JP2004067369A - Method of controlling separation charge of plate-like member and separation charge control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a separation charge upon moving a plate-like member from a placing part. <P>SOLUTION: A plurality of conductive diaphragms 17 are provided in parallel. Each of the diaphragms 17 is formed to be a long rectangular flat plate-like shape narrower than the width of a glass substrate 12. The glass substrate 12 is jointly supportable or levitatingly maintainable by the diaphragms 17. Each of the diaphragms 17 are earthed. Upon moving the glass substrate 12 placed in a temporarily state from the diaphragms 17, the diaphragms 17 are excited to cause ultrasonic waves, and the glass substrate 12 is levitated over the diaphragms 17 with a predetermined space in between using radiation pressure of sound waves. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for suppressing peeling charge of a plate-like member, and more particularly, to a method of removing a plate-like member such as a glass substrate of a liquid crystal panel or a semiconductor wafer from a mounting table. The present invention relates to a method and a device for suppressing peeling charge of a plate-like member, which suppresses electrostatic charging due to charging.
[0002]
[Prior art]
When the two objects come into contact with each other, at the contact interface, a part of the charge carrier that has moved once returns to its original position, and the part remaining on the surface becomes static electricity. Charge transfer at the time of contact is a universal phenomenon that occurs not only in insulators but also in metals that are conductors. Therefore, even if a metal is held by an insulator and contacted or separated, it is charged.
[0003]
In a liquid crystal panel manufacturing process or a semiconductor device manufacturing process, it is necessary to transport a plate-shaped member such as a glass substrate or a semiconductor wafer between a plurality of processes, and move the plate-shaped member from a mounting portion on which the plate-shaped member is temporarily mounted. In this case, peeling charging occurs. When the plate member is moved simply by being placed on the placement portion, the amount of electrostatic charge due to peeling charge is small. However, in a process in which static electricity is likely to be generated, such as a rubbing process or a bonding process, which is one of the liquid crystal panel manufacturing processes, when the plate member is moved from the mounting portion, the amount of charge due to peeling charging increases, It was necessary to provide a static eliminator such as an ionizer.
[0004]
[Problems to be solved by the invention]
However, in the antistatic measures for removing static electricity charged by the peeling charge using a static eliminator such as an ionizer, the static electricity charged by the peeling charge is removed or neutralized, but the peeling charge is not prevented or suppressed. The charge amount of the peeling charge increases as the peeling speed increases. Therefore, in order to reduce the charge amount, it is necessary to reduce the peeling speed, that is, the speed at which the plate-like member is lifted from the mounting portion, so that the tact time is lengthened and the productivity is reduced.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and a first object of the present invention is to suppress peeling charge of a plate-like member when the plate-like member is moved from a mounting portion. It is an object of the present invention to provide a method, and a second object of the present invention is to provide an apparatus for suppressing peeling charge.
[0006]
[Means for Solving the Problems]
In order to achieve the first object, according to the first aspect of the present invention, when the plate member temporarily placed is moved from the conductor-made placing portion, the placing portion is excited. The plate-like member is levitated from the placement section by utilizing the radiation pressure of the sound wave generated by this.
[0007]
In the present invention, when the plate-shaped member temporarily placed on the conductor-made mounting portion is moved from the mounting portion, sound waves are generated by exciting the mounting portion, and the plate-shaped member is It floats from the receiver due to the radiation pressure of the sound waves. Sound waves are uniformly generated from the mounting portion, and the plate-like member is in a state of maintaining a constant gap from the mounting portion made of a conductor. As a result, peeling charging is suppressed. In addition, since the mounting portion is made of a conductor, grounding is easy, and static electricity is easily prevented.
[0008]
According to the second aspect of the present invention, the mounting portion on which the plate-shaped member can be temporarily mounted is excited by a vibrating plate made of a conductor by exciting means, and the plate-shaped member is radiated by a sound pressure from the vibration plate. Was constituted by an object levitation device for floating from the surface of the diaphragm, and the diaphragm was grounded.
