched. Thus, the presence / absence of foreign matter can be clearly determined by the thickness profile Thm1i of the substrate 9. The data processor 5 sets a threshold level as indicated by a one-dot chain line in FIG. 9 with respect to the standard thickness of the substrate, and if there is data exceeding the threshold level, it is determined that there is a foreign substance, and the controller 7 Send an abnormal signal to After receiving the abnormality signal, the controller 7 issues an abnormality alarm and stops the coated substrate manufacturing process. The operator removes the foreign matter after confirming the abnormality alarm. Thereafter, the controller 7 receives a restart instruction from the operator, and the manufacturing process is resumed.

  Since the manufacturing process is automatically stopped when a foreign object is detected, the slit die 2d does not collide with the substrate 9 raised by the foreign object or the foreign object. As a result, a defective product is manufactured or the manufacturing process is stopped. Thus, there is no work such as replacement with a spare slit die, and there is no increase in manufacturing cost or reduction in operating rate.

Step 3: Application of coating liquid to substrate 9 In the coating method of the present invention, the coating liquid is applied while relatively moving the substrate 9 and the coating means 2 held by the mounting table 1 as the holding means. The coating is performed by extruding onto the substrate 9 from the means 2, and it is preferable to perform the coating while controlling the gap between the substrate 9 and the slit die 2d based on the height profile of the surface 9a to be coated. . The method will be described below.

  First, based on the height profile Shm1i of the coated surface 9a of the substrate 9 obtained in step 2, the die coater 11 is set so that the gap between the slit die 2d of the coating means 2 and the substrate 9 becomes a desired constant value. The servo motor 2e is driven by a command from the controller 7, and the slit die 2d is lowered.

  Next, the mounting table 1 of the moving means 3 is moved at a constant speed from the position A to the position B in FIG. When the controller 7 detects that the application start site of the substrate 9 has reached just below the discharge port of the slit die 2d, it instructs the coating liquid pump 8b of the coating liquid supply means 8 to start supplying the coating liquid. As a result, the coating liquid is discharged from the slit die 2d, and application to the substrate 9 is started. The supply amount of the coating liquid to the slit die 2 d by the coating liquid pump 8 b is determined according to the target film thickness set in the controller 7.

  When the application end portion of the substrate 9 reaches just below the discharge port of the slit die 2d, a stop command is sent from the controller 7 to the coating liquid pump 8b, and the discharge of the coating liquid from the slit die 2d is stopped and the slit die 2d. Is raised. From the start to the end of coating, based on the height profile Shm1i of the surface 9a to be coated of the substrate 9, the gap between the slit die 2d of the coating means 2 and the substrate 9 is always a desired constant value. The servo motor 2e is preferably driven by a command from the controller 7 of the die coater 11 to control the height of the slit die 2d.

  The mounting table 1 moves back to the position A after moving to the position B.

Step 4: Measurement of the height profile of the coating film of the coating liquid applied to the substrate 9 In this step, the height profile of the coating film of the coating liquid applied to the substrate 9 is measured, and the thickness profile of the coating film is determined. calculate. Also, the presence or absence of application abnormality is determined from the calculation result.

  First, the servo motor 3d of the moving means 3 is driven and the ball screw 3c is rotated to move the mounting table 1 from the position A to the position B at a constant speed in the coating direction. When the substrate 9 passes under the height detector 4a, the substrate in the coating direction at the same position measured in step 1 on the height profile measurement line Pmi (i = 1 to n) by the height detector 4a. 9, the height profile Shm2i (i = 1 to n) of the coating film surface is measured. In addition, the same position and number measured at the step 1 are given in advance as the position and the number on the mounting table 1 in the application direction for measuring the height.

  The height profile Shm2i (i = 1 to n) of the coating film surface of the substrate 9 measured at the same position as in step 1 on the line indicated by the height profile measurement line Pmi (i = 1 to n) is the data processor 5. Collected and memorized.

  Next, the data processor 5 subtracts the height profile Shm1i (i = 1 to n) of the coated surface 9a of the substrate 9 from the height profile Shm2i (i = 1 to n) of the coating film surface of the substrate 9 in the coating direction. An arithmetic process is performed to calculate a thickness profile Thm2i (i = 1 to n) of the coating film.

  The calculated coating film thickness profile Thm2i (i = 1 to n) is displayed as a graph on the display 6. An example of the thickness profile Thm2i of the coating film is shown in FIG.

