JPH0894984A - Sealing applicator of sealant and its method - Google Patents

Abstract

PURPOSE: To provide a coating applicator of a sealant constituted to applying the sealant at a specified width size and height. CONSTITUTION: This coating applicator includes a nozzle body 24 which is disposed above an X-Y table 4, is driven along a Z direction and discharges the sealant to be applied on a substrate 6, a scope 35 which picks up the image of the nozzle body and the substrate on the X-Y table from the side, an operating section 40 which sets the spacing between the front end of the nozzle body and the front surface of the substrate by the image from the scope 35, a distance detecting sensor 26 which detects the first height position on the front surface of the substrate when the spacing is set by the operating section and the second height position of the front surface of the substrate of the part to be coated with the sealant at the time of applying the sealant and a controller 30 in which the first height position detected by the sensor 26 is stored and which compares the second height position to be detected at the time of applying the sealant with the first height position and corrects the position of the Z direction of the nozzle body in accordance with the comparison.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing agent applying apparatus and method for applying a sealing agent to a liquid crystal substrate.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device is formed by joining a pair of glass substrates so as to face each other with a predetermined gap therebetween and to fill a space between the substrates with liquid crystal. The peripheral portion of the space is sealed with a sealant.

The above sealing agent is applied to the peripheral portion of one of the substrates before the pair of substrates is bonded. When applying the sealant to the substrate, there are a method by screen printing and a method by using a nozzle body as disclosed in JP-A-2-198417.

In the former case, since the screen comes into contact with the substrate, the particles adhering to the screen may be transferred to the substrate, and the sealant is imprinted on the screen with a squeegee and passed through the pattern opening to print. As a result, the coating amount may not be constant.

On the other hand, in the latter case, a constant amount of the sealing agent can be discharged from the nozzle body while keeping a constant interval without bringing the nozzle body into contact with the substrate. It can be applied accurately without soiling.

By the way, if the width and height of the sealant applied to the substrates are not constant, when a pair of substrates are combined, if a large amount of the sealant is present, the sealant protrudes onto the pattern formed on the substrates. However, if the amount is small, a sufficient seal width cannot be obtained, and liquid crystal leakage may occur. Therefore, the width and height of the sealant supplied to the substrate should be μ
It is required to manage with an accuracy of m units.

When applying the sealant using the nozzle body, the width and height of the sealant applied is controlled by controlling the pressure of the sealant discharged from the nozzle body to a constant level. Is being done.

However, the width dimension and the height dimension of the applied sealant are not only affected by the discharge pressure of the sealant, but are greatly affected by the distance between the upper surface of the substrate and the lower end of the nozzle body. It has been confirmed that Therefore, it has been practiced to set the gap between the substrate and the nozzle body and apply the sealant.

Conventionally, in order to set the distance between the substrate and the nozzle body, a reference plate (load cell) is provided in the coating device, the nozzle body is lowered, and the tip of the nozzle body is brought into contact with the reference plate. It has been performed that the distance between the nozzle body and the substrate is set with 0 as a reference point.

However, according to such a method,
When the nozzle body is brought into contact with the reference plate, the zero point may not be constant due to the shape change of the lower end surface of the nozzle body and the inclusion of dust. Therefore, the distance between the nozzle body and the substrate cannot be precisely controlled. There was that.

Even if the distance between the tip of the nozzle body and the upper surface of the substrate is set, the thickness of the substrate is not uniform over the entire substrate.
Further, since the substrate is sucked and held by the XY table, the substrate is bent according to the plane accuracy of the upper surface of the table.

Therefore, even if the distance between the tip of the nozzle body and the upper surface of the substrate is set on the basis of the reference plate, the sealing agent can be applied while moving the nozzle body along a predetermined locus. However, since the interval changes without being maintained constant, the width and height of the sealant may not be constant.

