WO2015141456A1 - Gap-maintaining method, gap-maintaining device, and coating device - Google Patents

Abstract

A coating device (1) comprising a coating apparatus (5) that coats a substrate (W) with a coating liquid, wherein a gap between the substrate (W) and a discharge port (7a) of the coating apparatus (5) can be kept uniform with high precision and coating can be performed while preventing the occurrence of control operation delays. This gap-maintaining method involves measuring a gap that is formed between: an end part of a reference surface (17) of a protective block (16) provided further towards a pre-coating side of the substrate (W) than the discharge port (7a); and a section, which opposes the end part, of a surface (K) to be coated of the substrate (W). Subsequently, as the section, which was opposing the end part, of the surface (K) to be coated reaches a position opposing the discharge port (7a) as a result of the substrate (W) moving, a gap formed between the discharge port (7a) and the section of the surface (K) to be coated maintains uniformity due to the coating apparatus (5) being moved in the direction orthogonal to the surface (K) to be coated and on the basis of the measured gap.

Description

Gap maintenance method, gap maintenance device and coating device

The present invention is used in the field of manufacturing optical filters, printed circuit boards, integrated circuits, semiconductors, etc., in addition to the field of manufacturing display members such as color filters for color liquid crystal displays, organic EL, and plasma displays. In detail, in order to form a thin coating film by discharging the coating liquid onto a sheet-shaped coated member such as a glass substrate, a gap between the coated member and a coating device that discharges the coating liquid. The present invention relates to a gap maintaining method, a gap maintaining apparatus, and a coating apparatus provided with the gap maintaining apparatus for maintaining a predetermined constant value with high accuracy.

The color liquid crystal display is composed of a color filter, a TFT array substrate, and the like. Manufacturing of color filter and TFT array substrates includes many manufacturing processes in which a low-viscosity liquid material (coating solution) is applied on a glass substrate and dried to form a coating film.

For example, in a color filter manufacturing process, a black photoresist material coating film is formed on a glass substrate, and the coating film is processed into a lattice pattern by a photolithographic method, and then red, blue, and green photoresist materials are formed between the lattices. Are sequentially formed. As an apparatus for forming such a coating film, for example, a coating apparatus as shown in Patent Document 1 is used.

This applicator has a slit nozzle as an applicator, and it moves the coated member such as a glass substrate in one direction while discharging the coating liquid from the slit-like long discharge channel provided in this slit nozzle. By making it, a coating film can be formed in this to-be-coated member.

In order to form a planar coating film on such a coated member as a thin film having a uniform thickness (for example, a wet film thickness of 10 μm or less), a discharge port surface in which the discharge flow path of the applicator is open The gap (also referred to as clearance or gap) formed between the coating member and the coating surface (surface) of the coating member is reduced, and the coating member and the applicator are moved relative to each other on the coating member. Since a thin film is formed, it is necessary to keep the gap constant during the relative movement.

Therefore, Patent Document 2 discloses a means for performing coating while keeping the gap small. In this Patent Document 2, a gap formed between a discharge port surface of a coating device and a portion of a coating surface of a coating member facing the discharge port surface while relatively moving the coated member and the coating device. Value (gap value) is measured. A drive shaft for moving the applicator in the vertical direction is provided, and based on the gap value obtained by measurement, the gap between the discharge port surface and the portion of the surface to be coated facing this is constant. Thus, the vertical position of the applicator is controlled, that is, the drive shaft is controlled. In addition, controlling the position of the applicator so as to make the gap constant according to the gap formed between the application surface and the surface to be applied (surface shape of the application surface) is referred to as “copying control”. .

JP-A-6-339656 JP 2013-148408 A

In the case of Patent Document 2, since the measurement position of the gap coincides with the position of the opening (discharge port) of the discharge flow channel for discharging the coating liquid, the measurement result of the gap is processed instantaneously to control the drive shaft. Even if (feedback control) is performed, a delay occurs, and it is considered impossible to perform exact scanning control.

Accordingly, an object of the present invention is to provide a gap maintaining method and a gap maintaining apparatus for preventing occurrence of a control delay and enabling strict scanning control, and a coating apparatus including the gap maintaining apparatus. To do.

According to the present invention, there is provided a gap formed between a coating liquid discharge port of the applicator and a portion of a coating surface of a coating member to which the coating liquid is applied facing the discharge port. And a gap maintaining method that maintains constant according to the relative movement for application with the applicator, the reference surface of the measurement body provided on the front side of the application in the relative movement direction than the discharge port, The gap formed between the coated surface of the coated member facing the reference surface of the measuring body is measured, and the portion of the coated surface facing the reference surface of the measuring body is the The applicator is moved in a direction perpendicular to the coated surface based on the measured gap in accordance with the relative movement to reach the position facing the discharge port. It is characterized in that a gap formed between the portions is kept constant.

According to the present invention, the reference surface of the measurement body is provided on the front side of the application in the relative movement direction with respect to the discharge port, and the reference surface of the measurement body and the portion of the coated surface of the coated member facing the reference surface Is measured to move the applicator in a direction perpendicular to the surface to be coated until the portion of the surface to be coated reaches a position facing the discharge port by the relative movement. Preparation time can be secured. For this reason, the applicator is moved in a direction perpendicular to the application surface in accordance with the timing at which the portion of the application surface to be measured reaches the position facing the discharge port. The gap formed between the outlet and the portion to be coated can be kept constant. As a result, it is possible to perform the above-described scanning control that was impossible in the past.

In the present invention, “the pre-application side in the direction of relative movement from the discharge port” means that the coating liquid is not yet applied to the member to be coated on the basis of the discharge port that discharges the coating liquid. It is the area side (uncoated area side) to be coated.

The following processing is performed during the preparation time. That is, the applicator is placed on the basis of the measured gap until the portion of the surface to be coated facing the reference surface of the measuring body reaches the position facing the discharge port by the relative movement. Preferably, a control signal for moving in the vertical direction is generated.

In this case, it becomes possible to complete the movement of the applicator when the portion of the surface to be coated that has been subjected to the measurement of the gap has reached the position facing the discharge port due to the relative movement, and the control operation is delayed. Occurrence can be prevented.

The gap is measured by capturing a real image of the end of the reference surface of the measurement body and a reflection image of the end of the reference surface of the measurement body on the surface to be coated of the member to be coated. Preferably, the calculation is performed based on the length between the real image of the end portion and the reflected image of the end portion.

This makes it possible to accurately measure the gap between the reference surface of the measurement body and the portion of the coated surface facing the reference surface.

Further, the gap maintaining device of the present invention includes a measuring body having a reference surface substantially parallel to a discharge port surface including a coating liquid discharge port of a coating device, and a portion of a coated surface of a coated member facing the reference surface. And measuring means for measuring a gap formed between the reference surface and the relative movement for application between the member to be applied and the applicator, and the application based on the measurement value by the measurement means A gap maintaining means for maintaining a constant gap between the discharge port surface and the portion of the coated surface by moving a container in a direction perpendicular to the coated surface, and the measuring body comprises: It is provided on the front side of the application in the relative movement direction with respect to the discharge port surface.

