KR100919622B1 - Distance sensor of paste dispenser - Google Patents

Abstract

The present invention discloses a distance sensor of a paste dispenser. According to the present invention, in a paste dispenser for applying paste on a substrate while changing the application position of the nozzle, by forming two measurement points on the substrate, the measurement points are before and after the application position on the basis of the horizontal movement direction of the application position. A light emitting unit for projecting light so as to be positioned at both sides and positioned at both sides of the application position; And a light receiving unit receiving the light reflected from the measurement points and converting the light into an electrical signal.

Description

Distance sensor of paste dispenser

The present invention relates to a paste dispenser, and more particularly to a distance sensor for measuring the distance between the substrate and the nozzle in the paste dispenser.

The paste dispenser is a device for applying paste in a predetermined pattern on one substrate in order to bond or seal two substrates in the process of manufacturing a flat panel display. The paste dispenser includes a stage on which the substrate is seated and a nozzle through which the paste is discharged. The nozzle is located above the stage.

The paste dispenser applies paste onto the substrate while changing the position of the nozzle relative to the substrate so that a paste pattern of a predetermined shape is formed. In this case, the substrate and / or the nozzle moves in the horizontal direction to change the horizontal position of the nozzle relative to the substrate, and the nozzle moves in the vertical direction to change the height of the nozzle.

As described above, when the paste pattern is formed, the height of the nozzle may not be controlled as set due to the flatness error of the substrate. A distance sensor is provided next to the nozzle so that the height of the nozzle is controlled as set. The distance sensor measures the actual distance between the substrate and the nozzle and provides the control to the paste dispenser. The controller controls the height of the nozzle based on the actual distance data provided.

As shown in FIG. 1, the measurement point 1 of the distance sensor is located on the front right side of the coating position 2 based on the horizontal movement of the nozzle application position 2 on the substrate S along the direction of the arrow. Can be located. In this case, when the paste is applied on the substrate S in a clockwise direction in a closed loop, the measuring point 1 and the application position 2 are moved along the path as shown in FIG. do.

However, in the above example, the following problem occurs. In FIG. 2, the left side of the substrate S is defined as the front and the right side is defined as the rear. Then, in the process of the application | coating position 2 bends in the back right of the board | substrate S, and moves to the left side, the measuring point 1 moves across the already apply | coated paste.

As a result, while the measurement point 1 passes over the coated paste, the value measured by the distance sensor is not the distance value between the substrate and the nozzle, but the distance value between the applied paste and the nozzle. That is, the value measured while passing over the paste to which the measuring point 1 is applied becomes a distorted value.

If the distorted value is used as it is to control the height of the nozzle, a defect may occur in a portion of the paste pattern in which the width and height values deviate from the set range.

In addition, it is assumed that the distance sensor is set to have a measurement allowance that is a little wider than the flatness error range of the substrate. Then, while the measuring point 1 passes over the applied paste, there may be values out of the measurement allowance among the values measured by the distance sensor. Accordingly, an error may occur when controlling the height of the nozzle.

In order to solve this problem, when controlling the height of the nozzle, the distance data between the applied paste and the nozzle may be excluded. However, the height of the nozzle may not be controlled as set in the excluded distance data section.

Also, referring to FIG. 2, while the application position 2 moves along the left line and the front line of the substrate S, the measurement point 1 is in a position ahead of the application position 2. Accordingly, the distance between the substrate and the nozzle is measured in advance while the measuring point 1 moves earlier, and the paste is applied later, while the application position 2 moves subsequently. Therefore, based on the distance data measured in advance, the height of the nozzle at the position where the paste is to be applied can be controlled.

However, while the application position 2 moves along the right line and the rear line of the substrate S, the measuring point 1 is in a position behind the application position 2. Accordingly, the paste is applied in advance while the application position 2 moves earlier, and the distance between the substrate and the nozzle is inevitably measured later while the measurement point 1 moves subsequently. That is, the distance data cannot be measured in advance at the position where the paste is to be applied. Therefore, the height of the nozzle at the position where the paste is to be applied may be difficult to be controlled as set.

An object of the present invention is to solve the above problems, the distance between the substrate and the nozzle can be measured without distortion over the entire process of forming the paste pattern, the distance between the substrate and the nozzle at the position where the paste is to be applied It is to provide a distance sensor of the paste dispenser capable of measuring in advance.

