JP2005205317A - Ink jet applicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means which prevents the generation of satellite, and improves the application of a coating material to a substrate. <P>SOLUTION: The control of PC20 allows a drop of the coating material to discharge from an outlet of an ink jet head 5, and in accordance with this, causes an instant photogenesis of a light source 31 to image the drop with a camera 30 under the lighting. This photogenesis timing is delayed sequentially and repeated, and an applied voltage for the outlet every this repetition changes sequentially, by which the discharged drop is imaged at the sequential position in the eyesight of the camera 30, and the generation of the satellite is imaged. The imaging results can produce the optimum applied voltage for the outlet in order that the stable drop reach to the applied substrate, and the height of the ink jet head for the applied surface of the applied substrate, which is required in order that the drop hit the predetermined region of the applied substrate exactly. According to the determined parameter, the application to the applied substrate is carried out by using the ink jet head 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coating apparatus using an inkjet head, and more particularly to an apparatus for reading the ejection characteristics of an inkjet head.

  In recent years, a technique for obtaining a functional element by forming a predetermined pattern by coating thin films having different characteristics on the same substrate has been developed. As an effective method, different thin film patterns are formed on the same substrate by an ink jet method.

  However, in the case of using the ink jet method, there arises a problem in terms of process such that different thin film materials are mixed on the substrate. Specifically, a technique of coating a polymer light emitting material in a display device such as an organic EL (Eictro-Luminescence) device using an inkjet method, or a thin film material such as a colored resin in a color filter is used. In the case where a thin film pattern is formed by filling a liquid material using an ink jet method, there is a problem that the discharged liquid material flows out to adjacent pixels.

  In the ink jet method, ink droplets (main droplets) for forming a pattern are ejected from an ink jet head by expanding and contracting an ink chamber using an expansion element such as a piezo element. After this, a plurality of small droplets called satellites, which are smaller than the main droplet and slower in speed, are generated. The cause of the satellite is that the liquid (ink) moves into the inkjet head due to the shrinkage of the meniscus in the inkjet head caused by the shrinkage of the bubbles in the inkjet head after the ejection of the main droplet and the deformation of the piezo element, As a reaction after the movement, it is known that the liquid starts to move out of the ink jet head, and this causes the liquid to be ejected again. The satellite is delayed in time with respect to the main droplet, and since it is a minute droplet, it is highly likely that the satellite will scatter and land outside the partition area determined for pattern formation. This may cause the display function of the device to deteriorate.

  In order to solve such problems, many techniques for preventing the generation of satellite droplets have been proposed.

  As an example, a method of suppressing residual vibration by applying a second pressure fluctuation following the first pressure fluctuation for generating a main droplet has been proposed (see, for example, Patent Document 1).

As another example, after deformation of an electromechanical transducer (for example, a piezoelectric element), satellite droplets generated by the protrusion of liquid out of the discharge port due to large residual vibration of the meniscus accompanied by rebound displacement are equivalent to the main droplet. Thus, there has been proposed a method of ejecting (jetting) and coalescing so as to partially overlap a main droplet on a medium on which a pattern is formed (for example, see Patent Document 2).
JP 59-1333067 A JP 7-285222 A

  By the way, in the technologies described in Patent Documents 1 and 2, it is extremely difficult to control the landing accuracy of the satellite itself, and the idea of treating the main droplet and the satellite equally is based on the specifications of the main droplet itself and, consequently, the inkjet head. The problem that the landing accuracy cannot be secured remains.

  Ink jet heads may generate satellites even within the recommended use range (for example, a specified applied voltage) due to their lifespan and individual differences. This problem is also described in Patent Documents 1 and 2 above. The described technique cannot be solved. Further, it is difficult to determine the lifespan and the solid difference of the ink jet head unless the ink jet head is regularly monitored.

  The object of the present invention is to solve such a problem, reliably prevent the generation of satellite droplets, ensure that the droplets of the coating material land on a predetermined area, and facilitate the ejection characteristics of the inkjet head. An object of the present invention is to provide an ink jet coating apparatus which can be known.

  In order to achieve the above-mentioned object, the present invention includes an application mechanism portion that discharges a coating material from a discharge port of an inkjet head and applies it to a substrate, and an inspection mechanism portion that inspects an inkjet head used in the application mechanism portion. The inspection mechanism unit detects a state of a droplet of the coating material ejected from the ejection port of the inkjet head, and determines an optimum applied voltage to the ejection port of the inkjet head based on the detection result of the detection unit And a voltage determining means.

  The present invention also relates to an ink jet coating apparatus that ejects a coating material from a discharge port of an ink jet head to apply to a substrate or the like, and detects detection of a state of a droplet of the coating material discharged from the discharge port of the ink jet head And a voltage determining means for determining the optimum applied voltage to the ejection port of the ink jet head based on the detection result of the detecting means, enabling inspection of the ink jet head used for applying a coating material to a substrate or the like It is what made the structure.

  In the present invention, the detecting means detects whether or not a droplet is discharged, the amount of the droplet and the flight direction of the droplet.

  Furthermore, the present invention includes a determination unit that determines the performance state of the inkjet head from the detection result of whether or not droplets are discharged, and a unit that issues a warning for replacing the inkjet head according to the determination result of the determination unit. Is.

  Further, according to the present invention, the voltage determining means obtains a minimum applied voltage that can be ejected as droplets and a maximum applied voltage that does not generate satellites based on the detection result of the detecting means, and the minimum applied voltage and the The optimum applied voltage is determined between the maximum applied voltage.

  Further, according to the present invention, the voltage determining unit determines an oscillation voltage that is a maximum applied voltage at which droplets cannot be ejected, based on a detection result of the detecting unit.

  According to the present invention, it is possible to discharge droplets of the coating material with an optimal droplet amount without generating satellites, and it is possible to reliably land the discharged droplets on a predetermined region of the coating substrate, Further, the ejection characteristics of the ink jet head can be easily known, the ink jet head can always be used in a good state, and a good application state of the application material can always be obtained on the application substrate.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, although the following embodiment makes an example application to the manufacturing apparatus of an organic EL device, this invention is not limited to this.

  FIG. 1 is a perspective view showing a first embodiment of an ink jet coating apparatus according to the present invention. A is a coating mechanism portion for coating a coating material in this embodiment, 1 is a pedestal, 2 is a frame, and 2a is a frame. Horizontal beam of frame 2, 2b is right leg of frame 2, 2c is left leg of frame 2, 3 is Z-axis stage, 4 is Z-axis drive motor, 5 is inkjet head, 6 is head bracket, 7 is head drive Substrate, 8 is a coating substrate, 9 is an X-axis stage, 10 is an X-axis drive motor, 11 is a Y-axis stage, 12 is a Y-axis drive motor, 13 is a θ-direction rotating unit, 14 is a suction table, 15 is a cleaning device, Reference numeral 16 denotes a coating material bottle, 17 denotes a bottle holder, 18 denotes a cleaning liquid bottle, 19 denotes a monitor, and 20 denotes a PC (personal computer).

  In the same figure, this 1st Embodiment equips the application | coating mechanism part A with PC20 and the monitor 19, and also provided the test | inspection mechanism part shown in FIG.

  In the coating mechanism part A, a gate-shaped frame 2 is fixedly mounted on the gantry 1 so as to be parallel to the X-axis direction. A Z-axis stage 3 is fixedly attached to the center of the front surface of the horizontal beam 2 a of the frame 2 so that the surface thereof is perpendicular to the upper surface of the gantry 1. A head bracket 6 and a Z-axis drive motor 4 are provided on the Z-axis stage 3, and the head bracket 6 can be moved in the Z-axis direction (vertical direction) by the Z-axis drive motor 4. An ink jet head 5 is detachably attached to the head bracket 6.