  A threshold level is set for the set film thickness as shown by the one-dot chain line in FIG. 10, and if there is a portion exceeding the threshold level, the data processor 5 determines that the film thickness is abnormal, and sends it to the controller 7. Send an abnormal signal. After receiving the abnormality signal, the controller 7 issues an abnormality alarm and stops the coated substrate manufacturing process.

  After the operator recognizes the film thickness abnormality by the abnormality alarm, the cause of the film thickness abnormality is the abnormality of the slit die 2d for the next action, or the foreign matter on the substrate 9 or between the substrate 9 and the mounting table 1 Investigate whether it is because there is. Hereinafter, an example of the determination method will be described.

  FIG. 11 is a diagram showing another example of the thickness profile Thm2i of the coating film. Here, the thickness of the coating film has a dent in the abnormal thickness portion a2, which is below the threshold level, but the dent was caused by the corresponding portion of the slit die 2d being clogged and the coating liquid not being discharged. It is difficult to determine whether this is caused by foreign matter on the substrate 9 or when the portion of the substrate 9 is raised with the foreign matter sandwiched between the substrate 9 and the mounting table 1.

  Therefore, the thickness profile of the substrate 9 in the same height profile measurement line Pmi is examined. FIG. 12 shows an example of the substrate thickness profile Thm1i in the same height profile measurement line Pmi as in FIG. In FIG. 12, a raised portion a3 is present at a position corresponding to the abnormal thickness portion a2 where the dent was present in FIG. Although the thickness of the raised portion a3 is within the threshold level indicated by the one-dot chain line, it can be seen that there is a foreign object between the mounting table 1 and the substrate 9, and the substrate 9 is raised. Accordingly, since the dent in the film thickness at the portion a2 in FIG. 11 has a small foreign object sandwiched between the substrate 9 and the mounting table 1 at the portion a2, the substrate 9 rises at the portion a2 and the slit die 2d. It can be seen that this occurred because the gap between the substrates 9 became narrow and the application of the coating liquid was hindered. If the operator can determine that the cause of the foreign matter is the above result, the operator removes the foreign matter or cleans the mounting table 1.

  FIG. 13 shows another example of the thickness profile Thm1i of the substrate 9 in the same height profile measurement line Pmi as in FIG. 11, but when the substrate thickness is flat as described above, the substrate 9 and the substrate 9 are mounted. Since the foreign matter sandwiched between the pedestals 1 is not the cause of the dent of the abnormal part a2, inspection such as dirt and clogging in the slit of the slit die 2d is performed.

  11 is an example in which the threshold level is exceeded, but the film thickness can be reduced by the method of the present invention when the film thickness profile has a small depression even within the threshold level range. By identifying the cause of the dent and removing foreign matter smaller than the gap between the substrate 9 and the slit die 2d or cleaning the slit die 2d, it becomes possible to reduce coating unevenness and improve quality and yield. High productivity.

Step 5: Unloading the coated substrate 9 In this step, the substrate 9 after the coating film thickness measurement is unloaded to the next step.
When the data processor 5 determines that there is no abnormality in the film thickness, the suction of the sucked and held substrate 9 is released, and it is downstream of the mounting table 1 at the position B by a robot hand (not shown). It is carried out to the process. If the data processor 5 determines that there is an abnormality exceeding the quality limit in the film thickness, the controller 7 sends a command to a robot hand (not shown), and the robot hand carries the substrate as a defective product to another location. To do. When the unloading of the substrate 9 is completed, the mounting table 1 is moved back from the position B to the position A.

  In the present embodiment, an example is shown in which each step is sequentially performed. However, in the die coater 11 shown in FIGS. 1 and 3, the height profile of the surface 9 a to be coated 9 in the step 2 is measured, and the step 3 is performed. Since the coating liquid can be applied to the substrate 9 during the same movement from the position A to the position B of the mounting table 1, the production tact time can be shortened by performing the steps 2 and 3 simultaneously. That is, when the substrate 9 placed on the placement table 1 is moved from the position A to the position B while being applied by the slit die 2d, the substrate 9 before being applied when passing through the height detector 4a. While measuring the height profile of the coating surface 9a, the height profile of the mounting table 1 at the same measurement position stored in advance in step 1, or the height of the held surface 9b of the substrate 9 at the same measurement position. The calculation of subtracting the profile is sequentially performed, and when it is determined that there is a foreign substance, the application operation may be stopped immediately. Since the height profile of the coated surface 9a of the substrate 9 is measured prior to the coating operation, foreign matter detection can be performed on all coated substrates. If the coating is stable, if the measurement of the height profile of the coating film surface of the coating liquid applied to the substrate 9 in step 4 is performed once for several sheets, the production tact time is further reduced. Can be shortened.

