JPH0888074A - Discharge electrode for ion generating device - Google Patents

Abstract

PURPOSE: To enhance the carrying efficiency of ions by letting a gas blow-out port be opened at the tip end face of an ion generating section. CONSTITUTION: The main body 11 of a discharge electrode is made out of a metal, or polycrystal silicone and the like, and is formed into a round bar shape. A convergent tapered section 12 is formed at the tip end section of the main body 11, when positive or negative high voltage is applied to the main body 11, a great amount of ions is generated out of the vicinity of the tip end section of the tapered section 12 as compared with the other sections. A curved surface section 4 in a circular arc shape is formed at the intersecting section of the tip end face of an ion generating section 13 with its outer circumference. A blow out port is formed inside the main body 11 while being penetrated through the inside from its rear end face to its tip end face. A gas feed source is connected to the rear end section of the blow out port 15, and fed gas is so designed as to be blown out forward out of an open section at the tip end section of the ion generating section 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge electrode used in an ion generator.

[0002]

2. Description of the Related Art Generally, when an object is charged, particles in the air such as dust are electrostatically adsorbed. So L
For semiconductor products such as SI, which do not like the particles to adhere to the surface of the product, an ion generator is used to remove the static electricity of the product.

FIGS. 13 to 15 show a conventional ion generator. The ion generator shown in FIG. 13 has a discharge electrode b on the outer surface of the apparatus main body a and a discharge electrode b around the discharge electrode b. The gas outlet c is opened, and when a positive or negative high voltage is applied to the discharge electrode b via the high voltage line d, negative or positive ions are generated near the tip of the discharge electrode b. This ion is carried forward by the air blown out from the blow-out hole c and brought into contact with a product (not shown), whereby the product is electrically neutralized.

The ion generator shown in FIG. 14 is provided with a fan f for blowing air inside a tube e and a discharge electrode b in front of the fan f. The ion generator shown in FIG. A discharge electrode b is provided in the air passage g, and both are designed to electrically neutralize the product in the same manner as the ion generator shown in FIG.

[0005]

In each of the above-described conventional ion generators, the air is blown around the discharge electrode b, but the air that carries ions among the blown air is in the vicinity of the discharge electrode b. Only a part of the air passing therethrough, and the air flowing away from the discharge electrode b hardly carries the ions, resulting in poor ion carrying efficiency. Therefore, in order to convey a large amount of generated ions to the product,
It was necessary to blow out a large amount of air at a relatively high speed. However, when blowing out a large amount of air at high speed, there is a problem that the product will be blown off if the product to be discharged is small, and dust and particles on the workbench on which the product is placed are scattered by the wind, There was a problem that this adheres to the product again.

[0006]

The present invention has been made to solve the above problems. In the invention according to claim 1, a gas blowout hole is opened in the tip surface of the ion generating portion. Is characterized by. In this case, it is desirable that the intersection of the tip end surface of the ion generating portion and the inner peripheral surface of the opening of the blowout hole is formed as a ridge line. Further, it is desirable to form a convex curved surface at the intersection of the outer peripheral portion of the tip surface of the ion generating portion. Incidentally, only one blowout hole may be formed,
A large number may be formed. Further, the shape of the opening of the blowout hole is arbitrary, and it can be formed in a circular shape or an elongated slit shape in accordance with the shape of the product.

[0007]

In the invention according to claim 1, since the entire inner circumference of the blowout hole is in contact with the main body, most of the blown gas contributes to the transport of ions. Therefore, the transportation efficiency is improved. Therefore, it suffices to convey ions only at a low speed and blow a small amount of gas. In the invention according to claim 2, since the intersection of the tip surface of the ion generating portion and the inner peripheral surface of the opening of the blowout hole forms a ridge, a large amount of ions are generated near the opening. Therefore, a large amount of ions can be transported at a lower speed and by blowing out a small amount of gas. In the invention according to claim 3, since the intersection of the tip end surface and the outer peripheral surface of the ion generating portion is a curved surface portion that is convex outward, the amount of ions generated in the outer peripheral portion of the ion generating portion is reduced, As a result, a large amount of ions are generated near the opening of the blowout hole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.
2 will be described. 1A to 1C show a first embodiment of the present invention, in which the discharge electrode 1 is a main body 11
have. The main body 11 is made of stainless steel, a metal such as tungsten or titanium, or polycrystalline silicon, and has a round bar shape. This body 1
A tapered taper portion 12 is formed at the tip portion of No. 1, and when a positive or negative high voltage is applied to the main body 11, a large amount of ions are generated from the vicinity of the tip portion of the taper portion 12 compared to other portions. appear. That is, the tip of the tapered portion 12 is the ion generating portion 13. A curved surface portion 14 having an arc shape with a substantially quarter section is formed over the entire circumference at the intersection of the tip surface and the outer peripheral surface of the ion generating portion 13.

A blowout hole 15 penetrating from the rear end face to the front end face is formed inside the main body 11. A gas supply source (not shown) for supplying a gas such as air or argon gas is connected to the rear end portion of the blowout hole 15, and the supplied gas is forward from the opening of the tip surface of the ion generating portion 13. It is designed to blow out. Further, the inner peripheral surface of the blowout hole 15 and the tip end surface of the ion generating portion 13 intersect at a right angle, and the intersecting portion is a sharp ridge line without roundness.

