JP2018147698A - Electrode unit, plasma processing device, and electrode cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode unit etc. which can inhibit temperature rise of an electrode covered by a tubular dielectric body.SOLUTION: An electrode unit 3 is used to generate plasma in a container 2 by glow discharge and includes: an elongated electrode 31; and a tubular dielectric body 32 covering the electrode 31. The electrode 31 has a space 31a extending along a longitudinal direction therein, and the space 31a can communicate with the outside of the container 2.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an electrode unit that generates plasma by glow discharge, a plasma processing apparatus including the electrode unit, and a method for cooling the electrode unit.

  A plasma processing apparatus using glow discharge plasma has been proposed for the purpose of surface modification of substances such as powder (for example, Patent Document 1). The apparatus described in Patent Document 1 includes a container having a center electrode, a cylindrical peripheral electrode disposed through the center electrode and a predetermined gap, and a substantially total length of the gap is a plurality of partitions. A plurality of chambers formed by partitioning, a dielectric provided on at least one of the central electrode surface or the peripheral electrode surface, and provided on one end side of the container so that fluid can be injected into the chamber. AC fluid or pulse voltage between the center electrode and the peripheral electrode, the fluid injecting means configured, the fluid discharging means provided on the other end side of the container and configured to be able to discharge the fluid from the room And rotating means for rotating the container around the center electrode as a center of rotation.

Japanese Patent No. 5080701

In the above plasma processing apparatus, when a rod-like electrode is used as the center electrode and the rod-like electrode is covered with a dielectric such as a glass tube, the temperature of the center electrode rises during glow discharge.
Note that the temperature increase of the center electrode may have adverse effects such as surface degradation depending on the substance to be plasma-treated.
An object of this invention is to provide the electrode unit etc. which can suppress the temperature rise of the electrode with which the tubular dielectric material is coat | covered.

An electrode unit according to the present invention is an electrode unit for generating plasma by glow discharge in a container, and includes an elongate electrode and a tubular dielectric covering the electrode, and the electrode is arranged in the longitudinal direction. There is a space extending along the inside, and the space can communicate with the outside of the container.
The plasma processing apparatus according to the present invention is a plasma processing apparatus for processing a substance by plasma generated by glow discharge between a pair of electrode units, wherein one of the pair of electrode units is the electrode unit.
The electrode cooling method according to the present invention is an elongate electrode cooling method in which a plasma is generated by glow discharge in a vessel, which is covered with a tubular dielectric, and an internal space extending along the longitudinal direction of the electrode. Let the fluid flow.

  The electrode unit and the plasma processing apparatus according to the present invention can suppress an increase in the temperature of the electrode by causing a fluid to flow in the space in the electrode.

It is the schematic of the plasma processing apparatus which concerns on embodiment, (a) is a side view, (b) is a front view. It is a side view of the state removed from the support unit. It is front sectional drawing of the state removed from the support unit. It is a front view of the state which removed the container main body from the container which removed the connection subunit and the fluid supply unit. It is the side view which looked at the state of FIG. 4 from the one end side. It is the figure which looked at the BB cross section in FIG. 4 from the arrow direction. It is an expanded sectional view of an electrode part. It is front sectional drawing to which the edge | side of the gas injection unit and the fluid supply unit was expanded. It is front sectional drawing to which the fluid supply unit was expanded.

