JP2019096522A - Insulation structure - Google Patents

Abstract

To provide an insulation structure having higher strength than the case where an insulation tube and a discharge regulation part are joined.SOLUTION: In an insulation structure 1 of a pair of electrodes 3, the electrodes 3 are supported at mutually spaced positions of a support member 2 while being insulated from each other. The support member 2 includes a discharge regulation part 5 which is configured as an insulator including a nonmetallic element and a metallic element and is also configured as a conductor in part in which the nonmetallic element is released and the metallic element is included. The pair of electrodes 3 are held by an insulator part of the support member 2, and the discharge regulation part 5 is interposed between the pair of electrodes 3 while the surface thereof is exposed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulating structure that insulates between a pair of electrodes.

  Conventionally, there is a vacuum valve, for example, as one having an insulating structure that insulates between a pair of electrodes. The vacuum valve is a cylindrical insulating container provided with a pair of electrodes in a support member. The support member is configured by joining a stainless steel discharge restricting portion formed in a cylindrical shape between a pair of insulating cylinders made of a ceramic insulator. The pair of electrodes are disposed to be separated from each other by the insulating cylinder at one end of the support member and the insulating cylinder at the other end, and are insulated from each other. This type of vacuum valve can raise the dielectric breakdown voltage of the inner and outer surfaces of the support member by providing the discharge restricting portion between the insulating cylinders (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 58-68818

  In the above-mentioned vacuum valve, since joining of an insulating cylinder and a discharge control part is joining of different materials, there existed a problem that joint strength became low.

  This invention is made in view of the above, Comprising: It aims at providing the insulation structure whose intensity | strength is higher than the case where an insulating cylinder and a discharge control part are joined.

  In order to solve the problems described above and achieve the object, the insulating structure according to the present invention is an insulating structure of an electrode in which a pair of electrodes are supported at mutually spaced positions of a support member in a mutually insulated state The support member is configured as an insulator containing a nonmetal element and a metal element, and has a discharge restricting portion formed as a conductor including the metal element by partial detachment of the nonmetal element. The pair of electrodes is held by the insulator portion of the support member, and the discharge restricting portion is interposed between the pair of electrodes with the surface exposed.

  Further, in the insulating structure according to the present invention, the support member is formed in a cylindrical shape, the electrodes are disposed at both ends of the support member, and the discharge restricting portion is a ring that goes around the inner periphery of the support member. It is good to be a part of the shape.

  Further, in the insulating structure according to the present invention, the support member is formed in a plate shape, one of the electrodes is disposed on one plate surface of the support member, and the other of the electrodes is of the support member. It is good to be arrange | positioned by one plate surface or the other plate surface, and the said discharge control part is formed so that the said one electrode may be enclosed.

  Further, in the insulating structure according to the present invention, the other electrode may be disposed on the other plate surface of the support member, and the discharge restricting portion may be a portion which goes around the side surface of the support member.

  Further, in the insulating structure according to the present invention, it is preferable that a plurality of the discharge restricting portions be provided so as to insulate each other.

  According to the above-described configuration, the support member is configured as an insulator including a nonmetallic element and a metallic element, and has a discharge restricting portion configured as a conductor including a metallic element from which the nonmetallic element is partially released. Thus, the bonding strength between the insulator portion of the support member and the discharge regulating portion is high, and the strength of the insulating structure can be increased.

