JP2005135727A - Vacuum terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum terminal with high reliability of electrical connection between a central conductor and an external terminal and high hermetic reliability.
A vacuum terminal is a vacuum terminal installed in a vacuum apparatus so that one end side is on an external atmosphere side and the other end side is on a vacuum atmosphere side, and includes a cylindrical outer conductor 1 and an inner portion of the outer conductor 1 The cylindrical ceramic member 2 is coaxially disposed and part of the outer peripheral surface is brazed to the inner peripheral surface of the outer peripheral conductor 1 over the entire circumference, and both end portions protrude from both end surfaces of the ceramic member 2. And a rod-shaped central conductor 3 provided on the central axis of the ceramic member 2 and having a groove 3a formed on one end surface on the external atmosphere side. One end portion on the external atmosphere side of the central conductor 3 is made of a fluororesin. Is fitted into the cylindrical member 4.
[Selection] Figure 1

Description

  The present invention relates to a vacuum terminal used for a terminal of a coaxial cable used in a semiconductor manufacturing apparatus or an electronic apparatus, and more particularly to a one-side jack type vacuum terminal having vacuum tightness.

  Conventional vacuum terminals generally have a cylindrical outer conductor, a central conductor disposed on the central axis of the outer peripheral conductor, and a cylindrical conductor that holds the central conductor electrically insulated from the central axis of the outer peripheral conductor. It is composed of an insulator. This insulator is generally made of a synthetic resin, and for example, an insulator made of polytetrafluoroethylene (PTFE) or the like has been used.

  However, such an insulator made of synthetic resin has a problem that it becomes electrically unstable due to thermal expansion and contraction and a softening phenomenon peculiar to the synthetic resin. Also, when used for input / output of signals to the vacuum vessel, since synthetic resin adhesive is used to fix the insulator, the internal gas due to the gas released from the synthetic resin adhesive or insulator itself There was a problem that problems such as an adverse effect on the vacuum atmosphere and a lack of airtightness due to thermal expansion and contraction occurred.

In order to solve such a problem, ceramics such as an alumina (Al ₂ O ₃ ) -based sintered body is used as the insulator. By using ceramics as an insulator and brazing the insulator with the outer conductor and the center conductor, it is possible to achieve highly airtight bonding and greatly reduce gas emission from the ceramics. High vacuum terminal.

  For example, as shown in FIG. 3, the one-side plug type vacuum terminal capable of terminal coupling on one side of the vacuum terminal includes a cylindrical outer conductor 11, a center conductor 13 disposed on the central axis of the outer conductor 11, A cylindrical insulator 12 that holds the central conductor 13 in a state of being electrically insulated from the central axis of the outer peripheral conductor 11, and a deep groove portion 13a for plugs is formed on the end surface of the central conductor 13 on the external atmosphere side. It is formed. The outer conductor 11 and the insulator 12, and the insulator 12 and the center conductor 13 are brazed and joined, so that the airtightness between the external atmosphere side and the vacuum atmosphere side can be maintained.

The outer conductor 11 and the center conductor 13 are made of a metal such as iron (Fe) -nickel (Ni) -cobalt (Co) alloy, and the insulator 12 is made of ceramics such as an Al ₂ O ₃ sintered body. As the brazing material, silver (Ag) -copper (Cu) brazing, Ag brazing, or the like is used.

  The vacuum terminal with such a structure is a one-sided jack type that is electrically stable and does not affect the atmosphere such as vacuum caused by the gas released from the material itself such as adhesive or insulator. It was functioning as a vacuum terminal.

Also, the plug groove 13a is formed at both ends of the center conductor 13, thereby functioning as a double-sided jack type vacuum terminal (see, for example, Patent Document 1 below).
JP 2003-229216 A

  However, in the conventional vacuum terminal shown in FIG. 3, when the outer conductor 11 and the insulator 12, and the insulator 12 and the center conductor 13 are brazed, the center conductor 13 is annealed and loses elasticity. If the external terminal is repeatedly attached to and detached from the plug groove 13a, the groove 13a of the center conductor 13 is deformed so as to expand, and the center conductor 13 and the external terminal cannot be electrically connected to each other.

  Further, when the center conductor 13 is deformed, stress due to the deformation of the center conductor 13 may be applied to the joint portion of the ceramic member 12 with the center conductor 13 in some cases. As a result, damage such as cracks occurs in the ceramic member 12, and it becomes impossible to hermetically block between both ends of the external atmosphere side end and the vacuum atmosphere end of the ceramic member 12, and it can function as a vacuum terminal. There was a problem of disappearing.