<Overview>
An electrode unit according to an aspect of an embodiment is an electrode unit for generating plasma by glow discharge in a container, and includes an elongated electrode and a tubular dielectric covering the electrode, A space extending along the longitudinal direction is provided inside, and the space can communicate with the outside of the container. Thereby, the electrode can be cooled.
In the electrode unit according to another aspect of the embodiment, there are a plurality of electrodes, and the space of two or more electrodes is connected to form a single communication path that communicates with the outside of the container. As a result, the means for flowing the fluid into the electrode space can be limited.
In the electrode unit according to another aspect of the embodiment, the end of the electrode located on one end side of the one communication path and the end of the electrode located on the other end side of the one communication path are Located outside the container. This facilitates a structure for allowing fluid to flow into the electrode space.
In the electrode unit according to another aspect of the embodiment, the number of the two or more is two, the end of the electrode is one end of the electrode, and the other end of the two electrodes is the container. The support body has a connection path that connects the spaces of the two electrodes in a communication state. This eliminates the need to separately provide a member for connecting the two electrodes in a communicating state.
In the electrode unit according to another aspect of the embodiment, the plurality of electrodes are arranged on a virtual circumference when viewed from the longitudinal direction, and the two electrodes are adjacent to each other in the circumferential direction. Thereby, the connection of the space inside two electrodes can be performed easily.
The plasma processing apparatus which concerns on 1 aspect of embodiment is a plasma processing apparatus which processes a substance with the plasma which generate | occur | produces by the glow discharge between a pair of electrode units, and one of the said pair of electrode units is an electrode unit as described above . Thereby, the electrode can be cooled.
An electrode cooling method according to an aspect of the embodiment is a method for cooling an elongated electrode that is covered with a tubular dielectric and generates plasma by glow discharge in a container, and extends along the longitudinal direction of the electrode. Fluid flows into the internal space. Thereby, an electrode can be cooled efficiently.

<Embodiment>
1. Plasma Processing Apparatus A plasma processing apparatus 1 according to one aspect of the embodiment will be described with reference to FIG.
The plasma processing apparatus 1 includes a container 2, an inner electrode unit 3 disposed inside the container 2, and an outer electrode unit 4 disposed outside the container 2.
The plasma processing apparatus 1 generates plasma for improving the surface of a substance disposed (supplied), for example, inside the container 2. Here, the plasma uses glow discharge generated between the inner electrode unit 3 and the outer electrode unit 4 by applying a high voltage to the inner electrode unit 3. The inner electrode unit 3 corresponds to an aspect of the electrode unit according to the present invention. Since the electrode of the outer electrode unit is a ground electrode, the outer electrode unit is an outer ground electrode unit, and the symbol “4” is used as it is.
The plasma processing apparatus 1 according to the present embodiment includes an electrical connection unit 5 that connects a high voltage power source for generating glow discharge and the inner electrode unit 3. Since the outer earth electrode unit 4 is also connected to the ground (earth), the electrical connection unit 5 includes a connection between the outer earth electrode unit 4 and the ground side.
The plasma processing apparatus 1 includes a gas injection unit 6 that injects an inert gas into the container 2. The plasma processing apparatus 1 includes a fluid supply unit 7 for supplying a fluid for cooling the electrode 31 of the inner electrode unit 3. The plasma processing apparatus 1 includes a support unit 8 that rotatably supports the container 2.
The container 2 is cylindrical, and the direction in which the central axis extends is simply the central axis direction, and the radial direction of the container 2 is simply the radial direction. Further, in the direction of the central axis of the container 2, the side where the gas injection unit 6 exists (the left side in FIG. 1B) is one end, and the side where the container 2 exists (the right side in FIG. 1B). Is the other end.

2. Each part structure (1) container It demonstrates using FIG. 3 mainly.
The container 2 is made of an insulating material. Here, it is made of a glass material. The glass material is a dielectric and assists in generating a barrier discharge. The container 2 has a cylindrical shape with both ends closed. Here, since the container 2 is rotatably supported by the support unit 8, the outer periphery has a circular shape. The container 2 has a cylindrical shape with substantially constant inner and outer diameters, and both ends thereof are closed. The container 2 includes, for example, a container body 21 having a bottomed cylindrical shape with the other end closed, and a lid 22 that closes one end opening of the container body 21.
The container main body 21 integrally includes a cylindrical barrel portion 21a, a bottom portion 21b that closes the other end of the barrel portion 21a, and an outer flange portion 21c that projects radially outward from one end of the barrel portion 21a. The lid 22 has a plate shape. The lid body 22 here has a disc-shaped disc portion 22a that matches the outer periphery of the outer flange portion 21c. The lid body 22 has a through hole 22b for mounting the gas injection unit 6 in the center of the disc portion 22a. The lid 22 is provided with a fixing means (for example, a screw hole or a screw hole) for fixing the inner electrode unit 3, the electrical connection unit 5, and the gas injection unit 6.

  A seal packing 23 is disposed between the container body 21 (the outer flange portion 21c) and the lid body 22 (the disk portion 22a). The container main body 21 and the lid body 22 are fixed by a fixture 24 so that the airtightness inside the container 2 can be maintained. As an example, the fixture 24 includes a pair of clamping members that clamp the outer flange portion 21c and the disk portion 22a from the outside, and a bolt and a nut that adjust the interval between the clamping members.