  A bottle holder 17 is attached to the right leg portion, that is, the right leg portion 2b as viewed from the front side of the frame 2 so as to be movable in the Z-axis direction, and the coating material bottle 16 is attached to the bottle holder 17. It is installed. Further, in the vicinity of the coating material bottle 16, a cleaning liquid bottle 18 in which a cleaning solvent for cleaning the flow path of the coating material in the inkjet head 5 is provided. The coating material bottle 16 and the cleaning liquid bottle 18 can supply the coating material to the inkjet head 5 and supply the cleaning liquid to the cleaning device 15 by a supply unit (not shown). Further, the coating material bottle 16 and the cleaning liquid bottle 18 can be appropriately replaced. Further, a head drive substrate 7 is attached to the left leg 2 c of the frame 2.

  A Y-axis stage 11 is attached to the upper surface of the gantry 1 so as to extend between the right leg 2b and the left leg 2c of the frame 2, and a Y-axis drive motor 12 and the Y-axis stage 11 are attached to the Y-axis stage 11. An X-axis stage 9 is provided so as to be movable in the Y-axis direction with respect to the Y-axis stage 11. The X-axis stage 9 is provided with an X-axis drive motor 10 and a θ-direction rotating unit 13 that can move in the X-axis direction with respect to the X-axis stage 9. The θ-direction rotating unit 13 rotates in the θ direction by driving a drive motor (not shown). The suction table 14 is fixed to the upper surface of the θ-direction rotating unit 13 so that the upper surface thereof is parallel to the upper surface of the gantry 1. Accordingly, the suction table 14 moves in the Y-axis and X-axis directions by driving the Y-axis drive motor 9 and the X-axis drive motor 12, and in the θ direction by driving the drive motor of the θ-direction rotating unit 13. Rotate.

  The upper surface of the suction table 14 forms a mounting surface for the coating substrate 8 on which the coating material is applied by the inkjet head 5, and a plurality of fine suction holes communicating with a vacuum generator (not shown) are provided on the mounting surface. Yes. The coating substrate 8 placed on the suction table 14 is sucked and held on the suction table 14 by the negative pressure supplied from the negative pressure supply means of the vacuum generator to the suction holes. Thus, the surface of the coating substrate 8 sucked and held on the suction stage 14 and the bottom surface of the inkjet head 5 face each other in parallel. A cleaning device 15 for preventing clogging of the ink-jet head 5 and eliminating clogging factors is attached to the front end surface (front side in the drawing) of the suction table 14.

  The lowering stroke of the ink jet head 5 driven by the Z-axis drive motor 4 is set so that at least the ink jet head 5 is further lowered than the position of the cleaning device 15.

  In the first embodiment, a PC 20 and a monitor 19 are provided in addition to the coating mechanism A having the above-described configuration. In the PC 20, droplet discharge control of the inkjet head 5, drive control of components for the entire inkjet coating apparatus, state monitoring, and the like are performed.

  FIG. 2 is a plan view schematically showing a specific example of the bottom surface (discharge surface) of the inkjet head 5 in FIG. 1, where 5a is a coating material discharge surface, 21 is an orifice plate, 22 is a coating material discharge port, 23 Is a discharge port line, and 24 is a reference plane.

  In the drawing, a plurality of coating material storage chambers (not shown) are provided in the inkjet head 5, and each has a coating material discharge chamber 22. An orifice plate 21 is affixed to the coating material discharge surface 5a of the inkjet head 5, and a linear discharge passing through the center of the orifice plate 21 in the width direction (vertical direction in the drawing: Y-axis direction in FIG. 1). A coating material discharge port 22 of the coating material storage chamber is arranged along the outlet line 23. In the coating mechanism section A shown in FIG. 1 provided with such an ink jet head 5, the discharge port line 23, and hence the arrangement direction of the coating material discharge ports 22, is adjusted to be parallel to the X-axis direction.

  Each coating material storage chamber is provided with a discharge mechanism section (not shown) composed of a piezoelectric element or the like. By applying a voltage to the discharge mechanism section and operating it, coating in the coating material storage chamber is performed. The material is discharged as fine droplets from the coating material discharge port 22. In addition, as a discharge mechanism part, the mechanism etc. which apply not only a piezoelectric element system but an air pressure may be sufficient.

  In the first embodiment, in addition to the coating mechanism unit A, an inkjet head inspection mechanism unit for inspecting the coating material discharge port 22 of the inkjet head 5 is provided, and the inkjet head 5 is used in the coating mechanism unit A. In doing so, each of the coating material discharge ports 22 is inspected by the ink jet head inspection mechanism. Hereinafter, the inkjet head inspection mechanism will be described assuming that the inkjet head inspection mechanism is separate from the coating mechanism.

  FIG. 3 shows one specific example of such an ink jet head inspection mechanism, wherein FIG. 3A is a perspective view showing the configuration of the main part, FIG. 3B is a circuit configuration diagram, and B is an ink jet. Head inspection mechanism (hereinafter simply referred to as inspection mechanism), 25 is a Y-axis stage, 26 is a Y-axis drive motor, 27 is an X-axis stage, 28 is an X-axis drive motor, 29 is a θ-direction rotation unit, and 30 is a camera , 31 is a light source, 32 is a tray, 33 is a cleaning device, 34 is an optical axis, 35 is a Z-axis stage, 36 is a Z-axis drive motor, 37 is a head bracket to which the inkjet head 5 is attached, 38 is a head drive substrate, 39 Is a light source control device, and 40 is a droplet. Note that portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  A specific example of the inspection mechanism unit basically has the same configuration as the coating mechanism unit A shown in FIG.

  In FIG. 3A, an X-axis stage 27 is mounted on a Y-axis stage 25 fixedly attached to a gantry (not shown) so as to be movable in the Y-axis direction with respect to the Y-axis stage 25 by a Y-axis drive motor 26. A θ-direction rotating unit 29 is mounted on the X-axis stage 27 so as to be movable in the X-axis direction with respect to the X-axis stage 27 by an X-axis drive motor 28. The θ-direction rotating unit 29 is rotated in the θ direction by a drive motor (not shown). The configuration of the inspection mechanism B is the same as that of the coating mechanism shown in FIG.

  On the θ-direction rotating unit 29, a tray 32 having a frame around it is fixedly attached. The camera 30 is provided on the end face of one of the two opposing sides of the tray 32 and the light source 31 is provided on the end face of the other side so as to face each other. The camera 30 and the light source 31 are arranged so that the optical axis of the light source 31 coincides with the optical axis 34 (which is perpendicular to the imaging surface and perpendicular to the imaging surface). Further, a cleaning device 33 for the ink jet head 5 is provided on the end face of the other one side of the tray 32.

  Further, the above-described frame (not shown) is provided with a gate-type frame similar to the frame 2 shown in FIG. 1, and this is provided with a head drive substrate 38 (FIG. 3) in the same manner as the coating mechanism portion A shown in FIG. (B)) and a Z-axis stage 35 having a Z-axis drive motor 36 are provided, and a head bracket 37 movable in the Z-axis direction is attached to the Z-axis stage 35, and the head bracket 37 is to be inspected. The inkjet head 5 is detachably attached.

  In the inspection mechanism part B of this specific example, a PC and a monitor are further used. Here, the PC 20 and the monitor 19 used in the coating mechanism part A shown in FIG. .

