JP5055893B2 - Atmospheric pressure plasma generator - Google Patents

Description

  The present invention relates to an atmospheric pressure plasma generator for generating plasma in the vicinity of atmospheric pressure, and in particular, atmospheric pressure plasma that can stably and efficiently generate plasma while ensuring heat dissipation with a simple and compact configuration. It relates to a generator.

  As an atmospheric pressure plasma generator for generating plasma in the vicinity of atmospheric pressure (in the pressure range of 500 to 1500 mmHg), a gas is passed through the plasma torch, and a high frequency induction coil disposed around the plasma torch has a higher frequency than a high frequency power source. A high-frequency inductively coupled plasma generator that applies a voltage and blows out generated plasma from a plasma torch is known. In this high frequency inductively coupled plasma generator, since the high frequency induction coil becomes hot, the high frequency induction coil is constituted by a hollow pipe so that the cooling water flows inside it, and the cooling water is supplied before the plasma is ignited. In such a case, condensation occurs in the high-frequency induction coil, and therefore, an electromagnetic on-off valve is known in which cooling water is allowed to flow in accordance with plasma ignition (see, for example, Patent Document 1).

  The configuration of the atmospheric pressure plasma generator described in Patent Document 1 will be described with reference to FIG. A high frequency induction coil 62 made of a vip material is disposed around the plasma torch 61, and a high frequency voltage is applied to the high frequency induction coil 62 by a high frequency power source 63. A pipe 64a for supplying cooling water and a pipe 64b for discharging are connected to both ends of the high-frequency induction coil 62, and an electromagnetic on-off valve 65 is provided in the pipe 64a so that the cooling water flows only during plasma ignition. Yes.

  Further, as shown in FIG. 12, a cylindrical reaction tube 71 and a pair of electrodes 72a and 72b arranged around the tube are provided, a gas 73 is allowed to flow through the reaction tube 71, and a high frequency is generated between the pair of electrodes 72a and 72b. It is also known that a plasma is generated by applying an AC electric field of 1 KHz to 200 MHz with a power source 74 (the applied voltage may be a sine waveform, rectangular waveform, pulse waveform, etc.). (For example, refer to Patent Document 2). Further, in Patent Document 2, since the electrodes 72a and 72b generate heat when the frequency of the AC electric field increases, the refrigerant 75 is supplied from the supply pipe 76 into the electrodes 72a and 72b and discharged from the discharge pipe 77. It is described that it is cooled at the same time.

In addition, the applicant of the present application previously described in Japanese Patent Application No. 2006-149084, a plasma generation unit that generates primary plasma with a first inert gas, and a mixed gas of a second inert gas and a reactive gas as a primary plasma. An atmospheric pressure plasma generator has been proposed which includes a plasma expansion unit that generates a secondary plasma by being collided with each other and efficiently generates plasma.
Japanese Patent Laid-Open No. 2-135656 JP 2001-6897 A

  However, in Patent Document 1, since the high frequency induction coil 62 is cooled, the cooling water is handled in an environment where a high frequency voltage is used. Therefore, there is a risk of causing a short circuit or ignition due to water leakage, etc. In order to improve the performance, there is a problem that the configuration of the entire apparatus becomes complicated. Also in Patent Document 2, since the electrodes 72a and 72b are cooled by the refrigerant 75, there is a similar problem.

  In addition, since the apparatus configuration is complicated and large as described above, it is difficult to apply this apparatus to a use form in which this atmospheric pressure plasma generator is mounted on a moving apparatus such as a robot to perform plasma processing of various objects. In particular, since it is difficult to move the cooling device using the refrigerant, there is a problem that it cannot be moved substantially.

  And in the atmospheric pressure plasma generator having the plasma generator and the plasma expansion part previously proposed, it is necessary to prevent the coils, antennas and electrodes from becoming high temperature in the plasma generation part, and the plasma expansion part is provided. However, it is desired that a simple and compact configuration can be realized while the secondary plasma can be generated efficiently and stably.

