JPS6334434Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a unit that combines various safety elements used in communication protectors, and uses an adhesive to bond a button-shaped gas-filled discharge tube or a semiconductor safety element to a semiconductor safety element. However, the adhesive layer is provided with electrically conductive holes that cause local dielectric breakdown.

In general, communication safety devices are broadly divided into those that interrupt current, such as fuses, and those that release voltage to earth, such as button-type gas-filled discharge tubes and semiconductor safety devices. Configure the element unit. When a button-shaped gas-filled discharge tube and a semiconductor safety element, such as a thermistor, are combined as this communication safety element unit, the heat generated when the gas-filled discharge tube discharges due to an interference wave is transferred to the thermistor.
By increasing the resistance value of the thermistor and eliminating the delay of the thermistor, it is possible to exhibit high safety performance. In addition, the discharge heat of the gas-filled discharge tube can be quickly absorbed by the thermistor, which not only improves the discharge characteristics of the gas-filled discharge tube, but also makes it possible to downsize the safety circuit and simplify installation into equipment. It has features that can improve work efficiency. From a similar point of view, a unit can be constructed by combining other communication security elements.

Conventionally, a gas-filled discharge tube and a thermistor have been housed in a case and wired within the case to form a safety element unit. This not only complicates the work process and increases costs, but also prevents miniaturization, and has the disadvantage that the discharge heat of the discharge tube cannot be dissipated, resulting in a deterioration of the discharge characteristics.

In order to eliminate the above-mentioned drawbacks, it has been proposed to directly solder and join the electrode surface of the thermistor to the metal electrode surface of the gas-filled discharge tube without using a case. However, due to the extreme difference in coefficient of thermal expansion between the metal electrode and the thermistor, which is a sintered body, it is easy to peel off from the soldered part after discharge heat is generated, making it impractical. Furthermore, depending on the skill of the soldering technique, the electrode surface of the thermistor may be damaged or the lead wire portion may be melted and peeled off. Furthermore, not only does solder diffusion occur due to differences in the base materials of the two metal electrodes being joined, but also an ohmic phenomenon occurs due to contact between the metal and the sintered semiconductor, which impairs the original electrical characteristics. Ta. The Ohmic phenomenon had to be solved by plating the surface of the metal electrode with a metal with a large work function, such as gallium.

Therefore, in order to achieve a strong bond, it is currently necessary to electrolessly plate or metalize the electrode surface with nickel or the like for bonding. Similar problems occurred with safety element units that were combined with other than those mentioned above.

The present invention is based on the result of repeated research to eliminate the above-mentioned drawbacks and the finding that using adhesive instead of solder can overcome the difference in coefficient of thermal expansion and create a strong bond. To provide a communication security element unit that can be firmly bonded without using structural pressure means such as a case, and that does not impair electrical characteristics by forming conductive holes in the adhesive layer in advance. That is. Hereinafter, the present invention will be explained based on an illustrative embodiment.

FIG. 1 is a front view showing a unit of a button-shaped gas-filled discharge tube and a semiconductor safety device, and FIG. 2 is a plan view of the semiconductor safety device from an adhesive layer. In the figure, A is a three-electrode button-shaped gas-filled discharge tube. Discharge tube A is made up of an insulating tube 1 whose openings at both ends are sealed with metal electrodes 2 and 3, and gas is sealed inside. The electrode 5 is a lead wire connected to the intermediate electrode 4. S is a thermistor as a semiconductor safety element, 6 and 7 are its electrodes, 8 is a lead wire connected to the electrode 6, and 9 is a lead wire connected to the electrode 7.

The thermistor S has a larger diameter than the discharge tube A, and has a structure in which a non-adhesive surface area 10 is formed on the electrode 7, and a lead wire 9 is connected to the non-adhesive surface area 10 to achieve planar adhesion with the discharge tube electrodes 2 and 3. do. The non-adhesive surface area 10 may be constructed by slightly shifting the thermistor S to the side.