  When inspecting the performance of the inkjet head 5 by the inspection mechanism B, the optical axis 34 from the camera 30 to the light source 31 is moved in the Y-axis direction by rotating the θ-direction rotating unit 29 to rotate the tray 32. Therefore, the postures of the camera 30 and the light source 31 are adjusted so that the optical axis 34 is perpendicular to the discharge port line 23 (FIG. 2) in the inkjet head 5 so as to be parallel. Then, by appropriately driving the Y-axis drive motor 26 and the X-axis drive motor 28, the ejection path of the droplets ejected from the ejection surface (bottom surface) 5a (FIG. 2) of the inkjet head 5 is changed to the camera 30 and the light source 31. The positions of the tray 32 in the X-axis direction and the Y-axis direction are adjusted so as to be in between.

  Here, as shown in FIG. 4, the height h of the field of view 30a of the camera 30 is an inkjet from the coating surface of the coating substrate 8 when the coating material 8 is coated on the coating substrate 8 by the coating mechanism A shown in FIG. It is assumed that it is higher than the height of the ejection surface 5a (FIG. 2) of the head 5 (head height H1 described later).

  When inspecting the inkjet head 5, as shown in FIG. 4, by driving the Z-axis drive motor 36, the ejection surface 5a (FIG. 2) of the inkjet head 5 is positioned substantially on the upper side of the visual field 30a. Next, the height of the inkjet head 5 is adjusted. By adjusting in this way, a position slightly higher than the lower side in the visual field 30a becomes a position corresponding to the application surface 8a of the application substrate 8 with respect to the ejection surface 5a of the inkjet head 5 when applying the application material.

  When this adjustment is completed, the coating material is ejected one by one in the arrangement order from the coating material ejection port 22 of the inkjet head 5, and the droplets of the coating material ejected thereby are illuminated by the light source 31 and imaged by the camera 30. . The image signal of the imaged droplet is sent to the PC 20 for various image processing for inspection. In this way, the size, shape, position, etc. of the droplets of the coating material can be observed. The droplets ejected in this way are received by the tray 32. Further, the clogging factor of the coating material discharge port 22 of the inkjet head 5 is caused by appropriately driving the Y-axis drive motor 26 and the X-axis drive motor 28 to move the inkjet head 5 to the head cleaning device 33. Can be removed.

  Note that when the droplets discharged from all the coating material discharge ports 22 of the inkjet head 5 cannot fit within the horizontal width of the visual field 30a of the camera 30, the coating material discharge ports 22 for discharging the coating material are used. As the X-axis drive motor 28 is driven from one side of the row of the outlets 22 to the other side, the tray 32, and hence the camera 30 and the light source 31, and the camera 30 picks up droplets from any coating material discharge port 22. It can be so. Further, when the droplets discharged from all the coating material discharge ports 22 of the inkjet head 5 fall within the field of view of the camera 30, the optical axis 34 crosses the center of the row of the coating material discharge ports 22. By adjusting the positions of the camera 30 and the light source 31, the positions of the camera 30 and the light source 31 can be fixed and placed during the droplet imaging period. Here, even if the positional relationship between the camera 30 and the light source 31 and the inkjet head 5 is set, or even when the droplet is captured by the camera 30 as described above, the camera 30 and the light source 31 are used. Although moved, the inkjet head 5 may be moved by making the inkjet head 5 movable in the X-axis direction.

  Next, discharge control of the coating material from the inkjet head 5 and light emission control of the light source 31 will be described with reference to FIG.

  When the droplet 40 is ejected from the inkjet head 5, the ejection command is output from the PC 20. Upon receiving this ejection command, the head drive substrate 38 converts the ejection command into ejection commands for each coating material ejection port 22 (FIG. 2) on the ejection surface 5a of the inkjet head 5, and these ejection commands are sequentially arranged at predetermined time intervals. To send. Thereby, in the inkjet head 5, the discharge command concerning each coating material storage chamber is transmitted to each coating material storage chamber in sequence, and each discharge mechanism operates, so that the coating material discharge port 22 of these coating material storage chambers causes a predetermined time. The droplets 40 are discharged in the order in which discharge commands are supplied at intervals.

  The discharge command for each coating material discharge port 22 is also sent to the light source control device 39. Each time the light source control device 39 receives this ejection command, it causes the light source 31 to emit light for a sufficiently short period of time with a specified delay time from the timing at which the ejection command is received. Thereby, one droplet 40 ejected from one of the coating material ejection ports 22 is illuminated, and the state of the droplet 40 at the moment of illumination is imaged by the camera 30. Such imaging is sequentially performed for each coating material discharge port 22.

  The delay time defined by the light source control device 39 is the length of time from when the droplet 40 starts to be discharged from the coating material discharge port 22 until the droplet 40 passes through the visual field range of the camera 30. Thus, from the moment when the droplet 40 starts to be ejected from the coating material ejection port 22 (delay time = 0), the droplet 40 just passes through the visual field range of the camera 30. The light source 31 can emit light instantaneously at an arbitrary timing until the moment, and when the droplet 40 is falling in the field of view of the camera 30, it is illuminated by the light source 31 at that arbitrary moment and is imaged by the camera 30. Can do.

  As described above, the imaging by the camera 30 is performed, so that it is possible to capture the liquid droplet 40 in a state of being stationary in the air, and more specifically, a plurality of times from the same coating material discharge port 22. By performing the ejection and sequentially changing the above-mentioned delay time for each ejection to sequentially vary the light emission timing of the light source 31, it is possible to obtain a captured image at the sequential timing of the ejected droplets 40. This makes it possible to observe the state of the droplet 40, the drop distance, the flight angle, and the like.

  FIGS. 5A and 5B are diagrams showing a specific example of the coating substrate 8 used in the first embodiment shown in FIG. 1 and the coating state of the coating material, and 41 is a bank (recessed portion). Yes, parts corresponding to those in the previous drawings are given the same reference numerals.

  5 (a) and 5 (b), for example, an oval bank 41 having a prescribed width W, depth L, and depth H2 (FIG. 6) is formed on the coated substrate 8 used for an EL device or the like at a constant interval. In a square matrix. The coated substrate 8 shown in FIG. 5 (a) and the coated substrate 8 shown in FIG. 5 (b) are different from each other in the direction of the bank 41, for example, by 90 degrees. . Here, any coated substrate 8 may be used.

  Normally, a plurality of banks 41 having different shapes are formed on the coated substrate 8, and an aggregate is formed for each bank 41 of the same shape. Here, only one aggregate is shown, and the other The set of is omitted. Here, the discharge port line 23 (FIG. 2) of the inkjet head 5 is parallel to the arrangement of the banks 41 in the X-axis direction, and each of the coating material discharge ports 22 (FIG. 2) on the discharge port line 23 is one. In a state where one of the banks 41 is arranged opposite to each other in the X-axis direction, the droplets 40 are discharged from the coating material discharge ports 22 of the inkjet head 5 one by one in a specified order. Controlled to land on.

  When the application of the coating material in the bank 41 for one column in the X-axis direction is completed, the coating substrate 8 moves in the Y-axis direction by the pitch in the Y-axis direction of the bank 41 and the next bank for one column in the X-axis direction. The application material is applied at 41. In this way, the coating material is sequentially applied to the banks 41 for each row in the X-axis direction. Alternatively, the position may be detected in real time by using a distance detection means such as a linear scale while moving in the Y-axis direction, and the coating material may be applied to continuously apply the position.

  FIG. 6 is a diagram showing the relationship between the flying angle of the droplet 40 from the inkjet head 5 and the variation in the landing position, and shows a cross section along the Y-axis direction. The same reference numerals are given.

