JP2008168207A - Inferior discharge detection device and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inferior discharge detection device for exactly and rapidly detecting a nozzle which causes the inferior discharge of a droplet using an inexpensive method, and also provide an inferior discharge detection method. <P>SOLUTION: The inferior discharge detection device 10 is provided with an ink jet head 11 for discharging the droplet to a base plate 2 through a nozzle 12. A first area 21 which has a shape in accordance with an area occupied by the landed state of the droplet on the base plate 2 and has a first wettability to the droplet and a second 22 which has a second wettability higher than a first wettability and is in contact with the first area 21 are formed at the surface of the base plate 2. The ink jet head 11 discharges the droplet to the first area 21 as a target. The inferior discharge detection device 10 is provided with a detection means 3 for detecting at least one of the shape and the position of the droplet in a state of contacting on the first area 21 and a determination means 66 which determines the quality of droplet discharge based on detection result by the detection means 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for forming a fine pattern on an object using an inkjet method. More specifically, the present invention relates to a discharge failure detection device and a discharge failure detection method for detecting a nozzle that has caused a discharge failure.

  In recent years, inkjet technology has been applied not only as a conventional technology for printing on paper media but also as a technology for forming a fine pattern on a substrate used as a display device member or circuit. Examples of the fine pattern formed on the substrate include a pixel of a color filter panel, an organic EL element that is a light emitting element, and a metal wiring of a circuit board. In order to apply the inkjet technique to a manufacturing apparatus for forming a fine pattern on a substrate, it is necessary to strictly control the ejection of droplets as compared with the case of using as a conventional printing technique.

  For example, since the material of the liquid droplet to be discharged is different for each type of product to be manufactured, the properties (viscosity and volatility) of the material of the liquid droplet to be discharged are also different. In order to impart desired functions and properties to the product, it may be necessary to select a material having high viscosity and high volatility. If a material with high viscosity or volatility is selected as the material of the droplets to be ejected, droplets will not be ejected compared to conventional printing inks (the droplets will not actually be ejected even if an ejection instruction is received). It is easy to happen. The non-ejection of the liquid droplets directly leads to a decrease in quality such as discontinuity and unevenness of the pattern on the object to which the liquid droplets are applied and an increase in the defective product rate.

  Further, it is necessary to form a much finer pattern on a medium such as a substrate as compared with the conventional pattern formation for printing on a paper medium. Since the fineness of the pattern formed on the medium affects the quality of the manufactured product and the yield rate, misalignment caused by variations in the flying angle of the droplets flying from the nozzle holes is allowed only in a small range. Can not do it. As an example of a manufacturing apparatus in which a product becomes defective due to the positional deviation of the droplets, a color filter manufacturing apparatus can be cited. The color filter is a filter in which a plurality of pixels are formed on a substrate. In the color filter, each of the plurality of pixels is colored with a single color, and the plurality of pixels are color-coded into three colors. When a droplet other than the desired color lands on a region where the pixel is formed due to the positional deviation of the droplet, the pixel is mixed. A color filter having pixels with mixed colors is a defective product that cannot display a clear image on a display device.

  As described above, ejection failure (non-ejection of droplets, ejection amount abnormality and displacement) is a major obstacle for forming a fine pattern. Therefore, when the inkjet technique is used for manufacturing a display device or the like, it is necessary to detect a nozzle that causes a droplet ejection failure before performing the ejection process. If a nozzle that causes non-ejection can be found, the quality of the product and the yield rate can be improved by performing a repair operation, not using a nozzle that causes ejection failure, or replacing the inkjet head.

  Japanese Patent Application Laid-Open No. H10-228707 discloses a method for manufacturing a color filter for detecting ejection failure of an inkjet head. The manufacturing method of the color filter of patent document 2 is a manufacturing method which detects the discharge defect of an inkjet head before coloring a pixel by performing preliminary discharge outside the formation area of the pixel in a color filter substrate. By imaging an area where the preliminary ejection has been performed using an area sensor such as a camera, non-ejection, ejection amount abnormality, and inkjet head positional deviation are detected.

Japanese Patent Application Laid-Open No. 2004-228688 discloses an ink discharge detection apparatus that can detect an abnormality in the amount of ink discharged from the discharge head and ink shortage without using recording paper. The ink discharge detection device of Patent Document 2 discharges ink from an ink discharge port to a reflecting plate having high water repellency and light reflectivity, and detects reflected light from the reflecting plate to detect abnormal ink discharge. It is a device to detect. Further, since the reflecting plate is provided with an inclination or provided with a reflecting plate rotating means for inclining or rotating the reflecting plate, the ink drops from the reflecting plate when the detection of the ink discharge abnormality is completed. Can be made.
JP-A-9-101410 (published on April 15, 1997) JP-A-8-332786 (published on December 17, 1996)

  However, in the method of Patent Document 1, since it is necessary to determine whether the ejection is good or not by acquiring two-dimensional data using an area sensor, it takes a lot of time to detect ejection failure. For example, the following processing is required to detect ejection failure, and the processing time becomes long. A region near each droplet landed on the substrate is imaged by a digital camera or the like. The captured image is converted into data by performing binarization processing separately for the landing site and the landing site of the droplet. The position and shape of the landed droplet are determined by deriving the gravity center value of the landed droplet using the binarized data. The quality of ejection is determined based on the position and shape of the landed droplet.

  Since it is necessary to perform complicated processing as described above, it takes time to detect ejection failure. There is a tendency to increase the number of nozzles provided in one manufacturing apparatus in order to shorten the tact time of the ejection process for the medium. Therefore, as the number of nozzles provided in the manufacturing apparatus is increased, the processing time for determining the quality of ejection for all the nozzles increases. It is difficult to simplify the detection of a nozzle that has caused a discharge failure from the viewpoint of improving product quality and yield rate. Therefore, simply increasing the number of nozzles may reduce the productivity of the apparatus.

  Furthermore, many processes are required for detecting a positional deviation and its degree with high accuracy, in particular, equipment necessary for imaging a substrate, acquiring data, and analyzing data. In order to speed up the ejection failure detection process, it is necessary to provide high-performance, that is, more expensive equipment. Naturally, the introduction of expensive equipment leads to an increase in product cost.

  As described above, when the method of Patent Document 1 is used, improving the processing speed for detecting ejection failure and reducing the cost of the product are problems that cannot be solved at the same time.

  Further, in the apparatus of Patent Document 2, it is possible to detect a non-ejection and an abnormality in the ejection amount without ejecting a droplet to the medium. Not considered. Furthermore, since the detection of each nozzle is the same as the method of Patent Document 1, the processing time can be shortened only by installing a plurality of the same devices. Considering that it is necessary to increase the number of devices as the number of nozzles increases, it is difficult to think that this solution is practical.

  As described above, with the conventional technology, it has been difficult to detect landing position deviation with high accuracy and efficiency by a simple and inexpensive method. In addition, it is expected that the performance and quality of products will be improved in the future. Product refinement is necessary to improve the performance and quality of products. Therefore, it is necessary to refine the pattern formed on the medium more than ever. In other words, it is necessary to realize the demands for detection accuracy of ejection failure, detection processing speed of ejection failure, product productivity, and product cost reduction at a higher level than ever. Technology development to detect non-ejection among discharge failures is progressing, but technology that efficiently detects the deviation of the landing position of droplets has problems to be solved such as processing speed, detection accuracy, and cost of the detection device. Many were difficult to realize. For this reason, it is desired to develop a technique capable of simultaneously detecting the deviation of the landing position and the non-ejection of the droplet.

  The present invention has been made in view of the above problems, and an object of the present invention is to use a simple and inexpensive method to efficiently form a fine pattern on a medium using an inkjet method. An object of the present invention is to provide a discharge failure detection device and a discharge failure detection method for accurately and rapidly detecting a nozzle that has caused a discharge failure of a droplet.

  In order to solve the above-described problems, an ejection failure detection apparatus according to the present invention includes an inkjet head that ejects droplets onto a substrate through a nozzle, and detects the quality of droplet ejection from the nozzle on the surface of the substrate. Is a shape corresponding to the area occupied by the droplets landed on the substrate, and has a first region having a first wettability with respect to the droplets, and a first region higher than the first wettability. And a second region in contact with the first region is formed. The inkjet head ejects liquid droplets targeting the first region, and the ejection failure detection device includes the first region. Detection means for detecting at least one of the shape and position of the liquid droplet in contact with the upper surface, and determination means for determining whether or not the liquid droplet is discharged based on a detection result by the detection means.

  By having the above-described configuration, when the droplet discharge is satisfactory, the droplet normally reaches the first region. On the other hand, when the droplet discharged from the nozzle is displaced, the droplet that has landed on the substrate is likely to come into contact with a portion other than the first region. Here, when the droplet comes into contact with the second region in contact with the first region, as compared with the droplet that is stationary on the first region, the droplet that has caused the displacement causes a change in shape, And it stops at a position far away from the center of the first region.

  Therefore, for example, the detection means detects the height of the droplet, and the determination means compares the detected height with the height when the droplet has successfully landed on the first region. Thus, it is possible to determine whether the droplet discharge is good or bad.

  This is because the wettability with respect to the droplet is higher in the second region than in the first region, and thus the droplet that has caused the landing position deviation is easily pulled to the second region. That is, when the degree of the positional deviation of the droplets is the same, the droplets that have landed in the substrate according to the present invention cause a change in shape as compared with the conventional substrate having uniform wettability, and the liquid The movement distance of the droplet from the center of the first region is increased. In other words, it can be said that the landing position deviation of the droplet can be amplified in terms of the shape change of the droplet and the movement distance from the center of the first region.

  Therefore, it is possible to detect a nozzle that has caused a droplet ejection failure (landing position deviation and non-ejection) using a simple and inexpensive detection means without using equipment that is highly sensitive but expensive as in the past. .

  That is, there is an effect that the nozzle that has caused the ejection failure can be easily and quickly detected using low-cost equipment.

  In the ejection failure detection device of the present invention, it is preferable that a contact angle between the droplet and the first region when the droplet is stationary on the first region is 50 ° to 90 °.

  By having the above configuration, the wettability in the first region is reduced (the droplet is easily repelled), so that the droplet is more easily pulled to the second region. That is, it is possible to further increase the shape change of the droplet that has caused the landing position shift and the movement distance from the center of the first region.

  Therefore, there is an effect that it is possible to more easily and rapidly detect the nozzle that has caused the ejection failure.

