JP2012071268A - Coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the uniformity of the film thickness of an applied coating liquid.SOLUTION: The coating apparatus in which a discharge part which discharges a coating liquid is relatively moved to a substrate, and which thereby applies the coating liquid to the substrate and forms a coating film includes: a discharge part which discharges the coating liquid to the substrate; a moving mechanism which makes the discharge part relatively move to the substrate; an acquisition part which acquires the film thickness information of the coating film formed in a trial manner using the discharge part and the moving mechanism; and a speed change part. In addition, the speed change part changes the moving speed of the discharge part under the relative movement to the substrate based on the film thickness information.

Description

  The present invention includes a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a PDP (Plasma Display Panel), a glass substrate for an organic EL display panel, a substrate for photovoltaic power generation, a glass for glass of magnetism or optical disk or a ceramic substrate, The present invention relates to a coating technique for coating a coating liquid on various substrates to be treated such as a metal foil to which a battery electrode material is coated.

  In the manufacture of an organic EL display device using an organic EL (Electro Luminescence) material, a fluid material containing the organic EL material (hereinafter referred to as “organic EL liquid”) or the like is used as a glass substrate for the display device (hereinafter simply referred to as “organic EL liquid”). 2. Description of the Related Art A coating apparatus that applies stripes to grooves between a plurality of partition walls formed on a substrate is referred to as a “substrate”.

  Conventionally, the thing of patent document 1 is known as this kind of coating device.

  In Patent Document 1, an application head including a plurality of nozzles that continuously discharge organic EL liquid toward a substrate is moved in a main scanning direction along a groove between partition walls formed on the substrate, and Each time the coating head is moved in the main scanning direction, a moving mechanism that moves the substrate in the sub scanning direction with respect to the coating head, and a relative position in the sub scanning direction with respect to the coating head is fixed, and a plurality of nozzles are fixed. A coating apparatus is disclosed that includes a light irradiation unit that irradiates light to the organic EL liquid while the discharged organic EL liquid has fluidity to promote drying of the organic EL liquid.

  In the organic EL display device, in order to prevent luminance unevenness when the organic EL emits light, it is required to make the thickness of the organic EL layer formed on the substrate uniform after drying. In the coating apparatus described in 1., the uniformity of the film thickness after drying of the organic EL liquids of the plurality of lines is improved by improving the uniformity of the drying speed of the organic EL liquids of the plurality of lines applied to the substrate. Is planned.

JP 2009-123585 A

  In the coating apparatus of Patent Document 1, in order to improve the uniformity of the film thickness after drying the organic EL liquid applied on the substrate, it is necessary to improve the uniformity of the film thickness of the applied organic EL liquid. is there.

  Conventionally, in this type of coating apparatus, the coating head is continuously discharged in the main scanning direction at a constant speed while the coating liquid is continuously discharged from each of the discharge ports toward the upper surface of the substrate at a constant discharge flow rate. The film thickness of the applied coating solution was made uniform by moving in step (1).

  However, for example, even if control for making the discharge flow rate constant using an MFC (Mass Flow Controller) is attempted, volume variation in the scan tube due to bending of the scan tube as the coating head moves, coating liquid Since it is difficult to keep the discharge flow rate constant due to the inertial force applied to the film, there is a problem that it is difficult to improve the uniformity of the film thickness of the applied coating liquid.

  The present invention has been made to solve these problems, and an object of the present invention is to provide a technique capable of improving the uniformity of the film thickness of the applied coating solution.

  In order to solve the above-described problems, the invention of claim 1 is a coating that forms a coating film by applying a coating liquid to a substrate by moving a discharge unit that discharges the coating solution relative to the substrate. An apparatus, a discharge unit that discharges a coating liquid onto a substrate, a movement mechanism that moves the discharge unit relative to the substrate, and a coating that is formed on a trial basis using the discharge unit and the movement mechanism An acquisition unit that acquires film thickness information of a film, and a speed change unit that changes a moving speed of the discharge unit that is moving relative to the substrate according to the film thickness information.

  The invention of claim 2 is the coating apparatus according to claim 1, wherein there is a negative correlation between the moving speed of the discharge unit and the film thickness of the coating film, and the speed changing unit is , For the portion of the substrate where the film thickness information is thicker than a reference film thickness, the movement speed of the discharge section is made faster than the movement speed of the discharge section when the coating film is formed on a trial basis, For a portion of the substrate where the film thickness information is thinner than a reference film thickness, the movement speed of the ejection section is made slower than the movement speed of the ejection section when the coating film is formed on a trial basis. To do.

  Further, the invention of claim 3 is the coating apparatus according to claim 1 or claim 2, wherein the moving mechanism is configured so that the ejection unit is alternately arranged in a predetermined forward direction and a forward direction with respect to the substrate. Relatively moving main scanning is performed, the ejection unit ejects the coating liquid onto the substrate in the main scanning forward path and the backward path, and the speed changing unit moves the ejection section in the main scanning forward path. The speed distribution of the speed and the speed distribution of the moving speed of the ejection unit in the return path of the main scanning are set to be different from each other.

  The invention of claim 4 is the coating apparatus according to claim 1, wherein there is a positive correlation between the moving speed of the discharge unit and the film thickness of the coating film, and the speed changing unit is The movement speed of the discharge part is made slower than the movement speed of the discharge part when the coating film is formed on a trial basis for a portion of the substrate where the film thickness information is thicker than a reference film thickness, For a portion of the substrate where the film thickness information is thinner than a reference film thickness, the movement speed of the discharge section is made faster than the movement speed of the discharge section when the coating film is formed on a trial basis. To do.

  Further, the invention of claim 5 is a coating method in which a coating film is formed by coating a coating liquid on the substrate using a predetermined coating apparatus that moves a discharge section discharging the coating liquid relative to the substrate. According to the film thickness information, the acquisition step of acquiring the film thickness information of the coating film formed on a trial basis using the coating apparatus, and the moving speed of the discharge unit during relative movement with respect to the substrate And a speed changing step for changing.

  According to the first aspect of the present invention, the moving speed of the discharge portion that is moving relative to the substrate while discharging the coating liquid onto the substrate is determined according to the film thickness information of the coating film obtained from the previously formed coating film. Therefore, the uniformity of the coating film thickness can be improved.

