JP2008307523A - Coating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating device which can start the discharge of a coating liquid from a nozzle quickly and satisfactorily without increasing the consumption amount of the coating liquid, and causes no solvent shock problem. <P>SOLUTION: The coating device 1 first discharges only a main solvent from a nozzle 31, and then a ratio of an organic EL liquid is gradually increased and at the same time a ratio of the main solvent is gradually decreased. Finally, only the organic EL liquid is discharged from the nozzle 31. Thereby, the organic EL liquid can be discharged after discharging foreign matters and air bubbles staying inside of the nozzle 31 to the outside of the nozzle 31 together with the main solvent. As the replacement from main solvent to the organic EL liquid is gradually carried out, the solvent shock problem does not occur. As the discharge of the organic EL liquid can be started without repeating washing of the nozzle 31 and discharge of the organic EL liquid, the discharge of the organic EL liquid can be started quickly without increasing the consumption amount of the organic EL liquid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating apparatus for coating a coating liquid on the surface of various substrates such as a glass substrate for an organic EL display device, a glass substrate for a liquid crystal display device, a glass substrate for a PDP, a semiconductor wafer, a glass / ceramic substrate for a magnetic / optical disk. About.

  In the substrate manufacturing process, a coating apparatus that applies various coating solutions to the upper surface of the substrate is used. For example, in the manufacturing process of an organic EL display device, a coating device that applies an organic EL liquid to the upper surface of a glass substrate for the organic EL display device is used. As disclosed in, for example, Patent Documents 1 and 2, a conventional coating apparatus includes a nozzle for discharging a coating liquid toward the upper surface of a substrate, and a moving mechanism for relatively moving the nozzle and the substrate. And. The coating apparatus discharges the coating liquid in the form of a liquid column from the pores formed in the nozzle, and moves the nozzle and the substrate relatively while continuing to discharge such a coating liquid, so that the chemical liquid is applied to the upper surface of the substrate. Apply.

JP 2006-192435 A Japanese Patent No. 3676263

  In the coating apparatus as described above, when the discharge of the coating liquid from the nozzle is started, if foreign matter or bubbles stay in the nozzle or in the discharge hole, the coating liquid may not be discharged well from the nozzle. It was. In particular, when a highly viscous coating liquid such as an organic EL liquid is ejected from a fine ejection hole, foreign matter and bubbles inside the nozzle are likely to cause clogging of the coating liquid, and due to the surface tension of the coating liquid. Since the coating liquid easily diffuses around the discharge holes, it is difficult to form a good liquid column of the coating liquid below the nozzle.

  In addition, when the discharge of the coating liquid from the nozzle starts steeply, a so-called “solvent shock” is likely to occur, in which the shape of the liquid column of the coating liquid collapses below the nozzle. When a nozzle having a diameter of 70 μm or less was used, it was extremely difficult to form a good liquid column below the nozzle.

  Conventionally, when the discharge of the coating liquid from the nozzle is started, the cleaning of the nozzle and the discharge of the coating liquid from the nozzle are repeated, thereby realizing a state in which the coating liquid is favorably discharged from the nozzle. However, in such a method, it takes a long time until the coating liquid is discharged well, and the consumption of the coating liquid is also increased.

  The present invention has been made in view of such circumstances, and can quickly and satisfactorily start discharging the coating liquid from the nozzle without increasing the consumption of the coating liquid, and also causes a problem of solvent shock. An object of the present invention is to provide a coating apparatus that does not.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a coating apparatus that applies a coating liquid containing a substance to be coated and a predetermined organic solvent to the surface of the substrate, and discharges the coating liquid toward the surface of the substrate. A nozzle that is connected to the nozzle, a coating solution supply unit that supplies the coating solution to the piping unit, a solvent supply unit that supplies the organic solvent to the piping unit, and the coating solution supply unit And control means for controlling the solvent supply means, wherein the control means supplies the organic solvent from the solvent supply means in a state where supply of the coating liquid from the coating liquid supply means is stopped. After the solvent supply operation and the solvent supply operation, the supply amount of the organic solvent from the solvent supply means is gradually decreased and the supply amount of the coating liquid from the coating liquid supply means is gradually increased. Replace motion If, after said replacement operation, and the coating liquid supply operation for supplying the coating liquid from the coating liquid supplying means, characterized in that to execute.

  According to a second aspect of the present invention, in the coating apparatus according to the first aspect, in the replacement operation, the control means supplies the organic solvent from the solvent supply means and the coating liquid supply means in the replacement operation. The supply of the organic solvent from the organic solvent supply means is stopped when the supply amount of the coating liquid becomes substantially equal.