  Further, in the ejection failure detection device of the present invention, the contact angle between the droplet and the first region when the droplet is stationary on the first region, and the droplet is stationary on the second region The difference between the contact angle formed by the droplet and the second region in the state is preferably 40 ° or more.

  By having the above configuration, the difference in wettability between the first region and the second region is sufficiently large (droplets are easily pulled from the first region to the second region). That is, it is possible to sufficiently increase the shape change of the droplet that caused the landing position deviation and the movement distance from the center of the first region.

  Therefore, there is an effect that the detection accuracy of the nozzle that has caused the ejection failure can be further improved.

  In the ejection failure detection device of the present invention, the first region may be substantially circular.

  By having said structure, a 2nd area | region can be made to contact a 1st area | region from which direction. That is, regardless of the direction in which the droplet is displaced, the displacement can be detected.

  Therefore, it is possible to further improve the detection accuracy of the nozzle that has caused the ejection failure.

  In the ejection failure detection device of the present invention, the plurality of first regions may be formed at equal intervals on a straight line perpendicular to the moving direction of the substrate as viewed from the inkjet head.

  For example, ejection failure detection by the ejection failure detection device is performed by scanning an inkjet head or a substrate. That is, the moving direction of the substrate viewed from the inkjet head means a relative scanning direction between the inkjet head and the substrate.

  By having the above-described configuration, it is possible to detect nozzles that have caused ejection defects ejected from a plurality of nozzles provided in a plurality of inkjet heads at a time.

  Therefore, it is possible to detect a nozzle that has caused a discharge failure at a higher speed.

  In the ejection failure detection device of the present invention, it is preferable that the first area is surrounded by the second area.

  By having the above configuration, it is possible to detect the positional deviation of the liquid droplets in all directions of 360 ° as seen from the center of the first region by one landing of the liquid droplets.

  Therefore, it is possible to detect the nozzle that has caused the ejection failure more accurately and at high speed.

  In the ejection defect detection device of the present invention, the first region may be strip-shaped, and the long side direction of the first region may be parallel to the scanning direction of the substrate.

  By having the above configuration, it is possible to distinguish between a landing position deviation with respect to a direction parallel to the substrate scanning direction and a landing position deviation with respect to a direction perpendicular to the substrate scanning direction. Particularly, the landing position deviation with respect to the direction parallel to the scanning direction of the substrate occurs on a region where the wettability does not change. That is, the shape of the droplet does not change.

  The landing position deviation in the scanning direction of the substrate can be corrected by adjusting the discharge timing from the nozzle. Of the nozzles in which the ejection failure has occurred, the repairing operation of the nozzle that can correct the landing position by adjusting the ejection timing can be omitted.

  Therefore, it is possible to detect a nozzle that has caused a discharge failure at a higher speed.

  In the ejection defect detection device of the present invention, each of the plurality of first regions may be arranged at equal intervals and in parallel.

  By having the said structure, the quality of discharge of many nozzles can be determined at once.

  Therefore, the ejection failure can be detected at a higher speed.

  In the ejection failure detection device of the present invention, it is preferable that two long sides of the first region are in contact with the second region.

  By having the above configuration, it is possible to detect a liquid droplet that has been displaced toward the outside of the long side of the first region with a single landing.

  Therefore, it is possible to detect a nozzle that has caused a discharge failure at a higher speed.

  In the ejection failure detection device of the present invention, the normal direction of the substrate surface on which the first region and the second region are formed substantially coincides with the direction opposite to the direction of gravity, and the first region is It is preferable to protrude from the second region.

  By having the above configuration, an attractive force (gravity) is further applied as a force for pulling the droplet from the first region to the second region. In addition, the backflow of the droplet from the second region to the first region is less likely to occur due to the reaction at the time of landing. Therefore, the shape change of the droplet caused by the positional deviation of the droplet and the moving distance from the center of the first region can be increased.

  Therefore, there is an effect that the detection accuracy of the nozzle that has caused the ejection failure can be further improved.

  In the ejection failure detection device of the present invention, it is preferable that water absorption is provided near the boundary between the second region and the first region.

  By having the above configuration, the liquid droplets pulled to the second region can be absorbed in the vicinity of the boundary between the first region and the second region. Therefore, the shape change caused by the landing position deviation of the droplet and the distance from the first region can be increased. In particular, the height of the remaining absorbed liquid droplets becomes extremely small, so it becomes easy to determine whether or not the nozzle has caused a discharge failure based on the height of the liquid droplets.

  Therefore, there is an effect that the detection accuracy of the nozzle that has caused the ejection failure can be further improved.

  Further, in the ejection failure detection device of the present invention, the detection means includes a first sensor, and the first sensor detects an unevenness at the center of the first region in the substrate surface.

  As described above, the shape (particularly the height) of the liquid droplet that has caused ejection failure changes greatly in comparison with the liquid droplet that has been ejected normally. According to the above configuration, the detection unit can detect the ejection failure of the nozzle based on the height of the droplet on the substrate. That is, it is possible to detect ejection failure using a parameter that is easy to compare, such as comparing the height of a droplet that has landed normally and the height of a droplet that has caused ejection failure (non-ejection and misalignment). . For this reason, it is easy to determine the quality of the discharge, and the detection accuracy can be improved by using a simple detection means.

  Furthermore, if the sensor can detect the unevenness on the substrate, the height of the droplet that has landed on the first region can be easily detected. For example, as a sensor that can detect unevenness on a substrate, a displacement sensor that detects a displacement in height, a sensor that measures the reflectance of light of an object, and the like can be used. That is, it is possible to detect a discharge failure using an inexpensive detection sensor as the detection means.

  Therefore, it is possible to reduce the cost and improve the detection accuracy of the ejection failure detection device.

  In the ejection failure detection apparatus of the present invention, the detection means includes a first sensor, and the first sensor detects irregularities on the substrate surface while scanning so as to pass right above the center of the first region. May be.

  By having the above-described configuration, the detection unit can detect the height and positional deviation of a plurality of liquid droplets that are stationary on the substrate in a single scan.

  Therefore, there is an effect that it is possible to more easily and rapidly detect the nozzle that has caused the ejection failure.

  Further, in the ejection failure detection device of the present invention, the detection means further includes a second sensor, and the second sensor is a region on the substrate to be detected based on the unevenness of the substrate surface detected by the first sensor. And the shape of the droplet, the moving distance from the center of the first region, and the moving direction from the center of the first region may be detected.

  By having the above configuration, it is possible to further detect the direction of the positional deviation of the droplet and the distance from the center of the first region.

  Therefore, there is an effect that it is possible to accurately correct the nozzle that has caused the positional deviation.

  In the ejection failure detection device of the present invention, the substrate may further include a region for forming a desired pattern by ejecting the droplets.

  By having the above-described configuration, it is possible to continuously detect a nozzle that has caused an ejection failure and form a desired pattern.

  Therefore, there is an effect that the productivity of the product can be increased.

  In order to solve the above-described problem, the discharge failure detection method of the present invention uses a nozzle formed on an ink jet head to cause a droplet to land on a substrate, thereby detecting whether or not the nozzle is discharged. And a first region having a first wettability with respect to the droplet, and a second region having a second wettability higher than the first wettability in contact with the first region A step of ejecting droplets to the substrate with the first region as a target, a step of detecting at least one of the shape and position of the droplet in contact with the first region, and detection And a step of determining the quality of discharge based on the result.

  By having said structure, there can exist an effect similar to the said ejection defect detection apparatus.

  As described above, the present invention is an ejection failure detection device that detects whether or not a nozzle is ejected by landing droplets on a substrate using a nozzle formed on an inkjet head, and is provided on the surface of the substrate. Has a shape matching the nozzle, a first region having a first wettability with respect to the droplet, and a second wettability higher than the first wettability in contact with the first region. Two regions are formed, and detecting means for detecting the shape or position of the droplet contacting the first region formed on the substrate surface, and the nozzle based on the shape or position of the droplet Determination means for determining whether or not the discharge is good. Therefore, it is possible to detect a nozzle that has caused a droplet ejection failure (landing position deviation and non-ejection) using a simple and inexpensive detection means without using equipment that is highly sensitive but expensive as in the past. . In other words, there is an effect that a nozzle that has caused a droplet ejection failure can be detected easily and at high speed using low-cost equipment.

  Embodiments according to the present invention will be described with reference to FIGS. In the following description, the same members and components are denoted by the same reference numerals. The names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
A configuration of a discharge failure detection apparatus 10 according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram showing a device configuration of a discharge failure detection device 10 according to an embodiment. As shown in FIG. 1, the ejection failure detection apparatus 10 includes an inkjet head unit 1, detection means 3, a substrate stage 4 on which a substrate 2 is placed, a mark sensor 5, and a computer 6.

  The ink jet head unit 1 is composed of three ink jet heads 11 each having a plurality of nozzles 12 formed therein. Each of the inkjet heads 11R, 11G, and 11B is an inkjet head 11 for ejecting ink of any one color of red (R), green (G), and blue (B).

  A liquid repellent area 21 as a first area, a non-liquid repellent area 22 as a second area, and an alignment mark 23 are formed on the landing surface of the substrate 2 placed on the substrate stage 4. The liquid repellent region 21 is formed as a plurality of island-shaped regions having a substantially circular shape, and is surrounded by the non-liquid repellent region 22. The center point of the island-shaped region constituting the liquid repellent region 21 is the normal landing position of the droplet discharged from the nozzle 12. The alignment mark 23 is a mark used for adjusting the direction of the substrate 2 and positioning (alignment) between the liquid repellent region 21 and the nozzle 12, and is formed of a material different from the material forming the substrate 2.

  The detection means 3 includes three sensors 31 for detecting the height of the object on the substrate 2 (distance in the Z-axis direction), and three imaging cameras 32 for imaging the landing surface of the substrate 2 (see FIG. 2 (a)). That is, the same number of sensors 31 and imaging cameras 32 as the inkjet heads 11 are provided. Furthermore, the detection means 3 is connected to a scanning means for moving the detection means 3 in the X-axis direction (see FIG. 2B).

  The substrate stage 4 includes a substrate holding table 41 for holding the substrate 2 by vacuum suction, a linear scale 42 used for measuring the moving distance of the substrate holding table 41, and a linear encoder 43 that reads the moving distance of the substrate holding table 41. Has been. The substrate stage 4 is further provided with substrate transport means (not shown) for translating the substrate holding table 41 in the Y-axis direction.

