JPH09309057A - Foreign matter corrector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intermittently wind a polishing tape, by providing a polishing tape supply part driving the polishing tape wound by a stepping motor. SOLUTION: In an X-axis table 6, a Z-axis table 9 driven by a Z-axis drive unit 8 is provided, in addition, in the Z-axis table 9, an X'-axis table 10 swiveled by a short stroke in the same direction to an X-axis is mounted. This X'-axis table 10, also similarly to the other table, is driven by an X'-axis drive unit 11. The X'-axis table 10, provided with a tape feed mechanism 14 comprising a polishing head and tape reels 13, 13' driven by a stepping motor, is formed in a mechanism winding a polishing tape 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign matter correcting device, for example, a foreign matter correcting device for removing foreign matter such as metal powder adhered to the surface of a color filter used in a color liquid crystal display device by polishing.

[0002]

2. Description of the Related Art A color liquid crystal display device is provided with a pair of glass substrates, one of which is called a color filter substrate. This color filter substrate is composed of color filters of three primary colors of red, green and blue by a pigment dispersion method or a printing method. In the step of applying this color filter or the step of coating the next protective film, metal powder, particles, etc. may sometimes be mixed. As a result, problems such as short-circuiting with the other substrate and uneven display occur. Since these foreign matters are under the color filter or the protective film, the portion thereof has a projecting shape, and in order to correct this so as to have a smooth surface, for example, Japanese Patent Laid-Open No. 7-205011, Japanese Patent Laid-Open No. 5-77153 proposes a method of correcting with a polishing tape.

[0003]

In order to correct with a polishing tape, the height of the foreign matter should be sufficient so as not to damage the color filter surface other than the protrusions or to affect the thin film formation in the subsequent process. It is required to be low. To this end, a partial polishing method that polishes only foreign matter is used, and the position control accuracy in the height direction (Z direction) is increased so that the height of the foreign matter after correction is as close as possible to the height of the surrounding surface. Is desired.

The above-mentioned proposed methods all perform partial polishing and height control. However, the height control is only performed by positioning the polishing portion on the basis of the Z-direction sensor or by moving in the Z-direction by a predetermined amount. Then, since the polishing tape is continuously fed at this position, if the thickness of the tape varies, the polishing height fluctuates by the variation.

The variation in tape thickness is ± 5% when using a polyester film-based polishing tape.
(For example, when the thickness is 70 μm, it is about ± 3.5 μm), which is not negligible with respect to the height (2 to 6 μm) in which the liquid crystal is sealed. For example, even if the height after polishing is set to 2.5 μm, the thickness may be −1 to 6 μm when the variation in tape thickness is not taken into consideration, which may damage the color filter surface, The polishing may not be sufficiently low. The same thing occurs when there is variation in the degree of tape adhesion of the polishing head.

Therefore, a main object of the present invention is to provide a foreign matter repairing device which improves the adhesion of the tape to the polishing head and reduces the required tape amount.

[0007]

The invention according to claim 1 is
A foreign matter correction device for removing foreign matter on a work by swinging a polishing tape, the base stand for adsorbing and fixing the work, an XY stage moving in the XY axis directions on the base stand, and an XY stage The Z stage, which is installed on the top and can move vertically with respect to the work, and the polishing tape are supplied.
A swinging mechanism that includes a polishing tape supply unit for winding and a processing head unit and that makes a minute movement parallel to the work surface,
The polishing tape supply unit includes a moving mechanism that relatively moves the work and the polishing head in XY directions, and the polishing tape supply unit is configured to drive and wind the polishing tape by a stepping motor.

The invention of claim 2 further includes a non-contact sensor which is provided on the Z stage and measures the distance between the polishing head and the work surface.

The invention of claim 3 further includes a thickness measuring mechanism for measuring a variation in thickness of the polishing tape.

The invention of claim 4 further includes control means for controlling the height position of the swinging mechanism with respect to the work surface based on the measured value of the non-contact sensor and the measured value of the thickness measuring mechanism.

In the invention according to claim 5, the rocking mechanism according to claim 1 intermittently performs the tape feeding during polishing in synchronization with the height control.

In the invention according to claim 6, the position of the polishing tape according to claim 2 is selected at the displacement amount detection position by the non-contact sensor or in the vicinity thereof.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing an embodiment of the present invention, in which (a) shows a plan view and (b) shows a front view.

In FIG. 1, an adsorption groove 2 for fixing a color filter substrate as a work is formed on a base 1, and on the same plane as the surface of the base 1,
A guide rail 4 for the Y-axis table 3 is installed. The Y-axis table 3 is positioned by a Y-axis drive unit 5 including a ball screw and a motor.

On the other hand, the Y-axis table 3 has an X-axis table 6
Are installed, and both form a gate-shaped XY table. Like the Y-axis table 3, the X-axis table 6 is also positioned by an X-axis drive unit 7 including a ball screw and a motor.

