JP4926653B2 - Plasma generator, reaction device, and light source device - Google Patents

Description

  The present invention relates to a plasma generator for generating plasma, a reaction device, and a light source device.

  Plasma is used in various fields such as the technical field of reactors and lamps. For example, in a reaction system, plasma is used in a NOx decomposition device / HC decomposition device, a dioxin decomposition device, a PFC decomposition device, a deodorization device, a virus sterilization device, an ozone generation device, and a negative ion generation device. Further, for example, in a light source system, plasma is used in a plasma lamp (fluorescent lamp, neon tube, etc.), a light source for an etching apparatus, a light source for a resist exposure apparatus, and a plasma display.

  As a method for generating plasma, a method using electric discharge is known (for example, Patent Documents 1 to 3). That is, a method for generating plasma from a gas in a discharge space by applying a voltage to an electrode arranged in or around the discharge space where the gas exists to cause discharge in the discharge space is known. It has been.

In Patent Document 1, a discharge space surrounded by these plate-like members is formed by combining a substrate, two side plates orthogonal to the substrate, and a front plate facing the substrate. In Patent Document 2, a discharge space is formed between the dielectrics by disposing a spacer between the two dielectrics.
JP 2006-179202 A JP 2003-286829 A Japanese Patent Laid-Open No. 2005-220019

  In the techniques of cited references 1 and 2, a discharge space is formed by combining a plurality of members. When plasma discharge is performed, heat is generated, so that each member expands according to its own specific thermal expansion. Therefore, the thermal stress due to the difference in thermal expansion concentrates on the interface portion between the members, which may cause the member to be damaged. In the case where a plurality of discharge spaces are provided, a plurality of combinations of members constituting each discharge space are arranged, which increases the size of the apparatus and increases the number of parts.

  An object of the present invention is to provide a plasma generator, a reaction device, and a light source device that can improve the durability of a member that forms a discharge space.

  The plasma generator of the present invention includes a dielectric that has a discharge space and is integrally formed, and an electrode that is fixed to the dielectric and can generate plasma in the discharge space.

  Preferably, the electrodes include a pair of electrodes that are arranged opposite to each other with the discharge space interposed therebetween and are embedded in the dielectric.

  Preferably, a plurality of the discharge spaces are provided along a predetermined direction, and the electrodes include a plurality of electrodes arranged alternately with the plurality of discharge spaces in the predetermined direction.

  Preferably, every other electrode is connected to each other.

  Preferably, on the surface exposed to the discharge space, the area ratio of the crystal phase is higher than the area ratio of the glass phase.

  Preferably, in the dielectric, at least a main component of a portion exposed to the discharge space is cordierite ceramics.

  Preferably, the dielectric is provided with a heater.

  Preferably, a temperature detecting element is provided in the dielectric.

  Preferably, a conductive path embedded in the dielectric, having one end connected to the electrode and the other end exposed to the outside of the dielectric or connected to a terminal exposed to the outside of the dielectric.

  Preferably, the dielectric is formed by firing a plurality of laminated dielectric layers, and the discharge space includes gaps between the plurality of dielectric layers formed by providing holes in the dielectric layer. It is configured to include.

  The reaction apparatus of the present invention includes a plasma generator according to any one of the above, a supply unit capable of supplying a fluid to be processed to the discharge space, and a plasma generated in the discharge space to chemistry the fluid to be processed. An electrode control unit capable of applying a voltage to the electrode so as to be changed.

  A light source device according to the present invention includes a casing that includes the plasma generator according to any one of the above, and a light-transmitting portion that accommodates the plasma generator and can emit light generated by plasma generation in the discharge space. It comprises.

  Preferably, a reflection part capable of reflecting light emitted by plasma generation in the discharge space is provided in the casing.

  Preferably, the dielectric has a reflectance of 50% or more of light emitted by plasma generation in the discharge space.

  ADVANTAGE OF THE INVENTION According to this invention, durability of the member which forms discharge space can be improved.

(First embodiment)
FIG. 1 is a perspective view showing the appearance of the plasma generator 1 according to the first embodiment of the present invention, and FIG. 1A is a view as seen from the first surface S1 side of the plasma generator 1. FIG.1 (b) is the figure seen from the 2nd surface S2 side used as the back surface of 1st surface S1.

  The plasma generator 1 includes a base 3 formed in a substantially rectangular parallelepiped shape. The base 3 includes a first surface S1 and a second surface S2 that face each other, and a third surface S3 and a fourth surface S4 that are orthogonal to the first surface S1 and the second surface S2 and face each other. The fifth surface S5 and the sixth surface S6 are orthogonal to the first to fourth surfaces S1 to S4 and face each other.

  The base 3 is integrally formed. That is, the base 3 is entirely formed of the same material and is formed as a single member and has no interface. In other words, the base body 3 is not a plurality of members fixed to each other by an adhesive, a screw, or an engaging portion. The base 3 is made of a dielectric (nonconductor). For example, the base 3 is made of ceramic.

  The substrate 3 is formed with first to third discharge spaces 5A to 5C (hereinafter simply referred to as “discharge spaces 5”, which are sometimes not distinguished from each other) in which discharge is performed to generate plasma. . FIG. 1 illustrates a case where three discharge spaces 5 are provided.

  The discharge space 5 is formed in a hole shape that opens in the first surface S1 and the second surface S2. In other words, the discharge space 5 is a space that is surrounded on all four sides (directions facing the third to sixth surfaces S3 to S6) and is open in two directions. The discharge space 5 is formed in a thin rectangular parallelepiped shape, for example. In the following description, the facing direction of the first surface S1 and the second surface S2 is the length direction or the opening direction of the discharge space 5, and the facing direction of the third surface S3 and the fourth surface S4 is the discharge space 5. The width direction and the opposing direction of the fifth surface S5 and the sixth surface S6 may be referred to as the thickness direction of the discharge space 5. The first to third discharge spaces 5A to 5C are formed in the same shape.

  The first to third discharge spaces 5A to 5C are arranged in a line in a predetermined direction. Specifically, the first to third discharge spaces 5A to 5C are arranged in a row in the thickness direction and arranged in parallel to the opening direction. The intervals between the first to third discharge spaces 5A to 5C are the same. That is, the interval between the first discharge space 5A and the second discharge space 5B is equal to the interval between the second discharge space 5B and the third discharge space 5C.

  Various members such as terminals are exposed on the surface of the base 3. Specifically, it is as follows.

  The third surface S3 exposes a first electrode terminal 7A for applying a voltage to an electrode 15 (see FIG. 2) described later, and the fourth surface S4 is used to apply a voltage to the electrode 15. The second electrode terminal 7B (hereinafter simply referred to as “electrode terminal 7”, which may not be distinguished from each other) is exposed. The electrode terminal 7 is made of, for example, a flat metal and is disposed along the third surface S3 and the fourth surface S4. The electrode terminal 7 is disposed, for example, approximately at the center of the third surface S3 or the fourth surface S4.

  An inflow connection tube 9A for allowing the cooling medium to flow into the base 3 projects from the third surface S3, and an outflow connection tube for causing the cooling medium to flow out from the base 3 from the fourth surface S4. 9B (hereinafter simply referred to as “connection pipe 9”, which may not be distinguished from each other) protrudes. The connecting pipe 9 is formed integrally with the base 3. The cooling medium is water, for example.

  The inflow connecting pipe 9A can be connected to a supply flow pipe 50A provided in a device different from the plasma generator 1 and capable of supplying a cooling medium, and the outflow connecting pipe 9B is connected to the plasma generator 1 Is a discharge flow pipe 50B (hereinafter simply referred to as "flow pipe 50") provided in another device and capable of discharging the cooling medium, and the supply flow pipe 50A and the discharge flow pipe 50B may not be distinguished from each other. )). The connecting pipe 9 is connected to the flow pipe 50 by being fitted and inserted into the flow pipe 50, for example. The cross-sectional shape of the connecting tube 9 may be an appropriate shape, for example, a circular shape or a rectangular shape. FIG. 1 illustrates the case of a circular cross section.

