JP2007227297A - Plasma generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To significantly reduce the manufacturing cost and operation cost of a plasma generating device by simplifying facilities for cooling a plume that is a plasmatized gas or a plasma generating nozzle as much as possible. <P>SOLUTION: A temperature rise suppression means 100A comprises a treatment gas cooler 101A for cooling treatment gas G supplied to the plasma generating nozzle 31; a chiller unit 102A; passages 103A and 104A for cooling water CW1 provided between the treatment gas cooler 101A and the chiller unit 102A; a treatment gas temperature measuring means 105A; and a gas temperature control circuit 97. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma generator for irradiating a plume, which is a plasma gas.

  As a plasma generator for irradiating a plume, which is a plasma gas, a plasma generation nozzle that receives a microwave propagating through a waveguide and turns the gas into a plasma based on the microwave energy is emitted. An equipped plasma generator is known.

  In such a plasma generation apparatus, generally, the plasma generation nozzle is heated by receiving heat from a plume, which is a plasma gas. Therefore, when Teflon (registered trademark) or the like is used as an insulating member for holding the electrode, it is required to keep the temperature of the plume or the plasma generating nozzle as low as possible.

  Similarly, since the workpiece is heated by receiving heat from the plume and the plasma generating nozzle, it is required to keep the temperature of the plume and the plasma generating nozzle as low as possible when the workpiece cannot withstand the high temperature.

  Therefore, various techniques have been proposed in which a cooling means for cooling the plume and the plasma generating nozzle is provided.

For example, Patent Document 1 discloses a liquid or gas waste treatment apparatus and treatment method in which a cooling water duct is provided at the nozzle tip of an electric plasma torch and the nozzle tip is cooled by cooling water flowing through the cooling water duct. The technology is disclosed.
Japanese Patent Laid-Open No. 7-19437

  However, in the technique of the liquid or gas waste processing apparatus and processing method disclosed in Patent Document 1 described above, not only the structure of the nozzle tip is complicated, but also the independent cooling water for cooling the plasma generating nozzle. Therefore, it is necessary to add new equipment such as a system to the apparatus, which increases the manufacturing cost and the operating cost of the plasma generator.

  The present invention has been made in view of the above problems, and it is possible to simplify the plume and plasma generation nozzles that are plasma gas, as much as possible, and to reduce the manufacturing cost of the plasma generation device. An object of the present invention is to provide a plasma generator capable of significantly reducing the operating cost.

  According to a first aspect of the present invention, there is provided a plasma generator, a microwave generator for generating a microwave, a waveguide for propagating the microwave, and a waveguide provided in the waveguide for receiving the microwave. A plasma generating nozzle for generating a plume, which is a plasma gas by converting a predetermined processing gas into a plasma based on the energy of the microwave, and discharging the plume, and the plume discharged from the plasma generating nozzle An irradiating plasma generator is characterized in that it includes a temperature rise suppression means for suppressing the temperature rise of the plume.

  According to this configuration, since the equipment for cooling the plasma generation nozzle can be simplified by suppressing the temperature increase of the plume by the temperature increase suppression means, the manufacturing cost and the operating cost of the plasma generation apparatus can be simplified. Can be greatly reduced. As a result, it is possible to provide a simple plasma generator with a small number of parts and less power.

  Here, it is desirable that the temperature rise suppression means includes a processing gas cooler that cools the processing gas supplied to the plasma generation nozzle.

  According to this configuration, since the temperature rise suppression means includes the processing gas cooler that cools the processing gas supplied to the plasma generating nozzle, the plume that is a gas converted into plasma by the cooled processing gas is removed. As a result of being able to cool, it is not necessary to newly provide an independent system of cooling fluid for cooling the plasma generating nozzle. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Further, since the processing gas is directly cooled, the response characteristic of the plume temperature control is good.

  Next, it is desirable that the processing gas cooler cools the processing gas supplied to the plasma generation nozzle by cooling water.

  According to this configuration, since the plume is cooled by the processing gas cooled by the cooling water, the heat exchange amount can be easily adjusted by changing the amount of the cooling water in the processing gas cooler to adjust the temperature of the plume. Will be able to.

  In addition, it is desirable that the processing gas cooler includes a cooling element and cools the processing gas supplied to the plasma generation nozzle by the cooling element.

  According to this configuration, since the plume is cooled by the processing gas cooled by the cooling element, the amount of heat exchange can be easily adjusted by changing the heat load of the cooling element in the processing gas cooler, and the temperature of the plume can be adjusted. Can be adjusted.

  Preferably, the cooling element is a Peltier element, and the process gas supplied to the plasma generating nozzle is cooled by passing a current through the Peltier element.

  According to this configuration, since the processing gas can be easily cooled by passing a current through the Peltier element provided in the processing gas cooler, the controllability of the plume temperature control can be further improved. .

  The temperature increase suppression means may include a cooling channel provided in the plasma generation nozzle, and the plasma generation nozzle may be cooled by a refrigerant flowing through the cooling channel.

  According to this configuration, since the plasma generating nozzle is cooled by the refrigerant flowing through the cooling channel and the plume is indirectly cooled, the plume temperature is gently controlled while the plume is maintained in a stable state. be able to.

  Here, as the refrigerant, it is desirable to employ a processing gas supplied to the plasma generating nozzle.

  According to this configuration, since the refrigerant is the processing gas supplied to the plasma generation nozzle, there is no need to newly provide an independent system of cooling fluid for cooling the plasma generation nozzle. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Alternatively, the refrigerant may employ a microwave absorbing medium used to absorb microwave energy in a dummy load provided in the waveguide (claim 8).

  According to this configuration, since the microwave absorbing medium used to absorb the microwave energy in the dummy load is used as the refrigerant, similarly, an independent system of cooling fluid for cooling the plasma generating nozzle is newly added. There is no need to provide it. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Alternatively, the temperature rise suppression means includes plasma power changing means capable of changing the plasma power of the microwave generating means, and the plasma power changing means reduces the plasma power of the microwave generating means, thereby reducing the plume. You may comprise so that it may cool (Claim 9).