  In the figure, the amount of droplets 40 ejected into one bank 41 is determined in advance, and this is the ideal droplet amount. The height of the liquid surface of the coating material 42 in the bank 41 from the bottom surface of the bank 41 when the droplet 40 having the ideal droplet amount has landed in the bank 41 and spread uniformly is defined as H3. If the ideal trajectory of the droplet 40 ejected from the inkjet head 5 is the trajectory 43 and the actual trajectory is the trajectory 44, the trajectories 43 and 44 do not coincide with each other, and a flying angle θY is generated. Assuming that the distance between the coating material discharge port 22 and the surface of the coating substrate 8 at this time is the head height H <b> 1, the actual locus 44 from the landing point 45 of the droplet 40 on the bank 41 by the ideal locus 43. A landing error ΔY of the droplet 40 in the Y direction due to the landing point 46 being shifted occurs. Here, if the Y-direction landing error ΔY is larger than the Y-direction allowable landing error ΔYT, the liquid droplet 40 does not land on the bank 41. In the worst case, the liquid droplets land on the adjacent bank 41 (not shown). Will do. In such a case, the coating material discharge port 22 of the corresponding inkjet head 5 is not used, or the head height H1 is lowered to reduce the Y-direction landing error ΔY.

  Here, the width W direction (Y direction) of the bank 41 is described, but the same applies to the depth L direction (X direction) of the bank 41.

  The allowable landing error ΔYT is affected by the shape (width W) of the bank 41, but may be determined in consideration of the viscosity and specific weight of the droplet 40 and the hydrophilicity of the bank 41.

  Furthermore, when the droplet 40 lands and spreads and spreads in the bank 41, if the droplet 40 falls too quickly or the droplet 40 is not sufficiently stable as described later, the droplet after landing. It is known that not only the behavior of 40 is not stable, but also a part of the total amount of the droplet 40 gets over the bank 41 due to the inertial force developed in all directions at the time of landing and adheres to an unintended region in the coated substrate 8. It is also preferable to consider these with respect to the allowable landing error ΔYT.

  FIG. 7 is an explanatory view of the outline of the satellite and the gap length H0 in the first embodiment.

  In the figure, the coating material ejected from the coating material ejection port 22 of the inkjet head 5 has a spherical shape (P2 → P3) after a short time from immediately after ejection (P1), and eventually its own weight and viscosity. As a result, the droplet 40 is completely separated from the coating material discharge port 22 (P4), becomes spherical (P5), and its internal stress gradually diverges and stabilizes (P6). The distance from the coating material discharge port 22 of the inkjet head 5 at that time to the center of the droplet 40 when stabilized is the gap length H0. The droplet 40 that has reached the position of the gap length H0 is stabilized. By setting the head height H1 (FIG. 6) from the coating surface of the coating substrate 8 to be equal to or greater than the gap length H0, the droplet 40 is formed. The bank 41 can be landed in a stable state. That is, it is preferable that the head height H1 is set to be equal to or larger than the gap length H0 so that the droplet 40 reaches the bank 41 in such a stable state.

  Here, by applying a voltage to each coating material discharge port 22 of the inkjet head 5, a discharge mechanism such as a compression element in the coating material storage chamber for each coating material discharge port 22 (FIG. 3) in the inkjet head 5. The coating material is ejected from the coating material ejection port 22 and the droplet 40 is generated. When the applied voltage is set to a specified voltage value or more and the droplet 40 is ejected, the droplet 40 is ejected around the droplet 40. A plurality of micro droplet groups (satellite) 47 having a slower speed than the droplet 40 is generated (P5 ′ → P6 ′ in FIG. 7). Since the generation of the satellite 47 causes the quality of the organic EL device or the like to be remarkably deteriorated, as will be described later, at an applied voltage for generating the satellite 47 or an applied voltage higher than that, the coating material is discharged from the coating material discharge port 22. Do not discharge.

  FIG. 8 is a diagram showing the relationship between the droplet amount Q and the applied voltage E in the inkjet head 5 in the first embodiment. The voltage application time is the same for each coating material discharge port 22.

  In FIG. 8A, the possible upper limit value and lower limit value of the applied voltage E in the inkjet head 5 are determined in advance. Within the range between the upper limit value and the lower limit value, in particular, the minimum applied voltage capable of ejecting the droplet 40 is E1, and the amount of droplet 40 (droplet amount Q) at that time is Q1. Further, the maximum applied voltage capable of ejecting the droplet 40 is E2, and the droplet amount Q at that time is Q2. Between the applied voltages E1 and E2, it is known that the applied voltage E and the ejected droplet amount Q are in a proportional relationship (note that satellites are not included in the droplet amount Q), and a straight line representing the proportional relationship is shown. The discharge characteristic line 48 is used. As described above, when a high voltage E is applied to the inkjet head 5, the satellite 47 (FIG. 7) is generated around the ejected droplets. The applied voltage E generated by the satellite 47 for the first time is set as the allowable maximum applied voltage ES. Then, the voltage band between the voltages ES and E2 is not used. The optimum applied voltage ET is an applied voltage E that can eject droplets 40 of the optimum droplet amount QT (corresponding to a predetermined ideal droplet amount ejected to the bank 41 described in FIG. 6). In the inkjet head 5 used in the coating mechanism section A shown in FIG. 1, as the optimum applied voltage E, an optimum applied voltage ET capable of ejecting a predetermined optimum droplet amount QT from the voltage E1-ES is selected. become.

  On the other hand, if the ink jet head 5 is continuously used, the discharge characteristic line 48 gradually descends to become the discharge characteristic line 49 as shown in FIG. Can no longer be discharged. In some cases, the discharge characteristic straightness 49 may be caused from the beginning due to the difference in solids of the inkjet head 5. In such a case, the same bank 41 is applied twice or more so that the droplets 40 having the optimum droplet amount QT can be secured in the bank 41.

  In FIG. 8B, for example, when the droplet quantity Q that is half of the optimum droplet quantity QT is the divided optimum droplet quantity QTh, the applied voltage E and the ejected droplet quantity Q are in a proportional relationship. An application voltage ETh with respect to the optimum droplet amount QTh is applied twice to the same bank 41 and applied twice. As a result, it is possible to ensure the application with the optimum droplet amount QT (= 2 × QTh) droplet amount Q in the bank 41.

  Note that, at an applied voltage E smaller than the applied voltage E1, an operation for ejecting the coating material is actually performed by the inkjet head 5, but there is not enough force to eject the coating material. Material is not discharged to the outside. However, even with such an applied voltage E, when the applied voltage is relatively close to the minimum applied voltage E1, in the coating material storage chamber of the inkjet head 5, the coating material is agitated and oscillated by the operation of the discharge mechanism. The applied voltage E at this time is set as the oscillation voltage E0. In the ink jet head 5, when the coating material discharge operation is not performed for a long time, the coating material discharge port 22 is gradually dried and clogging occurs. On the other hand, although sufficient discharge characteristics cannot be exhibited, if the swing application voltage E0 is continuously applied (swings) to the inkjet head 5, the coating material is in the vicinity of the coating material discharge port 22 of the inkjet head. It has been found through experiments by the inventors that the coating material discharge port 22 is not clogged with sufficient stirring in the flow path. In addition, when the coating material is swung, the coating material is not ejected from the inkjet head 5, so that it can be said that the ejection operation is virtually not performed. Therefore, when the ink jet head 5 does not perform the discharge operation, the applied voltage is always set to the swing voltage E0. Further, the swing voltage E0 is more preferably close to the minimum applied voltage E1.

  Next, determination of various parameters for actually ejecting the droplets 40 having the optimum droplet amount QT by the inkjet head 5 using the inspection mechanism section B shown in FIGS. 3A and 3B will be described.

