KR101074666B1 - Paste dispenser and method for applying paste - Google Patents

Abstract

The paste dispenser and paste application method according to the present invention is configured to adjust the position of the laser displacement sensor with respect to the nozzle, and by adjusting the position of the imaging point of the laser displacement sensor so as to be within the region where the laser does not interfere, There is an effect that can accurately measure the interval between.

Substrate, Paste, Coating

Description

Paste dispenser and paste application method {PASTE DISPENSER AND METHOD FOR APPLYING PASTE}

The present invention relates to a paste dispenser and paste application method for applying paste onto a substrate.

In general, a flat panel display (FPD) is an image display device that is thinner and lighter than a television or a monitor employing a CRT. As flat panel displays, Liquid Crystal Display (LCD), Plasma Display Panel (PDP), Field Emission Display (FED), Organic Light Emitting Diodes (OLED), etc. It is used.

Among them, the liquid crystal display is a display device in which a desired image is displayed by individually supplying data signals according to image information to liquid crystal cells arranged in a matrix to adjust light transmittance of the liquid crystal cells. Liquid crystal displays are widely used because of their thinness, light weight, low power consumption and low operating voltage. The manufacturing method of the liquid crystal panel generally employed in such a liquid crystal display will be described.

First, a color filter and a common electrode are formed on an upper substrate, and a thin film transistor (TFT) and a pixel electrode are formed on a lower substrate facing the upper substrate. Subsequently, after the alignment films are applied to the substrates, the alignment films are rubbed to provide a pre-tilt angle and an orientation direction to the liquid crystal molecules in the liquid crystal layer to be formed therebetween.

Then, the paste is applied to at least one substrate in a predetermined pattern to form a paste pattern so as to maintain a gap between the substrates and to prevent the liquid crystal from leaking to the outside and to seal the gaps between the substrates. Through the process of forming a liquid crystal layer in the liquid crystal panel is manufactured.

In the manufacture of such a liquid crystal panel, a device called a paste dispenser is used to form a paste pattern on a substrate. The paste dispenser includes a stage on which a substrate is mounted, a head unit equipped with a nozzle through which paste is discharged, and a head support for supporting the head unit.

Such a paste dispenser forms a paste pattern on a substrate while varying the relative position of each nozzle and the substrate. That is, the paste dispenser moves the nozzles mounted on each head unit in the Z-axis direction up and down to control the gap between the nozzle and the substrate while controlling the nozzle and / or the substrate in the X-axis direction and the Y-axis direction. It moves horizontally and discharges a paste from a nozzle on a board | substrate, and forms a paste pattern.

In the process of forming a paste pattern on the substrate as described above, in order to constantly control the gap between the nozzle and the substrate, each head unit is equipped with a laser displacement sensor. The laser displacement sensor provides gap data measuring the gap between the nozzle and the substrate to the controller of the dispenser, thereby allowing the controller to constantly control the gap between the nozzle and the substrate based on the gap data. That is, in the process of forming the paste pattern while horizontally moving at least one of the nozzle and the substrate in the X-axis direction and the Y-axis direction, if the gap between the nozzle and the substrate changes due to uneven or other causes, the paste After the pattern is formed, a paste pattern defect may occur in which the width and height of the paste pattern are out of a set range. To avoid this problem, the paste dispenser is equipped with a laser displacement sensor.

The laser displacement sensor includes a light emitting unit for emitting a laser, and a light receiving unit for receiving a laser that is emitted from the light emitting unit and reflected on the substrate. It serves to measure the gap between the substrate and the nozzle by outputting.

Meanwhile, in the process of manufacturing the liquid crystal panel, an alignment layer may be coated on the substrate, and the paste may be applied on the top surface of the alignment layer or a boundary line where the alignment layer and the substrate meet. In this case, an imaging point, which is a point at which the laser light emitted from the laser displacement sensor is reflected, may be positioned on the upper surface and the boundary line of the alignment layer. In this case, a phenomenon may occur in which the laser light emitted from the laser displacement sensor interferes with the alignment film. In addition, a plurality of paste patterns may be formed on the substrate. When the gaps between the paste patterns are narrow, an imaging point of the laser that emits light from the laser displacement sensor may be positioned on adjacent paste patterns. In this case, a phenomenon may occur in which the laser light emitted from the laser displacement sensor interferes with an adjacent paste pattern. As described above, when the laser that emits light from the laser displacement sensor interferes with the alignment layer or the adjacent paste pattern, the gap measurement between the substrate and the nozzle cannot be performed smoothly. Since the gap between them is not accurately adjusted, a paste pattern defect may occur in which the width and height of the paste pattern are out of a set range.