  Therefore, the present invention has been completed in view of the above problems, and an object of the present invention is to provide a vacuum terminal with high reliability of electrical connection between a central conductor and an external terminal and high hermetic reliability. is there.

  The vacuum terminal of the present invention is a vacuum terminal installed in a vacuum apparatus so that one end side is on the outside atmosphere side and the other end side is on the vacuum atmosphere side, and is coaxial with the cylindrical outer conductor and the outer conductor. A cylindrical ceramic member that is arranged in a shape and part of the outer peripheral surface is brazed to the inner peripheral surface of the outer peripheral conductor over the entire circumference, and the both ends protrude from the both end surfaces of the ceramic member. A vacuum terminal provided with a rod-shaped central conductor provided on a central axis of a ceramic member and having a groove formed on one end surface on the external atmosphere side, wherein one end portion on the external atmosphere side of the central conductor is made of a fluororesin It is characterized by being fitted in the cylindrical member.

  Preferably, in the vacuum terminal according to the present invention, the ceramic member has a step formed over the entire circumference between the end surface on the external atmosphere side and the through hole, and the central conductor is in the through hole on the outer peripheral surface. And a portion between the groove and the small-diameter portion is located on an end surface of the ceramic member on the external atmosphere side, and the cylindrical member has a tip portion. Is fitted in the step, and the tip is located in the small diameter portion.

  The vacuum terminal of the present invention is a vacuum terminal installed in a vacuum apparatus so that one end side is on the external atmosphere side and the other end side is on the vacuum atmosphere side, and is coaxial with the cylindrical outer conductor and the outer conductor. The cylindrical ceramic member is disposed on the outer peripheral surface of the ceramic member and a part of the outer peripheral surface is brazed to the inner peripheral surface of the outer peripheral conductor over the entire periphery, and the center of the ceramic member so that both end portions protrude from both end surfaces of the ceramic member. In a vacuum terminal provided with a rod-shaped center conductor provided on the shaft and having a groove formed on one end surface on the outside atmosphere side, one end portion on the outside atmosphere side of the center conductor is fitted into a cylindrical member made of fluororesin Therefore, even when the outer conductor and the ceramic member, and when the ceramic member and the center conductor are brazed, the center conductor is annealed and the elasticity of the groove is lowered, Since the forcibly supported by and fixed to Oite tubular member it can be prevented from being plastically deformed so as to expand a groove even central conductor to desorb the external terminal repeat in the groove. Therefore, even if the central conductor and the external terminal are repeatedly detached and attached, stress due to deformation of the central conductor can be prevented from being applied to the joint portion of the ceramic member with the central conductor, and the ceramic member is not damaged such as cracks. Thus, it is possible to reliably and hermetically block between the both end portions of the end portion on the external atmosphere side and the end portion on the vacuum atmosphere side of the ceramic member.

  In addition, since the fluororesin has appropriate elasticity and does not deteriorate due to repeated elastic deformation, the central conductor can always be elastically deformed at a grooved portion, and even if the external terminal is repeatedly attached and detached. Smooth desorption. Therefore, even if the external terminal is repeatedly attached and detached, the central conductor and the external terminal can be reliably electrically connected, and the central conductor and the external terminal can be smoothly attached and detached.

  Preferably, in the vacuum terminal according to the present invention, the ceramic member has a step formed over the entire circumference between the end surface on the external atmosphere side and the through hole, and the central conductor is located in the through hole on the outer peripheral surface. And a portion between the groove and the small diameter portion is located on the end surface on the external atmosphere side of the ceramic member, and the cylindrical member has the tip portion fitted into the step and the tip Is located in the small diameter part, the cylindrical member can be firmly fixed to the ceramic member, and the cylindrical member and the central conductor are always supported and fixed in place even if the external terminal is attached to or detached from the central conductor. become able to. As a result, the cylindrical member and the center conductor can be prevented from being displaced, the external terminal can be prevented from being easily detached, and the external terminal can be attached and detached more smoothly.

  In addition, since the small-diameter portion is formed in the portion located in the through hole on the outer peripheral surface of the center conductor, the center conductor and the bottom of the step of the ceramic member do not come into contact, and an external terminal is connected to the bottom of the step of the ceramic member. Since stress due to deformation of the central conductor at the time of attaching / detaching is not directly applied, it is possible to effectively prevent the ceramic member from being damaged such as cracks.