  The present invention solves the above-described conventional problems. In the configuration including the plasma generation unit and the plasma expansion unit, an excessive temperature rise of the plasma generation unit can be surely prevented and the plasma expansion unit is efficiently stabilized. It is an object of the present invention to provide an atmospheric pressure plasma generator capable of generating secondary plasma and realizing a simple and compact configuration.

Atmospheric pressure plasma generating apparatus of the present invention, supply and tubular reactor interior forming the reaction space, the antenna or electrode disposed on the outer periphery of the reaction vessel, a first inert gas into the reaction space A plasma generating unit that has a first inert gas supply means that performs a high frequency electric power source that applies a high frequency electric field to the reaction space, and blows out a primary plasma made of the first inert gas that has been made plasma from the reaction space; A plasma expansion unit that forms a mixed gas region in which an appropriate amount of reactive gas is mixed with the second inert gas so that the primary plasma blown out from the space collides, and generates a secondary plasma composed of the plasma mixed gas When, and a heat radiating member having a gas supply passage to the mixed gas region with surrounding the reaction space of the plasma generating portion and to form a mixed gas region of the plasma expansion portion, the heat dissipation member A pair of split heat radiation members integrally formed by forming a recess having a semicircular cross section into which the outer peripheral surface of the reaction vessel is fitted, and a groove for accommodating the antenna or the electrode in close contact with the recess. It consists of.

  According to this configuration, since the heat radiating member surrounds the reaction space of the plasma generation unit, the heat generated by the antennas and electrodes around the reaction space can be effectively radiated to the outside through the heat radiating member and thermally damaged. It is possible to prevent the balance of the matching circuit from being lost due to increased resistance of the antenna and electrode, and the input of the high frequency power is reduced, so that the plasma intensity can be prevented from being lowered, thereby stably generating the primary plasma, In addition, the primary plasma collides with the mixed gas region, the second inert gas is turned into plasma in an avalanche phenomenon, and the reactive gas is turned into plasma by radicals of the second inert gas, etc. Secondary plasma can be generated efficiently at the development part, and since a heat radiating member is used without using a coolant such as cooling water as a cooling means, it can be made compact. In addition, since the mixed gas region and the gas supply path of the plasma expansion part are formed by the heat radiating member, the structure can be easily and compactly configured with the plasma expansion part, and the temperature for heat radiation can be further increased. Since the mixed gas region is formed by the raised heat dissipation member, the mixed gas region is stably maintained at an appropriate temperature and stable even when the generation of secondary plasma is stopped by stopping the supply of the mixed gas. Secondary plasma can be generated.

  In addition, if the heat dissipation member is made of a non-conductive heat dissipation member made of a material selected from alumina, sapphire, aluminum nitride, silicon nitride, boron nitride, and silicon carbide, insulation and thermal conductivity are high. High heat dissipation performance can be obtained, which is preferable.

  Further, if a mixed gas supply means for supplying a mixed gas in which the second inert gas and the reactive gas are mixed in advance is provided in the mixed gas region, the gas supply structure is simpler than when both gases are supplied separately. In addition, since the second inert gas and the reactive gas are mixed uniformly, a uniform plasma treatment can be realized as a whole.

  Further, if the second inert gas supply means for supplying the second inert gas to the mixed gas region and the reactive gas supply means for supplying the reactive gas to the mixed gas region are separately provided, the reactive gas is reduced. It can be mixed to an arbitrary concentration, and a desired plasma treatment can be performed.

  The first inert gas and the second inert gas may be different, but if the same kind of inert gas is used, the development of the secondary plasma is stabilized and the gas supply structure Is preferable because it becomes simple.

  In addition, the first inert gas and the second inert gas are preferably selected from argon, helium, xenon, neon, nitrogen, or one or more mixed gases thereof. . Although nitrogen gas is not literally an inert gas, it exhibits a behavior similar to that of the original inert gas in the generation of atmospheric pressure plasma, and can be used in substantially the same manner. It is assumed that the active gas contains nitrogen gas.

