JP4449806B2 - Surge absorber and manufacturing method thereof - Google Patents

Description

  The present invention relates to a surge absorber used for protecting various devices from surges and preventing accidents, and a method for manufacturing the same.

  Abnormal currents (surge currents) and abnormal voltages (surge voltages) such as lightning surges and static electricity in parts where electronic devices for communication devices such as telephones, facsimiles and modems are connected to communication lines, power lines, antennas or CRT drive circuits A surge absorber is connected to a portion that is easily subjected to electric shock due to the electrical shock in order to prevent destruction due to abnormal damage due to thermal damage or ignition of an electronic device or a printed circuit board on which the device is mounted.

  Conventionally, for example, a surge absorber using a surge absorbing element having a micro gap has been proposed. In this surge absorber, a so-called microgap is formed on the peripheral surface of a cylindrical ceramic member coated with a conductive film, and a surge absorbing element having a pair of cap electrodes at both ends of the ceramic member is placed in a glass tube together with a sealing gas. It is a discharge type surge absorber in which sealed electrodes having lead wires at both ends of a cylindrical glass tube are sealed by high temperature heating.

Also in such a discharge type surge absorber, a surge absorber is proposed in which the manufacturing cost is reduced by reducing the number of parts (see, for example, Patent Document 1). This surge absorber includes an insulating tube provided on the inner peripheral surface with a conductive coating dividedly formed through a discharge gap, and a seal provided on both ends of the insulating tube and electrically connected to the conductive coating. And a stop electrode.
JP-A-7-22152

  However, the following problems remain in the conventional surge absorber. That is, in the above-described conventional surge absorber, a discharge gap is formed by irradiating the conductive film with laser light transmitted through the insulating tube from the outside of the insulating tube after the conductive film is formed on the inner peripheral surface of the insulating tube. Is forming. Here, as a method of forming the conductive film only on the inner peripheral surface of the insulating tube, a conductive film is formed on the inner and outer peripheral surface of the insulating tube by sputtering or the like, and the insulating tube is formed using diluted hydrochloric acid or the like. This is done by removing the conductive film adhering to the outer peripheral surface. Therefore, there are problems that the manufacturing is complicated and the manufacturing cost is increased.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a surge absorber capable of reducing the number of parts to be used and reducing the manufacturing cost and the manufacturing method thereof.

The present invention employs the following configuration in order to solve the above problems. That is, the surge absorber according to the present invention is made of metal and has a pair of linear trigger electrodes whose ends are opposed to each other via a discharge gap, and is made of metal and connected to the base end of the trigger electrode. A pair of main discharge electrodes, and an insulating tube that encloses a main discharge surface, which is a surface of the pair of trigger electrodes and the pair of main discharge electrodes, facing each other together with a sealing gas are provided inside.

According to the present invention, an abnormal current and an abnormal voltage such as a surge entering from the outside are absorbed by performing a main discharge between the main discharge surfaces of the pair of main discharge electrodes using a discharge in the discharge gap as a trigger. At this time, since the pair of trigger electrodes are linear electrodes, the space occupied by the trigger electrode is reduced in the space formed inside the insulating tube enclosing the trigger electrode. Thereby, a large discharge space for the main discharge performed between the main discharge surfaces can be provided. Therefore, it is possible to reduce the size of the surge absorber and improve the surge resistance (electrostatic resistance).
In addition, since the trigger electrode is formed by a pair of linear electrodes, the number of parts to be used can be reduced and the manufacturing cost can be reduced.

In the surge absorber of the present invention, it is preferable that the outer peripheral surfaces of the pair of main discharge electrodes are in contact with the inner peripheral surface of the insulating tube.
According to the present invention, the pair of trigger electrodes and the main discharge electrode can be easily positioned with respect to the insulating tube. Further, the surge absorber can be further reduced in size in a state where a sufficient discharge space for main discharge is secured.

In the surge absorber of the present invention, it is preferable that a laser capable of dividing the trigger electrode can pass through the insulating tube.
According to the present invention, after the trigger electrode connection body to which the pair of trigger electrodes are connected is enclosed in the insulating tube, the trigger electrode connection body is irradiated with laser from the outside of the insulating tube, and the discharge gap and A pair of trigger electrodes is formed.