(2) Inner electrode unit It demonstrates using FIGS. 3-7.
The inner electrode unit 3 includes one or more pairs of a long electrode 31 and a tubular dielectric 32 that covers the electrode 31.
The electrode 31 is formed of a metal (for example, stainless steel) cylinder. The electrode 31 has a space 31 a extending along the longitudinal direction and communicating with the outside of the container 2 inside. A space surrounded by the inner peripheral surface of the electrode 31 is the space 31a. The space corresponds to one aspect of the internal space according to the present invention.
The dielectric 32 is made of, for example, a glass tube. The cross section of the dielectric 32 has an annular shape. An electrode 31 is inserted in the central space of the dielectric 32. Here, the dielectric 32 is shorter than the electrode 31, and both ends in the longitudinal direction of the electrode 31 extend from the dielectric 32.

The inner electrode unit 3 includes a plurality of electrodes 31 covered with a dielectric 32. All of the plurality of electrodes 31 are attached to the lid body 22 of the container 2 via a fixture 33. One end of all the electrodes 31 is located outside the container 2, and a fixture 33 is fixed to a portion located outside the container 2, and the fixture 33 is fixed to the lid body 22.
The fixture 33 as an example has a columnar shape, has a through hole 33a on the center axis thereof, and has a threaded portion 33b on the outer peripheral surface. One end of the electrode 31 is inserted (fitted) into the through-hole 33a, and the screw portion 33b is screwed into the screw hole 22c of the lid body 22. In addition, the screw hole 22c may be provided in the through-hole of the cover body 22 over the full length, and may be provided only in the one end side (outer side) part of a through-hole.

The other ends of the multiple (30) electrodes 31 are supported by a support 34. As shown in FIGS. 3 and 4, the support body 34 is coupled to the lid body 22 via a coupling body 35.
The plurality of electrodes 31 are arranged so as to be positioned on the circumference as shown in FIG. 5 when all the electrodes 31 are viewed from the longitudinal direction of the electrodes 31. Here, the plurality of electrodes 31 are arranged at equal intervals in the circumferential direction. For this reason, the support body 34 as an example has an annular (for example, annular) annular portion 34a as shown in FIG.
As shown in FIGS. 6 and 7, the support 34 has a plurality of recessed portions 34 b in the annular portion 34 a in a portion that supports the electrode 31. The number of recessed portions 34b is the same as the number of electrodes 31. As shown in FIG. 7, the recessed portion 34b is recessed in a step shape. In the recessed portion 34b, the dielectric 32 is fitted into the large diameter portion 34c located on the entrance side (the lid body 22 side), and the electrode 31 is fitted into the small diameter portion 34d located on the far side from the large diameter portion 34c. Note that O-rings (elastic bodies) 36 are disposed at both ends of the dielectric 32 in the longitudinal direction.

Of the plurality of electrodes 31 arranged in an annular shape, two electrodes 31A and 31B adjacent in the circumferential direction are connected on the support 34 side so that the internal space 31a communicates as shown in FIG. Has been. Here, the support 34 is used. Note that the symbols “A” and “B” of the electrodes 31A and 31B are attached to indicate the electrodes 31 connected to each other.
As shown in FIGS. 6 and 7, the support 34 has a connecting path 34 e that connects the recessed portion 34 b for the electrode 31 </ b> A and the recessed portion 34 b for the electrode 31 </ b> B. The connecting path 34e is formed by integrating a first member having a through hole for the recessed portion 34b and a second member having a groove for the connecting path 34e by, for example, welding.
Thereby, the space 31a of the electrode 31 (31A, 31B) which makes two sets is connected, and the one communication path 79 is comprised (refer FIG. 7). One end of the electrode 31 </ b> A located on one end side of the one communication path 79 and one end of the electrode 31 </ b> B located on the other end side of the one communication path 79 are connected to the container 2 via the mounting tool 33. Located outside. Thereby, the cooling fluid can be flowed into the single communication path 79 from the opening on one end side of the electrodes 31A and 31B, and the fluid can be flowed out from the opening on the other end.

