JP2001217097A - High-frequency plasma device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize plasma ignition with ease in a simple structure even under the atmospheric pressure. SOLUTION: The device is composed of a bar electrode 7, a conductive bottom flange 3 supporting a discharge tube 2, and a high-voltage generating device 14 for impressing a high voltage between the bar electrode 7 and the bottom flange 3 and having the discharge tube 2 generate a discharge inside it. Otherwise, a discharge for a plasma ignition is made to generate between the bar electrode and a bottom cylindrical electrode provided at the bottom flange 3, or between the bottom cylindrical electrode and a top cylindrical electrode provided at a top flange part 4, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency plasma apparatus capable of easily igniting a plasma under atmospheric pressure.

[0002]

2. Description of the Related Art In a high-frequency plasma apparatus, an exciting current is applied to a high-frequency coil wound around an outer periphery of a discharge tube to generate an induction plasma inside the discharge tube, and a gas or a fine powder to be processed is generated in the induction plasma. And the like to execute predetermined processing. For example, it is used for plasma spraying to deposit and deposit solid powder injected into plasma as molten particles on a substrate, film formation of non-equilibrium material such as diamond, production of fine particles, or decomposition of organic halogen compounds such as chlorofluorocarbon. Have been.

[0003] The basic structure of a high-frequency plasma device consists of a discharge tube formed of an insulating material such as quartz or ceramics, and a high-frequency coil wound around the outer periphery of the discharge tube to generate induction plasma in the discharge tube. Have.

[0004] As means for igniting induction plasma,
For example, as disclosed in Japanese Patent Application Laid-Open No. 60-230399, there is a configuration in which an ignition rod is inserted into a discharge tube and induction heating is performed to facilitate plasma ignition. In addition, Japanese Unexamined Patent Publication
As disclosed in Japanese Patent Application Publication No. 1-68900, there is also known a configuration in which the inside of a discharge tube is decompressed to facilitate ignition.

[0005]

However, in the conventional apparatus using the above-mentioned igniting rod, a retracting means for keeping the igniting rod away from the plasma after ignition is required, which complicates the structure of the apparatus. Further, in the conventional apparatus for reducing the pressure in the discharge tube, a vacuum pump for reducing the pressure must be prepared, which involves a problem that the apparatus configuration becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its main object to provide a high-frequency plasma apparatus capable of easily firing plasma with a simple structure even under atmospheric pressure. I have.

[0007]

According to a first aspect of the present invention, an exciting current is applied to a high-frequency coil wound around the outer periphery of a discharge tube to generate an induced plasma inside the discharge tube. In a high-frequency plasma apparatus, a rod-shaped electrode and a conductive support for supporting the discharge tube are provided, and a high voltage is applied between the rod-shaped electrode and the support to generate a discharge in the discharge tube. It is characterized by.

According to a second aspect of the present invention, there is provided a high-frequency plasma apparatus for generating an induced plasma in a discharge tube by supplying an exciting current to a high-frequency coil wound around the outer periphery of the discharge tube. An upper support, a conductive lower support for supporting the lower part of the discharge tube, a first electrode provided on the upper support, or a second electrode provided on the lower support. Or an electrode portion composed of both, or between the first electrode and the lower support, between the upper support and the second electrode, or between the first electrode and the second electrode.
A high voltage is applied to any of the electrodes to generate a discharge in the discharge tube.

According to a third aspect of the present invention, in the high-frequency plasma apparatus according to the second aspect, a projection is provided at one or both of the first electrode and the second electrode.

[0010] The invention of claim 4 is the invention of claims 1 to 3.
In the high-frequency plasma device according to the, the rod-shaped electrode,
A cooling means for cooling the first electrode or the second electrode is provided.

[0011] The invention according to claim 5 is the invention according to claims 1 to 4.
In the high-frequency plasma device according to any one of the above, a discharge gap is provided in a circuit for supplying a high voltage from a high-voltage generator to the discharge tube.

According to a sixth aspect of the present invention, in the high frequency plasma apparatus according to the fifth aspect, a means for sealing the discharge gap with an insulating gas is provided.

According to a seventh aspect of the present invention, in the high frequency plasma apparatus according to the fifth aspect, means for blowing an insulating gas is provided between the discharge gaps.