  According to a third aspect of the present invention, in the coating apparatus according to the first or second aspect, the coating liquid supply means includes a coating liquid piping and a coating liquid mass flow controller provided on the coating liquid piping. The solvent supply means includes a solvent pipe and a solvent mass flow controller provided on the solvent pipe, and the control means includes the coating liquid mass flow controller and the solvent mass flow controller. The replacement operation is executed by controlling.

  According to a fourth aspect of the present invention, in the coating apparatus according to any one of the first to third aspects, the coating liquid includes an organic EL material as the material to be coated.

  According to a fifth aspect of the present invention, in the coating apparatus according to any one of the first to fourth aspects, the nozzle discharges the coating liquid through a discharge hole having a diameter of 70 μm or less. And

  According to a sixth aspect of the present invention, there is provided a coating apparatus for applying a coating liquid containing a substance to be coated and a predetermined organic solvent on a surface of a substrate, and a nozzle for discharging the coating liquid toward the surface of the substrate; A connected piping section, a coating liquid supply means for supplying the coating liquid to the piping section, a solvent supply means for supplying the organic solvent to the piping section, the coating liquid supply means, and the solvent supply means. Control means for controlling, and the control means supplies a small amount of the coating liquid from the coating liquid supply means and a mixed liquid supply operation for supplying the organic solvent from the solvent supply means, After the mixed liquid supply operation, a replacement operation that gradually decreases the supply amount of the organic solvent from the solvent supply means and gradually increases the supply amount of the coating liquid from the coating liquid supply means, and the replacement After operation, before A coating liquid supply operation and for supplying the coating liquid from the coating liquid supply means and be executed.

  According to the first to fifth aspects of the invention, the coating apparatus includes a solvent supply operation for supplying the organic solvent from the solvent supply unit in a state where supply of the coating solution from the coating solution supply unit is stopped, and a solvent After the supply operation, the replacement operation of gradually decreasing the supply amount of the organic solvent from the solvent supply means and gradually increasing the supply amount of the coating solution from the coating solution supply means, and the coating solution supply means after the replacement operation The coating liquid supply operation for supplying the coating liquid from is performed. For this reason, it is possible to discharge the coating liquid from the nozzle after discharging foreign matter and bubbles staying inside the nozzle together with the solvent to the outside of the nozzle. In addition, since the liquid discharged from the nozzle is gradually replaced with the coating liquid from the organic solvent, the shape of the discharged liquid column collapses due to a sudden change in the concentration or viscosity of the liquid discharged from the nozzle. The occurrence of “shock” can be prevented. Therefore, the discharge of the coating liquid can be started favorably from the nozzle. Further, since the discharge of the coating liquid can be started without repeating the cleaning of the nozzle and the discharge of the coating liquid, the discharge of the coating liquid can be started quickly without increasing the consumption of the coating liquid. it can.

  In particular, according to the invention described in claim 2, in the coating operation, in the replacement operation, the supply amount of the organic solvent from the solvent supply unit and the supply amount of the coating solution from the coating solution supply unit become substantially equal. At the time, the supply of the organic solvent from the organic solvent supply means is stopped. For this reason, it can prevent that a coating liquid approachs into the solvent supply means side.

  In particular, according to the third aspect of the present invention, the supply amount of the coating liquid from the coating liquid supply unit and the supply amount of the solvent from the solvent supply unit are controlled using the mass flow controller. For this reason, the supply amounts of the coating liquid and the solvent can be easily and accurately controlled.

  In particular, according to the invention described in claim 4, a highly viscous coating liquid containing an organic EL material can be appropriately discharged from a nozzle.

  In particular, according to the invention described in claim 5, the nozzle discharges the coating liquid through the discharge hole having a diameter of 70 μm or less. In a nozzle having such a small-diameter discharge hole, it is particularly difficult to form a discharge liquid column of a coating liquid satisfactorily. However, according to the present invention, the discharge liquid column can be formed well. .

  According to the invention described in claim 6, the coating apparatus includes a mixed liquid supply operation for supplying a small amount of coating liquid from the coating liquid supply means, and supplying an organic solvent from the solvent supply means, and mixing. After the liquid supply operation, a replacement operation in which the supply amount of the organic solvent from the solvent supply means is gradually decreased and the supply amount of the coating liquid from the coating liquid supply means is gradually increased. The coating liquid supply operation for supplying the coating liquid from the means is executed. For this reason, it is possible to discharge the coating liquid from the nozzle after discharging foreign matter and bubbles staying inside the nozzle together with the solvent to the outside of the nozzle. In addition, since the liquid discharged from the nozzle is gradually replaced with the coating liquid from the organic solvent, the shape of the discharged liquid column collapses due to a sudden change in the concentration or viscosity of the liquid discharged from the nozzle. The occurrence of “shock” can be prevented. Accordingly, the discharge of the coating liquid can be favorably started from the nozzle. In addition, since the discharge of the coating liquid can be started without repeating the cleaning of the nozzle and the discharge of the coating liquid, the discharge of the coating liquid can be started quickly without increasing the consumption of the coating liquid. it can.