As shown in FIG. 6, the support body 34 is fixed to the connecting body 35 at a plurality of locations (for example, three locations) spaced in the circumferential direction. As shown in FIG. 4, the support body 34 has a fixing portion 34 f for fixing to the coupling body 35. The fixed part 34f extends radially inward and outward from the annular part 34a. This extended portion has a through hole 34g.
The support 34 is fixed to the connecting body 35 using a fixture. The fixture here is a screw body 91. The screw body 91 is inserted through the through hole 34 g of the fixing portion 34 f of the support body 34 and screwed into the screw hole 35 a of the connecting body 35. Note that one end (on the lid body 22 side) of the coupling body 35 is fixed to the lid body 22 by screwing a screw body 92 through the screw hole 22c of the lid body 22 into the screw hole 35b of the coupling body 35. Has been.

Here, the coupling body 35 has a plate shape. An imaginary line passing through the center of the connecting body 35 in the thickness direction intersects the circumference of the ring in which the plurality of electrodes 31 are arranged (see FIG. 6). Thereby, the substance arranged in the container 2 can be stirred. A recessed portion 35 c is provided on the outer peripheral side of the coupling body 35. As shown in FIG. 3, a gap is formed between the recessed portion 35 c and the body portion 21 a of the container body 21 of the container 2.
In addition, the part 35d in which the recessed part 35c of the outer peripheral side in the connection body 35 does not exist contact | connects or adjoins the internal peripheral surface of the trunk | drum 21a. Thereby, when the container 2 rotates, it can prevent that the position of the electrode 31 shifts | deviates.

(3) Outside Earth Electrode Unit This will be described with reference to FIG.
The outer ground electrode unit 4 is configured by a metal plate 41 disposed on the outer periphery of the body portion 21 a in the container 2. For example, stainless steel is used for the metal plate 41. The metal plate 41 is disposed along the entire circumference of the outer periphery of the trunk portion 21 a and is fixed by a fixture 42. A ring body 44 extending in the circumferential direction is attached to the fixture 42. As shown in FIG. 1B, two ring bodies 44 are arranged at intervals in the central axis direction of the container 2, and the roller bodies of the support unit 8 are arranged outside the central axis direction with respect to each ring body 44. 85 is located. Thereby, when the container 2 is rotated on the support unit 8, the container 2 can be prevented from being displaced in the central axis direction.

(4) Electrical connection unit The electrical connection unit 5 includes an inner connection unit 5A connected to the inner electrode unit 3 and an outer connection unit 5B connected to the outer ground electrode unit 4.

(4-1) Inner connection unit This will be described mainly with reference to FIGS. 3, 5 and 7.
The inner connection unit 5 </ b> A includes a power supply side connection subunit connected to the high voltage power supply, and an electrode side connection subunit that connects the power supply side connection subunit and the electrode 31 of the inner electrode unit 3. As the power supply side connection subunit, a gas injection unit 6 described later is used. That is, the gas injection unit 6 is made of a conductive material, and a power source is connected to the screw hole 623A that functions as a connection portion of the gas injection unit 6.

The electrode side connecting subunit is constituted by a metal plate 51 disposed on the outer surface of the lid 22 of the container 2.
The metal plate 51 is fixed to the lid body 22 in a state where the metal plate 51 is in contact with a fixture 33 for attaching the electrode 31 to the lid body 22. As shown in FIG. 7, the metal plate 51 has an annular portion 51a that is annular (here, circular). As shown in FIG. 6, the annular portion 51 a is provided with a through hole 51 b at a position corresponding to the fixture 33. The threaded portion 33b of the fixture 33 is inserted through the through hole 51b. The through hole 51b is larger than the screw portion 33b on the outer periphery of the fixture 33 and smaller than the nut body 53 screwed into the screw portion 33b. The annular portion 51 a is disposed between the nut body 53 and the lid body 22 which are screwed onto the outer periphery of the fixture 33 attached to the lid body 22. By rotating the nut body 53 so as to approach the lid body 22, the metal plate 51 (annular portion 51 a) is fixed to the lid body 22 in contact with the nut body 53.
The metal plate 51, the fixture 33, and the nut body 53 are made of a conductive material, and are electrically connected from the metal plate 51 to the electrode 31.