[0009]
According to the present invention, when the plate-shaped member is moved from the mounting portion, the object levitation device is operated, and the diaphragm made of a conductor is excited. Then, the plate-like member floats while maintaining a constant gap from the surface of the diaphragm by the radiation pressure of the sound wave from the diaphragm. As a result, peeling charging is suppressed. Further, since the mounting portion is made of a conductor and grounded, it is easy to suppress the generation of static electricity.
[0010]
According to a third aspect of the present invention, in the second aspect of the invention, a plurality of the diaphragms are provided, and each diaphragm lifts the plate-like member placed on the diaphragm from the surface of the diaphragm. At this time, it is configured to be movable so as to keep the distance between each diaphragm and the plate member constant in accordance with the bending of the plate member.
[0011]
When the plate-like member is easily bent like a thin glass substrate having a large area, it is difficult to levitate the plate-like member with a certain gap from the diaphragm with one diaphragm. In the present invention, since each of the plurality of diaphragms is configured to be movable so as to maintain a constant distance from the plate member in the floating state, even a member in which the plate member is easily bent, The gap with the diaphragm is kept constant, and peeling charging is suppressed.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
An embodiment in which the present invention is embodied in a manufacturing process of a liquid crystal panel will be described below with reference to FIGS. FIG. 1A is a schematic perspective view of a partly omitted antistatic device, and FIG. 1B is a schematic side view of a partly omitted antistatic device.
[0013]
As shown in FIG. 1A, the peeling and charging prevention device 11 includes an object levitation device 13 functioning as a mounting portion on which a glass substrate 12 (shown by a chain line) as a plate-like member can be temporarily mounted. I have. The object levitation device 13 is provided on a horizontally disposed support plate 14.
[0014]
A vibrator 15 constituting the object levitation device 13 is fixed to the support plate 14, and the vibrator 15 is connected to a conductive diaphragm 17 via a horn 16. A plurality of (two in this embodiment) diaphragms 17 are arranged in parallel, and each of the diaphragms 17 is formed in a long rectangular flat plate shape narrower than the width of the glass substrate 12 and supports or supports the glass substrate 12 together. It can be levitated and held. Each diaphragm 17 is grounded.
[0015]
The vibrating plate 17 is fixed to the horn 16 excited by the vibrator 15 at both ends. Horn 16 is fastened to diaphragm 17 by screws 18 at its tip. The horn 16 is formed in a flat, substantially rectangular parallelepiped shape, and a frusto-conical cone 16a is integrally fixed to the lower surface thereof, and is attached to the diaphragm 17 in the vicinity of its longitudinal end in a state orthogonal to the longitudinal direction. Have been. The cone 16 a is fixed to the vibrator 15 on the surface opposite to the surface fixed to the horn 16. The tip surface of the horn 16 is formed in a plane orthogonal to the axial direction of the vibrator 15, and the horn 16 and the central axis of the vibrator 15 are arranged in a state of extending in the vertical direction. 1 (a) and 1 (b), the horn 16, the cone 16a and the vibrator 15 are drawn ignoring the size ratio.
[0016]
As the vibrator 15, a so-called Langevin type vibrator is used, and includes a pair of ring-shaped piezo elements 19a and 19b as shown in FIG. A ring-shaped electrode plate 20 is disposed between the piezo elements 19a and 19b, and the metal blocks 21a and 21b that are in contact with the surfaces of the piezo elements 19a and 19b that are opposite to the side that contacts the electrode plate 20 are bolted by bolts (not shown). The vibrator 15 is configured by tightening and fixing. The bolt is screwed into a screw hole (not shown) formed in the metal block 21a from the metal block 21b side. Both metal blocks 21a and 21b are in a state where they are electrically connected to each other via bolts. A flange 22 is formed in the metal block 21a, and the metal block 21a is fixed to the support plate 14 at the flange 22 by bolts (not shown) in a state fitted in holes (not shown) formed in the support plate 14. .