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

<1. Configuration of coating device>
FIG. 1 is a top view showing a configuration of a coating apparatus 1 according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the coating apparatus 1 taken along the line II-II in FIG. Each of these drawings is provided with a common XYZ orthogonal coordinate system in order to clarify the positional relationship and operation direction of each part in the apparatus.

  The coating apparatus 1 shown in FIGS. 1 and 2 includes an organic EL material (a material to be coated) and an upper surface of a rectangular glass substrate (hereinafter simply referred to as “substrate”) 9 in a process of manufacturing an organic EL display device. It is an apparatus for applying an organic EL liquid mixed with a predetermined solvent. As shown in FIGS. 1 and 2, the coating apparatus 1 mainly controls the stage 10, the stage moving mechanism 20, the nozzle unit 30, the nozzle moving mechanism 40, the standby pod 50, the collection tray 60, and the control. Part 70.

  The stage 10 has a flat outer shape, and is a holding unit for placing and holding the substrate 9 on the upper surface thereof in a horizontal posture. A plurality of suction holes (not shown) are formed on the upper surface of the stage 10. For this reason, when the substrate 9 is placed on the stage 10, the substrate 9 is fixedly held on the upper surface of the stage 10 by the suction pressure of the suction holes. On the upper surface of the substrate 9 placed on the stage 10, a number of parallel grooves 9a are formed in advance at positions where the organic EL liquid is applied. The substrate 9 is placed on the stage 10 so that these grooves 9a face the main scanning direction (X-axis direction).

  Also, above the stage 10, mask plates 11 and 12 that cover the −X side and + X side sides of the substrate 9 are arranged. The mask plates 11 and 12 prevent the organic EL liquid discharged from the nozzle unit 30 described later from being applied to the + X side and −X side sides of the substrate 9, and the organic EL liquid in the main scanning direction. It plays a role in defining the application range. The mask plates 11 and 12 are fixedly attached to the stage 10 via a predetermined connection member (not shown).

  The stage moving mechanism 20 is a mechanism for moving the stage 10 in the sub-scanning direction (Y-axis direction). The stage moving mechanism 20 is configured by, for example, a mechanism that combines a motor and a ball screw, or a mechanism that uses a linear motor. When the stage moving mechanism 20 is operated with the substrate 9 placed on the stage 10, the stage 10, the mask plates 11 and 12, and the substrate 9 move together in the sub-scanning direction.

  The nozzle unit 30 is a discharge unit for discharging the organic EL liquid toward the upper surface of the substrate 9 held on the stage 10. The nozzle unit 30 has three nozzles 31 for discharging red, green, and blue organic EL liquids. As shown in FIG. 1, the three nozzles 31 are arranged at a predetermined interval (for example, a pitch of several mm) in the main scanning direction, and the positions in the sub-scanning direction are also slightly shifted. The difference in position of each nozzle 31 in the sub-scanning direction corresponds to the pitch width of the grooves 9a formed on the upper surface of the substrate 9 to be processed. Therefore, the nozzle unit 30 can simultaneously discharge the organic EL liquid to the three adjacent grooves 9 a on the substrate 9 by discharging the organic EL liquid from the three nozzles 31 at the same time.

  As described above, the coating apparatus 1 can apply the organic EL liquid on the substrate 9 in three rows using the three nozzles 31. For this reason, the organic EL liquid can be efficiently applied to the upper surface of the substrate 9. In addition, since the positions of the three nozzles 31 in the main scanning direction and the sub-scanning direction are all different, the organic EL liquid can be applied at a narrow interval without extremely miniaturizing each nozzle 31 itself. Can do.

  FIG. 3 is a diagram illustrating one of the three nozzles 31 included in the nozzle unit 30 and the configuration of the liquid feeding system 80 connected to the nozzle 31. As shown in FIG. 3, the nozzle 31 has a nozzle body 31a and a small discharge hole 31b (for example, a hole diameter of 10 μm or more and 70 μm or less) formed at the lower end of the nozzle body 31a. . In addition, a liquid feed path (not shown) communicating with the discharge hole 31b and a main pipe 81 described later is formed inside the nozzle 31.