When the charged product is discharged by using the discharge electrode 1 having the above structure, the discharge electrode 1 is fitted and fixed to the insulating holding cylinder A as shown in FIG. Connect to AC or DC power source C via B. Further, the outlet 15 is connected to a gas cylinder E through a pipe D having an insulating property. Then, with the opening of the outlet 15 facing the product (not shown), a high voltage is applied to the discharge electrode 1 and gas is blown out from the outlet 15.

When a high voltage is applied to the discharge electrode 1, a large amount of ions are generated near the tip surface of the ion generator 13. In particular, in this embodiment, in consideration of the fact that a large amount of ions are generated from the vicinity of the sharp portion of the discharge electrode, the curved surface portion 14 is formed on the outer peripheral portion of the tip surface, while the ion generating portion 13 is formed.
Since a sharp ridge line is formed at the intersection of the tip surface of the outlet and the inner peripheral surface of the outlet 15, a large amount of ions are generated near the opening of the outlet 15. The ions are carried to the product by the gas blown from the blowout port 15 and come into contact with the charged product to electrically neutralize the product.

Here, the gas blown from the blowout port 15 is
It is in contact with the main body 11 around the entire circumference of the blowout port 15, and almost all of the blown gas is used for the transport of ions. Therefore, the efficiency of ion transport is improved, and a large amount of ions can be transported to the product at a relatively low speed and only by blowing out a small amount of gas. Further, since it is sufficient to blow out a small amount of gas at a low speed, it is possible to prevent the product from being blown off. Moreover, since dust or fine particles accumulated on the workbench on which the product is placed is not blown up by the wind, it is possible to prevent dust or the like from reattaching to the product.

Since ions are also generated in the gas blown out from the air outlet 15, it is desirable to use a gas that can generate as much ions as possible. From this point of view, it is desirable to use an inert gas such as argon gas rather than air.

Next, the result of an experiment conducted for confirming the static elimination performance of the discharge electrode 1 will be described. In this experiment, the tip of a rod having an outer diameter of 1.0 mm was ground into a needle shape, and a blowout hole 15 having an inner diameter of 0.3 mm was formed in this to form the discharge electrode 1. Then, as shown in FIG. 10, the discharge electrode 1 is arranged above the central portion of the product F to be neutralized by a distance L (L = 500 mm) so that the blown gas may hit the product F at a right angle. did. Product F
As the stainless steel plate, an outer diameter of 200 mm and a thickness of 1 mm was used. Also, experiments were carried out using dry air and dry argon gas as the gas to be sprayed.

In this experiment, the product F was charged by applying a voltage of 2000 V to the product F by the DC power supply G, and then an AC voltage of 10 KV was applied to the discharge electrode 1.
The time required for the voltage to reach 100 V was measured. Also,
The flow rate of the gas blown out from the blowout hole 15 is 0 to 1.0 l
/ Min. The experimental results are shown in FIG. As is clear from this figure, when the gas flow rate is 0 l / min, that is, when the gas is not blown, the time required for the voltage of the product F to decrease from 2000 V to 100 V is 100 seconds. On the other hand, 1.0 l / mi
It was 20 seconds when n dry air was blown and 10 seconds when the same amount of dry argon gas was blown, and the static elimination time could be shortened to 1/5 and 1/10, respectively.

Next, another embodiment of the discharge electrode according to the present invention will be described. In the discharge electrode 2 shown in FIG. 2, the tip surface of the ion generating portion 13 is a tapered surface 13a, and the blowout hole 15 is formed.
It intersects the inner surface of the car at an acute angle. in this way,
When the intersection between the inner peripheral surface of the blowout hole 15 and the tapered surface 13a is formed at an acute angle, a larger amount of ions are generated near the intersection. Therefore, the efficiency of transporting ions by the gas blown out from the blowout holes 15 can be further improved.

The discharge electrode 3 shown in FIG. 3 is formed by forming the entire main body 11 into a cylindrical shape having a constant outer diameter without forming the tapered portion 12 at the tip of the main body 11.

The discharge electrode 4 shown in FIG. 4 is a modification of the discharge electrode 1 shown in FIG. 3. In the discharge electrode 1 shown in FIG. 3, the tip end surface is made orthogonal to the longitudinal direction of the main body 11. The front end surface is obliquely crossed with the longitudinal direction.

The discharge electrode 5 shown in FIG. 5 comprises a main body 11 composed of a base portion 11a and three branch portions 11b branched from the tip of the base portion 11a.
The tip of b is the ion generating part 13. Of course, blow-out holes 15 are opened at the tip end surface of each ion generating portion 13, and each blow-out hole 15 is integrated in the base portion 11a and is opened at the rear end surface of the base portion 1a. This discharge electrode 5 is convenient to use when the product is long or when the products are arranged in a line.

