JP2752553B2 - Paste coating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste dispenser for applying and drawing a paste pattern of a desired shape on a substrate placed on a table.

[0002]

2. Description of the Related Art A technique of drawing a paste film of a desired pattern on a substrate by moving the nozzle and the substrate relatively up and down and back and forth and left and right while discharging the paste from a nozzle provided at the tip of a paste storage cylinder. For example, as disclosed in Japanese Patent Application Laid-Open No. 2-52742, the nozzle is moved while the substrate is relatively moved with respect to the nozzle, and the gap (or interval) between the tip of the nozzle and the substrate is adjusted. 2. Description of the Related Art There is known a discharge drawing technique in which a resistive paste is discharged from a paste discharge port at a tip onto a substrate to form a desired resistance pattern.

[0003]

However, when a liquid crystal sealing film is formed by drawing on a recent high definition liquid crystal display substrate using the above-mentioned conventional technology, the following problems arise. I found it.

That is, in the above-described conventional discharge drawing technique, when a measurement position of a distance sensor passes over a drawn paste pattern having a certain thickness while performing a gap measurement, a nozzle and a nozzle are formed at a portion where a new paste film is formed. The substrate is held at a desired gap. In other words, the nozzle height cannot be set to the set value, and the width of the sealing film is increased or the height of the sealing film is increased at that position. It has been found that a new problem arises in that the sealing film cannot be formed by drawing.

An object of the present invention is to solve such a problem and to keep a nozzle and a substrate in a desired gap even when a measurement position of a distance sensor passes over a drawn paste pattern while performing a gap measurement. It is an object of the present invention to provide a paste coating machine capable of drawing a desired pattern.

[0006]

To achieve the above object of the Invention The present invention comprises a measuring means for measuring a distance between the paste discharge port and the surface of the substrate of the nozzle, measured values of the measuring means the
Setting the distance between the paste discharge port of the nozzle and the surface of the substrate
A time interval exceeding a threshold value for the value, an interval holding means for holding an interval between the paste discharge port of the nozzle and the surface of the substrate at a value immediately before the measurement value of the measurement means exceeds the threshold value, and a measurement value of the measurement means. when is not exceeding the threshold value, providing a gap adjusting means for adjusting the predetermined value interval is pre-specified for the paste discharge port and the substrate surface of the nozzle.

[0007]

When a paste pattern is drawn on a substrate, for example, the substrate is moved to change the relative positional relationship between the paste discharge port of the nozzle and the substrate, and the paste is discharged onto the substrate from the paste discharge port of the nozzle. But at this time,
At the same time, the distance between the paste discharge port of the nozzle and the surface of the substrate is measured by the measuring means, and the distance adjusting means adjusts the distance between the paste discharge port of the nozzle and the surface of the substrate according to the measurement result. Set to the set value.

In some cases, depending on the paste pattern to be drawn, the measuring position of the measuring means may cross the already formed paste film, and in this case, the measuring means may determine the distance between the paste discharge port of the nozzle and the surface of the substrate. Is determined to be sufficiently narrow.

However, according to the present invention, the measured value of the measuring means exceeds the above threshold value. At this time, it is determined that the measuring position of the measuring means is on the already formed paste film, and the paste discharge port is determined. Is fixed to the value immediately before without changing the distance between the substrate and the surface of the substrate. Thus, the width and thickness of the paste film to be formed does not change, can be obtained accurately Bae <br/> over strike pattern of a desired shape.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view showing one embodiment of a paste applicator according to the present invention, wherein 1 is a nozzle, 2 is a paste storage cylinder,
Is an optical displacement meter as a distance sensor, 4 is a Z axis table section, 5 is an X axis table section, 6 is a Y axis table section, 7 is a substrate, 8 is a substrate suction section, 9 is a gantry section, and 10 is a Z axis. A table support, 11 is a control device, 12 is a nozzle support, and PC is a paste cartridge.

In FIG. 1, an X-axis table section 5 is fixed on a gantry section 9, and a Y-axis table section 6 is mounted on the X-axis table section 5 so as to be movable in the X-axis direction. The substrate suction unit 8 is mounted on the Y-axis table 6 so as to be movable in the Y-axis direction. The substrate 7 is mounted on the substrate suction portion 8 by suction so that, for example, four sides thereof are parallel to both X and Y axis directions. The X and Y axis table units 5 and 6 are controlled and driven by the control device 11, respectively. That is, when the X-axis table unit 5 is driven, the Y-axis table unit 6 and the substrate suction unit 8 mounted thereon move in the X-axis direction. The suction unit 8 moves in the Y-axis direction. Therefore, the control device 11
When the X and Y axis table units 5 and 6 are respectively moved by an arbitrary distance, the substrate 7 moves by an arbitrary position in an arbitrary direction in a plane parallel to the gantry unit 9.