FIG. 1 is a perspective view showing an insulating structure according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view showing the insulating structure shown in FIG. FIG. 3 is a longitudinal sectional view showing a method of forming the insulating structure shown in FIG. 1 by discharge irradiation. FIG. 4 is a cross-sectional explanatory view showing a method of forming the insulating structure shown in FIG. 1 by discharge irradiation. FIG. 5 is a perspective view showing an insulating structure according to a first modification of the first embodiment of the present invention. FIG. 6 is a perspective view showing an insulation structure according to a second modification of the first embodiment of the present invention. FIG. 7 is a perspective view showing an insulation structure according to a third modification of the first embodiment of the present invention. FIG. 8 is a longitudinal sectional view showing the insulating structure shown in FIG. FIG. 9 is a perspective view showing an insulation structure according to a fourth modification of the first embodiment of the present invention. FIG. 10 is a perspective view showing an insulation structure according to a fifth modification of the first embodiment of the present invention. FIG. 11 is a perspective view showing an insulating structure according to Embodiment 2 of the present invention. FIG. 12 is a longitudinal sectional view showing the insulating structure shown in FIG. FIG. 13 is a perspective view showing an insulation structure according to a first modification of the second embodiment of the present invention. FIG. 14 is a perspective view showing an insulation structure according to a second modification of the second embodiment of the present invention. FIG. 15 is a perspective view showing an insulation structure according to a third modification of the second embodiment of the present invention. FIG. 16 is a perspective view showing an insulation structure according to a fourth modification of the second embodiment of the present invention. FIG. 17 is a perspective view showing an insulation structure according to a fifth modification of the second embodiment of the present invention. FIG. 18 is a perspective view showing an insulation structure according to a sixth modification of the second embodiment of the present invention. FIG. 19 is a longitudinal sectional view showing the insulation structure shown in FIG.

  Hereinafter, with reference to the accompanying drawings, an example of a preferred embodiment of an insulating structure according to the present invention will be described in detail. The insulating structure of the first embodiment is used for a vacuum valve or a vacuum bushing, and the insulating structure of the second embodiment is used for a pattern of a MEMS, a DCB substrate of an IGBT module, or the like.

(Embodiment 1)
As shown in FIGS. 1 and 2, the insulating structure 1 according to the first embodiment includes a cylindrical support member 2 and a pair of electrodes 3 provided on both ends of the support member 2. The support member 2 is formed by integrally forming the support member main body 4 and the discharge restricting portion 5. The support member main body 4 is made of aluminum nitride containing nitrogen (a nonmetallic element) and aluminum (a metallic element), and exhibits an insulating property. The discharge restricting portion 5 is configured as a conductor by separating nitrogen from aluminum nitride to precipitate aluminum. The discharge restricting portion 5 is formed in a ring shape having a predetermined width that goes around the inner peripheral surface at the central portion of the support member 2 in a state in which the surface is exposed.

  The electrode 3 is formed of a conductor such as copper, and includes a first cylindrical portion 11 and a second cylindrical portion 12. The first cylindrical portion 11 is formed to have an outer diameter larger than the central hole of the support member 2, and the second cylindrical portion 12 is formed to an inner diameter that can be fitted into the central hole of the support member 2 There is. The first cylindrical portion 11 and the second cylindrical portion 12 are integrally formed in a coaxial arrangement. The electrode 3 is attached to both ends of the support member 2 by fitting the second cylindrical portion 12 into the center hole of the support member 2. The pair of electrodes 3 are in contact with only the support member main body 4 and are separated from the discharge restricting portion 5. The inside of the support member 2 can be maintained at a vacuum.

  Here, a method of forming a vacuum valve to which the insulating structure 1 is applied will be described. First, the support member main body 4 is formed in a cylindrical shape using aluminum nitride. Next, the ring-shaped discharge restricting portion 5 is formed on the inner peripheral surface of the support member main body 4. As a method of forming the discharge restricting portion 5, there is a method of irradiating the supporting member main body 4 with a laser, a method of irradiating the supporting member main body 4 with a discharge, and the like. When the laser is irradiated to the support member main body 4, nitrogen is separated from the aluminum nitride constituting the support main body 4 and aluminum is deposited. This aluminum portion is the discharge control portion 5. When forming the discharge control portion 5 by irradiating the laser, it is preferable to set the input power density of the laser to about 0.07 W · min / mm. Further, the focal point of the laser may be set on the surface of the portion of the support member main body 4 where the discharge restricting portion 5 is formed.