  Moreover, since the site | part between the groove | channel of a center conductor and a small diameter part is located in the end surface by the side of the external atmosphere of a ceramic member, a center conductor will be hold | maintained at a ceramic member via a cylindrical member, and a center conductor Can be prevented from swinging from the central axis of the ceramic member.

  As described above, the vacuum terminal of the present invention has high reliability of electrical connection between the central conductor and the external terminal and high airtight reliability.

  The vacuum terminal of the present invention will be described in detail below. FIG. 1A is a cross-sectional view showing an example of an embodiment of the vacuum terminal of the present invention, and FIG. 1B is an enlarged side view of a groove portion of a central conductor in the vacuum terminal of FIG. In these drawings, 1 is an outer conductor, 2 is a ceramic member, 3 is a center conductor, 3a is a groove of the center conductor 3, and 4 is a cylindrical member.

  The vacuum terminal of the present invention is installed in a vacuum apparatus so that one end side is on the external atmosphere side and the other end side is on the vacuum atmosphere side, and is arranged coaxially inside the cylindrical outer conductor 1 and the outer conductor 1. In addition, a cylindrical ceramic member 2 in which a part of the outer peripheral surface is brazed to the inner peripheral surface of the outer peripheral conductor 1 over the entire periphery, and the center of the ceramic member 2 so that both end portions protrude from both end surfaces of the ceramic member 2. A rod-shaped center conductor 3 provided on the shaft and having a groove 3a formed on one end surface on the outside atmosphere side, and one end portion on the outside atmosphere side of the center conductor 3 is fitted into a tubular member 4 made of fluororesin. It is.

  The outer conductor 1 and the center conductor 3 of the present invention are Fe-Ni-Co alloy, Fe-Ni alloy, Ni-Cu alloy, molybdenum (Mo), platinum (Pt), titanium (Ti), niobium (Nb), etc. Made of metal. In particular, it is preferable to select a metal having a thermal expansion coefficient close to that of the ceramic forming the ceramic member 2, so that the heat with the ceramic member 2 can be obtained even in a brazing process when manufacturing a vacuum terminal or in a high temperature use environment. It is possible to suppress the occurrence of a difference in expansion, and it is possible to prevent the ceramic member 2 from being damaged such as cracks.

  The outer peripheral conductor 1 and the central conductor 3 are manufactured in a predetermined shape by applying a conventionally known metal processing method such as rolling or punching to a metal ingot.

  The central conductor 3 is formed with a deep groove 3a for plug at one end side. The shape of the groove 3a in plan view may be various shapes such as a single character or a circle in addition to the cross shape shown in FIG. 1B, but the shape may be appropriately determined according to the shape of the external terminal attached to and detached from the groove 3a. That's fine.

  The groove 3a is formed by cutting the central conductor 3 formed in a rod shape.

The ceramic member 2 includes an Al ₂ O ₃ sintered body, an aluminum nitride (AlN) sintered body, a zirconia (ZrO ₂ ) sintered body, a silicon carbide (SiC) sintered body, and a silicon nitride (Si ₃ N). ₄ ) Made of a sintered ceramic.

For example, in the case of an Al ₂ O ₃ sintered body, it is manufactured as follows. That is, an acrylic binder (for example, polymethacrylic acid) and an appropriate amount of an organic solvent are added to a raw material powder such as Al ₂ O ₃ , silicon oxide (SiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO), and kneaded. Sintered body that becomes ceramic member 2 by filling the mold obtained by spray-drying into a mold and pressurizing the mold by applying pressure, and firing the molded body at a temperature of about 1600 ° C. Can be produced.

  In the ceramic member 2, a metal layer is formed on the surface of a part of the brazing part in contact with the outer peripheral conductor 1 and a part of contact with the central conductor 3. This metal layer is a metal layer having a two-layer structure of a metallized layer and a metal plating layer, and the thickness is preferably 5 to 30 μm. When the thickness is less than 5 μm, the adhesion strength of the metal layer is reduced due to the erosion of the brazing material, so that airtight breakage is likely to occur. If it is thicker than 30 μm, the stress applied to the metal layer increases due to the difference in thermal expansion coefficient between the metal layer and the ceramic member 2, and the metal layer is likely to crack. This metal layer is formed by depositing a Ni plating layer on a metallized layer made of molybdenum (Mo) -manganese (Mn), tungsten (W) -Mn, copper (Cu) -titanium (Ti), Ag-Cu-Ti, or the like. The two-layer structure.