A Z-axis table support 10 is provided on the surface of the gantry 9, and the Z-axis table 4 is attached to the Z-axis table support 10. The Z-axis table unit 4 is movable in the Z-axis direction (vertical direction), connects the nozzle 1 and the paste storage tube 2, and positions the nozzle 1 near the lower side of the optical displacement meter 3. The support tool 12 is placed. Control driving of the Z-axis table unit 4 in the Z-axis direction is also performed by the control device 11. When the controller 11 drives the Z-axis table 4, the nozzle 1, the paste storage cylinder 2,
The Z-axis table support 10 and the optical displacement meter 3 move in the vertical direction (Z-axis direction).

Here, the nozzle 1, the paste storage cylinder 2, and the nozzle support 12 for connecting them are integrated to form one paste cartridge PC.

When a paste film having a desired pattern is formed on the substrate 7 placed on the substrate suction portion 8 in the paste coating machine having the above-described configuration, first, the Z-axis table portion 4 is driven by the control device 11, The tip of the nozzle 1 is positioned at a predetermined height from the substrate 7.

Here, it is assumed that the predetermined height is equal to the thickness of the paste film to be formed on the substrate.

When the height of the nozzle tip is set as described above, the control device 11 controls the driving of the X-axis table unit 5 and the Y-axis table unit 6 to move the substrate 7 on the substrate suction unit 8. While moving in both XY directions on the horizontal plane, the nozzle 1
The paste stored in the paste storage tube 2 is discharged onto the substrate 7 by compressed air or a piston in the paste storage tube 2 at a constant discharge amount per unit time from the discharge port at the tip of the paste, and the paste is formed on the substrate 7 in a desired pattern. The film is drawn directly.

FIGS. 2A and 2B are a side view and a front view showing the relationship between the paste cartridge PC and the optical displacement meter 3 when drawing a paste pattern. Reference numeral 13 denotes a paste, and FIG. Corresponding parts have the same reference characters allotted.

2 (a) and 2 (b), the paste storage cylinder 2 is attached to a fixed portion (not shown) of the Z-axis table section 4 via a nozzle support 12, and the optical displacement meter 3 is As shown in the figure, the paste storage cylinder 2 and the optical displacement meter 3 are attached to the Z-axis table 4 so as to be in parallel. However, in order to make the measurement position S of the optical displacement meter 3 on the substrate 7 close to the tip of the nozzle 1,
The nozzle 1 is attached to the tip of the nozzle support 12, and this tip is located below the lower surface of the optical displacement meter 3. The nozzle 1, the paste storage cylinder 2, and the inside of the nozzle support 12 are communicated.

The light emitted from a light emitting element (not shown) of the optical displacement meter 3 emits a projection light obliquely as indicated by a two-point oblique line, and the light reflected at the measurement position S on the substrate 7 is an optical displacement meter. The light is received by a light receiving element 3 (not shown). At this time, the tip of the nozzle support 12 enters a range including the incident angle of the projection light and the reflection angle of the reflected light at the measurement position S so that it does not block the light from the light emitting element to the light receiving element. Like that. Since the arrangement relationship between the light emitting element and the light receiving element in the optical displacement meter 3 is constant, the reflected light is applied to the light receiving element in accordance with the distance between the paste discharge port of the nozzle 1 and the surface of the substrate 7. The irradiation state is different, so that the distance between the paste discharge port of the nozzle 1 and the surface of the substrate 7 can be measured based on the amount of light received by the light receiving element.

FIG. 3 is a diagram showing an example of a paste pattern to be drawn on the substrate 7 and a drawing process thereof. A solid line P indicates the paste pattern.

In the figure, when a paste pattern is drawn in the direction of the arrow, drawing starts from the portion surrounded by a double circle, and the X-axis table portions 5 and Y
The driving direction of the axis table 6 is changed.