  According to this configuration, since the plasma power changing means of the temperature rise suppressing means cools the plume by reducing the plasma power of the microwave generating means, an independent system of cooling fluid for cooling the plasma generating nozzle Need not be provided separately. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Further, since the plume is cooled by reducing the plasma power, the response characteristic of the plume temperature control is good.

  The plasma generation nozzle preferably includes temperature measuring means for measuring the temperature of the plume or the plasma generation nozzle.

  According to this configuration, since the plasma generating nozzle includes the temperature measuring means for measuring the temperature of the plume or the plasma generating nozzle, the temperature of the plume or the plasma generating nozzle is monitored and the temperature of the plasma is set to a predetermined temperature. By adjusting, it becomes possible to maintain a stable surface modification effect and organic matter removal effect over a long period of time regardless of the season, weather, time or the like.

  As described above, according to the configuration of the plasma generation apparatus according to the present invention, the plume or plasma generation nozzle, which is a plasma gas, is cooled directly or indirectly, so that the workpiece can be maintained at a low temperature. As a result, a predetermined process such as surface modification and organic substance removal can be performed without impairing the quality of the work, such as the work being burnt or burning.

  Further, since the plasma generating nozzle is cooled, the temperature around the nozzle portion does not become excessively high, and it is possible to prevent, for example, softening of Teflon (registered trademark) that is an insulating material of the electrode. As described above, since it is possible to prevent dimensional change and softening of the parts due to high heat, the life of the plasma generating nozzle can be extended and used for a long time.

  According to the plasma generator of the first aspect, the equipment for cooling the plasma generation nozzle can be simplified by suppressing the temperature increase of the plume by the temperature increase suppression means. The manufacturing cost and the operating cost can be greatly reduced. As a result, it is possible to provide a simple plasma generator with a small number of parts and less power.

  According to the plasma generating apparatus of the second aspect, since the temperature rise suppression means includes the processing gas cooler that cools the processing gas supplied to the plasma generating nozzle, the plasma generating apparatus is converted into plasma by the cooled processing gas. As a result, it is not necessary to provide a separate independent system of cooling fluid for cooling the plasma generating nozzle. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Further, since the processing gas is directly cooled, the response characteristic of the plume temperature control is good.

  According to the plasma generating apparatus of the third aspect, the plume is cooled by the processing gas cooled by the cooling water. Therefore, the heat exchange amount can be easily adjusted by changing the amount of the cooling water in the processing gas cooler. The plume temperature can be adjusted.

  According to the plasma generating apparatus of the fourth aspect, the plume is cooled by the processing gas cooled by the cooling element. Therefore, the heat exchange amount can be easily adjusted by changing the thermal load of the cooling element in the processing gas cooler. Then the plume temperature can be adjusted.

  According to the plasma generator of the fifth aspect, since the processing gas can be easily cooled by passing a current through the Peltier element provided in the processing gas cooler, the controllability of the plume temperature control is further improved. Can be a thing.

  According to the plasma generating apparatus of the sixth aspect, the plasma generating nozzle is cooled by the refrigerant flowing through the cooling channel and the plume is indirectly cooled, so that the plume is maintained in a stable state while maintaining the plume. Temperature control can be performed gently.

  According to the plasma generating apparatus of the seventh aspect, since the refrigerant is the processing gas supplied to the plasma generating nozzle, there is no need to newly provide an independent system of cooling fluid for cooling the plasma generating nozzle. . As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  According to the plasma generating apparatus of the eighth aspect, since the microwave absorbing medium used for absorbing microwave energy in the dummy load is used as the refrigerant, similarly, the cooling fluid for cooling the plasma generating nozzle is used. There is no need to provide a new independent system. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  According to the plasma generating apparatus of the ninth aspect, the plasma power changing means of the temperature rise suppressing means cools the plume by lowering the plasma power of the microwave generating means, so that the plasma generating nozzle is cooled. There is no need to provide a separate independent cooling fluid system. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Further, since the plume is cooled by reducing the plasma power, the response characteristic of the plume temperature control is good.

  According to the plasma generating apparatus of the tenth aspect, since the plasma generating nozzle includes the temperature measuring means for measuring the temperature of the plume or the plasma generating nozzle, the temperature of the plume or the plasma generating nozzle is monitored to By adjusting the temperature to a predetermined temperature, it is possible to maintain a stable surface modification effect and organic matter removal effect over a long period of time regardless of the season, weather, time, or the like.

  As described above, according to the configuration of the plasma generation apparatus according to the present invention, the plume or plasma generation nozzle, which is a plasma gas, is cooled directly or indirectly, so that the workpiece can be maintained at a low temperature. As a result, a predetermined process such as surface modification and organic substance removal can be performed without impairing the quality of the work, such as the work being burnt or burning.

  Further, since the plasma generating nozzle is cooled, the temperature around the nozzle portion does not become excessively high, and it is possible to prevent, for example, softening of Teflon (registered trademark) that is an insulating material of the electrode. As described above, since it is possible to prevent dimensional change and softening of the parts due to high heat, the life of the plasma generating nozzle can be extended and used for a long time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of the plasma generator S1 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the overall configuration of the plasma generator S1 according to the first embodiment. It is. 3 is a side view showing the configuration of the plasma generation nozzle 31 of the plasma generation apparatus S1 according to the first embodiment, and FIG. 4 is a plasma generation nozzle of the plasma generation apparatus S1 according to the first embodiment. FIG. FIG. 5 is a conceptual diagram showing the configuration of the temperature rise suppression means 100A of the plasma generator S1 according to the first embodiment. In FIG. 1, the XX direction is the front-rear direction, the YY direction is the left-right direction, the ZZ direction is the up-down direction, the -X direction is the front direction, the + X direction is the rear direction, and -Y is the left direction. In the following description, the + Y direction is the right direction, the -Z direction is the downward direction, and the + Z direction is the upward direction.

  As shown in FIG. 1, the plasma generator S1 according to the first embodiment of the present invention is a transport means C for transporting a workpiece W along a predetermined route, and a workpiece to be transported by the transport means C. The workpiece W includes a plasma generation unit PU that irradiates plasma.

