JP5839670B2 - Coating device and landing state inspection method - Google Patents

Description

  The present invention relates to a coating apparatus that coats a substrate by an ink jet method and a landing state inspection method.

  In a flat panel display such as a color liquid crystal display, a color filter is used as a member forming the core of color formation. The color filter is formed by arranging a large number of fine R (red), G (green), and B (blue) pixels on a glass substrate.

  As an apparatus for producing this color filter, R, G, and B inks are ejected from an inkjet head and applied to a large number of fine pixel portions formed on a glass substrate, and R, G, and B color pixels are applied. Ink-jet devices that form the surface have been used in recent years.

  An inkjet head has a large number of nozzles that eject ink, and a plurality of color pixels can be simultaneously formed by simultaneously ejecting ink from these ejection nozzles to a plurality of pixel portions. Is not ejected normally, or if there is a foreign object near the nozzle, a defective color filter with color loss or color mixture will result. Therefore, it is necessary to detect in advance such an application failure factor that causes an abnormality in application, and to perform maintenance before applying ink to the substrate based on the detection result.

  Here, in the following Patent Document 1, as shown in FIG. 9, droplets are ejected from each nozzle onto a transparent body to form a landing pattern 91, and an image of this landing pattern and a normal landing pattern stored in advance are stored. To check whether the nozzle is normal or abnormal. Specifically, when the droplet is not in a predetermined position as shown in FIG. 9A, it is determined that the nozzle is clogged, and when the landing position is deviated from the predetermined position as shown in FIG. When the size of the landing pattern is abnormal as shown in FIG. 9C, it is determined that the nozzle discharge amount is abnormal. By doing so, it is possible to detect a nozzle with abnormal ejection that causes a coating failure and not to use the nozzle for coating.

Japanese Patent No. 4159525

  However, the landing state inspection method described in Patent Document 1 has a problem in that it is not possible to completely detect the cause of application failure. Specifically, as described above, defective coating may be caused not only by nozzle ejection abnormalities but also by foreign matter adhering to the vicinity of the nozzle, and foreign matter may be present in the ink applied to the substrate during application to the substrate. In the case of contact, the foreign substance drags the ink, thereby destroying the shape of the color pixel formed on the substrate and causing poor coating. However, the presence or absence of such foreign matter may not be detected by simply confirming the state of the ejected liquid droplets as in the inspection method disclosed in Patent Document 1, and the presence of foreign matter that may cause poor coating may be detected. There was a problem of overlooking.

  The present invention has been made in view of the above problems, and an object thereof is to provide a coating apparatus and a landing state inspection method having a landing state inspection mode for detecting a foreign matter that may cause a coating failure near the nozzle.

In order to solve the above problems, a coating apparatus of the present invention has a plurality of discharge nozzles for discharging droplets, each discharge nozzle being disposed on a discharge surface, and an inspection surface for landing droplets. A moving mechanism that relatively moves the discharge unit and the inspection surface in a direction parallel to the inspection surface, and moves each discharge unit while moving the discharge unit in the scanning direction by the moving mechanism. A coating mode in which a coating film is formed on the substrate by discharging droplets from the nozzle to the substrate, and a landing state inspection mode in which droplets are discharged from each discharge nozzle onto the inspection surface and the landing state of the droplets is inspected. In the landing state inspection mode, after the droplets are discharged onto the inspection surface to form a landing pattern, the discharge unit is configured so that the discharge surface passes over the landing pattern. Move in the scanning direction, and then move the discharge unit in a direction opposite to the previously moved direction so that the discharge surface again passes over the landing pattern, and the discharge unit moves in both directions After the inspection, the inspection is performed from the shape of each droplet of the landing pattern, and in the landing state inspection mode, the discharge unit is moved a plurality of times before the landing pattern is inspected. In this case, the movement in the direction perpendicular to the scanning direction is performed before the movement in both directions is completed and the next movement in both directions is performed .

According to the coating apparatus, after forming a landing pattern by discharging droplets onto the inspection surface, the discharge unit is moved in the scanning direction so that the discharge surface passes over the landing pattern. By moving the discharge unit in the direction opposite to the previously moved direction so that the discharge surface passes again, foreign matter that adversely affects the application of droplets in the application mode adheres to the discharge surface. In this case, the foreign object surely contacts the droplet and drags the droplet.Therefore, by evaluating the shape of each droplet in the landing pattern after the ejection unit has moved in both directions, It is possible to inspect. In addition, by moving in the direction orthogonal to the scanning direction before the movement in both directions is completed after the movement in both directions is completed, the position of the discharge unit and the droplet in the direction orthogonal to the scanning direction is determined. Since the movement in both directions of the scanning direction is repeated while changing the relationship little by little, foreign matter adheres to the intermediate position between adjacent discharge nozzles or the intermediate position between adjacent discharge units, and so on. Even when there is a possibility that the foreign matter does not come into contact with the droplet, the foreign matter can be detected more reliably by bringing the foreign matter into contact with the droplet.

Further, the distance between the ejection surface and the inspection surface when moving the ejection unit in the landing state inspection mode is equal to or less than the distance between the ejection surface and the substrate when scanning the ejection unit in the coating mode. There may be.

  By doing so, the distance between the ejection surface and the inspection surface when moving the ejection unit in the ejection inspection mode is equal to or less than the distance between the ejection surface and the substrate when scanning the ejection unit in the coating mode. In addition to detecting foreign substances that adhere to the surface and affect the coating, it is also possible to detect small foreign objects that do not come into contact with the droplets applied to the substrate. It is also possible to prevent the occurrence of poor coating due to falling on the substrate.