As shown in FIG. 5, the metal plate 51 integrally includes an extending portion 51 c that extends from the inner periphery of the annular portion 51 a toward the center of the annular portion 51 a. As shown in FIG. 8, the distal end portion of the extending portion 51c is curved in an “L” shape and has a through hole 51d. A screw body 93 for fixing the gas injection unit 6 to the lid body 22 is inserted into the through hole 51d. The screw body 93 is screwed into the screw hole 22d of the lid body 22.
The screw body 93 is made of a conductive material, and the gas injection unit 6 has conductivity. The screw body 93 is in contact with the gas injection unit 6 and the extending portion 51c. Thereby, the gas injection unit 6 is electrically connected to the metal plate 51.

  The annular portion 51 a has a through hole 51 e for fixing the metal plate 51 to the lid body 22. In addition, although the code | symbol of a through-hole is not shown in drawing, the code | symbol is attached | subjected in order to distinguish from another through-hole. As shown in FIG. 5, the through-hole 51 e is provided on the circumference where the plurality of electrodes 31 are arranged, and between the two screw bodies 92 for fixing the coupling bodies 35. The screw body 94 is inserted into the through hole 51e, and the screw body 94 is screwed into the screw hole 22f of the lid body 22.

(5) Gas injection unit The gas injection unit 6 has an introduction function of introducing the gas supplied from the gas supply source into the container 2. In addition to the introduction function, the gas injection unit 6 has a derivation function for deriving the gas circulated through the container 2 after being introduced into the container 2. The gas injection unit 6 also has an electrical connection function as a power supply side connection subunit constituting the inner connection unit 5A. The gas injection unit 6 is connected to a cooling fluid supply source and has a fluid supply function of supplying fluid to the fluid supply unit 7.
Hereinafter, a description will be given mainly with reference to FIG.
The gas injection unit 6 is composed of a plurality of subunits, for example.
The gas injection unit 6 includes a connection subunit 6A that is connected to a gas supply source and a fluid supply source, and an introduction / extraction subunit 6C that is attached to the container 2 and performs gas introduction and gas extraction.

(5-1) Connection Subunit The connection subunit 6A includes a connection body 61A that is connected to a gas supply source or a fluid supply source, and an adapter body 61B that is rotatably connected to the connection body 61A. The adapter body 61B is connected to the introduction / extraction subunit 6C.
(A) Connection body The connection body 61A has a bottomed cylindrical shape having a bottom portion 610A on one end side. The screw part 612A formed on the inner peripheral surface of the recess 611A of the bottom part 610A functions as a gas connection port. A through hole 614A is formed in the bottom portion of the recess 611A.
The inner periphery of the cylindrical portion 620A of the connecting body 61A is a step of spreading on the other end side having a small diameter portion 621A and a large diameter portion 622A. A screw hole 623A formed in the outer peripheral surface of the small diameter portion 621A functions as a connection portion connected to the power source. The screw portion 625A formed on the inner peripheral surface of the through hole 624A in the radial direction of the small diameter portion 621A functions as a fluid connection port.

(B) Adapter body The adapter body 61B has a cylindrical shape as a whole, and has an inner cylinder portion 611B, an outer cylinder portion 612B, and the other end side cylinder portion 613B in a state in which the central axes coincide with each other. In addition, the other end side cylinder part 613B connects the other end of the inner side cylinder part 611B and the outer side cylinder part 612B. The inner cylinder part 611B is longer than the outer cylinder part 612B, and a space 614B exists between the inner cylinder part 611B and the outer cylinder part 612B. The through hole 615B of the outer cylinder portion 612B communicates with the space 614B, and the screw portion 616B on the inner peripheral surface of the through hole 615B functions as a fluid supply connection port connected to the fluid supply unit 7 as shown in FIG. . In addition, a plurality of through-holes 615B are provided at intervals in the circumferential direction, here three (see FIG. 2).

