JP4894361B2 - surge absorber - Google Patents

Description

  The present invention relates to a surge absorber that protects various devices from abnormal voltage (surge voltage).

  Electric shock caused by surge voltage such as lightning surge, static electricity, etc., such as telephone, facsimile, modem and other electronic equipment for communication equipment connected to communication line, electronic equipment connected to power line, antenna or CRT drive circuit, etc. A surge absorber is connected to the susceptible part in order to prevent the electronic device and the printed circuit board on which this device is mounted from being damaged due to thermal damage or fire due to abnormal voltage.

In such a surge absorber, an insulating tube surrounding a discharge space is fixed between a pair of terminal electrode members, and the inner surfaces of both terminal electrode members are formed to protrude toward the other terminal electrode member. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2005-63721

  By the way, the terminal electrode member and the insulating tube are fixed by brazing, but with the downsizing, the brazing material that has been melted during brazing crawls up the surface of the terminal electrode member, leading to the discharge start surface at the tip. There is a problem that it adheres easily. When the brazing material adheres to the discharge start surface, the material as the electrode member is changed to the brazing material, which causes a problem that the discharge starting voltage changes.

  The present invention provides a surge absorber in which a brazing material is prevented from adhering to a discharge start surface and a discharge start voltage is stabilized in a surge absorber in which a terminal electrode member and an insulating tube are fixed by brazing. For the purpose.

In the surge absorber according to the present invention, an insulating tube surrounding a discharge space is fixed between a pair of terminal electrode members by brazing, and the inner surface of the pair of terminal electrode members faces the other terminal electrode member. protrusion electrodes protruding Te is fixed by being inserted the respective small projections than base end formed projecting electrodes of the projecting electrode into the hole of the terminal electrode member, the terminal electrode member and the protruding electrode A brazing material stopper means for restricting the creeping of the molten brazing material to the discharge start surface of the protruding electrode is formed in a groove shape along the circumferential direction between the inner surface and the inner surface .

In this surge absorber, even if the molten brazing material reaches the base end of the protruding electrode during brazing, the creeping up to the discharge starting surface is regulated by the brazing material stopper means, so the discharge starting surface itself is the electrode. Ru can be maintained in the member.

When the brazing material stopper means is a recess, it is formed in a groove shape along the circumferential direction at a position avoiding the discharge start surface of the protruding electrode, so that a relatively large volume for storing the molten brazing material is secured. can do.

    Since the terminal electrode member is formed in a flat surface from the fixing portion to the insulating tube to the fixing portion of the protruding electrode, the brazing material interposed between the insulating tube and the terminal electrode member is the terminal electrode member. It is possible to reach the joint portion between the protruding electrode and the terminal electrode member through the surface of the surface, and to secure the fixing between the protruding electrode and the terminal electrode member.

  The surge absorber according to the present invention is provided with the brazing material stopper means on the projecting electrode, so that the molten brazing material is prevented from scooping up the projecting electrode during brazing and reaching the discharge starting surface. The material as the electrode member can be maintained as it is, and the discharge start voltage as the surge absorber can be stabilized.

A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the surge absorber 1 according to the present embodiment has a pair of opposed terminal electrode members 2 and 3, and these terminal electrode members 2 and 3 are arranged at both ends so that the inside is argon (Ar). Insulating tube 4 made of ceramics, glass or the like sealed with a gas such as, and projecting electrodes 5 and 6 provided on terminal electrode members 2 and 3 respectively.

  The pair of terminal electrode members 2 and 3 is Kovar (KOVAR: registered trademark) which is an alloy of nickel (Ni), cobalt (Co) and iron (Fe) or 42 alloy which is an alloy of nickel (Ni) and iron (Fe). And is formed as a flat plate having the same outer diameter as that of the insulating tube 4.

On the other hand, the insulating tube 4 is made of ceramics such as alumina (Al ₂ O ₃ ), glass, or the like, and has an outer periphery that matches the outer periphery of the terminal electrode members 2 and 3. Both end faces of the insulating tube 4 are provided with metallized layers 7 having a two-layer structure of a molybdenum (Mo) -tungsten (W) alloy layer and a nickel (Ni) layer. The insulating tube 4 has a pair of terminal electrode members 2 and 3 fixed to an end face provided with a metallized layer 7 via a silver (Ag) copper (Cu) -based frame-like brazing material 8. The internal space 9 is closed, and argon gas is sealed inside.