[0013]

As described above, conventionally, the distance between the tip of the nozzle body and the upper surface of the substrate is set as the reference point by bringing the nozzle body into contact with the reference plate. There was a case where it was not possible to set the above-mentioned interval constant due to the change of the condition of.

Further, not only is the thickness of the substrate not uniform over the entire substrate, but since the substrate is bent by being adsorbed on the XY table in accordance with the plane accuracy of the table, the distance between the nozzle body and the substrate is set to the reference plate. Even if it is set by, when the nozzle body is moved and the sealant is applied, the interval between them may change.

An object of the present invention is to make it possible to set the distance between the tip of the nozzle body and the upper surface of the substrate without bringing the tip of the nozzle body into contact with the reference plate. A sealing agent applying apparatus and method capable of applying a sealing agent while maintaining a constant gap between the tip of the nozzle body and the upper surface of the substrate even if the bending occurs due to being sucked and held on the XY table. To provide.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention described in claim 1 is a coating apparatus for coating a liquid crystal substrate with a sealant, the apparatus main body and XY provided on the main body. XY table which is driven in the direction and on which the substrate is placed, and which is provided above the XY table and is driven in the Z direction orthogonal to the moving direction of the XY table and is applied to the substrate. A nozzle body for ejecting a sealing agent, an image pickup means for laterally picking up the nozzle body and the substrate on the XY table, and a distance between the tip of the nozzle body and the upper surface of the substrate by an image from the image pickup means. Setting means for setting, a first height position of the upper surface of the substrate when the interval is set by the setting means integrally provided with the nozzle body, and a seal when applying the sealant. Agent and detecting means for detecting a second height position of the substrate upper surface of the part to be coated is first with height position is stored, which is detected by the detection means,
And a control means for comparing the second height position detected at the time of applying the sealing agent with the first height position and correcting the position of the nozzle body in the Z direction based on the comparison. And

According to a second aspect of the present invention, in a coating method of discharging a sealant from a nozzle body and coating the sealant on a liquid crystal substrate, the nozzle body has a predetermined tip whose tip does not hit the substrate. The step of setting the distance between the nozzle body tip and the substrate upper surface from the imaged image of the nozzle body and the substrate, and the nozzle body tip and the substrate upper surface. When the interval is set, the step of detecting and storing the first height position of the upper surface of the substrate with the nozzle body as a reference, and the seal agent is applied with the nozzle body as a reference when applying the sealant. The second height position of the upper surface of the substrate of the part to be detected is detected, the second height position is compared with the first height position, and the Z direction position of the nozzle body is corrected based on the comparison. And the process of And wherein the door.

[0018]

According to the invention described in claims 1 and 2, the distance between the tip of the nozzle body and the upper surface of the substrate can be set without contacting the nozzle body with the substrate, and the thickness of the substrate can be set. Even if there is an error in the position or the substrate is bent due to being adsorbed on the XY table, the sealant can be applied while controlling the distance between the tip of the nozzle body and the upper surface of the substrate to be constant.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a front view of the sealant applying device of the present invention, in which 1 is the main body of the device. This body 1 is a vibration isolation table 2
Has a base 3 supported via. An XY table 4 driven in the XY directions (two-dimensional directions) is provided on the base 3. As shown in FIG. 1, the XY table 4 includes an X table 4a that is driven in the X direction by an X drive source 5a that is a motor, and a Y drive source 5b that is also provided on the X table 4a and that is also a motor.
Y table 4b driven in the direction.

A stage 5 having a suction mechanism (not shown) is provided on the XY table 4, and a glass substrate 6 for forming a liquid crystal display device is suction-held on the stage 5 by the suction mechanism. It has become so.

A gate-shaped mount 7 is provided above the base 3. A nozzle up / down mechanism 8, a scope up / down mechanism 9, and an alignment camera adjusting mechanism 11 are mounted on this gantry 7.
Is provided.