(C) Assembly state A state where the connection body 61A and the adapter body 61B are combined will be described.
The inner cylinder portion 611B and the outer cylinder portion 612B of the adapter body 61B are inserted into the connection body 61A. At this time, a bearing 61E is provided between the large-diameter portion 622A of the connection body 61A and the outer cylindrical portion 612B of the adapter body 61B, and the adapter body 61B is rotatably supported with respect to the connection body 61A. The

  One end portion of the inner cylinder portion 611B of the adapter body 61B is fitted into the through hole 614A of the bottom portion 610A of the connection body 61A via the seal body 61D. As a result, a gas supply path 62 for supplying gas to the inlet / outlet subunit 6C including the gas connection port (screw portion 612A) is formed inside the inner cylinder portion 611B. In addition, a fluid is supplied to the fluid supply unit 7 including a small-diameter portion 621A of the connection body 61A, a space 614B inside the outer cylinder portion 612B of the adapter body 61B, and a fluid supply connection port outside the inner cylinder portion 611B. A fluid supply path 63 is formed.

(5-2) Introduction / Extraction Subunit The introduction / extraction subunit 6 </ b> C includes a main body 61 </ b> C that introduces gas into the inside of the container 2 and leads gas out of the container 2. The introduction / extraction subunit 6 </ b> C has an attachment body 62 </ b> C for attaching the main body 61 </ b> C to the container 2.
(A) Main Body The main body 61C is a columnar body, and a first recessed portion 611C that is recessed from one end surface and a second recessed portion 612C that is recessed from the other end surface are interposed via a through hole 614C of the intermediate wall portion 613C. Have in communication. Note that the size of the first recessed portion 611C is smaller than the size of the second recessed portion 612C.
The screw portion 615B formed on the peripheral surface of the first recessed portion 611C is screwed with the screw portion 617B on the outer periphery of the other end side cylinder portion 613B of the adapter body 61B.
A cylindrical body 63C communicating with the through hole 614C is attached to the intermediate wall 613C on the second recessed portion 612C side so as to extend into the container 2. Accordingly, gas is introduced from the first recessed portion 611C into the container 2 through the through hole 614C and the inside of the cylindrical body 63C.
A plurality of communication holes 616C communicating with the second recessed portions 612C are provided in the circumferential direction on one end side portion of the peripheral wall of the main body 61C. A filter 64C extending to the inside of the container 2 is attached to the opening side of the second recessed portion 612C. The gas flowing in the container 2 and flowing into the filter 64C is led out to the outside through the communication hole 616C from the flow path 64 between the second recessed portion 612C and the cylindrical body 63C.

(B) Attachment body The attachment body 62C has an outer flange portion 622C that projects outward from the other end portion of the cylinder portion 621C. A screw body 93 inserted through the through-hole 623C of the outer flange portion 622C is screwed into the screw hole 22d (see FIG. 4) of the lid body 22 of the container 2. A packing 65 is disposed between the attachment body 62 </ b> C and the lid body 22. The screw part 624C formed on the inner peripheral surface of the cylinder part 621C is screwed into the screw part 618C on the outer periphery of the main body 61C. An O-ring body 66 is disposed between the main body 61C and the attachment body 62C.

(6) Fluid supply unit The fluid supply unit 7 supplies the fluid to the electrode 31 of the inner electrode unit 3 using the gas injection unit 6. That is, the fluid supply unit 7 includes a supply path 7 a for supplying the fluid from the gas injection unit 6 to the electrode 31 of the inner electrode unit 3. As shown in FIG. 3, the fluid supply unit 7 is connected to the gas injection unit 6 via a connector 76 and a tube 77, and is connected to the electrode 31 via a tube 78.
The fluid supply unit 7 has an annular shape. Specifically, it has an annular shape corresponding to an annular shape in which a plurality of electrodes 31 are arranged. As shown in FIG. 2, the fluid supply unit 7 is arranged so as to overlap a plurality of electrodes 31 arranged in an annular shape when the unit is viewed from the longitudinal direction of the electrode 31.

Hereinafter, description will be made mainly with reference to FIG.
The fluid supply unit 7 includes a main body 71 having a circular groove 71a positioned on the central axis of a plurality of electrodes 31 arranged in an annular shape, a lid body 72 covering the groove 71a of the main body 71, and a gas injection unit. The tube 78 is connected to one end of one electrode 31 of one set (two pieces) constituting each communication passage 79 for cooling and the introduction pipe 73 connected to the 6-side tube 77 and having a communication passage to the groove 71a inside. And a lead-out pipe 74 having a communication path to the groove 71a inside. The main body 71 here has, for example, a rectangular cross section, and a groove 71a is recessed from the long side surface at one end toward the long side surface at the other end.
As shown in FIGS. 2 and 9, the lid 72 has an annular shape with a rectangular cross section. The lid 72 is integrated with the main body 71 by welding.