  In addition, a temperature detection unit that detects the temperature of the heat dissipation member, a forced cooling unit that cools the heat dissipation member, and a control unit that controls the operation of the forced cooling unit, the control unit detects the first temperature detected by the temperature detection unit. When the forced cooling means is operated when the temperature exceeds the set value, and the operation of the forced cooling means is stopped when the temperature is lower than the second set value set at a temperature lower than the first set value. In addition, the forced cooling when the heat-dissipating member exceeds the specified temperature ensures reliable and stable high cooling performance, and does not overcool and operates the forced cooling means only when necessary, saving energy Can be achieved.

  In addition, since the above atmospheric pressure plasma generator has a compact configuration, it can be mounted on a movable head that can move in the X, Y, and Z directions of the robot apparatus, thereby enabling plasma processing with extremely high versatility. It can be performed.

  According to the atmospheric pressure plasma generator of the present invention, the heat generated around the reaction space can be effectively radiated to the outside through the heat radiating member, and the primary plasma can be stably generated. Since the secondary plasma can be efficiently generated in the plasma developing part by colliding with the mixed gas region, and the heat radiating member is used as a cooling means without using a coolant such as cooling water. Since the gas supply path is formed with the mixed gas region of the plasma expansion part, the structure can be easily and compactly configured with the plasma expansion part. By being held stably, effects such as the ability to stably generate secondary plasma can be obtained.

  Hereinafter, each embodiment of the atmospheric pressure plasma generator of the present invention will be described with reference to FIGS.

(First embodiment)
First, a first embodiment of an atmospheric pressure plasma generator of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1A and 1B, a plasma head 1 as an atmospheric pressure plasma generator of the present embodiment includes a cylindrical reaction vessel 3 in which a reaction space 2 is formed, and a reaction vessel 3. An antenna 4 is provided along the outer periphery in the vicinity thereof, and the reaction vessel 3 constitutes a plasma generation unit. The antenna 4 is configured by winding a wire 5 in a coil shape having an inner diameter substantially equal to the outer diameter of the reaction vessel 3, and both ends of the wire 5 are extended to opposite sides, and through a matching circuit (not shown). Wirings 6a and 6b connected to a high frequency power source (not shown) are configured. As the wire 5, a metal having a low specific resistance value, for example, copper, silver, gold, aluminum, or the like is preferable, and copper is most preferable. As a high-frequency power source, the output frequency band is several kHz to several hundred KHz, an RF frequency band typified by 13.56 MHz, a VHF frequency band typified by 100 MHz, or 2.45 GHz used for a microwave oven. Although the thing of the microwave frequency band etc. which are represented can be used, 60 MHz-500 MHz are suitable.

  A block-shaped non-conductive heat radiating member 7 is disposed in contact with the reaction vessel 3 and the antenna 4 so as to surround the entire circumference thereof. The non-conductive heat radiating member 7 is a pair of divided heat radiating members each formed with a semicircular recess having a semicircular cross section into which the outer peripheral surface of the reaction vessel 3 is fitted and a spiral groove in which the antenna 4 is closely accommodated. It is comprised by the members 8 and 9. These pair of divided heat dissipating members 8 and 9 are disposed so as to surround the reaction vessel 3 and the antenna 4 disposed on the outer periphery thereof, and are integrally joined with a fastener such as a bolt or an adhesive, so that atmospheric pressure plasma is obtained. A generator 1 is configured. As the non-conductive heat radiating member 7, alumina, sapphire, aluminum nitride, silicon nitride, boron nitride, silicon carbide or the like is preferable because it has high insulation and thermal conductivity and high heat radiating performance can be obtained. Preferably, grease, sheet, adhesive or filling with high thermal conductivity is provided between the antenna 4 and the non-conductive heat radiating member 7 and between the divided heat radiating members 8 and 9 constituting the non-conductive heat radiating member 7. A heat transfer filler (not shown) such as an agent is interposed. Then, heat can be radiated from the antenna 4 to the non-conductive heat radiating member 7 more efficiently.