It is a schematic plan view which shows the coating device which concerns on embodiment. It is a schematic front view which shows the coating device same as the above. It is a figure which shows one example of the relationship between the discharge flow volume of a coating liquid, and the film thickness of a coating film. It is a figure which shows one example of the film thickness distribution of the coating film formed in the board | substrate. It is a figure which shows one example of the relationship between the moving speed of the discharge part in 1 point, and a film thickness. It is a figure which shows another example of a relationship same as the above. It is a figure which shows one example of the relationship between the moving speed of a discharge part, and a film thickness fluctuation | variation. It is a figure which shows another example of a relationship same as the above. It is a figure which shows another example of a relationship same as the above. It is a figure which shows another example of a relationship same as the above. It is a figure explaining the operation | movement flow of the coating device which concerns on embodiment. It is a figure explaining the operation | movement flow of the coating device which concerns on embodiment.

<About the overall configuration:>
Hereinafter, the coating apparatus according to the embodiment will be described. FIG. 1 is a schematic plan view showing a coating apparatus 20 according to the embodiment, and FIG. 2 is a schematic front view showing the coating apparatus 20. For convenience of explanation, a direction along a main scanning direction, which will be described later, may be described as an X direction, a direction orthogonal to the X direction and the vertical direction may be referred to as a Y direction, and a vertical direction may be described as a Z direction. The coating device 20 is a device that applies a coating solution to the substrate 10. As the substrate 10, for example, a rectangular glass substrate for a flat display device, a metal foil to which an electrode material for a battery is applied, and the like are assumed. Further, as the coating liquid, a forming material such as a pattern to be formed on the substrate 10, for example, a liquid containing an organic EL material and a solvent thereof is assumed when an organic EL display device is manufactured. In addition, for example, when manufacturing a battery is assumed, as a coating solution, for example, a positive electrode active material such as a lithium transition metal composite oxide, a conductive material, a binder, and a thickener are added to a solvent and kneaded. Dispersed electrode-forming paints and the like are assumed.

  The coating apparatus 20 includes a substrate holding unit 30, a guide unit 40, a main scanning drive mechanism 44, a movable coating unit 50, a counter guide unit 70, a counter slider 74, and piping members 80, 81, 82. And the acquisition part 86 and the control part 90 are mainly provided and comprised.

○ Substrate holder 30:
The substrate holding unit 30 is configured to be able to hold the substrate 10 in a substantially horizontal posture. Here, the substrate holding part 30 has a stage 32 in which one main surface is arranged in a substantially horizontal posture upward at a predetermined height position. Then, by placing the substrate 10 on the stage 32 so that one main surface of the substrate 10 is brought into contact with the upward main surface of the stage 32, the substrate 10 can be held at a fixed position and posture. In addition, the substrate holding unit may be configured to hold the substrate by gripping the periphery of the substrate.

  A substrate moving mechanism 34 that moves the substrate 10 relative to the movable coating unit 50 along the Y direction (sub-scanning direction) is provided below the substrate holding unit 30. Here, the substrate moving mechanism 34 includes a base portion 36 that supports the stage 32 and a pair of slide receiving portions 37. The slide receiving portion 37 is provided at the lower end portion of the base portion 36 and is configured to be slidable on the sub-scanning direction guide portion 39 extending along the Y direction. The substrate moving mechanism 34 is configured to move along the Y direction together with the stage 32 and the substrate 10 by receiving a driving force from a substrate movement driving unit (not shown) such as a linear motor. Instead of moving the substrate 10 along the Y direction, the guide unit 40 and the movable coating unit 50 may be moved along the Y direction with respect to the substrate 10.

  The stage 32 sucks and holds the substrate 10 through a suction hole (not shown) provided in a portion where the substrate 10 is placed. The stage 32 may be provided with a heating mechanism for heating the substrate 10 as necessary. Further, the stage 32 may be configured to be rotatable around the vertical axis with respect to the substrate moving mechanism 34.

○ Guide part 40:
The guide portion 40 is a long member formed, for example, in a substantially rectangular bar-like member, extending along the main scanning direction (X direction) substantially parallel to the substrate 10 at a position above the substrate 10. A concave groove that opens upward and extends along the X direction is formed on the upper surface.

○ Main scanning drive mechanism 44:
The main scanning drive mechanism 44 is a drive mechanism that drives the movable coating unit 50 and the counter slider 74 to reciprocate along the X direction, and includes a pair of pulley bodies 46 and 46 provided at both ends of the guide portion 40, A drive belt 48 wound around a pair of pulley bodies 46, 46 and a motor 49 capable of rotationally driving one pulley body 46 in both forward and reverse directions are provided. A belt mounting bracket of the slider 52 is connected and fixed to one side (lower side) of the two paths of the drive belt 48 that travels between the pair of pulley bodies 46 and 46. The counter slider 74 is connected and fixed to the other side (upper side) of the two paths of the drive belt 48 that travels between the pair of pulley bodies 46, 46. The counter slider 74 is disposed at a substantially symmetrical position with respect to the movable coating unit 50 with the central position of the movable coating unit 50 in the reciprocating range (usually the central position of the pair of pulley bodies 46, 46) interposed therebetween. Thus, the drive belt 48 is connected and fixed. The slider 52 and the movable coating unit 50 are driven to reciprocate along the X direction by rotationally driving the motor 49 while controlling the rotational direction, rotational speed, rotational amount, and the like. At this time, the counter slider 74 is configured to reciprocate along the X direction while maintaining a symmetrical position with respect to the movable coating unit 50 with the central position in between.

  The mechanism for driving the movable coating unit 50 and the counter slider 74 is not limited to the above example, and various rotation driving devices other than a motor can be used. The transmission may be performed via a transmission mechanism such as various gears.

○ Movable application unit 50:
The movable application unit 50 includes a slider 52 and a discharge unit 60, and is supported by the guide unit 40 so as to be capable of reciprocating along the X direction.

Slider 52:
The slider 52 is a substantially rectangular parallelepiped member having an internal space in which the guide portion 40 can be inserted and arranged. An air discharge portion is formed on the inner peripheral surface of the internal space. The air supplied through the air discharge section is discharged from the air discharge section.