    The protruding electrodes 5 and 6 are fixed to the center positions of the inner surfaces of the terminal electrode members 2 and 3 so as to face each other along the axial direction of the insulating tube 4. These protruding electrodes 5 and 6 are formed in a cylindrical shape from titanium (Ti), nickel (Ni), or an alloy of nickel (Ni) and iron (Fe), etc., and the lengths thereof are both terminal electrode members 2, 3. The distance between the two protruding electrodes 5 and 6 is a trigger gap 11, and the tip surface of both protruding electrodes 5 and 6 is a discharge start surface 12. In this case, a through hole 13 is formed at the center of the terminal electrode members 2 and 3, and a protrusion 14 having an outer diameter that can be tightly fitted to the through hole 13 is formed on the protruding electrodes 5 and 6. And the protruding electrodes 5 and 6 are fixed to the terminal electrode members 2 and 3, respectively. Further, the protrusions 14 of the protruding electrodes 5 and 6 are formed longer than the length of the through hole 13, and in the circumferential direction between the inner surfaces of the terminal electrode members 2 and 3 while being press-fitted into the through hole 13. An annular recess 15 extending along the line is formed.

Next, a method for manufacturing the surge absorber 1 of the present embodiment having the above configuration will be described.
First, the pair of terminal electrode members 2 and 3 and the protruding electrodes 5 and 6 are formed. Then, the protrusions 14 of the protruding electrodes 5 and 6 are press-fitted and fixed in the through holes 13 of the terminal electrode members 2 and 3.

Next, a molybdenum (Mo) -tungsten (W) alloy layer and a nickel (Ni) layer are formed in this order on both end faces of the insulating tube 4 to improve the wettability with the brazing material 8. Form.
Then, a solid brazing material 8 is installed in a frame shape along the peripheral edge on the terminal electrode member 2 to which the protruding electrode 5 is fixed, and one end face of the insulating tube 4 is overlaid on the brazing material 8. Install. Further, the brazing material 8 is placed on the upper end surface of the insulating tube 4, and the terminal electrode member 3 with the protruding electrode 6 fixed thereon is placed and temporarily assembled.

After sufficiently evacuating in such a temporarily assembled state, heating is performed in a sealing gas atmosphere, the frame-shaped brazing material 8 is melted and sealed, and then rapidly cooled to manufacture the surge absorber 1.
In this manufacturing process, the brazing material 8 between the two terminal electrode members 2 and 3 and the insulating tube 4 is in a molten state, and the molten brazing material 8 ′ of the terminal electrode members 2 and 3, as shown in FIG. A phenomenon of flowing out to the base end portions of the protruding electrodes 5 and 6 through the inner surface occurs. Then, a part of the molten brazing material 8 ′ is formed through the through holes 13 of the terminal electrode members 2 and 3 and the protrusions of the protruding electrodes 5 and 6 from within the annular recess 15 formed at the base ends of the protruding electrodes 5 and 6. Intrusion into the gap with 14 as shown by the arrow by capillarity, and the two are fixed. The remaining portion is stored in the annular recess 15.

In this case, if the recess 15 is not formed, the molten brazing material 8 ′ crawls up along the outer peripheral surface of the protruding electrodes 5 and 6 due to surface tension, and may reach the discharge start surface 12. However, due to the presence of the recess 15, the molten brazing material 8 ′ is stored in the recess 15, and a creeping phenomenon with respect to the projecting electrodes 5, 6 is prevented, and at least the discharge start surface 12 is made the surface of the projecting electrodes 5, 6. Can be left as
That is, the annular recess 15 formed along the circumferential direction of the protruding electrodes 5, 6 reaches the discharge start surface 12 of the molten brazing material 8 ′ that crawls along the outer surface of the protruding electrodes 5, 6. This is a brazing material stopper means for regulating.

