JP2006294602A - Destaticizing method, destaticizer, and antistatic method of glass substrate, and antistatic device of glass substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a destaticizing method and a destaticizer which carry out effective destaticizing to an insulator by a simple and efficient method. <P>SOLUTION: A hard X-ray generator 5 which irradiates hard X-rays from perpendicular direction on the front surface of an insulator 10 is provided. The hard X-ray generator 5 irradiates hard X-rays of 0.05Å or more and less than 1Å. The hard X-rays ionize the air on the front surface of the insulator 10 and destaticizes charges on the front surface of the insulator 10, and the transmission X-rays which have transmitted the insulator 10 destaticize the charges on the rear surface of the insulator 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a static elimination method for neutralizing an insulating substrate, a static elimination device, a glass substrate antistatic method, and a glass substrate antistatic device.

  Conventionally, in a manufacturing process of a glass substrate used for a liquid crystal display or the like, electrons are trapped in an incompletely bonded portion of atoms due to friction with a belt surface during conveyance or separation during separation by a vacuum chuck. . In addition, when the atoms are ionized, the insulating substrate may be positively or negatively charged.

  When the glass substrate is charged in this manner, there is a disadvantage that surrounding particles are adsorbed or dielectric breakdown of various thin films deposited on the substrate is caused. In addition, when a liquid crystal display is manufactured using a charged glass substrate, there is a problem that the rising voltage of the liquid crystal display changes due to the charge of the glass substrate and the brightness of the liquid crystal screen changes.

Therefore, as a method for removing electricity from an insulator such as a glass substrate, there are a method for removing electricity using corona discharge, a method for removing electricity using soft X-rays, and the like. The static elimination method using corona discharge is a method in which positive and negative ions are generated from the discharge electrode, and the charged charges are neutralized by spraying ions onto the glass substrate. Further, the static elimination method using soft X-rays (wavelength of 1 mm or more) is a method in which air in the vicinity of an insulator is ionized by soft X-rays and the charge of the insulator is neutralized by the ionized air. Patent Documents 1 to 5 disclose a method of removing electricity from an insulator using soft X-rays.
JP 11-214191 A JP 2000-267106 A JP 2002-257702 A JP 2004-299814 A Japanese Patent No. 2749202

  However, the static elimination method using corona discharge is not suitable for use in a clean environment because dust is wound up when ions are blown, and there is a problem of recombination of ionized air. There is a problem with performance.

FIG. 8 is a diagram for explaining a conventional static elimination method using soft X-rays.
As shown in FIG. 8A, it is possible to irradiate soft X-rays from the soft X-ray generator 5 # and ionize the air in the irradiation to neutralize the insulator.

  However, although soft X-rays have excellent ionization efficiency of air, since soft X-rays are easily absorbed by air, the distance from the insulator to the soft X-ray generation source cannot be taken. narrow.

  Further, when the glass substrate or the like is lifted from the stage or transported, peeling and triboelectric charging occur on the back surface of the glass substrate, and an instantaneous potential rises at the time of peeling. Therefore, in order to eliminate static electricity, an interval for sending ionized air between the glass substrate and the stage or an interval for irradiating soft X-rays is necessary.

  For example, as shown in FIG. 8B, with respect to the back surface of the glass substrate, in the lateral direction, specifically, the soft X-ray generator 5 # A on the right side and the soft X-ray generator 5 # B on the left side soft X In the case of irradiating a line, since there is a significant difference in ionization concentration at a position away from the vicinity of the soft X-ray tube that generates soft X-rays, there is a possibility that uneven discharge will result.

  Therefore, in order to eliminate static electricity unevenness and to remove static electricity over a large area such as a glass substrate, it is necessary to equip a large number of soft X-ray generators 5 # as shown in FIG. 8C, which is very expensive. In addition, time and cost are required for installation and maintenance.

  The present invention has been made to solve the above-described problems, and provides a static elimination method and a static elimination device that perform effective static elimination on an insulator in a simple and efficient manner. Objective.

  Another object of the present invention is to provide an antistatic method and an antistatic device for preventing the glass substrate from being charged when the glass substrate or the like is lifted from the stage or conveyed.

  The static elimination method according to the present invention directly irradiates a static elimination object charged with hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm.

  In another static elimination method according to the present invention, a hard X-ray generator that generates a hard X-ray having a wavelength of 0.05 mm or more and less than 1 mm is disposed at a position where the static elimination target can be directly irradiated, and the hard X-ray is applied to the static elimination target. Irradiate directly.