According to an eighth aspect of the present invention, in the high frequency plasma apparatus according to the fifth aspect, the discharge gap is constituted by a water-cooled electrode.

According to a ninth aspect of the present invention, there is provided the first to fourth aspects.
The high-frequency plasma device according to any one of the above, wherein a high-frequency filter is provided in a circuit for supplying a high voltage from the high-voltage generator to the discharge tube. The high-frequency filter cuts off the high-frequency current generated by the excitation of the high-frequency coil and protects the high-voltage generator from burning and the like caused by the return of the high-frequency current.

According to a tenth aspect of the present invention, in the high frequency plasma apparatus according to any one of the first to fourth aspects, a circuit interrupting means is provided in a circuit for supplying a high voltage from a high voltage generator to a discharge tube. It is characterized by that. By this circuit cutoff means, the high-frequency current generated by the excitation of the high-frequency coil is mechanically cut off to protect the high-voltage generator from burnout or the like caused by the return of the high-frequency current.

An eleventh aspect of the present invention relates to a high-frequency plasma apparatus for generating an induction plasma inside a discharge tube by flowing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube.
A drying unit for drying the inside of the discharge tube is provided.

According to a twelfth aspect of the present invention, there is provided a high-frequency plasma apparatus for generating an induction plasma in a discharge tube by flowing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube.
The drying means is means for flowing a drying gas or a heated drying gas into the discharge tube.

According to a thirteenth aspect of the present invention, in the high-frequency plasma apparatus according to the eleventh aspect, the drying means heats the inside of the discharge tube with a heater. Specifically, it comprises a heater, a cylindrical heater block provided with the heater on the outer periphery, and a drive mechanism for driving the heater block movably in the axial direction of the discharge tube. The heater block is inserted into the discharge tube and dried by heating the heater. After the drying, the heater block is retracted out of the discharge tube by the driving mechanism.

According to a fourteenth aspect of the present invention, in the high frequency plasma apparatus according to the eleventh aspect, the inner wall surface of the discharge tube is
It is characterized by being water-repellent.

According to a fifteenth aspect of the present invention, in the high frequency plasma apparatus according to the eleventh aspect, the drying means is means for injecting a volatile solvent or an insulating fluid having a high affinity along the inner wall surface of the discharge tube. It is characterized by having.

According to a sixteenth aspect of the present invention, there is provided a high-frequency plasma apparatus for generating an induction plasma in a discharge tube by flowing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube.
At least one of the outer wall surface or the inner wall surface of the discharge tube,
It is characterized by comprising an insulating material having a low light transmittance.

According to a seventeenth aspect of the present invention, there is provided a high-frequency plasma apparatus for generating an induction plasma in a discharge tube by passing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube.
At least one of the outer wall surface or the inner wall surface of the discharge tube,
It is characterized in that a light-shielding means is provided, which is covered with an insulating material having a low light transmittance and shields light.

The invention according to claim 18 is a high-frequency plasma apparatus for generating an induced plasma in the discharge tube by flowing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube.
As a bottom structure of the lower support of the discharge tube, a seal member provided on the outer wall side of the lower end of the discharge tube, and a folded portion formed by bending the lower support along the inner wall of the lower end of the discharge tube, wherein the seal member And the folded portion sandwiches and supports the lower end of the discharge tube.

According to a nineteenth aspect of the present invention, in the high frequency plasma apparatus according to the eighteenth aspect, there is provided an overheating preventing means for cooling the lower support having the folded portion to prevent the sealing member from overheating. Features.

[0026]

FIG. 1 is a sectional view showing an embodiment of a high-frequency plasma apparatus according to the present invention.

The high-frequency plasma apparatus 1 shown in FIG. 1 has a discharge tube 2 formed in a cylindrical shape from an insulating material such as quartz or ceramics, a lower flange 3 serving as a base for supporting the discharge tube 2, An upper flange portion 4 covering the upper portion of the discharge tube 2, a disk portion 5 located on the upper surface of the upper flange portion 4, a lid portion 6 located on the upper surface of the disk portion 5 and covering the discharge tube 2, A rod-shaped electrode 7 provided substantially at the center of the lid 6,
A high frequency coil 8 wound around the outer circumference of the discharge tube 2 and a high frequency power supply 9 for supplying a high frequency exciting current to the high frequency coil 8 are provided. The lower flange portion 3 constitutes a lower support according to the second aspect, and the upper flange portion 4, the disk portion 5, and the lid portion 6 constitute an upper support according to the second aspect. Further, the lower flange part 3, the upper flange part 4, the disk part 5, and the lid part 5 are all made of a conductor such as stainless steel.