  A substantially rectangular parallelepiped belt mounting bracket projects from the upper surface (+ Z side surface) of the internal space in the −Z direction in the concave groove of the guide portion 40 inserted and arranged in the slider 52. . There is a slight gap between the belt mounting bracket and the groove, and a drive belt 48 for driving the slider 52 along the groove on the lower surface (the surface on the −Z side) of the belt mounting bracket. Is installed.

  The slider 52 of the movable application unit 50 is supported in a non-contact manner with respect to the outer peripheral surface of the guide portion 40 by interposing an air layer discharged between the internal space and the guide portion 40. The drive belt 48 moves at high speed and high acceleration along the X direction.

  However, each of the above configurations is not essential. For example, the guide portion may have a simple square bar shape or a round bar shape, and a configuration in which a slightly larger internal space than the simple square bar shape or the round bar shape is formed in the slider. Moreover, the guide part may be comprised by the some rod-shaped member. In addition, when an air layer is interposed between the guide portion and the slider, the case where the force is caused by the action of other forces such as the repulsive force of the magnetic force as well as the case of the action of the air pressure ejected between them. Including. Further, for example, a configuration in which the slider is moved along the X direction in a state where the slider is contact-supported by a linear guide or the like may be employed.

-Discharge unit 60:
The discharge unit 60 is supported by the slider 52 and is configured to discharge the coating liquid onto the substrate 10. Here, the discharge section 60 has a nozzle support section 62 and at least one nozzle 64, and a thick plate-like interposition is provided on one side face substantially parallel to the XZ plane among the side faces of the slider 52. It is fixedly attached via an attachment member 55.

  A plurality of (here, three) nozzles 64 are fixedly attached to the nozzle support portion 62 while shifting their positions in the X direction and the Y direction. In addition, the number of the nozzles 64 should just be one or more, and more nozzles may be provided. Each nozzle 64 has a discharge port capable of discharging the coating liquid, and is fixed to the nozzle support portion 62 in a posture in which the discharge port faces downward (−Z direction). In addition, air is supplied from the air supply source 96 to the slider 52 via the piping member 80, and the coating liquid is supplied from the coating liquid supply source 98 to the nozzles 64 via the piping members 80 and 81. It has become. The application liquid is applied to the substrate 10 placed on the stage 32 by discharging the application liquid from each nozzle 64 while moving the slider 52 in the X direction. The coating liquid discharged from the nozzle 64 is usually applied in a stripe pattern in a groove between a plurality of partition walls formed on the substrate 10, but the coating liquid is applied to a substrate on which no partition walls are provided. Even if it does not impair the usefulness of the present invention.

○ Counter guide section 70:
The counter guide portion 70 is two long rod-like members extending along the X direction, and is provided above the guide portion 40 (above the Z direction) to support the counter slider 74 so as to be movable. is doing.

○ Counter slider 74:
The counter slider 74 is a member having an internal space through which the counter guide portion 70 can be inserted. An air discharge portion is formed on the inner peripheral surface of the internal space, and air supplied from the air supply source 96 via the piping member 82 is discharged from the air discharge portion. The counter slider 74 is in a state in which an air layer is interposed between the counter slider 74 and the counter guide portion 70 by discharging air from the air discharge portion while the counter guide portion 70 is inserted into the internal space. (That is, in a state where it floats with respect to the outer peripheral surface of the counter guide portion 70) and is supported so as to be movable along the X direction. The upper side of the two-path drive belt 48 that travels between the pair of pulley bodies 46 and 46 is connected and fixed to the lower surface (−Z side surface) of the counter slider 74. The belt 48 reciprocates along the X direction.

  For example, the counter slider may be configured to be movably supported in contact with the elongated counter guide portion via another low friction member, a rolling element, or the like. .

○ Piping members 80 and 81:
The piping member 80 is a part of the plurality of coating liquid pipings that guides the coating liquid as a fluid to each of the plurality of nozzles 64 of the movable coating unit 50 and the air for guiding air as a fluid to the slider 52. The pipes are bundled to form one pipe member. Further, the piping member 81 is configured as a single piping member by bundling the remaining plurality of coating liquid pipings.

  These piping members 80 and 81 are flexible linear members that can be deformed so that one end of the piping members 80 and 81 (the end on the upstream side in the fluid feeding direction) is the guide portion 40. Are fixed to the two pipe fixing portions 84 supported in a cantilever manner by the mounting frame 22 provided at an upper position of one end portion (−X side end portion) of the X-axis, The other end portion of the piping member 80 and the other end portion of the piping member 81 are divided on both sides of the movable coating unit 50 with the shaft of the guide portion 40 interposed therebetween, and are fixed to the movable coating unit 50, respectively. . These piping members 80 and 81 are also called main scan tubes. The pipe fixing portion 84 and the air supply source 96 or the coating liquid supply source 98 are connected by an extended portion of the pipe members 80 and 81 or another pipe. Further, the axis of the guide part 40 is the center position in the width direction of the guide part 40 and normally coincides with the center of gravity of the movable application unit 50 in the Y direction.

  In addition, slider side pipe fixing portions 58 and 59 are attached and fixed to both sides of the slider 52 (both sides in the Y direction) so as to extend above the slider 52. The other end of the piping member 80 (the end on the downstream side in the fluid feeding direction) is in a substantially vertical posture (attitude along the Z direction) on the outer surface side of the slider-side piping fixing portion 58 on the discharge portion 60 side. The fixed portion is further drawn toward the slider 52 or each nozzle 64, and is connected to the slider 52 or each nozzle 64 so that each fluid can be supplied. Further, the other end portion (the end portion on the downstream side in the fluid feeding direction) of the piping member 81 is fixed to the outer surface side of the slider-side piping fixing portion 59 on the nozzle counter 56 side in a substantially vertical posture (attitude along the Z direction). The fixed portion is further routed toward each nozzle 64 and connected to each nozzle 64 so that fluid can be supplied. The fixing points of the piping members 80 and 81 are not limited to the above example, and may be directly fixed to the slider 52 or may be fixed to the discharge unit 60.