  In the landing state inspection mode, when the landing pattern is formed, the discharge unit may discharge a plurality of droplets to the same location on the inspection surface.

  In this way, by discharging a droplet several times to the same location on the inspection surface and increasing the height of the droplet, if the foreign material adheres to the discharge surface, the foreign material is more reliably Since it contacts the droplet, it is possible to detect the foreign matter adhering to the ejection surface with higher accuracy.

In order to solve the above problems, the landing state inspection method of the present invention includes a discharge unit having a plurality of discharge nozzles for discharging droplets, each discharge nozzle being disposed on a discharge surface, and a droplet landing A landing state inspection method for a coating apparatus, comprising: an inspection surface to be moved; and a moving mechanism that relatively moves the discharge unit and the inspection surface in a direction parallel to the inspection surface. Forming a landing pattern by discharging droplets onto the inspection surface, and after the pattern formation step, the discharge unit is moved so that the discharge surface passes over the landing pattern, Further, the landing pattern after the discharge unit has moved in both directions by moving the discharge unit in a direction opposite to the previous movement direction so that the discharge surface again passes over the landing pattern. It possesses an inspection step of inspecting the shape of the droplet, and in the inspection process, and carried out several times to move to the both directions of one discharge unit before performing inspection of the landing pattern, in which, The movement in the direction orthogonal to the scanning direction is performed before the movement in both directions is completed and the next movement in both directions is performed .

According to the landing state inspection method, after the pattern formation step, the discharge unit is moved so that the discharge surface passes over the landing pattern, and then the discharge surface again moves over the landing pattern. By moving the discharge unit in the direction opposite to the previous movement direction so that it passes, if foreign matter that adversely affects the application of droplets in the application mode is attached to the discharge surface, Since foreign matter reliably contacts and drags the droplet, it is possible to inspect the presence or absence of this foreign matter by evaluating the shape of each droplet in the landing pattern after the discharge unit has moved in both directions. is there. In addition, by moving in the direction orthogonal to the scanning direction before the movement in both directions is completed after the movement in both directions is completed, the position of the discharge unit and the droplet in the direction orthogonal to the scanning direction is determined. Since the movement in both directions of the scanning direction is repeated while changing the relationship little by little, foreign matter adheres to the intermediate position between adjacent discharge nozzles or the intermediate position between adjacent discharge units, and so on. Even when there is a possibility that the foreign matter does not come into contact with the droplet, the foreign matter can be detected more reliably by bringing the foreign matter into contact with the droplet.

  According to the coating apparatus and the landing state inspection method described above, it is possible to detect foreign matter that may cause poor coating attached to the ejection surface, and to perform stable coating by removing the foreign matter immediately after detection. Is possible.

It is a mimetic diagram showing one embodiment of the present invention, and is a side view. It is the schematic of a test | inspection surface and an image acquisition part, and is a perspective view. It is a schematic diagram showing a landing pattern of the inspection liquid that has landed on the inspection surface. It is a schematic diagram which shows the process in which a coating defect arises by the contact of a foreign material. It is a schematic diagram which shows the process of moving a coating head to one direction and performing a landing state test | inspection. It is a schematic diagram which shows the process of moving an application | coating head to a reverse direction and performing a landing state test | inspection. It is a schematic diagram which shows the landing pattern after moving a coating head. It is an operation | movement flow of the landing state test | inspection mode in this embodiment. It is a schematic diagram which shows the conventional landing state test | inspection.

  FIG. 1 is a schematic diagram showing an embodiment of the present invention. The coating apparatus 1 includes a coating unit 2, a coating stage 3, a measuring device 4, and a control unit 5, and a discharge nozzle in the coating unit 2 while the coating unit 2 moves above the substrate W on the coating stage 3. A coating operation on the substrate W is performed by discharging droplets of the coating liquid from the substrate. In addition, the application unit 2 ejects droplets to the measuring device 4, and the control unit 5 inspects the landing state of the droplets acquired by the measuring device 4, and based on the result, abnormal landing can be detected and used. Selection of the proper discharge nozzle is performed.

  In the following description, the direction in which the coating unit 2 moves when droplets are discharged onto the substrate W is the X-axis direction (or scanning direction), and the direction orthogonal to the X-axis direction on the horizontal plane is the Y-axis direction, X-axis, and The description proceeds with the direction orthogonal to both the Y-axis directions as the Z-axis direction.

  The coating unit 2 includes a coating head 10 and a coating head moving device 12. The coating head 10 can be moved to a discharge target such as a substrate W on the coating stage 3 and an inspection surface 31 of the measuring device 4 described later by the coating head moving device 12. After moving to each discharge target, the coating head 10 is A droplet is discharged from the discharge nozzle 11 to each discharge target.

  The coating head 10 has a substantially rectangular parallelepiped shape with the Y-axis direction as the longitudinal direction, and a plurality of discharge units 13 are incorporated therein. The discharge unit 13 is provided with a plurality of discharge nozzles 11, and has a nozzle plate 14 (discharge surface) on the lower surface, and each discharge nozzle 11 is arranged on the nozzle plate 14. By incorporating the discharge unit 13 into the coating head 10, the discharge nozzles 11 are arranged on the lower surface of the coating head 10. The coating head 10 is connected to the sub tank 15 through a pipe. The sub-tank 15 is provided in the vicinity of the coating head 10, temporarily stores the coating solution supplied from the main tank 16 provided at a distance through the pipe, and supplies the coating solution to the coating head 10 with high accuracy. Have a role. The coating liquid supplied from the sub tank 15 to the coating head 10 is branched in the coating head 10 and supplied to all the discharge nozzles 11 of each discharge unit 13.