The discharge tube 2 has a double tube structure composed of an inner tube 2A and an outer tube 2B, and a water passage 10 is formed between the inner tube 2A and the outer tube 2B. A water inlet 11 is formed on the side surface of the lower flange portion 3 and a drainage hole 12 is formed on the side surface of the upper flange portion 12, so that cooling water introduced from the water inlet 11 rises in the water channel 11 to drain. It is configured to be discharged from the mouth 12 to the outside of the tube. This effectively cools the discharge tube 2 during the plasma processing.

A gas inlet 13 is formed in a side surface of the disk portion 5 constituting the upper support. At the start of discharge, argon gas or the like is introduced from the gas inlet 13 to promote plasma ignition. After the ignition, oxygen gas or nitrogen gas is introduced to stabilize the plasma, or a gas to be treated (including fine particles introduced together with the carrier gas) is introduced directly. Is done.

In the present embodiment, a high voltage generator 14 is connected between the rod-shaped electrode 7 and the lower flange 3. That is, the lower flange portion 3 which is a conductor also serves as the other electrode, and an arc discharge for plasma ignition is generated between the rod-shaped electrode 7 and the lower flange portion 3 when a high voltage is applied. The high voltage generator 14 is preferably a DC voltage generator or a pulse voltage generator. In this case, the DC voltage generating device has an advantage that the device can be formed compactly and inexpensively. The pulse voltage generator can be configured using an ignition coil, an induction Tesla coil, a spark gap coil, a rotary gap switch, a thyratron switch, etc., and can apply a relatively high voltage in a pulsed manner, so that arc discharge is easily generated, and Although it has the advantage that the fine adjustment of the discharge characteristics is easy, the device configuration is complicated and expensive.

<Other Examples Regarding Discharge Electrodes> In the above-described embodiment, the discharge electrodes are constituted by the rod-shaped electrodes 7 and the lower flange portions 3, but the combination of the discharge electrodes is not limited to this.

In the example shown in FIG. 2, a part of the upper flange portion 3, for example, an end of the disk portion 5 is extended downward to form the cylindrical electrode 21, and the disk portion 5 which is a conductor is formed. The high-voltage generator 14 (not shown in FIG. 2) is connected between the lower electrode 3 and a cylindrical electrode 21.
And an arc discharge is performed between the lower flange portion 3 and the lower flange portion 3. Thereby, the electric field intensity at the time of discharge increases, and an arc is easily generated in the discharge tube 2. Then, the high frequency plasma is easily generated as a trigger.
Therefore, high-frequency plasma can be easily generated without reducing the pressure inside the discharge tube 2.

In this case, the cylindrical electrode 21 is provided with a rectifying plate for rectifying the flow of the discharge stabilizing argon gas, reaction gas, gas to be treated, or a mixed gas thereof introduced from the gas inlet 13A or 13B. It becomes the structure which also serves.
For this reason, the gas introduced from the gas inlet 13A or 13B is rectified downward between the inner tube 2A and the cylindrical electrode 21 or along the inner surface of the cylindrical electrode 21 and flows therethrough. The arc discharge generated between the electrode 21 and the lower flange 3 is stabilized. Further, the rectification of the gas in the cylindrical electrode 21 also contributes to stabilization of the generated high-frequency plasma.

Further, as shown in FIG.
Are provided with projections 21A and 21B at the tip. The formation of the projections 21A and 21B improves the discharge characteristics. That is, the electric field is concentrated on the sharp projections 21A and 21B and the discharge characteristics are improved, so that plasma ignition is facilitated.

In the example shown in FIG. 4, the end of the lower flange portion 3 is extended upward to form a cylindrical electrode 22, and the cylindrical electrode 22 is provided between the disk portion 5 as a conductor and the lower flange portion 3. The high voltage generator 14 (not shown in FIG. 4) is connected to perform arc discharge between the disk portion 5 and the cylindrical electrode 22 of the lower flange portion 3.