  The arrangement of the air pipe and the coating liquid pipe in the movable coating unit 50 is not limited to the example of the pipe members 80 and 81, and the air pipe and the coating liquid pipe However, if the movable coating unit 50 is moved along the X direction so that air and coating liquid can be supplied to the slider 52 and the nozzle 64, respectively, the usefulness of the present invention is not impaired. Absent.

○ Piping member 82:
The piping member 82 is a flexible linear member that can be deformed so as to have a counter piping that guides air as a fluid to the counter slider 74.

  Usually, this piping member 82 has one piping. One end of the pipe member 82 (the end on the upstream side in the fluid feeding direction) is a pipe supported in a cantilever manner by the mounting frame 22 provided at a position above the one end (+ X side end) of the guide part 40. While being fixed to the fixing portion 84 in a posture extending along the X-axis direction, the other end portion of the piping member 82 is connected and fixed in a state where air can be supplied to the counter slider 74. The pipe fixing portion 84 and the air supply source 96 are connected by an extended portion of the pipe member 82 or another pipe.

  With the above-described configuration, the piping members 80, 81, and 82 move along the plane including the X direction (here, the vertical plane including the X direction, that is, the XZ plane, hereinafter simply as the movable coating unit 50 moves). It is arranged to bend along a vertical plane). Here, the pipe member bending along the vertical plane means a case where the pipe member is bent mainly in the vertical plane within a range in which interference between adjacent pipe members can be suppressed. There is no need to bend only along the direction.

  Here, the piping members 80 and 81 to the movable coating unit 50 are curved so as to be convex in the same direction, more specifically, convex to the other end side (+ X direction) of the guide portion 40. It is arranged. More specifically, the pipe member 82 to the counter slider 74 protrudes in a direction different from the above between the pipe members 80 and 81, more specifically, one end side (−X And curved so as to be convex in the direction).

○ Acquisition unit 86:
The acquisition unit 86 includes, for example, an input / output interface such as a USB interface, a multimedia drive, and an interface for connecting to a LAN and the Internet such as a network adapter, and exchanges data with the control unit 90. Is what you do. Further, the acquisition unit 86 directly receives the film thickness data 2 (FIG. 2) of the coating film on the substrate measured using a film thickness measuring device such as an interferometer from the film thickness measuring device connected to the acquisition unit 86. The information is acquired, received by receiving a storage medium 88 such as an optical disk in which the film thickness data 2 is recorded, or acquired via a network, and supplied to the control unit 90.

○ Control unit 90:
The control unit 90 is configured by a general microcomputer including a CPU, a ROM, a RAM, and the like, and performs operation control of the entire coating apparatus 20 by performing operation control of the coating apparatus 20 according to a software program stored in advance. Control. Here, the control unit 90 supplies air from an air supply source 96 (to be described later), starts supplying the coating liquid from the coating liquid supply source 98, and discharges the coating liquid from each nozzle 64. A process for driving and controlling the motor 49 is performed so as to move the unit 50 along the X direction. In addition, when the movable coating unit 50 is moved by driving control of the motor 49, the control unit 90 performs driving control of the motor 49 based on the film thickness data 2 acquired from the acquiring unit 86, so that the coating is performed on the substrate. Control to improve the uniformity of the film thickness of the coating solution. This control will be described later.

<About film thickness variation and countermeasures against the variation:>
○ About fluctuation of coating film thickness:
FIG. 3 is a diagram illustrating an example of the relationship between the discharge flow rate of the coating liquid and the film thickness of the coating film. More specifically, FIG. 3 shows a process in which the movement of the ejection unit 60 in the main scanning direction (also simply referred to as “main scanning”) is performed once with the substrate 10 stopped at a predetermined position in the sub-scanning direction. 4 shows a change in the moving speed of the discharge unit 60, a change in the discharge flow rate of the coating liquid discharged from the nozzle 64, and a change in the film thickness of the coating film formed on the substrate 10, respectively.

  The moving speed distribution 7a shown in FIG. 3 illustrates the movement speed variation at each position in the main scanning direction of the ejection unit moving in the main scanning direction. Coordinates x1 and x2 indicate the coordinates of both ends of the substrate 10 in the main scanning direction, respectively. As shown in the movement speed distribution 7a, when the ejection unit 60 moves in the main scanning direction, first, the ejection unit 60 is accelerated from the stop state and reaches a constant speed at the coordinate x1, and then the section (x1) where the substrate 10 exists. ˜x2) and then decelerated and stopped.

  Further, the flow rate fluctuation line 6 shown in FIG. 3 indicates the discharge flow rate of the coating liquid discharged from the discharge unit 60 in the process of moving the discharge unit 60 in the main scanning direction while changing the movement speed along the movement speed distribution 7a. This illustrates the fluctuations. Here, the coating liquid supply source 98 is provided with, for example, an MFC, and the MFC makes the discharge flow rate of the coating liquid discharged from the nozzle 64 constant. The pipe members 80 and 81 that supply the coating liquid from the pipe to the discharge unit 60 bend as the discharge unit 60 moves in the main scanning direction, and the volume variation in the pipe member that occurs when the discharge member 60 is bent, Due to the inertial force applied to the coating liquid at the time of deceleration, it is difficult to make the discharge flow rate of the coating liquid actually discharged from the nozzle 64 constant. Fluctuate as shown.

  It should be noted that the variation of the discharge flow rate of the coating liquid in the main scanning process is such that the movement direction of the discharge unit 60 in the main scan, that is, the discharge unit 60 is main-scanned in the forward direction or main-direction in the return direction. This differs depending on whether the scanning is performed, and also varies depending on each position of the substrate in the sub-scanning direction with respect to the ejection unit. However, the variation mode of the discharge flow rate of the coating liquid in the main scanning process has reproducibility for each movement direction along the main scanning direction of the discharge unit 60 and for each position in the sub-scanning direction of the substrate with respect to the discharge unit. . Therefore, when the coating apparatus 20 forms a coating film on the substrate 10 by the same control, the thickness of the coating film in each part on the substrate 10 is also reproducible.

  The cross section 4a shown in FIG. 3 is a cross section in the main scanning direction of the coating film formed on the substrate 10 in accordance with the fluctuation when the discharge flow rate of the coating liquid fluctuates along the flow rate fluctuation line 6 by the main scanning. Is shown. In the upper section of the substrate 10 (the section from the coordinate x1 to the coordinate x2 of the moving speed distribution 7a), since the ejection unit 60 has a constant speed, the film thickness of the coating film varies as illustrated in the cross section 4a.