A method of manufacturing a surge absorber of the present invention is formed of a metal, a pair of main discharge electrodes made of a metal is a trigger electrode connecting body connected linear across, together with the sealing gas in the insulating tube A sealing step of sealing, and by irradiating the trigger electrode connector from the outside of the insulating tube with laser light to divide the discharge gap and the base end of the pair of main discharge electrodes, respectively. A splitting step of simultaneously forming a pair of trigger electrodes whose tips are opposed to each other via the discharge gap.

  According to the present invention, a linear trigger electrode connection body having main discharge electrodes connected to both ends is sealed together with a sealing gas in an insulating tube, and then laser light is irradiated to a predetermined position of the trigger electrode connection body. To form a discharge gap. As a result, a pair of trigger electrodes is formed in which the base ends are connected to each of the pair of main discharge electrodes and the tip ends are opposed to each other via the discharge gap. By doing so, it is easier to position the trigger electrode in the insulating tube than to enclose the pair of trigger electrodes formed in advance in a state of being opposed to each other through the discharge gap in the insulating tube. Become. Therefore, it becomes easy to manufacture a surge absorber with a small manufacturing error. Similarly to the above, since the trigger electrode is formed by a pair of linear electrodes, the size can be reduced, the number of parts to be used can be reduced, and the manufacturing cost can be reduced.

In the method of manufacturing a surge absorber according to the present invention, it is preferable to irradiate a YAG laser or an ultraviolet laser in the dividing step.
According to the present invention, in the dividing step, the trigger electrode assembly is irradiated with a YAG laser or an ultraviolet laser that can pass through the insulating tube to form a discharge gap and a pair of trigger electrodes.

According to the surge absorber of the present invention, since the trigger electrode is formed by a pair of linear electrodes, the space occupied by the trigger electrode with respect to the discharge space can be reduced, and the surge absorber can be miniaturized and the surge resistance can be improved. it can. Further, the number of parts to be used can be reduced and the manufacturing cost can be reduced.
Further, according to the surge absorber manufacturing method of the present invention, since the discharge gap is formed after the trigger electrode connector and the main discharge electrode are sealed in the glass tube, the trigger electrode can be easily positioned. Therefore, it becomes easy to manufacture a surge absorber with a small manufacturing error.

Hereinafter, an embodiment of a surge absorber and a manufacturing method according to the present invention will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the surge absorber 1 according to the present embodiment is a discharge type surge absorber using a micro gap, and a pair of trigger electrodes 3 disposed to face each other via a discharge gap 2, and the trigger electrodes 3. A pair of main discharge electrodes 4 that are disposed opposite to each other and contact the trigger electrode 3, and a glass tube (insulating tube) 6 that is disposed at both ends and sealed together with the sealing gas 5. It has.

The trigger electrode 3 is formed of a copper-clad steel wire (hereinafter referred to as CP wire), and the base end is connected to the main discharge electrode 4. And the front-end | tip of the trigger electrode 3 is mutually opposingly arranged through the discharge gap 2. As shown in FIG.
In order to match the thermal expansion coefficient with the glass tube 6, the main discharge electrode 4 is formed of an iron nickel copper wire in which the surface of an Fe (iron) -Ni (nickel) alloy wire is coated with copper oxide, and has a disk shape. ing. The trigger electrode 3 is welded to one surface of the main discharge electrode 4, and the lead wire 7 is welded to the other surface. The lead wire 7 is formed of a CP wire, like the trigger electrode 3. The opposing surfaces of the pair of main discharge electrodes 4 are main discharge surfaces 4 </ b> A for performing main discharge between the main discharge electrodes 4.
As shown in FIG. 2, the pair of trigger electrodes 3, the pair of main discharge electrodes 4, and the pair of lead wires 7 are welded to each other to integrate the trigger electrode connector 9 of the integrated slug lead 8. The discharge gap 2 is formed by dividing the center. Here, the discharge gap 2 is formed by dividing the trigger electrode connector 9 by irradiating the center of the trigger electrode connector 9 with a laser beam from a YAG (Yttrium Aluminum Garnet) laser. The irradiation position of the laser light is not limited to the central portion of the trigger electrode connecting body 9 and may be near the central portion. The trigger electrode 3 and the lead wire 7 may be made of iron-nickel copper wire, like the main discharge electrode 4.