  The ejection failure detection device 10 of the present embodiment has a configuration in which the substrate 2 is moved in the Y-axis direction using the substrate stage 4 while the inkjet head unit 1 is stationary. However, the configuration is not limited to the above configuration, and the inkjet head unit 1 may be moved in the Y-axis direction using a conventionally known driving unit while the substrate 2 is stationary.

  The mark sensor 5 is a sensor for recognizing that the alignment mark 23 has arrived immediately below it, and is a sensor for detecting an angle shift of the substrate 2 and the like.

  The computer 6 is connected to the inkjet head unit 1, the detection means 3, the substrate stage 4 and the mark sensor 5. The computer 6 controls the operations of the inkjet head 11, the detection unit 3 and the substrate stage 4 based on information sent from the detection unit 3, the substrate stage 4 and / or the mark sensor 5. In addition, the computer 6 includes a determination unit 66 that determines whether or not the nozzle 12 is ejected based on the shape or position of the droplet on the substrate surface detected by the detection unit 3.

  FIG. 2A is a plan view showing the main part of the ejection failure detection apparatus 10 according to this embodiment, and FIG. 2B is a side view showing the configuration of the detection means 3.

(Liquid-repellent region 21 and non-liquid-repellent region 22)
As shown in FIG. 2A, twelve perfect liquid-repellent regions 21 are formed on the landing surface of the substrate 2, and the twelve liquid-repellent regions 21 are arranged in three rows and four columns. ing. The four liquid-repellent regions 21 forming one row are arranged so that the centers 24 thereof are arranged in parallel with the X axis with an interval of W1 (here, 200 μm). Further, the three liquid repellent regions 21 in a row have intervals of W2 (here, 500 μm) at the center 24 thereof on one line segment (for example, line segment AA ′) parallel to the Y axis. It is arranged to line up with a gap.

  Since the liquid repellent region 21 in the present embodiment is formed in a perfect circle shape, even if the liquid droplet is displaced in any direction (360 degrees), the liquid droplet It is possible to detect a discharge failure of the nozzle 12 that has discharged the gas.

  The liquid repellent region 21 is a wettable region that exhibits liquid repellency with respect to the droplets ejected from the nozzle 12. The contact angle of the droplet with respect to the liquid repellent region 21 representing the wettability of the liquid repellent region 21 is preferably 50 to 90 °, and more preferably 60 to 80 °.

  When the contact angle of the droplet with respect to the liquid repellent region 21 exceeds 90 °, even a droplet that has landed normally is likely to be repelled by the liquid repellent region 21. Further, the droplets are easily slid on the liquid repellent region 21 due to external influences (disturbances) such as airflow and vibration. For this reason, a part of the droplets that have landed normally easily come into contact with the non-liquid-repellent region 22, thereby reducing the detection accuracy of ejection failure. Further, when the contact angle of the droplet with respect to the liquid repellent region 21 is less than 50 °, the difference from the contact angle of the droplet with respect to the non-liquid repellent region 22 becomes small. Therefore, since the amount of the liquid droplet that has been displaced moves to the non-liquid-repellent region 22 is reduced, the detection accuracy of ejection failure is lowered, and the detection speed is hindered.

  In order to form the liquid repellent area 21, liquid repellency with respect to droplets ejected from the nozzles 12 may be imparted to a desired area on the substrate 2. In order to impart liquid repellency to the substrate 2, a conventionally known method may be selected according to the material of the substrate 2 used. As a conventionally known method for imparting the liquid repellency to the liquid repellent region 21, a method of forming a water repellent film on the substrate 2 can be mentioned. As a method of forming a water repellent film on the substrate 2, for example, a method of applying a liquid containing a fluorine-based material to a desired region on the substrate 2 made of glass and then solidifying the liquid by heating. Can be mentioned. Further, when the liquid repellent region 21 is formed on the surface made of polyimide, the polyimide film may be subjected to microwave plasma treatment.

  The non-liquid repellent area 22 is an area having a wettability higher than the wettability of the liquid repellent area 21. It is preferable that the contact angle of the droplets with respect to the non-liquid-repellent region 22 representing the wettability of the non-liquid-repellent region 22 is 5 to 30 °. The reason why it is preferable that the contact angle representing the wettability of the non-liquid-repellent region 22 is in the above range will be described in Examples described later.

  In order to form the non-liquid-repellent region 22 having wettability expressed as a contact angle of 5 to 30 °, an ashing process may be performed on a desired region of the substrate 2 made of glass. The contact angle can be changed by changing the conditions of the ashing process. Other than the methods listed here, a conventionally known method that can form the non-liquid-repellent region 22 having the desired wettability can be employed.

  The contact angle representing the wettability of the liquid repellent region 21 and the non-liquid repellent region 22 may be measured using a conventionally known contact angle measuring method or apparatus.

  In the present embodiment, the diameter of the region where the droplet contacts the substrate 2 is 36 μm, and the diameter of the perfect liquid repellent region 21 is 40 μm. Here, the diameter of the perfectly circular liquid-repellent region 21 is an area (substantially circular region) where the droplets that are normally ejected from the nozzle 12 come into contact with the substrate 2 after landing on the substrate 2. Greater than diameter. The diameter of the liquid repellent region 21 is proportional to the droplet amount of the droplet, the size of the contact angle of the droplet with respect to the liquid repellent region 21, and the allowable amount of positional deviation of the droplet. What is necessary is just to set so that a droplet may become larger than the diameter of the area | region which contacts the board | substrate 2. FIG.

  The diameter of the perfectly circular liquid-repellent region 21 is preferably 3 to 10 μm larger than the diameter of the region where the droplet contacts the substrate 2. If it is below the above range, even if it can be considered that the droplet has successfully landed, the possibility that a part of the droplet will come into contact with the non-liquid-repellent region 22 is increased. As a result, the number of nozzles 12 determined to be defective in discharge increases. That is, the detection accuracy of the ejection failure is lowered, and the time required for the repair process of the nozzle 12 causing the ejection failure is increased.

  The difference between the contact angle of the droplet with respect to the liquid repellent region 21 and the contact angle of the droplet with respect to the non-liquid repellent region 22 is preferably 40 ° or more. When the difference between the contact angle of the droplet with respect to the liquid-repellent region 21 and the contact angle of the droplet with respect to the non-liquid-repellent region 22 is less than 40 °, The difference between the two becomes smaller. Accordingly, since the amount of droplets that have undergone misalignment moves to the non-liquid-repellent region 22, it becomes impossible to detect the quality of ejection using a simple method.

  Water absorption is preferably provided near the boundary between the non-liquid-repellent region 22 and the liquid-repellent region 21. For example, the material of the non-liquid repellent region 22 that forms the periphery of the liquid repellent region 21 may be a porous material such as a vinyl alcohol resin. Most of the droplets that have partially landed on the non-liquid-repellent region 22 due to the displacement are absorbed by the non-liquid-repellent region 22. Therefore, it is possible to more accurately detect the nozzle 21 that has caused landing deviation.

(Mark sensor 5 and alignment mark 23)
Two alignment marks 23 are further formed on the substrate 2. Each of the two alignment marks 23 is detected by each of the two mark sensors 5.

  The positional relationship on the substrate 2 between the two alignment marks 23 and the liquid repellent region 21 is determined in advance. An example of the positional relationship between the two alignment marks 23 and the liquid repellent area 21 is shown below.

  For example, the two alignment marks 23 are arranged in parallel to the X axis. That is, the two alignment marks 23 are arranged in parallel with the four liquid repellent regions 21 forming one line. For example, the centers of the two alignment marks 23 are arranged on a line segment CC ′ or DD ′ that is in contact with the boundary between the liquid repellent area 21 and the non-liquid repellent area 22 located at both ends of the three rows. ing. If the alignment mark 23 and the liquid repellent area 21 are arranged on the substrate 2 as described above, the position of the liquid repellent area 21 on the substrate 2 is detected by detecting the positional relationship between the two alignment marks 23. can do.

  Next, an example of a method for detecting the alignment mark 23 by the mark sensor 5 will be described. For example, the two alignment marks 23 are imaged using two cameras (not shown) arranged at the same interval as the two alignment marks 23 and parallel to the X-axis direction. The positional relationship between the two imaged alignment marks 23 is detected. When the positional relationship is detected, it is determined whether or not the two alignment marks 23 are arranged in parallel, and whether or not each of the two alignment marks 23 is rotated due to a shift in the direction of the substrate 2. Is to detect.

  Based on the detected positional relationship, the direction of the substrate 2 is corrected and the position of the liquid repellent region 21 is determined. Specifically, by using a substrate direction adjusting unit (not shown) formed in the substrate stage 4, the substrate 2 is moved in parallel in the X-axis direction, the Y-axis direction, and / or rotationally moved, thereby the line segment B The direction of the substrate 2 is adjusted so that the line segment AA ′ passes directly below −B ′. Further, the position of the liquid repellent area 21 on the substrate 2 is grasped based on the positional relationship between the two imaged alignment marks 23 and the arrangement of the alignment mark 23 and the liquid repellent area 21.

  Here, an example of the arrangement of the alignment mark 23 and the liquid repellent region 21 on the substrate 2 has been described. Not only the alignment adjustment of the substrate 2 using the alignment mark 23 and the camera, but also a conventionally known method and apparatus as long as the adjustment of the direction of the substrate 2 and the position of the liquid repellent region 21 can be appropriately performed as described above. Can be adopted.

  For example, the alignment mark 23 is a region (metal mark) made of metal formed on the glass substrate 2, and the mark sensor 5 is a reflective fiber sensor. In this case, the mark sensor 5 detects the presence of the alignment mark 23 by detecting a difference in reflectance between glass and metal.

  Based on the distance from the mark sensor 5 to each nozzle 12 and the position of the liquid repellent region 21 on the substrate 2, the timing for ejecting droplets from each nozzle 12 is determined.

(Injection head 11 and nozzle 12)
In each of the inkjet heads 11R, 11G, and 11B constituting the inkjet head unit 1, a plurality of nozzles 12 arranged in a straight line are arranged at a pitch of W3 (here, 210 μm).

  In addition, in each of the inkjet heads 11R, 11G, and 11B, the angle is adjusted so that each of the plurality of nozzles 12 has an interval of W1 with respect to the X-axis direction. Further, the inkjet heads 11R, 11G, and 11B are adjusted so that three of the nozzles 12 included in each of the inkjet heads 11R, 11G, and 11B are aligned on one line segment (for example, a line segment B-B ′).

