Patent Grant
11765810
This application is the national phase entry under 35 U.S.C. § 371 of international patent application No. PCT/JP2020/019358 filed May 14, 2020 and claims the benefit of Japanese patent application No. 2019-092937, filed May 16, 2019, the disclosures of which are incorporated herein by reference in their entirety.
The present invention relates to a soft X-ray static electricity removal apparatus. More particularly, it relates to a soft X-ray static electricity removal apparatus that discharges a large amount of ions.
It has been conventionally known that in a step of processing or handling a semiconductor substrate, a liquid crystal substrate, or an organic EL substrate in a semiconductor, liquid crystal, or organic EL manufacturing process, static electricity is charged on a surface of the substrate and the static electricity causes a trouble that a circuit of the semiconductor substrate, liquid crystal substrate, or organic EL substrate breaks. In addition, electric charging on each substrate also causes a trouble that dust adheres to its surface.
As measures against such troubles, a static electricity removal apparatus that generates ions for preventing electric charging and removing static electricity on a substrate surface is installed in semiconductor, liquid crystal, and organic EL manufacturing apparatuses. As the static electricity removal apparatus, a corona discharge static electricity removal apparatus that ionizes air by high voltage and a soft X-ray static electricity removal apparatus that irradiates air with a soft X ray to ionize air are provided.
In the corona discharge static electricity removal apparatus, particles from an electrode are generated at the time of discharge; while in the soft X-ray static electricity removal apparatus, particles do not occur but leakage of soft X-rays affects human bodies. Thus, both have their respective demerits.
Under the circumstances, a soft X-ray static electricity removal apparatus that takes out only ionized air and does not allow leakage of a soft X-ray to the outside has been developed; however, its structure is complicated. Therefore, one of the inventors has previously proposed a soft X-ray shielding sheet that can prevent leakage of soft X rays from a discharge port with a simple structure by allowing soft X-rays that enter from a supply port to hit a passage at least three or more times before reaching the discharge port so that their travel in a straight line is prevented to make the soft X-rays attenuated or disappear (see Patent Literature 1).
Patent Literature 1
However, as semiconductors and the like are increasingly miniaturized, a demand for further increasing the amount of ionized air discharged and in addition, a demand for adjusting the amount of positive ions/negative ions have been arising. Therefore, it is an object of the present invention to provide a soft X-ray static electricity removal apparatus that achieves a further increase in the amount of ionized air discharged with a simple structure. Furthermore, it is an object of the present invention to provide a soft X-ray static electricity removal apparatus that can adjust the amount of positive ions/negative ions discharged.
To solve the above problem, a soft X-ray static electricity removal apparatus 1 according to a first aspect of the present invention includes, as illustrated in
In this configuration, air can be ionized by soft X-rays, the soft X-rays can be shielded while allowing passage of the ionized air with the soft X-ray shielding sheet, and further the soft X-ray shielding sheet is insulated from the container. Thus, the ionized air is not trapped by the soft X-ray shielding sheet and the amount of ionized air discharged increases.
In a soft X-ray static electricity removal apparatus 1 according to a second aspect of the present invention, as illustrated in
In a soft X-ray static electricity removal apparatus 1 according to a third aspect of the present invention, as illustrated in
In a soft X-ray static electricity removal apparatus 1 according to a fourth aspect of the present invention, as illustrated in
A soft X-ray static electricity removal apparatus 1 according to a fifth aspect of the present invention further includes, as illustrated in
A soft X-ray static electricity removal apparatus 1 according to a sixth aspect of the present invention further includes, as illustrated in
According to the soft X-ray static electricity removal apparatus of the present invention, air can be ionized by soft X-rays, the soft X-rays can be shielded while allowing passage of the ionized air with the soft X-ray shielding sheet, and further the soft X-ray shielding sheet is insulated from the container. Thus, the amount of ionized air discharged can be increased. In addition, by applying a potential difference to the container and the soft X-ray shielding sheet, the amount of positive ions/negative ions discharged can be adjusted.
This application is based on Japanese Patent Application No. 2019-092937 filed on May 16, 2019 in Japan, the contents of which form part of the present application.
The present invention will also be more fully understood from the following detailed description. However, the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given for illustrative purposes only. From this detailed description, various changes and modifications will be apparent to those skilled in the art.
The applicant does not intend to dedicate any described embodiments to the public, and to the extent any disclosed modifications or alterations may not literally fall within the scope of the claims, they are considered to be part hereof under the doctrine of equivalents.
The use of the terms “a” and “an” and “the” and similar referents in the context herein or the context of the claims are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of any examples, or exemplary language (e. g., “such as”) provided herein, is intended merely to better illustrate the present invention and does not pose a limitation on the scope of the invention unless otherwise claimed.