The glass tube 6 is made of a diode glass such as K ₂ O · PbO · SiO ₂ glass or Na ₂ O · K ₂ O · PbO · SiO ₂ glass that transmits laser light from a YAG laser. It is cylindrical. Further, the outer peripheral surface of the main discharge electrode 4 is welded to the inner peripheral surface of the glass tube 6 in the vicinity of both ends of the glass tube 6. Here, since the surface of the main discharge electrode 4 is covered with copper oxide, the wettability with glass is good. Therefore, in the sealing step described later, the weld between the inner peripheral surface of the glass tube 6 and the outer peripheral surface of the main discharge electrode 4 becomes strong, and sealing can be performed more reliably.
The sealing gas 5 is a gas whose composition is adjusted so that electrical characteristics such as a discharge start voltage have a desired value, and is composed of, for example, Ar (argon).

Next, a method for manufacturing the surge absorber 1 of the present embodiment having the above configuration will be described.
The manufacturing method of the surge absorber in the present embodiment includes an integrated slag lead forming step, an enclosing step, and a dividing step.
First, an integrated slag lead forming step is performed. In this integrated slag lead forming step, first, both ends of the trigger electrode connector 9 are welded to one surface of the pair of main discharge electrodes 4 respectively. Then, the pair of lead wires 7 are welded to the other surfaces of the pair of main discharge electrodes 4, respectively. Thereby, the trigger electrode connector 9, the pair of main discharge electrodes 4, and the pair of lead wires 7 are integrated to form an integrated slug lead 8 shown in FIG.

  Next, an encapsulation process is performed. In this sealing step, the glass tube 6 and the integrated slag lead 8 are welded using the carbon heater 10 in the atmosphere of the sealing gas 5. As shown in FIG. 3A, the carbon heater 10 includes an upper jig 11 and a lower jig 12 made of carbon. The upper jig 11 and the lower jig 12 are formed with work holes 11A and 12A for receiving the glass tube 6 and the integrated slug lead 8, respectively. First, the glass tube 6 is placed in the workpiece hole 12 </ b> A, and then the integrated slug lead 8 is placed so as to be inserted into the glass tube 6. In the atmosphere of the sealing gas 5, the upper jig 11 and the lower jig 12 are heated to weld the outer peripheral surface of the main discharge electrode 4 and the inner peripheral surfaces near both ends of the glass tube 6. As a result, the trigger electrode connector 9 and the main discharge surfaces of the pair of main discharge electrodes 4 are sealed together with the sealing gas 5 in the glass tube 6.

Finally, a dividing step is performed. In this dividing step, as shown in FIG. 3B, the YAG laser 13 is used to irradiate the center of the trigger electrode connector 9 with laser light. The laser beam from the YAG laser 13 has a wavelength of 1064 nm, can be transmitted through the glass tube 6 and is absorbed by the trigger electrode connection body 9, so that the trigger electrode connection body 9 is divided to form the discharge gap 2 and the pair of laser beams. The trigger electrode 3 is formed. Here, when the trigger electrode connector 9 is irradiated with a laser beam and divided, the glass tube 6 enclosing the integrated slag lead 8 may be irradiated with the laser beam while rotating around the axis. The laser beam may be irradiated without rotating around. The surge absorber 1 is manufactured as described above.
The surge absorber 1 manufactured in this manner is used by, for example, bonding and fixing a printed circuit board and a pair of lead wires 7 with solder. Then, an abnormal voltage such as a surge entering from the outside is absorbed by performing a main discharge between the main discharge surfaces 4A of the pair of main discharge electrodes 4 using the discharge in the discharge gap 2 as a trigger.

  According to the surge absorber 1 configured as described above, since the pair of trigger electrodes 3 are formed of linear electrodes, the space occupied by the pair of trigger electrodes 3 with respect to the discharge space can be reduced. Thereby, size reduction of a surge absorber and improvement of surge tolerance can be achieved. In addition, the manufacturing cost can be reduced by reducing the number of parts.