Reference numeral 11 denotes an adhesive layer for bonding the electrodes 7, 7 of the thermistors S, S to the surfaces of the electrodes 2, 3 of the discharge tube A in an insulating state. Adhesives here refer to natural polymer adhesives such as starch, excluding metal bonding materials such as solder, as well as semi-synthetic polymer adhesives and synthetic polymer adhesives, and are heat-resistant and do not deteriorate due to discharge heat. means adhesive. Since the adhesive layer 11 has insulating properties,
After adhesion, a high voltage is applied to the adhesive layer 11 to locally cause dielectric breakdown that causes carbonization, and this carbonized portion is formed into a conductive hole 12 with a voltage higher than a certain level. In this case, the adhesive force acts in areas other than the conductive hole 12 where the dielectric breakdown occurred, so strong adhesion is not affected. Moreover, the adhesive layer 11 can be sufficiently spread over the entire plane contact area. Note that it is also possible to use a conductive adhesive as the adhesive.

By constructing the communication security element unit using adhesive, it can be suitably implemented, for example, in a security circuit for a switchboard such as a telephone set. That is, the lead wires 8 and 8 can be connected to the inner wire sides I ₁ and I ₂ and the lead wires 9 and 9 can be connected to the outer wire sides L ₁ and L 2, respectively, without requiring a conventional mounting block for the discharge tube or the _like . A safety circuit can be formed by simply connecting the lead wire 5 to the ground side E, and the disturbance wave is conducted to the metal electrode 2 or 3 of the discharge tube A through the conductive hole 12, causing the discharge tube A to discharge. Differences in thermal expansion coefficients are buffered by the insulating properties of the adhesive layer 11. Although not shown, the above unit can be used to bond a varistor and a gas-filled discharge tube.
Connect in series to form a safety circuit for preventing follow-on current.
Incidentally, the present invention can also be applied to a bipolar gas-filled discharge tube.

FIG. 3 is a front view showing a unit in which semiconductor safety devices are bonded together. In the figure, V is a varistor as a semiconductor element, 13 and 14 are its electrodes, and 1
5 is a lead wire connected to electrode 13, 16 is electrode 1
4, 14, and is a lead wire connected to the electrodes 14, 14.
14 is bonded using an adhesive, and the adhesive layer 11
A conductive hole 12 is provided in the conductive hole 12 . According to this, not only can a multi-pole varistor unit be constructed, but also it is possible to arbitrarily combine varistors V with different characteristics without changing the electrical characteristics. Can be implemented in circuits. It also has the advantage of being downsized and improving workability. Although not shown, the varistor V and thermistor S may be bonded together to form a protector circuit.

Accordingly, the present invention has the following effects.

Since the adhesive layer acts as a buffer zone, strong adhesion can be achieved even if the thermal expansion coefficients of the bonded parts are different. In particular, peeling from the bonded parts due to heat generation of the safety element can be completely prevented, making practical use possible.

Communication security element units can be manufactured using adhesives, and not only can they be made smaller without using structural pressure means such as cases, but bonding is extremely easy compared to conventional methods, simplifying the work process. Can be manufactured cheaply.

Since the electrode surface of the element is bonded with adhesive, the electrode surface will not be damaged or the electrical characteristics will change, and safety performance can be improved by mutual thermal reaction through the adhesive layer. .

Since the conductive holes are locally broken by applying a constant voltage to the adhesive layer, the adhesive layer can conduct only voltages higher than the constant voltage, and the range of implementation can be expanded by setting the conductive voltage value.

[Brief explanation of the drawing]

The drawings show one embodiment of the communication safety element unit according to the present invention, with Fig. 1 being a front view showing a unit of a button-shaped gas-filled discharge tube and a semiconductor safety element (thermistor), and Fig. 2 showing an adhesive layer. FIG. 3 is a front view showing a unit of semiconductor safety elements. A...Button-type gas-filled discharge tube, S...Thermistor,
V...Ballista, 2, 3, 4, 6, 7, 13, 1
4... Electrode, 11... Adhesive layer, 12... Conductive hole.

Claims (1)

[Scope of utility model registration request] The feature is that the electrode of the semiconductor safety element is bonded to the button-shaped gas-filled discharge tube or the electrode of the semiconductor safety element using an adhesive, and a conductive hole is provided which is locally broken by applying a constant voltage to the adhesive layer. Communication security element unit.