Preferably, the static elimination object corresponds to a glass substrate.
In particular, hard X-rays are directly irradiated from the vertical direction to the front surface of the charged glass substrate, and the back surface of the glass substrate is neutralized by hard X-rays transmitted through the glass substrate.

  In another static elimination method according to the present invention, a hard X-ray having a wavelength of 0.05 mm or more and less than 1 mm is directly irradiated from a top surface to a glass substrate placed in close contact with the upper surface of the installation table. To remove static electricity.

  In the method for preventing static electricity of a glass substrate according to the present invention, when lifting a glass substrate placed in close contact with the upper surface of the installation table, hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm from the vertical direction from the upper surface of the installation table. Irradiate directly.

  The static eliminator according to the present invention has a wavelength of 0.05 mm or more and less than 1 mm from the vertical direction from the upper surface of the installation table with respect to the installation table on which the glass substrate is installed and the glass substrate placed in close contact with the upper surface of the installation table. Irradiation means for directly irradiating hard X-rays.

  The antistatic device for a glass substrate according to the present invention has a wavelength 0. 0 from the vertical direction from the upper surface of the installation table when the installation table for installing the glass substrate and the glass substrate placed in close contact with the upper surface of the installation table are lifted. Directly irradiate with hard X-rays of at least 05 mm and less than 1 mm.

  The static elimination method and the static elimination apparatus according to the present invention irradiate the static elimination target with hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm. Since hard X-rays can ionize the gas in the vicinity of the static elimination object even when the distance to the static elimination object is increased, the static elimination area can be widened, and it is effective in a simple and efficient manner. Static charge removal can be performed.

  The antistatic method and the antistatic device according to the present invention directly irradiate hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm when the glass substrate is lifted. Hard X-rays have higher transmittance of the glass substrate than soft X-rays, so they can be neutralized with transmitted X-rays not only on the front side but also on the back side to prevent peeling and frictional charging. Can do.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

FIG. 1 is a schematic configuration diagram of a static eliminator 1 according to an embodiment of the present invention.
Referring to FIG. 1, a static eliminator 1 according to an embodiment of the present invention includes a hard X-ray generator 5, a grounded stage 15 that supports an insulator 10 that is a static eliminator, and a stage 15. A support member 20 made of plastic or the like that holds the insulator 10 at a distance d, a sensor 25, a surface potentiometer 30 that is connected to the sensor 25 and measures the surface potential of the insulator, and a data logger 35 And a control device (PC) 40. The sensor 25 is provided so as to measure the surface potential of the back surface of the insulator 10. The surface potential meter 30 measures the surface potential from the charge induced in the sensor 25 due to the charge generated in the insulator 10. Since the measurement of the surface potential is common, detailed description thereof is omitted.

  In addition, the space | interval of the distance Z is provided between the hard X-ray generator 5 and the insulator 10, and it arrange | positions in the position where a hard X-ray is directly irradiated from the perpendicular direction of the upper surface of the insulator 10. It shall be. The insulator 10 is charged. In this example, a glass substrate for liquid crystal display (hereinafter also referred to as an LCD glass substrate) or a glass substrate for plasma display (hereinafter also referred to as a PDP glass substrate) is used as an example of an insulator.

  The static elimination method according to the embodiment of the present invention eliminates static electricity by directly irradiating the insulator 10 with hard X-rays.

FIG. 2 is a configuration diagram of the hard X-ray generator 5 that generates hard X-rays.
Referring to FIG. 2, hard X-ray generation device 5 includes a control unit 100 that controls hard X-ray generation unit 50, and a hard X-ray generation unit 50 that generates hard X-rays based on instructions from control unit 100. including. The control unit 100 is connected to an external power source via the cable CB1, supplies a voltage necessary for driving the hard X-ray generation unit 50, and outputs a control signal for control. To do. The hard X-ray generation unit 50 includes a high-pressure generation unit 51, an X-ray tube cooling unit 52, an X-ray tube 53, and a protective case made of lead. The X-ray tube 53 includes a target 54 formed of a filament 54 and a metal material such as tungsten. The high-voltage generator 51 supplies a so-called filament current to the filament 54 of the X-ray tube 53 and applies a high voltage to the target 55 formed of a metal material such as tungsten. Along with this, thermoelectrons jump out of the target 55 from the filament 54 that is supplied with the filament current. X-rays are generated by colliding with the target 55. Hard X-ray generator 5 according to the present embodiment generates hard X-rays having a wavelength of 0.05 to 1 mm. This hard X-ray of 0.05 mm or more and less than 1 mm is a hard X-ray wavelength range that can be used when static elimination is actually performed on a glass substrate.