A black dot near a double circle or a position surrounded by a circle (paste application point) indicates a measurement position S of the optical displacement meter 3 at that position. As is clear from the display position relationship between the position surrounded by the double circle or the circle and the measurement point S with respect to the position, the optical displacement meter 3 with respect to the paste application point of the nozzle 1
The direction of the measurement position S is inclined by 45 degrees with respect to the XY axes. Also, here, the optical displacement meter 3
Measures the distance between the discharge port of the nozzle 1 and the surface of the substrate 7 at the measurement position S. The measurement value obtained by the optical displacement meter 3 caused by the undulation of the substrate 7 and the measurement of the distance between the discharge port of the nozzle 1 and the surface of the substrate 7 If the error from the actual interval is 1 μm or less, the paste application point of the nozzle 1 and the measurement position S of the optical displacement meter 3 are extremely close so that this can be ignored. That is, the measurement error range of the distance between the ejection port of the nozzle 1 and the surface of the substrate 7 by the optical displacement meter 3 can be set to 1 μm or less.

The paste pattern is drawn in the direction of the arrow in FIG. 3. When the paste application point reaches the point A indicated by the dotted line circle, the measurement position S of the optical displacement meter 3 is changed to the already drawn paste film. Will pass over. In this case, the control device 11 determines that the measurement position S of the optical displacement meter 3 passes over the paste film already drawn, and drives the discharge port of the nozzle 1 and the substrate without driving the Z-axis table unit 4. 7, and the paste application is continued while maintaining a desired gap. When the control device 11 determines that the measurement position S of the optical displacement meter 3 has passed over the paste film already drawn, the control device 11 drives the Z-axis table unit 4 again to continue the paste application.

Thus, the pattern as shown in FIG. 3 can be easily formed without causing a variation in the line width.

FIG. 4 shows a situation where the measurement position S of the optical displacement meter 3 passes over the paste film already drawn at the point A in FIG.

In this figure, in this case, the measurement point S of the optical displacement meter 7 is on the paste film already drawn, and the distance from the film to the discharge port of the nozzle 1 is measured. Is reflected in the driving of the Z-axis table 4 as it is, the gap between the discharge port of the nozzle 1 and the substrate 7 is reduced by the thickness of the paste film, and the Z-axis table 4 is driven upward. In fact, nozzle 1
In this embodiment, the control device 11 does not drive the Z-axis table unit 4 and the gap between the discharge port of the nozzle 1 and the substrate 7 remains unchanged. It is held and the drawing is continued.

FIG. 5 is a block diagram showing a control system according to this embodiment for performing the above-described control drive, wherein 14 is an amplifier, 15 is a Z-axis motor controller, 16 is a Z-axis motor driver, 17 is a motor, Reference numeral 18 denotes an encoder, 19 denotes a microcomputer (hereinafter, referred to as a microcomputer), 20 denotes a data input device, and portions corresponding to the above-described drawings are denoted by the same reference numerals.

In FIG. 1, the control device 11 is a microcomputer 1
9, a Z-axis motor controller 15, a Z-axis motor driver 16, and the like, and the microcomputer 19 is configured to input a data input device 20 such as a keyboard or a touch panel to input a paste pattern to be drawn. And data for designating the gap between the optical displacement sensor 3 and the substrate 7, and the measurement data output from the optical displacement meter 3 and amplified by the amplifier 14. The microcomputer 19 includes a RAM (random access memory) for storing various data such as input data from the data input device 20, a ROM (read only memory) for storing programs,
A CPU that performs arithmetic processing on data stored in the RAM according to this program and generates drive control information for operating the paste applicator shown in FIG. 1 as described above.
(Central processing unit) and an input / output circuit for inputting / outputting various data.

During the drawing of the paste pattern, the microcomputer 19
Compares the specified paste film thickness value (hereinafter, referred to as a film thickness threshold value) of the input data stored in the RAM with the actually measured data from the optical displacement meter 3 and determines that the actually measured data indicates the film thickness threshold value. If it is out of a sufficiently narrow range, a driving command value is output to the Z-axis motor controller 15. The Z-axis motor controller 15 sends the Z-axis motor driver 1 according to this command value.
6, the motor 17 is driven to move the Z-axis table 4 up and down so that the measured data from the optical displacement meter 3 falls within a sufficiently narrow range including the film thickness threshold. Thereby, the gap between the discharge port of the nozzle 1 and the substrate 7 is set to the specified value.

At 18, the rotation amount of the motor 17 is measured by the encoder 18, the measurement result is returned to the Z-axis motor driver 16, and the feedback control of the motor 17 is performed.