  The conveying means C includes a plurality of conveying rollers 80 arranged along a predetermined conveying path, and the conveying rollers 80 are driven by a driving means (not shown) to generate a plasma on the workpiece W to be processed. It is conveyed via the section 30. In the present embodiment, a flat substrate such as a semiconductor substrate, a circuit substrate on which electronic components are mounted, or a flat work W such as a plasma display panel is conveyed as a processing target.

  The plasma generation unit PU is a unit capable of generating plasma at room temperature and normal pressure by converting the plasma processing gas G (FIG. 3) into plasma based on microwave energy and propagating the microwave. A waveguide 10, a microwave generator 20 (corresponding to microwave generation means) that is disposed on one end side (left side) of the waveguide 10 and generates a microwave having a predetermined wavelength, and provided in the waveguide 10 The plasma generator 30 is provided.

  Further, in the present embodiment, the plasma generation unit PU is provided with a temperature rise suppression means 100A (FIG. 5) that suppresses the temperature rise of the plume P, in particular.

  Further, the plasma generation unit PU is provided as a supplementary equipment, a sliding short 40 disposed on the other end side (right side) of the waveguide 10 to reflect the microwaves, and a reflection of the microwaves emitted to the waveguide 10. A circulator 50 that separates the microwave so as not to return to the microwave generator 20, a dummy load 60 that absorbs the reflected microwave separated by the circulator 50, and a stub tuner 70 that performs impedance matching are provided.

  The waveguide 10 propagates the microwave generated by the microwave generator 20 in the longitudinal direction toward the plasma generator 30. In this embodiment, the microwave generator 20 is mounted. The first waveguide piece 11, the second waveguide piece 12 to which the stub tuner 70 is assembled, and the third waveguide piece 13 in which the plasma generator 30 is provided.

  In the present embodiment, the first waveguide piece 11, the second waveguide piece 12, and the third waveguide piece 13 are respectively an upper surface plate made of a nonmagnetic metal plate such as aluminum, and a lower plate. It is composed of a long tube having a rectangular cross section formed in a rectangular tube shape using a face plate and two side plates and having flange plates attached to both ends thereof. And the 1st waveguide piece 11 which consists of these long tubes, the 2nd waveguide piece 12, and the 3rd waveguide piece 13 are connected with a mutual flange board, but at this time, A circulator 50 is interposed between the first waveguide piece 11 and the second waveguide piece 12, and a sliding short 40 is connected to the other end side of the third waveguide piece 13.

  In the present embodiment, the microwave generation device 20 (corresponding to the microwave generation means) is a continuously variable microwave generation source capable of outputting a microwave having a frequency of 2.45 GHz and an output energy of 1 W to 3 kW. An apparatus main body 21 having both an amplifier for adjusting the intensity of the microwave generated by the wave generation source to a predetermined output intensity, and the microwave generated by the apparatus main body 21 inside the waveguide 10 A microwave transmitting antenna 22 (FIG. 2) that emits light to the first waveguide piece 11 is fixed.

  As shown in FIG. 2, the microwave generator 20 has a device body 21 placed on the upper surface plate 11U of the first waveguide piece 11 and a microwave transmitting antenna 22 formed in the upper surface plate. The first waveguide piece 11 is fixed to the waveguide space 110 inside the first waveguide piece 11 through the hole 111.

  With this configuration, the microwave emitted from the microwave transmission antenna 22 is propagated from the one end side (left side) to the other end side (right side) by the waveguide 10.

  The plasma generator 30 is provided in the third waveguide piece 13 (waveguide 10), receives a microwave, generates a plume P, which is a plasma gas based on the energy of the microwave, and emits it. A plasma generating nozzle 31 is provided. The plasma generation nozzle 31 is configured to irradiate the plume P onto the workpiece W to be processed to perform a predetermined process.

  As shown in FIGS. 3 and 4, the plasma generation nozzle 31 includes a nozzle holder 34, a nozzle body 33, a seal member 35, an internal conductor 32, and a rotation provided at the tip of the plasma generation nozzle 31. And a possible rotating plate 36.

  First, the nozzle holder 34 is a cylindrical body of a highly conductive metal provided to hold the nozzle body 33, and is welded to a through hole 131 drilled in the lower surface plate 13 </ b> B of the third waveguide piece 13. ing.

  A pair of gas supply holes 344 for supplying the processing gas G to the plasma generating nozzle 31 are formed on the outer periphery of the nozzle holder 34 to connect a terminal portion of a gas supply pipe for supplying a predetermined processing gas G. A pipe joint is attached.

  The nozzle body 33 is a cylindrical body of a highly conductive metal that is fitted to the nozzle holder 34 from below, and is fitted to the nozzle holder 34 and the annular recess 33S for holding the gas seal ring 37 in order from the top. The upper body portion 33U and a flange portion 33F projecting in an annular shape are provided. In addition, a communication hole 333 for supplying a predetermined processing gas G to the cylindrical space 332 is formed in the upper body portion 33U.

  The nozzle body 33 functions as an external conductor disposed around the internal conductor 32. The outer peripheral portion of the nozzle main body 33 is in contact with the inner peripheral wall of the nozzle holder 34, and the upper end surface of the flange portion 33F is The nozzle holder 34 is fitted to the lower end edge of the nozzle holder 34. Although not shown, the nozzle body 33 is mounted with a fixed structure that is detachable from the nozzle holder 34 using, for example, a plunger or a set screw.

  The gas supply hole 344 of the nozzle holder 34 and the communication hole 333 of the nozzle body 33 are set so that they are in communication with each other when the nozzle body 33 is fitted into the nozzle holder 34 at a fixed position. Has been. A gas seal ring 37 is interposed between the nozzle body 33 and the nozzle holder 34 in order to suppress gas leakage from the abutting portion between the gas supply hole 344 and the communication hole 333.

  The seal member 35 is a cylindrical body made of a heat-resistant resin material such as Teflon (registered trademark) or an insulating member made of ceramic or the like having a holding hole 351 on the central axis for holding the internal conductor 32 in a fixed manner. is there.