  A through hole 71 b for communicating with the introduction pipe 73 and a through hole 71 c for communicating with the outlet pipe 74 are provided at the bottom of the groove 71 a. That is, the introduction pipe 73 and the lead-out pipe 74 are connected to the long side surface of the main body 71 on the other end side. In addition, the end part on the main body 71 side of the introduction pipe 73 and the lead-out pipe 74 is a screw part, and is screwed into a screw hole (screw hole) using the through holes 71b and 71c.

Since the introduction pipe 73 is connected to a tube 77 extending in the radial direction from the fluid supply unit 7, it has an “L” shape. Since the outlet tube 74 is connected to the electrode 31 extending in the central axis direction via the tube 78, the outlet tube 74 has a straight tube shape.
There are three introduction pipes 73 spaced in the circumferential direction, and there are fifteen extraction pipes 74 spaced in the circumferential direction. For this reason, the fluid supply unit 7 is supported by connecting the introduction pipe 73 and the outlet pipe 74 to the gas injection unit 6 and the electrode 31 via the tubes 77 and 78.

(7) Support unit Description will be given mainly with reference to FIG.
The support unit 8 includes a pair of rollers 81 and 82, and the body portion 21 a of the container 2 is placed on the pair of rollers 81 and 82. One roller 81 is a drive roller connected to a drive motor. The other roller 82 is a passive roller that rotates through the container 2. Each of the rollers 81 and 82 is composed of two roller bodies 85 connected to the rotation shaft 83.
The rollers 81 and 82 here are in contact with the outer ground electrode unit 4 (metal plate 41) disposed on the peripheral surface of the container 2. By utilizing this, a metal plate (metal foil) is arranged on the outer peripheral surface of each of the rollers 81 and 82 to constitute the outer connection unit 5B.
3. Usage In the plasma processing apparatus 1 of the embodiment, since the container 2 for storing the substance to be processed is composed of the bottomed cylindrical container main body 21 and the lid 22, the temperature in the container 2 is increased during the plasma processing. It tends to rise. Most of the heat source is the positive electrode 31.
In the above configuration, when gas (air) is introduced into the space 31a existing in the longitudinal direction of the electrode 31, the temperature of the container 2 is 130 [° C.]. On the other hand, when the electrode 31 having the same structure is used and air is not allowed to flow into the electrode 31, the temperature in the container 2 is 150 [° C.]. Thus, by causing air to flow into the electrode 31, a temperature increase of 20 [° C.] can be suppressed.
The flow of air in the above test is about the air blowing and is room temperature air. Therefore, it is considered that there is a temperature rise suppressing effect of 20 [° C.] or more by increasing the flow rate of the cooled gas or gas.

Although the embodiment has been described above, the present invention is not limited to this embodiment, and for example, the following modification may be used. Further, the embodiment may be a combination of the modified example and the modified examples.
In addition, examples that are not described in the embodiments and modifications, and design changes that do not depart from the gist are also included in the present invention.