On the other hand, in the case of the conventional paste dispenser, since the configuration in which the laser displacement sensor is fixed to the position adjacent to the nozzle is applied, there is a problem in that it cannot cope with the phenomenon of interference of the laser by the alignment film as described above. In particular, when the spacing between the paste patterns is narrow, since the laser interferes with the adjacent paste patterns, there is a problem in that there is a limit in reducing the spacing between the paste patterns below a predetermined interval.

The present invention is to solve the above problems of the prior art, an object of the present invention is configured to adjust the position of the laser displacement sensor with respect to the nozzle, the area where the laser does not interfere the position of the imaging point of the laser displacement sensor The present invention provides a paste dispenser and a paste coating method that can improve the quality of a paste pattern by accurately measuring the distance between the substrate and the nozzle by adjusting the inside of the nozzle.

The paste dispenser according to the present invention for achieving the above object is provided with a nozzle for discharging the paste, a light emitting portion for emitting a laser and a laser light emitted from the light emitting portion and reflected on the substrate It may be configured to include a laser displacement sensor consisting of a light receiving unit for receiving, a sensor moving device for adjusting the position of the laser displacement sensor relative to the nozzle, and a control unit for controlling the sensor moving device.

Here, the sensor moving device includes a first member on which the laser displacement sensor is supported, a second member on which the first member is slidably installed in the first direction, and a second direction on which the second member is perpendicular to the first direction. It may be configured to include a third member that is slidably installed.

On the other hand, between the first member and the second member is connected to the first member is provided with a first driving unit for moving the first member in the first direction, between the second member and the third member is connected to the second member A second driving part for moving the two members in the second direction may be installed.

Here, it is preferable that a 1st drive part and a 2nd drive part consist of a linear motor.

Meanwhile, the controller may control the sensor moving device according to the information of the paste pattern to be formed on the substrate to relatively move the laser displacement sensor with respect to the nozzle.

In addition, the paste coating method according to the present invention for achieving the above object, in the paste coating method for forming a plurality of paste patterns on the substrate, (a) forming at least one paste pattern on the substrate And (b) applying the paste adjacent to the paste pattern formed in step (a), wherein the imaging point of the laser emitted from the laser displacement sensor measuring the gap between the substrate and the nozzle is formed in step (a). The method may include forming a paste pattern at a position not overlapping with the paste pattern formed in the step (a) while moving the laser displacement sensor with respect to the nozzle so as not to be positioned on the pattern.

Here, the step (a) may be to form a paste pattern on the substrate according to the information of the preset paste pattern, the step (b) may be a paste pattern on the substrate in accordance with the information of the preset paste pattern The laser displacement sensor may be relatively moved with respect to the nozzle in accordance with the information of the preset paste pattern.

Also, the step (b) may be performed to move the laser displacement sensor with respect to the nozzle so that the imaging point of the laser displacement sensor is positioned at a position where the alignment layer on the substrate is not applied. It is desirable to prevent the laser from interfering with the alignment film.

In addition, the paste coating method according to the present invention for achieving the above object, (a) scanning the substrate before applying the paste on the substrate, and (b) information of the substrate scanned in the step (a) A laser displacement sensor for measuring a gap between the substrate and the nozzle in a region where the alignment layer is coated on the substrate, and (c) an alignment layer on the substrate measured in the step (b) And forming a paste pattern on the substrate while moving the laser displacement sensor with respect to the nozzle so that the imaging point of the laser emitted from the laser beam is not positioned.

The paste dispenser according to the present invention is configured to adjust the position of the laser displacement sensor with respect to the nozzle, and by adjusting the position of the imaging point of the laser displacement sensor so as to be within the region where the laser does not interfere, the gap between the substrate and the nozzle is accurately measured. It can work.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the paste dispenser according to the present invention will be described.

As shown in Figs. 1 to 4, the paste dispenser according to the present invention includes a frame 10, a stage 20 provided on the frame 10, on which a substrate S is mounted, and both sides of the stage. A pair of support movement guides 30 are installed and extended in the Y-axis direction, and both ends are supported by a pair of support movement guides 30 so that the head support is installed on the stage 20 and extends in the X-axis direction. 40, a head unit 50 mounted on the head support 40 so as to be movable in the X-axis direction, and equipped with a nozzle 53 and a laser displacement sensor 54 for discharging paste, and controlling a paste coating operation. It may be configured to include a control unit 80.