The nozzle up / down mechanism 8 is shown in FIG.
As shown in (b), it has a fixing plate 21 attached and fixed to the gantry 7. A movable plate 22 is provided on the fixed plate 21 so as to be movable along a Z direction perpendicular to a plane formed by the XY directions. The movable plate 22 is the fixed plate 2
1 μm in the Z direction by the servomotor 23 provided in
It is designed to be driven with unit accuracy.

The movable plate 22 is integrally provided with a nozzle body 24 and a distance detection sensor 26 via a fine adjustment mechanism 25 in the Z direction. The nozzle body 24 is for ejecting the sealant that is supplied and pressurized inside and applies it along the peripheral portion of the substrate 6 that is adsorbed and held on the stage 5 as described later. Distance detection sensor 2
6 detects the distance between the tip of the nozzle body 24 and the upper surface of the substrate 6, that is, the height of the upper surface of the substrate with an accuracy of μm.

When the sealant is applied to the upper surface of the substrate 6, the distance between the tip of the nozzle body 24 and the upper surface of the substrate 6 is controlled to be constant by the detection signal from the distance detecting sensor 26 as described later. It

The detection signal detected by the distance detection sensor 26, that is, the height signal at a predetermined position of the substrate 6 is shown in FIG.
Is input to the control device 30 shown in FIG. This control device 31
When the XY table 4 is driven to apply the sealant to the substrate 6, the distance G between the tip of the nozzle body 24 and the upper surface of the substrate 6, which is set as described later, is detected by the distance detection sensor 26. Correct by the signal.

That is, as will be described later, even if the detection signal from the distance detection sensor 26 causes an error in the thickness of the substrate 6 or the substrate 6 is bent due to suction, its upper surface and the tip of the nozzle body 24. The sealant is applied while keeping the gap G between and constant.

The scope up / down mechanism 9 is shown in FIG.
As shown in (b), it has a fixing plate 31 attached and fixed to the gantry 7. A movable plate 32 is provided on the fixed plate 31 so as to be movable in the Z direction. This movable plate 32
Is driven in the Z direction by a microcylinder 33 provided on the fixed plate 31, and an XY precision stage 34 is provided at the lower end thereof. This X
A scope 35 including a CCD camera as an image pickup means is held on the Y precision stage 34.

When the micro cylinder 34 is operated and the scope 35 is lowered while the XY table 4 is retracted from below the scope 35, the scope 35 is placed on the substrate 6 mounted on the XY table 4. And the tip of the nozzle body 24 whose tip is opposed to the upper surface of the substrate 6 is imaged. The imaging part of the scope 35 is illuminated by the light source lamp L shown in FIG.

The image pickup signal of the scope 34 is sent to and displayed on the monitor 36 shown in FIG. The monitor 36 is shown in FIG.
As shown in (a), an image of the substrate 6 and the nozzle body 24 and a scale 37 is displayed at a position corresponding to the image.
Therefore, with this scale 37, the upper surface of the substrate 6 and
The gap G from the tip of the nozzle body 24 can be read, and the gap G can be set to an arbitrary value by adjusting the position of the nozzle body 24 in the Z direction by the servo motor 23.

The position of the nozzle body 24 in the Z direction is set by the operating section 40 connected to the control device 30. As shown in FIG. 3, the operation section 40 includes a start switch 39, an ascending switch 41, and a descending switch 4 related to the setting of the gap G between the upper surface of the substrate 6 and the tip of the nozzle body 24.
2, setting switch 43, return switch 44 is provided,
Further, a calibration switch 45, an operation switch 46, and a stop switch 47 related to the application of the sealing agent are provided. The operation unit 40 may be a keyboard or a display capable of touch input.

When the start switch 39 is turned on, the substrate 6 placed on the stage 5 is vacuum-sucked to position the XY table 4 at the gap setting position. Then, the scope 35 descends and the monitor 36 displays an image of the upper surface of the substrate 6 and the lower end of the nozzle body 24. When the gap G is first set, a reference substrate having a shape corresponding to the substrate 6 may be used.