  9 is a flowchart showing a specific example of the overall operation of the inspection mechanism B for this purpose, FIG. 10 is a flowchart showing a specific example of step 103 in FIG. 9, and FIG. 11 is a specific example of step 109 in FIG. It is a flowchart which shows an example. Hereinafter, a description will be given with reference to FIGS.

  9, first, in preparation for measurement, the bank width in FIGS. 5 and 6 is used as a specification of the bank 41 (FIG. 5) on the coating substrate 8 used in the coating mechanism section A shown in FIG. W, bank depth L, Y-direction allowable landing error ΔYT, X-direction allowable landing error ΔXT (not shown), required droplet amount, and allowable divided application number are input. Further, as the specifications of the inkjet head 5, the gap length H0 (FIG. 7), the head height H1 (FIG. 6), and the number of allowable defective ejection ports are input. Note that the X-direction allowable landing error ΔXT and the Y-direction allowable landing error ΔYT may be determined by the PC 20 using a unique calculation formula from the bank width W and the head height H1, or the like. A numerical value may be input (step 101).

  Further, in the inspection mechanism section B shown in FIG. 3, the inkjet head 5 used in the coating mechanism section A shown in FIG. 1 is attached to the head bracket 37, and the Z-axis stage 35 is driven to set the position at a predetermined position where inspection can be performed. To do. Then, after rotating the θ-direction rotating unit 29 and adjusting the direction of the optical axis 34 so that the optical axis 34 of the camera 30 and the light source 31 is orthogonal to the discharge port line 23 (FIG. 2), the PC 20 Then, an applied voltage and a drive signal for preparation for inspection are transmitted from the inkjet head 5 to eject the coating material from the coating material ejection port 22 (FIG. 2). This discharge is performed sequentially for each coating material discharge port 221. The camera 30 picks up an image of the droplet 40 generated by the discharge of the coating material, and drives the X-axis drive motor 28 together with the camera 30 so that the droplet 40 discharged from the inkjet head 5 falls within the field of view of the camera 30. Is adjusted in the X-axis direction. When the droplets 40 from all of the coating material discharge ports 22 of the inkjet head 5 cannot fit within the field of view of the camera 30, at least the first droplet 40 to be discharged (for example, the leftmost coating material discharge port 22). The position of the camera 30 is adjusted so that the droplets 40) ejected from the camera fall within the field of view. If necessary, the position of the camera 30 in the Y-axis direction may be adjusted by driving the Y-axis drive motor 26 to adjust the focus of the camera 30 (step 102 in FIG. 9).

  Thus, the preparation work for measurement is completed. In the first embodiment, the droplets 40 discharged from all the coating material discharge ports 22 of the ink jet head 5 are to be inspected, and the rightmost coating material discharge port in order from the leftmost coating material discharge port 22. The number of droplets 40 to be discharged is measured up to 22, but the number of discharge ports to be inspected can be arbitrarily determined, and the order of measurement can also be arbitrarily determined.

  In FIG. 9, when the above preparatory work is completed, next, data relating to the behavior of the droplet 40 necessary for obtaining the ejection characteristics of the inkjet head 5 is acquired (step 103). This will be described with reference to FIG.

  In the figure, first, one of the coating material discharge ports 22 provided in the inkjet head 5 (in this case, the leftmost coating material discharge port 22) is selected and the inspection target discharge port 22 is selected. A small applied voltage (voltage having a voltage value smaller than the minimum applied voltage E1 shown in FIG. 8A) E is set as an initial drive voltage for inspection of the inkjet head 5 (step 201), and the light source control device The delay time Td of the light emission timing of the light source 31 with respect to the ejection command set at 39 (FIG. 3B) is set to Td = 0 (step 202). Then, the set applied voltage E is applied to the inspection target discharge port 22 of the inkjet head 5 and imaged by the camera 30 to monitor the discharge state of the liquid droplet (step 203). When the light source 31 emits light instantaneously before being discharged from the target discharge port 22, or when the applied voltage E is less than the above-mentioned minimum applied voltage E1 (FIG. 8A), the camera 30 causes the droplet 40 to be discharged. Cannot be captured (step 204), the process proceeds to steps 206 and 208, and a predetermined time ΔTd is added to the delay time Td currently set in the light source control device 39 (in this case, Td = 0). Then, the light source 31 is caused to emit light with a new delay time Td + ΔTd, and the camera 30 performs an image. In this manner, the operations of steps 203, 204, 206, 208, 210, and 211 are repeated until the camera 30 images the droplet 40 by illumination of the light source 31 (step 204). Thus, the delay time Td increases by a predetermined time ΔTd.

  However, the discharge standby time in which the delay time Td set in the light source control device 39 is set in advance (the time from when the droplet 40 starts to discharge from the inspection target discharge port 22 until it passes through the visual field of the camera 30). If the droplet 40 is not ejected from the inspection target ejection port 22 even if the value exceeds this value (step 211), the applied voltage E at this time is less than the minimum applied voltage E1, and the droplet 40 was not ejected. The applied voltage E to the inspection target discharge port 22 is increased by a predetermined voltage ΔE (step 212). Then, the process returns from step 213 to step 202, the delay time Td in the light source control device 39 is returned to 0, and the above operation is repeated with the applied voltage E + ΔE.

  In this manner, the above operation is repeated until the camera 30 can image the droplet 40 by illumination of the light source 31 (step 204), and the applied voltage E of the inspection target ejection port 22 is incremented by a predetermined voltage ΔE for each repetition. The delay time Td is increased by the predetermined time ΔTd by the light source control device 39 during the period when the applied voltage E set at that time is applied to the inspection target ejection port 22.

  When such an operation is repeated and thereafter the discharge of the droplet 40 from the inspection target discharge port 22 is confirmed (step 204), the applied voltage E at this time is set to the minimum value of the inspection target discharge port 22. The applied voltage E1 is recorded on the PC 20 (step 205).

  As described with reference to FIG. 7, the droplet 40 is stabilized as time elapses after being ejected from the coating material ejection port 22, but the PC 20 is captured by the camera 30 from the image signal from the camera 30. It is determined whether or not the droplet 40 is stable (step 206).

  When the droplet 40 is not stable, the operations of steps 203 to 206, 208, 210, and 211 are repeated, and the delay time Td is increased by the predetermined time ΔTd by the light source control device 39 each time the operation is repeated. In step 205, since the minimum applied voltage E1 has already been recorded, the minimum applied voltage E1 is no longer recorded and is simply passed as it is.

  As described above, the delay time Td sequentially increases by the predetermined time ΔTd, the light emission timing of the light source 31 is delayed, and the light source 31 illuminates the droplet 40 when the discharged droplet 40 is stabilized, This is imaged by the camera 30, and the PC 20 determines that the droplet 40 is stable (step 206). Thus, the PC 20 calculates the center coordinates of the droplet 40 in the field of view of the camera 30 based on the delay time Td set by the light source control device 39 and the contour of the captured droplet 40 at that time. In addition, based on the contour of the droplet 40, the volume of the droplet 40 (in this case, since it is stable, it has a spherical shape), that is, the amount of the droplet is calculated, and the droplet 40 And the information (number etc.) for specifying the inspection target discharge port 22 together with the applied voltage E to the inspection target discharge port 22 and the delay time Td in the light source control device 39 at this time. It records in association (step 207).