  On the third surface S3, a first sensor terminal 11A and a second sensor terminal 11B (hereinafter simply referred to as “sensor terminal 11”) for outputting an electrical signal from a temperature detection element 19 (see FIG. 2) described later. "It may not distinguish between these." The sensor terminal 11 is made of, for example, a flat metal, and is disposed along the third surface S3 or the fourth surface S4.

  On the third surface S3, a first heater terminal 13A and a second heater terminal 13B (hereinafter simply referred to as “heater terminal 13”) for supplying power to a heater 21 (see FIG. 2) described later. , These may not be distinguished.) Are exposed. The heater terminal 13 is made of, for example, a flat metal and is disposed along the third surface S3 and the fourth surface S4.

  FIG. 2 is a view showing a cross section taken along line II-II in FIG.

  Inside the base 3, the first electrode 15 </ b> A, the second electrode 15 </ b> B, the third electrode 15 </ b> C, and the fourth electrode 15 </ b> D (hereinafter simply referred to as “electrode 15”) for performing discharge in the discharge space 5 are not distinguished. ), A flow path 17 for flowing a cooling medium inside the base body 3, a temperature detection element 19 for detecting the temperature inside the base body 3, and a heater 21 for heating the base body 3 are provided. It has been.

  The electrode 15 is constituted by a so-called capacitor-type electrode. That is, the electrode 15 is formed in a substantially flat plate shape and is disposed so as to face the discharge space 5. Then, due to the potential difference between the two electrodes 15 arranged opposite to each other across the discharge space 5, discharge is performed in the sandwiched discharge space 5, and plasma is generated. The discharge is, for example, a so-called high frequency discharge that is performed by applying an AC voltage having a relatively high frequency to the pair of electrodes 15. The frequency of the applied AC voltage is, for example, 10 MHz to 100 MHz. The electrode 15 is made of a metal such as tungsten, molybdenum, platinum, gold, palladium, silver, or copper.

  The plurality of electrodes 15 are alternately arranged with respect to the plurality of discharge spaces 5 in the arrangement direction of the plurality of discharge spaces 5. Therefore, the electrode 15 sandwiched between the two discharge spaces 5 functions as an electrode that performs discharge in one discharge space 5 and also functions as an electrode that performs discharge in the other discharge space 5.

  Specifically, the first electrode 15A, the first discharge space 5A, the second electrode 15B, the second discharge space 5B, the third electrode 15C, the third discharge space 5C, and the fourth electrode 15C are arranged in this order. Then, in the first discharge space 5A, discharge is performed by the first electrode 15A and the second electrode 15B, and in the second discharge space 5B, discharge is performed by the second electrode 15B and the third electrode 15C, and the third discharge space. In 5C, discharge is performed by the third electrode 15C and the fourth electrode 15D. The electrode 15 sandwiched between the two discharge spaces 5 is disposed at the center of the two discharge spaces 5, for example. The plurality of electrodes 15 are arranged at regular intervals, for example.

  The plurality of electrodes 15 are connected to each other in the arrangement direction to constitute two sets of electrode groups. That is, the first electrode 15A and the third electrode 15C are connected to each other to form the first electrode group 23A, and the second electrode 15B and the fourth electrode 15D are connected to each other to connect the second electrode group 23B (hereinafter, both Are simply referred to as “electrode group 23”). The first electrode group 23A is connected to the first electrode terminal 7A, and the second electrode group 23B is connected to the second electrode terminal 7B. Therefore, by applying an AC voltage to the first electrode terminal 7A and the second electrode terminal 7B, a voltage is applied between the pair of electrodes 15 facing each other.

  In each electrode group 23, the electrode conductive path 25 that connects the electrodes 15 and connects each electrode 15 to the electrode terminal 7 is formed, for example, in a circular cross section and extends in a direction orthogonal to the electrode 15. 15 includes an orthogonal portion 25 a that connects the 15 and a horizontal portion 25 b that extends from the orthogonal portion 25 a in a direction parallel to the electrode 15 and is connected to the electrode terminal 7. The electrode terminal 7 may be omitted and the horizontal portion 25b may be exposed from the base body 3.

  The electrode 15 is embedded in the base 3. That is, the mutually opposing surfaces, the back surface and the side surfaces thereof are covered with the substrate 3. In the high-frequency discharge, the polarity of the electric field is reversed before the electrons from one electrode 15 toward the other electrode 15 collide with the dielectric (substrate 3) covering the other electrode 15. That is, the discharge is maintained even when the electrode 15 is covered with a dielectric.

  The flow path 17 extends from the inflow connecting pipe 9A to the outflow connecting pipe 9B. The flow path 17 has, for example, a plurality of electrode cooling portions 17 a that extend along the electrodes 15 corresponding to the plurality of electrodes 15. The electrode cooling unit 17a extends, for example, along the surface of the electrode 15 on the side where the discharge space 5 is disposed. In other words, the electrode cooling part 17 a extends between the electrode 15 and the discharge space 5. The electrode cooling part 17a extends meandering over substantially the entire surface of the electrode 15, for example. The plurality of electrode cooling parts 17a are communicated with each other at a discharge part 5 and a communication part 17b (see FIG. 3) extending in a direction orthogonal to the electrode 15 on the outer peripheral side of the electrode 15. The flow path 17 extends, for example, from the inflow connecting pipe 9A to the outflow connecting pipe 9B with a constant cross-sectional area.

  The flow path 17 is not limited to a structure in which a fluid flows directly into a groove or a hole formed in the base 3, and may be formed by embedding a tubular member in the base 3.

  The temperature detection element 19 is configured by a resistor, for example. The temperature detection element 19 is connected to the sensor terminal 11 via a sensor conductive path 27 embedded in the base 3. The temperature around the temperature detection element 19 can be detected by applying a voltage to the sensor terminal 11 and measuring the change in resistance value according to the temperature change of the temperature detection element 19. The temperature detection element 19 is embedded in an appropriate position of the base 3, for example, between the electrode 15 and the discharge space 5.

  The heater 21 is, for example, a heating wire 21a (not shown) (not shown in FIG. 2). The rectangle indicating the heater 21 in FIG. 2 conceptually indicates the arrangement range of the heating wire 21a. It is configured to include. The heating wire 21 a is connected to the heater terminal 13 through a heater conductive path 29 embedded in the base 3. Therefore, the periphery of the heater 21 can be heated by applying a voltage to the heater terminal 13. The heating wire 21 a is embedded in an appropriate shape at an appropriate position of the base 3. For example, the heating wire 21a is embedded between the electrode 15 near the center and the discharge space 5, and extends in a plane along the electrode 15 by meandering or spiraling.

  The base 3 of the plasma generator 1 having the above configuration is formed, for example, by laminating and firing a dielectric layer (insulating layer) such as a ceramic green sheet. That is, it is formed of a laminate of dielectric layers. For example, the conductive material such as the electrode 15, the temperature detection element 19, the heating wire 21 a, the electrode conductive path 25, the sensor conductive path 27, and the heater conductive path 29 has a conductive paste disposed on a dielectric layer before firing. By being fired together with the dielectric layer formed, it is embedded and fixed in the substrate 3. The discharge space 5 and the flow path 17 are formed by providing a hole in the dielectric layer before firing.

  For example, alumina ceramics, zirconia ceramics, cordierite ceramics, silicon nitride ceramics, aluminum nitride ceramics, silicon carbide ceramics, yttria ceramics, sapphire ceramics, etc. are used as the dielectric constituting the substrate 3.