  The first inert gas 10 is supplied from the upper end 3 a of the reaction vessel 3 into the reaction space 2. In addition, plasma generated in the reaction space 2 is blown out as primary plasma 11 from the blowout port 3 b at the lower end of the reaction vessel 3. The non-conductive heat radiating member 7 extends long below the outlet 3b at the lower end of the reaction vessel 3, and has a mixed gas space 12 having a diameter larger than the reaction space 2 and opened at the lower end below the outlet 3b. In the upper part of the mixed gas space 12, a gas supply path 14 for supplying a mixed gas 13 composed of a second inert gas and an appropriate amount of reactive gas is formed. The mixed gas space 12 formed in the non-conductive heat radiating member 7 constitutes a plasma developing portion.

  In the above configuration, by supplying high-frequency power to the antenna 4 while supplying the first inert gas 10 from the upper end 3a of the reaction vessel 3, a dielectric magnetic field generated in the reaction space 2 by the high-frequency current flowing through the antenna 4 is generated. Thus, a part of ions and electrons are efficiently trapped by the inductive coupling method, and plasma is stably generated, and the plasma is blown into the mixed gas space 12 as the primary plasma 11 from the outlet 3b at the lower end of the reaction vessel 3. . In the mixed gas space 12, the mixed gas 13 is supplied from the gas supply path 14 to form a mixed gas region 15, and the primary plasma 11 collides with the mixed gas region 15. As a result, the second inert gas collided with the primary plasma 11 is converted into plasma in the avalanche phenomenon and spreads over the mixed gas region 15, and the reactive gas is generated by radicals of the second inert gas converted into plasma. Is formed into a plasma, and this secondary plasma 16 blows out from the lower end opening of the mixed gas space 12. Thus, the plasma processing can be efficiently performed by irradiating the surface of the workpiece with the blown-out secondary plasma 16.

  While the high-frequency current flows through the antenna 4 while the primary plasma 11 is generated, the antenna 4 generates heat and becomes high temperature. However, the non-conductive heat radiating member 7 is in contact with the antenna 4 and is thermally coupled. Therefore, the heat generated in the antenna 4 is effectively dissipated through the non-conductive heat radiating member 7, and the antenna 4 is effectively prevented from becoming an abnormally high temperature. Thus, the antenna 4 is damaged at an abnormally high temperature, or when the temperature is higher than a predetermined level, the resistance increases, the balance of the matching circuit (not shown) is lost, the reflected wave becomes stronger, and the input of high frequency power Can be eliminated, and the risk of a decrease in plasma intensity can be eliminated. Furthermore, since the mixed gas space 12 is formed by the non-conductive heat radiating member 7 that rises in temperature for heat dissipation, the mixed gas region 15 is stably maintained at an appropriate temperature, and the supply of the mixed gas 13 is stopped. Even when the generation of the secondary plasma 16 is stopped, the secondary plasma 16 can be generated stably.

  Further, since the heat dissipation mechanism is configured by the non-conductive heat dissipation member 7 and no coolant such as cooling water is used, the plasma head 1 can be configured easily and inexpensively, and the plasma head 1 is mounted on a moving device. By doing so, it is possible to perform plasma processing on various objects easily and at low cost.

  In the present embodiment, the above plasma head 1 is mounted on an atmospheric pressure plasma processing apparatus 21 as shown in FIG. The atmospheric pressure plasma processing apparatus 21 includes a robot apparatus 22 as a moving means capable of moving and positioning in three axis directions. The robot device 22 is configured by attaching a movable head 24 so as to be movable and positioned in a vertical direction (Z-axis direction) to a movable body 23 that can be moved and positioned in two axial directions (XY directions) orthogonal to each other in a horizontal plane. The plasma head 1 is installed on the movable head 24. On the other hand, the workpiece 25 is carried in / out by the carry-in / carry-out unit 27 to a position below the movable range of the plasma head 1 and is positioned and fixed at a predetermined position.

  As shown in FIGS. 3A and 3B, the processing object 26 is provided with a plurality of processing points 26 to be subjected to plasma processing in a plurality of places. As such an object to be processed 25, for example, as shown in FIG. 3A, an example of a circuit board 28 in which a land disposition area for mounting electronic components is a processing location 26, or as shown in FIG. There is an example of a flat panel display 29 such as a liquid crystal panel or a plasma display panel in which the anisotropic conductive film is attached to the processing portion 26, and the surface treatment of the land surface and the cleaning of the attachment surface are performed by plasma processing, respectively. It is.