The ascending switch 41 and the descending switch 42
Operates the servo motor 23 to operate the nozzle body 24.
The setting switch 43 sets the gap G by the rise and fall switches and then turns it on to set the gap G to the controller 3
Store to 0. This completes the setting of the interval G.

The return switch 44 is turned on after setting the gap G to raise the scope 35 and return the XY table 4 to the initial position. When the calibration switch 45 is turned on after setting the gap G, the zero point of the length measurement is automatically searched and the position thereof is stored in the control device 30. At the time of applying the sealant, the detection signal of the distance detection sensor 26 is compared with the stored zero point, and the servo motor 23 is driven according to the difference to control the position of the nozzle body 24 in the Z direction. That is, when the gap G changes due to a change in the thickness of the substrate 6 or a deflection when the sealant is applied, the gap G is corrected according to the change, and therefore the nozzle body 24
The distance between the tip and the upper surface of the substrate 6 is maintained constant with an accuracy of μm.

In this embodiment, the zero point measured by turning on the calibration switch 45, that is, the height of the upper surface of the substrate 6 when the gap G is set is the first height position, and the sealant is used. The height of the upper surface of the substrate 6 detected by the distance detection sensor 26 at the time of coating is defined as the second height position.

The operation switch 46 is for starting the application of the sealing agent, and when it is turned on, the sealing agent is discharged from the nozzle body 24 at a predetermined pressure, and
The XY table 4 is driven in a predetermined locus in the XY directions based on data preset in the control device 30. Thereby, the sealant S is applied in a rectangular frame shape along a predetermined position of the substrate 6 on the XY table 4, that is, along the peripheral portion of the circuit pattern P formed on the substrate 6 shown in FIG. 2B. Become.

The alignment camera adjusting mechanism 11 has
As shown in FIGS. 7A and 7B, it has a fixing plate 51 that is attached and fixed to the gantry 7. A movable plate 52 is provided on the fixed plate 51 so that the movable plate 52 can be finely adjusted in the three-dimensional directions by fine adjustment mechanisms 53a to 53c in the X, Y, and Z directions, each of which includes a micrometer. An alignment lamella 54 is provided on the movable plate 51 with its optical axis along the Z direction.

The alignment camera 54 picks up an image of the substrate 6 sucked and held on the XY table 4. The image pickup signal from the alignment camera 54 is input to the image processing unit 55 and processed, and the image signal is input to the control device 30.

Cross-shaped alignment marks m are formed at the four corners of the substrate 6 as shown in FIG. 2 (b). Therefore, the control device 30 controls the image processing unit 5
By processing the image signal from 5, the XY of the substrate 6 is processed.
The position on the table 4 is calculated. This calculation result is compared with a preset value set in the control device 30. If there is a difference in the comparison result, when the sealant is applied to the substrate 6, the XY table 4 is driven in the XY directions. The trajectory is corrected.

That is, even if the position of the substrate 6 held on the XY table 4 is not constant, the drive of the XY table 4 in the XY directions is corrected, so that the sealant is applied to the predetermined position of the substrate 6. It can be applied.

Next, the procedure for applying the sealant to the substrate 6 by the apparatus having the above-mentioned structure will be described. First, with the XY table 4 positioned at the initial position, the stage 5
The substrate 6 (or a reference substrate having a shape similar to that of the substrate 6) is placed on, and the start switch 39 of the operation unit 40 is turned on. As a result, the substrate 6 placed on the stage 5 is vacuum-sucked, and the XY table 4 is driven to the gap setting position. Then, the scope 35 of the scope up-and-down mechanism 9 descends and images the lower end of the nozzle body 24 and the substrate 6 from the side.

The image from the scope 35 is displayed on the monitor 36.
Is displayed in. Since the scale 37 is also displayed on the monitor 36 at the same time, the gap G between the lower end surface of the nozzle body 24 and the upper surface of the substrate 6 can be visually confirmed by the scale 37.

