JP3080116B2 - Device for neutralizing charged articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neutralizing device for removing static electricity from articles at a high speed, and more particularly to a curtain air flow type static electricity removing device which is effective in removing electricity from large glass substrates in manufacturing liquid crystal substrates.

[0002]

2. Description of the Related Art In a field of manufacturing a liquid crystal panel, charging of a glass substrate is a major problem. In particular, in recent years, as the size of the substrate is increased and the element is miniaturized, a uniform and high-speed static elimination method for a large glass substrate is required.

In the manufacture of liquid crystal panels, there is a rubbing process in which a glass substrate is rubbed with a cloth (buff) in order to align the liquid crystal. However, the processed substrate is sparsely charged to a high potential due to its large size and insulating properties. . For example, a Corning glass substrate (Fusion 7059) is floated 10 mm from the conductor, and the surface is covered with cellulose wipers, rubber gloves, absorbent cotton, acrylic rollers, and hair rollers.
When the charge amount of the reciprocating rub was measured,
+ 1500V, -1000 to -2000V, -100 to -200V, +200 to
The result is +600 V, -1000 to -1500 V, and the potential ranges from 1 KV to 2 KV at high places.

When the glass substrate is charged in such a manner, floating particles adhere or electrostatic discharge occurs due to electrostatic force, which causes disconnection or short circuit of an element formed on the substrate, visual defects of an image element, and the like. The yield will be reduced.

Various ionizers utilizing corona discharge have been known as devices for removing charges from a charged article. JP-A-3-230499 and JP-A-3-230499 relating to the same applicant.
No. 230500, Japanese Patent Application Laid-Open No. 4-06897, Japanese Patent Application No. 3-94984
And Japanese Patent Application No. 3-174807 have proposed various AC ionizers capable of balancing the concentration of positive and negative ions generated.

In addition, in the proceedings of the Japan Society of Air Conditioning and Sanitary Engineering Academic Lectures (H3.10.31.-11.2. Announced a nozzle type ionizer that combines an air blowing nozzle and a corona discharge electrode.

Further, in order to solve the problem that the electrode is deteriorated at the time of discharge of the ionizer and metal particles are scattered and metal contamination occurs, the discharge electrode is coated with an insulating material, and metal corrosion caused from the exposed metal surface of the member is solved. The present inventors have proposed that the counter electrode is coated with Teflon in order to solve the problem, and has recently come into practical use as an advantageous static elimination facility in semiconductor manufacturing processes and the like.

[0008]

In the nozzle type ionizer proposed above, a metal discharge electrode covered with an insulating material is installed in a cylindrical nozzle having a gas blowing opening at the tip, and the cylindrical nozzle is provided with a gas discharge opening. A metal counter electrode covered with a resin is provided on the outside to neutralize a charged article. For this reason,
The airflow injected from the nozzle opening becomes a diverging radial,
Since the ions carried by this air current also spread radially, it is not necessarily suitable for evenly removing large static elimination articles with a large area, and a sufficient static elimination effect is expected for increasingly large liquid crystal substrates. Can not.

An object of the present invention is to solve this problem.

[0010]

According to the present invention, an air supply chamber connected to an air supply source and having a slit-shaped opening for forming a curtain airflow, and a plurality of corona discharge chambers connected to a high-voltage power supply are provided. And a discharge electrode, wherein the discharge electrode is connected to the slit-shaped opening at predetermined intervals along the longitudinal direction of the slit.
More specifically, the lower surface of the cylindrical air supply chamber is
A slit-shaped opening is provided along
-The interior is partitioned into an upper space and a lower space by a perforated plate.
When a supply port for introducing air from the air source to the upper space is provided
In both cases, the airflow introduced from the supply port into the upper space
After being rectified by the perforated plate and flowing into the lower space, the slit
It discharges from the mouth as a curtain airflow at a uniform speed in the width direction.
And a plurality of discharge electrodes for corona discharge.
At predetermined intervals along the longitudinal direction of the slit.
And ground the counter electrode connected to the DC power supply.
Device for neutralizing a charged article attached to the outside of a slot-shaped opening
I will provide a.