On the frame 10, an X-axis moving device 21 for moving the stage 20 in the X-axis direction may be installed, and a Y-axis moving device 22 for moving the stage 20 in the Y-axis direction is installed. Can be. That is, the Y-axis guide 221 of the Y-axis moving device 22 is installed on the frame 10, and the X-axis guide 211 of the X-axis moving device 21 is installed above the Y-axis moving device 22. The stage 20 may be seated on the X-axis guide 211. By such a configuration, the stage 20 may be guided by the X-axis guide 211 and moved in the X-axis direction, and the X-axis guide 211 is guided and moved by the Y-axis guide 221 to the Y-axis. Can be moved in a direction. On the other hand, the present invention is not limited to the configuration that the Y-axis guide 221 is installed on the upper portion of the frame 10 and the X-axis guide 211 is seated on the upper portion of the Y-axis guide 221, the frame 10 The X-axis guide 211 is installed on the upper portion and the configuration that the Y-axis guide 221 is seated on the upper portion of the X-axis guide 211 may be applied. Of course, only one of the X-axis moving device 21 and the X-axis guide 211 and the Y-axis moving device 22 and the Y-axis guide 221 is applied, so that the stage is in the X-axis direction and the Y-axis direction. A configuration that moves only in either direction can be applied.

Both ends of the head support 40 may be installed with a support for moving the support 41 is connected to the support guide movement guide (30). By the interaction of the support movement guide 30 and the support movement device 41, the head support 40 can be moved in the longitudinal direction of the support movement guide 30, that is, the Y-axis direction. Accordingly, the head unit 50 may be moved in the Y-axis direction by the movement of the head support 40 in the Y-axis direction.

The head support guide 40 may be installed in the head support 40 in the X-axis direction, and the head mover 51 may be connected to the head support guide 42 of the head support 40 in the head unit 50. ) Can be installed. By the interaction of the head moving guide 42 and the head moving device 51, the head unit 50 can be moved in the longitudinal direction of the head support 40, that is, the X axis direction.

As shown in FIG. 2, the head unit 50 is disposed adjacent to the syringe 52 in which the paste is filled, the nozzle 53 in communication with the syringe 52, and the paste is discharged. To position the laser displacement sensor 54 to measure the gap data between the nozzle 53 and the substrate S and to position the laser displacement sensor 54 relative to the nozzle 53. It may be configured to include a sensor moving device 70 for moving the displacement sensor 54 separately.

The laser displacement sensor 54 is composed of a light emitting unit 541 for emitting a laser, and a light receiving unit 542 spaced apart from the light emitting unit 541 at a predetermined interval and receiving a laser beam reflected from the substrate S. Outputs an electrical signal according to the imaging position of the laser emitted from the unit 541 to the control unit 80 to measure the gap data between the substrate S and the nozzle 53. .

As shown in FIG. 3, the sensor moving device 70 includes a first member 71 on which the laser displacement sensor 54 is supported, and a first member 71 slidably installed in the Y-axis direction. The second member 72 and the second member 72 may be configured to include a third member 73 slidably installed in the X-axis direction perpendicular to the Y-axis direction. Accordingly, the laser displacement sensor 54 moves in the Y-axis direction based on the second member 72 of the first member 71 and based on the third member 73 of the second member 72. By the movement in the X-axis direction, it can be moved in the Y-axis direction and the X-axis direction. In addition, a Y-axis driving part 81 may be installed between the first member 71 and the second member 72 to connect the first member 71 to move the first member 71 in the Y-axis direction. The X-axis driving unit 82 may be installed between the second member 72 and the third member 73 to connect the second member 72 to move the second member 72 in the X-axis direction. Accordingly, the laser displacement sensor 54 may be moved in the Y-axis direction by the Y-axis movement of the first member 71 by the operation of the Y-axis driver 81, and the laser displacement sensor ( 54 may be moved in the X-axis direction by the X-axis movement of the second member 72 by the operation of the X-axis driving unit 82. The movement of the laser displacement sensor 54 may be controlled by the controller 80 in the process of applying the paste on the substrate (S).