The gap G is set to a predetermined value depending on the width and height of the sealant applied. For example, in this embodiment, the scale 37 is the second scale 5
It is set to 0 μm. That is, while watching the image on the monitor 36, the nozzle body 24 is raised or lowered by the raising switch 41 or the lowering switch 42, and the interval G is set to 5
Set to 0 μm.

When the setting of the gap G is completed, the setting switch 43 is turned on so that the set gap G can be adjusted.
Stored in 0. Then, by turning on the calibration switch 45, the zero point of the distance detection sensor 26 when the gap G is 50 μm is automatically searched for and stored in the control device 30. That is, the first height position of the upper surface of the substrate 6 is stored.

Next, by turning on the return switch 44, the scope 35 is raised and the XY table 4 is returned to the initial position. When a reference substrate similar to that is used instead of the substrate 6 when setting the gap G, when the XY table 4 returns to the initial position after setting the gap G, the reference substrate is removed from the stage 5 and a sealant is applied. The substrate 6 is replaced.

Next, the operation switch 46 is turned on to apply the sealant. As a result, the substrate 6 is vacuum-sucked to the stage 5 and the substrate 6 is imaged by the alignment camera 54. The image pickup signal is the image processing unit 55.
The image signal is processed by the control device 30 and the position of the alignment mark m in the XY directions is calculated. From this calculation result, XY of the substrate 6 on the stage 5
The inclination of the direction is obtained, and its position is compared with a preset set value.

If there is a difference between the actual position of the substrate 6 and the preset value, the drive of the XY table 4 is corrected according to the difference when the sealant is applied. Therefore, while the XY table 4 is driven in the XY directions,
When the sealant is discharged from the nozzle body 24 and applied,
Regardless of the holding state (inclination in the XY directions) of the substrate 6, the sealing agent can be applied to the predetermined position of the substrate 6.

When the sealant is applied to the substrate 6, the distance detection sensor 26 is moved to the substrate 6, that is, the second upper surface of the substrate.
The height position of the control unit 3 and detects its second height position.
Compare with a first height position, which is a zero point preset to zero.

If there is a difference between the first height position and the second height position, a drive signal is output from the control device 30 to the servo motor 23 of the nozzle up / down mechanism 8 according to the difference, and the difference is generated. The movable body 22, which is integrally provided with the nozzle body 24 and the distance detection sensor 26, is vertically driven to a height where 0 is zero.

As a result, the height of the nozzle body 24 is adjusted so that the second height position to the upper surface of the substrate 6 detected by the distance detection sensor 26 coincides with the preset first height position (zero point). The sealing agent is applied while the temperature is controlled.

That is, since the sealant is applied while keeping the distance between the upper surface of the substrate 6 and the lower end surface of the nozzle body 24 constant, even if the thickness of the substrate 6 is not uniform or is warped. The sealing agent is applied while the gap G between the nozzle body 24 and the substrate 6 is corrected to be constant. Therefore, it is possible to prevent the width dimension and the height dimension of the sealant applied to the substrate 6 from varying.

The present invention is not limited to the above-mentioned embodiment, but can be variously modified without departing from the gist of the invention. For example, in the above-mentioned one embodiment, as setting means for setting the distance between the upper surface of the substrate and the lower end surface of the nozzle body, these are imaged from the side by a scope, and the up and down switches are checked while visually checking the distance from the image. Although the setting is performed manually, the setting can be performed automatically as follows.

That is, an image obtained by laterally picking up the substrate and the nozzle body with the scope is processed by the image processing section, and the distance between the substrate and the nozzle body is calculated from the processed signal. In addition, a reference interval is set in advance in the control device,
The set value and the calculated value are compared, and the servo motor is driven based on the comparison. With this configuration, the interval that was manually set can be automatically set, and like the above-described embodiment, the setting can be performed without bringing the nozzle body into contact with the substrate.