Hereinafter, an embodiment of the present invention will be described with reference to drawings. It should be noted that in the drawings, the same or corresponding devices are denoted by the same reference numerals, thereby omitting redundant descriptions thereof. First, with reference to
The soft X-ray static electricity removal apparatus 1 includes a container 10 that provides a space in which air is ionized and through which ionized air 100, which has been ionized, flows. The container 10 has an air inlet 14 that takes air 102 into the container 10. The air inlet 14 may include a fan to forcibly take the air 102 outside the container 10 into the container 10. In the container 10, a soft X-ray generation device 90 is arranged near a position where the air inlet 14 is provided. Soft X-rays 92 are generated from the soft X-ray generation device 90 and air is irradiated therewith within the container 10; thereby the air is ionized. The soft X-ray generation device 90 may be a known soft X-ray device and thus, detailed description thereof is omitted. On the container 10, an outlet 12 for the ionized air 100 is formed at a position away from a position where the air inlet 14 is provided. By providing the soft X-ray generation device 90 near the air inlet 14 and providing the outlet 12 at a position away from the air inlet 14, air is caused to flow from the air inlet 14 to the outlet 12, the air can be ionized by the soft X-rays 92 from the soft X-ray generation device 90, and the ionized air 100 is discharged from the outlet in a short period of time. Thus, this arrangement is preferable; but other arrangements are acceptable. In general, the container 10 is formed by stainless steel or other metal.
At the outlet 12, a soft X-ray shielding sheet 20 is arranged. That is, the ionized air 100 is discharged from the container 10 by passing through the soft X-ray shielding sheet 20.
Here, with reference to
In the present example, two supply ports 32 in the first outer sheet 30 are formed so as to provide spacing between them on the first outer sheet 30. The ionized air passage 38 in the interlayer sheet 34 includes the ionized air inlet openings 36 which are respectively formed at positions where communication with the supply ports 32 in the first outer sheet 30 is performed; and is formed so as to communicate with each of the ionized air inlet openings 36. The discharge port 42 in the second outer sheet 40 is formed at a position where communication with the ionized air passage 38 is performed in the interlayer sheet 34.
By stacking and adhering the first outer sheet 30, the interlayer sheet 34, and the second outer sheet 40, which are formed as described above, the supply ports 32 in the first outer sheet 30 and the ionized air inlet openings 36 in the interlayer sheet 34 are made to communicate with each other, respectively and furthermore, at the center of the ionized air passage 38 in the interlayer sheet 34, the ionized air passage 38 and the discharge port 42 in the second outer sheet 40 communicate with each other; thereby forming an ionized air transmission portion 44. In the soft X-ray shielding sheet 20, one ionized air transmission portion 44 may be formed; however, a plurality of ionized air transmission portions 44 may be formed.
In the ionized air passage 38, bent portions 39 that bend at 90 degrees on a plane are provided so that the number of times the soft X-rays 92 hit an inner surface 41 of the second outer sheet 40 and an inner surface 31 of the first outer sheet 30 while entering from the supply ports 32 and reaching the discharge port 42 increases and the soft X-rays 92 are attenuated or disappear.
In addition, in order that a fluid resistance of the ionized air 100, which has been ionized, is controlled so as to allow the ionized air to reach the discharge port 42 in a short period of time and so as to prevent recombination of positive ions and negative ions, each of the bent portions 39 of the ionized air passage 38 is formed to have a curved face 37 that is to reduce the fluid resistance of the ionized air. That is, the ionized air passage 38 has at least one or more bent portions 39 that bend at 90 degrees on a plane and thereby allows the soft X-rays 92 to disappear due to its hit on an inner surface, that is, the passage. It should be noted that the shape of the ionized air passage 38 may be other shapes. The shape is preferably such that the fluid resistance of the ionized air 100 is controlled while the number of times the soft X-rays 92 hit the passage is increased.
The operation of the soft X-ray shielding sheet 20 which is used in the soft X-ray static electricity removal apparatus 1 of the present invention according to the above configuration will be described with reference to
The soft X-rays 92 are incident from each of the supply ports 32 and go straight, pass the ionized air passage 38 through the ionized air inlet openings 36, and reach the discharge port 42; during which as illustrated in
The ionized air 100 introduced from the supply ports 32 passes through the ionized air passage 38 and reaches the discharge port 42. Since the bent portions 39 of the ionized air passage 38, which are provided from the viewpoint of preventing leakage of the soft X-rays 92, are formed to have the curved face 37, the fluid resistance is reduced, allowing the ionized air 100 to reach the discharge port 42 in a short period of time. In particular, it is preferable that the ionized air 100 should pass through the soft X-ray shielding sheet 20 in a short period of time so as to prevent recombination of positive ions and negative ions; and thus, the path of the ionized air transmission portion 44 is shortened. Therefore, a large amount of ions are discharged to a downstream side of the discharge port 42.