<Modification>
(1) In the embodiment, the inner electrode unit 3 is provided inside the container 2, and the outer ground electrode unit 4 is provided outside the container 2. However, glow discharge is used in the container that accommodates the substance to be plasma treated. As long as plasma can be generated, two electrode units may be provided in the container.
(2) In the embodiment, the outer ground electrode unit 4 is configured by the metal plate 51. However, for example, a rod-shaped electrode may be used as long as plasma using glow discharge can be generated.
(3) Although the inner electrode unit 3 includes the plurality of electrodes 31, a single electrode may be used.
(4) Although the electrode 31 of the inner electrode unit 3 uses one long object (hollow), for example, a plurality of metal cylinders may be connected to form one long electrode. In the embodiment, the other end of the single electrode 31 is supported by the support 34, but a plurality of electrodes may be connected in the longitudinal direction by a plurality of supports (a plurality of multiple supports are used as a plurality of electrodes). Book electrodes).
(5) The electrode 31 of the inner electrode unit 3 has a cylindrical shape having one space 31a inside the entire length, but one electrode has a plurality of spaces in the longitudinal direction. The fluid may flow in the middle. For example, the electrode includes two spaces in the longitudinal direction and communication holes communicating with the two spaces, and the fluid flows out of the first space and then flows into the second space. You may make it do. This can be done by coating the electrode with a tubular dielectric and allowing fluid to flow between the electrode and the dielectric.
(6) One end of the electrode 31 of the inner electrode unit 3 extends to the outside of the container 2 and can communicate with the outside. For example, the electrode is completely accommodated in the container, and fluid flows through the electrode. It is good also as a structure which can communicate with the exterior of a container using a tubular body.
(7) The electrode 31 of the inner electrode unit 3 is connected on the other end side in a state where the other electrode 31 communicates with the internal space 31a. However, three or more electrodes may be connected so that the internal space communicates. When the number to be connected is an odd number, the fluid may be discharged from the other end of the electrode to the outside of the container.
(8) In the embodiment, the two electrodes 31 are connected, the fluid is allowed to flow in from one end of the electrode 31 located outside the container 2, and the other electrode 31 is located at the end located outside the container 2. Fluid is flowing out from the part. However, the fluid may be flowed in from one end of the electrode and the fluid flowed out from the other end using the “U” -shaped electrode. In this case, the end of the electrode may be inside the container or outside the container.
(9) In the embodiment, the support body 34 is used to communicate the space inside the two electrodes 31. However, the support body 34 may be connected by a tube body or the like, for example.
(10) The plurality of electrodes 31 of the embodiment are arranged in an annular shape when viewed from the longitudinal direction, but may be arranged in a polygonal ring shape or an elliptical ring shape. A plurality of electrodes may be provided in a straight line.
(11) Although the plurality of electrodes 31 of the embodiment are provided on the lid body 22 constituting the container 2, electrodes may be provided on members arranged in the container.
(12) Although the plurality of electrodes 31 of the embodiment are provided on the lid 22 constituting the container 2, for example, the electrodes 31 may be provided on the bottom 21 b of the container body 21 constituting the container 2. In this case, a support body may be connected with the connection body attached to the container main body 21, and it is not necessary to connect.
(13) Although the support body 34 is connected by the plate-shaped connection body 35 in embodiment, you may connect by another shape, for example, a rod-shaped connection body.
(14) In the embodiment, the inner electrode unit 3 and the high voltage power source are connected, but an AC power source may be connected to the inner electrode unit and the outer electrode unit.
(15) The electrical connection unit (5), the gas injection unit (6), the fluid supply unit (7), and the support unit (8) may have any structure that can achieve the function of each unit. The structure may not be.

DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 2 Container 3 Inner electrode unit 4 Outer earth electrode unit (outer electrode unit)
5 Electrical connection unit 31 Electrode 31a Space (internal space)

Claims (7)

In the electrode unit for generating plasma by glow discharge in the container,
A long electrode;
A tubular dielectric covering the electrode, and
The electrode has a space extending along the longitudinal direction inside,
An electrode unit in which the space can communicate with the outside of the container. There are a plurality of the electrodes,
2. The electrode unit according to claim 1, wherein the spaces of two or more of the electrodes are connected to each other to form a single communication path communicating with the outside of the container. The end of the electrode located on one end side of the one communication path and the end of the electrode located on the other end side of the one communication path are located outside the container. Electrode unit. The number of the two or more is two,
The end of the electrode is one end of the electrode,
The other ends of the two electrodes are supported by a support in the container,
The support has a connection path that connects the spaces of the two electrodes in a communicating state.
The electrode unit according to claim 3. The plurality of electrodes are arranged on a virtual circumference when viewed from the longitudinal direction,
The electrode unit according to claim 4, wherein the two electrodes are adjacent in the circumferential direction. In a plasma processing apparatus for processing a substance by plasma generated by glow discharge between a pair of electrode units,
One of the pair of electrode units is the electrode unit according to any one of claims 1 to 5. A plasma processing apparatus. In a method for cooling a long electrode covered with a tubular dielectric and generating plasma by glow discharge in a container,
A method for cooling an electrode, wherein a fluid is caused to flow in an internal space extending along a longitudinal direction of the electrode.

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