The distance sensor of the paste dispenser according to the present invention for achieving the above object is a paste dispenser for applying a paste on a substrate while changing the application position of the nozzle, by forming two measuring points on the substrate, A light emitting unit which projects light so as to be positioned in front and rear of the coating position with respect to the horizontal movement direction of the coating position, and positioned at both sides with the coating position in the center; And a light receiving unit receiving light reflected from the measurement points and converting the light into an electrical signal.

According to the present invention, during the entire process of forming the paste pattern, any one of the measuring points can always be located before the application position, so that the height of the nozzle at the position where the paste is to be applied is controlled based on the previously measured distance data. Can be.

In addition, according to the present invention, since the distance data measured while passing the measuring point on the applied paste can be excluded, the distance between the substrate and the nozzle can be measured without distortion. Therefore, the paste pattern may be formed so that the width and height do not deviate from the set range.

Further, according to the present invention, since the distance data outside the measurement allowable range may be excluded, an error due to a value outside the measurement allowable range may not occur when the height of the nozzle is controlled.

1 is a plan view showing an example of the positional relationship between a coating position and a measuring point in the conventional distance sensor.

FIG. 2 is a plan view illustrating an example of a movement path of an application position and a measurement point illustrated in FIG. 1.

3 is a perspective view illustrating an example of a paste dispenser to which a distance sensor according to an embodiment of the present invention is applied.

4 is a perspective view of the head unit of FIG. 3;

5 is a block diagram of a distance sensor according to an embodiment of the present invention.

FIG. 6 is a plan view illustrating an example of a positional relationship between an application position and measurement points in the distance sensor illustrated in FIG. 5.

7 is a plan view illustrating an example of a movement path of an application position and measurement points illustrated in FIG. 6.

8 is a block diagram of a distance sensor according to another embodiment of the present invention.

<Brief description of the major symbols in the drawings>

1,116,117 Measuring point 2,30 Application point

22..Nozzle 100,200..Distance sensor

110,210..Light emitting part 120,220..Light receiving part

130,230..Signal processing part P..Pattern pattern

S..substrate

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view illustrating an example of a paste dispenser to which a distance sensor according to an embodiment of the present invention is applied.

As shown in FIG. 3, the paste dispenser 10 includes a frame 11, a stage 12, a head support 13, a head unit 21, and a controller (not shown). The stage 12 is disposed above the frame 11. The stage 12 is formed to seat the substrate S supplied from one side of the frame 11. The stage 12 may be fixed to the frame 11 or may slide in the Y-axis direction by a stage Y-axis actuator. The stage 12 can also slide in the X-axis direction by the stage X-axis actuator.

The head support 13 is disposed above the stage 12. The head support 13 is formed to extend in the X-axis direction, both ends are supported by the frame 11. The head support 13 can slide in the Y-axis direction by the Y-axis actuator for the head support.

The head unit 21 is supported by the head support 13 so that a movement along the X-axis direction is possible. The head unit 21 can slide in the X-axis direction by the actuator for the head unit. The head unit 21 may be configured as shown in FIG.

The head unit 21 shown in FIG. 4 includes a nozzle 22 through which paste is discharged, and an application head 23 supporting the nozzle 22. The nozzle 22 is connected to a syringe 24 containing paste. The application head 23 can be elevated by the Z-axis actuator to adjust the height of the nozzle 22.

The Z-axis actuator may include a Z-axis motor 25 and a lifting unit (not shown) that is lifted and lowered by the Z-axis motor 25. Here, the lifting part may be fixed to the application head 23. When the lifting unit is lifted by the Z-axis motor 25, the application head 23 fixed to the lifting unit can be lifted. When the application head 23 is elevated, the height of the nozzle 22 can be adjusted.

The control unit controls the actuators such that the nozzle 22 moves in the X-axis, Y-axis, and Z-axis directions with respect to the substrate S. FIG. And the control part controls so that the paste may be discharged from the nozzle 22 in the set amount. Therefore, the controller can apply the paste onto the substrate S while changing the application position of the nozzle 22 with respect to the substrate S, thereby forming the paste pattern P as shown in FIG. 4.

In the process of forming the paste pattern P by the controller, the height of the nozzle 22 may not be controlled as set due to the flatness error of the substrate S. FIG. In order to control the height of the nozzle 22 as set, a distance sensor 100 according to an embodiment of the present invention is provided next to the nozzle 22.