  From the viewpoint of radiating the heat generated by the discharge to the outside, it is preferable to use silicon nitride ceramics or aluminum nitride ceramics having high thermal conductivity. Further, from the viewpoint of preventing the base 3 from being damaged, it is preferable to use high-strength silicon carbide ceramics.

  Preferably, the dielectric constituting the substrate 3 should have a crystal phase area ratio higher than the glass phase area ratio on the surface exposed to the discharge space 5. With this configuration, the substrate 3 can be effectively prevented from being etched by the plasma generated in the discharge space 5. That is, the surface of the dielectric exposed to the discharge space 5 has resistance to etching by plasma by increasing the ratio of the crystal phase bonded by the covalent bond having a very high bonding force.

  More preferably, the area ratio of the crystal phase is 90 to 100% of the area ratio of the glass phase on the surface exposed to the discharge space 5 of the dielectric constituting the substrate 3. With this configuration, it is possible to improve the durability of the surface exposed to the discharge space 5 against plasma, and it is possible to effectively prevent thermal stress from being generated by reducing the coefficient of thermal expansion of the substrate 3.

  In order to increase the proportion of such a crystal phase, cordierite ceramics, alumina ceramics, and zirconia ceramics are used as dielectric materials, and the content and firing conditions of additives such as sintering aids as raw materials are adjusted. As a result, a desired one can be obtained.

  More preferably, in the dielectric, at least a main component of a portion exposed to the discharge space 5 is cordierite ceramic. Cordierite ceramics are crystalline ceramics and hardly form a glass phase, so that they are very resistant to etching by plasma. Further, cordierite has a linear thermal expansion coefficient of about 2 ppm / ° C., and can reduce the thermal expansion of the substrate 3 due to the heat at the time of plasma generation, thereby effectively preventing the occurrence of stress.

  As for the ratio of such a crystal phase, the area ratio can be obtained by surface state observation by SEM or the like. The crystallinity can be determined by using X-ray diffraction.

  In addition, in this application, the hole part of a dielectric layer shall include what does not penetrate a dielectric layer (recessed part), and what penetrates a dielectric layer (hole part). Further, the hole portion includes a hole portion having an equal aspect ratio (for example, a circle or a rectangle) in a plan view in the depth direction and a long shape (hereinafter also referred to as a “groove portion”). The groove portion does not penetrate the dielectric layer (hereinafter, sometimes referred to as “concave groove”, which is a kind of concave portion), and the groove portion (hereinafter, referred to as “slit”, which is a kind of hole portion). .)) And both.

  FIG. 3 is a conceptual diagram illustrating that the plasma generator 1 is formed as described above, taking a part of the plasma generator 1 as an example. FIG. 3 illustrates only the first portion 3a (see FIG. 2) on the fifth surface S5 side of the base body 3. Further, in FIG. 3, similarly to FIG. 2, the base body 3 is shown cut along the line II-II in FIG. 1. In FIG. 3, the flow path 17 is shown larger than that in FIG. For this reason, the shape and position of the channel 17 and the like are slightly different from those in FIG.

  As shown in FIG. 3, the first portion 3 a of the base 3 is referred to as six first dielectric layers 31 </ b> A to 31 </ b> F (hereinafter simply referred to as “dielectric layers 31”), which may not be distinguished. ). The number of dielectric layers 31 is six as an example, and the number of dielectric layers 31 may be set as appropriate. Further, in the present application, the two dielectric layers such as the fifth dielectric layer 31E will be described as the same dielectric layer if the stacking positions are the same.

  The plurality of dielectric layers 31 have, for example, the same width, thickness, and shape as each other. Note that the plurality of dielectric layers 31 may not have the same width, thickness, and shape. However, if the plurality of dielectric layers 31 have the same width, thickness, and shape, the manufacturing cost is reduced.

The dielectric layer 31 is, for example, alumina ceramics, and is formed including, for example, a glass component made of SiO ₂ , Al ₂ O ₃ , MgO, ZnO, B ₂ O _3, and alumina particles. The laminated dielectric layer 31 is baked in a reducing atmosphere of 900 ° C. to 1700 ° C., for example.

  The discharge space 5 includes gaps between the plurality of dielectric layers 31 formed by forming holes in at least one of the plurality of dielectric layers 31. For example, the discharge space 5A includes a recess 33D provided on the surface of the fourth dielectric layer 31D on the fifth dielectric layer 31E side, a hole 34 provided in the fifth dielectric layer 31E, and the sixth dielectric layer 31F. A recess 33F provided on the surface on the fifth dielectric layer 31E side is formed by a gap between the fourth dielectric layer 31D and the sixth dielectric layer 31F formed to communicate with each other. In the present application, like the hole 34, the gap (hole 34) between the two divided layers 31E-1 and 31E-2 constituting one dielectric layer (fifth dielectric layer 31E) is also one. It shall be contained in the hole provided in the dielectric layer.

  Note that the discharge space 5 may be configured only by the holes formed in one or more dielectric layers, for example, the discharge space 5A may be configured by only the holes 34 without the recess 33D and the recess 33F. The dielectric layer 31E is a dielectric layer having a recess on the surface on the fourth dielectric layer 31D side, and the discharge space 5 is configured by connecting the recess of the fifth dielectric layer 31E and the recess 33D of the fourth dielectric layer 31D. The discharge space 5 may be composed of only two recesses, or the fifth dielectric layer 31E may be a dielectric layer having no recesses or holes, and the discharge space 5 may be composed of only the recesses 33D of the fourth dielectric layer 31D. The discharge space 5 may be constituted by only one concave portion. The discharge space 5 may be configured to include a portion other than the gap between the dielectric layers 31 such as communication between the gap between the dielectric layers 31 and a hole provided in the lowermost layer or the uppermost layer of the dielectric layer 31. .

  The electrode 15 is formed, for example, by firing a conductive paste laminated on the dielectric layer 31 together with the plurality of laminated dielectric layers 31. For example, the electrode 15A is formed by placing and baking a conductive paste to be the electrode 15A between the second dielectric layer 31B and the third dielectric layer 31C. When the thickness of the electrode 15A is large, as illustrated in FIG. 3, the concave portion 33 for arranging the conductive paste to be the electrode 15A is provided with at least one of the second dielectric layer 31B and the third dielectric layer 31C. You may form in the 31 opposing surface. Alternatively, a hole for arranging the conductive paste to be the electrode 15A is provided in the second dielectric layer 31B, and the conductive paste to be the electrode 15A is arranged between the first dielectric layer 31A and the third dielectric layer 31C. A conductive paste to be the electrode 15 </ b> A may be disposed in a hole provided in one or more dielectric layers 31.

  The electrode conductive path 25, the sensor conductive path 27, and the heater conductive path 29 are laminated by filling the conductive layer in the hole (via hole) formed in the dielectric layer 31 at a portion that penetrates the dielectric layer 31. It is formed by firing together with a plurality of dielectric layers 31. That is, it is formed by a via conductor. Further, these conductive paths are formed by a portion along the dielectric layer 31 being laminated with a conductive paste on the dielectric layer 31 and firing together with the plurality of laminated dielectric layers 31. When laminating the conductive paste on the dielectric layer 31, a groove or the like for arranging the conductive paste may be provided in the dielectric layer 31. In FIG. 3, the conductive paste is arranged in the hole 37 </ b> C formed in the third dielectric layer 31 </ b> C and the fourth dielectric layer 31 </ b> D filled with the conductive paste that becomes the orthogonal portion 25 a of the electrode conductive path 25. The hole portion 37D, the hole portion 37E formed in the fifth dielectric layer 31E, and the hole portion 37F formed in the fourth dielectric layer 31F are illustrated. The via conductors filled in the hole portions 37C to 37F are baked and connected to each other to form one conductor.