  The seal member 35 is held on the upper portion of the nozzle holder 34 in such a manner that the lower end edge thereof is in contact with the upper end edge of the nozzle body 33 and the upper end edge thereof is in contact with the upper end engaging portion 345 of the nozzle holder 34. That is, the seal member 35 in a state of supporting the internal conductor 32 is assembled so that the lower end edge is pressed by the upper end edge of the nozzle body 33.

  The internal conductor 32 is a rod-shaped member made of a highly conductive metal, and is provided so that one end protrudes inside the third waveguide piece 13 (waveguide 10). And the receiving antenna part 320 provided so that one end may protrude inside this 3rd waveguide piece 13 receives the microwave which propagates the inside of the waveguide 10, and microwave energy is given. It has become. The internal conductor 32 is held by a seal member 35 at a substantially intermediate portion in the length direction.

  The nozzle holder 34, the nozzle body 33, and the third waveguide piece 13 are in a conductive state (the same potential), while the internal conductor 32 is supported by an insulating seal member 35 and is electrically insulated. Has been. Accordingly, the counter electrode of the internal conductor 32 is formed on the nozzle body 33 in a state where the third waveguide piece 13 is at the ground potential. When microwaves are received by the receiving antenna portion 320 of the internal conductor 32, microwave power is supplied to the internal conductor 32, and an electric field concentration portion is formed between the lower end portion 322 and the nozzle body 33. A plume is generated.

  The plasma generating nozzle 31 is provided with a temperature measuring means 39 composed of a thermocouple at the tip of the plasma generating nozzle 31 as shown in FIG. 9 in order to measure the temperature of the plume P or the plasma generating nozzle 31. The temperature of the plume P or the plasma generating nozzle 31 can be adjusted by the temperature measuring means 39 and the temperature rise suppressing means 100A described below.

  Here, the temperature rise suppression means 100A of the plasma generation nozzle 31 will be described. As shown in FIG. 5, in this embodiment, the temperature rise suppression means 100A that cools the processing gas G supplied to the plasma generation nozzle 31 includes a plasma generation nozzle 31 and a processing gas supply source 921 that employs a gas cylinder. The cooling water CW1 circulated in the temperature rise suppression means 100A cools the processing gas G supplied to the plasma generating nozzle 31, thereby suppressing the temperature of the plasma generating nozzle 31. It is configured to be able to.

  Specifically, the temperature rise suppression means 100A includes a processing gas cooler 101A that cools the processing gas G supplied to the plasma generation nozzle 31, a chiller unit 102A, a processing gas cooler 101A, and a chiller unit 102A. There are provided paths 103A, 104A of the cooling water CW1 provided between them and a processing gas temperature measuring means 105A. The temperature of the processing gas G is controlled by a gas temperature adjusting circuit 97 of the control system 90 described later.

  Here, the processing gas cooler 101A performs heat exchange Q1 between the processing gas G and the cooling water CW1 in the heat exchanging portion 106A. The heat exchanging portion 106A is cooled to the processing gas G on the outside and cooled on the inside. It is composed of a coil-type cooling water pipe in contact with the water CW1.

  The chiller unit 102A sends the cooling water CW1 to the processing gas cooler 101A, collects the cooling water CW1 warmed by the processing gas G, and returns the cooling water to a temperature that can be supplied to the processing gas cooler 101A again. CW1 is cooled, and the cooling water CW1 that circulates in the path is cooled by cooling the coiled cooling water pipe whose inner side is in contact with the cooling water CW1 by an unillustrated refrigerator by the amount of heat Q2. Yes.

  Further, the processing gas temperature measuring means 105A is composed of a thermocouple.

  The gas temperature adjusting circuit 97 adjusts the temperature of the processing gas G based on the temperature measurement result of the temperature measuring means 39 (FIG. 9) of the plasma generating nozzle 31. The control system of the plasma generator S1 described later is used. The temperature setting value is received from the 90 plume temperature control unit 96 and the temperature of the processing gas G is adjusted.

  Next, the sliding short 40, the circulator 50, the dummy load 60, and the stub tuner 70, which are incidental facilities of the plasma generation unit PU, will be described with reference to FIGS. 6 is a perspective view showing the internal structure of the sliding short 40 of the plasma generator S1 according to the first embodiment, and FIG. 7 shows the operation of the circulator 50 of the plasma generator S1 according to the first embodiment. It is a top view of plasma generation unit PU for demonstrating. FIG. 8 is a perspective side view showing an installation state of the stub tuner 70 of the plasma generator S1 according to the first embodiment.

  As shown in FIG. 6, the sliding short 40 forms a microwave standing wave pattern inside the third waveguide piece 13, and the internal conductor 32 provided in each plasma generation nozzle 31. And the state of coupling with the microwave propagated through the waveguide 10.

  The sliding short 40 is connected to the right end portion of the third waveguide piece 13 and is configured so that the standing wave pattern can be adjusted by changing the reflection position of the microwave. That is, the sliding short 40 includes a casing section 41 having a rectangular cross section similar to that of the waveguide 10, a columnar reflection block 42 housed in the casing section 41, and the casing section 41 in the left-right direction. A rectangular block 43 that slides, a moving mechanism 44 assembled to the rectangular block 43, a shaft 45, and an adjustment knob 46 that is directly connected to the reflecting block 42 via the shaft 45 are provided.

  The casing 41 is a casing structure having a rectangular cross section made of the same material as the waveguide 10, and has a hollow space 410.

  The reflection block 42 is a cylindrical body that extends in the left-right direction so that a tip surface 421 serving as a microwave reflection surface faces the waveguide space 130 of the third waveguide piece 13.

  The rectangular block 43 is a rectangular member that is integrally attached to the base end portion of the reflecting block 42, and slides in the left-right direction within the housing portion 41.

  The moving mechanism 44 is a mechanism for propelling or retreating the reflecting block 42 and the rectangular block 43 integrated therewith in the left-right direction, and the standing wave pattern is changed by adjusting the position of the tip surface 421 by the movement of the reflecting block 42. Optimized.