  Here, in order to stabilize the discharge of the liquid droplets from each discharge nozzle 11, the coating liquid needs to maintain a predetermined shape interface (meniscus) in each discharge nozzle 11 during application standby, A predetermined negative pressure is applied to the sub tank 15 by a vacuum source 17. This negative pressure is regulated by a vacuum pressure regulating valve 18 provided between the sub tank 16 and the vacuum source 17.

  Then, droplets of the coating liquid are ejected from these ejection nozzles 11, whereby droplets are ejected from the coating head 10 to the substrate W and the inspection surface 31. In addition, each discharge nozzle 11 has a discharge drive unit (not shown), and the discharge drive unit of any discharge nozzle 11 operates by controlling the discharge on / off in each discharge nozzle 11 from the control unit 5. , Eject droplets. In the present embodiment, a piezo actuator is used as the ejection drive unit.

  The moving device 12 is a linear motion mechanism composed of a linear stage or the like, and can move the coating head 10 assembled thereto in the X-axis direction. By controlling the driving of the coating head moving device 12 by the control unit 5, the coating head 10 can move relative to the substrate W and an inspection surface 31 described later, and above the substrate W and the inspection surface 31. It is possible to move upward. Further, by driving the coating head moving device 12, the coating head 10 is scanned on the substrate W in the coating mode, and the droplets are continuously ejected from each ejection nozzle 11, thereby coating the substrate W. It is possible to apply a liquid.

  In the present embodiment, the coating head 10 can be moved not only in the X-axis direction but also in the Y-axis direction by a moving device (not shown). As a result, when the discharge units 13 are installed at intervals in the application head 10, the application head 10 is shifted in the Y-axis direction after application once, and the application is performed so as to complement the interval. Thus, coating can be performed on the entire surface of the substrate W. Even when the width of the substrate W in the Y-axis direction is longer than the length of the coating head 10, the coating head 10 is shifted in the Y-axis direction every time a coating operation is completed, and divided into multiple times. By applying, it is possible to apply to the entire surface of the substrate W.

  The application stage 3 has a mechanism for fixing the substrate W, and the application operation to the substrate W is performed with the substrate W placed on the application stage 3 and fixed. In the present embodiment, the coating stage 3 has a suction mechanism, and operates a vacuum pump (not shown) to generate a suction force on the surface in contact with the substrate W, thereby fixing the substrate W by suction.

  The measuring device 4 includes an inspection surface 31 and an image acquisition unit 40. The measurement of the landing state by the measuring device 4 is performed before the above-described coating operation is started or during the coating operation. First, after the coating head 10 moves above the inspection surface 31, the ejection nozzle 11 moves to the inspection surface 31. The droplets are discharged toward the surface, and the droplets land on the inspection surface 31 to form a landing pattern 21. The image acquisition unit 40 acquires image data of the inspection surface 31 on which the landing pattern 21 is formed. The acquired image data is transferred to an analysis device 51 to be described later, and the landing state such as the landing area, landing position, and landing shape of the droplets discharged from each discharge nozzle 11 is analyzed based on the data.

  Details of the configuration of the inspection surface 31 and the image acquisition unit 40 are shown in FIG. In the present embodiment, the inspection surface 31 is a belt-like film 32, and both ends thereof are connected to a winding roller and a winding roller (not shown). Here, when the take-up roller rotates under the control of the control unit 5, the belt-like film 32 is taken up, and at the same time, the belt-like film is unwound from the supply roller. By performing the winding and unwinding operations of the belt-shaped film 32 before the landing state measurement, the landing pattern 21 can be formed in a place where there is no droplet or foreign matter, and the landing state measurement can be performed.

  Further, it is not necessary to perform the winding and unwinding operations every time the landing state measurement is performed. After the previous landing state measurement, the landing state measurement can still be performed on the strip film 32 ( If an area (with no droplets or foreign matter) remains, the area may be used by changing the position of the coating head 10 in the next landing state measurement. In this case, as a result of performing the landing state measurement a plurality of times, when there is no area on the belt-like film 32 where the landing state measurement can be performed, the winding and unwinding operations are performed, and droplets and foreign matter The surface without is prepared. In this embodiment, the landing state measurement is performed about eight times while shifting the discharge position in the X-axis direction with respect to the strip film 32 having a width of 100 mm in the X-axis direction, and then the winding and unwinding operations are performed. Yes. By doing so, the landing state measurement is performed using the strip film 32 efficiently and without being affected by the landing pattern 21 formed by other landing state measurement.

  A plurality of guide rollers 33 are in contact with the belt-like film 32 between the winding roller and the take-up roller, and the landing area 34 where the droplets on the belt-like film 32 indicated by the chain line in the figure land horizontally. Thus, the belt-like film 32 is guided by a guide roller 33. A suction table 35 for sucking the belt-like film 32 is provided below the landing area 34. The suction table 35 has a substantially flat surface in contact with the belt-like film 32. Further, the surface in contact with the belt-like film 32 has a suction port, and can have a suction force by driving a vacuum pump (not shown). During the landing state measurement, the suction table 35 sucks and fixes the belt-like film 32 corresponding to the region including the landing region 34, so that the position of the landing pattern 21 is shifted in the portion covering the landing region 34 during the landing state measurement. Is preventing.