According to the present invention, the reference surface of the measurement body is provided on the front side of application in the relative movement direction with respect to the discharge port surface, and the reference surface of the measurement body and the application surface of the application member facing the reference surface are provided. When the gap with the portion is measured, the applicator is moved in a direction perpendicular to the application surface until the portion of the application surface reaches the position facing the discharge port by the relative movement. The preparation time can be secured. For this reason, the applicator is moved in a direction perpendicular to the application surface in accordance with the timing at which the portion of the application surface to be measured reaches the position facing the discharge port. The gap formed between the exit surface and the portion to be coated can be kept constant. As a result, it is possible to perform the above-described scanning control that was impossible in the past.

Further, the gap maintaining means includes an elevating mechanism for moving the applicator in the vertical direction and a portion of the coated surface facing the reference surface of the measuring body to the discharge port by the relative movement. It is preferable to have a controller that generates a control signal for moving the applicator in the vertical direction based on the measurement value obtained by the measurement means until the opposite position is reached.

As a result, when the gap is measured by the measuring means, the control signal is generated until the portion of the coated surface that is the object of measurement reaches the position facing the discharge port by the relative movement. Then, when the portion of the surface to be coated reaches the position facing the discharge port by the relative movement, the movement of the applicator can be completed, and the occurrence of a delay in the control operation can be prevented.

Further, the measurement body including the reference surface may be integrated with the applicator.

In addition, the measurement unit is an imaging unit that captures a real image of an end portion of the reference surface of the measurement body and a reflection image of an end portion of the reference surface of the measurement body on the coated surface of the coated member; It is preferable that the image processing apparatus further includes calculation means for calculating the gap based on a length between the captured real image of the end portion and the reflected image of the end portion.

This makes it possible to accurately measure the gap between the reference surface and the surface to be coated.

In addition, the coating apparatus of the present invention includes an applicator having a discharge port for discharging a coating liquid to a member to be coated, a coating liquid supply means for supplying the coating liquid to the coating device, A moving mechanism that relatively moves the coating member in a direction parallel to the coated surface of the coated member, and the gap maintaining device are provided.

According to the present invention, it is possible to perform application with strict scanning control, which was impossible in the past.

According to the present invention, when the gap between the reference surface of the measuring body and the portion of the coated surface of the coated member facing the reference surface is measured, the portion of the coated surface that is the object of measurement is discharged. By moving the applicator in a direction perpendicular to the surface to be coated in accordance with the timing of reaching the position facing the outlet, the gap formed between the discharge port and the portion of the surface to be coated is made constant. Since it can be maintained, it is possible to perform the strict scanning control that was impossible in the past.

It is a schematic diagram explaining schematic structure of a coating device. It is explanatory drawing which looked at the coating apparatus shown in FIG. 1 from the side. It is explanatory drawing of a gap maintenance apparatus. It is a perspective view which shows an applicator, a protection block, a reference | standard base member, the raising / lowering unit containing a raising / lowering bar, a board | substrate, etc. FIG. It is a perspective view which shows the condition where the imaging means is imaging the real image of the lower surface edge part which is a reference surface of a measurement body, and the reflected image of the said lower surface edge part on a board | substrate. It is explanatory drawing of the image which the imaging means imaged. FIG. 6 is a perspective view showing a state where the protection block is raised by a predetermined amount from the state shown in FIG. 5. It is explanatory drawing of the image which the imaging means imaged. It is explanatory drawing of a space | gap measurement preparation process. (A) And (B) is explanatory drawing of a board | substrate carrying-in / gap confirmation process, (C) is explanatory drawing of an application | coating and board | substrate carrying-out process. It is explanatory drawing explaining the specific example of copying control. It is a flowchart of the coating method. It is a flowchart of the coating method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[About coating device 1]
FIG. 1 is a schematic diagram illustrating a schematic configuration of the coating apparatus 1. FIG. 2 is an explanatory view of the coating apparatus 1 shown in FIG. 1 as viewed from the side (X direction). The coating apparatus 1 is an apparatus that applies a coating liquid to the surface of a substrate W that is a member to be coated, and a coating film is formed on the substrate W by the coating liquid.

The coating apparatus 1 includes a base 2, a gantry 4 mounted on the base 2, and an applicator (nozzle) having a discharge port 7 a that discharges a coating liquid onto a surface to be coated K that is the surface of the substrate W. 5. Coating liquid supply means 10 for supplying the coating liquid to the coating device 5, a moving mechanism 8 for relatively moving the coating device 5 and the substrate W in a direction parallel to the surface to be coated K, and moving the coating device 5 in the vertical direction. A lifting mechanism 9 is provided, and a control device 11 including a computer is provided.

The control device 11 has a program for causing the applicator 5 to apply the coating liquid and a gap formed between the discharge port surface 18 of the applicator 5 and the application surface K to be kept constant. The program is stored. The control device 11 executes these programs to generate a control signal for controlling the operation of each mechanism included in the coating device 1, and based on the control signal, the ejection port surface 18, the coating surface K, and the like. The coating liquid is applied to the substrate W while keeping the gap of the substrate constant. The discharge port surface 18 is a surface of the lower surface of the applicator 5 where the discharge port 7a is opened.

A single wafer-like substrate W is placed on a stage 3 to be described later. The upper surface of the stage 3 forms a horizontal plane. And the relative movement direction of this board | substrate W and the applicator 5 is a horizontal direction, this relative movement direction is set to X direction, and the horizontal direction orthogonal to this X direction is set to Y direction. A direction perpendicular to the X direction and the Y direction is taken as a Z direction. The Y direction is the width direction of the substrate W and coincides with the longitudinal direction of the applicator 5. The Z direction is the height direction and coincides with the moving direction of the applicator 5 by the lifting mechanism 9.

The gantry 4 is installed on the base 2 so as to be movable in the X direction, and the applicator 5 is mounted on the gantry 4. The applicator 5 (see FIG. 1) has a manifold 6 and a discharge flow path 7 connected to the manifold 6 therein. The manifold 6 is composed of an enlarged space for storing the coating liquid supplied from the coating liquid supply means 10 and then sending it to the discharge flow path 7. The discharge flow path 7 is for discharging the coating liquid to the substrate W. It is a flow path. The end of the discharge flow path 7 opposite to the manifold 6 side (the lower end in the present embodiment) is a coating liquid discharge port 7a, and the coating liquid is discharged from the discharge port 7a. The discharge channel 7 is a slit-shaped channel, and a planar coating film is formed on the substrate W.

The moving mechanism 8 includes a stage 3 for fixing the substrate W by suction or the like, a linear motor 8a whose operation is controlled by the control device 11, and a guide member 8b for guiding the stage 3 in the X direction. The moving mechanism 8 of the present embodiment is configured to move the stage 3 on which the substrate W is placed in a direction parallel to the surface to be coated K with respect to the applicator 5 when coating the substrate W. In each drawing including FIG. 1, the moving direction of the stage 3 (substrate W) for coating is indicated by an arrow X1.