  Here, the inkjet heads 11R, 11G, and 11B are adjusted so that the arrangement of the nozzles 12 forms an angle of 80 ° with respect to the Y axis. The inkjet heads 11R, 11G, and 11B are fixed to a unit holding member (not shown).

  As described above, the substrate 2 is fixed to the substrate stage 4 provided with the substrate transporting means by vacuum suction. By using the substrate transporting means, the substrate 2 can be moved in parallel (sliding) just below the inkjet head unit 1.

  Therefore, by moving the substrate 2 in the Y-axis direction, three nozzles 12 in which any one of the four liquid repellent areas are arranged on one line segment (for example, line segment BB ′) are arranged. Pass directly under.

(Detector 3)
The detector 3 will be described below with reference to FIG. FIG. 2B is a side view of the ejection failure detection device 10 as viewed from the direction opposite to the Y direction in FIG.

  As shown in FIG. 2B, the detector 3 can image a part of the area on the substrate 2 and the sensor 31 that is the first sensor for detecting the height of the object. An imaging camera 32 as a sensor is provided. The sensor 31 and the imaging camera 32 are installed such that the respective detection units and imaging unit and the landing surface of the substrate 2 face each other. Further, the detector 3 is movable in the X-axis direction by using a rail 33 connected to the slide beam 34.

  For example, the sensor 31 may include a displacement sensor that detects displacement using a laser system. By detecting the height difference using the displacement sensor while the detector 3 is translated on the substrate 2 in the X-axis direction, the droplet 7 that has landed on the substrate 2 exists on the liquid repellent region 21. Whether or not the shape of the droplet on the liquid repellent region 21 can be detected. For example, examples of the imaging camera 32 include a camera in which a magnifying lens is attached to a digital camera having a CCD element. By using the above camera, a desired area on the substrate 2 (such as an area including a portion where the liquid droplet 7 does not exist on the liquid repellent area 21 by the sensor 31 or a shape change is detected but detected). Images can be acquired. The shape of the droplet 7 landed on the image acquired by the camera using a conventionally known image processing technique and the distance from the center 24 of the liquid repellent region 21 can be specified.

  Even if the sensor is other than the exemplified displacement sensor, any sensor can be used as long as it can detect the presence or absence of the droplet 7 on the liquid repellent region 21 by translating the substrate 2 in the X-axis direction. It can be used as the sensor 31.

(Substrate stage 4)
As described above, the substrate stage 4 includes the substrate holding table 41, the linear scale 42, and the linear encoder 43. A high-precision glass scale is used as the linear scale 42. The substrate stage 4 is further provided with substrate transport means for translating the substrate holding table 41 in the Y-axis direction. Further, the substrate stage 4 is connected to a computer 6.

  By operating the substrate transfer means under the control of the computer 6, the substrate 2 can be moved at an arbitrary speed and can be stopped at an arbitrary position. The position of the substrate 2 is recognized by transmitting and processing the position information (the linear encoder 43 output value measured using the linear scale 42) of the substrate 2 and the substrate holder 4 to the computer 6 in real time.

(Substrate 2 on which droplets land)
The state of the substrate 2 after the droplets have landed will be described with reference to FIG. FIG. 3 is a partial plan view of the ejection failure detection device 10, and is a plan view of the substrate 2 and the detector 3 after the droplets are landed as viewed from the direction opposite to the Z direction in FIG. 2. .

  As shown in FIG. 3, the droplet 71 that has landed near the center 24 of the liquid repellent region 21 remains on the liquid repellent region 21. However, all or a part of the landed droplets (droplets 72a and 72b, droplets 73a and 73b, and droplet 74) that have been displaced have moved to the second region. Each of the sensors 31a, 31b and 31c has three line segments (line segments EE ′, F) connecting the centers 24 of the four liquid repellent areas 21 out of the 12 liquid repellent areas 21 formed on the substrate 2. -F 'and GG').

  Regardless of the detection using any of the sensors 31a, 31b and 31c, the droplet 71 is detected as a shape having one mountain and existing on the liquid repellent region 21.

  When detected using the sensor 31a, the droplet 72a is detected as a shape that is present on the line segment EE ′ and on the liquid repellent region 21 and has a lower height and a narrower width than the droplet 71. The When detected using the sensor 31a, the droplet 72b is present on the line segment EE ′ and on the non-liquid-repellent region 22 and has a height lower than that of the droplet 71 and the same width. Detected as a shape. In addition, the droplets 72a and 72b discharged from one nozzle 12 are detected as a shape having two peaks and one valley.

  When detected using the sensor 31b, the droplet 73a is present on a part of the line segment FF ′ and on the liquid-repellent region 21, and is very low in height as compared with the droplet 71. It is detected as a narrow shape. When detected using the sensor 31b, the droplet 73b is not detected.

  When detected using the sensor 31c, the droplet 74 is present on the line segment GG ′ and on the non-liquid-repellent region 22 and is detected as a shape having a lower height and a wider width than the droplet 71. Is done.

  As described above, the liquid droplets (liquid droplets 72 a and 72 b, liquid droplets 73 a and 73 b, and liquid droplet 73) that have been displaced are compared with the liquid droplet 71 that has landed on the center 24 of the liquid repellent region 21. The shapes (height and width) are significantly different.

  Based on the detection results of the three sensors 31, the sensor 32 images a region on the substrate 2 centered on the droplets 72 a and 72 b, the droplets 73 a and 73 b, and the liquid repellent region 21 closest to the droplet 73. .

(Determination means 66)
As described above, the computer 6 includes the determination unit 66. The determination unit 66 determines the quality of ejection from each nozzle 12 based on the shape or position of the droplet on the substrate 2 obtained by the detector 3 (three sensors 31 and 32). That is, a nozzle that ejects a droplet that has undergone a change in shape compared to the droplet 71 that is in contact only with the liquid-repellent region 21 or a portion of the droplet that is in contact with the non-liquid-repellent region 22 is discharged. Judge as bad.

  As described above, by using the detector 3, particularly the sensor 31, it is possible to easily detect the position and shape of the droplet that has landed on the substrate 2. Therefore, it is possible to easily detect a nozzle ejection failure using the determination unit 66.

[Embodiment 2]
A modification of the ejection failure detection device 10 of the first embodiment will be described with reference to FIG. 4A is a plan view of the substrate 2 according to the present embodiment, and FIG. 4B is a direction opposite to the Z direction in FIG. 2 with respect to the substrate 2 and the detector 3 after the droplets have landed. It is the top view seen from.

  As shown in FIG. 4A, a plurality of liquid repellent areas 21 and a non-liquid repellent area 22 surrounding the plurality of liquid repellent areas 21 are formed on the substrate 2.

  The liquid repellent region 21 is formed as a rectangular shape having long sides extending in the Y-axis direction. The liquid repellent region 21 includes three midpoints 25, and a line connecting the three midpoints 25 overlaps a line segment H-H 'that bisects the liquid repellent region 21 in the X-axis direction. That is, when the substrate 2 is moved in the Y-axis direction, the line segment BB ′ (the trajectory through which the plurality of nozzles 12 in FIG. 2A passes) passes directly above the line segment HH ′. .

  The length of the liquid repellent region 21 in the X axis direction is 40 μm, and the length of the liquid repellent region 21 in the Y axis direction is 200 μm. In this embodiment, the diameter of the droplet is 36 μm and the length of the liquid repellent region 21 in the X-axis direction is 40 μm. The droplet contacts the non-liquid repellent area 22. On the other hand, a droplet that has caused a positional deviation within a range allowed for normal ejection in the X-axis direction does not contact the non-liquid-repellent region 22. Therefore, it is possible to detect ejection defects with high accuracy.

  Further, since the length of the liquid repellent region 21 in the Y-axis direction is 200 μm, a droplet that has been displaced in the Y-axis direction does not come into contact with the non-liquid repellent region 22. Therefore, unlike the positional deviation with respect to the X-axis direction, the liquid droplet of the landed droplet that occurs when the droplet contacts the non-liquid-repellent region 22 and the distance from the midpoint 25 do not increase. The positional deviation with respect to the Y-axis direction can be corrected by adjusting the ejection timing. The liquid repellent region 21 according to the present embodiment is long in the Y-axis direction in order to correct the ejection timing accurately by measuring the distance between the liquid droplet that has been displaced in the Y-axis direction and the midpoint 25. It is formed as a shape having sides. See Embodiment 1 for the method of measuring the distance between the misaligned droplet and the center of the liquid repellent region 21.

  Adjacent liquid repellent areas 21 have two line segments that divide each of the liquid repellent areas 21 in the X-axis direction by 200 μm. This coincides with the interval in the X-axis direction between two adjacent nozzles 12 formed in the inkjet head 11. Therefore, it is possible to reliably land droplets normally ejected from the plurality of nozzles 12 formed on the inkjet head 11 on the liquid repellent region 21.

  As shown in FIG. 4B, the droplet 7 that has landed near the midpoint 25 of the liquid repellent area 21 remains on the liquid repellent area 21. However, in the droplets 72 a and 72 b and the droplet 74 that have been displaced in the X-axis direction, some or all of the landed droplets have moved to the non-liquid-repellent region 22. The droplet 73 that has been displaced in the Y-axis direction is stationary on the liquid repellent region 21. Each of the sensors 31a, 31b, and 31c includes three line segments (line segments II ′, I ′ ′) connecting the midpoints 25 of the four liquid repellent areas 21 among the 12 liquid repellent areas 21 formed on the substrate 2. It passes directly above any one of the line segment JJ ′ and the line segment KK ′).

  Regardless of the detection using any of the sensors 31a, 31b and 31c, the droplet 71 is detected as a shape having one mountain and existing on the liquid repellent region 21.

  When detected using the sensor 31a, the droplet 72a is detected as a shape having a lower height and a narrower width than the droplet 71, which is present on the line segment II ′ and the liquid repellent region 21. The When detected using the sensor 31a, the droplet 72b is present on the line segment II ′ and on the non-liquid-repellent region 22 and has a height lower than that of the droplet 7 and the same width. Detected as a shape. Further, the droplets 72a and 72b discharged from one nozzle 12 are detected as a shape having two peaks and one valley.

  When detected using the sensor 31b, the droplet 73 is present on a part of the line segment JJ ′ and on the liquid repellent region 21, and is very low in height compared to the droplet 71, and very much. It is detected as a narrow shape.

  When detected using the sensor 31c, the droplet 74 is present on the line segment KK ′ and on the non-liquid-repellent region 22, and is detected as a shape having a lower height and a wider width than the droplet 7. Is done.