  The image acquisition unit 40 includes an image recognition camera 41, a first camera moving device 42, and a second camera moving device 43. The image recognition camera 41 is assembled to the first camera moving device 42 and the second camera moving device 43, and by driving these moving devices, the image recognition camera 41 moves in the X-axis direction and the Y-axis direction. Is possible.

  In this embodiment, the image recognition camera 41 is a monochrome CCD camera, and the image acquisition timing can be controlled from the outside. By giving an instruction from the control unit 5, the image recognition camera 41 continuously acquires image data, and the acquired image data is transferred to an analysis device 51 described later via a cable.

  The first camera moving device 42 is a linear motion mechanism constituted by a linear stage or the like, and can move the image recognition camera 41 in the longitudinal direction (Y-axis direction) of the coating head 10. Further, the second camera moving device 43 is a linear motion mechanism constituted by a linear stage or the like, and the image recognition camera 41 and the first camera moving device 42 are scanned in the direction in which the coating head 10 scans during coating (X-axis direction). It is possible to move.

  Here, by controlling the driving of the first camera moving device 42 and the second camera moving device 43 by the control unit 5, the image recognition camera 41 is relatively relative to the inspection surface 31 in the X-axis direction and the Y-axis direction. It is possible to move. All the landing patterns 21 formed in the landing area 34 are imaged by driving these moving mechanisms during the landing state measurement and continuously acquiring the image data of the inspection surface 31 while the image recognition camera 41 moves. And can be measured.

  In addition, when the droplets are landed on the inspection surface 31, the coating head 10 needs to be positioned directly above the inspection surface 31, so that the application head 10 is moved to the inspection surface 31 by driving the second camera moving device 43. While positioned directly above, the image recognition camera 41 can be moved in the X-axis direction and retracted.

  As another configuration of the image acquisition unit 40, a plurality of image recognition cameras 41 are provided side by side in the Y-axis direction, and the image recognition camera 41 acquires all the images of the landing patterns 21 without moving during image acquisition. It may be a configuration.

  The control unit 5 includes a computer, a sequencer, and the like. Liquid feeding to the coating head 10, ejection of droplets from the ejection nozzle 11 and adjustment of the ejection amount, image acquisition by the image recognition camera 41, driving of each moving mechanism, etc. Control the operation of. Furthermore, in the present embodiment, the coating apparatus 1 has a coating mode and a landing state inspection mode, and in the coating mode, the ejection head 10 moves in the scanning direction (X-axis direction) above the substrate W while ejecting nozzles. The control unit 5 performs control so that the droplets are discharged from 11. The landing state inspection mode further includes a pattern formation process and an inspection process. In the pattern formation process, droplets are ejected from the discharge nozzle 11 on the inspection surface 31 to form the landing pattern 21, and in the inspection process, a pattern is formed. The control unit 5 performs control so as to determine whether the landing pattern 21 formed in the forming process is good or bad and detect foreign matter therefrom.

  In addition, the control unit 5 includes an analysis device 51, and determines whether the landing state of each landing pattern 21 is good or not based on the image of the landing pattern 21 obtained by the image recognition camera 41.

  The analysis device 51 is a computer having a CPU, a RAM, and a ROM, and confirms the landing state of each landing pattern 21 from an image obtained by the image recognition camera 41. The analysis device 51 includes an image processing unit that extracts the outer shape data of the landing pattern 21 from the image data based on the luminance information of each constituent pixel of the image data, and the center of gravity from the outer shape data of each landing pattern 21 extracted by the image processing unit. A program for executing each function such as an analysis unit that calculates landing state data such as position, shape, and area, and determines the quality of the discharge state of the discharge nozzle 11 that forms each landing pattern 21 from these data. It is remembered. The analysis device 51 includes a storage device that stores various information including a hard disk, a memory such as a RAM or a ROM, and the landing state of each landing pattern 21 calculated by the image data and the analysis unit. Data, reference data at the time of pass / fail judgment (data of landing state when droplets are normally ejected from each ejection nozzle 11), threshold data, information on usable ejection nozzles 11 and the like are stored in this storage device. Is done.

  The analysis device 51 is connected to the image recognition camera 41 via a cable, and can capture the image data acquired by the image recognition camera 41 and store it in the storage device.

  Here, the inspection process in the landing state inspection mode includes a pass / fail determination process, and determines the pass / fail of the landing pattern 21. This pass / fail determination step will be described below.

  First, for the image data of each landing pattern 21 captured in the analysis device 51 itself, the image processing unit measures the luminance value for each constituent pixel of the image data. Then, based on information on the degree of change in luminance value between adjacent pixels obtained by measuring the luminance value, the image processing unit extracts outline data of each landing pattern 21 from the image data. Here, in the present embodiment, when extracting the outer shape data of the landing pattern 21, in order to more clearly confirm the outer shape of the landing pattern 21 and facilitate the extraction, the image processing unit first constructs the image data. A predetermined luminance value is binarized as a threshold value with respect to the luminance of each pixel, and is replaced with, for example, black and white data in which a droplet portion is black and other portions are white. Extracting outline data.

  Then, the analysis unit calculates landing state data such as the position of the center of gravity, the landing shape, and the landing area for each external shape data.