  In the above-described embodiment, an example is shown in which the substrate 9 is loaded when the mounting table 1 is at the position A, and after passing through each process, the substrate 9 is discharged when the mounting table 1 is at the position B. When the mounting table 1 on which the substrate is mounted is moved from the position A to the position B while being applied by the slit die 2d, and then moved from the position B to the position A, the coating film of the coating liquid applied to the substrate 9 which is step 4 Even when the surface height profile is measured and the substrate is discharged at the position A, the production tact time can be shortened.

  Further, with the die coater 11 shown in FIGS. 1 and 3, the height profile of the coated surface 9a of the substrate 9 which is step 2 is measured when the mounting table 1 is moved from the position A to the position B. While moving the mounting table 1 from the position B to the position A, the coating liquid is applied to the substrate 9 which is step 3, and the height profile of the coating film surface of the coating liquid applied to the substrate 9 which is step 4 is measured. Even if it is carried out simultaneously, the production tact time can be shortened. In this case, the substrate may be carried in and out while the mounting table 1 is at the position A.

  Further, in the present embodiment, an example is shown in which the threshold level is set based on the standard thickness of the substrate used for coating in order to detect foreign matter, but the height profile of the surface 9a to be coated of the substrate 9 is shown. The average value of Shm1i (i = 1 to n) may be set as a reference.

  In this embodiment, an example in which the threshold level is set based on the film thickness set for detecting an abnormality in the film thickness is shown, but the average of the film thickness profiles Thm2i (i = 1 to n) is shown. The value may be used as a reference.

  In the above embodiment, the viscosity of the coating solution is preferably in the range of 3000 to 30000 mPa · sec, and the coating speed is preferably in the range of 1 to 10 m / min. The measurement pitch on the height profile measurement line Pmi is preferably 0.05 mm to 10 mm, more preferably 0.1 mm to 1 mm. The measurement speed of the height profile is preferably performed within a range of 1 m / min to 30 m / min. When the measurement pitch is made shorter than the above range or the measurement speed is made slower than the above range, the measurement time is remarkably increased, the processing time for one sheet is increased, and the production efficiency is remarkably lowered. Conversely, if the measurement pitch is made longer than the above range or the measurement speed is made faster than the above range, small foreign matter or coating unevenness may not be detected.

  As described above, the intervals at which the height detectors 4a are arranged may be arranged at intervals of 50 mm, for example, when detecting a foreign substance of 10 μm or more on a glass substrate having a thickness of 2 mm based on the characteristics of FIG.

  In the above embodiment, the application to the single-wafer coated member such as the glass substrate has been described. However, when applying to a member such as a film, a metal sheet or a metal foil which is a continuous member using a roll as a holding means. By applying the present invention, the height profile of a roll, the height profile of a continuous substrate such as a film, and the coating film surface height profile can be measured to detect foreign matter and coating thickness unevenness due to the foreign matter. .

  First, as a pre-process, a photosensitive silver paste is screen-printed to a thickness of 5 μm on a soda glass substrate having a width (substrate width direction) of 570 mm × length (application direction) of 970 mm × thickness of 2 mm, and then a photomask The film was exposed to light and subjected to development and baking steps to form 3072 silver electrodes in a stripe shape with a pitch of 300 μm. A glass paste made of glass and a binder was screen-printed on the electrode and then fired to form a dielectric layer having a thickness of 10 μm.