  Similarly to the electrode 15, the electrode conductive path 25, the sensor conductive path 27, and the heater conductive path 29, the resistor constituting the temperature detection element 19 and the heating wire 21 a constituting the heater 21 are also the dielectric layer 31 before firing. It is formed by disposing a conductive paste on. Moreover, the hole part for arrange | positioning the electrically conductive paste which comprises these is suitably provided in the dielectric layer 31 before baking as needed.

  The electrode terminal 7, the sensor terminal 11, and the heater terminal 13 may be configured by attaching a metal plate to the fired base 3, or the above-described electrode conductive path 25, sensor conductive path 27, and heater. Similarly to the conductive path 29 and the like, the conductive paste may be disposed on the side surface of the dielectric layer 31 before firing, and the dielectric layer 31 may be fired. Moreover, the hole part for arrange | positioning the electrically conductive paste which comprises these may be suitably provided in the dielectric layer 31 before baking as needed.

  The flow path 17 is formed including gaps between the plurality of dielectric layers 31 formed by forming holes in at least one of the plurality of dielectric layers 31. For example, the electrode cooling unit 17a has a gap between the third dielectric layer 31C and the fourth dielectric layer 31D formed by forming a concave groove 39C on the surface of the third dielectric layer 31C on the fourth dielectric layer 31D side. It is comprised by. In addition, for example, a part of the communication part 17b includes a hole part 41D formed in the fourth dielectric layer 31D, a hole part 41E formed in the fifth dielectric layer 31E, and a hole part 41F formed in the sixth dielectric layer 31F. Are formed by a gap between the third dielectric layer 31C and the dielectric layer 31 below the sixth dielectric layer 31F formed by communicating with each other.

  A groove is formed at the same position as the groove 39C on the surface of the third dielectric layer 31C side on the fourth dielectric layer 31D side, and the electrode cooling part 17a is formed by the groove and the groove 39C. The opposing cooling grooves may be connected to form the electrode cooling portion 17a, or a slit may be formed in one or more dielectric layers 31 like the fifth dielectric layer 31E that forms the discharge space 5A. The electrode cooling unit 17a may be configured by sandwiching the dielectric layer 31 with another dielectric layer. The flow path 17 may be configured to include a portion other than the gap between the dielectric layers 31 such as communication between the gap between the dielectric layers 31 and a hole provided in the lowermost layer or the uppermost layer of the dielectric layer 31. .

  The inflow connecting pipe 9A is made of the same material as that of the dielectric layer 31, for example. Then, it is integrally formed with the substrate 3 by firing together with the dielectric layer 31 in a state of being in contact with the side of the laminated dielectric layer 31 before firing at a predetermined pressure. The method of forming the outflow connection pipe 9B is the same.

  According to the first embodiment described above, the plasma generator 1 has the discharge space 5, and is integrally formed with the base body 3 (dielectric material) and the base body 3, and is discharged into the discharge space 5 by discharge. And the electrode 15 capable of generating plasma in the electrical path from the electrode 15 to the discharge space 5 and there is no interface in the part forming the discharge space 5, and there is no interface between the members at the interface part between the members. Concentration of thermal stress due to the difference in thermal expansion is suppressed, and durability is improved.

  In particular, when the plasma generator 1 is provided with a pair of electrodes that are opposed to each other across the discharge space 5 as the electrodes 15 and are embedded in the base 3, there is no interface between the electrodes. Further, the effect of improving durability by suppressing thermal stress concentration is further expected.

  A plurality of discharge spaces 5 are provided along a predetermined direction, and the plasma generator 1 includes a plurality of electrodes 15 arranged alternately with the plurality of discharge spaces 5 in the predetermined direction as the electrodes 15. One electrode 15 sandwiched between two discharge spaces 5 functions as an electrode that performs discharge in one discharge space 5 and also functions as an electrode that performs discharge in the other discharge space 5, thereby reducing the size of the plasma generator 1. It is possible to generate a large amount of plasma in the plurality of discharge spaces 5 while being converted.

  Since the plurality of electrodes 15 are alternately connected to each other, the electrode terminals 7 for applying a voltage to the plurality of electrodes 15 can be shared by the plurality of electrodes 15. The number of points can be reduced.

  Since the substrate 21 is provided with the heater 21, the plasma generator 1 can be quickly raised to a temperature suitable for plasma generation at the start of discharge. In addition, since the heater 21 is provided in the base 3 that forms the discharge space 5 and holds the electrode 15, the base 3 is highly functionalized and the plasma generator 1 as a whole can be miniaturized. .

  Since the temperature detection element 19 is provided on the base 3, the temperature of the plasma generator 1 is detected, and the temperature of the plasma generator 1 is controlled to a temperature suitable for plasma generation, or an abnormality of the plasma generator 1 is detected. Can be detected. Moreover, since the temperature detecting element 19 is provided in the base 3 that forms the discharge space 5 and holds the electrode 15, the function of the base 3 is enhanced, and the plasma generator 1 as a whole can be downsized. Figured.

  The substrate 3 is formed by firing a plurality of laminated dielectric layers 31, and the discharge space 5 is a gap between the plurality of dielectric layers 31 formed by providing a hole in at least one dielectric layer 31. Therefore, it is easy to form the substrate 3 having the discharge space 5. Further, by arranging the conductors such as the electrodes 15 and the electrode conductive paths 25 on the dielectric layer 31 before lamination, it is possible to facilitate the arrangement and fixing of these conductors to the base 3.

  The plasma generator 1 includes an electrode 15 for generating plasma in the discharge space 5 by discharge, a flow path 17 to which the electrode 15 is fixed, and extending along the electrode 15. 3, the flow path 17 is provided in the base 3 that holds the electrode 15 to enhance the functionality of the base 3, and the base 3 is integrally formed to reduce the number of parts and generate plasma. The entire body 1 can be reduced in size.

  Since the discharge space 5 is formed in the base 3, further enhancement of the function of the base 3 is achieved. In addition, as described above, there is no interface in the electrical path from the electrode 15 to the discharge space 5 or the portion where the discharge space 5 is formed, the concentration of thermal stress is suppressed, and the durability is improved.

  Since the electrode 15 is embedded in the base body 3 and the flow path 17 is disposed between the discharge space 5 and the electrode 15, the discharge space 5 side that tends to become a high temperature generally around the electrode 15. Can be efficiently cooled.

  When the electrode 15 includes a pair of electrodes 15 disposed opposite to each other across the discharge space 5 and embedded in the base 3, and the flow path 17 is provided along both the pair of electrodes 15, As described above, there is no interface between the electrodes, and it is expected that durability is improved by suppressing thermal stress concentration, and each electrode 15 can be sufficiently cooled.

  A plurality of discharge spaces 5 are provided along a predetermined direction, and the electrodes 15 include a plurality of electrodes 15 arranged alternately with the plurality of discharge spaces 5 in the predetermined direction. As described above, one electrode 15 can be used for the discharge of the two discharge spaces 5, and a large amount of plasma is generated in the plurality of discharge spaces 5 while miniaturizing the plasma generator 1. In addition to the fact that the cooling effect of the electrode 15 can be maintained, the number of the flow paths 17 is reduced as the number of the electrodes 15 is reduced, and the plasma generator 1 can be further reduced in size.

  The base body 3 is provided with an inflow connection tube 9A that can be connected to a supply flow tube 50A that can supply a cooling medium and an outflow connection tube 9B that can be connected to an exhaust flow tube 50B that can discharge a cooling medium. Therefore, the function of the substrate 3 is further enhanced, and the plasma generator 1 or the apparatus to which the plasma generator 1 is attached can be reduced in size.

  Since the connecting pipe 9 is formed integrally with the base body 3, an increase in the number of parts is suppressed, and downsizing of the entire plasma generator 1 is facilitated.