The moving mechanism 8 causes the coating liquid supplied from the coating liquid supply means 10 to be discharged from the discharge port 7a of the applicator 5 while moving the stage 3 on which the substrate W is placed on the applicator 5 in the X1 direction. Thus, a coating film can be formed on the substrate W. The moving mechanism 8 may be configured to move at least one of the applicator 5 and the substrate W (stage 3) for coating, and the gantry 4 is movable in the X direction with respect to the base 2. Therefore, the gantry 4 may function as the moving mechanism 8 for application. That is, the applicator 5 mounted on the gantry 4 may be configured to move in a direction parallel to the application surface K with respect to the substrate W (stage 3).

The elevating mechanism 9 is installed in the gantry 4, and a servo motor 9a whose operation is controlled by the control device 11, a screw shaft 9b whose axial direction is the Z direction rotated by the servo motor 9a, and the screw shaft 9b And a nut unit 9c that is screwed onto the nut. The applicator 5 is attached to the nut unit 9c via the elevating bar 13 and the reference base member 14. A protective block (measuring body) 16 that is a separate body from the applicator 5 is also fixed to the reference base member 14. The nut unit 9c moves up and down along the screw shaft 9b by forward and reverse rotation of the screw shaft 9b, and moves the applicator 5 and the protection block 16 (measurement body) up and down as a unit.

According to the elevating mechanism 9, the height position of the discharge port 7a (discharge port surface 18) with respect to the substrate W (application surface K) can be adjusted, and the discharge port 7a (discharge port surface 18) and the substrate W can be adjusted. It is possible to adjust a gap (also referred to as a clearance or a gap) formed between the (coated surface K). The lifting mechanisms 9 are provided at both ends in the Y direction, and can operate independently. For this reason, when the coated surface K of the substrate W on the stage 3 is inclined along the Y direction, the heights on both sides in the Y direction of the applicator 5 can be adjusted in accordance with the inclination. It is possible to make the gap constant along the Y direction.

The coating liquid supply means 10 (see FIG. 1) includes a flow path 24 connected to the manifold 6 of the applicator 5, a pump 22 as a liquid feeder for sending the coating liquid to the applicator 5 through the flow path 24, and a coating liquid. And a tank 23 for storing. The pump 22 is a constant capacity pump that sends the coating liquid to the applicator 5 at a constant flow rate, and the pump 22 of the present embodiment is a syringe pump.

The applicator 5 is fixed to the reference base member 14, and a protective block 16 that is separate from the applicator 5 is also fixed to the reference base member 14. The protection block 16 has the same width dimension (dimension in the Y direction) as the discharge port surface 18 of the applicator 5 and, as shown in FIG. 1, the coating front side (left side in the case of FIG. 1) from the discharge port 7a. Is provided. The lower surface end of the protective block 16 (reference surface 17 described later) is closer to the substrate W than the discharge port surface 18 including the discharge port 7 a of the applicator 5. The position is set. Thereby, when the foreign substance exists on the substrate W, or when the coated surface K of the substrate W is raised by the foreign substance existing between the substrate W and the stage 3, the movement of the substrate W in the arrow X1 direction is performed. As a result, the foreign matter and the surface to be coated K first collide (detect) with the lower end of the protective block 16, and the foreign matter collides with the discharge port 7a (discharge port surface 18) of the applicator 5. Can be prevented in advance.

And in this embodiment, the said lower surface edge part of this protection block 16 becomes the reference surface 17 for the measurement means 21 mentioned later to perform a measurement. The reference surface 17 is a surface different from the discharge port surface 18 and is formed as a surface substantially parallel to the discharge port surface 18 on the lower surface of the protection block 16. As described above, since the protective block 16 is provided on the rear side in the movement direction of the substrate W with respect to the discharge port 7a, the reference surface 17 is also on the front side of the application with respect to the discharge port 7a (discharge port surface 18). It becomes the composition provided in. As described above, the protection block 16 functions as a member that prevents a foreign object from colliding with the discharge port 7 a and also functions as a measurement body having the reference surface 17.

Although not shown, as a configuration other than providing the reference surface 17 on the protection block 16, a measuring body different from the applicator 5 and the protection block 16 is disposed on the front side of the application from the discharge port 7a (discharge port surface 18). It may be provided separately, and the lower surface end of the measurement body may be used as the reference surface 17. Or you may provide the reference surface 17 in the X direction edge part of the lower surface of the applicator 5, ie, the end part before application | coating of the discharge port surface 18 integrally with the applicator 5. FIG.
[Gap Maintenance Device 20]
FIG. 3 is an explanatory diagram of the gap maintaining device 20, in which the imaging means 21 a is between the reference surface 17 of the protection block 16 and the portion p of the surface to be coated of the substrate W located immediately below the reference surface 17. This represents a situation where the gap value C to be formed is measured. As shown in FIG. 3, the coating device 1 includes a gap maintaining device 20, and this gap maintaining device 20, when performing coating, discharges the discharge port 7 a (discharge port surface 18) of the applicator 5 and the discharge port. A gap (gap value Cn) formed between a part of the coated surface K of the substrate W to which the coating liquid is applied facing the outlet 7a is moved in the direction of arrow X1 of the substrate W with respect to the applicator 5. In addition, it has a function to maintain a constant value. For this purpose, the gap maintaining device 20 includes a protection block 16 having the reference surface 17, a measuring unit 21, and a gap maintaining unit 25.

The measuring means 21 measures the value of the gap (gap value C) formed between the reference surface 17 and the portion p of the coated surface of the substrate W facing the reference surface 17. Here, since the reference surface 17 faces downward, “the portion of the coated surface facing the reference surface 17” becomes “the portion of the coated surface located directly below the reference surface 17”. Similarly, since the discharge port 7a is opened downward, “the portion of the coated surface facing the discharge port surface 18 including the discharge port 7a” is “a surface located immediately below the discharge port surface 18”. "

The measuring means 21 of the present embodiment includes, for example, an imaging means 21a composed of a camera mounted on the gantry 4, a monitor means 21c for displaying an image taken by the imaging means 21a, and an image taken by the imaging means 21a. And calculating means 21b for calculating the gap value C.

FIG. 4 is a perspective view showing the applicator 5, the protection block 16, the reference base member 14, the lifting unit including the lifting bar 13, the substrate W, and the like. As shown in FIG. 4, the imaging means 21 a is provided at both ends in the Y direction, and images a part of each of the protection block 16 and both ends in the Y direction of the substrate W.

The imaging means 21a includes an imaging element, a lens for imaging an imaging target with a predetermined size, and illumination for imaging with a predetermined brightness. It is preferable to use a CCD (Charge Coupled Device) that is widely used for image processing as the imaging device. The size of a semiconductor element, which is one pixel of a CCD, is about several μm, and the pixels are arranged in units of several hundred to several thousands in the vertical and horizontal directions.

The calculation means 21b has an image processing function, processes the image acquired by the imaging means 21a, and obtains the gap value C by calculation. The calculation means 21b of this embodiment consists of a part of function with which the said control apparatus 11 which is a computer is equipped. The gap value C calculated by the calculation means 21b is transmitted to the controller 12 described later. In the present embodiment, the controller 12 also includes a part of functions provided in the control device 11 that is a computer.