  The formation method of the discharge control part 5 by discharge irradiation is demonstrated based on FIG. 3, FIG. A pair of rectangular plate-shaped electrodes 20 and 21 are disposed on the inner peripheral surface of the support member main body 4. The pair of electrodes 20 and 21 are disposed so as to sandwich the portion where the discharge restricting portion 5 is to be provided. A back electrode 22 is provided on the outer peripheral surface of the support member main body 4 so as to cover the electrodes 20 and 21 on the inner peripheral surface of the support member main body 4. The back electrode 22 is connected to one of the electrodes 21 disposed on the inner circumferential surface of the support member main body 4 and grounded. Then, a high voltage is applied between the pair of electrodes 20 and 21 installed on the inner peripheral surface of the support member main body 4 by the high voltage power supply 23. The high voltage power supply 23 is grounded. Then, flashover occurs between the pair of electrodes 20 and 21, nitrogen is released from the aluminum nitride, and aluminum is deposited. This becomes the discharge control unit 5. When the thickness of the support member main body 4 is thin, there is a possibility that penetration failure may occur through the support member main body 4 before the flashover. Therefore, the voltage may be applied with the ratio of the thickness of the support member main body 4 to the distance between the pair of electrodes 20 and 21 being 1:10. Also, the voltage may be applied multiple times.

  When the discharge restricting portion 5 is formed, the support member 2 including the support member main body 4 and the discharge restricting portion 5 is completed. Thereafter, the pair of electrodes 3 and the support member 2 are joined. One electrode 3 is disposed so as to be able to be in contact with and separated from the other electrode 3. Then, the vacuum valve to which the insulating structure 1 is applied is completed.

  In the insulating structure 1 described above, the pair of electrodes 3 are arranged to be separated from each other, and the pair of electrodes 3 is supported by the insulator portion of the support member 2. , Are insulated. And since the discharge control part 5 is formed between a pair of electrodes 3, a dielectric breakdown voltage can be made high. Further, the support member 2 is configured as an insulator (support member main body 4) containing nitrogen and aluminum, and has a discharge restricting portion 5 configured as a conductor including aluminum, with nitrogen being partially released. . Therefore, as compared with the case where the metal is bonded to the insulator to form the discharge restricting portion, the bond between the discharge restricting portion 5 and the insulator portion (support member main body 4) of the support member 2 is strong. Moreover, since the metal material is unnecessary, the material cost can be reduced. In addition, since time for raising the temperature is required to bake the metal, the number of man-hours can be reduced and the cost can be reduced.

(Modification 1)
The insulating structure 1a of the first modification is different from the insulating structure 1 of the first embodiment in the shape of the discharge restricting portion, and the other portions are the same. In the insulating structure 1a of the first modification, as shown in FIG. 5, the discharge restricting portion 31 is formed in a spiral shape around the inner peripheral surface of the support member 2 at the central portion between the pair of electrodes 3. The discharge control unit 31 is not in contact with the pair of electrodes 3. A support member 32 is configured by the discharge restricting portion 31 and the support member main body 4. According to this configuration, the conductor portion appears a plurality of times in the middle of the path from the one electrode 3 to the other electrode 3, so that the dielectric breakdown voltage can be further increased.

(Modification 2)
The insulating structure 1b of the present modification 2 is different from the insulating structure 1 described in the first embodiment in the number of the discharge restricting portions, and the other parts are the same. In the insulating structure 1b of the second modification, as shown in FIG. 6, the discharge restricting portion 5 insulates each other in the axial direction of the support member 2 at the central portion between the pair of electrodes 3. And a plurality are formed. The discharge control unit 5 is not in contact with the pair of electrodes 3. A support member 33 is configured by the plurality of discharge restricting portions 5 and the support member main body 4. According to this configuration, the conductor portion appears a plurality of times in the path from the one electrode 3 to the other electrode 3, so that the dielectric breakdown voltage can be increased. According to this configuration, when a voltage is applied between the electrodes 3, the plurality of discharge regulating portions 5 have different potentials, so that the electric field can be relaxed stepwise. Therefore, the dielectric breakdown voltage can be further increased as compared with the case where the discharge control portion is in a spiral shape.