  The base 3 is formed by firing a plurality of laminated dielectric layers 31, and the flow path 17 includes gaps between the plurality of dielectric layers 31 formed by holes provided in at least one dielectric layer 31. Therefore, it is possible to easily form a flow path having an arbitrary shape by providing a hole having an appropriate shape in each dielectric layer 31.

  Since the electrode 15 is formed of a conductor fixed to the base 3 by being fired together with the laminated dielectric layer 31, it is easy to fix the electrode 15 at an arbitrary position of the base 3. For example, it is easy to embed the electrode 15 in the base 3.

(Second Embodiment)
FIG. 4 is a conceptual diagram showing a structural configuration of the reaction apparatus 100 according to the second embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and description is abbreviate | omitted.

  The reaction apparatus 100 includes the plasma generator 1 of the first embodiment, and is configured as an apparatus that processes and discharges a fluid to be processed by the plasma generator 1. The fluid to be treated is, for example, exhaust gas of an internal combustion engine of an automobile, and NOx is decomposed by a chemical change in the discharge space 5. Further, for example, the fluid to be treated is chlorofluorocarbon used as a cooling medium in a refrigerator or an air conditioner, and chlorofluorocarbon is decomposed by a chemical change in the discharge space 5. In the following description, a portion of the reaction apparatus 100 other than the plasma generator 1 may be referred to as a reaction apparatus main body 101.

  The reactor main body 101 is processed by a fluid source 103 that supplies a fluid to be processed, a supply pipe 105 (an example of a supply unit) that guides the fluid to be processed from the fluid source 103 to the plasma generator 1, and the plasma generator 1. A discharge pipe 107 for discharging the treated fluid, a treated fluid pump 109 for controlling the flow of the treated fluid, a coolant source 111 for supplying a cooling medium, and cooling from the coolant source 111 to the plasma generator 1 A supply flow pipe 50A (an example of a cooling unit) that guides the medium, a discharge flow pipe 50B that guides the cooling medium from the plasma generator 1 to the refrigerant source 111, and a cooling medium pump 113 that controls the flow of the cooling medium. (An example of a cooling unit).

  The fluid source 103 generates a fluid to be processed such as an internal combustion engine of an automobile that discharges exhaust gas as the fluid to be processed. Alternatively, the fluid source 103 holds a fluid to be processed such as a tank that holds a cooling medium of a used refrigerator or an air conditioner.

  One end side of the supply tube 105 communicates with a space for generating or holding the fluid to be processed of the fluid source 103, and the other end side communicates with the discharge space 5 of the plasma generator 1. The plasma generator 1 side of the supply tube 105 corresponds to the number of the discharge spaces 5, and is referred to as a first branch part 105aA, a second branch part 105aB, and a third branch part 105aC (hereinafter simply referred to as “branch part 105a”. The first branch portion 105aA to the third branch portion 105aC communicate with the first discharge space 5A to the third discharge space 5C, respectively.

  One end side of the discharge tube 107 communicates with the discharge space 5 of the plasma generator 1 from the side opposite to the supply tube 105, and the other end side is opened to the atmosphere, or holds or treats the processed fluid after processing. It communicates with a space (not shown) for performing another process on the fluid to be processed later. The plasma generator 1 side of the discharge tube 107 corresponds to the number of discharge spaces 5, and is referred to as a first branch portion 107aA, a second branch portion 107aB, and a third branch portion 107aC (hereinafter simply referred to as “branch portion 107a”. The first branch portion 107aA to the third branch portion 107aC communicate with the first discharge space 5A to the third discharge space 5C, respectively. Note that the discharge pipe 107 may be omitted. For example, the treated fluid after treatment may be directly discharged from the discharge space 5 to the atmosphere.

  The supply pipe 105 and the discharge pipe 107 are formed of an appropriate material such as metal or resin. The supply pipe 105 and the discharge pipe 107 may or may not have flexibility. The connection between the branch part 105a and the branch part 107a and the discharge space 5 is made, for example, by bringing the end part of the branch part 105a or the branch part 107a into contact with the second surface S2 or the first surface S1 of the base 3. This is performed by fixing the branch portion 105a or the branch portion 107a and the base 3 with an appropriate fixing member such as an adhesive or a screwing member. The branch portion 105a and the branch portion 107a are fitted and inserted into the discharge space 5, or a protruding annular portion is formed integrally with the base 3 at the end of the discharge space 5 as in the connecting tube 9, and the protrusion It may be performed by fitting and inserting the portion into the branching portion 105a or the branching portion 107a.

  The fluid pump 109 to be processed is provided in at least one of the supply pipe 105 and the discharge pipe 107. FIG. 4 illustrates a case where the supply pipe 105 is provided. When the fluid to be processed is caused to flow by the power of the fluid source 103, such as when the fluid source 103 is an internal combustion engine, the pump for fluid to be processed 109 may be omitted. Further, the pump 109 for fluid to be processed can be provided in the plasma generator 1. The fluid pump 109 to be processed may be constituted by an appropriate pump such as a rotary pump or a reciprocating pump.

  The refrigerant source 111 includes, for example, a heat exchanger, and lowers the temperature of the cooling medium from the discharge flow pipe 50B by the heat exchanger and supplies it to the supply flow pipe 50A. Note that the coolant source 111 need only be able to supply a cooling medium, and may not receive the cooling medium from the discharge flow pipe 50B and circulate the cooling medium. That is, the cooling medium from the discharge flow pipe 50 </ b> B may be discharged to a location different from the refrigerant source 111. For example, when tap water is used as the cooling medium, the water from the discharge flow pipe 50 </ b> B may be discharged to a location different from the water source as the refrigerant source 111. Conversely, when the cooling medium is circulated, the refrigerant source 111 may be omitted.

  One end of the supply flow pipe 50A communicates with the refrigerant source 111, and the other end communicates with the flow path 17 of the plasma generator 1 via the inflow connection pipe 9A as described above. As described above, one end of the discharge flow pipe 50B communicates with the flow path 17 of the plasma generator 1 via the outflow connection pipe 9B, and the other end communicates with the refrigerant source 111. The flow tube 50 is formed of an appropriate material such as metal or resin. The flow tube 50 may or may not have flexibility.

  The cooling medium pump 113 is provided in at least one of the supply flow pipe 50A and the discharge flow pipe 50B. FIG. 4 illustrates a case where the supply flow pipe 50A is provided. Note that the cooling medium pump 113 is omitted when the coolant source 111 is a tank in a high position and power for flowing the cooling medium appropriately can be obtained, for example, the cooling medium can flow by gravity. Also good. The cooling medium pump 113 can also be provided in the plasma generator 1. The cooling medium pump 113 may be configured by an appropriate pump such as a rotary pump or a reciprocating pump.

  FIG. 5 is a block diagram showing the configuration of the electric system of the reaction apparatus 100.

  The reactor main body 101 includes an electrode terminal 7, a sensor terminal 11, an apparatus-side electrode terminal 141 connected to the heater terminal 13, an apparatus-side sensor terminal 143, and an apparatus-side heater terminal 145. The plasma generator 1 is driven and controlled by power supplied from the reactor main body 101 through these terminals. Specifically, it is as follows.

  The power supply unit 121 is configured to include, for example, a battery, and converts DC power from the battery into AC power or DC power having an appropriate voltage for supply. Alternatively, AC power having a commercial frequency is converted into AC power or DC power having an appropriate voltage and supplied. The power of the power supply unit 121 is supplied to the control unit 123, the discharge control unit 125, the temperature detection unit 127, the heater driving unit 129, the fluid pump 109 to be processed, and the cooling medium pump 113.