  The protective case 54 is provided with an opening hole, from which X-rays are irradiated to the outside. In addition, since 99% of the kinetic energy of the thermoelectrons jumping out from the filament 54 is converted into heat, the X-ray tube cooling unit 52 is used for cooling. As a cooling method, an air cooling method, an oil cooling method, or the like can be used.

FIG. 3 is a conceptual diagram illustrating a static elimination method according to the embodiment of the present invention.
Referring to FIG. 3, the static elimination method according to the embodiment of the present invention irradiates insulator 10 with hard X-rays (hard X-rays) from hard X-ray generator 5.

  The hard X-rays irradiated from the hard X-ray generator 5 are absorbed by air and generate ions. Along with this, ions generated in the vicinity of the insulator 10 react with the charged charges of the insulator 10 and are neutralized.

  Also, unlike soft X-rays, hard X-rays are irradiated directly onto the insulator, so that the insulator itself generates secondary electrons, secondary X-rays, and scattered X-rays depending on the atomic number of the insulator. Ionizes air near the body. Specifically, secondary X-rays, scattered X-rays, and secondary electrons are generated from transition elements, light elements, or heavy elements contained in the insulator by irradiation with hard X-rays. These also react with air to produce ions. The generated ions react with the charge charged on the insulator to neutralize. That is, the static elimination effect is further enhanced by secondary X-rays, scattered X-rays and secondary electrons in addition to hard X-rays.

  Moreover, since hard X-rays ionize insulator solid, the charge of an insulator is neutralized by solid ionization. That is, when hard X-rays pass through the glass substrate, the glass material is ionized and an effect of short-circuiting can be obtained. For this reason, the residual electric charge in a glass substrate can be removed.

  In particular, since hard X-rays according to the embodiment of the present invention have higher energy than soft X-rays, the hard X-rays are not easily absorbed by air, and the distance between the insulator and the hard X-ray generator is set between the insulator and soft X-rays. It is possible to take longer than the distance to the generator. Therefore, if the irradiation angles from the X-ray tube are equal, the irradiation area (static elimination area) becomes wider than the soft X-ray method.

  FIG. 4 is a diagram for explaining a comparison of static elimination times when an insulator is irradiated with soft X-rays and hard X-rays.

  As shown in FIG. 4, when the distance is short, soft X-rays have higher air absorption rate, so ions are effectively generated, and the charge removal time is executed in the same short period as that of hard X-rays. It is possible.

  However, as shown in FIG. 4, the longer the distance is, the soft X-rays are absorbed by the air at a short distance, so that the ratio of ions generated in the vicinity of the insulator decreases. It takes much longer than hard X-rays. For example, when the distance Z is about 1000 mm, the soft X-ray neutralization time is 6 seconds, whereas the hard X-ray neutralization time is 2 seconds. Therefore, in the case of the static elimination method using hard X-rays, a sufficient static elimination effect can be expected even when the irradiation range is widened.

  Furthermore, the hard X-rays irradiated from the hard X-ray generator 5 pass through the insulator. Accordingly, the hard X-rays that have passed through the front surface of the insulator react with the air on the back surface to generate ions. Since the air near the back surface of the insulator is ionized by the transmitted hard X-rays, the electric charge charged on the back surface of the glass substrate or the like is neutralized.

  That is, by irradiating hard X-rays only from one upper side of an insulator such as a glass substrate, not only the front surface of the insulator such as a glass substrate but also the back surface can be discharged simultaneously.

  Further, secondary X-rays, scattered X-rays, and secondary electrons are also generated for the hard X-rays irradiated on the back surface, and these also react with air to generate ions as described above. The generated ions react with the electric charges charged on the back surface of the insulator 10 and are neutralized.

  FIG. 5 is a diagram for explaining the transmittance of the glass substrate when irradiated with soft X-rays and hard X-rays.

  FIG. 5 (a) shows the X-ray intensity when no glass substrate is provided. Here, the distance Z of the X-ray generator is set to 200 mm.

  FIG. 5B shows a case where an LCD glass substrate is arranged and the transmittance is measured. Here, the thickness of the LCD glass substrate is about 0.7 mm.

In this case, since the soft X-ray has low energy, the transmittance of the LCD glass is extremely low.
FIG. 5C shows a case where a PDP glass substrate is arranged and the transmittance is measured. Here, the thickness of the PDP glass substrate is about 2.8 mm.

  Also in this case, since soft X-rays have low energy, the transmittance of PDP glass is extremely low, and only hard X-rays are measured.