  In addition, the average film thickness of the coating film formed on the substrate 10 is usually several um, and the variation amount of the film thickness of the coating film is usually about several percent of the average film thickness. The fluctuation amount of the film thickness of the cross section 4a shown in FIG. 3 and the fluctuation amount of the discharge flow rate of the coating liquid are exaggerated for easy understanding. Similarly, in the other drawings (FIGS. 7 to 10) of the present application, the fluctuation amount of the film thickness is appropriately exaggerated with respect to the average film thickness.

  FIG. 4 is a diagram showing an example of the film thickness distribution of the coating film 4 formed on the substrate 10. The main scanning line 3 indicates a movement path of the ejection unit 60 on the substrate 10 when the ejection unit 60 moves from one end to the other end of the substrate 10 in the main scanning direction (X-axis direction) in one main scanning. Is a line. The main scanning line 3 is, for example, an arrow 12 from one end on the + Y side to one end on the −Y side of the substrate 10 as the substrate 10 moves stepwise relative to the ejection unit 60 in the sub-scanning direction (Y-axis direction). Move along. As described above with reference to FIG. 3, the film thickness of the coating film 4 varies depending on, for example, a portion on the substrate 10 as indicated by the contour line 5, so that the cross-sectional shape of the coating film along the main scanning line 3. For example, the shape of the cross section 4a shown in FIG. 3 usually changes for each position of the main scanning line 3 in the sub-scanning direction. Such a variation in the film thickness of the coating film can be measured using a film thickness measuring device such as an interferometer, for example, and the measurement result can be acquired as film thickness data. Note that the film thickness of the coating film formed on the substrate 10 is non-uniform when, for example, the organic EL display device manufactured by applying the organic EL liquid as a coating liquid emits the organic EL. Cause uneven brightness.

○ Measures against fluctuations in coating film thickness:
In the coating device 20, the coating liquid is preliminarily applied to the substrate based on predetermined control conditions such as the discharge flow rate of the coating liquid, the moving speed of the discharging unit 60 in the main scanning direction, and the step movement amount of the substrate 10 in the sub-scanning direction. A trial operation for forming a coating film on the substrate 10 is performed by moving the ejection unit 60 relative to the substrate 10 while ejecting the film on the substrate 10, and film thickness data of the coating film formed by the trial operation is acquired. To do. Then, the coating apparatus 20 determines the moving speed of the ejection unit 60 for forming the coating film with a desired film thickness in the main scanning direction of the ejection unit 60 based on the film thickness data and the control conditions related to the trial operation. The moving speed data is calculated for each position and for each position of the ejection unit 60 with respect to the substrate 10 in the sub-scanning direction. The coating apparatus 20 is formed on the substrate 10 by controlling the movement speed of the discharge unit 60 based on the calculated movement speed data in the present operation for forming a coating film with improved uniformity of film thickness. To improve the uniformity of the coating film thickness. In addition, in the coating device 20 which concerns on embodiment, the control part 90 is comprised so that the improvement method 1 and the improvement method 2 which are demonstrated below can be applied selectively based on a setting.

・ Improvement method 1:
As described above, the fluctuation amount of the film thickness with respect to the average film thickness of the coating film is usually about several percent of the average film thickness. Therefore, in the improvement method 1, it is assumed that the discharge flow rate of the coating liquid at each point on the substrate 10 does not change even if the moving speed of the discharge unit 60 in the main scanning direction changes. Then, the moving speed data of the ejection part 60 for improving the uniformity of the coating film thickness is obtained.

  FIG. 5 shows a curve of the relationship between the moving speed of the discharge unit 60 in the main scanning direction and the film thickness of the coating film at one point on the substrate 10 on the assumption that the discharge flow rate of the coating liquid does not fluctuate. It is a figure illustrated as 8a. Assuming that the discharge flow rate of the coating liquid does not fluctuate, the moving speed of the discharge unit 60 at the one point in the main scanning direction and the film thickness of the coating film have an inversely proportional relationship as shown by the curve 8a. . That is, there is a negative correlation between the moving speed of the ejection unit 60 in the main scanning direction and the thickness of the coating film.

  In FIG. 5, at point 9a, the moving speed of the ejection unit 60 in the main scanning direction is v1, and the thickness of the coating film is d1. In this case, the moving speed vg in the main scanning direction of the discharge section 60 at the point 9g where the coating film thickness is dg is given by the equation (1).

  Therefore, first, the film thickness data of the coating film formed on the substrate 10 by the trial operation is measured using a film thickness measuring machine such as an interferometer, and then the substrate 10 acquired based on the film thickness data. The film thickness d1 at one point is specified, and the moving speed v1 of the discharge unit 60 at the one point is specified based on the control information of the discharge unit 60 in the trial operation, and is substituted into the equation (1). Thus, in this operation, the moving speed vg of the discharge unit 60 for obtaining the reference film thickness dg at the one point is calculated. Similarly, for other points on the substrate 10, the moving speed of the discharge unit 60 for obtaining the reference film thickness dg is calculated in the same manner, thereby obtaining the reference film thickness dg at each point on the substrate 10. 60 moving speed patterns can be obtained.

  Next, an example of improving the film thickness uniformity in this operation by the improvement method 1 will be described. FIG. 7 and FIG. 9 are diagrams each showing an example of the relationship between the moving speed distribution of the ejection unit 60 in the main scanning direction and the film thickness variation of the coating film in the trial operation. 7 and 9, the movement of the ejection unit 60 in the main scanning direction is performed according to the movement speed distribution indicated by the movement speed distribution 7a, and the existence section of the substrate 10 in the main scanning direction (X-axis direction). The moving speed v1 of the discharge unit 60 at x1 to x2 is constant.

  In FIG. 7, the shape of the cross section 4b in the main scanning direction of the coating film formed on the substrate 10 is a trapezoidal shape, and the coating film is located at the end on the −X side of the substrate 10, that is, at the position of the coordinate x1 in the main scanning direction. The film thickness of the coating film is the thickest dg, and as the coordinate in the main scanning direction on the substrate 10 increases, the film thickness of the coating film decreases linearly and becomes the thinnest at the coordinate x2 in the main scanning direction. .