[0011]

According to the apparatus of the present invention, when the curtain airflow is discharged from the slit-shaped opening of the air supply chamber, positive or negative ions can be uniformly discharged from the discharge electrode into the curtain airflow. Therefore, the ionized curtain airflow can uniformly remove a charged article having a large surface area having a full width or a slightly smaller side length. In particular, in the case of a flat charged article, it is more effective to project the curtain airflow obliquely to the flat surface.

When a high AC voltage is applied to the discharge electrode,
Corona discharge occurs at the tip of the discharge electrode. At this time, as described in JP-A-3-230499 and JP-A-3-230500, even if the discharge electrode is covered with an insulating material, If an electrode (hereinafter, referred to as a counter electrode) is provided, corona discharge occurs. It is also known that corona discharge occurs even when the counter electrode is covered with a resin. As a result, the generation of fine particles from the discharge electrode during corona discharge can be avoided, and the corrosion of the counter electrode can be prevented from becoming a contamination source.

Positive and negative ions generated by the corona discharge are projected onto a charged object by riding on a curtain airflow. When the charged object is positively charged, negative ions are output. When the charged object is negatively charged, positive ions are output. Is neutralized by adsorption, and is neutralized.
Therefore, even large and large charged objects can be efficiently neutralized,
The static elimination ability increases as the wind speed of the discharge flow increases.

As the gas forming the curtain airflow, any kind of gas can be used as long as corona discharge occurs.
Air is most convenient for ease of use. If fine particles contained in the air adhere to the object to be neutralized and pose a problem, use clean air free of dust.

The neutralizing device of the present invention can be configured such that all members for forming a curtain airflow, including the discharge electrode and the counter electrode, have no metal surface. Thereby, it is possible to prevent the ionizer itself from being a source of dust of the metal particles.

[0016]

1 to 3 show an embodiment of a device for neutralizing a charged article according to the present invention. 1 is a discharge electrode to which an AC voltage is applied, and 2 is a counter electrode connected to the ground or a DC power supply. A plurality of discharge electrodes 1 are arranged at predetermined intervals along the longitudinal direction of the slit in the slit-shaped opening 3 with respect to a cylindrical air-supplying chamber 4 having a slit-shaped opening 3 for forming a curtain airflow. It is installed continuously.

More specifically, as shown in FIG. 2, a slit-like opening 3 having a narrow width is provided along the axial direction on the lower surface of a cylindrical air supply chamber 4 having a rectangular cross section orthogonal to the axis. On the other hand, a supply port 5 connected to an air supply source is provided on the upper surface of the gas supply chamber 4.
The space inside the air-supply chamber that reaches the slit-shaped opening 3 from above is divided into upper and lower parts.

The upper space 7 in the chamber, which is partitioned by the perforated plate 6, acts as an air supply plenum because the perforated plate 6 acts as a resistance to airflow, and the airflow introduced from the supply port 5 is rectified by the perforated plate 6. Then, the curtain airflow is discharged from the slit-shaped opening 3 at a substantially constant speed in the width direction.

A lead wire 9 extends in the lower space 8 along the axial direction. This lead wire has a metal conductor 11 inserted into a Teflon tube 10.
One end of each discharge electrode 1 is connected to the metal conductor 11 in a conductive relationship. In this case, each discharge electrode 1 is arranged so as to pass through the lead wire 9 substantially in the center of the slit-shaped opening 3, and in the example shown in the figure, its tip 12 projects slightly outward from the opening 3.

In this way, a large number of discharge electrodes 1 are arranged along the longitudinal direction of the slit at predetermined intervals, and each discharge electrode 1 is connected to ground or a DC power supply with a gap. Counter electrode 2 is attached. When connected to a DC power supply, by adjusting the applied voltage, the positive and negative ion concentrations can be balanced to prevent residual charge.

In the examples shown in FIGS. 1 to 3, the counter electrode 2 has a lattice shape as shown in FIG. 3, and the discharge electrode 1 is located at substantially the center of each lattice.