  Thereafter, the operations of Steps 203 to 208, 210, and 211 are repeated, and the delay time Td is increased by a predetermined time ΔTd by the light source control device 39 every time the operation is repeated. Meanwhile, in step 207, the above data is recorded. When the delay time Td exceeds the discharge standby time (step 211), the voltage E applied to the inspection target discharge port 22 is increased by a predetermined voltage ΔE. While the above operation is repeated, the above data is recorded in step 207.

  By the way, as described with reference to FIGS. 7 and 8, satellites 47 are generated around the droplets 40 when the applied voltage E exceeds a certain voltage value after the start of droplet ejection is confirmed. Therefore, when the generated satellite 47 is illuminated by the light source 31 and is imaged by the camera 30 by repeating the above operation, the PC 20 determines that the satellite 47 is generated around the droplet 40 (step 208). The applied voltage E immediately before the applied voltage E at that time is applied to the PC 20 as the maximum applied voltage at which the satellite 47 for the inspection target discharge port 22 is not generated, that is, the allowable maximum applied voltage ES shown in FIG. Record (step 209) and proceed to step 104 in FIG.

  Even if at least the satellite 47 is observed (step 208), the process proceeds to step 104 in FIG. 9 even when the applied voltage E at the inspection target discharge port 22 exceeds the maximum applied voltage E2 shown in FIG. In this case, the maximum applied voltage E2 becomes the allowable maximum applied voltage ES of the inspection target discharge port 22.

  In steps 204, 206, and 208, in the first embodiment, the above-described various parameters are extracted from the image information of the droplet 40 obtained by one imaging and sequentially recorded in the PC 20, but the same delay is used. The droplet 40 may be imaged twice or more at time Td, and the average of various parameters obtained by each imaging may be recorded in the PC 20.

  Further, in the operation described above with reference to FIG. 10, the droplets 40 are sequentially ejected from the coating material ejection port 22 of the inkjet head 5, and the camera 30 images the droplets 40 from the coating material ejection port 22 one by one. However, a plurality of coating material discharge ports 22 in the field of view of the camera 30 may simultaneously discharge the droplets 40, and these may be simultaneously imaged to acquire respective data.

  In FIG. 9, when the above parameters are obtained for the inspection target ejection port 22 in step 103, the θ direction rotation unit 29 is then rotated 90 degrees, and the optical axis 34 of the camera 30 and the light source 31 is changed to the inkjet head. 5 is adjusted so as to be parallel to the discharge port line 23 (FIG. 2) (step 104). For the same discharge port 22 to be inspected, the same parameters as in step 103, that is, the data regarding the behavior of the droplet 40 are stored. Measurement is performed (step 105).

  As described above, data regarding the behavior of the droplet 40 when viewed from the Y-axis direction and data regarding the behavior of the droplet 40 when viewed from the X-axis direction are obtained for one coating material discharge port 22.

  Thereafter, if necessary, the inspection target discharge port 22 and its peripheral portion are cleaned by the cleaning device 28 (step 107). Thereby, the operation for the inspection target discharge port 22 is completed. Then, one of the other coating material discharge ports 22 that is not the inspection target is selected as the next inspection target discharge port 22 (step 107). A series of operations are performed, and data relating to the behavior of the droplet 40 discharged from the inspection target discharge port 2 as seen from the X-axis and Y-axis directions is acquired.

  In this way, data related to the behavior of the droplets 40 discharged from each coating material discharge port 22 is acquired in sequence, and acquisition of data related to the behavior of the droplets for all the coating material discharge ports 22 is completed (step 106). Next, the obtained data of each coating material discharge port 22 is evaluated, and various parameters necessary for using the inkjet head 5 in the coating mechanism part A are determined (step 109). This will be described with reference to FIG.

  In the figure, first, an applied voltage E for ejecting the same amount of droplets 40 from each coating material ejection port 22 of the inkjet head 5 when used in the coating mechanism A (FIG. 1) is determined. (Step 301), this is done as follows. Note that, in each coating material discharge port 22, the amount of discharged droplets varies with the same applied voltage E, but in this step 301, the amount of droplets in all the coating material discharge ports 22 becomes equal. Thus, each applied voltage E is determined.

  That is, among the parameters recorded in the PC 20, for each coating material discharge port 22, each applied voltage E obtained at step 207 in FIG. 10 and the droplet amount at that time (hereinafter referred to as measured droplet amount). And the required droplet amount (corresponding to the optimum droplet amount QT in FIG. 8A) already input to the PC 20 in step 101 of FIG. 9 for each proportional relationship equation. By substituting, the applied voltage E corresponding to this required droplet amount is obtained, and this is applied to the PC 20 as the optimum applied voltage ET (n) (where n is the number of the coating material discharge port 22) shown in FIG. Record sequentially. As described above, the optimum applied voltage ET (n) for each coating material discharge port 22 of the inkjet head 5 used in the coating mechanism portion A shown in FIG. 1 is determined and recorded in the PC 20.

  In addition, without using a proportional relational expression, a droplet amount allowable error (for example, within ± 5%) is provided, and an allowable droplet determined by the droplet amount allowable error of the required droplet amount for each coating material discharge port 22. The applied voltage E corresponding to the measured droplet amount falling within the amount range (that is, within the required droplet amount ± 5%) may be sequentially recorded on the PC 20 as the optimum applied voltage ET (n).

  When the measured droplet amount corresponding to the required droplet amount cannot be found, specifically, in the case where the droplet amount in the bank 41 (FIG. 5) is insufficient in one discharge of the droplet 40, the same It is assumed that the droplets 40 are ejected into the bank 41 in two times, and the respective applied voltages E are selected so that the sum of the two actually measured droplet amounts becomes the required droplet amount, and the respective applied voltages E are set. The optimum applied voltages ETa (n) and ETb (n) are recorded on the PC 20.

  Further, the discharge of the droplets 40 may be divided into three or more times with respect to the same bank 41 as described above, but this number does not exceed the allowable divided application number input in step 101 in FIG. Even if the droplets 40 are ejected to the same bank 41 by the allowable number of times of division coating, if the amount of droplets is less than the required droplet amount, the coating material ejection port 22 is used in the coating mechanism A (FIG. 1). This is recorded on the PC 20 as defective ejection ports, and the number is counted as the number of defective ejection ports. The number of defective ejection ports is 0 when inputting in step 101 of FIG.

  When the optimum applied voltage ET (n) of each coating material discharge port 22 is determined so that the variation in droplet amount is corrected as described above in step 301 of FIG. For each coating material discharge port 22, the landing accuracy of the droplet 40 on the bank 41 of the coating substrate 8 is determined when the obtained optimum applied voltage ET (n) is the applied voltage E (step 302). This landing accuracy varies for each coating material discharge port 22. This will be described below. In addition, about the coating material discharge port 22 determined to be a defective discharge port by step 301, the determination may be abbreviate | omitted.

  For each coating material discharge port 22, this center coordinate is obtained from the data of the center coordinate for each delay time Td of the droplet 40 at the optimum applied voltage ET (n) obtained in step 301 of FIG. 11 and recorded in the PC 20. Is obtained by linear approximation (corresponding to the actual trajectory 44 in FIG. 6), and the linear trajectory when the droplet 40 falls vertically (corresponding to the ideal trajectory 43 in FIG. 6). 6), the flight angle θY (n) (where n is the number of the coating material discharge port 22) is obtained, and the flight angle θY (n) is already sent to the PC 20 in step 101 of FIG. From the input surface of the coating substrate 8 to the ejection surface 5a (FIG. 2) of the inkjet head 5, that is, the head height H1, a coating material ejection port 22 as shown in FIG. Unique Y-direction landing error ΔY (n) (where n is Determine the number) of cloth material discharge port 22.