  One main pipe 81 is connected to the nozzle 31. The main pipe 81 is connected to an organic EL liquid supply pipe 83 and a main solvent supply pipe 84 via a T-shaped mixing portion 82. An organic EL liquid supply source 85 that supplies an organic EL liquid in which an organic EL material and a solvent are mixed at a predetermined ratio is connected to an upstream end of the organic EL liquid supply pipe 83. In addition, a mass flow controller 83a and an opening / closing valve 83b are interposed in the path of the organic EL liquid supply pipe 83. On the other hand, a main solvent supply source 86 that supplies a main solvent that is one of the solvent components of the organic EL liquid is connected to an upstream end of the main solvent supply pipe 84. A mass flow controller 84a and an on-off valve 84b are interposed in the middle of the route of the main solvent supply pipe 84. As the main solvent supplied from the main solvent supply source 86, for example, mesitylene, anisole or the like having high volatility at room temperature can be used.

  In such a liquid feeding system 80, when the on-off valve 83 b is opened, the organic EL liquid is supplied from the organic EL liquid supply source 85 to the main pipe 81 through the organic EL liquid supply pipe 83 and the mixing unit 82. Further, when the mass flow controller 83a is controlled while opening the on-off valve 83b, the supply amount per unit time of the organic EL liquid supplied from the organic EL liquid supply source 85 to the main pipe 81 is controlled.

  On the other hand, in the liquid feeding system 80, when the on-off valve 84 b is opened, the main solvent is supplied from the main solvent supply source 86 to the main pipe 81 through the main solvent supply pipe 84 and the mixing unit 82. Further, when the mass flow controller 84a is controlled while opening the on-off valve 84b, the supply amount of the main solvent supplied from the main solvent supply source 86 to the main pipe 81 per unit time is controlled.

  That is, the liquid feeding system 80 of this embodiment has a supply system for supplying the organic EL liquid to the main pipe 81 and a supply system for supplying the main solvent to the main pipe 81, and the on-off valve 83b, By controlling the open / close state of 84b, the organic EL liquid and the main solvent can be selectively or simultaneously supplied from these supply systems to the main pipe 81. Further, the liquid feeding system 80 of the present embodiment controls the mass flow controllers 83a and 84a in a state where both the on-off valves 83b and 84b are opened, thereby adjusting the ratio between the organic EL liquid and the main solvent. The mixed liquid can be supplied to the main pipe 81.

  The organic EL liquid, the main solvent, or a mixed solution thereof supplied to the main pipe 81 is introduced from the main pipe 81 to the liquid feed path inside the nozzle 31 and is directed downward from the discharge hole 31b at the lower end of the nozzle 31. Discharged. When the discharge of the organic EL liquid is started by a discharge start operation to be described later, the organic EL liquid discharged from the discharge hole 31 b of the nozzle 31 forms a liquid column L below the nozzle 31. Although one nozzle 31 and its liquid feeding system 80 have been described in FIG. 3, an equivalent liquid feeding system 80 is also connected to the other nozzles 31 included in the nozzle unit 30.

  Returning to FIG. 1 and FIG. 2, the description of the coating apparatus 1 is continued.

  The nozzle moving mechanism 40 is a mechanism for moving the nozzle unit 30 in the main scanning direction. As illustrated in FIG. 1, the nozzle moving mechanism 40 includes a support portion 41 for supporting the nozzle portion 30 and a moving portion 42 for moving the support portion 41 in the main scanning direction. The moving unit 42 is configured by, for example, a mechanism that combines a motor and a ball screw, or a mechanism that uses a linear motor. The nozzle moving mechanism 40 moves the nozzle unit 30 in the main scanning direction between any position between the upper position of the standby pod 50 and the upper position of the collection tray 60 arranged on the + X side of the stage 10. be able to.

  The standby pod 50 is a part for waiting the nozzle unit 30 on the side of the stage 10 on the −X side. On the standby pod 50, three openings 51 for accommodating the lower end portions of the nozzles 31 of the nozzle portion 30 are formed. When the nozzle unit 30 is put on standby, the nozzle unit 30 is placed above the standby pod 50 and the standby pod 50 is moved up to accommodate the lower end of each nozzle 31 in each opening 51. Inside the standby pod 50, there is provided a recovery mechanism for recovering the organic EL liquid, the main solvent, or a mixture thereof discharged from each nozzle 31 during standby.