  The discharge control unit 125 converts the power supplied from the power supply unit 121 into AC power having a voltage corresponding to the control signal from the control unit 123, and converts the converted power into the device-side electrode terminal 141 and the electrode terminal. 7 to the electrode 15. For example, the discharge control unit 125 includes a power supply circuit such as an inverter or a transformer. In the electrode 15, an amount of discharge corresponding to the voltage applied by the discharge control unit 125 is performed.

  For example, when the temperature detection element 19 is configured by a resistor whose resistance value changes due to a temperature change, the temperature detection unit 127 converts electric power supplied from the power supply unit 121 into DC power or AC power of an appropriate voltage. Then, the converted electric power is supplied to the temperature detection element 19 via the device-side sensor terminal 143 and the sensor terminal 11. The temperature detection element 19 detects the resistance value of the temperature detection element 19 and outputs a signal corresponding to the detected resistance value to the control unit 123. The temperature detection element 19 may calculate the temperature of the temperature detection element 19 based on the detected resistance value and output a signal corresponding to the calculated value to the control unit 123.

  The heater drive unit 129 converts the power supplied from the power supply unit 121 into DC power or AC power having a voltage corresponding to a control signal from the control unit 123, and converts the converted power into the apparatus-side heater electrode 145 and the heater. It is supplied to the heater 21 through the electrode 13. The heater driving unit 129 includes a power supply circuit such as a rectifier circuit or a transformer, for example. The heater 21 generates heat in an amount corresponding to the voltage applied by the heater driving unit 129.

  Each of the fluid pump 109 and the cooling medium pump 113 includes, for example, a motor as a pump drive source and a motor driver that drives the motor, although not particularly illustrated. The electric power supplied from the power supply unit 121 is converted into AC power or DC power having a voltage corresponding to a control signal from the control unit 123 and applied to the motor. The motor rotates at the number of rotations corresponding to the applied voltage, and consequently a force corresponding to the applied voltage is applied to the fluid to be processed and the cooling medium.

  The input unit 131 receives a user operation and outputs a signal corresponding to the user operation to the control unit 123. For example, the input unit 131 receives a drive start operation, a drive stop operation, various temperature setting operations related to temperature setting and flow rate control of the reaction apparatus 100, and outputs a signal corresponding to the operation. The input unit 131 includes, for example, a control panel including various switches and a keyboard.

  For example, although not particularly illustrated, the control unit 123 is configured by a computer including a CPU, a ROM, a RAM, and an external storage device. The control unit 123 outputs control signals to the discharge control unit 125, the heater driving unit 129, the fluid to be processed pump 109, and the cooling medium pump 113 based on signals from the temperature detection unit 127 and the input unit 131.

  For example, when a signal corresponding to the driving start operation of the reaction apparatus 100 is input from the input unit 131, the control unit 123 sends a control signal to the discharge control unit 125 so as to start supplying power to the electrode 15. When a signal corresponding to a drive stop operation of the reaction apparatus 100 is input from the input unit 131, a control signal is output to the discharge control unit 125 so as to stop the supply of power to the electrode 15.

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In this case, a control signal is output to the discharge controller 125 so that the power supplied to the electrode 15 is increased from the power supplied during normal operation, and when the plasma generator 1 reaches the target temperature, A control signal is output to the discharge controller 125 so that the power supplied to the electrode 15 is maintained at the power supplied during normal operation.

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In this case, a control signal is output to the heater drive unit 129 so that power is supplied to the heater 21 or power supplied to the heater 21 is increased. When the plasma generator 1 reaches the target temperature, a control signal is output to the heater driving unit 129 so that the power supplied to the heater 21 is reduced or the supply of power to the heater 21 is stopped. To do.

  In addition, for example, the control unit 123 may detect the temperature detected by the temperature detection unit 127 and the temperature at which the plasma generator 1 can efficiently generate plasma, or the plasma generator 1 and the reaction device main body 101. Compared with a predetermined target temperature set as a safe operating temperature, if the detected temperature is higher than the target temperature, the flow rate of the cooling medium is increased, and if it is lower, the flow rate of the cooling medium is decreased In this manner, a control signal is output to the cooling medium pump 113.

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In this case, when it is determined that the flow rate of the fluid to be processed is low and reached, a control signal is output to the pump 109 for fluid to be processed so as to increase the flow velocity of the fluid to be processed.

  Further, for example, the control unit 123 compares the temperature detected by the temperature detection unit 127 with a predetermined temperature range set as a temperature at which the plasma generator 1 or the reaction device main body unit 101 is safely operated, When the detected temperature exceeds the set temperature range, a control signal is output so as to notify the occurrence of abnormality to a notifying unit such as a display device or a speaker (not shown).

  According to the second embodiment described above, the reactor 100 generates plasma in the plasma generator 1 of the first embodiment, the supply pipe 105 that supplies the fluid to be processed to the discharge space 5, and the discharge space 5. And a discharge pipe 107 for discharging the reaction fluid obtained by chemically changing the fluid to be treated. As in the first embodiment, the durability of the plasma generator 1 can be improved and the plasma generator 1 can be improved. As a result, the durability of the reactor 100 can be improved and the size reduction effect can be obtained.

(Third embodiment)
FIG. 6 is a cross-sectional view showing a configuration of a light source device 200 according to the third embodiment of the present invention.
In addition, about the structure similar to 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and description is abbreviate | omitted.

  The light source device 200 includes a plasma generator 1 ′ having the same configuration as that of the first embodiment, and is configured as a light source device that emits light using plasma generated by the plasma generator 1 ′. The light source device 200 is configured as, for example, a fluorescent lamp, a mercury lamp, or a sodium lamp. In the following, the portion of the light source device 200 other than the plasma generator 1 ′ may be referred to as the light source device main body 201.

  The plasma generator 1 ′ of the third embodiment is the same as that of the first embodiment in that a plurality of electrodes 15 are connected to each other by electrode conductive paths 207 provided outside the base 3 ′. It differs from body 1. The electrode conductive path 207 may be provided in the plasma generator 1 ′ or may be provided in the light source device main body 201. The plasma generator 1 of the first embodiment may be used in the third embodiment.

  In the first embodiment, the reflectance of the surface of the substrate 3 is not particularly mentioned. However, the substrate 3 ′ of the third embodiment is a surface that forms the discharge space 5 or the surface of the substrate 3 ′. At least a part of the outer peripheral surface (first to sixth surfaces S1 to S6 in FIG. 1), or the entire surface of the base 3 'including both of them is mirror-finished, and the reflectance is relatively high. . For example, the reflectance is preferably 50% or more. As a dielectric material constituting such a substrate 3, a white material is preferable, and examples thereof include alumina ceramics, zirconia ceramics, cordierite ceramics, and yttria ceramics. In particular, when the plasma generator 1 'generates ultraviolet light or near-ultraviolet light, alumina ceramics, zirconia ceramics, cordierite ceramics, and yttria ceramics have high reflectivity for ultraviolet light and near-ultraviolet light, as well as ultraviolet light and near-ultraviolet light. Deterioration against ultraviolet light can also be suppressed.

  Preferably, the dielectric constituting the substrate 3 ′ should have a crystal phase area ratio higher than the glass phase area ratio on the surface exposed to the discharge space 5. With this configuration, the substrate 3 ′ can be effectively prevented from being etched by the plasma generated in the discharge space 5. That is, the surface of the dielectric exposed to the discharge space 5 has resistance to etching by plasma by increasing the ratio of the crystal phase bonded by the covalent bond having a very high bonding force. Therefore, it is possible to effectively prevent the ceramic fine powder etched in the discharge space from being scattered, and as a result, it is possible to stably obtain single light having a uniform wavelength of the light source.

  The other configuration of the plasma generator 1 ′ is the same as that of the plasma generator 1. Although the discharge space 5 has three layers in FIG. 1 and the discharge space 5 has four layers in FIG. 6, these are merely examples for convenience of explanation.