As described above, the elevating mechanism 9 can elevate and lower the applicator 5 in the Z direction (a direction perpendicular to the application surface K), thereby adjusting the height position of the discharge port surface 18. Further, the coating apparatus 1 includes the controller 12 that generates a control signal for moving the applicator 5 up and down in the Z direction by the lifting mechanism 9 and controls the operation of the lifting mechanism 9 and the moving mechanism 8. ing.

The gap maintaining means 25 is constituted by the lifting mechanism 9 and the controller 12. Based on the measured value by the measuring means 21, that is, the measured value (gap value C) of the gap formed between the reference surface 17 and the portion p of the coated surface located immediately below the reference surface 17, the controller 12 generates a control signal for raising and lowering the applicator 5 in the Z direction by the elevating mechanism 9 until the portion p of the coated surface reaches just below the discharge port 7a due to the movement of the substrate W. Further, the lifting mechanism 9 moves the applicator 5 in the Z direction based on the control signal generated by the controller 12 in accordance with the timing at which the portion p of the coated surface reaches just below the discharge port 7a by the movement of the substrate W. Move up and down. The generation of the control signal and the raising / lowering of the applicator 5 in the Z direction by the raising / lowering mechanism 9 are continuously performed as the substrate W is moved.

Thereby, as will be described later, the applicator 5 is moved based on the measured value (gap value C) by the measuring means 21 in accordance with the movement of the substrate W in the direction of the arrow X1 relative to the applicator 5 for coating. The gap (gap value Cn) formed between the discharge port surface 18 and the portion of the coated surface located immediately below the discharge port surface 18 can be maintained constant by moving up and down in the Z direction. As a result, a thin film having a constant film thickness can be formed with high accuracy on the substrate W that continuously moves at a constant speed.

As shown in FIG. 4, the coated surface K of the substrate W has “swells” in the X1 direction. In FIG. 4, the waviness is shown larger than the actual one for ease of explanation (for the sake of easy understanding).

Further, as shown in FIG. 4, the coating apparatus 1 has a substrate height detector 15, and this substrate height detector 15 is a surface of the substrate W on the stage 3 (surface to be coated K). A height H (hereinafter referred to as a substrate height H) is measured with reference to the upper surface of the stage 3. The substrate height detector 15 is a non-contact type sensor, and this sensor is attached to an arm or the like extending from the gantry 4.
[Gap measurement principle and measurement method]
A specific gap measuring principle and measuring method by the measuring means 21 will be described with reference to FIGS. In addition, the execution subject of the various processes described below is the calculation unit 21b included in the measurement unit 21 unless otherwise described.

As shown in FIG. 3, the imaging means 21a is not in contact with the substrate W, and is installed so as to image the end of the reference surface 17 and the like from an oblique direction.

FIG. 5 is a perspective view showing a situation where the imaging means 21a is capturing a real image of the reference surface 17 and a reflection image of the reference surface 17 on the substrate W. FIG. 6 is an explanatory diagram of an image captured by the imaging means 21a. This image can be displayed on the monitor means 21c as a video. In each figure, the code | symbol which attached | subjected i to the end shows that it is a reflected image reflected on the to-be-coated surface K, and the code | symbol which attached | subjected d to the end represents the dimension measured in an image.

As shown in FIG. 5, the dimension of the gap formed between the reference surface 17 and the portion p of the coated surface located immediately below the reference surface 17 is the “gap value C”. The optical axis M of the imaging means 21a is inclined from the surface to be coated K of the substrate W by an angle θ.

The reflection image 17ji picked up by the image pickup means 21a is such that the end 17j is reflected on the coated surface K by the incident angle θ. Therefore, the imaging means 21a captures the end portion 17j of the reference surface 17 that is a real image and the reflected image 17ji on the coated surface K of the end portion 17j of the reference surface 17.

The edge part 17j (real image of the edge part 17j) and the reflected image 17ji imaged by the imaging means 21a can be acquired as an image as shown in FIG. This image is displayed on the monitor means 21c.

In FIG. 6, the distance Dd which is the length between the real image of the end portion 17j and the reflected image 17ji of the end portion 17j on the acquired image (the image shown on the monitor means 21c) is the end portion 17j shown in FIG. Is equal to n · D, which is obtained by multiplying the actual distance D between the image and the reflected image 17ji by the total magnification n for the image in the measuring means 21 including the imaging means 21a and the like (Dd = D · n). The total enlargement magnification n is a known value and is a value set in the calculation means 21b.

In FIG. 5, the gap value C between the reference surface 17 and the portion p of the coated surface immediately below the reference surface 17 is C = L · Sinθ and D = L · Cosφ = L · Cos ( It is calculated as C = D / (2 · Cosθ) by the relational expression of π / 2-2θ) = 2L · Sinθ · Cosθ. Here, L is the distance from the end portion 17j to the reflection image 17ji of the end portion 17j on the coated surface K.

As described above, if the distance Dd can be measured and the angle θ can be obtained on the image acquired by the imaging means 21a, the gap value C is calculated from the equation C = Dd / (2 · n · Cos θ). be able to. That is, the calculating unit 21b is configured to calculate the length (distance Dd) between the real image of the end 17j of the reference surface 17 captured by the imaging unit 21a and the reflected image 17ji of the end 17j, and the imaging unit 21a. Based on the angle θ of the optical axis M, the gap value C can be calculated.
[Method for obtaining the distance Dd and the angle θ]
The distance Dd can be obtained by image processing based on the real image of the end portion 17j and the reflected image 17ji of the end portion 17j appearing on the acquired image (monitor means 21c). There are various specific image processing methods. For example, by using the fact that the color and shade of the image change greatly, the positions of the real image of the end portion 17j and the reflected image 17ji of the end portion 17j are determined. The distance Dd between the position of the real image of the end portion 17j and the position of the reflected image 17ji can be easily obtained.

As for the angle θ, the angle of the optical axis M of the imaging means 21a may be measured, but it is difficult to measure accurately. Therefore, in the present embodiment, the angle θ is indirectly obtained from the relationship of the gap value C = Dd / (2 · n · Cos θ) by the calculation means 21b. The specific method is demonstrated using FIG.5, FIG.6, FIG.7 and FIG.

FIG. 7 is a perspective view showing a state in which the protection block 16 is raised by a predetermined amount E from the state shown in FIG. In FIG. 7, the protection block 16 and its reflection image 17ji before rising are indicated by a two-dot chain line.

7, the imaging means 21a captures the real image of the end portion 17j and the reflected image 17ji of the end portion 17j. The captured image is shown in FIG. The solid line in FIG. 8 is an image acquired in the state after the rise shown in FIG. In FIG. 8, the positions of the end portion 17j of the reference surface 17 and the reflection image 17ji of the end portion 17j before the protection block 16 is raised by the predetermined amount E are indicated by a two-dot chain line.