Gas supply port 5, cylindrical air supply chamber 4
In addition, all members for forming the curtain airflow, such as the slit-shaped openings 3, are made of resin (acrylic resin). The counter electrode 2 can also be covered with a resin. Thereby, the corrosion of the counter electrode 2 is prevented, and the corroded counter electrode 2 can be prevented from being a dust source of the metal particles.

FIG. 4 shows details of a discharge electrode 1 suitable for use in the apparatus of the present invention. The discharge electrode 1 has a needle-like metal electrode (tungsten electrode) 13 completely covered with an insulating material 14. As the insulating material 14, a tubular body made of quartz glass is used. More specifically, the holder 15
A needle-shaped electrode 13 is concentrically mounted in a quartz glass tube 14 having one end fixed to the other end, and the sealed end of the quartz glass tube 14 is also formed to have a sharpened point.
The three tips are in contact.

In the example shown in FIG. 4, the discharge end 12 of the discharge electrode covered with insulation is slightly projected outside the slit-shaped opening 3, and the counter electrode 2 is arranged so as to surround the projected portion.

The holder 15 is detachably attached to the Teflon tube 10 of the lead wire 9 via a screw.
The metal electrode 13 inside the discharge electrode is connected to the metal conductor 11 inside the lead wire through the Teflon tube 10.

The point that the discharge electrode 1 thus constructed is installed in an air supply device for forming a curtain airflow is the same as in the case of FIGS. 1 to 3, and the reference numerals in FIG. The same ones correspond to the same members. The needle electrode 13 may be used in an exposed state without being covered with the quartz glass tube 14. In addition, the needle electrode 13 itself may need to be replaced. For this reason, the member forming the slit is detachably connected to the main body of the air chamber 4 by a screwing member 16 so that the needle electrode 13 and the quartz glass tube 14 can be easily attached and detached.

FIG. 5 shows an example of the present invention having substantially the same structure as that of FIG. 4 except that the discharge end 12 is located in the slit-shaped opening 3. The reference numerals in FIG. 5 are as described above. In this example, since the discharge electrode 1 is hidden inside the slit-shaped opening 3, the amount of positive and negative ions generated by the corona discharge to be absorbed by the counter electrode 2 is reduced, and the charge removal efficiency is higher than that of FIG. Reference numeral 18 denotes a spacer for keeping the gap between the slit-shaped openings 3 constant even during ventilation. Of course, this spacer 18 can also be attached to the previous example. By arranging the spacers 18 in the slit at predetermined intervals, it is possible to prevent the slit width from being varied due to the pulsation of the curtain airflow.

6 to 8 show examples of the arrangement of the counter electrode 2. FIG. In the example of FIG. 6, a ring-shaped counter electrode 2 a is arranged around the position of each discharge electrode 1, and this ring-shaped counter electrode 2 a is connected to a common main lead 17. The main lead 17 is grounded or connected to a DC power supply.

In the example of FIG. 7, a parallel rod-shaped counter electrode is used in which two counter electrodes 2b are arranged so as to sandwich a row of discharge electrodes 1 therebetween. In the example shown in FIG. 8, when a grid-like counter electrode is formed around each discharge electrode 1, a counter electrode component 2C orthogonal to the slit is arranged to penetrate through the opening wall. Can be fixed to

In any case, the counter electrode 2 may be located upstream or downstream from the discharge end 12 of the discharge electrode 1. The counter electrode 2 is made of a conductive metal. As described above, a material whose surface is coated with a resin, for example, a material in which a stainless steel steel wire is inserted into a Teflon tube can be used. Such a counter electrode is used, and the discharge electrode 1 also has a structure in which a metal needle-like electrode is inserted into the quartz glass tube 14, and the lead wire 9 has a resin coating and forms a curtain airflow. By forming the entire blowout member of an insulating resin such as an acrylic resin, a neutralizing device having no exposed portion of the metal material can be configured.