  As shown in FIG. 4, the control configuration of the atmospheric pressure plasma processing apparatus 21 is a robot apparatus as a moving unit of the plasma head 1 based on an operation program and control data stored in the storage unit 32 in advance by the control unit 31. 22, the high-frequency power supply 17 and the flow rate control unit 34 that controls the gas supply from the gas supply unit 33 to the plasma head 1 are configured to control the operation. The control of the flow rate control unit 34 by the control unit 31 is a process start recognition unit 35 that recognizes the timing at which the plasma head 1 faces the processing location 26 of the workpiece 25, that is, the start and end of processing for the processing location 26. Based on the signal input from the processing end recognition means 36, the mixed gas space 12 is supplied to the mixed gas space 12 by the processing start signal to perform plasma processing on the processing location 26, and the mixed gas 13 is supplied by the processing end signal. The plasma processing for the processing location 26 is terminated by stopping the process. In the present embodiment, the process start recognizing unit 35 and the process end recognizing unit 36 are configured to recognize by comparing the control data stored in the storage unit 32 and the current position data from the robot apparatus 22. However, a means for recognizing when the plasma head 1 is opposed to the start point and end point of the processing location 26 may be provided.

  Specifically, the gas supply unit 33 and the flow rate control unit 34 are configured as shown in FIG. That is, the gas supply unit 33 includes a first inert gas supply source 37 that supplies the first inert gas 10, and a mixed gas source 38 that supplies the mixed gas 13 of the second inert gas and the reactive gas. And pressure regulating valves 37a and 38a are provided at the respective gas outlets. The first inert gas 10 is supplied to the reaction vessel 3 via a first flow rate control device 39 including a mass flow controller, and the mixed gas 13 is opened and closed with a second flow rate control device 40 including a mass flow controller. It is configured to supply the mixed gas space 12 via the control valve 41. The opening / closing control valve 41 and the first and second flow rate control devices 39 and 40 constitute a flow rate control unit 34 and are controlled by the control unit 31.

As the first and second inert gases, a single gas or a plurality of mixed gases selected from argon, neon, xenon, helium, and nitrogen are applied. As the reactive gas, oxygen, air, oxidizing gases such as CO ₂ and N ₂ O, reducing gases such as hydrogen and ammonia, and fluorine-based gases such as CF ₄ are applicable depending on the type of plasma treatment. Is done.

  Next, the plasma processing process of the processing location 26 of the workpiece 25 by the atmospheric pressure plasma processing apparatus 21 having the above configuration will be described. When the workpiece 25 is loaded and positioned at a predetermined position by the loading / unloading section 27, the robot apparatus 22 starts to operate, and the plasma head 1 is moved to the processing start point of the first processing spot 26 of the workpiece 25. Move towards. Further, the plasma head 1 starts to operate, and the primary plasma 11 is blown out from the blowout port 3b of the reaction vessel 3 into the mixed gas space 12, and this state is continuously maintained thereafter.

  In this state, when the plasma head 1 reaches the processing start point, a detection signal from the processing start recognizing means 35 is issued, the opening / closing control valve 41 is immediately opened, and the mixed gas 13 is supplied to the mixed gas space 12. The next plasma 16 is generated and the plasma processing of the processing location 26 is started. Thereafter, the plasma head 1 moves on the processing location 26 while maintaining the plasma processing state, so that the plasma processing of the processing location 26 is performed. When the plasma head 1 reaches the processing end point, a detection signal from the processing end recognition means 36 is issued, the opening / closing control valve 41 is immediately closed, the supply of the mixed gas 13 to the mixed gas space 12 is stopped, and the secondary operation is completed. The generation of the plasma 16 is stopped, the plasma processing is immediately stopped, and the plasma processing at the first processing portion 26 is completed. Thereafter, the subsequent processing locations 26 are sequentially plasma processed in the same manner, and when the plasma processing of all the processing locations 26 is completed, the workpiece 25 is unloaded at the loading / unloading unit 27 and the next workpiece 25 is loaded. In the same manner, plasma processing is performed.