  Next, an article having a width (substrate width direction) of 600 mm × length (application direction) of 1000 mm was used for the mounting table 1 of the substrate 9 on which the partition wall glass paste was applied by the die coater 11 of FIG. FIG. 14 is a plan view showing the arrangement of the height detection means 4a in the embodiment. In order to measure the height profile, as shown in FIG. 14, the height profile measurement line Pm1 is a line extending in the coating direction at a position 55 mm (= 40 mm from the end of the substrate) from the end of the mounting table 1 and foreign matter having a size of 10 μm or more. Lines extending in the coating direction at positions of 40 mm intervals so as to be detected were designated as height profile measurement lines Pm2, Pm3... Pm14. That is, the height profile measurement line Pm14 is a line extending in the coating direction at a position 55 mm (= 40 mm from the substrate end opposite to the height profile measurement line Pm1) from the mounting table end opposite to the height profile measurement line Pm1. is there. At the center of each height profile measurement line Pmi (i = 1 to 14), a laser focus displacement meter having a spot diameter of about 2 μm was disposed as the height detector 4a. That is, 14 laser focus type displacement meters were arranged in the substrate width direction at a pitch of 40 mm.

  The measurement position on each height profile measurement line Pmi (i = 1 to 14) was given by 2001 points obtained by dividing a total distance of 1000 mm from the right end portion to the left end portion of the mounting table 1 at a pitch of 0.5 mm.

  Both the moving speed of the mounting table 1 and the height detector 4a, which are the measurement speeds of the height profile, were 10 m / min.

  Under the above conditions, first, in the first step, the height profile Shm10i (i = 1 to 14) of the mounting table 1 on the height profile measurement line Pmi (i = 1 to 14) was measured and stored.

  Next, in the second step, the height profile Shm1i (i = 1 to 14) of the coated surface 9a of the substrate 9 on the height profile measurement line Pmi (i = 1 to 14) was measured and stored.

  Next, the difference between the stored height profiles Shm1i (i = 1 to 14) and Shm0i (i = 1 to 14) is calculated to calculate the substrate height, and foreign matter is placed on the front and back of the substrate 9. Confirmed that there is no.

  Next, as a third step, a slit die 2d of the coating means 2 in FIG. 1 having a discharge width of 550 mm in the substrate width direction and a lip gap (shim thickness) of 500 μm is used. After lowering the slit die 2d so that the gap with the dielectric layer becomes 350 μm, a photosensitive glass paste made of glass powder and a photosensitive organic component and having a viscosity of 20000 mPa · sec is applied with a coating thickness of 300 μm and a coating speed of 3 m / second. It applied in minutes and the partition layer was formed.

  Next, in the fourth step, the height profile Shm2i (i = 1 to 14) of the coating film surface of the substrate 9 on the height profile measurement line Pmi (i = 1 to 14) was measured and stored.

  Then, the film thickness profile was calculated by taking the difference between the height profiles Shm1i (i = 1 to 14) and Shm2i (i = 1 to 14) stored before and after the application, and it was confirmed that there was no abnormality.

  Next, as a fifth step, the suction of the substrate 9 held by suction was released, and it was carried out from the mounting table 1 to the downstream step by the robot hand.

  As a post-process, the coated substrate 9 was dried at 100 ° C. for 20 minutes in a drying furnace using a radiation heater. When the partition wall coating film thickness distribution after drying was measured in the coating direction over the entire surface of the substrate 9, it was below the allowable range of 140 μm ± 3 μm. Next, the substrate 9 on which the partition layer was formed was exposed using a photomask designed to form a partition between adjacent electrodes, and development and baking were performed to form a striped partition. The partition walls had a pitch of 300 μm, a line width of 50 μm, a height of 140 μm, and the number of partition walls was 3073. In this way, a plasma display back plate having a predetermined shape of partition walls was obtained.

  The first step is performed only once for the first time, and then the previous step, the second step to the fifth step, and the subsequent step are repeated 1000 times. In the second step, the difference between Shm18 and Shm08 is obtained at the 100th sheet. Since the uplift of about 350 μm due to the foreign matter was observed, the raised position was confirmed with the actual product, and it was found that the foreign matter was sandwiched between the substrate 9 and the suction surface of the mounting table 1. After removing this foreign matter, again measuring the height profile of the coated surface 9a of the substrate 9 and taking the difference in the same manner, it was confirmed that there was no foreign matter on the front and back of the substrate 9, and the subsequent steps were performed. Continued.

  In the fourth step, an abnormality alarm was issued on the 200th sheet, and a difference between Shm112 and Shm212 was found to be about 15 μm thinner than 300 μm with respect to 300 ± 5 μm. When the difference between Shm112 and Shm012 including the position where the film thickness is thin was observed, no abnormality was found, so it was estimated that there was an abnormality in the coating means 2, and when the discharge port of the slit die 2d was checked, dirt was found. Since it was seen, the dirt was wiped off and the substrate 9 was discarded.