Also, a projection 22A as shown in FIG. 3 is provided at the tip of the cylindrical electrode 22.
The discharge characteristics are improved by the formation of.

The example shown in FIG. 5 is a cylindrical electrode (also referred to as an "upper cylindrical electrode") in which the end of the disk portion 5 extends downward.
21 and a cylindrical electrode 22 (also referred to as a “lower cylindrical electrode”) having an end portion of the lower flange portion 3 extending upward. The high voltage generator 14 (not shown in FIG. 5) is connected to the section 3 to perform arc discharge between the upper cylindrical electrode 21 and the lower cylindrical electrode 22. is there.

Also in this case, projections 21A and 22A as shown in FIG. 3 are provided at the tips of both cylindrical electrodes 21 and 22, respectively. The formation of the projections 21A and 22A enables the electric field to be concentrated at the time of discharge, and the discharge characteristics are improved satisfactorily. The projections 21A and 22A are shown in FIG.
Are not limited to the shapes and numbers shown in FIG. The point is that any sharp tip may be used so that the discharge electric field is easily concentrated.

In the example shown in FIG. 6, an arc discharge is generated by connecting a high voltage generator 14 between the rod-shaped electrode 7 and the upper flange portion 4 or the disk portion 5 as the upper support. Things. That is, since the upper flange portion 4 and the disk portion 5 are conductors, it is necessary to electrically insulate the upper flange portion 4 and the disk portion 5 from the rod-shaped electrode 7. Therefore, the rod-shaped electrode 7 is replaced with an insulating material 25.
Is attached to the conductive lid portion 6 with an intervening member. As the insulating material, Teflon, glass epoxy resin, ceramics, or the like is preferable.

In the example shown in FIG. 7, an electrode 26 provided with a cooling water passage 27 therein is used as a rod-shaped electrode, and the electrode 26 is prevented from being heated at the time of discharge to minimize the consumption of the electrode. Things. As a result, the life of the electrode is dramatically extended.

The modified examples related to the electrodes have been described above with reference to FIGS. 2 to 7. However, the shapes of the electrodes provided on the lower flange portion 3 and the upper flange portion 4 are not limited to cylindrical shapes, One or a plurality of rod-shaped or needle-shaped electrodes may be formed at the end of the disk portion 5. In addition, the rod-shaped electrode 7
May be a pipe shape (hollow cylindrical shape).

<Protection Means of High Voltage Generator 14> The high voltage generator 14 applies a high voltage between the electrodes to generate an arc discharge in the discharge tube 2 and is used for igniting high frequency plasma. Is done. Therefore, the high voltage generator 14
After the plasma is generated, it is basically unnecessary except when the plasma becomes unstable and recovery is required. But,
The high-frequency power returns to the high-voltage generator 14 due to the induction current of the high-frequency coil 8, and the high-voltage generator 14 may be burned.

In order to prevent such a return of the high-frequency power, it is conceivable to insert an insulator such as an insulator between the high-voltage generator 14 and the rod-shaped electrode 7 or the flange serving as the electrode. . However, in this method, when a high voltage is applied, discharge occurs on the surface of the insulator, so that the surface of the insulator is deteriorated and insulation performance is deteriorated.

Therefore, as shown in FIG. 8, a discharge gap 31 is formed on the wiring connecting the rod-shaped electrode 7 and the high voltage generator 14.
Is provided to completely shut off the circuit, thereby preventing the return of the high-frequency current after the plasma is generated.

The discharge gap 31 is sealed in an insulating gas sealing device 32. The discharge is started between the discharge gaps 32 by the application of a high voltage from the high voltage generator 14. At this time, when the impedance between the gaps decreases, the discharge between the gaps continues, and as a result, the circuit becomes conductive. As a result, a high-frequency current flows from the high-frequency coil 8 side. In order to prevent this, the insulating gas is sealed to prevent the impedance from lowering and prevent the discharge from continuing between the gaps.

In the example shown in FIG. 9, a nozzle 34 connected to a gas supply device 33 is arranged near the discharge gap 31. When a discharge occurs, an insulating gas is blown from the nozzle 34 to quickly increase the impedance between the gaps, thereby promptly recovering the dielectric breakdown between the gaps, thereby preventing the inflow of the high-frequency current from the high-frequency coil 8 side. .