(Second Embodiment)
Next, a second embodiment of the atmospheric pressure plasma generator of the present invention will be described with reference to FIG. In the following description of the embodiments, the same components as those in the preceding embodiment are denoted by the same reference numerals, description thereof will be omitted, and only differences will be mainly described.

  In the said 1st Embodiment, although the mixed gas space 12 formed in the nonelectroconductive heat radiating member 7 illustrated the cylindrical thing of a diameter larger than the reaction space 2, in this embodiment, as shown in FIG. The upper end of the mixed gas space 12 has a diameter close to the diameter of the reaction space 2 and is formed in a prefix cone shape whose diameter increases downward, and the gas supply passage 14 for supplying the mixed gas 13 is inclined obliquely downward. Let it form.

  According to the configuration of the present embodiment, since the upper end of the mixed gas region 15 and the outlet 3b at the lower end of the reaction vessel 3 substantially coincide with each other, the primary plasma 11 blown out from the outlet 3b is almost entirely over the upper part of the mixed gas. Since the collision occurs, the entire plasma of the mixed gas region 15 is more smoothly developed, and the secondary plasma 16 can be generated more efficiently.

(Third embodiment)
Next, a third embodiment of the atmospheric pressure plasma generator of the present invention will be described with reference to FIGS.

  In the first and second embodiments, the example in which the coiled antenna 4 is disposed has been shown. However, in the present embodiment, as shown in FIG. A pair of electrodes 42, 43 are arranged around the periphery with a predetermined interval, and a wiring 44 extending from the pair of electrodes 42, 43 is connected to the high-frequency power supply 17 through a matching circuit (not shown). In the atmospheric pressure plasma generator, as shown in FIG. 7A, the non-conductive heat radiating member 7 is disposed in contact with the electrodes 42 and 43.

  As shown in FIGS. 8A and 8B, the non-conductive heat radiating member 7 of the present embodiment includes a pair of split heat radiating members 8 and 9 having a recess 45 into which the outer peripheral surface of the reaction vessel 3 is fitted. An arc groove 46 that accommodates the electrodes 42 and 43 is formed in the recess 45, and a line groove 47 that leads out the wiring 44 is formed on the joint surface between the pair of divided heat radiation members 8 and 9.

  According to this embodiment, while supplying the first inert gas 10 to the reaction vessel 3, an AC electric field of 1 KHz to 200 MHz (a sign for the applied voltage is applied) between the pair of electrodes 42 and 43 by the high frequency power source 17. By applying a waveform, a rectangular waveform, a pulse waveform, or the like, plasma is generated in the reaction space 2 in the reaction vessel 3 and blown out as the primary plasma 11 from the blowout port 3b at the lower end. Impinges on the mixed gas region 15 formed by supplying the mixed gas 13 into the mixed gas space 12, and the mixed gas 13 is turned into plasma in the avalanche phenomenon and blown from the mixed gas space 12 as the secondary plasma 16. It's out. At that time, the heat generated in the electrodes 42 and 43 by the high-frequency current flowing in the electrodes 42 and 43 is effectively radiated to the outside through the non-conductive heat radiating member 7, so that the electrodes 42 and 43 become high temperature. It is possible to prevent the electrodes 42 and 43 from being damaged and the plasma output from being lowered as in the above embodiment. Further, the mixed gas region 15 is stably held at an appropriate temperature by the non-conductive heat radiating member 7 whose temperature rises for heat radiation, and the secondary plasma 16 can be stably generated.

(Fourth embodiment)
Next, a fourth embodiment of the atmospheric pressure plasma generator of the present invention will be described with reference to FIG. 9 and FIG.

  In the present embodiment, in the plasma head 1 of each of the above embodiments, as shown in FIG. 9, forced cooling means 51 for forcibly cooling the nonconductive heat radiating member 7 by the air cooling method, and the temperature of the nonconductive heat radiating member 7. A temperature detecting means 52 for detecting the power supply, a driving power supply 53 for the forced cooling means 51, a switch 54 for opening and closing the power supply, and a control unit 55 for controlling the opening and closing of the switch 54 by the temperature detected by the temperature detecting means 52. Yes.