The surge absorber 1 manufactured as described above is mounted such that a land formed on a printed circuit board or the like and the outer surfaces of the pair of terminal electrode members 2 and 3 of the surge absorber 1 are fixed by soldering. Used as a structure. When a surge voltage is applied to the surge absorber 1, first, a discharge occurs between the discharge start surfaces 12 in the trigger gap 11 of the protruding electrodes 5 and 6, and argon (Ar) ionized by the discharge in the trigger gap 11 ) Induces a main discharge. By releasing the surge voltage by the main discharge, the electronic device to which the surge absorber 1 is attached can be protected from damage due to the surge voltage.
In this case, since the discharge start surface 12 is secured as the electrode material without the adhesion of the brazing material during the manufacturing process described above, the discharge start voltage can be stabilized in a substantially constant state. is there.

Next, the surge absorber of the reference technique 1 according to the present invention will be described with reference to FIG. In the following description, the same reference numerals are given to the components described in the first embodiment, and the description thereof will be omitted.
The surge absorber 21 of the reference technique 1 is different from the first embodiment in that the recess 22 as the brazing material stopper means in each of the protruding electrodes 5 and 6 has the length of the protruding electrodes 5 and 6 as shown in FIG. It is a point formed at an intermediate position.

According to this surge absorber 21, the molten brazing material that has flowed to the base ends of the protruding electrodes 5 and 6 during the manufacturing process is the same as that of the first embodiment. Part of the member 2 and 3 enters the gap between the through-hole 13 and the remaining part passes along the outer peripheral surface of the protruding electrodes 5 and 6 and the upper side is low, but the length of the protruding electrodes 5 and 6 is It is stored in an annular recess 21 formed at an intermediate position, and further scooping up is restricted so that it does not reach the discharge start surface 12.
The concave portion 21 is formed in the middle of the length of the protruding electrodes 5 and 6 and closer to the base end side than the discharge start surface 12.

4 to 8 show techniques related to the present invention. In these figures, the same reference numerals are given to the components described in the first embodiment, and the description thereof will be omitted. .
The surge absorber 31 of the second embodiment shown in FIG. 4 has a configuration in which the protruding electrodes 5 and 6 are formed in a truncated cone shape, and a concave portion 15 is formed in an annular shape along the circumferential direction at the base end portion thereof. Further, the surge absorber 41 of the reference technique 2 shown in FIG. 5 has a configuration in which a concave portion 15 is formed annularly along the circumferential direction at a midpoint position in the length direction of the truncated conical projecting electrodes 5 and 6. The surge absorber 51 of the reference technique 3 shown in FIG. 6 has a configuration in which the protruding electrodes 5 and 6 are formed in a substantially truncated cone shape, but a concave portion 15 directed in the protruding direction is formed annularly along the circumferential direction at the tip portion. It is.
In any technique , the molten brazing material can be stored in the recess 15 as the brazing material stopper means, and adhesion to the discharge start surface 12 can be prevented.

On the other hand, in the surge absorber 61 of the reference technique 4 shown in FIG. 7, the protruding electrodes 5 and 6 are formed in a truncated cone shape, but the recess 15 in the conventional technique is an annular shape along the circumferential direction. On the other hand, a plurality of groove-like recesses 62 along the length direction are formed at intervals in the circumferential direction. Further, the surge absorber 71 of the reference technique 5 shown in FIG. 8 has a configuration in which a concave portion 72 is formed in a spiral groove shape on the outer peripheral surface of the cone of the frustoconical protruding electrodes 5 and 6.

FIG. 9 shows a surge absorber according to Reference Technique 6. In this surge absorber 81, the inner surface of the pair of terminal electrode members 2 and 3 extends in a spiral toward the other terminal electrode members 2 and 3. The bent protruding electrodes 82 and 83 are fixed. These protruding electrodes 82 and 83 have a discharge start surface 12 at a length within a predetermined range at their tips.
The surge absorber 81 configured in this way is not configured to have a recess for storing the brazing material as in the conventional technologies , and the protruding electrodes 82 and 83 are spirally bent in the case of FIG. 9. As a result, the length thereof is significantly increased with respect to the linear distance along the axial direction of the insulating tube 4 from the surface of the terminal electrode members 2 and 3 to the discharge start surface 12. Even if scooping up occurs, arrival at the discharge start surface 12 is suppressed.