The end portion 17j and the reflected image 17ji indicated by the two-dot chain line are not actually displayed on the monitor means 21c, but the distance Dd between them is (before the protection block 16 is raised) ) Is stored in the calculation means 21b (internal memory of the control device 11).

In FIG. 7, the distance (shortest distance) between the end portion 17j after the protection block 16 has been raised by a predetermined amount E and the reflected image 17ji of this end portion 17j is the distance between the end portion 17j and the end portion 17j after being raised. The actual distance D1 between the reflected images 17ji is indicated. As shown in FIG. 8, the distance D1 is D1d on the acquired image (monitor unit 21c), and D1d = n · D1.

As is apparent from FIG. 7, C + E = D1d / (2.multidot.Cos.theta.), And by this formula and the formula C = Dd / (2.multidot.Cos.theta.) The amount of movement E1 of each reflected image 17ji is expressed by E1 = E · Cos θ.

Since the movement amounts E1d of the end portion 17j and the reflected image 17ji on the image (monitor means 21c) shown in FIG. 8 are expressed by E1d = n · E1, the following equation is used: E1d = (D1d−Dd) / 2 Can be sought.

That is, when the protection block 16 is raised by a predetermined amount E, the distance D1d between the end portion 17j of the acquired image (image shown on the monitor means 21c) and the reflected image 17ji of the end portion 17j, Based on the already stored distance Dd, the calculation means 21b can calculate the angle θ from the relationship Cos θ = E1 / E = (D1d−Dd) / (2 · n · E).

After the image pickup means 21a is attached to the gantry 4, the angle θ is a constant value. Therefore, in the preparation step before the actual gap value C is measured, the angle θ is obtained by the above method. It is preferable to leave.

Note that the gap value C = Dd / (2 · n · Cos θ) = a · Dd, where a = 1 / (2 · n · Cos θ) = E / (D1d−Dd) and directly obtaining θ. Instead, it is convenient and preferable to obtain the conversion coefficient a.

As described above, when the measurement unit 21 measures (calculates) the gap value C, the imaging unit 21a images another protective block 16 provided adjacent to the applicator 5 that discharges the coating liquid. As a result, the gap value C can always be measured even during coating without being affected by the coating liquid.

In the present embodiment, as shown in FIG. 4, the image pickup means 21a is provided at two locations on both ends in the Y direction, and the gap value C at each end in the Y direction is obtained from images acquired by each of the image pickup means 21a. Is calculated.

Although not shown, the imaging means 21a may take an image with the longitudinal direction (Y direction) of the protection block 16 as the optical axis direction, or may refract the optical axis using a mirror. .
[Application method]
A coating method using the coating apparatus 1 including the gap maintaining device 20 will be described. This coating method includes a process 1: a coating preparation process, a process 2: a gap measurement preparation process, a process 3: a substrate carry-in / gap confirmation process, and a process 4: a coating / substrate carry-out process. FIG. 12 is a flowchart of the coating method, showing the gap measurement preparation process to the coating start. FIG. 13 is a flowchart of the coating method, showing the operation during coating.

Step 1: Application Preparation Step The coating liquid is passed from the tank 23 (see FIG. 1) to the applicator 5 at the origin position (uppermost point), and the air contained in the flow path is removed. A coating liquid is filled in a pump 22 composed of a syringe pump, and the pump 22 and the applicator 5 are in communication with each other. By starting the pump 22, the coating liquid can be discharged from the applicator 5 (discharge port 7a), and the coating preparation process is completed.

Step 2: Gap measurement preparation step (St1 in FIG. 12)
The calculating means 21b calculates the conversion coefficient a = E / (D1d−Dd). First, the substrate W carried into the coating apparatus 1 is sucked and held on the stage 3 at the origin position. Subsequently, as shown in FIG. 9A, which is an explanatory diagram of the gap measurement preparation step, a part p (measurement target portion p) of the coated surface K of the substrate W reaches just below the substrate height detector 15. Until then, the stage 3 is moved and stopped, and the substrate height detector 15 measures the substrate height H.

Using the measured substrate height H, the controller 12 calculates the measurement preparation height coordinate Zc of the reference surface 17 from the formula Zc = Z0 + H + Cc, and stores it in the control device 11. Z0 is a Z-axis that represents the position of the reference surface 17 in the height direction when the upper surface of the stage 3 and the reference surface 17 are in contact, that is, when the upper surface of the stage 3 and the reference surface 17 are at the same height. Coordinates. In this embodiment, since the reference of the Z-axis coordinates (reference plane in the Z direction) is the upper surface of the stage, Z0 = 0. Cc is a gap value (set value) between the substrate W and the reference surface 17 and is a value stored in the control device 11.

Next, as shown in FIG. 9B, the stage 3 is moved in the direction of the arrow X <b> 1, and a part p (the measurement target portion p) of the substrate W measured for the substrate height H is the reference surface 17. Stop at the position where it reaches directly below. In response to a command from the controller 12 of the control device 11, the lifting mechanism 9 is driven, and the reference surface 17 is lowered to a position corresponding to the calculated measurement preparation height coordinate Zc to be stationary.

In this state, the imaging means 21a (see FIG. 5) captures the real image of the end portion 17j of the reference surface 17 and the reflected image 17ji of the end portion 17j, and acquires the image shown in FIG. A distance Dd, which is the distance from the edge portion 17j of the image to the reflection image 17ji of the edge portion 17j, is obtained by image processing and is stored in the control device 11.

Next, as shown in FIG. 7, the protection block 16 is raised by a predetermined amount E in the Z direction according to a command from the controller 12. After the rise, the imaging unit 21a captures the end portion 17j and the reflection image 17ji of the end portion 17j again, and acquires the image shown in FIG. A distance D1d, which is the distance from the edge portion 17j of the image to the reflected image 17ji of the edge portion 17j, is obtained by image processing and is stored in the control device 11. Subsequently, the calculation means 21b calculates the conversion coefficient a based on the equation a = E / (D1d−Dd) and stores it in the control device 11. By obtaining the conversion coefficient a necessary for calculating the gap value C in this way, the gap measurement preparation process is completed.

After completion of this step, the lifting unit including the protection block 16 and the applicator 5 and the stage 3 are returned to the origin position, and the substrate W is removed from the stage 3.

Step 3: Substrate Loading / Gap Confirmation Step In step 3, after loading the substrate W onto the stage 3 at the origin, whether or not the gap between the substrate W and the discharge port surface 18 of the applicator 5 is within the allowable range. Check and correct if the tolerance is exceeded.

First, in a state where the stage 3 is at the origin position, the substrate W is placed on the stage 3 by a substrate transport means (not shown), and the substrate W is sucked and held on the stage 3 by suction. Subsequently, as shown in FIG. 10A which is an explanatory diagram of the substrate carry-in / gap confirmation process, the stage 3 is moved and stopped until the coating start portion p0 of the substrate W reaches directly below the substrate height detector 15. Thereafter, the height H of the substrate W is measured by the substrate height detector 15.