[0017]
The vibrator 15 is connected to the oscillator 23. The electrode plate 20 is connected to the oscillator 23 via the wiring 24a, and the ground terminal of the oscillator 23 is connected to the metal block 21b via the wiring 24b. The horn 16, the cone 16a, the vibrator 15, and the oscillator 23 constitute an exciting unit for exciting the diaphragm 17. In FIG. 1A, the illustration of the oscillator 23 connected to the one vibrator 15 is omitted.
[0018]
Next, the operation of the device configured as described above will be described.
The anti-peeling antistatic device 11 is provided as a mounting part in a process where static electricity is easily generated, such as a rubbing process or a bonding process. When the rubbing process or the bonding process is performed, the driving of the excitation unit is stopped, and the glass substrate 12 is supported in a state of being in contact with the vibration plate 17.
[0019]
When the glass substrate 12 is moved from the mounting portion, that is, above the vibration plate 17, the excitation means is driven. That is, the oscillator 23 is driven, the vibrator 15 is excited at a predetermined resonance frequency (for example, about 20 kHz), the horn 16 is longitudinally vibrated, and the diaphragm 17 is excited via the horn 16 to perform bending vibration. A standing wave is generated. Then, as shown in FIG. 2A, the glass substrate 12 supported (held) in contact with the vibration plate 17 is moved to the state shown in FIG. As shown, it floats from the surface of the diaphragm 17. The levitation distance is, for example, 100 to 300 μm, and the distance between the glass substrate 12 and the diaphragm 17 is exaggerated in FIG. 2B.
[0020]
When two objects in contact are separated from each other, peeling charging generally occurs. In the case of the glass substrate 12 as well, when one end of the glass substrate 12 is manually separated from the diaphragm 17 (peeled), a large charge is charged on the glass substrate 12. On the other hand, when the glass substrate 12 is separated from the diaphragm 17 by operating the object levitation device 13, the potential slightly increases, but the amount of the rise is manually adjusted by holding one end of the glass substrate 12 and It decreases to nearly 1/10 of the case where it is attempted to move away from the camera. The state is shown in the graph of FIG.
[0021]
As shown in FIG. 3, when the glass substrate 12 was simply separated from the diaphragm 17 (shown by a broken line), the potential rose to near 400 V in a short time and then dropped. On the other hand, when peeled off by ultrasonic levitation (shown by a solid line), the potential slightly increased, but was saturated at a low potential. Although the reason for this is not clear, the gap between the glass substrate 12 and the diaphragm 17 is kept constant in the sound wave levitation, and the gap is small, so that the glass substrate 12 and the diaphragm 17 are separated as shown in FIG. It is considered to function like a capacitor and balance.
[0022]
This embodiment has the following effects.
(1) When the plate-like member (glass substrate 12) temporarily placed is moved from the mounting portion (diaphragm 17) made of a conductor, the diaphragm 17 is excited to generate ultrasonic waves. Then, the glass substrate 12 is levitated from the vibration plate 17 using the radiation pressure of a sound wave. Therefore, the glass substrate 12 is kept in a state where a certain gap is maintained from the vibration plate 17 by the action of the sound wave from the vibration plate 17, and peeling charging is suppressed.
[0023]
(2) Since the diaphragm 17 is made of a conductor, it is easy to ground and the static electricity is easily prevented.
(3) The glass substrate 12 is instantly levitated from the diaphragm 17 by the action of ultrasonic waves, so that the tact time is shortened and the productivity is improved.
[0024]
(4) Since a long diaphragm 17 is used as the diaphragm 17, the number of the diaphragms 17 can be reduced as compared with a configuration using a large number of short diaphragms, and each diaphragm 17 is grounded. Work becomes easy.
[0025]
(5) When the glass substrate 12 is moved from the mounting portion after the rubbing process, the separation and charging can be suppressed by using the anti-peeling device 11 as the mounting portion in the rubbing step of the liquid crystal panel manufacturing process.
[0026]
(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. In this embodiment, when a plate-like member placed on a diaphragm is levitated from the surface of the diaphragm, the distance between each diaphragm and the plate-like member is kept constant corresponding to the bending of the plate-like member. The point that the plate-shaped member is configured to be movable as described above is greatly different from the above-described embodiment. The same parts as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0027]
FIG. 5A is a schematic side view showing a state where the vibrator 15 is supported, and FIG. 5B is a schematic plan view in which the diaphragm 17 is not shown. FIGS. 6A to 6C are schematic diagrams illustrating the operation.