In the example shown in FIG. 10, a water cooling electrode 35 facing the discharge gap 31 is provided.
Then, cooling water is circulated to the water-cooled electrode 35 to prevent heating of the electrode and generation of metal vapor at the time of discharge, and to prevent continuation of discharge in the discharge gap 31.

In the example shown in FIG. 11, a high-frequency filter 41 is provided in place of the discharge gap 31 as shown in FIG. 8, and the return of the high-frequency current component is cut to prevent the high-voltage generator 14 from burning. It is something to do.

In the example shown in FIG. 12, a switch section 42 having mechanical contacts A and B and a conductor 43 connecting the contacts A and B is provided between the rod-shaped electrode 7 and the high voltage generator 4. I have. The conductor 43 of the switch section 42 is connected to a rod 44 and a drive mechanism 45 for vertically moving the rod. The drive mechanism 45 is turned on / off by a drive switch 46.
Is done.

In the above configuration, at the time of starting, the drive switch 46 is turned on, and the drive mechanism 45 turns on the conductor 43.
And the contacts A and B are brought into contact with each other to make them conductive, and the ignition switch 47 for high voltage generation 4 is turned on. This allows
A high voltage is applied to the rod-shaped electrode 7 from the high voltage generator 14 to generate an arc discharge and ignite the plasma. After the plasma ignition, the drive switch 46 is turned off, the drive mechanism 45 is driven to separate the conductor 43 from the contacts A and B, and the connection between the contacts A and B is cut off. As a result, the return of the high-frequency current from the plasma to the high-voltage generator 14 is blocked.

The example in which the high-frequency power generated by the exciting current of the high-frequency coil 8 is prevented from returning to the high-voltage generator 14 has been described with reference to FIGS. But,
For example, conductors (lower flange portion 3, upper flange portion 4, cylindrical electrodes 21 and 22) constituting the electrode portion of discharge tube 2
Etc.) and the high-frequency coil 8 are arranged such that the distance is adjusted so that the dielectric breakdown is caused by the high voltage generation from the high voltage generator 14 but not caused by the high-frequency power during ignition. It can also be solved.

<Drying Means in Discharge Tube 2> If there is moisture (moisture) inside discharge tube 2, plasma ignition becomes difficult. Therefore, it is necessary to keep the inside of the discharge tube 2 dry.

Therefore, as shown in FIG. 13, a dry gas supply device 52 is provided in parallel with the plasma gas supply device 51, and a dry gas is supplied from the dry gas supply device 52 into the discharge tube 2. Keep dry before firing plasma.

In the example shown in FIG. 14, a gas heating mechanism 53 for heating the drying gas generated from the drying gas generator 52 is provided.
And a more stable plasma ignition is realized by supplying the heated drying gas into the discharge tube 2.

In the example shown in FIG. 15, the inside of the discharge tube is heated by the heater 55. In this case, since the heater 55 is not always required, it is necessary to take the heater 55 out of the discharge tube 2. Therefore, in this example, a heater block 56 having a heater 55 is inserted into the tube by the driving mechanism 57 to dry the water droplets adhered to the inner wall during drying.
The inside is dried by heating according to 5. After the drying is completed, the driving mechanism 57 is operated to retract the heater block 56 out of the tube. Thereby, a dry state can be ensured, and plasma ignition can be performed favorably.

FIG. 16 shows a configuration in which a volatile solvent supply device 61 is provided, and a volatile solvent such as alcohol or acetone having a high affinity is supplied into the discharge tube 2 to evaporate water. As a result, the solvent remaining / adhering to the tube wall is
It dries quickly due to its volatility, and the drying time is shorter.

<Improvement of Insulation of Inner Wall of Discharge Tube> In the example of FIG. 17, an insulation fluid supply device 62 is provided, and an insulation fluid is supplied into the discharge tube 2 to improve the insulation of the wall surface 2. ing. Examples of the insulating fluid include pure water, florinate, various insulating oils, and the like. That is, if moisture or dirt adheres to the inner wall surface, good arc discharge does not occur.However, by causing the insulating fluid to flow uniformly on the inner wall surface, the occurrence of creeping discharge and the like can be prevented, resulting in efficient operation. Processing becomes possible.