  The collection tray 60 is a container for collecting the organic EL liquid discharged from the nozzle unit 30 on the + X side and the −X side of the stage 10. The collection tray 60 is disposed at a position below the moving path of the nozzle unit 30 on the −X side of the stage 10 (between the stage 10 and the standby pod 50) and the + X side of the stage 10. The collection tray 60 is arranged so as to partially overlap the mask plates 11 and 12 in the main scanning direction. For this reason, the organic EL liquid discharged from the nozzle unit 30 on the side of the stage 10 is continuously collected by the mask plates 11 and 12 and the collection tray 60.

  The control unit 70 is a processing unit for controlling the operation of each unit in the coating apparatus 1. FIG. 4 is a block diagram illustrating a connection configuration between the control unit 70 and each unit in the coating apparatus 1. As shown in FIG. 4, the control unit 70 is electrically connected to the stage moving mechanism 20, the nozzle moving mechanism 40, the standby pod 50, the mass flow controllers 83a and 84a, and the on-off valves 83b and 84b. These operations are controlled. The control unit 70 is configured by a computer having, for example, a CPU and a memory, and controls the operation of each unit as the computer operates in accordance with a program installed in the computer and an operation input from the user.

<2. Operation of coating apparatus>
<2-1. Operation at the start of discharge>
Next, the operation when starting the discharge of the organic EL liquid in the coating apparatus 1 will be described with reference to the flowchart of FIG. 5 and the graph of FIG. In the graph of FIG. 6, the broken line with □ indicates the flow rate of the organic EL liquid supplied from the organic EL liquid supply source 85 to the main pipe 81 via the organic EL liquid pipe 83, and the broken line with ○ is The flow rate of the main solvent supplied from the main solvent supply source 86 to the main pipe 81 via the main solvent supply pipe 84 is shown. The operation described below is a state in which each nozzle 31 of the nozzle unit 30 is housed in each opening 51 of the standby pod 50 when the discharge of the organic EL liquid is started, for example, after the coating apparatus 1 is started. This operation is performed for each nozzle 31. In the following discharge start operation, the mass flow controllers 83 a and 84 a and the on-off valves 83 b and 84 b operate according to the command from the control unit 70.

  When discharging the organic EL liquid in the coating apparatus 1, first, the on-off valve 84b is opened while the on-off valve 83b is closed. Thereby, the main solvent is supplied from the main solvent supply source 86 to the nozzle 31 through the main solvent supply pipe 84, the mixing unit 82, and the main pipe 81, and the main solvent is directed downward from the discharge hole 31 b of the nozzle 31. Discharge is performed (FIG. 5: Step S1, FIG. 6: Time t1 to t2). At this time, the mass flow controller 84a is preset to a predetermined opening, and the main solvent having a flow rate Fa corresponding to the opening is supplied.

  Since the main solvent supplied from the main solvent supply source 86 does not contain an organic EL material, the viscosity as a liquid is low. For this reason, the main solvent is smoothly discharged from the discharge hole 31 b of the nozzle 31, and forms a liquid column L below the nozzle 31. In addition, due to the main solvent being discharged, foreign substances and bubbles remaining in the liquid delivery path inside the discharge hole 31b and the nozzle 31 are discharged to the outside of the nozzle 31 together with the main solvent, and these substances that become discharge resistance are excluded. Is done.

  Next, the coating apparatus 1 opens the on-off valve 83b in a state where the set flow rate of the mass flow controller 83a is minimized. Then, while gradually decreasing the set flow rate of the mass flow controller 84a and gradually increasing the set flow rate of the mass flow controller 83a, the proportion of the organic EL liquid in the mixed liquid supplied to the main pipe 81 is gradually increased. . That is, the amount of the main solvent supplied from the main solvent supply source 86 is gradually reduced, and the amount of the organic EL solution supplied from the organic EL solution supply source 85 is gradually increased (FIG. 5: Step S2). , FIG. 6: times t2 to t3). Thereby, the density | concentration of the organic EL material in the liquid mixture discharged from the nozzle 31 rises gradually, and the viscosity of a liquid mixture also becomes high gradually.

  In step S2 of the present embodiment, the amount of decrease in the flow rate of the main solvent supplied from the main solvent supply source 86 is always equal to the amount of increase in the flow rate of the organic EL solution supplied from the organic EL solution supply source 85. The mass flow controllers 83a and 84a are controlled so that the total flow rate is always maintained at Fa. For this reason, the flow rate of the main solvent supplied from the main solvent supply source 86 and the flow rate of the organic EL solution supplied from the organic EL solution supply source 85 eventually become Fa / 2 at time t3. Thus, by maintaining the total flow rate of the main solvent and the organic EL liquid supplied to the main pipe 81 at a constant value Fa, the fluid flow pressure in the main pipe 81 is maintained uniformly. Therefore, the organic EL material does not locally precipitate in the liquid in the main pipe 81.