  In FIG. 9, the cross section 4d of the coating film in the main scanning direction has a maximum film thickness dg at a position slightly on the + X side from the center of the coordinates x1 to x2 in the main scanning direction. The film thickness decreases as the coordinate decreases, and the film thickness decreases as the X coordinate of the coating film increases from the position. 7 and 9, the film thickness dg is a desired film thickness (reference film thickness) in the actual operation of forming the coating film.

  FIGS. 8 and 10 are diagrams showing examples in which the uniformity of the coating film thickness distribution in the trial operation shown in FIGS. 7 and 9 is improved in this operation using the improvement method 1, respectively. The graph shows the relationship between the movement speed distribution of the ejection unit 60 in the main scanning direction and the variation in the film thickness of the coating film after the uniformity of the film thickness distribution is improved.

  In FIG. 8, the moving speed distribution 7b shows the moving speed distribution of the discharge part 60 in this operation. In the movement speed distribution 7b, the movement speed of the ejection unit 60 at each position in the section where the coordinates in the main scanning direction of the substrate 10 are x1 to x2 is the movement speed distribution of the ejection unit 60 and the coating film thickness distribution in FIG. And the desired film thickness dg is calculated by the equation (1). Then, corresponding to the fact that the film thickness shown in the cross section 4b (FIG. 7) linearly decreases as the X coordinate on the substrate increases, the upper section of the substrate 10 in the moving speed distribution 7b. The movement speed distribution of the discharge unit 60 linearly decreases from the speed v1 as the X coordinate on the substrate increases.

  Further, in the moving speed distribution 7b, the moving speed distribution in the acceleration section and the deceleration section of the discharge unit 60 and the moving speed distribution in the upper section of the substrate 10 are set so as not to cause a step at the boundary of the section. Is done.

  A cross section 4c indicated by a bold line in FIG. 8 is a cross section of the coating film with improved film thickness uniformity. The shape of the cross section 4c is formed corresponding to the movement speed distribution 7b, and the film thickness of the coating film is substantially equal to the desired film thickness dg over the entire region in the main scanning direction. Further, for comparison of the film thickness distribution, the section 4b (shaded portion) in the trial operation is displayed so as to overlap the section 4c in the main operation.

  Similarly, in FIG. 10, the moving speed distribution 7c shows the moving speed distribution of the discharge section 60 in the present operation. In the movement speed distribution 7c, the movement speed of the ejection unit 60 at each position in the section where the coordinates in the main scanning direction of the substrate 10 are x1 to x2 is the movement speed distribution of the ejection unit 60 and the coating film thickness distribution in FIG. And the desired film thickness dg is calculated by the equation (1). Then, the film thickness shown in the cross section 4d (FIG. 9) gradually increases as the X coordinate on the substrate increases to reach the peak value dg, and then gradually decreases. The movement speed distribution of the discharge section 60 in the upper section of the substrate 10 in the movement speed distribution 7c gradually increases as the X coordinate on the substrate increases to reach the fastest speed v1, and then gradually decreases. Yes.

  Further, in the movement speed distribution 7c, the movement speed distribution in the acceleration section and the deceleration section of the discharge unit 60 is similar to the movement speed distribution 7b in the upper section of the substrate 10 and the boundary portion of the section. It is set so as not to cause a step.

  A cross section 4e indicated by a bold line in FIG. 10 is a cross section of the coating film with improved film thickness uniformity. The shape of the cross section 4e is formed corresponding to the moving speed distribution 7c, and the film thickness of the coating film is substantially equal to the desired film thickness dg over the entire region in the main scanning direction. Further, for comparison of the film thickness distribution, the section 4d (shaded portion) in the trial operation is displayed so as to overlap the section 4e in the main operation.

  As described above, according to the improvement method 1, in the portion where the thickness of the coating film in the trial operation is thinner than the reference value, the moving speed of the discharge unit 60 is made slower than that in the trial operation, thereby applying the coating to the portion. The amount of the applied liquid is increased compared to the trial operation, and conversely, the moving speed of the discharge unit 60 is made faster than the trial operation in the portion where the coating film thickness in the trial operation is thicker than the reference value. This makes it possible to reduce the amount of the coating liquid applied to the portion as compared with the trial operation, so that the uniformity of the film thickness of the coating film formed on the substrate 10 in this operation is more than that during the trial operation. Can be improved.

  For example, in the moving speed distributions 7a to 7c in FIGS. 3 and 7 to 10, the relationship of the moving speed of the discharge unit 60 to the position (X coordinate) is displayed, but the movement of the discharge unit 60 with respect to the time axis is displayed. Needless to say, the speed relationship may be used.

・ Improvement method 2:
The improvement method 2 is a trial without assuming the improvement method 1 that the discharge flow rate of the coating liquid at each point on the substrate 10 does not change even if the moving speed of the discharge unit 60 in the main scanning direction changes. Based on a plurality of combinations of the movement speed of the discharge unit 60 in the operation and the film thickness of the coating film, the movement speed of the discharge unit 60 for obtaining a desired film thickness is calculated in this operation.

  FIG. 6 is a diagram illustrating the relationship between the moving speed of the ejection unit 60 in the main scanning direction and the film thickness of the coating film as a curve 8b at one point on the substrate 10. In FIG. The moving speed of the discharge unit 60 and the film thickness of the coating film at points 9b, 9c, and 9d on the curve 8b correspond to the three moving speeds of the discharge unit 60 at the one point in the trial operation, respectively. Each is acquired by acquiring the film thickness data of the coating film to be formed.

  The relationship between the curve 8b, that is, the moving speed of the discharge unit 60 at the one point and the film thickness of the coating film is based on the points 9b, 9c, and 9d obtained by the trial operation. And a function expressing the relationship between the thickness of the coating film and the thickness of the coating film is specified by curve fitting or the like. In this operation, the moving speed vg of the ejection unit 60 for obtaining a desired film thickness dg is calculated by the specified curve 8b. Therefore, the coating apparatus 20 can improve the uniformity of the thickness of the coating film formed on the substrate 10 by applying the improvement method 2.