  As the bent shape of the protruding electrodes 82 and 83, in addition to the helical shape of the example of FIG. 9, a crank shape or the like can be adopted, and thus the protruding electrode is bent and formed into a helical shape or a crank shape, By forming the length larger than the linear distance along the axial direction of the insulating tube 4 from the surface of the terminal electrode members 2 and 3 to the discharge start surface 12, the molten brazing material creeps up to the discharge start surface 12. In the present invention, the regulating structure is also used as the brazing material stopper means.

Further, FIG. 10 shows a surge absorber of the reference technique 7, also in the surge absorber 91, instead of storing the molten brazing material into the recess as the first embodiment, the start discharge projection electrodes 92 and 93 A barrier film 94 having low wettability with respect to the brazing material 8 is formed at the tip including the surface 12. The barrier film 94 is formed by coating the surface of the protruding electrodes 92 and 93 with a metal such as stainless steel (SUS) by sputtering or CVD.
In the surge absorber 91 of this reference technique 7 , even if the molten brazing material creeps up on the outer surfaces of the protruding electrodes 92, 93, further scooping is suppressed at the barrier film 94, and the discharge start surface Thus, the barrier film 94 is also used as the brazing material stopper means in the present invention.

In addition, this invention is not limited to the thing of each embodiment shown above, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, the pair of terminal electrode members may be Cu or Ni-based alloys in addition to the metals mentioned in the embodiment, and the protruding electrodes may be Fe, Cu, Mo, Mn in addition to Ti, Ni, and Fe—Ni alloys. , W, Ag, Al, Pd, Pt, or an alloy of two or more of these may be used. In this case , a conductive film such as SnO ₂ , SiC, ITO, TiC, TiCN, BaAl ₄ or the like may be formed on the surface of the protruding electrode except for the barrier film of Reference Technique 7 by sputtering or the like.

Further, the metallized layers 7 on both end surfaces of the insulating tube 4 may be Ag, Cu, Au, Mo—Mn, or may be sealed only with the brazing material 8 made of active metal without using the metallized layer 7. Good.
Furthermore, the pair of protruding electrodes may have a columnar shape such as a cylinder or a prism, a conical shape, a triangular pyramid shape, or the like that reduces the inner diameter of the outer periphery toward the tip, and a metal thin plate shape that is manufactured by punching or the like Is also possible.
Further, the protruding electrode and the terminal electrode member are fixed by brazing after press-fitting, but welding or the like may be used.

It is a longitudinal section showing a surge absorber concerning a 1st embodiment of the present invention. It is sectional drawing which expands and shows the adhering part of the protrusion electrode and terminal electrode member in FIG. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 1 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 2 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 3 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 4 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 5 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on the reference technique 6 of this invention. It is a longitudinal cross-sectional view which shows the surge absorber which concerns on this invention reference technique 7 .

1, 2, 31, 41, 51, 61, 71, 81, 91 ... Surge absorber 2, 3 ... Terminal electrode member 4 ... Insulating tube 5, 6, 82, 83, 92, 93 ... Projecting electrode 7 ... Metallized layer DESCRIPTION OF SYMBOLS 8 ... Brazing material 8 '... Molten brazing material 9 ... Internal space 11 ... Micro gap 12 ... Discharge start surface 13 ... Through-hole 14 ... Protrusion 15, 62, 72 ... Recessed part (brazing material stopper means) 94 ... Barrier film (brazing material) Stopper means)

Claims (2)

An insulating tube surrounding the discharge space is fixed between the pair of terminal electrode members by brazing, and projecting electrodes projecting toward the other terminal electrode member on the inner surfaces of the pair of terminal electrode members, respectively It is fixed by being inserted the small diameter projection into the hole of the terminal electrode member than the projecting electrodes formed on the proximal end of the protruding electrode, and the inner surface of the terminal electrode member and the base end of the protruding electrode In the meantime, a brazing material stopper means comprising a recess capable of storing the brazing material, which regulates the creeping of the molten brazing material to the discharge start surface of the protruding electrode, is formed in a groove shape along the circumferential direction. Surge absorber characterized by 2. The surge absorber according to claim 1 , wherein the terminal electrode member is formed in a plane between a fixing portion with the insulating tube and a fixing portion of the protruding electrode.

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