  As a method of calculating the center of gravity position of the outer shape data of each landing pattern 21, for example, a method of obtaining rectangles that circumscribe each of the outer shape data of each landing pattern 21 and calculating the center of gravity of the rectangle is used. In addition, the landing shape of each landing pattern 21 is obtained using a method for obtaining the circularity of the outer shape data. Further, the landing area of each landing pattern 21 is obtained by using a method for calculating the number of pixels forming the outer shape data on the image data.

  Next, the analysis unit of the analysis device 51 determines whether the landing state of each landing pattern 21 is good or bad. An example of detection of landing NG at this time is shown in FIG. First, as shown in FIG. 3A, the data of the center of gravity, the circularity, and the area of each landing pattern 21 when the ejection from all the ejection nozzles 11 is normal are calculated, and the analysis device is used as reference data in advance. Calculated and stored in 51 storage devices. Further, data on the range (threshold value) of the difference in landing state in which the actually ejected landing pattern 21 is allowed with respect to the reference data is also set in advance as an inspection condition and stored in the storage device of the analysis device 51. Has been.

  Here, it is assumed that droplets are actually ejected from the coating head 10 and land on the inspection surface 31 to draw the landing pattern 21 of FIG. The image data of the landing pattern 21 is acquired by the image recognition camera 41 and transferred to the analysis device 51. Then, the center of gravity position, circularity, and area of each landing pattern 21 are calculated from the acquired image data by the analysis unit of the analysis device 51, and the difference between them and the reference data is evaluated.

  When FIG. 3 (b) is confirmed, the point indicated by A in FIG. 3 (b) is different in that the position of the center of gravity is deviated from the reference data. In detecting the shift of the center of gravity position, the analysis unit calculates the center of gravity position of the landing pattern 21 in FIG. 3B and calculates the difference from the reference data. First, the location indicated by A in FIG. Then, it is recognized that there is a difference of d. Here, in the analysis device 51, a threshold value d ′ is set and stored in advance as an allowable range of the center of gravity position difference, and the analysis unit confirms the magnitude of the landing position by checking the magnitude of d and d ′. Judge the quality. If d is equal to or less than d ', the analysis unit determines that the difference in the center of gravity is within an allowable range, and determines that the landing is normal. On the contrary, if d is larger than d ', the analysis unit determines that the difference in the center of gravity is outside the allowable range, and determines that the landing is abnormal.

  In addition to the abnormal gravity at the center of gravity as shown in A of FIG. 3B, the abnormal landing phenomenon has a teardrop-like shape instead of a circle as shown in B of FIG. 3B. Or an elliptical shape having an abnormality in shape, and an abnormality in the area of the landing pattern 21 as indicated by C in FIG. Here, as described above, the center of gravity position, the circularity, and the area are calculated for each landing pattern 21, and it is evaluated whether the difference between them and the reference data is within a predetermined threshold value. It is possible to detect landing abnormalities such as A, B, and C in FIG.

  When these landing abnormalities appear alone or in combination in the landing pattern 21, the analysis unit determines that the landing pattern 21 is NG. In addition, when an abnormal landing due to such abnormal discharge of the discharge nozzle 11 is detected, information indicating that the discharge nozzle 11 that discharged the abnormal landing droplet is NG is output from the analysis device 51 to the control unit or the like. The

  The quality of each landing pattern 21 is determined by the above method. And the discharge nozzle 11 which became NG by this determination becomes use NG, and based on the information, the information of the usable discharge nozzle 11 memorize | stored in the memory | storage device of the analyzer 51 is updated, and after that. For the application to the substrate W and the discharge to the inspection surface 31, the discharge nozzle 11 determined to be NG is not used.

  The inspection process in the landing state inspection mode further includes a foreign matter detection process. This foreign matter detection step will be described below.

  First, FIG. 4 schematically shows a process in which defective coating occurs due to the presence of foreign matter.

  If the use of the coating apparatus 1 is continued, foreign matter may adhere to the nozzle plate 14 on which the discharge nozzles 11 are arranged. This foreign matter is, for example, particles adhered to the inside of the coating apparatus 1 or the substrate W, a part of a cleaning member (fiber waste etc.) for cleaning the nozzle plate 14, or the nozzle plate 14 that cannot be wiped off by cleaning. Such as a droplet.

  Here, as described above, in this embodiment, droplets are continuously discharged from the discharge nozzle 11 while driving the coating head moving device 12 to scan the coating head 10 in the X-axis direction on the substrate W. By doing so, the coating liquid is applied to the substrate W. At this time, as shown in FIG. 4A, when the foreign matter 22 is attached to the nozzle plate 14, the foreign matter 22 is landed when the nozzle plate 14 passes over the landing pattern 21 formed on the substrate W. 21 is touched and the landing pattern is dragged as it is. As a result, as shown in FIG. 4B, the landing pattern 21 is deformed, resulting in poor coating, and the entire substrate W becomes a defective product.

  In order to prevent application failure due to the adhesion of the foreign matter 22, it is necessary to quickly remove the foreign matter 22 from the nozzle plate 14. For this reason, the presence of the foreign matter 22 is quickly detected by the foreign matter detection step.

  Therefore, in the present invention, in the landing state inspection mode, after the landing pattern 21 is formed on the inspection surface 31 in the pattern formation step, the coating head 10 is moved in the scanning direction (X-axis direction) by the moving device 12, and thereafter A foreign matter detection process is performed on the landing pattern 21. This operation will be described below with reference to FIGS.