In FIG. 18, the insulating fluid is circulated through a water channel 10 provided between the inner tube 2A and the outer tube 2B of the discharge tube 2, and the discharge tube 2 is cooled by the insulating fluid. It was done.

<Prevention of Deterioration of Discharge Tube 2> As a material for forming the discharge tube 2, a transparent glass such as quartz glass is often used. However, since such transparent glass transmits light, the outside of the discharge tube may be heated and deformed or damaged due to light absorption or the like.

For this reason, at least the inner tube 2A of the discharge tube 2
Made of silicon nitride has been proposed (Patent No. 2
530356). However, silicon nitride is expensive, and a discharge tube made of silicon nitride costs several to ten times or more as compared with that of quartz glass.

Therefore, in the embodiment of the present invention, the discharge tube 2
At least the inner tube 2A or the outer tube 2B is made of an insulating material having a low light transmittance, so that the discharge tube 2 is protected from the above-mentioned deterioration by ultraviolet rays.

In the example of FIG. 19, the discharge tube 2 made of quartz glass is used.
At least one of the inner tube 2A and the outer tube 2B is provided with a Teflon tape coating 65, which is an insulating material having a low light transmittance, as a light shielding means. Accordingly, light can be shielded with a simple configuration and at low cost, and deterioration such as heating, deformation, and damage of the discharge tube 2 due to light can be effectively prevented. It should be noted that the same effect can be expected by applying a Teflon coating or a ceramic coating to at least one of the inner surface and the outer surface of the inner tube 2A and the outer tube 2B instead of the Teflon tape coating 65.

<Insulation of High-Frequency Coil 8> FIG.
The surface of the high-frequency coil 8 is covered with an insulating material. Examples of the insulating material include a Teflon tape, a Teflon coating, and a ceramic coating. In this way, by covering the surface of the high-frequency coil 8 with the insulating material, dielectric breakdown on the coil surface (between the coil and the discharge tube, between the coil turns) when a high-frequency electric field is applied is prevented. be able to.

<Structure of Lower Flange 3> FIG. 21 shows the structure around the lower flange 3 in detail.

The lower flange portion 3 includes an inner tube 2A and an outer tube 2B.
From the bottom of the discharge tube 2 composed of a double tube, the inner tube 2A is fitted via an O-ring 71 and the outer tube 2B is fitted via an O-ring 72. In this case, since the inner tube 2A is exposed to a high temperature, the O-ring 71 is immediately deteriorated, so that it becomes impossible to maintain the confidentiality.

Therefore, in order to prevent the inner tube 2 from overheating and protect the O-ring, there is provided a folded portion in which the lower end of the discharge tube is folded in a U-shape on the outer tube side, and between the folded portion and the discharge tube outer tube. There is known an apparatus in which an O-ring is interposed in the device (see Japanese Patent Application Laid-Open No. 7-22194). However, bending the discharge tube formed of quartz glass or the like as in this device complicates the device configuration and is expensive.

In the embodiment of the present invention, as shown in FIG. 21, a bottom portion 3A of the lower flange portion 3 is formed with an L-shaped bent portion 73 inside the discharge tube, and the bent portion 73 and the inner tube 2A are formed. O-ring 71 and folded part 73
And sandwich it between. In addition, a coolant inlet / outlet 74 is formed in the side surface of the bottom portion, and the coolant is circulated through the entire bottom portion 3A of the lower flange portion 3 to prevent overheating of the O-ring 71 (an overheating prevention means of claim 19). In this case, as the inner tube 2A and the outer tube 2B of the discharge tube 2, a so-called straight tube having no general bent portion can be used as it is, and the configuration of the lower flange portion 3 is simplified, and the apparatus can be configured at low cost. In addition, assembly and disassembly can be easily performed.

[0068]

As described above, according to the present invention, plasma ignition can be easily performed even when the pressure is high, such as the atmospheric pressure, or with a simple apparatus configuration.

According to the fifth to tenth aspects of the present invention, the return of high-frequency power to the high-voltage generator due to the judo current of the high-frequency coil can be effectively blocked, and the high-voltage generator burns out. Etc. can be prevented beforehand.