The distance sensor 100 is for measuring the actual distance between the substrate S and the nozzle 22. The distance sensor 100 provides the measured actual distance data to the controller so that the controller receiving the actual distance data controls the height of the nozzle 22.

5 is a configuration diagram of a distance sensor according to an embodiment of the present invention.

As shown in FIG. 5, the distance sensor 100 includes a light emitting unit 110 and a light receiving unit 120. The light emitter 110 projects light to form two measurement points 116 and 117 on the substrate S. FIG. The light emitting unit 110 includes a light source 111 and a light splitter 112. The light source 111 is configured to project one light. As the light source 111, a laser light source capable of projecting laser light may be used.

The light splitter 112 splits the light projected from the light source 111 into two lights to be incident on the substrate S. Light incident on the substrate S forms two measurement points 116 and 117 on the substrate S. FIG. The light splitter 112 includes a transflective film 112a and a total reflection film 112b. Here, the semi-transmissive film 112a is disposed closer to the light source 111 than the total reflection film 112b.

The light projected from the light source 111 is partially transmitted through the transflective film 112a and is incident to the total reflection film 112b, and the light not transmitted through the transflective film 112a is reflected by the transflective film 112a. . The light reflected by the transflective film 112a forms one of the measurement points 116 and 117. The light incident on the total reflection film 112b is reflected by the total reflection film 112b to form another one of the measurement points 116 and 117.

The light receiver 120 receives light reflected from the measurement points 116 and 117 on the substrate S and converts the light into an electrical signal. The light receiving unit 120 may be provided in two. One of the light receivers 120 receives light reflected from one of the measurement points 116 and 117, and the other is arranged to receive light reflected from the other of the measurement points 116 and 117.

As another example, the light receiver 120 may be provided as one. In this case, the light receiving unit 120 is divided into two regions. The light receiver 120 may be arranged such that one area receives light reflected from one of the measurement points 116 and 117 and the other area receives light reflected from the other of the measurement points 116 and 117. Can be. The signal output from the light receiver 120 is input to the signal processor 130. The signal processor 130 processes the signal input from the light receiver 120 to calculate distance data between the substrate S and the nozzle 22.

According to the present embodiment, the measurement points 116 and 117 formed by the light emitting unit 110 are positioned as shown in FIG. 6. As shown in FIG. 6, one of the two measurement points 116, 117 is forward right of the application position 30, based on the horizontal movement of the application position 30 of the nozzle 22 along the direction of the arrow. Is located at the rear left of the application position (30). The position of the measurement points 116 and 117 may be set by adjusting the angle of the light splitter 112.

The measuring points 116 and 117 move along the path shown in FIG. 7, with the application position 30, when the paste is applied on the substrate S in a closed-loop and clockwise direction. In FIG. 7, the left side of the substrate S is defined as the front and the right side is defined as the rear. Then, while the application position 30 moves along the left line and the front line of the substrate S, the measurement point 116 located on the front right side in FIG. 6 may be positioned before the application position 30.

In addition, while the application position 30 moves along the right line and the rear line of the substrate S, the measurement point 117 located at the rear left side in FIG. 6 may be positioned before the application position 30. That is, in the process of forming the paste pattern P, one of the measurement points 116 and 117 may always be positioned before the application position 30.

In the process of moving the measurement points 116 and 117 as described above, the signal processor 130 may select the distance data by the following process. The signal processor 130 measures the measurement point 116 located on the front right side of the distance data measured from the measurement points 116 and 117 while the application position 30 moves along the left line and the front line of the substrate S. FIG. The distance data measured from are screened. In addition, the signal processor 130 may measure the measurement point located on the rear left side of the distance data measured from the measurement points 116 and 117 while the application position 30 moves along the right line and the rear line of the substrate S. The distance data measured from 117 is selected.

The signal processing unit 130 is provided with information on the application position 30, which of the distance data measured from the measurement points 116 and 117 is the distance data measured from the measurement point located earlier than the application position 30. Can be screened.

The distance data selected by the signal processor 130 may be provided to the controller. The controller may control the height of the nozzle 22 at the position where the paste is to be applied, based on the distance data measured in advance, throughout the entire process of forming the paste pattern P. FIG.

Since the signal processor 130 selects the distance data measured from the position before the application position 30 among the measurement points 116 and 117, the distance data measured from the measurement point moving across the applied paste is May be excluded. Therefore, the distance between the substrate S and the nozzle 22 can be measured without distortion over the entire process of forming the paste pattern P. FIG. As a result, the paste pattern P may be formed so that the width and height do not deviate from the set range.