[0028]
As shown in FIGS. 6A to 6C, in this embodiment, three sets of diaphragms 17 are provided, the center diaphragm 17 is vibrated at a predetermined position, and both sides of the center diaphragm 17 are sandwiched. Is provided movably in order to make it possible to adjust the distance and the angle formed with the central diaphragm 17. Each diaphragm 17 is grounded.
[0029]
As shown in FIGS. 5A and 5B, a vibrator 15 supporting a movable diaphragm 17 is a movable body 26 movable along a pair of guide rails 25 fixed on the support plate 14. Fixed to. The guide rail 25 is disposed so as to extend in a direction orthogonal to the longitudinal direction of the diaphragm 17 (perpendicular to the plane of FIGS. 5A and 5B), and the upper surface thereof is held in a state where the glass substrate 12 floats. At the time of bending. A hole 14 a is formed in a portion of the support plate 14 sandwiched between the guide rails 25 to allow the vibrator 15 to move together with the moving body 26. The moving body 26 includes wheels 26 a that roll on the guide rail 25. The moving body 26 is connected to a plunger 28 of a linear actuator 27 fixed on the support plate 14, and is moved along the guide rail 25 by driving the linear actuator 27. The connection between the moving body 26 and the plunger 28 employs a configuration (for example, a combination of a pin and a long hole) that allows the moving body 26 to move vertically relative to the plunger 28.
[0030]
In this embodiment, when the glass substrate 12 is levitated from the state in which the glass substrate 12 is in contact with the vibration plate 17 as shown in FIG. 6A, first, each vibration plate 17 is excited and FIG. As shown, the glass substrate 12 is levitated from the surface of the diaphragm 17. When the glass substrate 12 is large and thin, the glass substrate 12 bends due to its own weight, and the distance between the glass substrate 12 and the diaphragm 17 becomes inconsistent. To avoid this, each linear actuator 27 is immediately driven from the state of FIG. 6B, and the moving body 26 is moved to a predetermined position. Then, as shown in FIG. 6C, the vibrator 15 is moved together with the vibration plate 17 to a predetermined position where the distance from the glass substrate 12 is constant in accordance with the bending of the glass substrate 12. As a result, even when the glass substrate 12 bends, the distance (gap) between the glass substrate 12 and the diaphragm 17 can be kept constant, and peeling charging can be suppressed. 6A to 6C, illustration of the support plate 14, the guide rail 25, and the like is omitted.
[0031]
This embodiment has the following effects in addition to the same effects as (1) to (5) of the above embodiment.
(6) A part of the vibrating plate 17 is configured to be movable together with the vibrator 15 so as to keep the gap with the glass substrate 12 constant in response to the bending of the glass substrate 12. Accordingly, even in the case of the glass substrate 12 which is large and thin and is likely to bend, peeling charge is effectively suppressed.
[0032]
The embodiment is not limited to the above, and may be configured as follows, for example.
The diaphragm 17 constituting the object levitation device 13 is not limited to a long one, and a short diaphragm may be used. However, when supporting the glass substrate 12 having the same area, the number of the long diaphragms 17 may be smaller, and the trouble of grounding the diaphragm 17 is simplified.
[0033]
In the case where the area of the diaphragm 17 is large and the plate-like member is small, the diaphragm 17 itself plays a role of grounding without necessarily grounding the diaphragm 17.
In the case where the glass substrate 12 is thin and large and easily bendable as in the second embodiment, the glass substrate 12 is levitated and held in an upwardly convex state instead of being levitated and held in a downwardly convex state. It is good also as a structure which performs.
[0034]
In order to keep the gap between the glass substrate 12 and the vibration plate 17 constant according to the bending of the glass substrate 12, the vibrator 15 is supported instead of moving the moving body 26 along the guide rail 25. The supporting member to be moved may be moved up and down by elevating means, and the vibrator 15 may be provided on the supporting member so as to be tiltable. Also in this case, the gap between the glass substrate 12 and the diaphragm 17 can be adjusted to a predetermined value by combining the elevation and the tilt.