(Modification 3)
The insulating structure 1c of the third modification is different from the insulating structure 1 described in the first embodiment in the arrangement place of the discharge regulating portion, and the other is the same. In the insulating structure 1c of the third modification, as shown in FIG. 7 and FIG. 8, the discharge restricting portion 34 is formed in the center of the space between the pair of electrodes 3 in a ring shape that makes one turn around the outer peripheral surface of the support member 2. It is done. The discharge restricting portion 34 is not in contact with the pair of electrodes 3. A support member 35 is constituted by the discharge restricting portion 34 and the support member main body 4. According to this configuration, even if the outer surface side of the support member 35 is also kept in a vacuum state, the dielectric breakdown voltage of the outer peripheral surface of the support member 35 can be increased.

(Modification 4)
The insulating structure 1d of the fourth modification is different from the insulating structure 1 described in the first embodiment in the arrangement place and the shape of the discharge restricting portion, and the other is the same. In the insulating structure 1 d of the fourth modification, as shown in FIG. 9, the discharge restricting portion 36 is a central portion between the pair of electrodes 3 and spirals around the outer peripheral surface of the support member main body 4. Is formed. The discharge restricting portion 36 is not in contact with the pair of electrodes 3. The discharge restricting portion 36 and the support member main body 4 constitute a support member 37. According to this configuration, even when the outer surface side of the support member 37 is maintained in a vacuum state, the dielectric breakdown voltage of the outer peripheral surface of the support member 37 can be increased. In addition, since the conductor portion appears a plurality of times in the middle of the path from one electrode 3 to the other electrode 3, the dielectric breakdown voltage can be further increased.

(Modification 5)
The insulating structure 1 e of the fifth modification is different from the insulating structure 1 c of the third modification in the number of the discharge restricting portions, and the other parts are the same. In the insulating structure 1e of the fifth modification, as shown in FIG. 10, the discharge restricting portion 34 is a central portion between the pair of electrodes 3, and the outer peripheral surface of the supporting member 2 A plurality of gaps are formed to be isolated from each other at intervals. The plurality of discharge restricting portions 34 are not in contact with the pair of electrodes 3. A support member 38 is constituted by the plurality of discharge restricting portions 34 and the support member main body 4. According to this configuration, even when the outer surface side of the support member 38 is maintained in a vacuum state, the dielectric breakdown voltage of the outer peripheral surface of the support member 38 can be increased. In addition, since the conductor portion appears a plurality of times in the middle of the path from one electrode 3 to the other electrode 3, the dielectric breakdown voltage can be further increased. According to this configuration, when a voltage is applied between the electrodes 3, the plurality of discharge restricting portions 34 have different potentials, so that the electric field can be relaxed stepwise. Therefore, the dielectric breakdown voltage can be further increased as compared with the case where the discharge control portion is in a spiral shape.

  The discharge regulating portion may be provided on both the outer peripheral surface and the inner peripheral surface of the support member main body 4. Of the pair of electrodes 3, one of the electrodes 3 may be provided so as to be freely attached to and separated from the other electrode 3.

Second Embodiment
The insulating structure 41 of the second embodiment differs from the insulating structure 1 of the first embodiment in the shape of the support member and the shape of the electrode. The material of the supporting member main body 46 in the insulating structure 41 of the second embodiment is the same as the material of the supporting member main body 4 in the insulating structure 1 of the first embodiment. The material of the discharge restricting portion 45 in the insulating structure 41 of the second embodiment is the same as the material of the discharge restricting portion 5 in the insulating structure 1 of the first embodiment. The insulating structure 41 according to the second embodiment includes a support member 42 and a pair of electrodes 43 and 44 as shown in FIGS. 11 and 12. The support member 42 is formed in a rectangular flat plate shape. The support member 42 is formed by integrating the discharge restricting portion 45 and the rectangular flat support member main body 46. The pair of electrodes 43 and 44 are formed in a rectangular plate shape, and are stacked on one plate surface of the support member 42 at an interval. The pair of electrodes 43 and 44 is insulated.