FIG. 6 is a flowchart showing the overall schematic operation of the embodiment shown in FIG.

In the figure, when the power is turned on (step 600), the control device 11 performs initialization (step 601). In this initial setting operation, as shown in FIG. 7, first, the Z-axis table unit 4, the X-axis table unit 5, and the Y-axis table unit 6 are positioned at predetermined origin positions (step 700), and the data input device is used. 20
The setting of paste pattern data and substrate position data from FIG. 5 (step 701) and the setting of paste discharge end position data (step 702) are also performed.

When the initial setting is completed, in FIG. 6, the substrate 7 is mounted on the substrate sucking section 8 and sucked (Step 602), and a paste film forming step (Step 603) is performed.
to go into. Until the formation of the paste pattern is completed, the substrate suction unit 8 keeps sucking the substrate 7. When the formation of the paste pattern is completed, the substrate 7 is unloaded (step 6).
04) If there is a substrate 7 on which a paste pattern is to be drawn (step 605), the process from step 602 is restarted for that substrate 7. When the drawing of the paste pattern is completed for all the substrates (step 60)
5) The work ends.

FIG. 8 is a flowchart showing the paste film forming step (step 603) of FIG. 6 in more detail.

In the figure, first, the control device 11 drives the X-axis table unit 5 and the Y-axis table unit 6 in order to obtain a desired pattern on the substrate 7, and the tip of the nozzle 1 The paste film formation start position is set (step 800). Subsequently, the height of the nozzle 1 is set to the set value, and the interval between the surface of the substrate 7 and the discharge port of the nozzle 1 is set to a specified value (step 801). Next, while driving the X-axis table unit 5 and the Y-axis table unit 6, the discharge of the paste from the tip of the nozzle 1 is started (step 802).

Then, the measured data is input from the optical displacement meter 3 to measure the undulation of the surface of the substrate 7 (step 80).
3) The measurement position S of the optical displacement meter 3 is obtained from the measured data.
Is determined on the already applied paste film (step 804). If the measurement position S is not on the paste film, the Z-axis table unit 4 is driven up and down based on the actually measured data to correct the height of the discharge port of the nozzle 1 by the correction value, and the discharge port of the nozzle 1 Is maintained at a designated value (step 806). On the other hand, if it is determined that the measurement position S is passing over the paste film (step 80)
4), without performing the processing of steps 805 and 806, the height of the discharge port of the nozzle 1 is maintained at the height before detecting that the measurement position S is on the paste film, that is, the formation of the paste film Continue working.

Further, even when the measurement position S passes over the paste film, the height of the discharge port of the nozzle 1 is not corrected. When the measurement position S passes over the paste film having a small width, the height between the surface of the substrate 7 and the tip of the nozzle 1 hardly changes in most cases. However, even if the distance between the surface of the substrate 7 and the discharge port of the nozzle 1 is maintained as it is, by keeping the paste discharge conditions during this period, the measurement position S of the formed paste film is different from that on the paste film. Thus, the same shape as in the case immediately before is maintained, so that a paste pattern having a desired shape can be obtained.

If the paste pattern has not been completed yet and there is no instruction to end the discharge of the paste from the paste storage cylinder 2 (step 807), and if it has not reached the drawing end position (step 809), the flow returns to step 803. , And the above operation is continued.

As described above, steps 803 to 807, 80
9 is repeated, the drawing operation proceeds, and the entire paste pattern is drawn. When there is an instruction to end the paste discharge (step 807), the paste discharge ends (step 808), and the drawing ends. When the position is reached (step 809), the Z-axis table unit 4 is driven to raise the nozzle 1 (step 810), and the paste pattern forming operation is completed.

Next, a method of determining whether the measurement point S of the optical displacement meter 3 is on the paste film will be described.

FIG. 9 is a view for explaining a specific example of this, and the discharge of the nozzle 1 when the measurement position S of the optical displacement meter 3 passes over the paste film 13 drawn on the substrate 7 is shown. The situation of the detection result of the gap between the outlet and the substrate 7 is shown.

In the figure, a paste film determination threshold value slightly higher than the set height of the discharge port (nozzle tip) of the nozzle 1 is set, and the optical displacement meter 3 is measured at a constant sampling cycle. If the measurement value (shown by a black circle) exceeds the paste film determination threshold value, it is determined that the measurement point S is on the paste film.