  Then, the outer peripheral conductor 1 and the ceramic member 2 and the ceramic member 2 and the central conductor 3 are brazed at about 800 ° C. using a brazing material such as Ag—Cu brazing or Ag brazing.

  After the outer peripheral conductor 1 and the ceramic member 2 and the ceramic member 2 and the central conductor 3 are brazed, one end portion of the central conductor 3 on the outside atmosphere side is fitted into the cylindrical member 4 made of fluororesin, and the cylindrical member The end surface of the ceramic member 2 side of 4 and the ceramic member 2 are fixed by being bonded via a resin adhesive such as a synthetic resin adhesive. This cylindrical member 4 is manufactured in a predetermined shape by a conventionally known injection molding method or the like, and is made of tetrafluoroethylene resin (polytetrafluoroethylene; PTFE), tetrafluoroethylene-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer). Polymeric resin; ETFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin; PFA), and the like.

  Since the fluororesin constituting the tubular member 4 has moderate elasticity and does not deteriorate with respect to repeated elastic deformation, the elastic deformation of the central conductor 3 can be supported in the plug groove 3a. Even if the external terminal is repeatedly attached and detached, the external terminal can be smoothly attached to and detached from the groove 3a by elastic deformation without deterioration. Therefore, even if the external terminal is repeatedly attached and detached, the central conductor 3 and the external terminal can be reliably electrically connected, and the groove 3a of the central conductor 3 and the external terminal can be smoothly attached and detached. Since the fluororesin is resistant to heat and hardly deteriorates at a high temperature of about 200 ° C., the vacuum terminal can be used under a high temperature environment of about 200 ° C.

  In addition, one end of the central conductor 3 where the groove 3a on the outside atmosphere side is formed is fitted into the cylindrical member 4 made of fluororesin, so that the inner diameter of the cylindrical member 4 is substantially the same as the outer diameter of the central conductor 3. It is. As described above, the outer conductor 1 and the ceramic member 2, and the center of the ceramic member 2 and the center are formed by fitting one end portion of the central conductor 3 where the external atmosphere side groove 3 a is formed into the tubular member 4 made of fluororesin. Even when the center conductor 3 is annealed at a high temperature during brazing and the elasticity of the groove 3a is lowered when the conductor 3 is brazed, the center conductor 3 is forced to the cylindrical member 4 on the outer periphery of the groove 3a. Therefore, even if the external terminal is repeatedly attached to and detached from the groove 3a, it is possible to prevent plastic deformation so that the groove 3a of the center conductor 3 is expanded. Therefore, even if the central conductor 3 and the external terminal are repeatedly detached and attached, stress due to deformation of the central conductor 3 can be prevented from being applied to the joint portion of the ceramic member 2 with the central conductor 3, and the ceramic member 2 can be damaged such as cracks. In this way, the end surface on the external atmosphere side of the ceramic member 2 and the both end surfaces on the vacuum atmosphere side of the ceramic member 2 can be reliably hermetically blocked.

  In addition, since the fluororesin has an appropriate elasticity and does not deteriorate due to repeated elastic deformation, the center conductor 3 is always elastically supported and fixed at a portion where the groove 3a is provided. It can be deformed and can be smoothly detached even when the external terminals are repeatedly detached. Therefore, even if the external terminal is repeatedly attached and detached, the central conductor 3 and the external terminal can be reliably electrically connected, and the central conductor 3 and the external terminal can be smoothly attached and detached.

  Preferably, the outer diameter of the tubular member 4 is 1.5 to 3 times the inner diameter of the tubular member 4. With this shape, the elasticity of the cylindrical member 4 can be made the most appropriate, and even if the cylindrical member 4 is repeatedly elastically deformed, the cylindrical member 4 is elastic without causing damage such as elongation or cracks. The central conductor 3 can always be elastically deformed satisfactorily in the groove 3a serving as a plug even when the external terminal is repeatedly attached and detached.