  If the Y-direction landing error ΔY (n) thus determined exceeds the Y-direction allowable landing error ΔYT input to the PC 20 in step 101 of FIG. 9, the head height H1 is set low. The Y-direction landing error ΔY (n) is calculated again. This process is repeated until the Y-direction landing error ΔY (n) is equal to or less than the Y-direction allowable landing error ΔYT. When this occurs, the head height H1 (n) (however, n Is the number of the coating material discharge port 22) and the Y direction landing error ΔY (n) are recorded on the PC 20. The same applies to the X-direction landing error ΔX, and the X-direction landing error ΔX (n) at the head height H1 (n) is obtained and recorded on the PC 20.

  In the first embodiment, the head height H1 (n) is set so as not to fall below the gap length H0 (FIG. 7). Therefore, in order for the Y-direction landing error ΔY (n) to be equal to or less than the Y-direction allowable landing error ΔYT, the head height H1 (n) must be less than the gap length H0. The discharge ports 22 are not used in the coating mechanism part A (FIG. 1), and that effect is recorded on the PC 20 and the number thereof is counted as the number of defective discharge ports.

  In this way, when the head height H1 (n) for correcting the Y-direction landing error ΔY (n) and the variation in the landing position of the droplet 40 is determined for each coating material discharge port 22 in FIG. Next, the swing voltage E0 when the coating mechanism A performs the coating material coating operation on the coating substrate 8 is determined (step 303). This will be described next.

  First, the minimum applied voltage E1 at all the coating material discharge ports 22 measured in step 205 in FIG. 10 is referred to, and the lowest minimum applied voltage E1 is selected among them. Then, the voltage obtained by subtracting the prescribed voltage ΔE for increasing the applied voltage E used in step 212 in FIG. 10 is set as the oscillation voltage E0, and this is recorded in the PC 20.

  In FIG. 11, it is next determined whether or not the ink jet head 5 used for the inspection can be used in the coating mechanism A (step 304). It is determined whether or not the total number of defective ejection ports counted in steps 301 and 302 in FIG. 11 is equal to or larger than the allowable number of defective ejection ports input in step 101 in FIG. 9 (step 305). If it is less than this, it can be used as it is, and the process proceeds to step 110 in FIG. The process proceeds to step 110 in FIG.

  Thus, the inspection of the ink jet head 5 is completed, and the inspected ink jet head 5 is removed from the head bracket 37 of the inspection mechanism B (FIG. 3) (step 110). The usable inkjet head 5 is attached to the head bracket 6 of the coating mechanism part A (FIG. 1) and used for coating work on the coating substrate 8.

  The parameters used for the coating operation in the coating mechanism section A are recorded on the PC 20 as described above, and among the parameters, the optimum applied voltage ET (n) for each coating material discharge port 22 (the same bank 41 of the coating substrate 8 ( For the coating material discharge port 22 designated to perform coating a plurality of times in FIG. 5), the optimum applied voltage ETa (n), ETb (n),...) And the head height H1 (n) for each. Data indicating the smallest value in the set and defective outlets. The PC 20 controls the applied voltage and the like at the inkjet head 5 with such parameters.

  In the first embodiment, the same PC 20 is used in the application mechanism A (FIG. 1) and the inspection mechanism B (FIG. 3). However, separate PCs may be used. In this case, however, a data link mechanism such as a LAN or parallel connection is provided between the PCs so that data such as parameters acquired by the PC of the inspection mechanism part B can be transferred to the coating mechanism part A. An external recording device is mounted on the PC of each mechanism unit, the data recorded on the PC of the inspection mechanism unit B is recorded on the recording medium by the external recording device, and this recording medium is recorded on the external recording device by the coating mechanism unit A. The data is mounted and used by the PC on the coating mechanism A side.

  Next, the operation in the case where the inkjet head 5 ejects the optimum liquid droplets when applying the coating material to the coating substrate 8 by the coating mechanism portion A shown in FIG. 1 will be described.

  FIG. 12 is a flowchart showing a specific example of the coating operation of the coating mechanism A shown in FIG.

  In the figure, as preparation for coating, first, a head protection device (not shown) attached to the inkjet head 5 to be used is removed and attached to the inspection mechanism B shown in FIG. This head protection device is for preventing clogging due to drying of the coating material discharge port 22 of the inkjet head 5. Then, in the application mechanism part A, the PC 20 is started, the application material in the application material bottle 16 and the remaining amount of the cleaning solvent in the cleaning liquid bottle 18 are confirmed, and self-diagnosis of each component device is performed (step) 401).

  On the other hand, in the inspection mechanism section B, the cleaning device 133 cleans the coating material discharge port 22 (FIG. 2) of the ink jet head 5 and its peripheral portion to eliminate the clogging factor (step 402). Thereafter, as described above, the inkjet head 5 is inspected and the parameters necessary for the coating operation are acquired in the PC 20 (step 403).

  Subsequently, the PC 20 reflects such parameters in the future application work. That is, the inspected inkjet head 5 is attached to the head bracket 6 of the coating mechanism part A, the Z-axis stage 3 is driven, and the distance between the ejection port surface 5a (FIG. 2) of the inkjet head 5 and the coating surface of the coating substrate 8. That is, the head height is set to the smallest value among the set of head heights H1 (n) of the coating material discharge ports 22 (FIG. 2) obtained by the above inspection. As a result, the X direction landing error ΔX (n) and the Y direction landing error ΔY (n) fall within the range of the X direction allowable landing error ΔXT and the Y direction allowable landing error ΔYT, respectively, at all the coating material discharge ports 22. Thus, any coating material discharge port 22 that is not determined to be defective in the above inspection can be used.

  At the same time, the coating substrate 8 transported from the pre-deposition processing step or the like is placed on a predetermined position of the suction table 14, and a vacuum generating means (not shown) is driven to fix the coating substrate 8 by suction (step 404). . Then, each coating material discharge port 22 of the inkjet head 5 is made to face the bank 47 (FIG. 5) on the coating substrate 8, and the optimum applied voltage ET (n) is set for each coating material discharge port 22 of the inkjet head 5. Apply. As a result, the droplet 40 of the coating material is discharged from each coating material discharge port 22, and the coating material is applied to each bank 47. If the inkjet head 5 to be used has a defective discharge port, the operation method is changed (step 405) such that the application operation by the discharge port is not performed and the other coating material discharge port 22 is substituted. In this way, when the application on the application substrate 8 is completed, a vacuum generating means (not shown) is driven to release the application substrate 8 from the suction table 14 and transport it to the next post-application process (step 406).

  When the coating operation on one coating substrate 8 is completed in this way, the prescribed number of coating substrates that require coating processing is performed by repeating the operation from step 404 on the next coating substrate 8. The application operation (step 404 to step 408) is repeated until the application operation to the application substrate 8 is completed (step 407). In the middle of the application operation, the ink-jet head 5 needs to be cleaned. When the coating operation for the number of coated substrates 8 has been completed (step 408), the coating material discharge port 22 and the peripheral edge of the inkjet head 5 are cleaned by the cleaning device 15 (step 402), removed from the head bracket 6 and shown in FIG. This ink jet is attached to the head bracket 37 in the inspection mechanism B shown in FIG. Repeat the inspection of each coating material discharge port 22 of the head 5. This inspection is mainly for determining whether or not these coating material discharge ports 22 are defective, and the inspection result is taken into the PC 20 (step 403). Here, when the coating material discharge ports 22 determined to be defective are equal to or greater than the above-described allowable defective discharge ports, the inkjet head 5 is replaced with another inkjet head 5 as being unusable, and the above-described step 401 is performed. The application operation is resumed.