Further, one distance detecting sensor is used as the detecting means, the first height position of the upper surface of the substrate when the distance is set by the one distance detecting sensor, and the second height of the upper surface of the substrate when the sealant is applied. However, it is needless to say that these two detections may be performed by separate sensors.

[0054]

As described above, according to the present invention, the tip of the nozzle body and the upper surface of the substrate are imaged, the distance between the tip of the nozzle body and the upper surface of the substrate is set based on the image, and the height of the upper surface of the substrate at that time is set. Is detected and stored as the first height position, and the height of the upper surface of the substrate at the portion where the sealant is applied when the sealant is applied is detected as the second height position and the second height is detected. The position was compared with the first height position, and the sealant was applied while controlling the height of the nozzle body based on the comparison.

Therefore, these intervals can be set without bringing the nozzle body into contact with the substrate, and the thickness of the substrate is not uniform, or the substrate may be bent by being sucked and held, so that Even if the height of the top surface changes partially, the sealing agent is applied while correcting the gap between the top surface of the substrate and the lower end of the nozzle body, so the width and height dimensions of the applied sealing agent Can be constant.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2A is an explanatory view of a monitor screen when setting the distance between the nozzle body and the substrate, and FIG. 2B is a plan view of the substrate.

FIG. 3 is an explanatory diagram of an operation unit that is also connected to the control device.

FIG. 4 is a front view of the coating device.

FIG. 5A is a front view of the nozzle up-and-down mechanism,
(B) is also a side view.

FIG. 6A is a front view of the scope up / down mechanism,
(B) is also a side view.

7A is a front view of the alignment camera adjusting mechanism, and FIG. 7B is a side view of the same.

[Explanation of symbols]

4 ... XY table, 6 ... Liquid crystal substrate, 9 ... Scope up / down mechanism (imaging means), 24 ... Nozzle body, 26 ... Distance detection sensor (detection means), 30 ... Control device (control means), 35
... scope (imaging means), 36 ... monitor (setting means),
40 ... Operation part (setting means), 41 ... Raising switch (setting means), 42 ... Falling switch (setting means), 43 ... Setting switch (setting means).

Claims (2)

[Claims] 1. A coating apparatus for coating a liquid crystal substrate with a sealing agent, comprising: a main body of the apparatus; an XY table which is provided in the main body and is mounted on the upper surface of the XY table; A nozzle body that is provided above the nozzle and that is driven along a Z direction that is orthogonal to the moving direction of the XY table and that discharges the sealant applied to the substrate; and the nozzle body and the substrate on the XY table. Image pickup means for picking up images from the side, setting means for setting the distance between the tip of the nozzle body and the upper surface of the substrate by the image from the image pickup means, and the distance set by the setting means provided integrally with the nozzle body Detecting means for detecting a first height position of the upper surface of the substrate at the time of the above and a second height position of the upper surface of the substrate at a portion to which the sealant is applied when the sealant is applied, The first height position detected by the detecting means is stored, and the second height position detected when applying the sealant is compared with the first height position, and based on the comparison, the above-mentioned second height position is compared. A controller for correcting the position of the nozzle body in the Z direction, comprising: a sealant applicator. 2. A coating method in which a sealing agent is discharged from a nozzle body and the sealing agent is applied to a liquid crystal substrate, and the nozzle body is lowered to a predetermined position where its tip does not hit the substrate, and an image is taken. A step of setting a distance between the tip of the nozzle body and the upper surface of the substrate from the imaged image of the nozzle body and the substrate, and a step of setting a distance between the tip of the nozzle body and the upper surface of the substrate. A step of detecting and storing the first height position of the upper surface of the substrate with the nozzle body as a reference; and a second step of the portion of the upper surface of the substrate where the sealant is applied with the nozzle body as a reference when applying the sealant. The height position of
And a step of comparing the second height position with the first height position and correcting the position of the nozzle body in the Z direction based on the comparison. .