The fact that the base 1 and the table guide are on the same plane is for facilitating processing and for obtaining a highly accurate plane. Further, by arranging the gate-type XY stage on the fixed base 1, it is possible to make a compact device as compared with a two-stage XY table configuration.

The X-axis table 6 includes a Z-axis drive unit 8
Is provided with a Z-axis table 9, and the Z-axis table 9 is further equipped with an X'-axis table 10 that swings in a short stroke in the same direction as the X-axis. The X'-axis table 10 is also driven by the X'-axis drive unit 11 like other tables. The X'axis table 10 is provided with a polishing head 12 and a tape feeding mechanism 14 composed of tape reels 13 and 13 'driven by a stepping motor (not shown), and is a mechanism for winding the polishing tape 15.

FIG. 2 is a diagram showing the outline of the polishing tape.
FIG. 3 is a diagram showing an example of abrasive grain size and count.

As shown in FIG. 2, the polishing tape has a thickness of 25.
As the polymer film 29 of .about.75 .mu.m, an abrasive grain 30 of aluminum oxide, silicon carbide, chromium oxide or the like having a grain size of 0.3 to 1 .mu.m shown in FIG.

FIG. 4 is an enlarged view of the polishing head, and FIG. 5 is a view showing a brake mechanism provided in the tape feeding mechanism 14.

A spherical projection 16 is provided at the tip of the polishing head 12 as shown in FIG.
5 comes into contact with the protrusion 16 and is wound up. Clamping mechanisms 17 and 17 'are arranged on both sides of the protrusion 16 and are used when polishing the tape in a fixed state. A brake mechanism 33 as shown in FIG. 5 is provided on the shaft 32 of the tape reel 13. The brake mechanism 33 is for giving the polishing tape a tensile strength of, for example, 6.5 kg or less and a back tension on the winding side. The brake mechanism 33 generates a rotation resistance on the shaft, and the polishing tape 15 is sufficiently adhered to the protrusion 16.

Therefore, the brake mechanism 33 is mounted on the hub 34 so as to be integrated with the tape reel shaft 32.
And the tape feed mechanism 14 so that it does not rotate with the hub.
The tape reel shaft 32 has a rotational resistance due to the friction between the hub 34 and the friction plate 36. Rotational resistance can be freely adjusted by changing the frictional resistance between the hub 34 and the friction plate 36 by expanding and contracting the coil spring 37.

FIG. 6 is a view showing a tape thickness measuring mechanism. This tape thickness measuring mechanism measures the amount of change in the thickness of the tape and uses an amount commensurate with this to control the Z-axis direction. The tape thickness measuring mechanism 20 includes a Z′-axis guide portion 21, an air cylinder 22, a spring 23, and an air microsensor 24. The polishing head 12 can be freely stroked up and down by the Z'-axis guide portion 21 and the spring 23, and the air microsensor 24 is used as the polishing head 12.
It is fixed at one end. This air micro sensor 24
The distance from the upper surface of the glass substrate is measured by. In addition,
Although this sensor is an air micro, other than this, any non-contact sensor such as a capacitance sensor or a sensor using reflection of light may be used.

The output from the air microsensor 24 is given to the control device 26 via the amplifier 25. The control device 26 performs necessary calculation for control based on the output of the air micro sensor 24, and Z
A positioning command signal is output to the axis drive unit 28. The Z-axis drive unit 28 drives the Z-axis according to the command.

FIG. 7 is a diagram showing a state in which the height is measured by using an air microsensor in the vicinity of the projection foreign matter, and FIG. 8 is a diagram showing a calibration curve of the air microsensor.

Next, a method of correcting the protrusions existing on the color filter substrate will be described with reference to FIGS. First, when the color filter substrate is installed on the base 1, the tape feeding mechanism 14 causes the polishing tape 15 to move.
Is wound by a fixed amount and fixed by the clamp mechanisms 17 and 17 '. In this state, the polishing head 12 is released in the vertical direction by releasing the air cylinder 22, and is moved to an appropriate position on the color filter substrate (for example, the outside of the display unit) so as to be in contact with the substrate. In the Z direction.

FIG. 7A shows a state in which the polishing tape 15 is in contact with the color filter substrate. In this state, the distance a to the color filter is measured by the micro sensor 24. Next, the air cylinder 22 is operated to operate the polishing head 1.
Press 2 down to secure. Then, after lowering the Z stage to a height that does not contact the substrate, the X axis table 6 and the Y axis table 3 are driven to move the polishing head 12 to the position of the protruding foreign matter. FIG. 7 shows a state when the height is measured using the air microsensor 24 in the vicinity of the projection foreign matter.
(B). Assuming that the distance to the color filter substrate at this time is b, (ba) is the distance from the current polishing tape position to contact with the color filter substrate.