Using the measured substrate height H, the controller 12 calculates the coating height start coordinate Zs of the discharge port surface 18 (nozzle 7a) from the formula Zs = Z0 + H + Cs + Fs, and stores it in the control device 11. Here, as described above, Z0 is the Z-axis coordinate indicating the position of the reference surface 17 in the height direction, and Z0 = 0 in the present embodiment. Cs is a set gap value between the substrate W and the discharge port surface 18 (discharge port 7a), and is input and stored in the control device 11 in advance. Fs is a dimensional difference in the Z direction between the reference surface 17 and the discharge port surface 18 (Fs> 0).

As shown in FIG. 10B, after the stage 3 is moved and stopped until the coating start part p0 reaches a position just below the reference surface 17, the lifting mechanism 9 is driven by a command from the controller 12. Then, the applicator 5 is lowered, and the height position of the discharge port surface 18 is set to a position corresponding to the calculated application height start coordinate Zs, and the applicator 5 is stopped at that position (St2 in FIG. 12).

Then, as shown in FIG. 5, the imaging means 21a captures the end portion 17j of the reference surface 17 and the reflected image 17ji of the end portion 17j (St3 in FIG. 12), and acquires the image shown in FIG. Based on this image, the calculating means 21b performs image processing to obtain a distance Dd that is the length from the end portion 17j of the reference surface 17 to the reflected image 17ji of the end portion 17j.

Using this obtained distance Dd and the conversion coefficient a already obtained and stored in the measurement preparation step, the calculation means 21b calculates the gap value C0 between the coating start part p0 and the reference surface 17 by the formula C = a · Calculated from Dd (St4 in FIG. 12).

The difference between the calculated gap value C and the sum (C + Fs) of the Z-direction dimensional difference Fs between the reference surface 17 and the discharge port surface 18 and the set gap value Cs is equal to or less than the allowable value b, that is, | (C + Fs). ) If −Cs | ≦ b, the process proceeds to the next coating step. When | (C + Fs) −Cs |> b, the correction amount h is obtained from the equation h = (C + Fs) −Cs, and the lifting mechanism 9 is driven by a command from the controller 12 to drive the protective block 16 and the applicator 5. Is lifted by a correction amount h. At this time, if h is positive, the applicator 5 is raised, and if h is negative, it is lowered. Then, again, the current (after correction) gap value C is measured in the same manner as described above, and it is confirmed that | (C + Fs) −Cs | ≦ b. After the confirmation is completed, the corrected coating height start coordinate Zs, that is, Zs = Z0 + H + Cs + Fs + h is stored (St5 in FIG. 12).

As described above, since each process is performed on the respective images of the imaging means 21a at both ends in the Y direction, for example, the substrate W is inclined along the Y direction. When the gap value C is different, the correction amount and the coating height start coordinate Zs are made different at both ends in the Y direction (St6 in FIG. 12). Thereby, it is possible to control the lifting mechanisms 9 at both ends so that the gap between the substrate W and the reference surface 17 is constant over the entire length in the Y direction.

Step 4: Application / Substrate Unloading Step The substrate W on which the application start portion p0 is located immediately below the reference surface 17 is moved at a constant speed in the direction of the arrow X1, and this application is performed as shown in FIG. The coating liquid is supplied to the applicator 5 by the coating liquid supply means 10 and the discharge of the coating liquid onto the substrate W is started at the timing when the start part p0 reaches just below the discharge port 7a. The supply flow rate of the coating liquid from the pump 22 is determined according to a preset film thickness and coating speed. The gap value between the coating start portion p0 and the discharge port 7a (discharge port surface 18) is Cn0 at the timing when the coating start portion p0 reaches just below the discharge port 7a. The gap value Cn0 is a set gap value. Same as Cs.

The substrate W continuously moves in the direction of the arrow X1 at a constant speed. During this movement, the imaging means 21a and the calculation means 21b function, and the reference surface 17 and the substrate W positioned immediately below the reference surface 17 A gap value Ci formed between the portion pi of the surface to be coated is determined every time (i = 1 to n: number of sampling). In FIG. 10C, the position in the X direction of the portion pi of each surface to be coated is expressed as Xpi (i = 1 to n) with the application start portion p0 as a base point. The position in the X direction of the application start part p0 is a position Xp0 (n = 0), and the gap value between the reference surface 17 and the application start part p0 located immediately below the reference surface 17 is C0. is there.

The calculating means 21b obtains the gap value Ci every moment, obtains the change amount Hi of the gap value Ci at each position Xpi, and sets this change amount Hi as a correction value Chi for moving the applicator 5 up and down (Hi = Chi). The correction value Chi is set in association with the position Xpi, and the set correction value Chi is transferred to the controller 12 one after another.

Then, while discharging the coating liquid from the applicator 5 to the substrate W, it is associated with the position Xpi indicating the portion pi in accordance with the timing at which the portion pi of each coated surface reaches just below the discharge port 7a. On the basis of the correction value Chi, the copying control is performed to maintain the gap between the discharge port surface 18 of the applicator 5 and the surface to be coated K, and the gap between the portion pi and the discharge port 7a (discharge port surface 18). The value Cni is constant (same as the set gap value Cs). A specific example of the copying control will be described below with reference to FIG. FIG. 11 is an explanatory diagram for explaining a specific example of the copying control. In FIG. 11, the stage 3 is omitted.

The state of FIG. 11A is a state in which the coating start part p0 located immediately below the reference surface 17 has reached directly below the discharge port 7a as the substrate W moves at a constant speed in the direction of the arrow X1. In addition, a portion p1 of the surface to be coated corresponding to the position Xp1 (n = 1) of the substrate W is located immediately below the reference surface 17. In this state, the gap value between the coating start part p0 and the discharge port 7a is Cn0. The portion p1 of the surface to be coated is higher than the coating start portion p0.

In the state of FIG. 11A, the calculation means 21b obtains the gap value C1 between the reference surface 17 and the portion p1 of the coated surface at the position Xp1 that has reached just below the reference surface 17 (FIG. 13). St11, St12). Since the gap value C1 has a change amount H1 (<0) as compared with the gap value C0, the gap value C1 is C1 = C0 + H1. The calculating means 21b obtains the change amount H1, and sets the change amount H1 as a correction value Ch1 for moving the applicator 5 up and down (H1 = Ch1, where Ch1 <0). The correction value Ch1 is information associated with the position Xp1.

When the information of the correction value Ch1 associated with the position Xp1 is transferred to the controller 12 (St13 in FIG. 13), the application surface portion p1 at this position Xp1 is matched with the timing when it reaches directly below the discharge port 7a. (State of FIG. 10B), the lifting mechanism 9 is driven to raise the applicator 5 and adjust the position of the discharge port 7a. Specifically, the discharge port 7a is raised with respect to the correction value Ch1 in accordance with the timing (St14 in FIG. 13).

For this reason, the controller 12 is based on the information including the correction value Ch1 until the portion p1 of the coated surface at the position Xp1 that has reached directly below the reference surface 17 reaches just below the discharge port 7a. Then, a control signal for raising and lowering the applicator 5 with respect to the correction value Ch1 is generated, and on the basis of this control signal, the raising and lowering mechanism 9 performs the timing at which the portion p1 of the coated surface reaches just below the discharge port 7a. The raising of the applicator 5 is completed.