  As described above, the position-shifted droplets (droplets 72a and 72b, droplet 73 and droplet 73) have a shape ( The height and width are significantly different.

  As described above, the positional deviation in the Y-axis direction can be corrected by correcting the timing of ejection from the nozzle 12. In order to accurately adjust the discharge timing, the sensor 32 is used to detect the distance from the midpoint 25 of the liquid-repellent region 21 of the liquid droplet 21 that has been displaced.

  Based on the detection results of the three sensors 31, the sensor 32 images a region on the substrate 2 around the liquid repellent region 21 closest to the droplets 72 a and 72 b, the droplet 73 a and the droplet 73.

  Based on the detection results of the sensors 31 and 32, the determination unit 66 determines whether or not the liquid droplets are discharged. See Embodiment 1 for details.

[Embodiment 3]
A discharge failure detection method using the discharge failure detection apparatus 10 according to the first and second embodiments will be described with reference to FIGS. FIG. 5 is a flowchart for explaining the processing procedure of the ejection failure detection apparatus 10. FIG. 6 is a side view illustrating the alignment processing of the substrate 2 by the ejection failure detection device 10. FIG. 7 is a side view illustrating the discharge process of droplets onto the substrate 2 by the discharge failure detection device 10. FIG. 8 is a side view illustrating a process for detecting the position and shape of a droplet landed on the substrate 2 by the ejection failure detection device 10.

  The ejection failure detection device 10 constitutes a part of an inkjet manufacturing device, and the computer 6 that controls the operation of the manufacturing device also controls the operation of the ejection failure detection device 10 at the same time. That is, the ejection failure detection of the nozzle 12 using the ejection failure detection device 10 is one process included in the manufacturing process of the manufacturing apparatus.

  The control unit 65 inside the computer 6 shared by the manufacturing apparatus and the ejection failure detection device 10 receives the signal that the preparation for detecting ejection failure of the inkjet head 11 is completed, and thereby the substrate 2 is carried onto the substrate stage 4. (Step S1).

  The above-mentioned signal that preparation for detection of ejection failure is completed is, for example, a signal that is input to the control unit 65 when ejection of droplets onto a production substrate is completed, and a production apparatus for a new production substrate. For example, a signal for instructing the ejection of the used droplets. The substrate 2 is carried in by a substrate carrying robot (not shown) in accordance with an operation instruction signal from the control unit 65 that has received the signal. The loaded substrate 2 is fixed to the substrate holding table 41 by vacuum suction. Note that, when the substrate 2 and the substrate for manufacturing are integrally formed, the substrate 2 is already loaded and fixed on the substrate holding base 41, and therefore the step S1 is not necessary.

  Next, the alignment mark 23 formed on the substrate 2 is adjusted and detected with respect to the nozzle hole by using the alignment camera system (not shown) provided in the ejection failure detection device 10 to adjust the direction of the substrate 2. The discharge detection substrate is positioned (step S2).

  The alignment mark 23 is imaged by the camera. Based on the captured image, the direction of the substrate 2 is detected from the positional relationship of the alignment marks 23. The direction fine adjustment unit provided on the substrate stage 4 (a structure in which the substrate 2 is moved in the X-axis direction and the Y-axis direction and the substrate 2 is rotated while the normal direction of the substrate 2 is maintained) is rotated. Adjust the direction. As described in the first embodiment, the alignment mark 23 and the liquid repellent region 21 have a desired positional relationship. For this reason, by adjusting the direction of the substrate 2, the position of the liquid repellent region 21 relative to the nozzle 12 of the inkjet head 11 can be determined.

  The position determination is to adjust the direction of the substrate 2 by moving the substrate 2 in the Y-axis direction so that the line segment AA ′ passes directly under the line segment BB ′ ( (See FIG. 2 (a)).

  In order to reliably perform the position determination, it is preferable to measure in advance the positional relationship between the alignment mark 23 on the substrate 2 and the line segment A-A ′. Furthermore, in order to check the position of the substrate 2 through which the nozzle 12 passes, it is preferable to confirm the landing position by discharging droplets onto the dummy substrate on which the alignment mark 23 is formed.

  After adjusting the direction of the substrate 2, the substrate stage 4 holding the substrate 2 is moved directly below the head unit 1 and the detector 3 (step S4). Moving toward the position immediately below the head unit 1 and the detector 3 means moving in the Y-axis direction in FIG. 2A and moving in a direction parallel to the line segments AA ′ and BB ′. It is to let you.

  The ejection timing from the inkjet head unit 1 is determined using the mark sensor 5 and the alignment mark 23 (step S4).

  When the alignment mark 23 formed on the substrate 2 reaches just below the mark sensor 5, the alignment mark 23 is detected by the mark sensor 5. For details of the detection of the alignment mark 23 by the mark sensor 5, see Embodiment 1.

  Note that the mark sensor 5, the inkjet head unit 1, and the detector 3 are arranged in order in the Y direction. That is, the substrate 2 passes immediately below the mark sensor 5 before the inkjet head unit 1. Until the mark sensor 5 detects the alignment mark 23, the inkjet head unit 1 does not eject droplets.

  Determination of the discharge timing from the inkjet head unit 1 will be described in detail with reference to FIG. FIG. 6 is a schematic view of the ejection failure detection device 10 as viewed from the side, and shows a state in which the mark sensor 5 has detected the alignment mark 23. In addition, the arrow which connects each block represents the transmission direction of a signal, and the board | substrate holding stand 4 and the board | substrate 2 are moving at constant speed in the Y direction.

  The mark sensor 5 detects light reflected from the object by the light emitted by the mark sensor 5. Therefore, when the alignment mark 23 passes directly below the mark sensor 5, the reflectance detected by the mark sensor 5 changes. The change in reflectance is transmitted to the sensor amplifier 62 as a signal. The sensor amplifier 62 amplifies the signal sent from the mark sensor 5 and sends it to the control unit 65.

  Here, the positional information of the substrate 2 and the substrate holder 4 is transmitted from the stage controller 61 to the control unit 65 as an output value of the linear encoder 43 measured using the linear scale 42. The control unit 65 collates the detection of the alignment mark 23 by the mark sensor 5 with the positional information of the substrate 2 and the substrate holder 4 and determines the coordinates of the alignment mark 23 on the substrate 2. Refer to the first embodiment for details on the detection of the alignment mark 23 by the mark sensor 5.

  If the position of the alignment mark 23 (coordinates on the substrate 2) can be determined, the position of the liquid repellent area 21 on the substrate 2 can also be determined (the alignment mark 23 and the mark sensor 5 of the first embodiment). See Thus, the timing at which the liquid repellent area 21 corresponding to each nozzle 12 passes directly below the nozzle 12 can be determined based on the output value of the linear encoder 43.

  Liquid droplets are discharged onto the substrate 2 using the inkjet head unit 1 (step S5).

  The operation of discharging droplets onto the substrate 2 using the inkjet head unit 1 will be described with reference to FIG. FIG. 7 is a schematic view of the ejection failure detection device 10 as viewed from the side, and shows a state in which droplets are ejected toward the substrate 2 of the inkjet head 1. The droplets ejected from the right two nozzles 12 are normally ejected droplets (without causing ejection failure), and the droplets ejected from the leftmost nozzle 12 are flying directions due to ejection failure. In FIG.

  In the process so far, the coordinates of the alignment mark 23 on the substrate 2 are determined. The positional relationship between each of the liquid repellent areas 21 and the alignment mark 23 is measured in advance. Accordingly, each nozzle 12 can discharge droplets toward the corresponding liquid repellent region 21 (normal landing position).

  Here, the normal landing position is a position associated with the mark sensor 5 and each nozzle 12 relative to the X direction and the coordinates of the alignment mark 23 on the substrate 2. That is, the normal landing position is the landing position of the liquid droplet ejected from each nozzle 12 predicted with reference to the coordinates of the alignment mark 23. The normal landing position is a virtual position set on the substrate 2 that does not take into account a deviation in the flight direction caused by dirt around the nozzle 12. Further, the nozzle 12 passes by the substrate 2 moving in the Y direction right above the line segment connecting the centers of the normal landing positions arranged in the Y direction.

  The liquid droplets may be ejected in a state where the liquid repellent area 21 corresponding to each nozzle 12 is directly below the nozzle 12. That is, it is not necessary to perform the movement while moving the substrate 2, and the discharge may be performed while the substrate 2 is stationary. If ejection is performed with the substrate 2 stationary, the time required for the entire process increases somewhat, but it is possible to determine ejection failure with high accuracy.

  In step 4, the control unit 65 stores the output value of the linear encoder 42 corresponding to the discharge timing of each nozzle 12. When the output value of the linear encoder 42 sent via the stage controller 61 matches the output value of the linear encoder 42 stored in the control unit 65, the control unit 65 transmits a droplet discharge signal from the corresponding nozzle 12. Instructs the head controller 63. A droplet is ejected from the nozzle 12 of the inkjet head unit 1 that has received the ejection signal.

  Here, for example, the control unit 65 may be configured to calculate the ejection timing, and the stage controller 61 and the head controller 63 may be directly connected. With this configuration, it is possible to cope with an increase in the speed of movement of the substrate 2 and the substrate holding table 41.

  When the discharge of the liquid droplets onto the liquid repellent area 21 is completed and the liquid repellent area 21 moves to a position where it can be detected by the detector 3, the substrate holder 41 stops moving. The sensor 31 uses the sensor slider 32 to scan in the X direction perpendicular to the scanning direction of the substrate (the depth direction in the drawing of FIG. 5), and the droplets on the liquid repellent area 21 regularly arranged in the X direction. It is in the position where the shape of can be confirmed sequentially.

  When the substrate holding table 41 stops moving, the sensor 31 moves on the substrate 2 in the X direction, so that the sensor 31 detects irregularities on the surface of the substrate 2 (step S6).

  Details of detection of the unevenness of the surface of the substrate 2 by the sensor 31 will be described with reference to FIG. FIG. 8 is a schematic view of the ejection failure detection device 10 as viewed from the side. The sensor 31 scans the substrate 2 to detect the unevenness of the substrate 2 formed by the landed droplets. Show.

  As shown in FIG. 8, on the substrate 2, the liquid droplet 7 that is normally ejected by the nozzle 12 and is stationary in the liquid repellent area 21, and the liquid repellent area 21 and the non-liquid repellent liquid due to the deviation in the flight direction. There is a bad landing droplet 75 resting on the region 22.