The position at which the film is actually stopped is generally slightly above (1 to 2 μm) above the position in contact with the color filter substrate in order to allow for errors in measurement or control. The relationship between the output of the air microsensor 24 and the height is measured in advance using a calibration curve as shown in FIG. A command value for lowering the Z axis is calculated based on this calibration value.

The advantage of polishing by such a method is that
Even if there is a change in tape thickness, each time polishing is performed,
Since the value of a is measured, its influence can be eliminated. Further, since the distance b to the substrate is measured in the vicinity of the presence of the protrusion, it is possible to eliminate the influence of the thickness variation of the substrate. Furthermore, since these are measured immediately before polishing, even if there is temperature drift of the sensor, expansion and contraction in the Z direction due to the temperature of each part of the mechanical part, etc., the error is corrected and the height is controlled. Therefore, the height can be controlled with high accuracy.

During polishing, the polishing tape 15 is fixed by the clamp mechanisms 17 and 17 ', and the polishing head 12 descends in the Z-axis direction while being slightly vibrated (several mm) by the X'-axis. Every time the polishing tape 15 swings a fixed number of times, the winding reel 13 is driven by the stepping motor to be wound, and the polishing tape 15 is repeatedly swung and polished again with new abrasive grains. The intermittent movement is because the fixing of the polishing tape 15 allows the spherical surface of the polishing head 12 to be in close contact with the polishing tape 15, and the winding is performed when the type of the projection foreign matter, for example, the metallic foreign matter is mixed. This is to prevent the grains from falling off. However, it is desirable that the winding length is such that the thickness fluctuation is sufficiently small (within several cm from the thickness measurement position).
Further, the winding timing is synchronized with the height control or the X'-axis control, such as when the projection foreign matter is not being polished, that is, immediately after feeding a fixed amount in the height direction or after swinging to the moving end in the X'direction. Is desirable.

[0031]

As described above, according to the present invention, the polishing tape is driven and wound by the stepping motor each time the work is polished by the polishing tape.
The polishing tape can be wound up intermittently, and the amount of tape that requires protrusion correction can be reduced compared to the conventional method. Further, by combining with the swinging mechanism, it is possible to eliminate the influence of variations in the thickness of the tape.

[Brief description of drawings]

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

FIG. 2 is a diagram schematically showing a cross section of a polishing tape.

FIG. 3 is a diagram showing an example of abrasive grain sizes and counts of a polishing tape.

4 is an enlarged view of the polishing head shown in FIG.

FIG. 5 is a cross-sectional view showing a brake mechanism.

FIG. 6 is a view showing a tape thickness measuring mechanism.

FIG. 7 is a diagram showing a state in which a height is measured using an air microsensor in the vicinity of a projection foreign matter.

FIG. 8 is a diagram showing a calibration curve of a sensor.

[Explanation of symbols]

 1 base table 2 suction groove 3 Y-axis table 4 guide rail 5 Y-axis drive unit 6 X-axis table 7 X-axis drive unit 8 Z-axis drive unit 9 Z-axis table 10 X'-axis table 11 X'-axis drive unit 12 polishing head 13, 13 'Tape reel 14 Tape feed mechanism 15 Polishing tape 16 Protrusion 17, 17' Clamp mechanism 20 Tape thickness measuring mechanism 21 Z'axis guide 22 Air cylinder 23 Spring 24 Air micro sensor 25 Amplifier 26 Controller 27 Driver 28 Z Axial drive unit 32 Tape reel shaft 33 Brake mechanism 34 Hub 35 Flange 36 Friction plate 37 Coil spring

Claims (6)

[Claims] 1. A foreign matter correction device for removing foreign matter on a work by swinging a polishing tape, comprising: a base table for adsorbing and fixing the work; A movable Z stage, a polishing tape supply unit for supplying and winding the polishing tape, and a polishing head unit, and a swinging mechanism that makes a minute movement parallel to the work surface, the work and the A foreign matter correcting device, comprising: a moving mechanism that relatively moves the polishing head in the XY directions, and the polishing tape supply unit drives the polishing tape by a stepping motor to wind the polishing tape. 2. Further provided on the Z stage,
The foreign matter correction device according to claim 1, further comprising a non-contact sensor that measures a distance between the polishing head and the work surface. 3. The method according to claim 1, further comprising a thickness measuring mechanism that measures a thickness variation of the polishing tape.
Or the foreign matter correction device of 2. 4. A control means for controlling the height position of the swinging mechanism with respect to the work surface based on the measurement value of the non-contact sensor and the measurement value of the thickness measuring mechanism. The foreign matter correction device according to claim 2 or 3. 5. The swinging mechanism intermittently feeds a tape during polishing in synchronization with height control.
The foreign matter correction device according to claim 1. 6. The foreign matter correcting device according to claim 2, wherein the position of the polishing tape is selected at a displacement amount detection position by the non-contact sensor or in the vicinity thereof.