In the case of the soft X-ray shielding sheet 20 illustrated in
However, as illustrated in
Then, as illustrated in
The container 10 and the soft X-ray shielding sheet 20 are insulated from each other by the insulating layer 50 and thereby when ions are trapped in the soft X-ray shielding sheet 20 in an initial stage of operation, the soft X-ray shielding sheet 20 gets the potential of trapped ions (positive or negative) and thereafter, ions of the same potential are not trapped and are transmitted through the soft X-ray shielding sheet 20. Therefore, the ionized air 100 that is discharged through the soft X-ray shielding sheet 20 increases.
Furthermore, since insulation is made with the insulating layer 50, a potential difference can be applied to the container 10 and the soft X-ray shielding sheet 20. As illustrated in
As described so far, according to the soft X-ray static electricity removal apparatus 1 of the present invention, the soft X-ray shielding sheet 20 is insulated and thereby the amount of ionized air 100 discharged can be increased. In addition, a potential difference is applied to the container 10 and the soft X-ray shielding sheet 20 and thereby, the amount of positive/negative ions discharged can be adjusted.
Here, an experiment for confirming the effects of the insulating layer of the soft X-ray static electricity removal apparatus is described. Here, the effects of the insulating layer were confirmed by measuring the time taken to remove static electricity from a charge plate by using a soft X-ray static electricity removal apparatus with an insulating layer and a soft X-rays static electricity removal apparatus without an insulating layer. The soft X-ray static electricity removal apparatus used in the experiment is C-IGB-CA-100434 manufactured by Kondoh Industries, Ltd. and its outer shape is illustrated in
The results shown in Table 1 are averages of three actual measurements. Items indicated by “***” in Table 1 indicate results that static electricity was not removed (not lowered to 100 V) after 200 seconds had passed.
As is obvious from the results in Table 1, it was found that by providing an insulating layer, the static electricity removal time is shortened except with some exceptions. Especially, in the case where the static electricity removal time was long without an insulating layer at the distance of 150 mm or 200 mm, the static electricity removal time was significantly shortened. This is considered to be a result of discharging a large amount of ionized air and thereby removing static electricity from the charge plate.
Next, described will be an experiment in which it was confirmed that the amount of positive/negative ions discharged can be adjusted by applying a potential difference to the container 10 and the soft X-ray shielding sheet 20 (see
The results shown in Table 2 are averages of three actual measurements. A difference in the results in the voltage applied of ±0 V from those in Table 1 is estimated to be because measurement dates were different and the static electricity removal time, which is greatly influenced by atmospheric conditions (humidity, temperature, and the like), was changed due to the influence of a different atmosphere.
When a potential difference of +10 V was applied to the soft X-ray shielding sheet (conversely, −10 V to the container), the time for removing a positive voltage became short in comparison with a case where the potential difference was not applied, that is, the discharge of negative ions increased; and the time for removing a negative voltage became long, that is, the discharge of positive ions decreased. In addition, when a potential difference of −10 V was applied to the soft X-ray shielding sheet (conversely, +10 V to the container), the time for removing a positive voltage became long in comparison with a case where the potential difference was not applied, that is, the discharge of negative ions decreased; and the time for removing a negative voltage became short, that is, the discharge of positive ions increased. In short, when a positive voltage was applied to the soft X-ray shielding sheet and a negative voltage was applied to the container, dispersion of negative ions on an inner wall of the container decreased and negative ions in the container increased. As a result, it is estimated that the amount of negative ions discharged increased and the time for removing a positive voltage became short. Conversely, it is estimated that when a negative voltage and a positive voltage were applied to the soft X-ray shielding sheet and the container, respectively, positive ions in the container increased and thereby the amount of positive ions discharged increased and the time for removing a negative voltage became short.
As is also obvious from Table 2, by applying a potential difference to the container and the soft X-ray shielding sheet, the amount of positive/negative ions discharged can be adjusted.
The main reference numerals used in the description and drawings are listed below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-092937 | May 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/019358 | 5/14/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/230873 | 11/19/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5055963 | Partridge | Oct 1991 | A |
| 20060018808 | Taylor | Jan 2006 | A1 |
| 20220256680 | Kisakibaru | Aug 2022 | A1 |
| Number | Date | Country |
|---|---|---|
| 2157611 | Jan 2001 | CA |
| 2879015 | Mar 2007 | CN |
| 102005000983 | Jul 2006 | DE |
| 102021117682 | Sep 2022 | DE |
| 7-6860 | Jan 1995 | JP |
| 2001-257096 | Sep 2001 | JP |
| 2007-48539 | Feb 2007 | JP |
| WO-03049509 | Jun 2003 | WO |
| WO 2008023727 | Feb 2008 | WO |
| Entry |
|---|
| Japanese Patent Office, International Search Report; International Application No. PCT/JP2020/019358; 2 pages; dated Jul. 21, 2020. |
| European Patent Office, Extended European Search Report issued in EP Application No. 20804912.2, dated May 12, 2023, 58 pp. |
| Number | Date | Country | |
|---|---|---|---|
| 20220256680 A1 | Aug 2022 | US |