  The discharge restricting portion 45 is formed in a square ring shape on one plate surface of the support member main body 46 so as not to be in contact with the pair of electrodes 43 and 44 and to surround the one electrode 43. A plurality of discharge restricting portions 45 are concentrically arranged, spaced apart from each other, and formed so as to be isolated from each other. The other electrode 44 is grounded. The discharge restricting portion 45 may be formed in a square ring shape so as to surround the other electrode 44. The method of forming the discharge restricting portion 45 is the same as the method of forming the discharge restricting portion 5 of the first embodiment. In the insulating structure 41, the discharge limiting portion 45 can increase the dielectric breakdown voltage. In addition, the support member 42 is configured as an insulator (support member main body 46) containing nitrogen and aluminum, and has a discharge restricting portion 45 configured as a conductor including aluminum, with nitrogen being partially released. . Therefore, the connection between the discharge restricting portion 45 and the insulator portion (support member main body 46) of the support member 41 is strong.

(Modification 1)
The insulating structure 41a of the first modification is different from the insulating structure 41 described in the second embodiment in the portion where the discharge regulating portion is formed, and the other portions are the same. In the insulating structure 41 a of the first modification, as shown in FIG. 13, the discharge restricting portion 45 is formed on the support member main body 46 so as to surround the one electrode 43 and with the pair of electrodes 43 and 44. It is formed in a square, ring shape that does not touch. A plurality of discharge restricting portions 45 are concentrically arranged around the electrode 43, and a plurality of the discharge restricting portions 45 are formed so as to be isolated from each other at intervals. The other discharge restricting portion 45 is formed in a square and ring shape on the support member main body 46 so as to surround the other electrode 44 and not in contact with the pair of electrodes 43 and 44. The other discharge restricting portions 45 are concentrically arranged around the electrode 44, and a plurality of the discharge restricting portions 45 are formed so as to be isolated from each other at intervals. The other electrode 44 is grounded. A support member 51 is constituted by the discharge restricting portion 45 surrounding one electrode 43, the discharge restricting portion 45 surrounding the other electrode 44, and the support member main body 46. According to this configuration, since the discharge restricting portion 45 is disposed not only around one electrode 43 but also around the other electrode 44, the dielectric breakdown voltage can be further enhanced.

(Modification 2)
The insulating structure 41b of the second modification is different from the insulating structure 41 described in the second embodiment in the shape of the discharge regulating portion, and the other portions are the same. In the insulating structure 41 b of the second modification, as shown in FIG. 14, the discharge regulating portion 52 is not in contact with the pair of electrodes 43 and 44 on the support member main body 46 and around one of the electrodes 43. It is formed in a spiral shape so as to surround. The discharge restricting portion 52 may be formed in a spiral shape so as to surround the other electrode 44. The discharge restricting portion 52 and the support member main body 46 constitute a support member 53.

(Modification 3)
The insulating structure 41c of the third modification is different from the insulating structure 41b described in the second modification in the portion where the discharge restricting portion is formed, and the other portions are the same. In the insulating structure 41c of the third modification, as shown in FIG. 15, the discharge restricting portion 52 is formed on the support member main body 46 so as to surround the one electrode 43 and with the pair of electrodes 43 and 44. It is formed in a non-contacting spiral shape. The other discharge restricting portion 52 is formed on the support member main body 46 in a spiral shape so as to surround the other electrode 44 and not in contact with the pair of electrodes 43 and 44. A support member 54 is configured by the discharge restricting portion 52 surrounding one of the electrodes 43, the discharge restricting portion 52 surrounding the other of the electrodes 44, and the support member main body 46. According to this configuration, since the discharge restricting portion 45 is disposed not only around one electrode 43 but also around the other electrode 44, the dielectric breakdown voltage can be further enhanced.

(Modification 4)
The insulating structure 41d of the fourth modification is the same as the insulating structure 41 described in the second embodiment except for the shape and arrangement position of the other electrode. In the insulating structure 41 d of the fourth modification, as shown in FIG. 16, the other electrode 55 is formed in the same shape as the support member main body 46 and is stacked on the other plate surface of the support member main body 46. The pair of electrodes 43 and 55 are not in contact with the discharge restricting portion 45. The pair of electrodes 43 and 55 is insulated. In the fourth modification, the other electrode 55 is grounded, but instead of the other electrode 55, one electrode 43 may be grounded. According to this configuration, the same effect as the insulating structure 41 of the second embodiment can be obtained.