  Since hard X-rays pass through LCD glass (0.7 mm), PDP glass (2.8 mm), etc., the back surface of the glass can be neutralized by transmitted X-rays transmitted through the insulator.

  If a secondary excitation plate that is likely to generate secondary electrons, secondary X-rays and scattered X-rays is disposed under the back surface of the insulator, the X-rays transmitted through the insulator hit the secondary excitation plate, and the secondary excitation plate Since the air around the back surface of the object to be neutralized is ionized by secondary X-rays, scattered X-rays, and secondary electrons generated from the excitation plate, more effective static elimination is possible.

  In addition, when the front surface of an insulator such as a glass substrate wetted with water after the cleaning process is charged, the front surface potential of the front surface of the insulator when soft X-rays are irradiated is 0V, but when the back surface potential of several tens to several hundred volts is generated by electrostatic induction on the back surface of the glass substrate, or when the soft X-ray irradiation is stopped, the front surface is 0V. There is a phenomenon such as the generation of an electric potential, and even if the surface of the glass is charged, there are cases where it is not possible to completely remove static electricity with soft X-rays due to the wet state.

  FIG. 6 is a diagram for explaining a case where the potential of the back surface is measured when the front surface of the glass substrate is irradiated with hard X-rays and soft X-rays. Here, the potential of the back surface is measured using the sensor 25 shown in FIG.

  As shown in FIG. 6, the static elimination time is substantially the same, but when static elimination is performed with soft X-rays, a potential of 21 V remains. Therefore, when neutralizing with soft X-rays, it is difficult to completely neutralize the charged glass substrate with respect to the front surface and the back surface. When neutralizing with hard X-rays, both the front and back surface potentials are 0 V, and can be completely neutralized.

  In particular, when hard X-rays are used, it is possible to neutralize the front and back surfaces of the glass regardless of the wet state of the glass.

  Then, when the glass substrate or the like is lifted from the stage or transported, peeling / friction charging occurs on the back surface of the glass substrate, and there is a possibility that the instantaneous potential increases at the time of peeling. In particular, when soft X-rays are used, residual charges remain, and when the glass substrate is in close contact with the stage, an interval for sending ionized air, or for irradiating soft X-rays. Although it is difficult to keep a gap, when using hard X-rays, transmission X-rays, secondary electrons, secondary X-rays and scattered X-rays are generated under the insulator back surface. It is possible to prevent frictional charging and suppress an instantaneous increase in potential on the glass substrate.

  That is, when the glass substrate is lifted from the stage or transported, the glass substrate is irradiated with hard X-rays to prevent the glass substrate from being peeled off or frictionally charged.

  FIG. 7 is a distribution diagram in the case where the metal material forming the glass substrate material is excited when the glass substrate is irradiated with X-rays.

  FIG. 7A shows an LCD glass substrate, and the metals Al, Si, Ca, Fe, and Sr forming the LCD glass substrate appear in ascending order of element numbers. Since the soft X-ray energy is up to about 10 keV, it cannot be excited with respect to the metal Sr.

  FIG. 7B shows a PDP glass substrate, and the metals Si, K, Ca, Fe, Sr, Zr, and Ba forming the PDP glass substrate appear in ascending order of element numbers. As described above, since the energy of the soft X-ray is 10 keV, the metals Sr, Zr, Ba excited by the energy after that cannot be excited.

  Therefore, by irradiating hard X-rays having a wavelength of less than about 1 mm (energy: 12.4 eV or more), secondary electrons, secondary X-rays, and scattered X can be applied to metals that cannot be excited by soft X-ray energy. As a result, a static elimination effect can be expected even more than soft X-rays. In consideration of the necessity for X-rays to reach the back surface in a PDP glass substrate having the smallest X-ray transmittance, the energy increases as the wavelength of X-rays becomes shorter and becomes larger including the shielding structure. The wavelength of the line is considered to be 0.05 mm or more.

  Since the static elimination method according to the embodiment of the present invention uses hard X-rays with high energy, compared with the case of using soft X-rays with low energy, the irradiation range is extended or the irradiation angle is widened to widen the irradiation range. Even so, it can be sufficiently neutralized. Therefore, it is possible to reduce the number of hard X-ray generators necessary for neutralizing a large-area insulator such as a glass substrate. Accordingly, maintenance and installation are facilitated, and the cost is reduced as a whole.

  In addition, a general X-ray tube that generates soft X-rays is provided with a beryllium window as an X-ray window material having good soft X-ray transmission efficiency. However, since beryllium is a hazardous substance, management from the safety and environmental aspects, including handling and recovery, is indispensable and care must be taken.