  FIG. 5 shows an example in which the application head 10 is moved in one direction and a landing state inspection is performed. As shown in FIG. 5A, first, droplets are discharged from the discharge nozzles 11 of the coating head 10 onto the inspection surface 31 to form the landing pattern 21. Thereafter, the coating head 10 is moved in the X-axis direction. In this way, when the foreign material 22 is behind the droplet pattern 21 in the moving direction of the coating head 10 as shown in FIG. 5A, the nozzle plate 14 passes over the landing pattern 21. Since the foreign matter 22 contacts the landing pattern 21, the foreign matter 22 drags the landing pattern during the movement of the coating head 10. When the movement is completed, the landing pattern 21 is deformed as shown in FIG. It becomes a state. By confirming the presence or absence of this trace, the presence or absence of the foreign matter 22 can be confirmed. In addition, when the coating head 10 is moved, the landing pattern 21 may be formed while the coating head 10 is moved. After the landing pattern 21 is formed, the coating head 10 may be continuously moved by a predetermined distance.

  Here, the moving distance of the coating head 10 may be a distance corresponding to one droplet, but for example, as shown in FIG. 5B, the entire nozzle plate 14 passes through a region where the landing pattern 21 exists. Thus, it is desirable to set it long. By doing so, the foreign matter 22 drags the plurality of droplet patterns 21, so that the foreign matter 22 can be easily detected.

  On the other hand, as shown in FIG. 6A, when the foreign material 22 is ahead of the droplet pattern 21 with respect to the moving direction of the coating head 10, the coating head 10 is moved after the landing pattern 21 is formed. Even in the state 6 (b), since the foreign matter 22 does not contact the landing pattern 21, the shape of the landing pattern 21 does not collapse, and the foreign matter 22 cannot be detected even if the shape of the landing pattern 21 is confirmed. Therefore, in the present invention, after the state of FIG. 6B is reached, the coating head 10 is also moved in the direction opposite to the direction of movement at that time, and the state shown in FIG. 14, the foreign matter 22 and the landing pattern 21 are surely in contact with each other regardless of where the foreign matter 22 is attached. After moving the coating head 10 in both directions as described above, the state of the landing pattern 21 is acquired by the image recognition camera 41, the image is evaluated by the analysis device 51, and the presence / absence of the landing pattern 21 having a deformed shape is determined. By checking, it is possible to inspect for the presence or absence of the foreign matter 22.

  Here, when the interval between the discharge nozzles 11 adjacent to each other in the Y-axis direction is wide, the coating head 10 only moves in both directions in the X-axis direction even if the foreign matter 22 is attached to an intermediate position between the two discharge nozzles 11. Then, there is a possibility that the foreign object 22 does not contact the landing pattern 21 and cannot be detected. In addition, even when the interval between the adjacent discharge units 13 is wide, if the foreign matter 22 adheres to an intermediate position between the two discharge units 13, the foreign matter 22 may not be detected in the same manner.

  In such a case, once the coating head 10 has moved in both directions in the X-axis direction, the coating head 10 has moved in the Y-axis direction so that these foreign matters 22 can come into contact with the landing pattern 21, and It is better to move in both directions in the X-axis direction again. For example, between the movement in both directions in the X-axis direction and the movement in the next two directions, movement in the Y-axis direction that is half the distance between the discharge nozzles 11, or Y axis corresponding to the distance between the discharge units 13 It is better to move in the direction. In this way, the foreign object 22 and the landing pattern 21 are more reliably brought into contact with each other and the foreign object 22 is detected by performing the movement in both directions in the X-axis direction a plurality of times with the movement in the Y-axis direction interposed therebetween. Is possible. Further, the movement in both directions in the X-axis direction is not limited to once or twice, and may be performed three or more times while gradually changing the position of the coating head 10 in the Y-axis direction. As the number of times of movement in both directions in the X-axis direction increases, the foreign object 22 can be detected more reliably.

  Further, the distance d2 between the nozzle plate 14 and the inspection surface 31 when moving the coating head 10 shown in FIG. 6A is the distance between the nozzle plate 14 and the substrate W shown in FIG. It is desirable that it is d1 or less. In this way, in addition to detecting the foreign material 22 that adheres to the nozzle plate 14 and affects the coating, it is also possible to detect a small foreign material 22 that does not come into contact with the droplets applied to the substrate W. It becomes possible to prevent the foreign matter 22 from dropping on the substrate W during the coating mode and causing defective coating. In this way, when the distance d2 is set to be equal to or less than d1, the distance between the nozzle plate 14 and the inspection surface 31 may be set to d2 from when the droplet is ejected. The distance from the inspection surface 31 may be reduced to d2.

  Further, when the landing pattern 21 is formed, the discharge unit may discharge the liquid droplets to the same location on the inspection surface 31 a plurality of times. In this way, by increasing the height of the liquid droplet, when the foreign material 22 adheres to the nozzle plate 14, the foreign material 22 more reliably contacts the liquid droplet, so that the foreign material 22 can be detected with higher accuracy. can do.

  Next, the state of the landing pattern 21 after the application head 10 is moved is shown in FIG.