According to the apparatus of the present invention configured as described above, when a high AC voltage is applied to the discharge electrode 1, an electric field is formed between the discharge electrode 1 and the counter electrode 2, and the discharge end 1 of the discharge electrode 1
2, a corona discharge occurs. In this case, since each discharge end 12 exists in the curtain airflow, the ion concentration in the discharged curtain airflow increases, and the ion concentration is distributed almost uniformly in the width direction of the curtain airflow.

At this time, if the discharge end 12 is inside the slit-shaped opening and the counter electrode is outside the slit-shaped opening, the number of ions absorbed by the counter electrode is reduced, so that the ion concentration in the curtain airflow is higher. Become. However, the discharge end 12
Even if is projected outside the slit-shaped opening, if the distance to the counter electrode 2 is sufficient, the amount of ions absorbed by the counter electrode 2 decreases, and if the speed of the discharge airflow is increased, a high ion concentration can be obtained. . The discharge air velocity is preferably 1 m / s
That is all.

As described above, in the apparatus of the present invention, the positive and negative ions generated by the AC corona discharge are transported by the film-shaped curtain airflow. It is possible to efficiently remove electricity from articles.

That is, when a cylindrical nozzle is used as in the latter case, since the discharged airflow spreads radially from the nozzle tip, the spatial distribution of the airflow velocity becomes uneven, and the ion concentration reaching the charged article also becomes uneven. Will occur. On the other hand, when ions are carried by a film-like curtain airflow as in the present invention, air ions having a uniform concentration can be sprayed in a layered manner on the charged article, and the ion wind can be uniformly spread over a wide range. Can be sprayed. In order to form a curtain airflow by the slit, it is preferable that the thickness (slit width) of the curtain airflow at the time of discharge be 10 mm or less and the blowing air velocity be 1 m / s or more.

In order to advantageously exert the function and effect of the use of such a slit type nozzle, the discharge electrodes 1 are preferably arranged at equal intervals in the center of the slit, and the counter electrode is shown in FIG. A ring-shaped member, a parallel bar-shaped member as shown in FIG. 7, or a grid-shaped member as shown in FIGS. The position of the discharge extreme 12 with respect to the counter electrode 2 may be either upstream or downstream.

When the present invention is applied to an application in which dust generated by deterioration of the metallic discharge electrode due to corona discharge does not significantly affect the product yield, an insulating material such as tungsten or titanium may be used as the discharge electrode. Can be used. In this case, a corona discharge can be generated without a counter electrode. However, if a counter electrode is used, corona discharge can be generated at a lower voltage.

An experimental example of the apparatus of the present invention will be described below.

FIG. 9 shows the outline of an experiment on the static elimination performance of a glass substrate using the apparatus of the present invention. The slit width of the apparatus used was 4 mm, and the discharge end 12 slightly protruded from the slit opening 3 was used. The discharge electrodes 1 are covered with quartz glass, and seven electrodes are attached at a pitch of 73 mm.
A 73 mm grid conductor was used.

An AC voltage of 11.5 kV was applied to the discharge electrode, and a DC voltage of -30 to -500 V was applied to the counter electrode. The gas is HEPA
Using the clean air that passed through the filter, the blowing velocity of the curtain airflow was 4.5 m / s.

As a charged object to be processed, 300 × 400 × 1.
1mm Corning large alkali-free glass (Fusion
7059), an insulator having a height of 10 mm was interposed between the conductor and a grounded conductor, and charged to about +1 to 2 kV in a state of being floated in the air. The apparatus of the present invention was operated, irradiation was performed for 5 seconds, and the static elimination efficiency was examined. At that time, the irradiation angle θ of the curtain airflow to the glass plate was 60 °, the airflow irradiation distance was L = 140 mm, and the measurement points were numbered as shown in FIG.

Table 1 shows the measurement results. Table 1 shows the surface potential (A) before static elimination and the surface potential after static elimination (5) for each of the cases where the glass substrate was charged positively and negatively.
(Irradiation for 2 seconds), the measured value of the surface potential (B), the charge removal amount (BA) and the charge removal potential ratio (discharge rate = (BA) / A) actually removed. In FIG. 10, the results in Table 1 are plotted, with the horizontal axis representing the point number of the measurement point and the vertical axis representing the charge removal potential ratio.