  On the other hand, since an X-ray tube that generates hard X-rays does not use harmful substances, it is advantageous from the viewpoint of safety and environment for handling and recovery.

  In addition, although it experimented by giving 40 kV as a high voltage applied to the tube voltage 53 in order to irradiate the hard X-ray demonstrated in said embodiment, and 0.6 mA as a filament current, it is not restricted to these numerical values, The same effect can be obtained by adjusting the numerical value according to the thickness of the insulator.

  In the above embodiment, it has been explained that it is possible to irradiate the hard X-ray from the vertical direction of the front surface of the glass substrate and neutralize the charge on the back surface by the transmitted X-ray. However, the present invention is not limited to this, and as shown in FIG. 8B, it is also possible to irradiate the back surface with hard X-rays by providing hard X-ray generators on the right and left sides. In this case, in the case of hard X-rays, since the effective irradiation distance is long as described above, neutralization of the back surface can be effectively executed without causing unevenness of static elimination. That is, it is possible to reduce the number of installed hard X-ray generators, and an economic effect associated with a reduction in installation cost and maintenance frequency can be expected.

  In the above description, LCD glass or PDP glass has been described as an example. However, the present invention is not limited to this. SED (Surface-conduction Electron-emitter Display), organic EL (organic electroluminescence display), FPD (Flat Panel Display) Alternatively, it can also be applied to various insulating materials such as copy paper, packaging / packaging materials, and static elimination of solids, liquids, and gases.

  Further, in the above example, the case where the irradiation distance is extended or the irradiation range is widened by widening the irradiation distance has been described. However, irradiation with a narrow bundle X-ray beam using a collimator, a slit, or a capillary is performed. It is also possible to apply the above-described static elimination method only to a desired area by narrowing the range to limit the static elimination area of solid, liquid or gas. Further, by controlling the beam spatially and temporally, it is possible to realize a wide variety of antistatic and static elimination methods according to the user's needs.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram of the static elimination apparatus 1 according to embodiment of this invention. It is a block diagram of the hard X-ray generator 5 which generate | occur | produces a hard X-ray. It is a conceptual diagram explaining the static elimination system according to the embodiment of the present invention. It is a figure explaining the comparison of the static elimination time at the time of irradiating an insulator with a soft X ray and a hard X ray. It is a figure explaining the transmittance | permeability of the glass substrate at the time of irradiating a soft X ray and a hard X ray. It is a figure explaining the case where the electric potential of the back surface at the time of irradiating the front surface of a glass substrate with a hard X ray and a soft X ray is measured. It is a distribution map when the metal material which forms glass substrate material when X-rays are irradiated to a glass substrate is excited. It is a figure explaining the static elimination method using the conventional soft X ray.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Static elimination apparatus, 5 Hard X-ray generator, 10 Insulator, 15 stage, 20 Support member, 25 Sensor, 30 Surface potential meter, 35 Data logger, 40 PC, 50 Hard X-ray generation unit, 51 High voltage generation part, 52 X-ray tube cooling unit, 53 X-ray tube, 54 filament, 55 target, 100 control unit.

Claims (8)

  A static elimination method for directly irradiating a charged static elimination object with hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm. A hard X-ray generator that generates hard X-rays with a wavelength of 0.05 mm or more and less than 1 mm is disposed at a position where the static elimination object can be directly irradiated,
The static elimination method which irradiates the said static X-ray directly to the said static elimination object.   The static elimination method according to claim 1, wherein the static elimination object corresponds to a glass substrate. The hard X-ray is directly irradiated from the vertical direction on the front surface of the charged glass substrate,
The static elimination method according to claim 3, wherein the back surface of the glass substrate is neutralized by the hard X-rays transmitted through the glass substrate.   A static elimination method for neutralizing a glass substrate placed in close contact with the upper surface of the installation table by directly irradiating hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm from the upper surface of the installation table from the vertical direction.   An antistatic method for a glass substrate, wherein when the glass substrate placed in close contact with the upper surface of the installation table is lifted, hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm are directly irradiated from the upper surface of the installation table from the vertical direction. An installation table on which a glass substrate is installed;
A neutralization device comprising: irradiation means for directly irradiating a hard X-ray having a wavelength of 0.05 mm or more and less than 1 mm from a vertical direction on the glass substrate placed in close contact with the upper surface of the installation table. . An installation table on which a glass substrate is installed;
An antistatic device for a glass substrate that directly irradiates hard X-rays having a wavelength of 0.05 mm or more and less than 1 mm from a vertical direction from the upper surface of the installation table when lifting the glass substrate placed in close contact with the upper surface of the installation table .

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