  When the nozzle plate 14 is located at the position (a) indicated by a two-dot chain line in FIG. 7, droplets are ejected from the ejection nozzle 11 to form the landing pattern 21, and then the nozzle plate 14 together with the coating head 10. And the nozzle plate 14 is moved to the position (b). At that time, when the foreign material 22 is present at the position shown in the drawing, the nozzle plate 14 moves in a state where all the landing patterns 21 with which the foreign material 22 has contacted are dragged. Therefore, as shown in the drawing, the landing pattern 21 whose shape has been destroyed by the foreign matter 22 is in a state of being aligned in the moving direction of the foreign matter 22, that is, the X-axis direction. Therefore, when the image of the landing pattern 21 is evaluated by the analysis device 51, when it is confirmed that a plurality of landing patterns 21 whose shapes are collapsed are arranged in the X-axis direction, this adheres to the nozzle plate 14. It can be determined that it is due to the foreign matter 22.

  Next, an operation flow of the landing state inspection mode by the coating apparatus 1 is shown in FIG. The following steps S4 to S6 correspond to the pattern formation process, and steps S7 to S20 correspond to the inspection process.

  First, on the inspection surface 31, an area (with no droplets or foreign matter) that can perform landing state measurement is secured. Specifically, the suction fixing of the suction table 35 is released (step S1), the inspection surface 31 is wound up by a predetermined length by rotating the take-up roller (step S2), and the suction of the suction table 35 is renewed. Fixing is performed (step S3). Here, before performing this step, this step may be skipped if there is a remaining area on the inspection surface 31 where the landing state measurement can be performed.

  Next, the image recognition camera 41 is retracted by driving the second camera moving device 43 so as not to interfere with the coating head 10 on the inspection surface 31 (step S4). When the retreat of the image recognition camera 41 is completed, the coating head moving device 12 is driven to move the coating head 10 to the inspection surface 31 (step S5).

  Next, droplets are discharged from the discharge nozzles 11 to the inspection surface 31, and the landing pattern 21 is formed (step S6). In the present embodiment, droplets are ejected with the movement of the coating head 10 in the scanning direction (X-axis direction).

  When the discharge of droplets from the discharge nozzle 11 is completed, the coating head 10 moves in the X-axis direction (step S7), and then the coating head 10 moves in the direction opposite to the moving direction (step S8). By this reciprocating operation, a state in which the foreign matter 22 drags the droplet pattern 21 occurs when the foreign matter 22 exists on the nozzle plate 14. In step S7, it does not matter which direction the coating head 10 moves from in the X-axis direction. Further, in this embodiment, following the movement operation of the coating head 10 in step S6, the movement in step S7 in the same direction is performed.

  When the reciprocating operation of the coating head 10 on the inspection surface 31 is completed, the coating head moving device 12 is driven to retract the coating head 10 so that an image of the landing pattern 21 can be acquired (step S9). After the evacuation is completed, the first camera moving device 42 and the second camera moving device 43 are driven to move the image recognition camera 41 to a position directly above the inspection surface 31 (step S10). Then, the image recognition camera 41 is continuously moved while the image recognition camera 41 is moved by the first camera moving device 42 and the second camera moving device 43, whereby the image data of the landing states of all the landing patterns 21 is acquired ( Step S11). The image data is transferred to the analysis device 51 and stored in the storage device (step S12).

  Next, the outer shape data of the landing pattern 21 is extracted from the image data stored in the analysis device 51 by the image processing unit of the analysis device 42 (step S13), and the analysis unit of the analysis device 51 then extracts the landing pattern 21. Landing state data of each landing pattern 21 is calculated from the outer shape data (step S14).

  Next, whether each landing pattern 21 is good or bad is determined based on the landing status data of each landing pattern 21 obtained (step S15). The ejection nozzle 11 that ejects the droplets of the pattern 21 is detected (step S16).

  Next, based on the determination result of the landing state, the presence / absence of landing abnormality due to the foreign matter 22 attached to the nozzle plate 14 is determined. Specifically, it is determined whether or not there is a landing pattern 21 that is dragged by the foreign material 22 and becomes NG in a plurality in the X-axis direction (step S17).

  If it is determined in step S17 that there is no landing abnormality due to the foreign matter 22, the landing pattern 21 that is NG in this landing state inspection is considered to be due to the discharge nozzle 11 that formed the landing pattern 21, and this If the application conditions are set so as not to use the discharge nozzle 11, the subsequent application operation can be performed without performing nozzle cleaning or the like. Therefore, the usable nozzle information stored in the storage device of the analysis device 51 is updated so that the discharge nozzle 11 which is reflected as a result of this inspection and becomes NG is not used for the subsequent coating operation (step S18), and a series of steps. The landing state inspection operation is completed.

  On the other hand, if it is determined in step S17 that there is an abnormal landing due to the foreign material 22, if the coating operation is continued without removing the foreign material 22, the foreign material 22 drags the droplet applied to the substrate W. Therefore, it is necessary to stop the application operation. Therefore, firstly, the usable nozzle information stored in the storage device of the analysis device 51 is updated so that the ejection nozzle 11 in which the landing abnormality other than the landing abnormality due to the foreign matter 22 has occurred is not used for the subsequent coating operation. (Step S19) Next, the operation is stopped with an alarm or the like, and the application operation is stopped until it is confirmed that the foreign matter 22 has been removed (Step S20).

  By the coating apparatus and the landing state inspection method having the landing state inspection operation as described above, the foreign matter 22 that may cause a coating failure adhered to the nozzle plate 14 can be detected, and the foreign matter 22 is removed immediately after detection. Thus, it is possible to perform application with stable quality.