  At times t2 to t3 in FIG. 6, the supply amount of the main solvent and the supply amount of the organic EL liquid are continuously changed (that is, the set flow rates of the mass flow controllers 83a and 84a are continuously changed). However, the supply amount of the main solvent and the supply amount of the organic EL liquid may be changed stepwise.

  When the flow rate of the main solvent supplied from the main solvent supply source 86 and the flow rate of the organic EL solution supplied from the organic EL solution supply source 85 are both Fa / 2 at time t3, the coating apparatus 1 The supply of the main solvent is stopped by closing 84b, and the set flow rate of the mass flow controller 83a is increased to Fa at once (FIG. 5: step S3, FIG. 6: time t3). As a result, only the organic EL liquid having a flow rate Fa supplied from the organic EL liquid supply source 85 flows through the main pipe 81.

  In step S3 of the present embodiment, when the flow rate of the main solvent supplied from the main solvent supply source 86 and the flow rate of the organic EL solution supplied from the organic EL solution supply source 85 are substantially equal in this way. The supply of the main solvent is stopped and the flow rate of the organic EL liquid is increased at a stretch. This is because when the flow pressure on the main solvent side becomes smaller than the flow pressure on the organic EL liquid side in a state where both the on-off valves 83b and 84b are opened, the organic EL liquid supplied from the organic EL liquid pipe 83 becomes the main solvent pipe. This is to prevent such an organic EL liquid from entering since there is a risk of entering into 84.

  Further, in step S3 of the present embodiment, the flow rate of the organic EL liquid is increased to Fa at the same time as the supply of the main solvent is stopped, so that the flow pressure of the liquid supplied to the main pipe 81 is kept constant. This is for preventing the precipitation of the organic EL material.

  After that, the coating apparatus 1 gradually decreases the set flow rate of the mass flow controller 83a from Fa to the final target value Fb (FIG. 5: Step S4, FIG. 6: Time t4 to t5). For example, if the above-mentioned step S2 (t2 to t3) takes about 5 minutes, then in this step S4 (t4 to t5), it takes about 10 minutes, which is twice that time. Reduce the flow rate. Thus, by drastically reducing the flow rate of the organic EL liquid over time, it is possible to prevent sudden fluctuations in the flow pressure in the main pipe 81.

  With the above operation, the organic EL liquid is discharged from the discharge hole 31b of the nozzle 31 while forming the liquid column L having a good shape.

  Thus, the coating apparatus 1 of the present embodiment first discharges only the main solvent from the nozzle 31, and then gradually increases the proportion of the organic EL liquid and gradually decreases the proportion of the main solvent. Thus, only the organic EL liquid is discharged from the nozzle 31. For this reason, it is possible to discharge the organic EL liquid after discharging the foreign matters and bubbles staying in the nozzle 31 to the outside of the nozzle 31 together with the main solvent. Accordingly, the discharge of the organic EL liquid can be favorably started from the nozzle 31. Moreover, since the discharge of the organic EL liquid can be started without repeating the cleaning of the nozzle 31 and the discharge of the organic EL liquid, the organic EL liquid can be discharged quickly without increasing the consumption of the organic EL liquid. Can be started.

  In particular, the coating apparatus 1 according to the present embodiment switches between supply of the main solvent and supply of the organic EL liquid to the nozzle 31 by opening and closing the on-off valves 83b and 84b without switching the pipe connected to the nozzle 31. . For this reason, it can prevent that a new foreign material and a bubble mix in the inside of the nozzle 31. FIG.

  In addition, the coating apparatus 1 of the present embodiment gradually decreases the supply amount of the main solvent from the main solvent supply source 86 and gradually increases the supply amount of the organic EL solution from the organic EL solution supply source 85. The liquid discharged from the nozzle 31 is gradually replaced from the main solvent to the organic EL liquid. For this reason, it is possible to prevent the so-called “solvent shock” in which the shape of the discharge liquid column L collapses due to a sudden change in the concentration or viscosity of the liquid discharged from the nozzle. In addition, since the concentration of the organic EL material is gradually changed, problems such as gelation of the organic EL liquid due to a rapid change in the concentration do not occur even when the organic EL material is composed of a low molecular compound.

<2-2. Application processing operation>
Next, the operation when applying the organic EL liquid on the upper surface of the substrate 9 in the coating apparatus 1 will be described with reference to the flowchart of FIG. In addition, at the time of starting the coating process described below, the above 2-1. The discharge start operation of the organic EL liquid described in the above has already been completed, and the organic EL liquid is well discharged in a liquid column shape from each nozzle 31 of the nozzle unit 30 in the standby pod 50.