FIG. 10 is for explaining another specific example of the above-mentioned determination method. In this specific example, measurement data of the optical displacement meter 3 is taken as a continuous value, and a determination threshold (paste film determination threshold) that defines a predetermined range is set for a waveform obtained by differentiating the measurement data. . If this differential value deviates from this range, it is determined that the measurement position S has laid on the paste film, and if the next differential value deviates from this range, it is determined that the measurement film has deviated from the paste film.

While one embodiment of the present invention has been described above, the present invention is not limited to only this embodiment. For example, (1) the paste pattern may be drawn by moving the nozzle 1 in the X and Y axis directions with respect to the fixed substrate.

(2) In FIG. 8, step 800 may be performed after step 801.

(3) As a distance sensor, the substrate 7
The swell may be measured.

[0047]

As described above, according to the present invention, even if the measurement position of the distance sensor passes over the already applied paste film, the distance between the paste discharge port of the nozzle and the surface of the substrate is maintained. A uniform thickness over the entire paste pattern to be drawn, which can be maintained at a specified desired gap;
Can be thickness.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of one embodiment of a paste coating machine according to the present invention.

2A and 2B are a side view and a front view showing a positional relationship between a nozzle and an optical displacement meter in FIG.

FIG. 3 is a drawing of a page drawn on a substrate in the embodiment shown in FIG. 1;
FIG. 4 is a diagram showing an example of a stop pattern and a drawing process thereof.

FIG. 4 is a view showing a situation where a measurement position of the optical displacement meter passes over a pasted film already drawn at a point A in FIG. 3;

FIG. 5 is a block diagram showing a specific example of a control drive system in the embodiment shown in FIG.

FIG. 6 is a flowchart showing an overall operation of the embodiment shown in FIG. 1;

FIG. 7 is a flowchart showing details of an initial setting step in FIG. 6;

FIG. 8 is a flowchart showing details of a paste film forming step in FIG. 6;

FIG. 9 is a diagram showing a specific example of a method for determining whether or not the measurement position in FIG. 8 is on a paste film that has already been formed.

10 is a diagram showing another specific example of a method for determining whether or not the measurement position in FIG. 8 is on a paste film that has already been formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Paste storage cylinder 3 Optical displacement meter (distance sensor) 4 Z-axis table part 5 X-axis table part 6 Y-axis table part 7 Substrate 11 Control device 12 Nozzle support 13 P Strut 19 Microcomputer 20 Data input device P Paste pattern S Measurement position

Claims (3)

(57) [Claims] 1. A relative position between a substrate held on a table and a nozzle is relatively changed while discharging paste filled in the paste storage cylinder from a paste discharge port of a nozzle provided in the paste storage cylinder. A paste applicator for drawing a pattern of a desired shape with a paste on the substrate, a measuring means for measuring a distance between a paste discharge port of the nozzle and a surface of the substrate, and a measured value of the measuring means for the nozzle. Paste discharge port and the base
A period exceeding the threshold value for the set value of the distance from the surface of the plate ,
A distance holding means for holding a gap between the paste discharge port and the substrate surface of the nozzle to a value immediately before the measurement value of said measuring means exceeds a threshold value, when the measured value of said measuring means does not exceed the threshold value , paste applying machine which is characterized in that a and interval adjusting means for adjusting the predetermined value interval is pre-specified for the paste discharge port and the substrate surface of the nozzle. 2. The apparatus according to claim 1, wherein the interval holding unit includes a set value for an interval between the paste discharge port of the nozzle and the surface of the substrate, and a unit for inputting the threshold value for the set value. Characteristic paste application machine. 3. A substrate is held on a movable table so as to face a paste discharge port of a nozzle provided in a paste storage cylinder, and the substrate is discharged while discharging the paste filled in the paste storage cylinder from the nozzle. Is moved relative to the nozzle, a paste coating machine that draws a desired pattern of paste on the substrate, a distance sensor that measures a distance between a paste discharge port of the nozzle and the surface of the substrate, Providing control means for adjusting the distance between the paste discharge port of the nozzle and the surface of the substrate according to the output of the sensor,
Control means, when the change amount of the output of the distance sensor is within the threshold for the set value of the distance between the paste discharge port and the substrate surface of the nozzle, the paste discharge port of the nozzle and the substrate surface Is adjusted to a predetermined value specified in advance, and when the amount of change in the output of the distance sensor deviates from the threshold value, the interval between the paste discharge port of the nozzle and the surface of the substrate is set to the immediately preceding value. A paste applicator characterized by having a comparative adjustment section for fixing.