As described above, among the 1000 sheets, 999 sheets of the plasma display back plate on which good partition walls were formed were obtained, and further, R, G, and B phosphor pastes were sequentially applied by screen printing, After drying at 80 ° C. for 15 minutes and finally baking at 460 ° C. for 15 minutes, a back plate of a plasma display without defects could be produced. The surface quality of the obtained plasma display back plate was satisfactory. Next, the plasma display back plate and the front plate were put together, sealed, sealed with a mixed gas of 5% Xe and 95% Ne, and connected to a drive circuit to obtain a plasma display panel.
(Comparative example)
A plasma display back plate was manufactured in exactly the same manner as in Example except that Step 1 and the arithmetic processing (calculation of the substrate thickness) using Shm0i (i = 1 to 14) were omitted.

  As a result, foreign matter could not be detected at all, and the slit die 2d collided with the substrate 9 raised by the foreign matter, scratching the discharge port, and the substrate 9 was cracked. Therefore, it was replaced with a spare slit die and prepared so that the slit die could be filled with a coating solution and applied, and the broken substrate 9 was taken out and cleaned. For this reason, 50 of the 1000 substrates were broken and discarded. In addition, it took 2 hours to replace the slit die, and the operating rate was reduced accordingly.

It is a schematic front view of the die-coater 11 which is a coating device which concerns on one Embodiment of this invention. 3 is a schematic side view of a height measuring means 4. FIG. 2 is a plan view of the die coater 11. FIG. It is the figure which showed an example of the height profile Shm0i of the mounting base. It is the figure which showed an example of the height profile Sh1mi of the to-be-coated surface 9a of the board | substrate 9. FIG. It is the figure which showed an example of the board | substrate thickness profile Thm1i. FIG. 5 is a view showing a state in which a foreign object 10 is sandwiched between a substrate 9 and a mounting table 1. It is the figure which showed the example of the height profile Shm1i of the to-be-coated surface 9a of the board | substrate 9 in the state of FIG. It is the figure which showed the example of the thickness profile Thm1i of the board | substrate 9 in the state of FIG. It is the figure which showed an example of the thickness profile Thm2i of a coating film. It is the figure which showed the other example of the thickness profile Thm2i of a coating film. It is the figure which showed an example of the thickness profile Thm1i of the board | substrate 9 in the same height profile measurement line Pmi as FIG. It is the figure which showed another example of thickness profile Thmli of the board | substrate 9 in the same height profile measurement line Pmi as FIG. It is the top view which showed arrangement | positioning of the height detection means 4a in an Example. 6 is a graph showing the results of a model test in which beads are sandwiched between the mounting table 1 and the substrate 9.

Explanation of symbols

1: mounting table 1a: upper surface 2: coating means 2a: support 2b: guide 2c: holder 2d: slit die 2e: servo motor 2f: ball screw 3: moving means 3a: mount 3b: nut 3c: ball screw 3d: servo motor 3e: Guide 4: Height measuring means 4a: Height detector 4b: Height detector mounting column 5: Data processor 6: Display 7: Controller 8: Coating liquid supply means 8a: Coating liquid tank
8b: Coating liquid pump 8c: Piping 8d: Piping
9: Substrate 9a: Surface to be coated 9b: Surface to be held 10: Foreign matter 11: Die coater a1, a2: Thickness abnormal portion a3: Raised portion d: Ball equivalent diameter L1 of foreign matter 10 Measurement range length of height detector 4a Length L2: substrate raised portion length Pmi: height profile measurement line Shm0i: height profile Shm1i of mounting table 1: height profile Thm1i of substrate 9 to be coated Thm1i: thickness profile of substrate 9 Thm2i: thickness of coating film Profile

Claims (14)