  As shown in FIG. 10, the control unit 55 closes the switch 54 and operates the forced cooling unit 51 when the temperature detected by the temperature detecting unit 52 becomes equal to or higher than a preset upper limit set temperature Ta, and is set in advance. When the temperature becomes equal to or lower than the set lower limit temperature Tb, the switch 54 is opened to stop the operation of the forced cooling means 51.

  In the above configuration, the first inert gas 10 is introduced from the upper end 3 a of the reaction vessel 3, and a high frequency voltage is applied to the antenna 4 or the electrodes 42 and 43 disposed in the vicinity of the outside of the reaction vessel 3, thereby The plasma generated in the container 3 is blown out as the primary plasma 11 from the blowout port 3b, and this primary plasma 11 collides with the mixed gas region 15 formed by supplying the mixed gas 13 into the mixed gas space 12, and the mixing is performed. The gas 13 is converted into plasma in the avalanche phenomenon and blown out from the mixed gas space 12 as the secondary plasma 16. At that time, the antenna 4 or the electrodes 42 and 43 generate heat when a high-frequency current flows, but the heat is dissipated through the non-conductive heat radiating member 7 disposed in close contact with the antenna 4 or the electrodes 42 and 43. When the temperature of the non-conductive heat radiating member 7 is detected and the detected temperature becomes equal to or higher than the upper limit set temperature Ta, the forced cooling means 51 is operated to forcibly cool, and the lower limit is set. When the temperature becomes lower than Tb, the forced cooling means 51 is stopped to stop the forced cooling.

  As described above, according to the present embodiment, when the non-conductive heat radiating member 7 reaches a predetermined temperature or higher, it is possible to reliably and stably ensure high cooling performance by forcibly cooling, and without excessive cooling. Since forced cooling is performed only when necessary, energy saving can be achieved.

  In the description of each of the above embodiments, the example in which the antenna 4 and the electrodes 42 and 43 are cooled only by heat radiation by the non-conductive heat radiating member 7 has been described. 3), it is preferable that a higher heat dissipation performance is obtained. Further, the non-conductive heat radiating member 7 is not directly brought into contact with the device case (not shown), but another heat radiating plate (not shown) is arranged in surface contact with the non-conductive heat radiating member. A structure in which a heat sink is coupled to an apparatus case (not shown) may be employed. Moreover, a fin can be attached to an apparatus case (not shown) to increase the heat dissipation effect.

  In the above embodiment, the example in which the mixed gas obtained by mixing the second inert gas and the reactive gas in advance is supplied from the mixed gas source 38 to the mixed gas space 12 has been described. The second inert gas and the reactive gas may be separately supplied from the passage 14 and mixed with each other in the mixed gas space 12 to form the mixed gas region 15. Further, a second inert gas source and a reactive gas source are separately provided, and both are mixed at a desired mixing ratio via the flow rate control valve, and then the second flow rate control device 40 and the open / close control valve 41 in FIG. Alternatively, the mixed gas 13 may be supplied to the mixed gas space 12. Thus, if it supplies separately or provides a separate gas source, the mixing rate of reactive gas can be changed or adjusted arbitrarily.

  According to the atmospheric pressure plasma generator of the present invention, the heat generated around the reaction space can be effectively radiated to the outside through the heat radiating member, and the primary plasma can be stably generated. Since the secondary plasma can be efficiently generated in the plasma developing part by colliding with the mixed gas region, and the heat radiating member is used as a cooling means without using a coolant such as cooling water. Since the gas supply path is formed with the mixed gas region of the plasma expansion part, the structure can be easily and compactly configured with the plasma expansion part. Since the secondary plasma can be stably generated by being held stably, it can be suitably used for plasma processing of various objects to be processed.