It is assumed that the distance sensor 100 is set to have a measurement allowance that is slightly wider than the flatness error range of the substrate S. Even in this case, since the distance data measured from passing over the applied paste of the measuring points 116 and 117 is excluded, there is no possibility that the height of the nozzle 22 is controlled by a value outside the measurement allowable range. do. Therefore, an error may not occur due to a value outside the measurement allowance range when the height of the nozzle 22 is controlled.

As another example, although not shown, one of the two measurement points 116, 117 may be located on the front left side of the application position 30, and the other may be located on the rear right side of the application position 30. Even in this case, when the measurement points 116 and 117 are moved along the path of the application position 30 shown in FIG. 7, any one of the measurement points 116 and 117 is more than the application position 30. You can always be ahead. The processing of the distance data measured from the measurement points 116 and 117 may be the same as in the above-described example.

8 illustrates a distance sensor according to another embodiment of the present invention.

As shown in FIG. 8, the distance sensor 200 includes a light emitting unit 210 having two light sources 211. Here, the two light sources 211 project two lights onto the substrate S. The light projected onto the substrate S forms two measurement points 116 and 117 on the substrate S. The light sources 211 may be controlled by a controller to simultaneously project light so that two measurement points 116 and 117 are formed on the substrate S together.

The measurement points 116 and 117 may be located in the same manner as illustrated in FIG. 6. Based on the horizontal movement direction of the application position 30, one of the two measurement points 116, 117 is positioned at the front right side of the application position 30, and the other one is located at the rear left side of the application position 30. Can be. As another example, one of the two measurement points 116, 117 may be located on the front left side of the application position 30, and the other may be located on the rear right side of the application position 30.

The light receiver 220 receives the light reflected from the measurement points 116 and 117, converts the light into an electrical signal, and provides the signal to the signal processor 230. The signal processor 230 receives the information on the application position 30 and selects which of the distance data measured from the measurement points 116 and 117 is the distance data measured from the measurement point located before the application position 30. can do. The process of selecting distance data by the signal processor 230 may be performed in the same manner as in the above-described embodiment. The distance data selected by the signal processor 230 is provided to the controller.

As another example, the light emitter 210 may be controlled to form only the one positioned before the application position 30 among the measurement points 116 and 117. A description with reference to FIGS. 6 and 7 is as follows.

One of the two light sources 211 can emit light so as to form only the measurement point 116 located on the front right side while the application position 30 moves along the left line and front line of the substrate S. FIG. In addition, the other of the two light sources 211 may emit light so as to form only the measurement point 117 located on the rear left side while the application position 30 moves along the right line and the back line of the substrate S. FIG. .

The light sources 211 may be controlled to selectively emit light according to the application position 30 by a control unit having information on the application position 30. The light receiving unit 220 receives the light reflected from the position before the application position 30 among the measuring points 116 and 117, converts the light into an electrical signal, and provides the light signal to the signal processing unit 230. The signal processor 230 calculates the distance data between the substrate S and the nozzle 22 based on the received signal and provides it to the controller.

Here, the signal processor 230 processes only a signal obtained from a position earlier than the application position 30 among the measurement points 116 and 117. Therefore, the signal processor 230 may not include a function of selecting which of the distance data measured from the measurement points 116 and 117 is the distance data measured from the measurement point located before the application position 30.

The present invention can be applied to a paste dispenser having a distance sensor that measures the distance between the substrate and the nozzle.

Claims (6)

delete In the paste dispenser to apply the paste on the substrate while changing the application position of the nozzle, By forming two measuring points on the substrate, the measuring points are located in front and rear of the coating position with respect to the horizontal movement direction of the coating position, and the light is projected so as to be located on both sides of the coating position. Light emitting unit; And And a light receiving unit receiving light reflected from the measurement points and converting the light into an electrical signal. The light emitting unit, A light source for projecting one light; And Dividing the light projected from the light source into two lights to form the measurement points by the divided lights, the light splitter including a total reflection film and a semi-transmissive film disposed closer to the light source than the total reflection film; , A signal processor configured to process the signal input from the light receiver to calculate distance data between the substrate and the nozzle, and to select distance data measured from a measurement point positioned before the coating position among distance data measured from the measurement points. Distance sensor of the paste dispenser, characterized in that. delete delete delete delete