  The shaft 45 has a screw structure that is screwed to the moving mechanism 44. When the shaft 45 rotates, the moving mechanism 44 that is screwed to the shaft 45 is propelled or retracted in the left-right direction. .

  The adjustment knob 46 is a disk-shaped member fixed to the end of the shaft 45. By rotating the adjustment knob 46, the reflection block 42 is guided by the rectangular block 43 in the hollow space 410 in the left-right direction. It can be moved.

  As shown in FIG. 7, the circulator 50 transmits, to the microwave generator 20, reflected microwaves that are returned to the plasma generator 30 without being consumed in the microwaves propagated toward the plasma generator 30. The microwave generator 20 is prevented from being overheated by the reflected microwave by being directed to the dummy load 60 without being returned, and is composed of a waveguide-type three-port circulator with a built-in ferrite column. ing. That is, the first waveguide piece 11 is connected to the first port 51 of the circulator 50, the second waveguide piece 12 is connected to the second port 52, and the dummy load 60 is connected to the third port 53. The microwave generated from the microwave transmission antenna 22 of the microwave generator 20 travels from the first port 51 to the second waveguide piece 12 via the second port 52 as indicated by an arrow a. The reflected microwave incident from the second waveguide piece 12 side is deflected from the second port 52 toward the third port and is incident on the dummy load 60 as indicated by an arrow b.

  As shown in FIG. 7, the dummy load 60 is a radio wave absorber that absorbs reflected microwaves incident on the dummy load 60 and converts them into heat. The dummy load 60 is provided with a cooling water circulation port 61 for circulating the cooling water CW2 therein so that heat generated by converting the reflected microwave into heat is cooled by the cooling water. It has become.

  As shown in FIG. 8, the stub tuner 70 is for impedance matching between the waveguide 10 and the plasma generation nozzle 31, and is spaced from the upper surface plate 12 </ b> U of the second waveguide piece 12. And three stub tuner units 70A to 70C having the same structure arranged in series.

  Each of the stub tuner units 70A to 70C includes a stub 71 that protrudes into the waveguide space 120 of the second waveguide piece 12, an operation rod 72 that is directly connected to the stub 71, and the stub 71 that is raised and lowered in the vertical direction. It comprises a moving mechanism 73 for operating, and an outer jacket 74 that holds these mechanisms.

  Here, the protruding length of the stub 71 into the waveguide space 120 can be adjusted independently by each operation rod 72. The protruding lengths of the stubs 71 are determined by searching for a point where the power consumption by the internal conductor 32 is maximized (a point where the reflected microwave is minimized) while monitoring the microwave power. Such impedance matching is executed in conjunction with the sliding short 40 as necessary.

  Next, with reference to FIG. 9, the electrical configuration of the plasma generator S1 according to the present embodiment and the operation of the plasma generator S1 according to the present invention will be described. FIG. 9 is a block diagram showing the control system 90 of the plasma generator S1.

  As shown in FIG. 9, the control system 90 of the plasma generator S1 according to the first embodiment of the present invention includes a CPU (Central Processing Unit) and the like, and functionally includes a microwave output control unit 91 and a gas. A flow rate control unit 92, a motor control unit 93, an overall control unit 94, an operation unit 95 that gives a predetermined operation signal to the overall control unit 94, a plume temperature control unit 96 that controls the temperature of the plume P, And a gas temperature adjusting circuit 97 for adjusting the temperature of the processing gas G.

  Here, the microwave output control unit 91 performs ON / OFF control and output intensity control of the microwave output from the microwave generation device 20. The microwave output control unit 91 generates a predetermined pulse signal and uses the microwave generation device 20. Controls the operation of microwave generation.

  The gas flow rate control unit 92 controls the flow rate of the processing gas G supplied to each plasma generation nozzle 31. Specifically, the flow control valve 923 provided in the gas supply pipe 922 connecting the processing gas supply source 921 such as a gas cylinder and the plasma generation nozzle 31 is controlled to open or close or the opening is adjusted.

  The motor control unit 93 controls the operation of the drive motor 931 that rotates the transport roller 80, and controls the start and stop of transport of the workpiece W, the transport speed, and the like.

  The overall control unit 94 controls overall operation of the plasma generation device S1, and in accordance with an operation signal given from the operation unit 95, the microwave output control unit 91, the gas flow rate control unit 92, and the motor control. The operation of the unit 93 is controlled based on a predetermined sequence. That is, based on a control program given in advance, the conveyance of the workpiece W is started, the workpiece W is guided to the plasma generation unit 30, and microwave power is supplied while supplying a predetermined flow rate of the processing gas G to each plasma generation nozzle 31. The generated plasma (plume P) is generated, and the plume P is radiated to the surface of the workpiece W while it is conveyed. Thereby, the some workpiece | work W can be processed continuously.

  Further, the plume temperature control unit 96 controls the temperature of the plume P, and the set value of the temperature of the processing gas G in the gas temperature adjusting circuit 97 based on the temperature measurement result of the temperature measuring means 39 of the plasma generating nozzle 31. Send.

  The gas temperature adjusting circuit 97 receives the temperature set value from the plume temperature control unit 96 and changes the capacity Q2 of the refrigerator of the chiller unit 102A as shown in FIG. Then, by changing the capacity Q2 of the refrigerator, the heat exchange amount Q1 of the processing gas cooler 101A is also changed, and the temperature of the processing gas G is adjusted.

  In this way, in the present embodiment, the oxygen-based processing gas G such as oxygen gas or air cooled by the processing gas cooler 101A of the temperature rise suppression means 100A is supplied to the plasma generation nozzle 31. Then, the processing gas G is excited by the microwave power, and plasma (ionized gas) is generated in the vicinity of the lower end portion of the internal conductor 32. Although this plasma has an electron temperature of tens of thousands of degrees, the gas temperature is a reactive plasma that is close to the outside temperature (a plasma in which the electron temperature indicated by electrons is extremely high compared to the gas temperature indicated by neutral molecules). It is a plasma generated under normal pressure.