  The sensor 31 detects irregularities on the surface of the substrate 2 while moving in the X direction. The droplet 71 stationary on the liquid repellent region 21 is convex in the Z direction. A change in the height of the surface of the substrate 2 due to the droplet 71 is detected using a sensor 31 (displacement sensor). On the other hand, the droplet 75 that is stationary on the liquid-repellent region 21 and the non-liquid-repellent region 22 is not detected by the sensor 31 because it is stationary away from the center of the liquid-repellent region 21.

  Information on the unevenness of the surface of the substrate 2 detected by the sensor 31 is sent to the determination unit 66.

  The determination unit 66 determines the quality of ejection based on the detection result of the sensor 31 (step S7).

  The ejection quality determination in the determination unit 66 will be described with reference to FIG. 9A is a graph of the detection result by the sensor 31a of FIG. 3, FIG. 9B is a graph of the detection result of 31b of FIG. 3, and FIG. 9C is a graph of the detection result of 31c of FIG. It is what. The horizontal axis represents the scanning distance of the sensor 31, and the vertical axis represents the displacement value detected by the sensor 31. The four broken lines indicate the position where the center of the liquid repellent region 21 is located. When the graph intersecting with the broken line indicates a certain value or more, it is determined that the ejection is normal, and when the value is less than the certain value. Is determined as a discharge failure. The constant value used as a criterion for determination may be appropriately selected according to the amount of liquid droplets, the size of the liquid repellent region 21 and the like. It is preferable to determine a suitable numerical value as the constant value by discharging droplets onto the substrate 2 in advance.

  As shown in FIG. 9A, a portion surrounded by a broken line is a waveform of a graph when droplets 72a and 72b (see FIG. 3 or FIG. 4C) are detected. The waveform of this graph indicates that the liquid droplet is stationary in a part of the liquid repellent region 21 and the non-liquid repellent region 22.

  When the droplet 7 landed on a part of the liquid-repellent region 2 and the non-liquid-repellent region 22, most of the landed droplets were dragged to the non-liquid-repellent region 22 due to the surface tension of the liquid droplets. The liquid droplets are separated into a small amount of liquid droplets remaining on the liquid droplets and a liquid droplet spread on the non-liquid-repellent region 22. The amount of the droplet 72a remaining in the liquid repellent region 21 is less than half of the amount of the discharged droplet, and its height is low. Therefore, it is detected as a waveform as described above.

  For this reason, the determination unit 66 determines that the nozzle 12 that has ejected the droplets to the liquid-repellent region 21 surrounded by the broken line is defective in ejection. It is determined that the other three nozzles 12 are discharging well.

  As shown in FIG. 9B, the portion surrounded by the broken line is the waveform of the graph when the droplets 73a and 73b or the droplet 73 (see FIG. 3 or FIG. 4C) is detected. It is. In the droplets 73a and 73b, although the droplet is stationary in a part of the liquid-repellent region 21 and the non-liquid-repellent region 22, the height difference is not detected at all. This is because the ejected liquid droplets are displaced from the Y direction, and are thus separated from the centers of the landed liquid droplets 73a and 73b.

  Of course, the nozzle 12 that has ejected droplets to the liquid-repellent region 21 surrounded by the broken line is determined to be defective by the determination unit 66.

  As shown in FIG. 9C, the portion surrounded by the broken line is the waveform of the graph when the droplet 74 (see FIG. 3 or FIG. 4C) is detected. The waveform of this graph indicates that the droplet 74 is stationary in the non-liquid repellent region 22. It is detected as a waveform having a wide width and a very low height as compared with a droplet ejected well. When a droplet spreads on the non-liquid-repellent region 22 and spreads over a wide area, such a waveform graph is obtained.

  In addition, when a droplet is not ejected due to clogging of the nozzle 12 and the droplet does not fly, it is detected by the sensor 31 in the same manner as the portion surrounded by the broken line in FIG. Therefore, it is possible to detect ejection defects including non-ejection. As described above, the positional deviation with respect to the Y direction can be corrected by adjusting the ejection timing. Therefore, when it is detected as a portion surrounded by a broken line in FIG. 9B, the liquid repellent area where the height difference could not be detected at all using the sensor 32 (see FIGS. 3 and 4). Imaging of the vicinity of 21 is performed.

  As described above, a droplet that has caused a deviation in the landing position is detected as a shape having a clearly different height compared to a droplet that has been ejected satisfactorily. Further, the detection result includes a certain amount of position information. Therefore, the determination unit 66 can easily detect the nozzle 12 that has caused the ejection failure.

  Based on the determination result of the determination unit 66, the controller 65 determines the nozzle that has caused the ejection failure (step S8).

  As shown in FIG. 9, the four broken lines are the centers of the liquid repellent region 21 that is assumed from the movement distance of the sensor 31. The liquid repellent area 21 determined to be defective in discharge is determined, and the nozzle 12 that has ejected droplets toward the center of the liquid repellent area 21 is determined based on the correspondence between the nozzle 12 and the liquid repellent area 21 obtained in step S5. decide.

  Either the nozzle 12 determined to be defective in discharge is not used, or after performing a conventionally known recovery process such as cap suction, another measure is taken to check for defective discharge again.

  Here, as shown in FIG. 2, when a perfect liquid repellent region 21 is formed on the substrate 2, even if a positional deviation occurs in all directions of 360 °, ejection failure occurred. The nozzle 12 can be accurately detected.

  On the other hand, when the liquid repellent region 21 is formed in a rectangular shape extending in the Y direction as shown in FIG. 3, it is possible to accurately determine a discharge failure with respect to the positional deviation with respect to the X direction. Here, when a detection result as shown in FIG. 9B is obtained, the detection is performed using the image sensor 32 in order to confirm whether a positional deviation has occurred in the Y direction or a non-ejection has occurred. The result is obtained and the vicinity of the other region is imaged. By analyzing the captured image, it becomes clear whether ejection is not occurring or the position is shifted in the Y direction. If the position is shifted, the midpoint 25 of the liquid repellent region 21 (see FIG. 3). The degree of adjustment of the discharge timing of the nozzle 12 can be determined by measuring the distance from the nozzle 12.

  The above-described configuration shown in FIG. 3 is a production apparatus using an ink jet system provided with the ejection failure detection device 10 where the scanning direction of the substrate 2 and the scanning direction of the manufacturing substrate are the same (for example, the substrate This is effective when 2 includes a manufacturing substrate. This is because, as described above, the positional deviation in the Y direction (scanning direction of the manufacturing substrate) can be solved by correcting the discharge timing in discharging the droplets onto the manufacturing substrate. It is. On the other hand, there is no means for correcting the positional deviation in the X direction, so it is necessary to determine that the discharge is defective.

  As described above, droplets are landed on all the nozzles 12 included in the inkjet head unit 1 toward the liquid repellent area 21 formed corresponding to each nozzle 12. The state (the shape and the distance from the liquid repellent region 21) of the landing droplet that is stationary in the liquid repellent region 21 can be detected. It becomes possible to detect ejection failure (positional deviation and non-ejection) for all nozzle holes. Based on the detection result, it can be determined whether or not the process for the inkjet head unit 1 is necessary.

  With the above processing, it is possible to accurately and rapidly detect the nozzle 12 that has caused a droplet ejection failure using a simple and inexpensive method.

  The ejection failure detection apparatus of the present invention was applied to a manufacturing apparatus using an ink jet system. The above manufacturing apparatus is an apparatus for manufacturing a color filter substrate for a liquid crystal display device. As the substrate 2 according to the present invention, a manufacturing substrate further provided with a region for manufacturing a color filter substrate is used. It was.

  FIG. 10A is a plan view of the glass substrate 20 for manufacturing, which is composed of a substrate 2 for detecting defective ejection and a color filter substrate 26. A polyimide pattern having a height of 1 μm is formed on the glass substrate 20. The pattern is formed by using a conventionally known technique such as selective exposure corresponding to the pattern after uniformly applying a photocurable liquid polyimide material by spin coating. The position of the pattern can be manufactured with an accuracy of about 2 μm and the pattern width can be manufactured with an accuracy of about 0.5 μm.

  FIG. 10B is an enlarged plan view of a portion surrounded by a broken line in FIG. 10A, and FIG. 10C is a cross-sectional view of a line segment L-L ′. The liquid repellent region 21 and the bank pattern 25 are produced by the above pattern formation using a polyimide material, and the contact angle with respect to pure water can be set to about 100 ° by the microwave plasma treatment. On the other hand, the bottom surface of the pixel portion 26 surrounded by the non-liquid-repellent region 23 and the bank pattern 25 is made of glass, and the contact angle with respect to pure water is set to about 15 ° by microwave plasma treatment. Can do. The contact angle between the liquid repellent region 21 and the bank pattern 25 can be adjusted by setting conditions for microwave plasma processing.

  The liquid repellent region 21 is formed as a shape protruding from the non-liquid repellent region 22. The discharge for detecting the discharge failure is landed toward the position indicated by the arrow a. On the other hand, the ejection to the pixel is made to land toward the position of the arrow a.

  As a droplet material used for ejection, a material having a smaller surface tension and higher viscosity than pure water was used. The contact angle of the droplet material with respect to the surface of the liquid repellent region 21 and the bank pattern 25 can be adjusted in a range of 50 ° to 100 °, and the contact of the droplet material with the surface of the non-liquid repellent region 23 and the pixel portion 26. The angle was adjustable in the range of 5-30 °.

  The ejection operation for detecting ejection failure and the ejection operation to the pixels 26 were performed while scanning the glass substrate 20 in the Y direction using the inkjet head 11 in which a plurality of nozzles 12 are arranged in the X direction.

  The circular liquid repellent region 21 is a region having a diameter of 40 μm. The distance in the X direction between two adjacent nozzles 12 (projection pitch projected in the X direction) is 30 μm, which is equal to the distance W4 between the centers of the liquid repellent areas 21a and 21b. The distance W5 between the centers of the liquid repellent areas 21a and 21c is 60 μm, which is twice the distance in the X direction (projection pitch projected in the X direction) between two nozzles 12 adjacent to the nozzle 12. Therefore, by adjusting the discharge timing, the three nozzles 12 arranged in succession can discharge droplets toward the liquid-repellent regions 21a, 21b, and 21c. The glass substrate 20 has a length of 2 m in the X direction and 3 m in the Y direction. In the inkjet head 11, a plurality of nozzles 12 are provided in an array having a pitch of 30 μm so as to cover the entire region in the X direction.

