JP2001135453A - Surface mounting type surge absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mounting type surge absorber which can be manufactured easily and economically, even if it is a surge absorber equipped at its both ends with header electrodes for surface mounting with complex configuration. SOLUTION: A surge absorbing element 15 comprising an electro-conductive membrane 30 which has a discharge trigger gap 31 on the surface of an insulator 20 is housed in a tube 40 filled with inert gas, the terminal of the tube 40 is sealed with sealing electrodes 50, 50, and the sealing electrodes 50, 50 are connected to the terminal of the surge absorbing element 15. By installing header electrodes for planar installation 70, 70 on the external face of the sealing electrodes 50, 50, a surface mounting type surge absorber 10 is composed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surge absorber, and more particularly, to a surface mount type surge absorber suitable for surface mounting.

[0002]

2. Description of the Related Art Conventionally, there is a risk that a surge current due to lightning or the like may enter an electronic device and destroy it. For this reason, a surge absorber is attached to release the surge current by discharging, thereby protecting the electronic device.

In this surge absorber, as shown in FIG. 4, a surge absorbing element 100 is accommodated in a glass tube 110 filled with an inert gas, and both ends of the tube 110 are sealed with a sealing electrode 12.
0, 120 and sealing electrodes 120, 120
Terminal electrodes 1 attached to both ends of surge absorbing element 100
08, 108.

The surge absorbing element 100 is a rod-shaped insulator 1
01, a conductive film 103 is formed on the surface thereof, and a discharge trigger gap 105 for dividing the conductive film 103 in the center thereof.
And cap-shaped terminal electrodes 108, 1 at both ends.
08 is attached.

When a surge current is applied between the sealing electrodes 120, 120, first, the discharge trigger gap 105
, A discharge occurs to break the insulation in the tube 110, and a discharge starts between the terminal electrodes 108, 108.

In order to mount this surge absorber directly on a circuit board of an electronic device, it is necessary to use both sealing electrodes 1.
A method in which the electrodes 20 and 120 are formed to protrude to the outside of the glass tube 110, the protruding portions are used as surface mounting electrodes, and the double-sided mounting electrodes are soldered to a pattern on the substrate is considered.

However, in the case of the surge absorber, the sealing electrode 120 needs to be formed of a dumet wire (copper-coated iron-nickel alloy wire) which is a metal compatible with the glass tube 110. This dumet wire has a double structure. This is a disadvantage that it is difficult to perform complicated processing because it is a metal. If the sealing electrode 120 and the surface-mounting electrode are to be integrally manufactured, the structure becomes complicated. There was a problem that it is.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide, for example, a surge absorber having surface-mounting electrodes of a complicated shape for surface mounting attached to both ends thereof. Another object of the present invention is to provide a surface mount type surge absorber that can be manufactured easily and at low cost.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method of forming a surge absorbing element having a conductive film having a discharge trigger gap on the surface of an insulator in a tube filled with an inert gas. And an end of the tube is sealed with a sealing electrode, and the sealing electrode is connected to an end of the surge absorbing element. The surface mount type surge absorber was constructed by attaching. Here, it is preferable that the surface mounting electrode is attached to the sealing electrode by welding. Preferably, at least one of the surface mounting electrode and the sealing electrode is provided with a projection for welding.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a surface mount type surge absorber 10 according to the present invention, and FIG. 2 is a perspective view. As shown in both figures, the surface mount type surge absorber 10
Forms a conductive film 30 on the surface (peripheral surface) of the insulator 20 made of a cylindrical ceramic body, and provides a discharge trigger gap 31 for dividing the conductive film 30;
A pair of cap-shaped terminal electrodes 23 are provided at both ends of the insulator 20.
23 to form the surge absorbing element 15,
The surge absorbing element 15 is housed in a glass tube 40 filled with an inert gas such as argon gas, and both ends of the tube 40 are sealed with sealing electrodes 50, 50.
0, 50 are welded (connected) to the terminal electrodes 23, 23.

The sealing electrodes 50, 50 are made of a dumet wire which is a special metal (copper-coated iron-nickel alloy wire) having a high degree of adhesion to glass. The terminal electrodes 23 are made of, for example, stainless steel.

In the present invention, the sealing electrodes 50,
The surface mounting electrodes 70, 70 are connected and integrated to both outer end surfaces of 50 by welding. These surface mounting electrodes 70,
Reference numeral 70 denotes a cylindrical shape in this embodiment, which is made of a low-cost and easy-to-process metal material, for example, stainless steel. The outer diameter of the surface mounting electrodes 70, 70 is
0 is formed larger than the outer diameter. In particular, in this embodiment, the sealing electrodes 50 of the surface mounting electrodes 70, 70,
At the center of the surface on the side connected to 50, projections 71 and 7 for welding are provided.
1 is provided so that the welding energy is concentrated on these projections 71 and 71, and the welding is reliably performed on the sealing electrodes 50 and 50.

The surface mount type surge absorber 10
In order to manufacture the device, the surge absorbing element 15 is housed in the tube 40 in an atmosphere of an inert gas such as an argon gas, and the sealing electrodes 50, 50 are inserted into both ends of the tube 40 to form the sealing electrodes 50, 50.
Is welded to the terminal electrodes 23, 23, and the tube 40 is heated (for example, 700 ° C.) to soften and shrink, whereby both ends of the tube 40 are welded to the sealing electrodes 50, 50 to seal the inside thereof. I do. As a result, the surge absorbing element 15 is completely shut off from the outside and is sealed in an inert gas.