  Further, the plasma-ized processing gas G is emitted from the lower end edge of the nozzle body 33 as a plume P by the gas flow provided from the gas supply hole 344. This plume P contains radicals, and oxygen-based processing gas G such as oxygen gas or air is used as the processing gas G. Therefore, oxygen radicals are generated, and the organic substance is decomposed and removed. A plume P having a resist removing action or the like can be obtained. In the plasma generation unit PU according to the present embodiment, since a plurality of plasma generation nozzles 31 are arranged, it is possible to generate a line-shaped plume P extending in the left-right direction.

  In this embodiment, since the processing gas G is cooled by the processing gas cooler 101A of the temperature rise suppression means 100A, the temperature of the plume P can be prevented from becoming too high.

  According to the plasma generator S1 described above, since the temperature rise suppression means 100A suppresses the temperature rise of the plume P, the equipment for cooling the plasma generation nozzle 31 can be simplified, resulting in plasma generation. The manufacturing cost and operating cost of the apparatus can be greatly reduced. As a result, it is possible to provide a simple plasma generator with a small number of parts and less power.

  Further, since the temperature rise suppression means 100A includes the processing gas cooler 101A that cools the processing gas G supplied to the plasma generation nozzle 31, a plume that is a gas that is converted into plasma by the cooled processing gas G. As a result of being able to cool P, it is not necessary to newly provide an independent system of cooling fluid for cooling the plasma generating nozzle 31. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Furthermore, since the processing gas G is directly cooled, the response characteristics of plume temperature control are good.

  Since the plume P is cooled by the processing gas G cooled by the cooling water CW1, the amount of the cooling water CW1 is changed in the processing gas cooler 101A to easily adjust the amount of heat exchange and the temperature of the plume P. Can be adjusted.

  In particular, since the plasma generating nozzle 31 includes temperature measuring means 39 for measuring the temperature of the plume P or the plasma generating nozzle 31, the temperature of the plume P or the plasma generating nozzle 31 is monitored to control the temperature of the plasma. By adjusting to a predetermined temperature, it becomes possible to maintain a stable surface modification effect and organic matter removal effect over a long period of time regardless of the season, weather, time, and the like.

  Thus, according to the present embodiment, since the plasma generating nozzle 31 is cooled, the surface of the workpiece can be maintained at a low temperature without impairing the quality of the workpiece, such as burning or burning the workpiece. Predetermined treatments such as modification and organic substance removal can be applied.

  In addition, since the plasma generating nozzle 31 is cooled, the temperature around the nozzle portion does not become excessively high, and for example, it is possible to prevent Teflon (registered trademark), which is an insulating material of the electrode, from being softened. In addition, since it is possible to prevent changes such as dimensional changes and softening due to high heat in this way, the life of the plasma generation nozzle 31 can be extended and used for a long period of time.

  Next, a modification of the temperature rise suppression means 100A of the plasma generator S1 according to the first embodiment of the present invention will be described with reference to FIG. 10 and FIG. FIG. 10 is a conceptual diagram showing the configuration of the temperature rise suppression means 100B according to a modification of the plasma generator S1 according to the first embodiment of the present invention, and FIG. 11 shows the configuration of the first embodiment of the present invention. It is process drawing explaining control of the temperature increase suppression means 100B which concerns on the modification of the plasma generator S1 which concerns. In addition, the same code | symbol is attached | subjected about the structure similar to plasma generator S1 which concerns on 1st Embodiment, and the duplication of description shall be avoided.

  As shown in FIG. 10, the temperature rise suppression means 100B according to the modification of the plasma generator S1 according to the first embodiment includes a processing gas cooler 101B having a cooling element 102B and a heat sink 103B. The process gas cooler 101 </ b> B is configured to cool the process gas G supplied to the plasma generation nozzle 31.

  Here, the cooling element 102B of the processing gas cooler 101B employs a Peltier element in this embodiment, and the processing gas G is cooled by passing a current through the Peltier element.

  The heat sink 103B dissipates heat to the outside accompanying the cooling element 102B, and is composed of a large number of plate fin heat dissipating plates.

  And the point of control of the process gas temperature by this temperature rising suppression means 100B is as follows. That is, as shown in FIG. 11, the apparatus is turned on (step S1), gas is supplied (step S2), and after a waiting time of several seconds (step S3), the Peltier operation is started ( Step S4).

  Then, it is determined whether or not the measured gas temperature is higher than a specified value (step S5). If it is higher, the Peltier current is increased by 1 bit, and the process returns to step 3. If not, it is determined whether or not the measured gas temperature is lower than the specified value (step S7). If it is lower, the Peltier current is reduced by 1 bit and the process returns to step 3.

  Moreover, also when the gas temperature measured in step S7 is not lower than a regulation value, it returns to step 3 and the control of Peltier current is repeated again.

  Thus, according to the temperature rise suppression means 100B according to the modification of the plasma generator S1 according to the first embodiment of the present invention, the plume P is cooled by the processing gas G cooled by the cooling element 102B. By changing the heat load of the cooling element 102B in the processing gas cooler 101A, the amount of heat exchange can be easily adjusted and the temperature of the plume P can be adjusted.

  In particular, a Peltier element is provided in the processing gas cooler 101A as the cooling element 102B, and the processing gas G can be easily cooled by passing an electric current through the Peltier element. Can be made.

  Next, with reference to FIG. 12, a plasma generator S2 according to a second embodiment of the present invention will be described. FIG. 12 is a perspective view showing the configuration of the temperature rise suppression means 200A of the plasma generator S2 according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the structure similar to plasma generator S1 which concerns on 1st Embodiment, and the duplication of description shall be avoided.

  As shown in FIG. 12, the temperature rise suppression means 200A of the plasma generator S2 according to the second embodiment of the present invention includes a cooling channel 201A provided in the plasma generation nozzle 31, and the refrigerant flowing through the cooling channel 201A. Thus, the plasma generating nozzle 31 is cooled.

  Here, in the present embodiment, the processing gas G supplied to the plasma generation nozzle 31 is employed as the refrigerant flowing through the cooling channel 201A. That is, the processing gas G is configured to flow through the cooling channel 201 </ b> A and cool the plasma generating nozzle 31 before being supplied from the gas supply hole 344 and before going to the cylindrical space 332 of the nozzle body 33. .