  By disposing the liquid repellent areas 21 in a staggered manner, the non-liquid repellent areas 22 are formed so as to surround the liquid repellent areas 21 even when W4 is smaller than the size of the liquid repellent areas 21. be able to.

  A droplet of 1 pl, 2 pl, 4 pl, or 6 pl was landed by using the inkjet head 11 on a surface having a contact angle representing wettability of 5 to 80 °. The numerical values shown in Table 1 are a summary of the diameters of the landed droplets as viewed from above and the results of measuring the height of the droplets. The droplet material actually used for manufacturing the color filter substrate was used as the droplet material. The diameter of the droplet was measured using a non-contact type three-dimensional measuring machine (QUICKVISON manufactured by Mitutoyo Corporation). The maximum height of the droplet was measured using a laser displacement sensor (LK-G10 manufactured by Keyence). A surface having a contact angle of 5 to 30 ° was formed by performing an ashing process under different conditions on the glass substrate 20. The surface having a contact angle of 60 to 80 ° was formed by performing microwave plasma treatment on the polyimide surface.

  The droplet diameter had a reproducibility with an error of about plus or minus 2 μm, and the maximum height of the droplet had a reproducibility with an error of about plus or minus 0.5 μm.

  From Table 1, the non-liquid repellent region 22 (contact angle 5 to 30 ° in Table 1) and the liquid repellent region 21 (contact angle 60 to 80 ° in Table 1) are at least twice as large as the maximum height. Have a difference. It was found that by measuring the maximum height of the landed droplets, it is possible to grasp the amount of droplets stationary on the liquid repellent region 22.

  In this embodiment, the droplet amount is set to 6 pl, the contact angle of the droplet material with respect to the surface of the liquid repellent region 21 is 60 °, and the contact angle of the droplet material with respect to the surface of the non-liquid repellent region 22 is 5 °. The glass substrate 20 processed in the above was used. At this time, the diameter of the liquid repellent region 21 was set to 40 μm because the diameter when the 6 pl droplet was still on the liquid repellent region 21 was about 36 μm.

  FIG. 11 is a schematic diagram when the discharged liquid droplet 7 has landed on the liquid repellent area 21, and FIG. 11A shows the time when the liquid droplet has landed at the center of the liquid repellent area 21 (during normal landing). Show. FIG. 11 (b) shows a case where landing is made with a deviation of 5 μm from the center of the liquid repellent region 21. FIG. 11 (c) shows a case where the impact is made with a deviation of 10 μm from the center of the liquid repellent region 21. FIG. 11 (d) shows a case where landing is made with a deviation of 15 μm from the center of the liquid repellent region 21.

  As shown in FIG. 11A, when the liquid droplets land on the center of the liquid repellent area 21, the non-liquid repellent area 22 and the liquid droplet 71 do not contact each other.

  As shown in FIG. 11 (b), when landing at a deviation of 5 μm from the center of the liquid repellent area 21, a part of the liquid droplet reaches the non-liquid repellent area 23, and one of the liquid droplets landed on the liquid repellent area 21. Part is drawn into the non-liquid-repellent region 22. Thus, two droplets are formed, the landing droplet 75a on the liquid repellent region 21 and the landing droplet 75b on the non-liquid repellent region 22. At this time, the landing droplet 75a that is stationary on the liquid repellent region 21 has a convex shape in which the amount of the discharged droplet is divided and has a vertex at a position shifted from the center position. Therefore, when the displacement sensor is used, the height at the position of the broken line in the figure is measured, so that it is detected as a convex shape that is much lower than the droplet 71 in FIG.

  FIGS. 9C and 9D show a state in the case of 10 μm or 15 μm from the center of the liquid-repellent region 21, and the amount of droplets that remain on the liquid-repellent region 21 decreases as the positional deviation increases. Become. Furthermore, the position of the apex of the landing droplet from the center of the liquid repellent region 21 becomes far. Therefore, the height detected by the displacement sensor becomes smaller. It is also possible to measure the amount of misalignment using this height value detected by the displacement sensor.

  In the present embodiment, the case where the liquid droplet in which the positional deviation has occurred is divided into the liquid-repellent region 21 and the non-liquid-repellent region 22 has been described. Even if the position is shifted, all of the landing droplets that contact a part of the non-liquid-repellent region 22 may be drawn to the non-liquid-repellent region 22 side.

  In this embodiment, the liquid repellent region 21 is about 1 μm higher than the substrate surface, but the liquid repellent region 21 does not have to be convex. The liquid repellent region 21 may be selectively formed on the surfaces having the same height. If the liquid-repellent region 21 is formed in a convex shape, if a displacement occurs, the landing droplet easily moves from the liquid-repellent region 21 to the non-liquid-repellent region 22, so that it is easy to determine ejection failure due to the displacement. It becomes.

  The size of the liquid-repellent region varies depending on the amount of liquid droplets, the contact angle of the liquid-repellent region, and the allowable positional deviation, but the diameter is 3 to 10 μm larger if it is circular with respect to the diameter of the landing droplet that is the occupied region, If it is a rectangle, it is desirable that the width is 3 to 10 μm larger.

  When the contact angle of the liquid droplet with respect to the surfaces of the liquid repellent area 21 and the non-liquid repellent area 22 is used as a parameter, (1) when landing at the center (normal landing position) of the liquid repellent area 21, (2) the liquid repellent area 21 The repeated stability of the liquid droplets was confirmed in the case of landing at a position deviating from the center (position where the position shift occurred). The results are shown in Table 2.

  In (1), it was made to land on the center of 100 liquid-repellent area | regions 21 using one nozzle confirmed not to raise | generate position shift. When the contact angle of the surface of the liquid repellent region 21 with respect to the droplet material was 50 to 80 °, all of the droplets were stationary at a normal position. On the other hand, when the contact angle is 90 °, the liquid droplet is in contact with one region other than the liquid repellent region 21 despite the fact that the droplet landed near the center of the liquid repellent region 21 at one point when the contact angle is 100 °. This is presumably because the landing droplets were displaced from the liquid repellent region 21 after landing because the liquid repellency was too high. In addition, the deviation tends to increase as the flying speed of the droplet increases.

  In (2), droplets were landed at a position shifted by 5 μm from the center (normal position) of the liquid-repellent region 21 using one nozzle that was confirmed not to cause positional displacement. This was performed on 100 liquid-repellent regions 21. Then, the height variation detected by the displacement sensor was measured by aligning the sensor center of the displacement sensor with the center of the liquid repellent region 21. The case where the standard deviation was within 0.5 μm as the variation value was evaluated as “◯”, the case where it was within 2 μm, and the case where it was 2 μm or more as x. In addition, in the case where 10 or more results that are judged to be normal ejection were obtained although the ejection failure should have been originally intended, it was marked as x. When the contact angle of the liquid repellent region 21 is 90 ° or more, as described above, since the droplets are likely to shift after landing, the variation is large and the standard deviation is large. When the contact angle of the liquid-repellent region 21 is 50 to 60 ° and the contact angle of the non-liquid-repellent region is 30 °, the difference in contact angle between the liquid-repellent region 21 and the non-liquid-repellent region 22 is small, so This is probably because the droplets are not sufficiently drawn into the non-liquid-repellent region 22. From the above results, the contact angle of the liquid repellent region 21 is preferably 50 to 90 °, and more preferably 60 to 80 °. Furthermore, the difference in contact angle between the liquid repellent region 21 and the non-liquid repellent region 22 is preferably 40 ° or more.

  It is preferable that water absorption is provided near the boundary between the non-liquid-repellent region 22 and the liquid-repellent region 21. Giving water absorption means, for example, that the vicinity of the boundary is formed of a porous material. With respect to the non-liquid-repellent region 22 that forms the periphery of the liquid-repellent region 21, examples of the porous material include a sponge-like material made of a vinyl alcohol resin. When a sponge-like material made of vinyl alcohol resin is disposed near the boundary between the non-liquid repellent region 22 and the liquid repellent region 21, a part of the liquid droplet that has caused the positional displacement comes into contact with the non-liquid repellent region 22. Most of them are absorbed by the non-liquid-repellent region 22. Therefore, it is possible to more accurately detect the nozzle 12 that has caused the ejection failure (positional deviation).

  A configuration example of the detector 3 will be described below with reference to FIG. FIG. 2B is a view of the device side surface of FIG. 1 viewed from the Y direction. The detector 3 is connected to the sensor slide rail 33 so as to be movable in the X direction, and the sensor slide rail 33 is fixedly attached to the slide beam 34. The detector 3 can move at a constant speed and stop at an arbitrary position in the X direction under the control of a stepping motor having a ball screw feed mechanism.

  The detector 3 is provided with a sensor 31 and an image sensor 32 (for example, ADP-210 manufactured by Flowbell), and the detector 3 moves along the sled rail 33 at a constant speed while the shape of the surface of the substrate 2 is set. The state (the presence or absence of landing droplets on the liquid repellent region 21) is detected. As the sensor 31, a laser displacement type sensor (for example, LK-G10 manufactured by Keyence) or a reflectance measurement type sensor (for example, F-2HA manufactured by Keyence) was used. When a laser displacement type sensor is used as the sensor 31, the maximum height of the landing droplet at the normal landing position (inside the liquid repellent region 21) is measured, and whether or not ejection failure has occurred from the obtained height value. Was judged. When a reflectance measurement type sensor is used as the sensor 31, ejection is performed from the amount of change in reflectance at the normal landing position by utilizing the fact that the reflectance decreases when light is applied to the surface of a curved droplet. The presence or absence of defects was determined. Any sensor 31 may be used, but the measurement accuracy can be further improved by using a sensor for measuring the height of the landing droplet.

  The liquid repellent region 21 provided on the substrate 2 has a rectangular shape whose short side is the direction orthogonal to the scanning direction of the substrate 2 as shown in FIG. The length of the short side of the liquid-repellent region 21 having a rectangular shape was set to be 3 to 10 μm longer than the diameter of the landing droplet.

  The sensor 31 detected all of the landing droplets. As a result of measuring the height at the normal landing position, when the change in height is large (for example, about half of the normal value), it was determined that a positional shift occurred in the X direction. Droplets having a large change in height correspond to the landing droplets 72a and 72b in FIG. The deviation in the X direction cannot be corrected by adjusting the ejection timing of the droplets from the nozzle. Therefore, all the deviations in the X direction were determined to be ejection failures. The nozzle hole that ejected the droplet that caused the deviation in the X direction was determined to be a defective ejection and moved to the next step such as a repair operation.