Next, the surface mounting electrodes 70, 70 are attached to the outer surfaces of the sealing electrodes 50, 50 by welding. This welding is performed by a normal welding machine (not shown). At this time, the tube 40 and the electrodes 70 for two-sided mounting can be welded in a state where both are securely held by a jig. Therefore, the surface mounting electrodes 70, 70 can be welded to the sealing electrodes 50, 50 at accurate positions. In this embodiment, the surface mounting electrodes 70, 70 are not necessary since they are circular. However, when the outer peripheral shape is non-circular, the position in the rotational direction can be set accurately and reliably.

Particularly, in this embodiment, since the projections 71, 71 are provided on the double-sided mounting electrodes 70, 70, the energy at the time of welding is concentrated on this portion, and the double-sided mounting electrodes 70, 70 are more accurate. It is reliably welded to the central portions of both sealing electrodes 50,50.

The surface mount type surge absorber 10
Are placed on the substrate in a horizontal position, and the surface mounting electrodes 7
0, 70 are directly soldered to the pattern of the substrate.

When a surge current is applied between the surface mounting electrodes 70, 70, a discharge is first generated in the discharge trigger gap 31 to break the insulation in the tube 40, and a discharge is caused between the two terminal electrodes 23, 23. Start.

FIG. 3 is a perspective view showing a surface mount type surge absorber 10-2 according to another embodiment of the present invention. In the figure, the same parts as those of the above embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.

This embodiment is different from the above embodiment only in the outer peripheral shape of the surface mounting electrodes 70-2, 70-2. That is, the outer shape of the surface mounting electrodes 70-2, 70-2 is formed in a regular octagonal shape. With this configuration, when the surface mount type surge absorber 10-2 is mounted on a substrate, it does not roll and stops at the mounting position without fail and has stability. Since the contact is made, the electrical connection is also ensured.

Since the surface mounting electrodes 70-2, 70-2 and the sealing electrodes 50, 50 can be welded by a normal welding machine (not shown), the surface mounting electrodes 70-2, 70
No. 0-2 can be welded to the sealing electrodes 50, 50 at accurate positions, and even if the outer peripheral shape is non-circular, the position in the rotational direction can be set accurately and reliably, and can be easily mounted symmetrically. I can do it.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims and the technical idea described in the specification and the drawings. Is possible. It should be noted that any shape or material not directly described in the specification and the drawings is within the scope of the technical idea of the present invention as long as the effects and effects of the present invention are exhibited.

For example, instead of providing a projection for welding on the surface mounting electrode, a projection for welding may be provided on the sealing electrode.
Also, this projection may be provided on both. Further, the projection for welding need not always be provided at the center position of the surface mounting electrode or the sealing electrode, and may be provided at another position or at a plurality of positions. In short, it may be provided on at least one of the surfaces to which both the surface mounting electrode and the sealing electrode are welded.

The shape and structure of the surge absorbing element 15 can be variously modified. In short, any shape and structure may be used as long as the end of the tube is sealed with the sealing electrode and the sealing electrode is connected to the end of the surge absorbing element.

In the above embodiment, the surface mounting electrode 70-
Although 2 is an example of an octagon, other various polygons such as a square and a pentagon may be used. Also, it need not be a regular polygon.

[0025]

As described in detail above, the present invention has the following excellent effects. Since the sealing electrode and the surface mounting electrode are separated and configured as separate members, even a surface mounting electrode with a complicated shape that is stable when mounted on the surface can be easily manufactured using inexpensive materials. it can.

Since the surface mounting electrode is attached to the sealing electrode by welding, positioning is easy and reliable, and even a polygonal surface mounting electrode can be easily assembled symmetrically.

In particular, when a projection for welding is provided on at least one of the surface mounting electrode and the sealing electrode, the surface mounting electrode can be more accurately and reliably welded to the sealing electrode.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a surface mount type surge absorber 10 according to the present invention.

FIG. 2 is a perspective view showing the surface mount type surge absorber 10;

FIG. 3 is a perspective view showing a surface mount type surge absorber 10-2 according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a conventional surge absorber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Surface mount type surge absorber 15 Surge absorption element 20 Insulator 23 Terminal electrode 30 Conductive film 31 Discharge trigger gap 40 Tube 50 Sealing electrode 70 Surface mount electrode 71 Projection 10-2 Surface mount type surge absorber 70-2 Surface mount Electrode

Claims (3)

[Claims] 1. A surge absorbing element having a conductive film having a discharge trigger gap formed on the surface of an insulator is housed in a tube filled with an inert gas, and the end of the tube is sealed with a sealing electrode. A surface-mount type surge absorber comprising a sealing electrode connected to an end of a surge absorbing element and a surface-mounting electrode attached to an outer surface of the sealing electrode. 2. The surface mount type surge absorber according to claim 1, wherein the surface mount electrode is attached to the sealing electrode by welding. 3. The surface-mounted surge absorber according to claim 2, wherein at least one of the surface-mounted electrode and the sealing electrode is provided with a projection for welding.