  The light source device main body 201 includes a casing 209 that houses a plasma generator 1 ′ and has a translucent portion 209 a that can emit light emitted by the plasma generator 1 ′. The translucent part 109a is provided in a part of the housing 209, and light from the light source device 200 is emitted in a predetermined direction. That is, the light source device 200 is configured as a light source having directivity. However, the light source device 200 may be configured as a light source that does not have directivity, with the translucent portion 209a provided over most or the entire surface of the housing 209.

  The casing 209 formed to have directivity includes an airtight container 203 that houses the plasma generator 1 ′ and has a light shielding property, and a translucent member 205 that closes the opening 203 a of the airtight container 203. . That is, the entire casing 209 is configured by the airtight container 203 and the translucent member 205, and the translucent portion 209 a is configured by the opening 203 a and the translucent member 205.

  The casing 209 is configured to form a sealed space SP. A gas for generating plasma is enclosed in the sealed space SP. For example, if the light source device 200 is a fluorescent lamp, the gas enclosed in the sealed space SP is a rare argon gas containing about 200 to 300 Pa containing mercury particles. If the light source device 200 is a mercury lamp, the gas is mercury. If the light source device 200 is a sodium lamp, the vapor is about 0.5 Pa sodium vapor mixed with neon or argon gas.

  The plasma generator 1 'is arranged in the sealed space SP so that the opening direction of the discharge space 5 faces the light transmitting part 209a. The hermetic container 203 is made of, for example, a suitable insulating material. For example, it is made of ceramic. The translucent member 205 is made of an appropriate material having translucency and insulation, for example. For example, it is made of glass. When the light source device 200 is a fluorescent lamp, a fluorescent paint is applied to the translucent member 205.

  Inside the housing 209, a reflecting portion 211 capable of reflecting light is provided. The reflection part 211 is formed by, for example, mirror-finishing the inner surface of the hermetic container 203 made of ceramic. Alternatively, it is formed by providing a reflecting member at an appropriate position inside the housing 209 such as arranging a mirror on the inner surface of the airtight container 203. The reflectance of the reflection part 209b is, for example, 50% or more.

  The light source device main body 201 is similar to the reaction device main body 101 of the second embodiment, as shown in FIG. 4, the refrigerant source 111 for supplying a cooling medium to the plasma generator 1 ′, and the flow tube 50. The cooling medium pump 113 may be provided. Further, the configuration of the electrical system of the light source device main body 201 is different from the configuration of the electrical system of the reaction device main body 101 of the second embodiment shown in FIG. The same.

  In the light source device 200 having the above configuration, when AC power is supplied to the electrode conductive path 207 and plasma is generated in the discharge space 5 of the plasma generator 1, the excited atoms generate light, and the light is transmitted. The light exits from the light section 209a. The light source device 200 may be used as, for example, general indoor lighting or outdoor lighting, or may be used as a light source of an exposure apparatus.

  According to the third embodiment described above, the same plasma generator 1 ′ as in the first embodiment and the plasma generator are accommodated, and light emitted by plasma generation in the discharge space 5 is emitted. Since the housing 209 having the light transmitting portion 209a is provided, the effect of improving the durability of the plasma generator 1 'and reducing the size of the plasma generator 1' can be obtained as in the first embodiment. As a result, the effect of the durability improvement and size reduction of the light source device 200 is acquired.

  In addition, since the base 3 'is formed as one member and has no interface, it is possible to prevent light from entering the interface and reducing the light intensity.

  Since a reflection part 211 that reflects light emitted by the generation of plasma in the discharge space is provided in the housing 209, light incident on a surface other than the translucent part 209a on the inner surface of the housing 209 is reflected. Thus, light can be emitted from the translucent portion 209a with a higher amount of light.

  Further, since the base body 3 ′ also functions as a reflecting portion, light generated in the discharge space 5 is suppressed from being absorbed by the surface forming the discharge space 5, and light is efficiently emitted from the discharge space 5. In addition, it is possible to suppress the light in the housing 209 from being absorbed by the surface forming the outer shape of the base 3 ′, and to emit light with a higher amount of light from the translucent portion 209 a.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The plasma generator is not limited to those that generate plasma by so-called high-frequency discharge, as long as plasma is generated by discharge in the discharge space by applying a voltage to the electrodes. For example, a plasma may be generated by a DC discharge in which a DC voltage is applied to the opposing electrode to discharge, or a relatively low frequency AC voltage (for example, an AC voltage of 50 Hz to 100 kHz) is applied to the electrode. The plasma may be generated by a low frequency discharge to be applied, or the plasma may be generated by a microwave discharge in which an AC voltage having a very high frequency (for example, an AC voltage of 1 GHz or more) is applied to the electrode. May be.

  The electrodes are not limited to what constitutes a pair of electrodes facing each other, that is, a so-called capacitor type, and may be a coil type. The electrodes are not limited to those disposed outside the discharge space, and may be disposed inside the discharge space. The electrodes are not limited to those embedded in the substrate, and may be exposed from the substrate. When the substrate is formed of a laminate of dielectric layers, the electrodes are not limited to those provided parallel to the dielectric layers, and may be provided at appropriate positions with respect to the dielectric layers. 7 and 8 illustrate a modification.

  FIG. 7A is a side view showing a plasma generator 300 in which a pair of electrodes 305 are provided inside a discharge space 303 formed in the base 301. The base 301 is configured by stacking a plurality of dielectric layers, for example, as in the first embodiment. The electrode 305 is, for example, on the surface of the dielectric layer that forms the discharge space 303 (in the first embodiment, the bottom surface of the recess 33D of the fourth dielectric layer 31D and the bottom surface of the recess 33F of the sixth dielectric layer 31F). The conductive paste is disposed, and the laminated dielectric layer is baked to form.

  FIG. 7B is a perspective view showing a plasma generator 310 in which a three-dimensional coiled electrode 315 is provided outside a discharge space 313 formed in the substrate 311, as seen through the substrate 311. The base 311 is configured by stacking a plurality of dielectric layers, for example, as in the first embodiment. In the electrode 315, the parallel portion 315a parallel to the dielectric layer is formed, for example, in the same manner as the electrode 15 of the first embodiment, with the conductive paste disposed on the surfaces of the dielectric layers that are overlapped with each other. Is formed. Of the electrode 315, the through portion 315b penetrating the dielectric layer is filled with a conductive paste in the hole formed in the dielectric layer, for example, like the orthogonal portion 25a of the electrode conductive path 25 of the first embodiment. The stacked dielectric layers are formed by firing.

  FIG. 7C is a perspective view showing a plasma generator 320 in which a three-dimensional coiled electrode 325 is provided in a discharge space 323 formed in the base 321, as seen through the base 321. The base 321 is configured by laminating a plurality of dielectric layers, for example, as in the first embodiment. The electrode 325 is, for example, a surface of the dielectric layer on which the discharge space 325 is formed (in the first embodiment, the bottom surface and the side surface of the recess 33D of the fourth dielectric layer 31D, the divided layer 31E- of the fifth insulating layer 31E). 1, the conductive paste is disposed on the opposing surface of 31E-2, the bottom surface and the side surface of the recess 33F of the sixth dielectric layer 31F, and the stacked dielectric layers are baked to form.

  FIG. 8A is a perspective view showing a plasma generator 330 in which a planar coil-like electrode 335 is provided in a discharge space 333 formed in the base 331, as seen through the base 331. The base 331 is configured by stacking a plurality of dielectric layers, for example, as in the first embodiment. In the electrode 335, a conductive paste is disposed on the surface of the dielectric layer that forms the discharge space 335 (in the first embodiment, the bottom surface of the recess 33D of the fourth dielectric layer 31D), and the laminated dielectric layer is fired. Is formed.