  When performing the coating process of the substrate 9 in the coating apparatus 1, first, the substrate 9 is placed on the upper surface of the stage 10 (step S5). The substrate 9 is placed on the stage 10 so that the plurality of grooves 9a formed on the upper surface thereof face the main scanning direction. In addition, the stage moving mechanism 20 moves the stage 10 and adjusts the position of the substrate 9 so that the three + Y side grooves 9 a on the substrate 9 are positioned below the scanning area of the nozzle unit 30.

  Next, the coating apparatus 1 moves the nozzle unit 30 to the + X side by lowering the standby pod 50 and pulling the standby pod 50 away from the nozzle 31 and operating the nozzle moving mechanism 40. The nozzle unit 30 moves to the + X side while discharging the organic EL liquid from each nozzle 31, and applies the organic EL liquid on the three grooves 9 a on the most + Y side on the substrate 9. A part of the organic EL liquid discharged during the movement of the nozzle unit 30 falls on the upper surface of the collection tray 60 and the mask plates 11 and 12 and is collected.

  When the nozzle unit 30 moves to the upper part of the mask plate 12 on the + X side, the coating apparatus 1 then operates the stage moving mechanism 20 to apply the coating width of the three nozzles 31 (that is, three rows of grooves 9a). Move the stage 10 to the + Y side. Then, the nozzle unit 30 is moved to the −X side while continuing to discharge the organic EL liquid from the nozzle 31. As a result, the organic EL is applied to the next three grooves 9 a on the substrate 9.

  As described above, the coating apparatus 1 repeats the application of the organic EL liquid in the main scanning direction a predetermined number of times while shifting the substrate 9 in the sub-scanning direction by the coating width of the nozzle unit 30, and all the grooves 9 a on the substrate 9. An organic EL solution is applied on the top (step S6).

  When the organic EL liquid is applied to all the grooves 9 a on the substrate 9, the coating apparatus 1 further operates the nozzle moving mechanism 40 to move the nozzle unit 30 to a position above the standby pod 50. When the nozzle unit 30 moves to an upper position of the standby pod 50, the coating apparatus 1 stores the lower end of each nozzle 31 in each opening 51 of the standby pod 50 by raising the standby pod 50. And the board | substrate 9 after an application | coating process is carried out from the stage 10 (step S7), and the application | coating process of the organic EL liquid with respect to the one board | substrate 9 is complete | finished.

<3. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to said example. For example, in the above example, the three nozzles 31 are mounted on the nozzle unit 30 of the coating apparatus 1, but the number of nozzles mounted on the nozzle unit 30 may be one or two. It may be more than this. In addition, the coating apparatus 1 includes three nozzles 31 for discharging red, green, and blue organic EL liquids. However, the coating apparatus of the present invention includes a plurality of nozzles 31. A monochromatic organic EL liquid may be discharged.

  In the above example, the mass flow controllers 83a and 84a are used to adjust the supply amounts of the organic EL liquid and the main solvent, but other flow rate adjusting mechanisms are used to adjust the organic EL liquid and the main solvent. The supply amount may be adjusted. For example, as an alternative to the mass flow controllers 83a and 84a, a flow control valve without a flow sensor may be used.

  In step S2 of the discharge start operation, the flow rate of the main solvent is decreased linearly (with a constant change rate), and the flow rate of the organic E solution is increased linearly (with a constant change rate). The flow rate changes of the main solvent and the organic EL liquid need not be such linear changes (changes with a constant change rate). For example, as shown in FIG. 8, the flow rate of the main solvent is decreased so that the rate of change gradually decreases (so that the absolute value of the rate of change gradually increases), and the flow rate of the organic EL liquid is The rate of change may be increased so as to increase gradually. In this way, a rapid concentration change can be prevented at time t2 when the supply of the organic EL liquid is started.

  In step S1 of the discharge start operation, the supply of the main solvent is started in a state where the supply of the organic EL liquid is stopped. However, a small amount of the organic EL liquid may be supplied from the beginning. That is, first, a mixed liquid containing a small amount of organic EL liquid and a large amount of main solvent is discharged from the nozzle 31, and thereafter the ratio of the organic EL liquid is gradually increased and the ratio of the main solvent is gradually decreased. For example, only the organic EL liquid may be discharged from the nozzle 31.