  According to this configuration, since the plasma generating nozzle 31 is cooled by the refrigerant flowing through the cooling channel 201A and the plume P is indirectly cooled, the temperature of the plume P is maintained while the plume P is maintained in a stable state. Control can be performed gently.

  In addition, since the refrigerant is the processing gas G supplied to the plasma generation nozzle 31, it is not necessary to newly provide an independent system of cooling fluid for cooling the plasma generation nozzle 31. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Next, a modification of the temperature rise suppression means 200A of the plasma generator S2 according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a conceptual diagram showing a configuration of a temperature rise suppression means 200B according to a modification of the plasma generator S2 according to the second embodiment of the present invention, and FIG. 14 is a temperature rise according to the modification of FIG. It is explanatory drawing which shows the flow of the refrigerant | coolant in the plasma generation nozzle 31 of the suppression means 200B. FIG. 15 is an explanatory diagram showing the refrigerant flow in the entire temperature rise suppression means 200B according to the modification of FIG. In addition, the same code | symbol is attached | subjected about the structure similar to plasma generator S2 which concerns on 2nd Embodiment, and the duplication of description shall be avoided.

  As shown in FIGS. 13-15, in the temperature rise suppression means 200B which concerns on the modification of plasma generator S2 which concerns on the 2nd Embodiment of this invention, the nozzle main body 33 of the plasma generation nozzle 31 is O-ring 335A. 335B, 335C, and 335D, and four members 33A, 33B, 33C, and 33D are overlapped. Then, plasma is generated by the refrigerant flowing through the cooling channel 201B (consisting of the communicating cooling channels 202B, 203B, and 204B) formed between the four members 33A, 33B, 33C, and 33D constituting the nozzle body 33. The nozzle 31 is cooled.

  In the temperature rise suppression means 200B, the refrigerant flowing through the cooling channel 201B is a microwave absorbing medium used to absorb microwave energy in the sliding short 40 or the dummy load 60 provided in the waveguide 10. Some cooling water CW2 is adopted. That is, as shown in FIG. 15, in this embodiment, the cooling water CW2 is a dummy load 60, a plasma generation nozzle 31, and a second dummy load 60 ′ (when a dummy load is attached instead of the sliding short 40). Are circulated to recover the amount of heat Q3, Q4, Q5 related to cooling. Further, the heat amounts Q3, Q4, and Q5 related to the cooling are discharged outside the system by a refrigerator attached to the chiller unit 205B as a load Q6 of the chiller unit 205B.

  In the present embodiment, the load Q6 of the chiller unit 205B is controlled by a direct signal from the plume temperature control unit 96 based on the temperature measurement result of the temperature measuring means 39 of the plasma generating nozzle 31.

  According to this configuration, since the microwave absorbing medium used for absorbing the microwave energy in the dummy load 60 is used as the refrigerant, a separate independent system of cooling fluid for cooling the plasma generating nozzle 31 is newly provided. There is no need to provide it. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Next, a plasma generator S3 according to a third embodiment of the present invention will be described with reference to FIG. FIG. 16 is a block diagram showing the configuration of the temperature rise suppression means 300 of the plasma generator S3 according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the structure similar to plasma generator S1 which concerns on 1st Embodiment, and the duplication of description shall be avoided.

  The plasma generator S3 according to the third embodiment of the present invention includes a temperature rise suppression means 300 as shown in FIG. 16 instead of the temperature rise suppression means 100A in the plasma generator S1 according to the first embodiment. I have. That is, the temperature rise suppression means 300 of the plasma generating apparatus S3 according to the third embodiment is a plasma power changing means that can change the plasma power of the microwave generating apparatus 20 that is a microwave generating means. A temperature measuring unit 39 for measuring temperature, a microwave output control unit 91, and an overall control unit 94 are provided. When the temperature of the plasma generating nozzle 31 measured by the temperature measuring unit 39 is too high, the overall control unit 94 of the plasma power changing unit adjusts the plasma power of the microwave generator 20 via the microwave output control unit 91. The plume P can be cooled by being lowered.

  According to this configuration, the temperature measurement unit 39, the microwave output control unit 91, and the overall control unit 94, which are plasma power changing units of the temperature rise suppression unit 300, reduce the plasma power of the microwave generation unit. Thus, the plume P is cooled, so that it is not necessary to newly provide an independent system of cooling fluid for cooling the plasma generating nozzle 31. As a result, the manufacturing cost and operating cost of the plasma generator can be greatly reduced.

  Further, since the plume P is cooled by reducing the plasma power, the response characteristic of the plume temperature control is good.

  As described above, the plasma generators S1, S2, and S3 according to the embodiments of the present invention and the respective modified examples have been described. However, the present invention is not limited thereto, and for example, the following embodiments can be taken. .

  (1) For example, in the temperature rise suppression means 100A of the plasma generator S1 according to the first embodiment, the coolant that cools the processing gas G is not limited to the cooling water CW1. Various design changes can be made for the refrigerant, such as cooling the processing gas G directly with the refrigerant gas of the refrigerator.

  (2) In the temperature rise suppression means 100B according to the modification of the plasma generator S1 according to the first embodiment, the cooling element 102B is not limited to the Peltier element. Various cooling elements can be adopted as long as the cooling element can cool the processing gas G physicochemically.

  (3) Further, in the temperature rise suppression means 200A of the plasma generation device S2 according to the second embodiment, the refrigerant flowing through the cooling channel 201A provided in the plasma generation nozzle 31 is not limited to the processing gas G or the cooling water CW2. . Various refrigerants such as other low-temperature gases and liquids can be used.

  In addition, the following embodiment can be taken.

  (4) In the above embodiment, the plasma generator S1 according to the first embodiment of the present invention is a flat substrate such as a semiconductor substrate, a circuit board on which electronic components are mounted, or a flat plate shape such as a plasma display panel. Although it is configured to irradiate the workpiece W with plasma, it is not always necessary to irradiate the workpiece W with plasma, and it contributes to the chemical reaction of a specific gas. However, various design changes are possible.