  In FIG. 6, the relationship between the moving speed of the ejection unit 60 and the thickness of the coating film is specified by curve fitting. However, even if the relationship is specified by, for example, broken line approximation, the usefulness of the present invention is determined. Further, for example, based on the data at the two points 9b and 9c, a linear approximation of the relationship between the moving speed of the discharge unit 60 and the film thickness of the coating film is desirable in this operation. Even if the moving speed vg of the discharge section 60 for obtaining the film thickness dg is calculated, the usefulness of the present invention is not impaired.

  Further, in the actual coating film forming operation, when the moving speed of the discharge unit 60 decreases, the discharge rate of the coating liquid may decrease due to a decrease in the acceleration of deformation of the piping members 80 and 81. That is, there may be a positive correlation between the moving speed of the ejection unit 60 in the main scanning direction and the thickness of the coating film. Here, according to the improvement method 2, the ejection unit 60 is assumed in advance without assuming that the relationship between the moving speed of the ejection unit 60 and the film thickness of the coating film is an inversely proportional relationship, that is, a negative correlation. It is possible to acquire the relationship between the movement speed of the film and the film thickness of the coating film. Therefore, for example, it is assumed that the moving speed of the ejection unit 60 for one point of the substrate 10 along the main scanning line and the film thickness of the coating film have a proportional relationship, that is, a positive correlation as described above. However, by applying the improvement method 2, in a portion where the coating film thickness in the trial operation is thinner than the reference value, the moving speed of the discharge unit 60 is made higher than that in the trial operation to apply to the portion. By increasing the amount of the coating liquid compared to the trial operation, and conversely, in the portion where the coating film thickness in the trial operation is thicker than the reference value, the moving speed of the discharge unit 60 is made slower than that during the trial operation, Since the amount of the coating liquid applied to the portion can be reduced compared to the trial operation, the uniformity of the film thickness of the coating film formed on the substrate 10 in this operation is improved as compared to the trial operation. be able to.

<About operation | movement of the coating device 20:>
Next, the operation of the coating apparatus 20 according to the embodiment will be described. 11 and 12 are diagrams for explaining the operation flow of the coating apparatus 20 according to the embodiment.

  In response to an operation of starting the main operation for forming a coating film with improved film thickness uniformity on the substrate 10, the coating apparatus 20 starts the main operation (step S100), and the acquisition unit 86 performs a trial. Film thickness data is obtained for the coating film previously formed on the substrate 10 by the operation (step S110). Next, the control part 90 starts the calculation process of the moving speed data of the control part 90 in this operation | movement (step S120).

  In the calculation process of the movement speed data of the control unit 90 in this operation, the control unit 90 first acquires the movement speed data of the ejection unit 60 at each point on the substrate 10 in the trial operation via the acquisition unit 86 ( Along with step S121), a desired film thickness (target value of film thickness) stored in advance is acquired by reading from RAM or the like (step S122).

  Next, the control unit 90 sets the main scanning line 3 for calculating the moving speed of the ejection unit 60 (step S123). The main scanning line 3 is set by specifying relative coordinates in the sub-scanning direction of the ejection unit 60 with respect to the substrate 10.

  When the main scanning line 3 to be processed is set, the control unit 90 performs the trial operation at each position of the main scanning line 3 based on the coating film thickness data and the movement speed data of the ejection unit 60 in the trial operation. The film thickness of the coating film and the moving speed of the discharge section 60 are acquired (step S124).

  Next, the control unit 90 applies, for example, the improvement method 1 or the improvement method 2 described above with reference to FIGS. 3 to 10 to make the uniformity of the film thickness of the coating film formed in this operation. Speed data of the ejection unit 60 for improving the movement is calculated for each position of the main scanning line 3 (step S125), and the movement speed data is used to indicate the relationship of the movement speed of the ejection unit 60 with respect to time. (Step S126).

  When the calculation processing of the moving speed data for the main scanning line 3 is completed, the control unit 90 changes the main scanning line 3 that is the calculation target of the moving speed data (step S127), and all the main scanning lines on the substrate 10 are changed. 3 is checked whether or not the calculation process of the moving speed data of the ejection unit 60 for 3 is completed (step S128).

  If the calculation processing for all the main scanning lines 3 has not been completed, the control unit 90 returns the processing to step S125 to calculate the movement speed data of the ejection unit 60 for the new main scanning line 3. If the calculation process of the moving speed data of the ejection unit 60 for all the main scanning lines 3 is completed, the control unit 90 moves the process to step 129 (step S128). In step S129, the control unit 90 stores the movement speed data of the ejection unit 60 in the main operation in a RAM or the like, and moves the process to step S130.

  Next, the control unit 90 starts control of this operation, and initializes the position of the discharge unit 60 in the main scanning direction and the relative position of the discharge unit 60 in the sub-scanning direction with respect to the substrate 10 (step). S130).

  When the initialization of the discharge unit 60 is completed, the control unit 90 starts discharging the coating liquid from the discharge unit 60 based on the discharge flow rate control information in the trial operation, and the discharge unit 60 for the calculated main operation. Based on the moving speed data for the main scanning line 3 among the moving speed data, the ejection section 60 is main-scanned in the forward direction (step S140).

  When the main scanning in the forward direction of the discharge unit 60 is completed, the control unit 90 performs a process of moving the substrate 10 by a predetermined amount in the sub-scanning direction with respect to the discharge unit 60 (step S150). When completed, based on the movement speed data for the main scanning line 3 after the step movement of the calculated movement speed data of the ejection section 60 for the main operation, the ejection section 60 is main-scanned in the backward direction (step S160). ). When the main scanning in the backward direction of the ejection unit 60 is completed, the control unit 90 performs a process of moving the substrate 10 by a predetermined amount in the sub-scanning direction with respect to the ejection unit 60 (step S170).

  Next, the control unit 90 confirms whether or not the main scanning for the predetermined number of main scanning lines 3 necessary for forming the coating film of the coating solution on the substrate 10 is completed (step S180). If all necessary main scans have been completed, this operation is terminated. If all necessary main scans have not been completed, the process returns to step S140 to start main scan in the forward direction of the ejection unit 60. To do.