  As a result of the inspection, if the inkjet head 5 that has been used so far can be used, the inkjet head 5 is attached to the coating mechanism A again, and the operation is restarted from step 404.

  Then, when the application operation of the prescribed number of application substrates 8 that require application processing is completed (step 407), the inkjet head 5 is removed from the head bracket 6 and is applied to the head bracket 37 in the inspection mechanism section B shown in FIG. The coating material discharge port 22 and its peripheral portion are cleaned by the attachment and cleaning device 33 (step 409), and the above-described inspection of each coating material discharge port 22 is performed (step 410). This inspection is also mainly for determining whether or not the inkjet head 5 is defective by detecting the number of defects of the coating material discharge ports 22. Although the inkjet head 5 determined to be defective is discarded as it is, the usable inkjet head 5 is mounted by the above-described head protection device (not shown), and the operation is thereby completed.

  FIG. 13 is a schematic view showing a second embodiment of the ink jet coating apparatus according to the present invention. Parts corresponding to those in FIG. 1 and FIG.

  The second embodiment is provided with a coating mechanism portion similar to the coating mechanism portion A shown in FIG. 1, but the tray 33 can also be mounted on the suction table 14 of the coating mechanism portion. .

  FIG. 13 shows a state in which the tray 33 is mounted on the suction table 14 and is fixed by suction. Here, in the second embodiment, the camera 30 is provided on the end surface of one side of the suction table 14, and the light source 31 is provided on the end surface of the other side opposite thereto, so as to face each other. Yes. The optical axis of the camera 30 and the light source of the light source 31 are on the same straight line, and a cleaning device 33 is attached to the end surface of the other side of the suction table 14. Therefore, when the tray 33 is mounted on the suction table 14, an inspection mechanism unit having the same configuration as the inspection mechanism unit B shown in FIG. 3A is formed. When the tray 33 is removed, a coating substrate can be mounted on the suction table 14, and a coating mechanism portion similar to the coating mechanism portion A shown in FIG.

  In this way, instead of providing the camera 30, the light source 31, and the cleaning device 33 on the suction table 14, the tray 33 may be provided so that the tray 33 on which these are provided can be attached to and detached from the suction table 14.

  The inspection operation of the inspection mechanism unit of the second embodiment is the same as the operation of the inspection mechanism unit shown in FIG. 3 shown in FIGS. Further, the application operation of the application mechanism section of the second embodiment is the same as the operation shown in FIG. However, in the inspection operation shown in FIG. 12, it is not necessary to remove the inkjet head 5 from the head bracket 6 in the cleaning of the inkjet head 5 in steps 402 and 409 and the inspection of the inkjet head 5 in steps 403 and 410. 6 can be applied to the coated substrate and can be cleaned and inspected.

  In addition, when an organic EL device was produced using the inkjet coating apparatus of the present invention and an optimum voltage was applied thereto, it was confirmed that high quality characteristics free from defective pixels and color unevenness were obtained.

  Further, the example in which the above embodiment is an organic EL device manufacturing apparatus has been described. However, the present invention is not limited to this, and the present invention is not limited to this. The application head having a plurality of nozzles is used to place the organic EL device in a predetermined region. It goes without saying that the present invention can be applied to any apparatus for applying a certain amount of coating material to obtain high-quality pixels.

1 is a perspective view showing a first embodiment of an inkjet coating apparatus according to the present invention. FIG. 2 is a plan view schematically showing a specific example of the bottom surface (ejection surface) of the inkjet head in FIG. 1. It is a figure which shows one specific example of the inkjet head test | inspection mechanism part used for embodiment shown in FIG. It is explanatory drawing of the visual field of the camera shown in FIG. It is a figure which shows one specific example of the coating substrate used by embodiment shown in FIG. 1, and the application | coating state of a coating material. FIG. 2 is a diagram illustrating a relationship between a flying angle of a droplet from an inkjet head in FIG. 1 and variations in landing positions. It is explanatory drawing about the outline | summary of the satellite in embodiment shown in FIG. 1, and the gap length H1 between a coating substrate and an inkjet head. It is a figure shown about the relationship between the amount of droplets and the applied voltage in the inkjet head in FIG. 4 is a flowchart showing a specific example of the overall operation of the inkjet head inspection mechanism shown in FIG. 3. 10 is a flowchart showing a specific example of step 103 in FIG. 9. 10 is a flowchart showing a specific example of step 109 in FIG. 9. It is a flowchart which shows a specific example of the application | coating operation | movement of embodiment shown in FIG. It is a perspective view which shows 2nd Embodiment of the inkjet coating apparatus by this invention.

Explanation of symbols

A coating mechanism section 1 mount 2 frame 3 Z-axis stage 4 Z-axis drive motor 5 inkjet head 5a coating material discharge surface 6 head bracket 7 head drive substrate 8 coating substrate 9 X-axis stage 10 X-axis drive motor 11 Y-axis stage 12 Y Axis drive motor 13 θ direction rotation unit 14 Suction stage 15 Cleaning device 19 Monitor 20 PC
22 Application Material Discharge Port 23 Discharge Port Line B Inkjet Head Inspection Mechanism Unit 25 Y-axis Stage 26 Y-axis Drive Motor 27 X-axis Stage 28 X-axis Drive Motor 29 θ Direction Rotation Unit 30 Camera 30a Field of View 31 Light Source 32 Tray 33 Cleaning Device 34 Optical axis 35 Z-axis stage 36 Z-axis drive motor 37 Head bracket 38 Head drive substrate 39 Light source control device 40 Liquid droplet 41 Bank 42 Coating material 43 Ideal locus 44 Actual locus 45, 46 Drop landing point 47 Satellite 48, 49 Discharge characteristic straight line

Claims (6)

An application mechanism that discharges a coating material from a discharge port of an inkjet head and applies it to a substrate, and an inspection mechanism that inspects the inkjet head used in the application mechanism;
The inspection mechanism section
Detecting means for detecting a state of the droplet of the coating material discharged from the discharge port of the inkjet head;
An ink jet coating apparatus comprising: a voltage determining unit that determines an optimum applied voltage to the discharge port of the ink jet head based on a detection result of the detecting unit. In an ink jet coating apparatus that discharges a coating material from a discharge port of an ink jet head to apply to a substrate or the like,
Detecting means for detecting a state of the droplet of the coating material discharged from the discharge port of the inkjet head;
A voltage determining unit that determines an optimum applied voltage to the discharge port of the inkjet head based on a detection result of the detecting unit, and an inspection of the inkjet head used for applying the coating material to the substrate or the like An ink jet coating apparatus characterized in that The inkjet coating apparatus according to claim 1 or 2,
The ink jet coating apparatus, wherein the detecting means detects the presence or absence of ejection of the droplet, the droplet amount of the droplet, and the flying direction of the droplet. The inkjet coating apparatus according to claim 3.
Determination means for determining the performance state of the inkjet head from the detection result of the presence or absence of ejection of the droplet;
An ink jet coating apparatus comprising: a warning unit for replacing the ink jet head in accordance with a determination result of the determination unit. The inkjet coating apparatus according to claim 1 or 2,
The voltage determining means obtains a minimum applied voltage that can be ejected as droplets and a maximum applied voltage that does not generate satellites based on the detection result of the detecting means, and between the minimum applied voltage and the maximum applied voltage. An inkjet coating apparatus that determines the optimum applied voltage. The inkjet coating apparatus according to claim 1 or 2,
The ink jet coating apparatus, wherein the voltage determining means determines a swing voltage that is a maximum applied voltage at which droplets cannot be ejected based on a detection result of the detecting means.

Images