  In the coating method in which the coating liquid is applied to the coated surface of the substrate from the coating means while the base material held by the holding means and the coating means are relatively moved, the coating liquid is disposed in a direction orthogonal to the coating direction of the coating means. The height measurement means having a plurality of height detectors is used to measure the height profile of the holding means before holding the base material, and the base material in a state where the base material is held by the holding means. The height profile of the coated surface is measured, and the thickness profile of the substrate is calculated from the height profile of the holding means and the height profile of the coated surface of the substrate. An application method characterized by performing an abnormality process if there is an abnormality in the determination.   In a coating method in which the coating liquid is applied to the coated surface of the substrate from the coating means while relatively moving the substrate held by the holding surface on the held surface and the coating means, the coating means is orthogonal to the coating direction of the coating means. Using the height measuring means having a plurality of height detectors arranged in the direction, the height profile of the surface to be held of the base material is measured while the base material is held by the holding means, The height profile of the coated surface is measured, and the thickness profile of the substrate is calculated from the height profile of the supported surface of the substrate and the height profile of the coated surface of the substrate. An application method characterized in that an abnormality process is performed if there is an abnormality by determining the presence or absence of the ink.   Further, after a coating liquid is applied to the coated surface of the substrate by the coating means to form a coated film, a height profile of the coated film is measured using the height measuring means, and the coated substrate is coated. Calculate the thickness profile of the coating film by calculating the surface height profile and the height profile of the coating film on the substrate, and determine whether there is an abnormality in the coating from the calculation result. The coating method of Claim 1 or Claim 2 to perform.   While measuring the height profile of the coated surface of the base material using the height measuring means with the base material held by the holding means, the height profile of the holding means and the height of the coated surface of the base material The thickness profile of the base material is sequentially calculated from the thickness profile, and the presence or absence of foreign matter is determined from the calculation result, and at the same time, the coating liquid is applied to the coated surface of the base material by the coating means to form a coating film. Item 2. The coating method according to Item 1.   While measuring the height profile of the surface to be coated of the base material using the height measuring means while holding the base material on the holding means, The thickness profile of the substrate is sequentially calculated from the height profile of the coated surface, and the presence or absence of foreign matter is determined from the calculation result, and at the same time, the coating liquid is applied to the coated surface of the substrate by the coating means. The coating method of Claim 2 which forms.   The coating according to claim 3, wherein a height profile of the coating film is measured simultaneously using the height measuring means while applying a coating liquid to the coated surface of the substrate by the coating means to form a coating film. Method.   The coating method according to claim 1, wherein the plurality of height detectors are arranged at a pitch in a range of 40 to 60 mm.   The manufacturing method of the member for plasma displays which manufactures the member for plasma displays using the coating method of Claims 1-7.   In a coating apparatus having a holding means for holding a base material, an application means for applying a coating liquid to a surface to be coated of the base material, and a moving means for moving the holding means and the coating means relative to each other, the coating device is orthogonal to the coating direction. A height measuring means having a plurality of height detectors arranged in the direction, and calculating the height profile of the holding means and the height profile of the coated surface of the substrate measured using the height measuring means A first computing means for processing and calculating a thickness profile of the base material; a first abnormality processing means for determining the presence or absence of foreign matter from the calculated base material thickness profile and performing an abnormal process if there is an abnormality; A coating apparatus comprising:   In a coating apparatus, comprising: a holding unit that holds a substrate on a surface to be held; an application unit that applies a coating liquid to the surface to be coated of the substrate; and a moving unit that relatively moves the holding unit and the coating unit. A height measuring means having a plurality of height detectors arranged in a direction perpendicular to the direction, a height profile of a surface to be held of the base material measured using the height measuring means, and a base material to be coated First processing means for calculating the thickness profile of the base material by calculating the surface height profile and determining the presence or absence of foreign matter from the calculated base material thickness profile and performing abnormality processing if there is an abnormality A coating apparatus, comprising: a first abnormality processing unit.   Furthermore, the thickness profile of the coating film is calculated by calculating the height profile of the coating film of the coating liquid on the substrate and the height profile of the coated surface of the substrate measured using the height measuring means. 11. The apparatus according to claim 9, further comprising: a second calculation unit; and a second abnormality processing unit that determines whether or not there is an application abnormality from the calculated coating film thickness profile and performs an abnormality process if there is an abnormality. The coating apparatus as described in.   The coating apparatus according to any one of claims 9 to 11, wherein the height detector measures the height in a non-contact manner with a laser beam.   11. The height detector according to claim 9, wherein the height detector uses air to float the detection unit on the object to be detected, and detects a position change of the detection unit to measure the height. Coating device.   The coating method according to any one of claims 8 to 12, wherein the plurality of height detectors are arranged at a pitch in a range of 40 to 60 mm.

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