In addition, below the figure which shows each state of FIG. 11 (A), (B), (C), the time chart which shows the change of the height of the applicator 5 is described. As described below in the state of FIG. 11B, when the portion p1 of the coated surface at the position Xp1 reaches directly below the discharge port 7a, the applicator 5 moves (increases with respect to the correction value Ch1). Is completed, and the control operation of the applicator 5 is prevented from being delayed.

The gap value Cn1 between the coated surface portion p1 and the discharge port 7a at the timing when the coated surface portion p1 reaches just below the discharge port 7a is a value obtained by adding the correction value Ch1 to the gap value Cn0. (Cn1 = Cn0 + Ch1). As a result, the gap value Cn1 between the ejection port surface 18 and the portion p1 of the coated surface at the position Xp1 is the same as the set gap value Cs, and coating is performed on the portion p1 of the coated surface.

In the state of FIG. 11B, the substrate W is low at the position Xp2 (n = 2). The measuring means 21 obtains a gap value C2 between the reference surface 17 and the portion p2 of the coated surface at the position Xp2 immediately below the reference surface 17 (St11, St12 in FIG. 13). Since this gap value C2 has a change amount H2 (> 0) as compared with the gap value C1, the gap value C2 is C2 = C1 + Ch1 + H2. Note that Ch1 in this equation is the previous correction value and is based on the fact that the applicator 5 has been raised before. The calculating unit 21b obtains a change amount H2 in association with the position Xp2, and sets the change amount H2 as a correction value Ch2 for moving the applicator 5 up and down (H2 = Ch2, where Ch2 <0). Information on the correction value Ch2 associated with the position Xp2 is transferred to the controller 12 (St13 in FIG. 13).

Then, in accordance with the timing at which the portion p2 of the coated surface at the position Xp2 reaches directly below the discharge port 7a (the state shown in FIG. 11C), the elevating mechanism 9 is driven to lower the applicator 5 to discharge. The height position of the outlet 7a is adjusted. Specifically, the discharge port 7a is lowered with respect to the correction value Ch2 (= change amount H2) in accordance with the timing (St14 in FIG. 13).

For this reason, the controller 12 is based on the information including the correction value Ch2 until the portion p2 of the coated surface at the position Xp2 that has reached directly below the reference surface 17 reaches just below the discharge port 7a. Then, a control signal for raising and lowering the applicator 5 with respect to the correction value Ch2 is generated, and on the basis of this control signal, the raising and lowering mechanism 9 performs the timing at which the portion p2 of the coated surface reaches just below the discharge port 7a. The raising of the applicator 5 is completed.

As described below in the state of FIG. 11C, when the portion p2 of the surface to be coated at the position Xp2 reaches just below the discharge port 7a, the applicator 5 moves (increases with respect to the correction value Ch2). Is completed, and the control operation of the applicator 5 is prevented from being delayed.

The gap value Cn2 between the portion p2 of the coated surface and the discharge port surface 18 at the timing when the portion p2 of the coated surface reaches just below the discharge port 7a is a value obtained by adding the correction value Ch2 to the gap value Cn1. (Cn2 = Cn1 + Ch2: where Ch2 <0). As a result, the gap value Cn2 between the discharge port surface 18 and the portion p2 of the coated surface at the position Xp2 is the same as the set gap value Cs, and the coating is performed on the portion p2 of the coated surface.

As described above, in the coating apparatus 1, the reference surface 17 of the protection block 16 is provided on the front side of the substrate W with respect to the discharge port 7 a, and in the coating / substrate unloading process executed by the coating apparatus 1, coating is performed. Therefore, in accordance with the movement of the substrate W relative to the applicator 5, the discharge port 7a and the portion pi of the surface to be coated of the substrate W to which the coating liquid is applied just below the discharge port 7a The coating operation by the applicator 5 is performed while executing a gap maintaining method for maintaining the gap Cni formed between the two at a constant value (set gap value Cs).

In this gap maintaining method, the gap value Ci formed between the reference surface 17 of the protection block 16 and the portion pi of the coated surface of the substrate W located immediately below the reference surface 17 is measured. When the gap value Ci is measured, the applicator 5 is based on the measured gap value Ci as the portion pi of the coated surface reaches just below the discharge port 7a by the movement of the substrate W. Is moved up and down in the Z direction so that the gap (gap value Cni) formed between the discharge port 7a and the portion pi of the coated surface is kept constant (set gap value Cs).

According to this gap maintaining method, when the gap value Ci between the reference surface 17 and the portion pi of the surface to be coated of the substrate W located immediately below the reference surface 17 is measured, the portion pi of the surface to be coated becomes The preparation time for moving the applicator 5 up and down in the Z direction can be ensured before reaching the position facing the discharge port 7a by the movement of the substrate W. For this reason, the applicator 5 is moved up and down in the Z direction in accordance with the timing at which the portion pi of the surface to be coated, which is the object of measurement, reaches the position facing the discharge port 7a. The gap value Cni with the coating surface portion pi can be kept constant (set gap value Cs). For this reason, it is possible to perform high-precision scanning control of the applicator 5 with respect to the substrate W, which was impossible in the past, and the gap can be maintained with high accuracy, so that the thickness of the coating film formed on the substrate W is uniform. Can be.

Further, in the present embodiment, as shown in the time chart shown at the bottom of the diagrams showing the states of FIGS. 11A, 11B, and 11C, the portion pi of the coated surface at the position Xpi is discharged. When it reaches directly under the outlet 7a, the movement of the applicator 5 (up and down with respect to the correction value Chi) is completed, so that the control operation of the applicator 5 is not delayed.

In order to configure such that the control is not delayed, the coating apparatus 1 performs a coating operation (coating method) including a gap maintaining method that satisfies the following condition (the following formula: Xa / V> t1 + t2 + t3). Executed.

That is, if the moving speed of the substrate W in the arrow X1 direction is V, and the horizontal distance between the end 17j of the reference surface 17 and the discharge port 7a is Xa (see FIG. 11A), it is directly below the reference surface 17. The time required for the portion pi (p1) of the coated surface to reach just below the discharge port 7a is Xa / V, and this time Xa / V is the time t1, time t2, and time defined below. It is set to be larger than the sum of t3 (Xa / V> t1 + t2 + t3). This time Xa / V is the preparation time.

Time t1: Sum of the image acquisition time by the imaging means 21a and the time (image processing time) for obtaining the gap value Ci (C1) and the correction value Chi (Ch1). Time t2: the correction value Chi (Ch1). The sum of the control signal generation processing time based on this and the communication time until the lifting mechanism 9 is operated by this control signal. Time t3: lifting and lowering after the applicator 5 starts lifting and lowering by the lifting mechanism 9 based on the control signal. Time until Completion As described above, in the present embodiment, measurement is performed while the portion pi of the coated surface that is located immediately below the reference surface 17 reaches immediately below the discharge port 7a due to the movement of the substrate W. A control signal for raising and lowering the applicator 5 in the Z direction is generated on the basis of the gap value Ci measured by the means 21, and a portion pi of the surface to be coated that is located immediately below the reference surface 17 is a substrate. W's In accordance with the timing to reach immediately below the discharge port 7a by moving, on the basis of the generated said control signal, the lifting movement of the applicator 5 according to the lifting mechanism 9 is carried out.