  FIG. 8B is a side view showing a plasma generator 340 in which a pair of opposing electrodes 345 are provided inside a discharge space 343 formed in the base 341, as in FIG. 7A. As in the first embodiment, for example, the base 331 includes a first dielectric layer 347A and a second dielectric layer 347B (hereinafter simply referred to as “dielectric layer 347”, which may not be distinguished from each other). Configured. The electrode 341 is provided so as to be orthogonal to the dielectric layer 347. That is, the electrode 341 is not provided in parallel with the dielectric layer 347. The electrode 341 is formed, for example, by disposing a conductive paste on the surface of the dielectric layer where the discharge space 335 is formed and firing the laminated dielectric layer.

  The shape and size of the discharge space may be set as appropriate and are not limited to a rectangular parallelepiped shape. For example, a cylindrical shape may be sufficient. There may be one discharge space. When there are a plurality of discharge spaces, the shape, size, and interval may not be the same. For example, the interval between the discharge spaces on the position side where heat dissipation is difficult may be made larger than the interval between the discharge spaces at other positions. When electrodes are provided alternately with a plurality of discharge spaces, the intervals between the plurality of electrodes may not be uniform, and the intervals between the electrodes and the discharge spaces may not be uniform.

  The flow path formed in the base of the plasma generator may have an appropriate shape. For example, the flow path may be branched. For example, in the first embodiment, the flow path 17 extending from the inflow connecting pipe 9A branches into a plurality of electrode cooling parts 17a, and then merges after passing through the electrode cooling part 17a to the outflowing connecting pipe 9B. You may make it extend. In other words, in the first embodiment, the plurality of electrode cooling parts 17a are connected in series, but the flow path 17 may be branched so that the plurality of electrode cooling parts 17a are connected in parallel. . In this case, a plurality of electrodes can be uniformly cooled.

  Moreover, the flow path may extend planarly or may extend three-dimensionally. The flow path is not limited to meandering but may extend in a spiral shape. The flow path may circulate inside the substrate. In other words, it does not have to communicate with the outside of the substrate. The number of flow paths is not limited to one as in the embodiment, and an appropriate number may be provided.

  Fig.9 (a) is a top view which shows the modification of a flow path. The flow path 352 extends meandering along the electrode 351. The flow path 352 is formed so that the cross-sectional area of the flow path center part 352a located at the center part of the electrode 351 is larger than the cross-sectional area of the flow path outer periphery part 352b located at the outer periphery part of the electrode 351. Accordingly, the central portion of the electrode 351 that is likely to be highly heated can be intensively cooled, and the entire electrode 351 can be efficiently cooled. The electrode 351 easily concentrates power in the center. If the dielectric constant of the cooling medium is lower than the dielectric constant of the substrate 3 and the flow path 352 extends between the discharge space and the electrode 351, the electrode 351 is provided. The dielectric constant on the center side of the covering dielectric can be made lower than that on the outer peripheral side, the voltage can be made uniform, and discharge can be suitably performed. As an example, the relative dielectric constant of water that can be used as a cooling medium is about 80, and ceramics that can be used as the material of the substrate (dielectric) are those having a relative dielectric constant lower than that of water. There exists a dielectric constant up to about 10,000.

  FIG.9 (b) is a top view which shows the other modification of a flow path. The channel 362 extends meandering along the electrode 361. The cross-sectional area of the flow path 362 is constant. The channel 362 is formed such that the interval between the channel central portions 362 a located at the center of the electrode 361 is smaller than the interval between the channel outer peripheral portions 362 b located at the outer periphery of the electrode 361. Therefore, the same effect as that of the modified example of FIG.

  Note that FIG. 9A and FIG. 9B may be combined. Also in the modification shown in FIGS. 9A and 9B, the electrodes are not limited to planar ones. For example, even if the three-dimensional coil shape shown in FIG. 7B is a plan view from the upper side of the paper surface of FIG. And the portion located on the outer peripheral portion of the electrode may satisfy the above relationship in the cross-sectional area and the flow path interval.

  FIG. 9C is a plan view showing still another modified example of the flow channel, specifically, a non-meandering flow channel. The flow path 372 extends in a coil shape so as to surround the electrode 371. In such a channel 372, as shown in FIG. 9A and FIG. 9B, the interval between the channel center portions 362a located at the center portion of the electrode 371 is located at the outer peripheral portion of the electrode 371. The flow path outer peripheral part 362b may be formed to be smaller than the interval between them, or the cross-sectional area of the flow path central part 372a may be formed to be larger than the cross-sectional area of the flow path outer peripheral part 372b.

  The fluid flowing through the flow path is not limited to the cooling medium. For example, a relatively high temperature fluid may be flowed through the flow path to quickly raise the temperature of the plasma generator to a temperature suitable for discharge.

1 is an external perspective view of a plasma generator according to a first embodiment of the present invention. The figure which shows the cross section in the II-II line | wire of FIG. The figure explaining the formation method of the plasma generator of FIG. The conceptual diagram which shows the structural structure of the reaction apparatus which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the electric system of the reaction apparatus of FIG. Sectional drawing which shows the structure of the light source device which concerns on the 3rd Embodiment of this invention. The figure which shows the modification of the electrode of a plasma generator. The figure which shows the other modification of the electrode of a plasma generator. The figure which shows the modification of the flow path of a plasma generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plasma generating body, 3 ... Base | substrate (dielectric material), 5 ... Discharge space, 15 ... Electrode, 17 ... Flow path.

Claims (10)

A dielectric having a discharge space and integrally formed to surround the discharge space;
A pair of layered electrodes which are embedded in the dielectric so as to face each other across the discharge space and can generate plasma in the discharge space;
An electrode conductive path embedded in the dielectric and connecting the electrode and an electrode terminal exposed to the outside of the dielectric;
A heater embedded in the dielectric;
A heater conductive path embedded in the dielectric and connecting the heater and a heater terminal exposed to the outside of the dielectric;
A temperature detecting element embedded in the dielectric;
A sensor conductive path embedded in the dielectric and connecting the temperature detecting element and a sensor terminal exposed to the outside of the dielectric;
With
The conductive path for the electrode, the conductive path for the heater, and the conductive path for the sensor partially extend in parallel to the electrode, and the other part extends in a direction opposite to the electrode, and the conductive path for the heater and the sensor In the case where the conductive path has a portion extending in the facing direction of the electrode, the portion extends in the facing direction of the electrode outside the electrode . A plurality of the discharge spaces are provided along a predetermined direction,
The plasma generator according to claim 1, further comprising a plurality of the electrodes arranged alternately with the plurality of discharge spaces in the predetermined direction. The plasma generator according to claim 2, wherein the plurality of electrodes are alternately connected to each other.   4. The plasma generator according to claim 1, wherein the dielectric has an area ratio of a crystal phase higher than an area ratio of a glass phase on a surface exposed to the discharge space. 5. .   5. The plasma generator according to claim 1, wherein a main component of at least a portion of the dielectric exposed in the discharge space is cordierite ceramics. The dielectric is formed by firing a plurality of laminated dielectric layers,
The plasma generator according to any one of claims 1 to 5, wherein the discharge space includes gaps between the plurality of dielectric layers formed by providing a hole in the dielectric layer. . The plasma generator according to any one of claims 1 to 6,
A supply unit capable of supplying a fluid to be treated to the discharge space;
And an electrode control unit capable of applying a voltage to the electrode so as to chemically change the fluid to be processed by generating plasma in the discharge space. The plasma generator according to any one of claims 1 to 6,
A light source device comprising: a housing having a light transmitting portion capable of containing the plasma generator and emitting light emitted by plasma generation in the discharge space. The light source device according to claim 8, wherein a reflection portion capable of reflecting light emitted by plasma generation in the discharge space is provided in the housing. The light source device according to claim 8, wherein the dielectric is white.

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