The principal part structure of 1st Embodiment of the atmospheric pressure plasma generator of this invention is shown, (a) is a perspective view, (b) is an AA arrow line view of (a). The perspective view of the atmospheric pressure plasma processing apparatus to which the atmospheric pressure plasma generator of the embodiment is applied. The top view which shows two examples of a to-be-processed object. The block diagram which shows the control structure of the atmospheric pressure plasma processing apparatus. The block diagram of a gas supply part and a flow control part. The fragmentary sectional view which shows the principal part structure of 2nd Embodiment of the atmospheric pressure plasma generator of this invention. The principal part structure of 3rd Embodiment of the atmospheric pressure plasma generator of this invention is shown, (a) is a perspective view, (b) is a perspective view which shows a reaction tube and an electrode. The division | segmentation heat radiating member of the embodiment is shown, (a) is a front view, (b) is a perspective view. The perspective view which shows the principal part structure of 4th Embodiment of the atmospheric pressure plasma generator of this invention. Explanatory drawing of the control method of the cooling means of the embodiment. The block diagram of the atmospheric pressure plasma generator of a prior art example. The block diagram of the atmospheric pressure plasma generator of another prior art example.

Explanation of symbols

1 Plasma head (atmospheric pressure plasma generator)
2 Reaction space 3 Reaction vessel (plasma generator)
3b Outlet at the lower end 4 Antenna 7 Non-conductive heat radiating member 10 First inert gas 11 Primary plasma 12 Mixed gas space (plasma developing part)
DESCRIPTION OF SYMBOLS 13 Mixed gas 14 Gas supply path 15 Mixed gas area 16 Secondary plasma 21 Atmospheric pressure plasma processing apparatus 22 Robot apparatus 24 Movable head 51 Forced cooling means 52 Temperature detection means 55 Control part

Claims (8)

A cylindrical reaction vessel having an internal reaction space , an antenna or an electrode disposed on the outer periphery of the reaction vessel, and a first inert gas supply means for supplying a first inert gas to the reaction space; A plasma generator having a high-frequency power source for applying a high-frequency electric field to the reaction space and blowing out the primary plasma made of the first inert gas that has been made plasma from the reaction space, and the primary plasma blown out from the reaction space collide with each other. Forming a mixed gas region in which an appropriate amount of reactive gas is mixed with the second inert gas, and enclosing the plasma expansion part for generating the secondary plasma composed of the plasma mixed gas and the reaction space of the plasma generating part And a heat radiating member that forms a mixed gas region of the plasma developing portion and has a gas supply path to the mixed gas region ,
The heat dissipating member is formed of a pair of semicircular recesses into which the outer peripheral surface of the reaction container fits, and a groove for accommodating the antenna or the electrode in close contact with the recesses and integrally joined thereto. An atmospheric pressure plasma generator comprising a divided heat radiation member .   2. The atmospheric pressure plasma according to claim 1, wherein the heat dissipating member comprises a non-conductive heat dissipating member made of a material selected from alumina, sapphire, aluminum nitride, silicon nitride, boron nitride, and silicon carbide. Generator.   2. An atmospheric pressure plasma generator according to claim 1, further comprising a mixed gas supply means for supplying a mixed gas in which a second inert gas and a reactive gas are mixed in advance to the mixed gas region.   The second inert gas supply means for supplying the second inert gas to the mixed gas region and the reactive gas supply means for supplying the reactive gas to the mixed gas region are provided separately. The atmospheric pressure plasma generator according to 1.   2. The atmospheric pressure plasma generator according to claim 1, wherein the first inert gas and the second inert gas are the same kind of inert gas.   The first inert gas and the second inert gas are selected from argon, helium, xenon, neon, nitrogen, or one or more mixed gases thereof. The atmospheric pressure plasma generator according to any one of 1 to 5.   A temperature detecting means for detecting the temperature of the heat radiating member; a forced cooling means for cooling the heat radiating member; and a control part for controlling the operation of the forced cooling means. The control part detects the temperature detected by the temperature detecting means at a first set value. The forced cooling means is operated when the temperature becomes above, and the operation of the forced cooling means is stopped when the temperature becomes equal to or lower than a second set value set at a temperature lower than the first set value. Item 2. The atmospheric pressure plasma generator according to Item 1.   An atmospheric pressure plasma processing apparatus, wherein the atmospheric pressure plasma generation apparatus according to any one of claims 1 to 6 is mounted on a movable head movable in the X, Y, and Z directions of a robot apparatus.

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