  By the above-described operation, the coating apparatus 20 moves the ejection unit 60 to improve the uniformity of the coating film thickness based on the coating film thickness data and the movement speed data of the ejection unit 60 in the trial operation. By calculating the speed data and performing the movement control of the discharge unit 60 based on the calculated movement speed data in this operation, the uniformity of the film thickness of the coating film formed on the substrate 10 is more than in the trial operation. Can be improved.

<About modification:>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made.

  For example, in the improvement method 1 and the improvement method 2 described above, in the trial operation, the ejection unit 60 was moved at a constant speed in the upper section of the substrate 10 (FIGS. 7 and 9). However, even if the ejection unit 60 is not moved at a constant speed in the section in the trial operation, it is formed on the substrate 10 in the present operation by applying the improvement method 1 or the improvement method 2 described above. The uniformity of the coating film thickness can be improved as compared with the trial operation.

  In the improvement method 1 and the improvement method 2 described above, the movement speed of the ejection unit 60 is obtained based on the relationship between the movement speed of the ejection unit 60 and the film thickness of the coating film (FIGS. 5 and 6). ) By calculating the discharge flow rate for the coating liquid from the discharge unit from the moving speed of the discharge unit 60 and the film thickness of the coating film, the relationship between the calculated discharge flow rate and the moving speed of the discharge unit 60 is obtained. Even if the moving speed data of the ejection unit 60 for improving the uniformity of the film thickness of the coating film formed on the substrate 10 in this operation is calculated based on this relationship, the usefulness of the present invention is impaired. It is not a thing.

  In the operation flow described above, the movement speed data of the ejection unit 60 is obtained for each main scanning line, and in this operation, the main speed of the ejection unit 60 is determined based on the movement speed data of the ejection unit 60 corresponding to each main scanning line. Although scanning is performed, depending on the required specifications for the uniformity of the coating film thickness, for example, a predetermined main scanning line may vary depending on the thickness of the coating film formed in the sub-scanning direction. The control related to the main scanning of the ejection unit 60 may be applied to all the main scanning lines.

  Further, based on the relationship between the acceleration of the ejection unit 60 and the film thickness of the coating film in the trial operation, or the relationship between the acceleration of the ejection unit 60 and the ejection flow rate of the coating liquid, Even if the acceleration of the discharge unit 60 for improving the film thickness uniformity of the coating film is calculated and the movement speed data of the discharge unit 60 is further calculated, the usefulness of the present invention is not impaired. For example, the control data and the film thickness data in the trial operation are processed with respect to a predetermined portion on the substrate 10 where the film thickness of the coating film formed in the trial operation is thinner than the target value by using the technique focusing on the acceleration of the discharge unit 60. As a result, at the predetermined portion, the discharge unit 60 performs a predetermined acceleration movement, and thus the effect of increasing the film thickness due to the increase in the discharge flow rate due to the inertial force applied to the coating liquid is due to the acceleration of the discharge unit 60. When the characteristic of exceeding the effect of reducing the film thickness due to the shortening of the passage time of the predetermined portion of the discharge unit 60 is obtained, the coating portion of the coating film is accelerated by accelerating the moving speed of the discharge unit 60 for the predetermined portion. The desired film thickness can be obtained by increasing the film thickness.

  For example, even if the coating apparatus 20 does not include the counter guide portion 70, the counter slider 74, and the piping member 82, the usefulness of the present invention is not impaired.

2 Film thickness data 3 Main scanning line 4 Coating film 5 Contour line 10 Substrate 20 Coating device 30 Substrate holding unit 40 Guide unit 44 Main scanning drive mechanism 50 Movable coating unit 52 Slider 60 Discharge unit 64 Nozzle 70 Counter guide unit 74 Counter slider 80, 81, 82 Piping member 84 Piping fixing part 96 Air supply source 98 Coating liquid supply source

Claims (5)

A coating apparatus that forms a coating film by applying a coating solution to a substrate by moving a discharge unit that discharges the coating solution relative to the substrate,
A discharge unit for discharging the coating liquid onto the substrate;
A moving mechanism for moving the ejection unit relative to the substrate;
An acquisition unit that acquires film thickness information of a coating film formed on a trial basis using the discharge unit and the moving mechanism;
A speed changing unit that changes a moving speed of the discharge unit in a relative movement with respect to the substrate according to the film thickness information;
A coating apparatus comprising: The coating apparatus according to claim 1,
There is a negative correlation between the moving speed of the discharge part and the film thickness of the coating film,
The speed changing unit is configured to set a moving speed of the discharging unit for a portion of the substrate where the film thickness information is thicker than a reference film thickness, based on a moving speed of the discharging unit when the coating film is formed on a trial basis. And the moving speed of the discharge section is slower than the moving speed of the discharge section when the coating film is formed on a trial basis for a portion of the substrate where the film thickness information is thinner than a reference film thickness. A coating apparatus characterized by: The coating apparatus according to claim 1 or 2,
The moving mechanism performs main scanning in which the ejection unit is alternately moved relative to the substrate in a predetermined forward direction and a forward direction,
The ejection unit ejects the coating liquid onto the substrate in the forward path and the backward path of the main scanning,
The speed changing unit sets the velocity distribution of the movement speed of the ejection unit in the forward path of the main scanning and the velocity distribution of the movement speed of the ejection unit in the return path of the main scanning so as to be different from each other. A characteristic coating apparatus. The coating apparatus according to claim 1,
There is a positive correlation between the moving speed of the discharge unit and the film thickness of the coating film,
The speed changing unit is configured to set a moving speed of the discharging unit for a portion of the substrate where the film thickness information is thicker than a reference film thickness, based on a moving speed of the discharging unit when the coating film is formed on a trial basis. The moving speed of the discharge section is higher than the moving speed of the discharge section when the coating film is formed on a trial basis for a portion of the substrate where the film thickness information is thinner than the reference film thickness. A coating apparatus characterized by: A coating method for forming a coating film by applying a coating solution to a substrate using a predetermined coating apparatus that moves a discharge unit that discharges the coating solution relative to the substrate,
An acquisition step of acquiring film thickness information of a coating film formed on a trial basis using the coating apparatus;
A speed changing step of changing the moving speed of the ejection unit in relative movement with respect to the substrate according to the film thickness information;
A coating method comprising:

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