  Moreover, although the said coating apparatus 1 apply | coated the organic EL liquid containing the organic EL material as a to-be-coated material on the upper surface of the board | substrate 9, the coating apparatus of this invention is an antireflection film material and photoresist. A coating solution containing another material to be coated such as a material may be applied to the upper surface of the substrate 9. In addition, the coating apparatus of the present invention may apply a coating solution obtained by mixing an aqueous material to be coated and an aqueous solvent to the upper surface of the substrate 9. In addition, the coating apparatus 1 described above is targeted for processing the glass substrate 9 for an organic EL display device, but the coating apparatus of the present invention is for a glass substrate for a liquid crystal display device, a glass substrate for a PDP, a semiconductor wafer, and a magnetic / optical disk. Other substrates such as glass / ceramic substrates may be used as a processing target.

It is a top view of the coating device concerning one embodiment of the present invention. It is the longitudinal cross-sectional view which cut | disconnected the coating device by the II-II line | wire of FIG. It is the figure which showed the structure of a nozzle and a liquid feeding system. It is the block diagram which showed the connection structure of each part in a coating device, and a control part. It is the flowchart which showed the flow of operation | movement when starting discharge of organic EL liquid. It is the graph which showed the fluctuation | variation of the supply amount of organic EL liquid and a main solvent. It is the flowchart which showed the flow of operation | movement when apply | coating organic EL liquid on the upper surface of a board | substrate. It is the graph which showed the fluctuation | variation of the supply amount of the organic electroluminescent liquid and main solvent which concern on a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating apparatus 9 Substrate 20 Stage moving mechanism 30 Nozzle part 31 Nozzle 31b Discharge hole 40 Nozzle moving mechanism 50 Standby pod 51 Opening part 60 Collection tray 70 Control part 80 Liquid supply system 81 Main piping 82 Mixing part 83 Pipe for organic EL liquid supply 83a Mass flow controller 83b On-off valve 84 Main solvent supply piping 84a Mass flow controller 84b On-off valve 85 Organic EL liquid supply source 86 Main solvent supply source L Liquid column

Claims (6)

In a coating apparatus that coats a coating liquid containing a substance to be coated and a predetermined organic solvent on the surface of a substrate,
A nozzle for discharging the coating liquid toward the surface of the substrate;
A pipe connected to the nozzle;
A coating solution supply means for supplying the coating solution to the pipe section;
A solvent supply means for supplying the organic solvent to the pipe part;
Control means for controlling the coating liquid supply means and the solvent supply means;
With
The control means includes
A solvent supply operation for supplying the organic solvent from the solvent supply means in a state where supply of the coating liquid from the coating liquid supply means is stopped;
After the solvent supply operation, a replacement operation that gradually decreases the supply amount of the organic solvent from the solvent supply unit and gradually increases the supply amount of the coating solution from the coating solution supply unit;
After the replacement operation, a coating liquid supply operation for supplying the coating liquid from the coating liquid supply means,
A coating apparatus characterized by being executed. The coating apparatus according to claim 1,
The control means includes
In the replacement operation, when the supply amount of the organic solvent from the solvent supply unit becomes substantially equal to the supply amount of the coating liquid from the coating solution supply unit, the organic solvent supply unit from the organic solvent supply unit A coating apparatus, wherein supply of the solvent is stopped. In the coating device according to claim 1 or 2,
The coating solution supply means includes a coating solution pipe and a coating solution mass flow controller provided on the coating solution pipe.
The solvent supply means includes a solvent pipe and a solvent mass flow controller provided on the solvent pipe.
The said control means performs the said replacement operation by controlling the said mass flow controller for coating liquids, and the said mass flow controller for solvents, The coating device characterized by the above-mentioned. In the coating device according to any one of claims 1 to 3,
The coating apparatus includes an organic EL material as the material to be coated. In the coating device according to any one of claims 1 to 4,
The said nozzle discharges the said coating liquid through the discharge hole which has a diameter of 70 micrometers or less, The coating device characterized by the above-mentioned. In a coating apparatus that applies a coating liquid containing a substance to be coated and a predetermined organic solvent to the surface of the substrate
A nozzle for discharging the coating liquid toward the surface of the substrate;
A pipe connected to the nozzle;
A coating solution supply means for supplying the coating solution to the pipe section;
A solvent supply means for supplying the organic solvent to the pipe part;
Control means for controlling the coating liquid supply means and the solvent supply means;
With
The control means includes
A mixed liquid supply operation for supplying a small amount of the coating liquid from the coating liquid supply means and supplying the organic solvent from the solvent supply means;
After the mixed liquid supply operation, a replacement operation that gradually decreases the supply amount of the organic solvent from the solvent supply means and gradually increases the supply amount of the coating liquid from the coating liquid supply means;
After the replacement operation, a coating liquid supply operation for supplying the coating liquid from the coating liquid supply means,
A coating apparatus characterized by being executed.

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