According to the eleventh to fifteenth aspects of the present invention, since the drying means for drying the inside of the discharge tube is provided, it is possible to easily perform plasma ignition in the discharge tube.

According to the sixteenth and seventeenth aspects,
Since the external light on the wall surface of the discharge tube is effectively shielded, deterioration of the wall surface of the discharge tube can be effectively prevented even with a discharge tube made of inexpensive material such as quartz glass.

According to the eighteenth and nineteenth aspects,
With a simple device configuration, overheating of the seal member can be prevented, and the life of the device can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an embodiment of a high-frequency plasma device according to the present invention.

FIG. 2 is a sectional view showing an example of an electrode used in the high-frequency plasma device shown in FIG.

FIG. 3 is an explanatory diagram showing a tip configuration of an electrode.

FIG. 4 is a cross-sectional view showing another example of an electrode used in the high-frequency plasma device shown in FIG.

FIG. 5 is a sectional view showing still another example of an electrode used in the high-frequency plasma device shown in FIG.

FIG. 6 is a sectional view showing still another example of an electrode used in the high-frequency plasma device shown in FIG.

FIG. 7 is a sectional view showing still another example of an electrode used in the high-frequency plasma device shown in FIG.

FIG. 8 is a configuration diagram showing an example in which a discharge gap is sealed with an insulating gas as protection means of the high voltage generator.

FIG. 9 is a configuration diagram showing an example in which a discharge gap and a nozzle are used as protection means of the high voltage generator.

FIG. 10 is a configuration diagram showing an example in which a water-cooled electrode is used for a discharge gap of a protection means of a high-voltage generator.

FIG. 11 is a configuration diagram illustrating an example in which a high-frequency filter is used as protection means of a high-voltage generator.

FIG. 12 is a configuration diagram showing an example in which a mechanical switch unit is used as protection means of the high voltage generator.

FIG. 13 is a configuration diagram showing an example in which a drying gas is supplied as drying means for a discharge tube.

FIG. 14 is a configuration diagram showing an example in which heated drying gas is supplied as drying means for a discharge tube.

FIG. 15 is a configuration diagram illustrating an example of heater drying as drying means of the discharge tube.

FIG. 16 is a configuration diagram showing an example in which a volatile solvent is supplied as drying means for a discharge tube.

FIG. 17 is a configuration diagram showing an example in which an insulating fluid is supplied as drying means for a discharge tube.

FIG. 18 is a configuration diagram showing an example in which an insulating fluid is circulated in a water channel of a discharge tube.

FIG. 19 is a configuration diagram showing an example in which a Teflon tape coating is used as a light shielding means of a discharge tube.

FIG. 20 is a sectional view showing an example in which an insulating film is applied to a high-frequency coil.

FIG. 21 is a cross-sectional configuration diagram showing one configuration example of overheating prevention means provided on a lower flange portion of the high-frequency plasma device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency plasma apparatus 2 Discharge tube 2A Inner tube 2B Outer tube 3 Lower flange part (lower support) 4 Upper flange part (upper support) 5 Disk part (upper support) 6 Cover part (upper support) 7 Rod shape Electrode 8 High frequency coil 9 High frequency power supply 10 Water path 11 Water inlet 12 Drain 13 Gas inlet 14 High voltage generator 21 (Upper) cylindrical electrode (first electrode) 22 (lower) cylindrical electrode (second electrode) 21A, 22A, 21B, 22B Projection 25 Insulating material 27 Cooling water channel 31 Discharge gap 32 Insulating gas filling device 33 Gas supply device 34 Nozzle 35 Water cooling electrode 36 Cooling water supply device 41 High frequency filter 42 Switch section 43 Conductor 44 Rod 45 Drive mechanism 46 Drive switch 47 Ignition switch 51 Gas supply device for plasma 52 Gas supply device for drying 53 Gas heater Structure 55 Heater 56 Heater block 57 Drive mechanism 58 Heater power supply 61 Volatile solvent supply device 62 Insulating fluid supply device 65 Teflon tape coating 66 Insulating coating 71, 72 O-ring 73 Folding portion 74 Refrigerant inlet / outlet

Claims (19)