Here, the Y-axis driving unit 81 and the X-axis driving unit 82 is preferably composed of a linear motor for the stable movement of the first member 71 and the second member 72. That is, the Y-axis driving unit 81 is a linear motor 811 disposed to extend in the Y-axis direction on the first member 71 and an LM guide 812 disposed to extend in the Y-axis direction on the second member 72. It may be configured to include, the X-axis driving portion 82 is disposed to extend in the X-axis direction to the linear motor 821 and the third member (73) disposed to extend in the X-axis direction on the second member (72). It may be configured to include a LM guide 822. On the other hand, the present invention, as described above, the Y-axis drive unit 81 and the X-axis drive unit 82 is not limited to being composed of a linear motor, the Y-axis drive unit 81 and the X-axis drive unit 82 is a ball screw Or a configuration in which a piezoelectric element or the like is provided.

5 illustrates another example of the sensor moving device 70 shown in FIG. 3, and the configuration shown in FIG. 5 includes the configuration shown in FIG. 3 and the first member 71 and the second member 72. The slide movement direction is different, and the installation positions of the X-axis driving portion 82 and the Y-axis driving portion 81 are different. That is, as shown in FIG. 5, the sensor moving device 70 includes a first member 71 on which the laser displacement sensor 54 is supported, and a first member 71 slidably installed in the X-axis direction. It may be configured to include a second member 72, and a third member 73 is slidably installed in the Y-axis direction perpendicular to the X-axis direction. Accordingly, the laser displacement sensor 54 moves in the X-axis direction based on the second member 72 of the first member 71 and based on the third member 73 of the second member 72. By the movement in the Y-axis direction, it can be moved in the X-axis direction and Y-axis direction. In addition, an X-axis driving part 82 may be installed between the first member 71 and the second member 72 to connect the first member 71 to move the first member 71 in the X-axis direction. The Y-axis driving unit 81 may be installed between the second member 72 and the third member 73 to connect the second member 72 to move the second member 72 in the Y-axis direction. Accordingly, the laser displacement sensor 54 may be moved in the X-axis direction by the X-axis movement of the first member 71 by the operation of the X-axis driving unit 82, and the laser displacement sensor ( 54 may be moved in the Y-axis direction by the Y-axis movement of the second member 72 by the operation of the Y-axis drive unit 81. The movement of the laser displacement sensor 54 may be controlled by the control unit 80 in the process of applying the paste on the substrate (S).

6 shows another example of the head unit of the paste dispenser according to the present invention, in which the syringe 52 is arranged to be spaced apart from the laser displacement sensor 54 at predetermined intervals in the Y-axis direction, and the nozzle 53 is laser. Located between the light emitting portion 541 and the light receiving portion 542 of the displacement sensor 54, and extends approximately in the Y-axis direction between the syringe 52 and the nozzle 53, the syringe 52 and the nozzle 53 Presents the head unit 50 is provided with a connection pipe 55 for connecting.

The head unit 50 having the shape shown in FIG. 6 is also provided with the sensor moving device 70 shown in FIGS. 3 and 5, and the laser displacement sensor 54 moves in the X-axis direction and the Y-axis direction. Can be.

As shown in FIG. 7, by the configuration as described above, the position of the imaging point 545, which is a point at which the laser is reflected on the substrate S by being emitted from the laser displacement sensor 54, is determined by the position of the nozzle 53. The area around the position of the discharge port 535 can be adjusted.

Hereinafter, the operation of the paste dispenser according to the present invention will be described with reference to FIGS. 8 to 10. 8 to 10 are schematic views illustrating a state in which the paste pattern P2 is formed in a position where the paste pattern P1 already formed on the substrate S does not overlap while maintaining a narrow gap therebetween.

As shown in FIG. 8, when the paste pattern P2 is formed at a position adjacent to the already formed paste pattern P1, the paste pattern P2 in which the imaging point 545 of the laser displacement sensor 54 is already formed. ) May be located on the In this case, since the laser emitted from the light emitting portion 541 of the laser displacement sensor 54 is not properly reflected on the upper surface of the substrate S, it may interfere with the already formed paste pattern P1, so that the laser displacement The gap measurement between the substrate S and the nozzle 53 using the sensor 54 may not be performed smoothly.

Therefore, as shown in FIG. 9, the laser displacement sensor 54 is moved from the nozzle 53 so that the imaging point 545 of the laser displacement sensor 54 is moved to a position not overlapping with the already formed paste pattern P1. Move in the X-axis direction or the Y-axis direction. Accordingly, the paste pattern P2 is formed on the substrate in a state where the laser is prevented from interfering with the already formed paste pattern P1. In this case, the movement of the laser displacement sensor 54 may be performed by the operations of the X-axis driver 82 and the Y-axis driver 81 under the control of the controller 80.