In addition, according to the above-described surge absorber manufacturing method, the discharge gap 2 is formed after the trigger electrode 3 and the main discharge electrode 4 are sealed in the glass tube 6, so that the trigger electrode 3 can be easily positioned. Therefore, the opposing position of the tip of the trigger electrode 3 becomes difficult to shift, and a surge absorber with a small manufacturing error can be manufactured stably.
Here, in general, an IR check test is performed on the manufactured surge absorber in order to confirm that the discharge gap is reliably formed and is open between the pair of main discharge electrodes. This IR check test is a test in which a voltage is applied between a pair of main discharge electrodes and the amount of current flowing through the surge absorber at that time is measured. When the measured resistance value is larger than the predetermined value, it is determined that the conductive film is divided by the discharge gap and is open between the pair of sealing electrodes. Further, when the measured resistance value is smaller than a predetermined value, it is determined that a short state is established between the pair of sealing electrodes due to, for example, foreign matter existing in the discharge gap. In the method of manufacturing a surge absorber according to the present invention, the discharge gap 2 and the pair of trigger electrodes 3 are formed by dividing the trigger electrode connection body 9 by irradiating the trigger electrode connection body 9 with laser light. For this reason, the IR check test can be omitted, and the manufacturing procedure of the surge absorber can be simplified.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above embodiment, the peripheral surface of the main discharge electrode and the inner peripheral surface of the glass tube are welded, but a surge absorber 20 having a configuration as shown in FIG. 4 may be used. The surge absorber 1 has a configuration in which openings at both ends of the glass tube 21 are welded so that the lead wires 7 protrude from both ends of the glass tube 21 in the sealing step.
Moreover, although the lead wire is welded to the other surface of the main discharge electrode, the structure which does not provide a lead wire may be sufficient.

In addition, it is manufactured by forming a discharge gap in the trigger electrode connection body of the integrated slug lead that integrates the trigger electrode connection body, the main discharge electrode, and the lead wire, but the trigger electrode is arranged opposite to the discharge gap. It only has to be done. That is, it is manufactured by using a pair of integrated trigger electrodes, main discharge electrodes and lead wires, and enclosing them in a glass tube in a state where the tips of the respective trigger electrodes are arranged to face each other via a discharge gap. May be.
Moreover, although Ar is used as the sealing gas, other gases may be appropriately used according to the discharge characteristics of the surge absorber. Here, examples of applicable sealing gas include N ₂ , Ne, He, Xe, Kr, H ₂ , SF ₆ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , and CO ₂ . Moreover, you may use the mixed gas selected suitably among these, adding Ar.
Moreover, although the glass tube comprised with the diode glass is used as an insulating tube, it should just be comprised with the material which can permeate | transmit the laser which can cut | disconnect a trigger electrode assembly. For example, you may be comprised with the glass tube using glass materials, such as lead glass and soda-lime glass. Furthermore, you may be comprised by the ceramic pipe | tube comprised with ceramic materials, such as PLZT (lead lanthanum dope lead zirconate titanate) and transparent alumina.
Moreover, although CP wire and iron nickel copper wire are used as the integral slag lead, other materials may be used.
In the dividing step, a discharge gap is formed by irradiating a laser beam from a YAG laser. However, the wavelength of light that can be transmitted by the material used for the trigger electrode and is absorbed by the material used for the trigger electrode. Any laser beam may be used as long as it is irradiated, and for example, another laser such as an ultraviolet laser may be used.

It is an axial sectional view showing a surge absorber in one embodiment of the present invention. It is an axial sectional view showing an integrated slug lead. It is explanatory drawing which shows the manufacturing process of the surge absorber of FIG. It is an axial sectional view showing another surge absorber to which the present invention is applicable.

Explanation of symbols

1, 20 Surge absorber 2 Discharge gap 3 Trigger electrode 4 Main discharge electrode 4A Main discharge surface 5 Sealing gas 6, 21 Glass tube (insulating tube)
9 Trigger electrode connector 13 YAG laser

Claims (5)

Is formed of a metal, a pair of linear trigger electrodes are oppositely arranged with an tip discharge gap, is formed of a metal, a pair of main discharge electrodes connected respectively to the proximal end of the trigger electrode, the internal A surge absorber comprising: an insulating tube that encloses a main discharge surface that is a surface of the pair of trigger electrodes and the pair of main discharge electrodes facing each other together with a sealing gas.   The surge absorber according to claim 1, wherein the outer peripheral surfaces of the pair of main discharge electrodes are in contact with the inner peripheral surface of the insulating tube.   The surge absorber according to claim 1 or 2, wherein the insulating tube is capable of transmitting a laser capable of dividing the trigger electrode. Formed of metal, and enclosing step of the pair formed by the metal of the main discharge electrodes is connected to a linear trigger electrode connecting body, enclosed with sealing gas on the insulating tube at both ends,
By irradiating the trigger electrode connecting body with laser light from the outside of the insulating tube and dividing it, a discharge gap and a base end are connected to each of the pair of main discharge electrodes, and a tip is connected to the discharge gap. And a splitting step of simultaneously forming a pair of trigger electrodes arranged opposite to each other via a gap.   The method of manufacturing a surge absorber according to claim 4, wherein YAG laser or ultraviolet laser is irradiated in the dividing step.

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