  Next, those whose height was not normal but whose variation was small were selected. This is highly likely to be displaced in the Y direction. Since the deviation in the Y direction can be corrected by adjusting the ejection timing at the time of droplet ejection, the imaging using the imaging sensor 32 and the measurement of the distance causing the deviation were performed. The operation of imaging the landing droplet from the upper surface in the normal direction of the substrate 2 using the imaging sensor 32 and determining the landing position from the image takes time compared to the inspection of the sensor 31 (10 per second). Or less). However, as a result of assuming that the liquid droplets that are misaligned in the X direction are defective in ejection, the ratio of the nozzles 12 that require imaging is small with respect to all the nozzles 12.

  By using the sensor 31 that can be detected at a high speed, it is possible to detect a nozzle that has caused a positional shift in the X direction that cannot be adjusted. Therefore, it is possible to reduce the number of nozzles 12 that need to acquire landing position deviation data in the Y direction using the imaging sensor 32. In other words, it is possible to efficiently detect the non-adjustable ejection defective nozzle 12 including the positional deviation without reducing the detection processing speed, and to detect and adjust the adjustable ejection defective nozzle. A correction value can be obtained.

  FIG. 12 is an example of an image obtained by imaging the landing droplet by the imaging sensor 32, and FIG. 12A is an image obtained by imaging the landing droplet 43 that may be displaced in the Y direction by the sensor 31. A binarization process is performed on an image obtained by imaging a landing droplet, the position of the center of gravity of the image of the landing droplet is calculated, and a deviation amount W6 in the Y direction is derived based on the pixel resolution and the number of pixels of the CCD camera. Is possible. In the Y direction which is the scanning direction of the substrate 2 (scanning direction when discharging is performed on the production substrate), the discharge timing of the droplets of the nozzle 12 that has caused the positional shift is controlled based on the derived shift amount W6. By doing so, it is possible to correct to a normal landing position. On the other hand, FIG. 12B shows an image of a landing droplet that the sensor 31 has determined to be normal ejection. Although FIG. 12B is shown here as a comparative control, since it is only a wasteful process, it does not pick up an image of a droplet that has been ejected normally in the actual detection of ejection failure.

[Other configurations]
The present invention can also be realized by the following configuration.

(First configuration)
An inkjet head having nozzle holes for discharging droplets;
A first region having liquid repellency provided at a normal landing position of a droplet discharged from the nozzle hole and configured by a region corresponding to a region occupied by the landing droplet;
A discharge detection substrate comprising a second region provided around the first region and having a liquid repellency different from that of the first region;
Detection means for detecting a discharge failure based on the shape of a landing droplet at a normal landing position;
An ejection failure detection apparatus comprising:

(Second configuration)
The ejection failure detection device according to the first configuration, wherein the second area is lyophilic with respect to the first area.

(Third configuration)
The ejection failure detection device according to the first or second configuration, wherein a contact angle of the droplet material is 50 to 90 ° in the first region.

(Fourth configuration)
The ejection failure detection device according to any one of first to third, wherein the first region is substantially circular.

(Fifth configuration)
The first region is formed by arranging a plurality of substantially circular shapes in one direction,
The detection means can scan in the one direction;
The ejection failure detection device according to any one of the first to third configurations.

(Sixth configuration)
Any one of the first to third configurations, wherein the first region is continuous in a strip shape in one direction, and a plurality of the first regions are arranged in a second direction different from the one direction with the second region interposed therebetween. Discharge failure detection device according to the above.

(Seventh configuration)
The detection means includes a first sensor capable of scanning in the second direction;
The landing droplet selected based on the output of the first sensor comprises a second sensor capable of detecting the amount of positional deviation of the droplet with respect to the one direction.
The ejection failure detection device according to the sixth configuration.

(Eighth configuration)
The ejection failure detection apparatus according to any one of the first to seventh configurations, wherein the detection unit includes a sensor capable of detecting a height in a normal direction of the substrate.

(Ninth configuration)
The ejection failure detection device according to any of the first to eighth configurations, wherein the first region is convex with respect to the second region.

(Tenth configuration)
The ejection failure detection device according to any one of the first to ninth configurations, wherein the second region is made of a porous material at least around the first region.

(Eleventh configuration)
The ejection failure detection device according to any one of the first to tenth configurations, wherein the ejection detection substrate is provided in a substrate processed using the inkjet head.

  By using the present invention, it is possible to accurately and rapidly detect a nozzle that has caused a droplet ejection failure using a simple and inexpensive method. Therefore, it can be used for detection of ejection defects in general manufacturing apparatuses using the inkjet method. In particular, it is suitable for application to a manufacturing apparatus such as a color filter substrate or an organic EL (electroluminescence) element used in an image display apparatus.

It is the apparatus block diagram which looked at the discharge defect detection apparatus of this invention from the side. (A) is a top view which shows a part of ejection failure detection apparatus of FIG. 1, FIG.2 (b) is a side view which shows a part of ejection failure detection apparatus. It is the top view which showed the board | substrate and detector which landed the droplet which concerns on this invention. (A) shows a modification of the substrate of FIG. 2 (a), and (b) is a plan view showing the substrate and detector of FIG. 4 (a) on which droplets have landed. It is a flowchart explaining the process of the discharge defect detection apparatus which concerns on this invention. It is a side view explaining the process which positions a board | substrate among the processes of the discharge defect detection apparatus which concerns on this invention. It is a side view explaining the process which discharges a droplet to a board | substrate among the processes of the discharge defect detection apparatus which concerns on this invention. It is a side view explaining the process which detects the shape of the droplet made to land on the board | substrate among the processes of the discharge defect detection apparatus which concerns on this invention. (A) is a graph which shows the result of having detected the surface shape in line segment EE 'of the board | substrate of FIG. 3 with the detector, (b) is the surface in line segment FF' of the board | substrate of FIG. It is a graph which shows the result of having detected the shape with the detector, (c) is a graph which shows the result of having detected the surface shape in line segment GG 'of the board | substrate of FIG. 3 with the detector. (A) is the top view which looked at the color filter board | substrate of Example 1 from the upper surface, (b) is the top view to which the broken-line part of (a) was expanded, (c) is (b) It is sectional drawing in line segment LL '. (A) is sectional drawing which shows the shape of a droplet when a droplet lands on the center of a liquid repellent area, (b) is a time when a droplet lands on a position 5 μm away from the center of the liquid repellent area. FIG. 3C is a cross-sectional view showing the shape of a liquid droplet, FIG. 3C is a cross-sectional view showing the shape of the liquid droplet when the liquid droplet has landed at a position 10 μm away from the center of the liquid-repellent region, and FIG. It is sectional drawing which shows the shape of a droplet when a droplet reaches the position 15 micrometers away from the center of the area | region. (A) is a top view which shows the droplet which produced position shift in the Y direction, and the distance which produced the shift, (b) is a top view which shows the droplet which did not raise | generate position shift.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head unit 2 Board | substrate 3 Detector (detection means)
7 Liquid droplet 10 Discharge failure detection device 11 Inkjet head 12 Nozzle 21 Liquid repellent area (first area)
22 Non-liquid repellent area (second area)
26 Color filter substrate (area for pattern formation)
31 sensor (first sensor)
32 Imaging camera (second sensor)
66 Determination part (determination means)

Claims (16)

A discharge failure detection device that includes an inkjet head that discharges droplets to a substrate through a nozzle and detects a droplet discharge failure in the nozzle,
On the surface of the substrate,
A first region having a shape corresponding to an area occupied by a droplet landed on the substrate and having a first wettability with respect to the droplet;
A second region having a second wettability higher than the first wettability and being in contact with the first region;
The inkjet head discharges droplets targeting the first region,
Discharge failure detection device
Detection means for detecting at least one of the shape and position of the droplet in contact with the first region;
An ejection failure detection apparatus comprising: a determination unit that determines whether or not a droplet is discharged based on a detection result of the detection unit.   2. The ejection failure detection device according to claim 1, wherein a contact angle between the droplet and the first region in a state where the droplet is stationary on the first region is 50 ° to 90 °. .   The contact angle between the droplet and the first region when the droplet is stationary on the first region, and the droplet and the second region when the droplet is stationary on the second region The ejection failure detection device according to claim 2, wherein the difference between the contact angle and the contact angle is 40 ° or more.   The ejection failure detection device according to claim 1, wherein the first region is substantially circular.   5. The ejection failure detection device according to claim 4, wherein the plurality of first regions are formed at equal intervals on a straight line perpendicular to the moving direction of the substrate as viewed from the inkjet head. .   The ejection failure detection device according to claim 4 or 5, wherein the first region is surrounded by the second region.   4. The ejection failure detection device according to claim 1, wherein the first region has a strip shape, and a long side direction of the first region is parallel to a scanning direction of the substrate.   8. The ejection failure detection device according to claim 7, wherein each of the plurality of first regions is arranged at equal intervals and in parallel.   The ejection failure detection device according to claim 7 or 8, wherein two long sides of the first region are in contact with the second region. The normal direction of the substrate surface on which the first region and the second region are formed substantially coincides with the direction opposite to the direction of gravity,
The ejection failure detection device according to claim 1, wherein the first region protrudes from the second region.   The ejection failure detection device according to any one of claims 1 to 10, wherein water absorption is provided near a boundary between the second region and the first region. The detection means includes a first sensor,
The ejection failure detection device according to claim 1, wherein the first sensor detects unevenness of the first region on the surface of the substrate.   The ejection failure according to any one of claims 1 to 12, wherein the first sensor detects irregularities on the surface of the substrate while scanning so as to pass right above the center of the first region. Detection device. The detection means further includes a second sensor,
The second sensor determines a region on the substrate to be detected based on the unevenness of the substrate surface detected by the first sensor, and determines the shape of the droplet, the moving distance from the center of the first region, and the first The ejection failure detection device according to claim 13, wherein a movement direction from the center of one region is detected.   The discharge defect detection device according to claim 1, wherein a region for forming a desired pattern is further formed on the substrate by landing the droplets. . An ejection failure detection method comprising an inkjet head for ejecting droplets onto a substrate through a nozzle, and detecting a droplet ejection failure at the nozzle,
A shape matching the nozzle, a first region having a first wettability with respect to the droplet, and a second region having a second wettability higher than the first wettability in contact with the first region A step of ejecting liquid droplets targeting the first region with respect to the substrate on which is formed;
Detecting at least one of the shape and position of the droplet in contact with the first region;
And a step of determining whether the discharge is good or not based on a detection result.

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