The discharge electrode 6 shown in FIG. 6 is formed by forming the main body 11 into a cylindrical shape having a bottom at the tip, and forming a number of blowout holes 15 at the bottom. Further, in order to reduce the amount of ions generated near the tip outer peripheral portion of the discharge electrode 6 as much as possible, a chamfer 17 is formed on the tip outer peripheral portion. Of course, a curved surface portion may be formed instead of the chamfer 17.
The discharge electrode 6 is suitable for use when the area of the product to be discharged is large.

The discharge electrode 7 shown in FIG. 7 is a body 11 having a bottomed cylindrical shape with an elongated blowout hole 15 formed in it, and is suitable for use when the product is elongated.

A discharge electrode 8 shown in FIG. 8 is formed by forming a main body 11 into a rectangular parallelepiped shape having a rectangular cross section. The main body 11 has an elongated end surface with its longitudinal direction oriented in the same direction as the longitudinal direction of the distal end surface. The blowout hole 15 is formed. Also, the main body 1
The base end portion of No. 1 is covered with an insulator 18.

FIG. 12 shows an example in which the discharge electrode 1 shown in FIG. 1 is used in a vacuum deposition apparatus or an ion implantation apparatus used in a semiconductor manufacturing process. The blowout hole 1 while penetrating the container H
5 is arranged with the opening of 5 facing the product I, and the insulating material J
It is airtightly fixed to the decompression container H via. The discharge electrode 1 is supported by a support member K made of an insulating material and connected to a high voltage power source L. On the other hand, the blowout hole 15 is open to the outside air via the valve M.

In the above-mentioned apparatus, when the product I is destaticized, the decompression container H is evacuated to perform vacuum deposition, for example, and then a voltage is applied to the discharge electrode 1 and the valve M is opened. Then, the outside air is vacuumed and blown out from the blowout hole 15. Ions are generated by applying a high voltage to the blown air. This is conveyed by the blown air and comes into contact with the product I to electrically neutralize the product I. According to such an apparatus, a pump or the like for supplying air is unnecessary, so that the entire apparatus can be manufactured inexpensively.

[0025]

As described above, according to the first aspect of the invention, it is possible to improve the ion transport efficiency, and therefore, it is sufficient to blow out a small amount of gas at a low speed from the blowout hole to remove the charge. It is possible to prevent a situation in which a desired product is blown off, and it is possible to prevent dust or the like on the workbench on which the product is placed from flying up and reattaching to the product. Further, according to the invention of claim 2 or claim 3, since a large amount of ions can be generated from the vicinity of the opening of the blowout hole, the efficiency of ion transport can be further improved.

[Brief description of drawings]

FIG. 1 shows a discharge electrode 1 according to the present invention.
1A is a sectional view thereof, FIG. 1B is an enlarged view taken along arrow X in FIG. 1A, and FIG. 1C is an enlarged sectional view of a tip portion of a discharge electrode 1.

FIG. 2 is a sectional view of the discharge electrode 2 according to the present invention, similar to FIG. 1 (C).

FIG. 3 is a partially omitted perspective view of a discharge electrode 3 according to the present invention.

FIG. 4 is a partially omitted perspective view of a discharge electrode 4 according to the present invention.

FIG. 5 is a partially omitted perspective view of a discharge electrode 5 according to the present invention.

FIG. 6 is a partially omitted perspective view of a discharge electrode 6 according to the present invention.

FIG. 7 is a partially omitted perspective view of a discharge electrode 7 according to the present invention.

FIG. 8 is a perspective view of a discharge electrode 8 according to the present invention.

9 is a perspective view showing a discharge device using the discharge electrode 1 shown in FIG.

10 is a diagram showing a schematic configuration of an experimental device when a static elimination experiment by the discharge device shown in FIG. 10 was performed.

11 is a graph showing the static elimination time by the experimental device shown in FIG. 11, the solid line shows the static elimination time by dry air,
The broken line shows the static elimination time with argon gas.

12 is a cross-sectional view showing a schematic configuration of an example in which the discharge electrode 1 shown in FIG. 1 is used in a vacuum vapor deposition device or an ion implantation device.

FIG. 13 is a partially omitted sectional view showing an example of a conventional static eliminator.

FIG. 14 is a partially omitted cross-sectional view showing another example of the conventional static eliminator.

FIG. 15 is a sectional view showing a schematic configuration of still another example of the conventional static eliminator.

[Explanation of symbols]

 1 Discharge Electrode 2 Discharge Electrode 3 Discharge Electrode 4 Discharge Electrode 5 Discharge Electrode 6 Discharge Electrode 7 Discharge Electrode 8 Discharge Electrode 11 Main Body 13 Ion Generating Section 14 Curved Section 15 Blowout Hole

Claims (3)

[Claims] 1. A discharge electrode for an ion generating device, characterized in that a gas blowout hole is opened in the tip surface of the ion generating portion. 2. The discharge electrode for an ion generating device according to claim 1, wherein the intersection of the tip end surface of the ion generating portion and the inner peripheral surface of the opening of the blowout hole forms a ridge. 3. The discharge electrode for an ion generating device according to claim 1, wherein a curved surface portion which is convex outward is formed at an intersection of the tip end surface of the ion generating portion and the outer peripheral surface. .