(Modification 5)
The insulating structure 41 e of the present modification 5 is different from the insulating structure 41 b described in the modification 2 in the shape and arrangement position of the other electrode, and the other parts are the same. In the insulating structure 41 e of the fifth modification, as shown in FIG. 17, the other electrode 55 is formed to have the same size as the support member main body 46 and is stacked on the other plate surface of the support member main body 46. The pair of electrodes 43 and 55 are not in contact with the discharge restricting portion 52. The pair of electrodes 43 and 55 is insulated. In the fifth modification, the other electrode 55 is grounded, but instead of the other electrode 55, one electrode 43 may be grounded. According to this configuration, it is possible to obtain the same effect as the insulating structure 41b of the second modification.

(Modification 6)
The insulating structure 41f of the present modification 6 is different from the insulating structure 41d described in the modification 4, the configuration of the support member main body, and the position of the discharge regulating portion, and the other components are the same. In the insulating structure 41f of the sixth modification, as shown in FIGS. 18 and 19, the supporting member main body 61 is a plate-shaped insulating member 64, 65, and the insulating member whose end face is the discharge regulating portion 62. 64 and insulating members 65 whose end faces remain as insulators are alternately stacked. The discharge restricting portion 62 is formed in a square ring shape which exposes the surface and goes around the side surface of the support member main body 61. A plurality of discharge restricting portions 62 are formed so as to be mutually isolated at intervals in the thickness direction of the support member main body 61. The discharge restricting portion 62 is configured not to be in contact with the pair of electrodes 43 and 55. The discharge restricting portion 62 and the support member main body 61 constitute a support member 63. In the sixth modification, the other electrode 55 is grounded, but instead of the other electrode 55, one electrode 43 may be grounded. According to this configuration, even when the discharge restricting portion can not be formed on the plate surface of the support member main body 61, the discharge restricting portion can be formed, and the same effect as the insulating structure 41 of the second embodiment can be obtained. .

  In the above-mentioned embodiment and modification, although a supporting member main part is formed with aluminum nitride and a discharge control part is formed with aluminum, it is not restricted to this. The support member main body is formed of an insulator formed of a metal element and a nonmetal element, and the discharge control portion is formed of a conductor formed of a metal element formed by separating the nonmetal element from the insulator of the support member body. Just do it.

DESCRIPTION OF SYMBOLS 1 insulation structure 2 support member 3 electrode 4 support member main body 5 discharge control part 11 1st cylindrical part 12 2nd cylindrical part

Claims (5)

An insulating structure of an electrode in which a pair of electrodes are supported at mutually spaced positions of a support member in a mutually insulated state,
The support member is configured as an insulator including a nonmetallic element and a metallic element, and has a discharge restricting portion configured as a conductor including the metallic element from which the nonmetallic element is partially separated.
The pair of electrodes is held by an insulator portion of the support member,
The said discharge control part is interposed between the said pair of electrodes in the state which exposed the surface, The insulation structure characterized by the above-mentioned.   The support member is formed in a cylindrical shape, the electrodes are disposed at both ends of the support member, and the discharge restricting portion is a ring-shaped portion that goes around the inner periphery of the support member. The insulation structure according to claim 1.   The support member is formed in a plate shape, one of the electrodes is disposed on one plate surface of the support member, and the other of the electrodes is on one plate surface of the support member or the other plate surface. The insulating structure according to claim 1, wherein the discharge restricting portion is disposed so as to surround the one of the electrodes.   The insulating structure according to claim 3, wherein the other electrode is disposed on the other plate surface of the support member, and the discharge restricting portion is a portion that goes around the side surface of the support member.   The insulating structure according to any one of claims 1 to 4, wherein a plurality of the discharge restricting portions are provided so as to be insulated from each other.

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