  When the outer diameter of the cylindrical member 4 is less than 1.5 times the inner diameter of the cylindrical member 4, the thickness of the cylindrical member 4 is smaller than the diameter of the central conductor 3, and the cylindrical member 4 is repeatedly elastic. If deformed, the tubular member 4 may be damaged such as elongation or cracks. When the outer diameter of the cylindrical member 4 exceeds three times the inner diameter of the cylindrical member 4, a large force is required to elastically deform the cylindrical member 4 when the external terminal is attached and detached. It becomes difficult to elastically deform the central conductor 3 with an appropriate force in the groove 3a for plug when attaching / detaching.

  Further, the plug groove 3a of the central conductor 3 is located on the outside atmosphere side such as the atmosphere, whereby the cylindrical member 4 and the end surface of the cylindrical member 4 on the ceramic member 2 side and the ceramic member 2 are connected. The bonded portion bonded via a resin adhesive such as a synthetic resin adhesive is positioned on the outside atmosphere side, and the gas emitted from the cylindrical member 4 and the resin adhesive material itself adversely affects the vacuum atmosphere. Can be prevented.

  Preferably, in the vacuum terminal of the present invention, as shown in a cross-sectional view in FIG. 2, the ceramic member 2 is formed with a step 2a over the entire circumference between the end face on the external atmosphere side and the through hole, and the central conductor 3, a small diameter portion 3 b is formed in a portion located in the through hole on the outer peripheral surface, and a portion between the groove 3 a and the small diameter portion 3 b is located on the end surface of the ceramic member 2 on the external atmosphere side. The cylindrical member 4 may have a tip portion fitted in the step 2a and a tip located at the small diameter portion 3b.

  Since a part of the cylindrical member 4 is fitted in the step 2a and the tip of the cylindrical member 4 is located in the small diameter portion 3b, the tip of the cylindrical member 4 is slightly swollen into the small diameter portion 3b. Can be firmly fixed to the ceramic member 2, and the cylindrical member 4 and the central conductor 3 can always be supported and fixed at predetermined positions even if the external terminal is attached to and detached from the central conductor 3. As a result, the cylindrical member 4 and the center conductor 3 can be prevented from being displaced, the external terminals can be prevented from being easily detached, and the external terminals can be attached and detached more smoothly.

  Further, since the small diameter portion 3b is formed in the portion located in the through hole on the outer peripheral surface of the center conductor 3, the center conductor 3 and the bottom portion of the step 2a of the ceramic member 2 are not in contact with each other. Since the stress due to the deformation of the central conductor 3 at the time of attaching / detaching the external terminal is not directly applied to the bottom of the step, it is possible to effectively prevent the ceramic member 2 from being damaged such as a crack.

  Further, since the portion between the groove 3 a and the small diameter portion 3 b of the center conductor 3 is located on the end surface on the external atmosphere side of the ceramic member 2, the center conductor 3 is held by the ceramic member 2 via the tubular member 4. As a result, the central axis of the central conductor 3 can be prevented from swinging from the central axis of the ceramic member 2.

  Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

(A) is sectional drawing which shows the example of embodiment of the vacuum terminal of this invention, (b) is an enlarged side view of the groove | channel of the center conductor in the vacuum terminal of (a). It is sectional drawing which shows the other example of embodiment of the vacuum terminal of this invention. It is sectional drawing which shows the example of the conventional vacuum terminal.

Explanation of symbols

1: outer peripheral conductor 2: ceramic member 2a: step 3: central conductor 3a: groove 3b: small diameter portion 4: cylindrical member

Claims (2)

A vacuum terminal installed in a vacuum apparatus so that one end side is on the external atmosphere side and the other end side is on the vacuum atmosphere side, and is arranged coaxially inside the outer peripheral conductor and the outer periphery conductor A cylindrical ceramic member having a part of the surface brazed to the inner peripheral surface of the outer peripheral conductor over the entire circumference, and a central axis of the ceramic member so that both end portions protrude from both end surfaces of the ceramic member And a vacuum terminal having a rod-shaped central conductor having a groove formed on one end face on the external atmosphere side, and the one end portion on the external atmosphere side of the central conductor is fitted into a cylindrical member made of fluororesin. A vacuum terminal characterized by In the ceramic member, a step is formed over the entire circumference between the end surface on the external atmosphere side and the through hole, and the central conductor has a small diameter portion formed in a portion located in the through hole on the outer peripheral surface. And the portion between the groove and the small diameter portion is located on the end surface on the external atmosphere side of the ceramic member, and the cylindrical member has a tip portion fitted into the step and a tip. The vacuum terminal according to claim 1, wherein is located in the small diameter portion.

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