  (5) Therefore, the conveying means C for conveying the workpiece W by a predetermined route is not necessarily essential.

  (6) Further, the waveguide 10 is not necessarily limited to the first waveguide piece 11 on which the microwave generator 20 is mounted, the second waveguide piece 12 to which the stub tuner 70 is assembled, and plasma. It is not necessary to be separated from the third waveguide piece 13 provided with the generation unit 30, and various design changes are possible, for example, a common waveguide can be used.

  (7) Further, the waveguide 10 is not necessarily a long tube having a rectangular cross section from aluminum, and various design changes such as a circular tube made of other nonmagnetic metal can be adopted. is there.

  (8) The microwave generator 20 is not limited to a continuously variable microwave generator that can output a microwave having a frequency of 2.45 GHz and an output energy of 1 W to 3 kW. Other microwave generation sources can also be employed.

  (9) In this embodiment, an oxygen-based processing gas G such as oxygen gas or air is supplied to the plasma generation nozzle 31. The processing gas G is an oxygen-based gas such as oxygen gas or air. It is not limited to. If an inert gas such as argon gas or nitrogen gas is used as the processing gas G, the surface cleaning and surface modification of various substrates can be performed. Further, if a compound gas containing fluorine is used, the substrate surface can be modified to a water-repellent surface, and using a compound gas containing a hydrophilic group can modify the substrate surface to a hydrophilic surface. Furthermore, if a compound gas containing a metal element is used, a metal thin film layer can be formed on the substrate.

  According to the plasma generating apparatus of the present invention, in the plasma generating apparatus capable of irradiating the plume which is a plasma gas, the equipment for cooling the plume and the plasma generating nozzle is made as simple as possible. The manufacturing cost and the operating cost can be greatly reduced.

It is a perspective view showing the whole plasma generator S1 composition concerning a 1st embodiment of the present invention. It is sectional drawing which shows the structure of the whole structure plasma generation part 30 of plasma generator S1 which concerns on 1st Embodiment. It is a side view which shows the structure of the plasma generation nozzle 31 of plasma generator S1 which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the plasma generation nozzle 31 of plasma generator S1 which concerns on 1st Embodiment. It is a conceptual diagram which shows the structure of the temperature rising suppression means 100A of plasma generator S1 which concerns on 1st Embodiment. It is a see-through | perspective perspective view which shows the internal structure of the sliding short 40 of plasma generator S1 which concerns on 1st Embodiment. It is a top view of plasma generation unit PU for demonstrating an effect | action of the circulator 50 of plasma generator S1 which concerns on 1st Embodiment. It is a see-through | perspective side view which shows the installation condition of the stub tuner 70 of plasma generator S1 which concerns on 1st Embodiment. It is a block diagram which shows the control system 90 of plasma generator S1. It is a conceptual diagram which shows the structure of the temperature rising suppression means 100B which concerns on the modification of plasma generator S1 which concerns on the 1st Embodiment of this invention. It is process drawing explaining control of the temperature increase suppression means 100B which concerns on the modification of plasma generator S1 which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the structure of the temperature rising suppression means 200A of plasma generator S2 which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram which shows the structure of the temperature increase suppression means 200B which concerns on the modification of plasma generator S2 which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the flow of the refrigerant | coolant in the plasma generation nozzle 31 of the temperature rising suppression means 200B which concerns on the modification of FIG. It is explanatory drawing which shows the flow of the refrigerant | coolant in the whole temperature rising suppression means 200B which concerns on the modification of FIG. It is a block diagram which shows the structure of the temperature rising suppression means 300 of plasma generator S3 which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

CW1 Cooling water CW2 Cooling water (microwave absorption medium)
G Process gas S1, S2, S3 Plasma generator P Plume 10 Waveguide 20 Microwave generator (microwave generator)
31 Plasma generation nozzle 39 Temperature measurement means 60 Dummy load 100A, 100B, 200A, 200B, 300 Temperature rise suppression means 101A, 101B Process gas cooler 102B Cooling element 201A, 201B Cooling channel

Claims (10)

Microwave generation means for generating a microwave, a waveguide for propagating the microwave, and a plasma provided in the waveguide for receiving the microwave and generating a predetermined processing gas based on the energy of the microwave A plasma generating nozzle that generates a plume that is gasified into plasma and emits the plume, and irradiates the plume emitted from the plasma generating nozzle,
A plasma generation apparatus comprising temperature increase suppression means for suppressing temperature increase of the plume.   The plasma generation apparatus according to claim 1, wherein the temperature rise suppression unit includes a processing gas cooler that cools the processing gas supplied to the plasma generation nozzle.   The plasma generating apparatus according to claim 2, wherein the processing gas cooler cools the processing gas supplied to the plasma generating nozzle by cooling water.   The plasma generating apparatus according to claim 2, wherein the processing gas cooler includes a cooling element, and cools the processing gas supplied to the plasma generating nozzle by the cooling element.   5. The plasma generating apparatus according to claim 4, wherein the cooling element is a Peltier element, and cools the processing gas supplied to the plasma generating nozzle by passing a current through the Peltier element. . The temperature rise suppression means includes a cooling channel provided in the plasma generation nozzle,
The plasma generating apparatus according to claim 1, wherein the plasma generating nozzle is cooled by the refrigerant flowing through the cooling channel.   The plasma generation apparatus according to claim 6, wherein the refrigerant is a processing gas supplied to the plasma generation nozzle.   The plasma generating apparatus according to claim 6, wherein the refrigerant is a microwave absorption medium used to absorb microwave energy in a dummy load provided in the waveguide. The temperature rise suppression means includes plasma power changing means capable of changing the plasma power of the microwave generating means,
2. The plasma generating apparatus according to claim 1, wherein the plasma power changing means cools the plume by reducing the plasma power of the microwave generating means.   10. The plasma generation apparatus according to claim 1, wherein the plasma generation nozzle includes temperature measuring means for measuring a temperature of the plume or the plasma generation nozzle.

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