[0042]

[Table 1]

From the results shown in Table 1 and FIG. 10, according to the apparatus of the present invention, the surface potential of the entire glass substrate was uniformly reduced by 10 seconds in 5 seconds.
It can be seen that the result was less than the 1st place. Therefore, it is very effective for static elimination of a large liquid crystal substrate.

[0044]

As described above, according to the device of the present invention, the surface potential is uneven, as in a large liquid crystal substrate.
In addition, the static elimination of the charged article having a large surface area can be uniformly and reliably performed. Therefore, high quality products such as large liquid crystal substrates can be manufactured with high yield.

[Brief description of the drawings]

FIG. 1 is a schematic overall view showing an embodiment of the device of the present invention.

FIG. 2 is a cross-sectional view of the device of FIG. 1 taken along line II-II.

FIG. 3 is a bottom view of the device of FIG. 1;

FIG. 4 is a sectional view similar to FIG. 2 showing an example of mounting a discharge electrode.

FIG. 5 is a sectional view similar to FIG. 2, showing another example of mounting the discharge electrode.

FIG. 6 is a perspective view of the device of the present invention showing an example of mounting a counter electrode.

FIG. 7 is a perspective view of the device of the present invention showing another example of mounting the counter electrode.

FIG. 8 is a perspective view of the device of the present invention showing still another example of mounting the counter electrode.

FIG. 9 is a schematic diagram of a static elimination test of an alkali-free glass plate by the apparatus of the present invention.

FIG. 10 is a diagram in which the experimental results of FIG. 9 are plotted.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 discharge electrode 2 counter electrode 3 slit-shaped opening 4 air supply chamber 5 connection port to air supply source 6 perforated plate 7 upper space 8 lower space 9 discharge electrode lead wire 12 discharge electrode discharge end 14 quartz glass tube 15 holder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-11591 (JP, A) JP-A-4-106977 (JP, A) JP-A-3-230500 (JP, A) 502466 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05F 3/00-3/06 H01T 19/00-23/00

Claims (3)

(57) [Claims] An axial direction is provided on a lower surface of a cylindrical air supply chamber.
A slit opening 3 is provided along the
The inside of the bar 4 is divided into an upper space 7 and a lower space 8 by a perforated plate 6.
Supply for introducing air from the air supply source into the upper space 7
A port 5 is provided and the supply port 5 leads to the upper space 7.
The incoming airflow is rectified by the perforated plate 6 and flows into the lower space 8.
After being cut, a car of uniform speed in the width direction from the slit-shaped opening 3
Configured to discharge as ten stream, a plurality of discharge electrodes 1 for corona discharge along the longitudinal direction of the slit in the slit-shaped opening 3 is continuously arranged at predetermined intervals, ground or DC power
The counter electrode 2 connected to the source is located outside the slit-shaped opening 3.
A neutralizing device for charged articles attached to 2. An axial direction on the lower surface of the cylindrical air supply chamber 4.
A slit opening 3 is provided along the
The inside of the bar 4 is divided into an upper space 7 and a lower space 8 by a perforated plate 6.
Supply for introducing air from the air supply source into the upper space 7
A port 5 is provided and the supply port 5 leads to the upper space 7.
The incoming airflow is rectified by the perforated plate 6 and flows into the lower space 8.
After being cut, a car of uniform speed in the width direction from the slit-shaped opening 3
It is configured to discharge as an air stream, and
A plurality of the covered discharge electrodes 1 for corona discharge are inserted into the slit.
At predetermined intervals along the longitudinal direction of the slit.
Linear counter electrode connected to a ground or DC power supply
2 is applied to each discharge electrode 1 in a ring, grid or flat shape.
A neutralizing device for charged articles that is mounted in a row bar shape . 3. The counter electrode 2 is made of gold coated with a resin material.
Neutralizer charging article according to claim 1 or 2 consisting of the genus line.