[Claims] 1. A high-frequency plasma apparatus for generating an induced plasma in a discharge tube by supplying an exciting current to a high-frequency coil wound around the outer periphery of the discharge tube, comprising: a rod-shaped electrode; and a conductive support for supporting the discharge tube. A high-frequency plasma apparatus comprising: a body; and applying a high voltage between the rod-shaped electrode and the support to generate a discharge in a discharge tube. 2. A high-frequency plasma apparatus for generating an induced plasma in a discharge tube by supplying an exciting current to a high-frequency coil wound around an outer periphery of the discharge tube, wherein the conductive upper support supports an upper portion of the discharge tube. A conductive lower support for supporting the lower portion of the discharge tube; and a first electrode provided on the upper support, a second electrode provided on the lower support, or both. An electrode portion comprising: a first electrode and a lower support; an upper support and a second support;
A high voltage is applied between the first electrode and the first electrode or between the first electrode and the second electrode to generate a discharge in the discharge tube. 3. The high-frequency plasma device according to claim 2, wherein a projection is provided on one or both of the first electrode and the second electrode. 4. The high-frequency plasma device according to claim 1, further comprising a cooling unit for cooling the rod-shaped electrode, the first electrode, or the second electrode. . 5. The high-frequency plasma apparatus according to claim 1, wherein a discharge gap is provided in a circuit for supplying a high voltage from a high-voltage generator to the discharge tube. High frequency plasma device. 6. The high-frequency plasma device according to claim 5, further comprising means for sealing the discharge gap with an insulating gas. 7. The high-frequency plasma device according to claim 5, further comprising means for blowing an insulating gas between the discharge gaps. 8. The high-frequency plasma device according to claim 5, wherein the discharge gap is constituted by a water-cooled electrode. 9. The high-frequency plasma device according to claim 1, wherein a high-frequency filter is provided in a circuit for supplying a high voltage from the high-voltage generator to the discharge tube. High frequency plasma device. 10. The high-frequency plasma apparatus according to claim 1, wherein a circuit interrupting means is provided in a circuit for supplying a high voltage from the high-voltage generator to the discharge tube. High frequency plasma equipment. 11. A high-frequency plasma apparatus for generating an induced plasma in an inside of a discharge tube by supplying an exciting current to a high-frequency coil wound around an outer periphery of the discharge tube, wherein drying means for making the inside of the discharge tube dry is provided. A high-frequency plasma device characterized by the above-mentioned. 12. The high frequency plasma apparatus according to claim 11, wherein said drying means is means for flowing a drying gas or a heated drying gas into a discharge tube. 13. The high-frequency plasma device according to claim 11, wherein the drying unit heats the inside of the discharge tube with a heater. 14. The high-frequency plasma device according to claim 11, wherein an inner wall surface of the discharge tube is water-repellent. 15. The high frequency plasma apparatus according to claim 11, wherein said drying means is means for injecting a volatile solvent or an insulating fluid having a high affinity along an inner wall surface of the discharge tube. High frequency plasma equipment. 16. A high-frequency plasma apparatus for generating an induced plasma in a discharge tube by supplying an exciting current to a high-frequency coil wound around the outer periphery of the discharge tube, wherein at least one of an outer wall surface and an inner wall surface of the discharge tube is
A high-frequency plasma device comprising an insulating material having a low light transmittance. 17. A high-frequency plasma apparatus for generating an induced plasma inside a discharge tube by flowing an exciting current through a high-frequency coil wound around the outer periphery of the discharge tube, wherein at least one of an outer wall surface and an inner wall surface of the discharge tube is
A high-frequency plasma apparatus comprising a light-shielding means for shielding light by covering with an insulating material having low light transmittance. 18. A high-frequency plasma apparatus for generating an induced plasma in an inside of a discharge tube by supplying an exciting current to a high-frequency coil wound around an outer periphery of the discharge tube, wherein a bottom structure of a lower support of the discharge tube is a discharge tube. A seal member provided on the outer wall side of the lower end, and a folded portion obtained by folding the lower support along the inner wall of the lower end of the discharge tube, wherein the seal member and the folded portion sandwich and support the lower end of the discharge tube. A high-frequency plasma device characterized by the above-mentioned. 19. The high-frequency plasma apparatus according to claim 18, further comprising an overheat preventing means for cooling the lower support having the folded portion to prevent the seal member from overheating. apparatus.