Therefore, when the portion pi of the surface to be coated reaches just below the discharge port 7a due to the movement of the substrate W, it is possible to complete the lifting and lowering of the applicator 5, and the control operation of the applicator 5 is delayed. Can be prevented.

As described above, according to the coating apparatus 1 of the present embodiment and the gap maintaining method performed by the coating apparatus 1, undulation occurs on the coated surface K of the substrate W, and this moves relative to the applicator 5. Even if the height of the surface to be coated K of the substrate W fluctuates, the scanning control for moving the applicator 5 up and down according to the variation amount is performed, so that the gap between the discharge port surface 18 of the applicator 5 and the substrate W is controlled. In this way, the gap formed can be kept at a constant value with high accuracy and stable coating can be performed.

Then, when the coating end portion of the substrate W reaches just below the discharge port surface 18 of the applicator 5, the application liquid supply by the coating liquid supply means 10 is stopped and the applicator 5 is raised to a predetermined position. Exit. The stage 3 continues to move even after the application is completed, and then stops.

Then, the suction of the substrate W on the stopped stage 3 is released, and the substrate W is unloaded from the stage 3 to a subsequent process by a substrate unloading means such as a robot (not shown). Thereafter, the stage 3 moves to the initial position, and the applicator 5 Moves to the top point.

The coating apparatus 1 and the gap maintaining method of the present invention are not limited to the illustrated forms, and may be other forms within the scope of the present invention. For example, the substrate W (member to be coated) is not limited to a glass substrate, and any member can be used as long as it can capture a reflected image of the discharge port 7a (discharge port surface 18) by the imaging unit 21a.

In the above embodiment, the case where the substrate W moves in the direction of the arrow X1 with respect to the applicator 5 for application has been described. However, in the present invention, the relative relationship between the substrate W and the applicator 5 is applied. The protection block 16 (reference surface 17) may be provided on the front side of application in the relative movement direction with respect to the discharge port 7a (discharge port surface 18). The “front side of application in the relative movement direction with respect to the discharge port 7 a” means that the coating liquid is not yet applied to the substrate W on the basis of the discharge port 7 a that discharges the coating liquid. It is the area side to be painted (uncoated area side).

1: coating device 2: base 3: stage 4: gantry 5: coating device 6: manifold 7a: discharge port 7: discharge flow path 8: moving mechanism 8a: linear motor 8b: guide member 9: lifting mechanism 9a: servo motor 9b: Screw shaft 9c: Nut unit 10: Coating liquid supply means 11: Controller 12: Controller 13: Lift bar 14: Reference base member 15: Substrate height detector 16: Protection block (measuring body) 17: Reference surface 17j : End portion 17ji: Reflected image 18: Discharge port surface 20: Gap maintaining device 21: Measuring means 21a: Imaging means 21b: Calculation means 21c: Monitoring means 22: Pump 23: Tank 24: Flow path 25: Gap maintaining means a: Conversion coefficients C, Ci: Gap value (reference plane) Cc: Gap value (set value) Chi: Correction value Cn, Cn i: Gap value (discharge port surface) Cs: Set gap value (discharge port surface)
D1, D1d, Dd: Distance E1, E1d: Movement amount Fs: Dimensional difference in Z direction between reference surface and discharge port surface H: Substrate height Hi: Change amount K: Surface to be coated L: Distance M: Optical axis pi , P: parts of the coated surface t1, t2, t3: time V: substrate moving speed W: substrate X1: arrow Xa: horizontal distance between the end of the reference surface and the discharge port Xpi: position Zc: reference surface Measurement preparation height coordinate Zs: coating height start coordinate θ: angle b: tolerance

Claims (8)

1. A gap formed between the coating liquid discharge port of the applicator and the portion of the coated surface of the coated member to which the coating liquid is applied facing the discharge port is defined as the coating member and the coating device. A gap maintaining method that maintains a constant according to the relative movement for coating with,
   It is formed between the reference surface of the measurement body provided on the front side of application in the relative movement direction with respect to the discharge port and the portion of the application surface of the application member facing the reference surface of the measurement body. Measure the gap,
   As the portion of the coated surface facing the reference surface of the measuring body reaches the position facing the discharge port by the relative movement, the coating device is moved to the coated surface based on the measured gap. The gap maintaining method is characterized in that the gap formed between the discharge port and the portion to be coated is kept constant by moving in a direction perpendicular to the surface.
2. Until the portion of the surface to be coated facing the reference surface of the measuring body reaches a position facing the discharge port by the relative movement, the applicator is moved to the vertical position based on the measured gap. The gap maintaining method according to claim 1, wherein a control signal for moving in a direction is generated.
3. The gap is measured by capturing a real image of an end portion of the reference surface of the measurement body and a reflection image of an end portion of the reference surface of the measurement body on the surface to be coated of the member to be coated. The gap maintaining method according to claim 1, wherein the gap maintaining method is performed based on a length between a real image of a portion and a reflected image of the end portion.
4. A measuring body having a reference surface substantially parallel to the discharge port surface including the discharge port of the coating liquid of the applicator;
   A measuring means for measuring a gap formed between a portion of the coated surface of the coated member facing the reference surface and the reference surface;
   By moving the applicator in a direction perpendicular to the surface to be applied based on the measurement value by the measurement means in accordance with the relative movement for application between the member to be applied and the applicator. A gap maintaining means for maintaining a constant gap between the exit surface and the portion of the coated surface,
   The gap maintaining device, wherein the measurement body is provided on the front side of the application in the relative movement direction with respect to the discharge port surface.
5. The gap maintaining means includes
   An elevating mechanism for moving the applicator in the vertical direction;
   The applicator is mounted on the basis of the measured value by the measuring means until the portion of the surface to be coated facing the reference surface of the measuring body reaches the position facing the discharge port by the relative movement. The gap maintenance device according to claim 4, further comprising a controller that generates a control signal for moving in the vertical direction.
6. The gap maintaining device according to claim 4 or 5, wherein the measuring body including the reference surface is integrated with the applicator.
7. The measuring means includes
   An imaging means for capturing a real image of an end portion of the reference surface of the measurement body and a reflection image of an end portion of the reference surface of the measurement body on the surface to be coated of the member to be coated;
   The calculation means for calculating the gap based on a length between the captured real image of the end portion and the reflected image of the end portion, further comprising: The gap maintaining device as described.
8. An applicator having a discharge port for discharging a coating liquid onto a member to be coated;
   A coating liquid supply means for supplying a coating liquid to the applicator;
   A moving mechanism for relatively moving the applicator and the member to be coated in a direction parallel to the surface to be coated of the member to be coated for coating;
   And a gap maintaining device according to any one of claims 4 to 7.

Images