Therefore, as shown in FIG. 10, when the paste pattern P2 is formed at a position adjacent to the already formed paste pattern P1, the imaging point 545 of the laser displacement sensor 54 is formed by the nozzle 53. It may be located in a region that does not overlap with the paste pattern P1 already formed around the discharge port 535. Accordingly, since the laser light emitted from the light emitting part 545 of the laser displacement sensor 54 does not interfere with the already formed paste pattern P1, the substrate S using the laser displacement sensor 54 and the nozzle 53 are interposed therebetween. The gap measurement of can be performed accurately. In addition, the spacing between the paste patterns P1 and P2 may be minimized as compared with the related art. Here, when the laser displacement sensor 54 is moved relative to the nozzle 53 so that the imaging point 545 of the laser displacement sensor 54 is not positioned on the already formed paste pattern P1, the laser displacement sensor 54 It is preferable to prevent the laser from interfering with the alignment film so that the position of the imaging point 545 of the laser after the movement of N) is located in a region where the alignment film is not applied on the substrate S.

Meanwhile, when forming a plurality of paste patterns P1 and P2 adjacent to each other, as shown in FIG. 11, the information of the plurality of paste patterns P1 and P2 to be formed on the substrate S is previewed in advance. The paste is applied onto the substrate S according to the information of the set paste patterns P1 and P2 (S2), and on the paste pattern P1 on which the imaging point 545 of the laser is already formed. Paste set at a position not overlapping with the already formed paste pattern P1 while relatively moving the laser displacement sensor 54 with respect to the nozzle 53 according to the information of the paste patterns P1 and P2 so as not to be positioned. The paste pattern P2 may be formed according to the information of the pattern P2 (S4).

In this way, the plurality of paste patterns P1 and P2 adjacent to each other are formed while relatively moving the laser displacement sensor 54 with respect to the nozzle 53 in accordance with the information of the paste patterns P1 and P2 set in advance. Therefore, the movement of the laser displacement sensor 54 can be minimized, and the movement position of the laser displacement sensor 54 can be predicted.

On the other hand, the movement of the laser displacement sensor 54 with respect to the nozzle 53, as described above, when forming the paste patterns (P1) (P2) having a narrow gap, the laser that emits light from the laser displacement sensor 54 Not only can be used for the purpose of preventing interference with the already formed paste pattern P1. The laser light emitted from the laser displacement sensor 54 in the process of forming the paste pattern may also be used when there is a possibility of interference by the alignment film. That is, in order to prevent the laser light emitted from the laser displacement sensor 54 from interfering with the alignment film applied on the substrate S, an imaging point of the laser may be located in an area where the alignment film is not applied on the substrate S. The laser displacement sensor 54 can be moved with respect to the nozzle 53.

This process, as shown in Figure 12, the step (S10) of scanning the entire substrate S before applying the paste on the substrate (S), the substrate S from the information of the scanned substrate (S) Measuring the coating area coated with the alignment film on the step (S20), and the laser displacement sensor 54 to the nozzle 53 so that the imaging point 545 of the laser displacement sensor 54 is not positioned in the measured coating area of the alignment film. It can be made in the step (S30) of applying a paste while moving horizontally. Accordingly, since the laser light emitted from the light emitting unit 541 of the laser displacement sensor 54 does not interfere with the alignment layer in the process of applying the paste on the substrate S, the substrate S using the laser displacement sensor 54. And gap measurement between the nozzle 53 can be performed accurately. Here, a camera or a laser scanner or the like may be used to scan the entirety of the substrate S to obtain information of the substrate S, and the information of the scanned substrate S may be related to the captured image or the laser reflectance. Waveforms and the like.

In the paste dispenser and the paste coating method according to the present invention as described above, the laser light emitted from the light emitting part 545 of the laser displacement sensor 54 is interfered by the paste pattern P1 or the alignment film already formed on the substrate S. Since the paste pattern can be formed on the substrate S while moving the laser displacement sensor 54 with respect to the nozzle 53 so as not to prevent the defect, the paste pattern can be accurately measured to prevent the paste pattern from being defective. It can be effective.