[0035]
When the diaphragm 17 is grounded, it is not limited to a method in which the diaphragm 17 is directly connected to the ground via a wiring, but the support plate 14 or the frame of the antistatic device 11 may be made of a conductor and grounded through these.
[0036]
The plate member is not limited to the glass substrate 12, but may be another object, for example, a semiconductor wafer.
The width of the horn 16 supporting the long diaphragm 17 may not be the same as the width of the diaphragm 17 and may be wider or narrower than the width of the diaphragm 17, but is not less than the width of the diaphragm 17. Is preferred. When supporting a short diaphragm or a diaphragm such as a square, the horn may have a columnar or truncated cone shape.
[0037]
The fixing of the diaphragm 17 to the horn 16 is not limited to the fastening with screws, but may be performed by using an adhesive, or by using brazing or welding.
The vibrator 15 is not limited to the Langevin type vibrator, and another vibrator may be used.
[0038]
The invention (technical idea) grasped from the embodiment will be described below.
(1) In the first aspect of the invention, the mounting portion is grounded.
(2) In the invention according to any one of claims 1 to 3 and the technical idea (1), the diaphragm is formed to be long.
[0039]
(3) In the invention described in any one of claims 1 to 3 and the technical ideas (1) and (2), the plate member is a glass substrate.
(4) In the invention according to claim 3, the vibrator supporting the vibration plate is tiltably supported by a vertically movable supporting member by a lifting / lowering means, and a combination of the lifting and lowering of the supporting member and the tilting of the vibrator is combined. Thereby, the gap between the plate member and the diaphragm can be adjusted to a predetermined value.
[0040]
(5) The rubbing treatment is performed on the glass substrate using the peeling and charging suppressing device according to any one of claims 1 to 3 as a mounting portion, and then the glass substrate is levitated by a sound wave and mounted. Rubbing treatment method to move from the part.
[0041]
【The invention's effect】
As described above in detail, according to the first to third aspects of the present invention, peeling charging can be suppressed when the plate member is moved from the mounting portion.
[Brief description of the drawings]
FIG. 1A is a schematic perspective view of a peeling electrification suppressing device according to a first embodiment, and FIG. 1B is a schematic side view partially omitted.
FIG. 2A is a schematic diagram illustrating a state in which a glass substrate is placed on a diaphragm, and FIG. 2B is a schematic diagram illustrating a state in which the glass substrate floats.
FIG. 3 is a graph showing the relationship between time and potential when a glass substrate is separated.
FIG. 4 is a schematic diagram illustrating an operation.
FIG. 5A is a schematic side view of a main part of the second embodiment, and FIG. 5B is a schematic plan view of a main part.
6 (a) to 6 (c) are schematic side views for explaining the operation.
[Explanation of symbols]
12: a glass substrate as a plate-like member, 13: an object levitation device, 15: a vibrator constituting excitation means, 16: a horn, 16a: a cone, 23: an oscillator, 17: a diaphragm as a mounting portion .

Claims (3)

When moving the plate member temporarily placed from the mounting portion made of a conductor, the plate member is moved by utilizing a radiation pressure of a sound wave generated by exciting the mounting portion. A method for suppressing peeling electrification of a plate-like member floated from a mounting portion. A mounting portion on which the plate-like member can be temporarily placed is excited by a vibration plate made of a conductor by an exciting unit, and the plate-like member is levitated from the surface of the vibration plate by radiation pressure of sound waves from the vibration plate. A peeling electrification suppressing device which comprises an object levitation device and grounds the diaphragm. A plurality of the diaphragms are provided, and each of the diaphragms corresponds to a deflection of the plate-like member when the plate-like member placed on the diaphragm floats from the surface of the diaphragm. The peeling electrification suppressing device according to claim 2, wherein the device is configured to be movable so as to keep a distance from the shape member constant.

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