  In the above description, in order to detect the foreign matter attached to the nozzle plate 14, the entire nozzle plate 14 is moved so as to pass the landing pattern 21, and the landing state inspection is performed. The inspection may be performed by moving the entire 10 so as to pass through the landing pattern 21 so that the foreign matter attached to the coating head 10 can be detected.

  In addition, the configuration in which the coating head 10 and the image recognition camera 41 move relative to the coating stage 3 and the inspection surface 31 includes the second camera moving device 43 and the coating head moving device 12 in the present embodiment. The image recognition camera 41 is independently moved in the X-axis direction, but the application head 10 and the image recognition camera 41 are fixed together on one frame and moved in the X-axis direction. Thus, the above two moving mechanisms may be combined into one.

  In addition, a moving mechanism is not provided in the coating head 10 and the image recognition camera 41, but a moving mechanism is provided in the inspection surface 31 and the coating stage 3, and the inspection surface 31 and the coating stage 3 with respect to the coating head 10 and the image recognition camera 41 are provided. May be configured to move relative to each other.

  In addition, the image recognition camera 41 and the analysis device 51 may not be provided, and the landing pattern 21 of the droplets discharged onto the inspection surface 31 may be visually confirmed to inspect for the presence or absence of landing abnormality.

  The inspection surface 31 may be not only a film shape as in the present embodiment but also a plate shape such as a glass plate. However, in this case, it is necessary to replace the inspection surface 31 every time there is no area for ejecting droplets. Further, instead of providing the inspection surface 31 separately for the substrate W, droplets may be ejected onto the substrate W to form the landing pattern 21, and the ejection state inspection may be performed on the landing pattern 21.

DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 2 Application | coating part 3 Application | coating stage 4 Measuring apparatus 5 Control part 10 Application | coating head 11 Discharge nozzle 12 Application | coating head moving apparatus 13 Discharge unit 14 Nozzle plate 15 Sub tank 16 Main tank 17 Vacuum source 18 Vacuum pressure regulation valve 21 Landing pattern 22 Foreign material 31 Inspection surface 32 Band-shaped film 33 Guide roller 34 Landing area 35 Suction table 40 Image acquisition unit 41 Image recognition camera 42 First camera moving device 43 Second camera moving device 51 Analyzing device 91 Landing pattern W substrate

Claims (6)

A discharge unit having a plurality of discharge nozzles for discharging droplets, each discharge nozzle being disposed on a discharge surface;
An inspection surface for landing droplets;
A moving mechanism for relatively moving the discharge unit and the inspection surface in a direction parallel to the inspection surface;
With
A coating mode in which a coating film is formed on the substrate by ejecting droplets from each ejection nozzle to the substrate while moving the ejection unit in the scanning direction by the moving mechanism;
A landing state inspection mode in which a droplet is discharged from each discharge nozzle onto the inspection surface, and a landing state of the droplet is inspected,
A coating device comprising:
In the landing state inspection mode, after a droplet is discharged onto the inspection surface to form a landing pattern, the discharge unit is moved in the scanning direction so that the discharge surface passes over the landing pattern. In addition, the discharge unit is moved in a direction opposite to the previously moved direction so that the discharge surface again passes over the landing pattern, and each of the landing patterns after the discharge unit has moved in both directions. Inspect from the shape of the droplet ,
In the landing state inspection mode, the discharge unit is moved a plurality of times in the both directions before the landing pattern is inspected. At that time, the movement in the both directions is completed and the next two directions are completed. A coating apparatus that performs a movement in a direction orthogonal to the scanning direction before performing the movement . The distance between the ejection surface and the inspection surface when moving the ejection unit in the landing state inspection mode is equal to or less than the distance between the ejection surface and the substrate when scanning the ejection unit in the coating mode. The coating apparatus according to claim 1, wherein: 3. The method according to claim 1, wherein when the landing pattern is formed in the landing state inspection mode, the discharge unit discharges a liquid droplet a plurality of times to an equivalent location on the inspection surface. A coating apparatus according to any one of the above. A discharge unit having a plurality of discharge nozzles for discharging droplets, each discharge nozzle being disposed on a discharge surface;
An inspection surface for landing droplets;
A moving mechanism for relatively moving the discharge unit and the inspection surface in a direction parallel to the inspection surface;
A landing state inspection method for a coating apparatus comprising:
A pattern forming step in which the discharge unit discharges droplets onto the inspection surface to form a landing pattern;
After the pattern formation step, the ejection unit is moved so that the ejection surface passes over the landing pattern, and then the previous movement direction so that the ejection surface passes again over the landing pattern. An inspection step of inspecting from the shape of each droplet of the landing pattern after the discharge unit is moved in the opposite direction and the discharge unit is moved in both directions;
I have a,
In the inspection step, before the landing pattern is inspected, the discharge unit is moved a plurality of times in both directions, and at that time, the movement in the both directions is completed and the next movement in the two directions is performed. A landing state inspection method characterized by performing movement in a direction orthogonal to the scanning direction before execution . In the inspection step, a distance between the ejection surface when moving the ejection unit and the inspection surface is equal to or less than a distance between the ejection surface and the substrate when scanning the ejection unit in the coating mode. The landing state inspection method according to claim 4 , wherein the landing state inspection method according to claim 4 . The said pattern formation process WHEREIN: When forming the said landing pattern, the said discharge unit discharges a droplet several times to the equivalent location on the said test | inspection surface, It is any one of Claim 4 or 5 characterized by the above-mentioned. The landing state inspection method described in 1.

Images