The technical idea described in each embodiment of the present invention may be implemented independently, or may be implemented in combination with each other. In addition, the present invention has been described through the embodiments described in the drawings and detailed description of the invention, which is merely exemplary, and those skilled in the art to which the present invention pertains various modifications and equivalent other embodiments from this It is possible. Accordingly, the technical scope of the present invention should be determined by the appended claims.

1 is a perspective view showing a paste dispenser according to the present invention.

2 is a perspective view showing a part of the head unit of the paste dispenser according to the present invention.

3 is an exploded perspective view of the head unit of FIG. 2.

4 is a control block diagram of a paste dispenser according to the present invention.

5 is an exploded perspective view showing another example of the head unit of FIG. 3.

6 is a perspective view showing another example of the head unit of the paste dispenser according to the present invention.

Figure 7 is a schematic diagram showing the position of the discharge port of the nozzle in the paste dispenser according to the present invention and the position of the imaging point of the laser emitted from the laser displacement sensor.

8 and 9 are operational state diagrams of the paste dispenser according to the present invention.

FIG. 10 is a schematic diagram showing the positions of the ejection openings of the nozzles and the positions of the imaging points of the lasers emitted by the laser displacement sensor in the cases of FIGS. 8 and 9.

11 is a flowchart showing another example of a paste coating method according to the present invention.

12 is a flowchart showing another example of a paste coating method according to the present invention.

*** Explanation of symbols for main parts of drawing ***

50: head unit 53: nozzle

54: laser displacement sensor 535: discharge port

545: imaging point S: substrate

Claims (9)

A nozzle through which paste is discharged; A laser displacement sensor provided at a position adjacent to the nozzle, the laser displacement sensor including a light emitting unit for emitting a laser and a light receiving unit for receiving a laser emitted from the light emitting unit and reflected on a substrate; A sensor moving device for adjusting the position of the laser displacement sensor with respect to the nozzle; And And a control unit for controlling the sensor moving device to move the laser displacement sensor so that the imaging point of the laser emitted from the laser displacement sensor does not overlap with the paste pattern formed on the substrate. Paste dispenser. A nozzle through which paste is discharged; A laser displacement sensor provided at a position adjacent to the nozzle, the laser displacement sensor including a light emitting unit for emitting a laser and a light receiving unit for receiving a laser emitted from the light emitting unit and reflected on a substrate; A sensor moving device for adjusting the position of the laser displacement sensor with respect to the nozzle; And Paste dispenser comprising a head unit including a control unit for controlling the sensor moving device for moving the laser displacement sensor so that the imaging point of the laser emitted from the laser displacement sensor is moved to a position where the alignment film on the substrate is not applied . The method according to claim 1 or 2, The sensor moving device, A first member on which the laser displacement sensor is supported; A second member in which the first member is slidably installed in a first direction; And And a third member in which the second member is slidably installed in a second direction perpendicular to the first direction. The method of claim 3, A first driving part is installed between the first member and the second member to connect the first member to move the first member in the first direction. And a second driving part connected to the second member to move the second member in the second direction between the second member and the third member. 5. The method of claim 4, The first dispenser and the second drive portion paste dispenser, characterized in that composed of a linear motor. In a paste coating method of forming a plurality of paste patterns on a substrate, (a) forming at least one paste pattern on the substrate; And (b) moving the laser displacement sensor with respect to the nozzle such that the imaging point of the laser emitted from the laser displacement sensor for measuring the gap between the substrate and the nozzle is not located on the paste pattern formed in step (a); A paste applying method comprising the step of forming a paste pattern in a position that does not overlap with the paste pattern formed in step a). The method of claim 6, In the step (a), the paste pattern is formed on the substrate according to the preset paste pattern information. In the step (b), the paste pattern is formed on the substrate according to the preset paste pattern information, and the laser displacement sensor is moved with respect to the nozzle according to the preset paste pattern information. . 8. The method according to claim 6 or 7, In the step (b), the laser displacement sensor is moved with respect to the nozzle so that the imaging point of the laser displacement sensor is positioned at a position where the alignment film on the substrate is not applied. (a) scanning the substrate before applying the paste on the substrate; (b) measuring a region where an alignment film is applied on the substrate from the information of the substrate scanned in step (a); And (c) the laser with respect to the nozzle so that the imaging point of the laser emitted from the laser displacement sensor for measuring the gap between the substrate and the nozzle is not located in the area where the alignment film is coated on the substrate measured in step (b). Forming a paste pattern on the substrate while moving the displacement sensor.

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