JPH05243011A - Voltage nonlinear resistor and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the defective junction of a baked body and an electrode when the electrode is mounted to a voltage nonlinear resistor, and to omit a complicate process such as masking on the surface of the baked body. CONSTITUTION:Zinc oxide is used as a main component, one or more kinds of metallic oxides for displaying voltage nonlinearity are added and mixed to zinc oxide, the mixture is formed, and the molded form is baked, thus acquiring a discoidal baked body 3. Plate-shaped electrodes 4 are thermocompression- joined with the electrode forming surfaces such as end faces 3a of the baked body 3. The plate-shaped electrodes 14 are employed as the electrodes of a voltage nonlinear resistor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage non-linear resistor containing zinc oxide as a main component and containing an additive for exhibiting voltage non-linearity, and a method for producing the same.

Voltage non-linear resistors containing zinc oxide as a main component have excellent non-linear voltage-current characteristics, and are therefore widely used in lightning arresters and surge absorbers for the purpose of voltage stabilization or surge absorption. .. To manufacture such a voltage non-linear resistor, bismuth oxide, antimony oxide, cobalt oxide, zinc oxide,
Add silicon oxide etc. and mix, dry this mixed powder,
This was granulated and molded, and the molded body was fired to obtain a fired body. Then, the electrode was formed by spraying aluminum metallikon onto the electrode formation surface of the fired body.

[0003]

However, when the electrode film was formed by thermal spraying, there was a problem of poor adhesion at the interface with the fired body. That is, at the interface between the two, there was a non-contact portion of the electrode film that could not be discerned from the appearance, and in some cases, the electrode film was peeled off. Further, when spraying the fired body, it was necessary to accurately mask a portion not provided with an electrode in accordance with the dimensions of the fired body and remove the mask after the spraying. Performing such work for each product requires extremely troublesome work.

An object of the present invention is to eliminate a defective joint between a fired body and an electrode and to eliminate the complicated step of masking the surface of the fired body.

[0005]

The present invention is directed to a fired body containing zinc oxide as a main component and containing a metal oxide for exhibiting voltage non-linearity, and thermocompression bonding to the electrode forming surface of the fired body. The present invention relates to a voltage non-linear resistor, characterized in that the voltage non-linear resistor is provided.

In the present invention, zinc oxide is a main component, and one or more metal oxides for exhibiting voltage non-linearity are added to and mixed with each other, the mixture is molded, and the molded body is fired. Then, in the method for producing a voltage non-linear resistor by providing at least an electrode on the fired body, a plate-shaped electrode is thermocompression bonded to the electrode forming surface of the fired body,
The present invention relates to a method of manufacturing a voltage nonlinear resistor.

[0007]

The present inventor discovered for the first time that the plate electrode can be thermocompression bonded by pressing the plate electrode against the electrode forming surface of the fired body containing zinc oxide as a main component, and applying heat and pressure.
The present invention has been completed. In addition, it has been found that, in important characteristics such as voltage non-linearity, it is possible to obtain characteristics which are completely the same as those of the current general-purpose product, which is a resistor provided with an aluminum metallikon electrode. In addition, in the present invention, defective bonding between the electrode and the fired body did not occur, and the product yield was improved.

[0008]

EXAMPLE One or more kinds of metal oxides for exhibiting voltage non-linearity are added to and mixed with zinc oxide powder.
Examples of such metal oxides include bismuth oxide, cobalt oxide, antimony oxide, chromium oxide, manganese oxide, nickel oxide, alumina and silica. Then, this mixture is wet-mixed with, for example, a ball mill,
It is dried and granulated, and this granulated powder is molded into a predetermined shape. The molded body is preferably degreased to obtain a degreased body, and then the degreased body is fired according to a predetermined firing schedule to obtain a fired body.

In this embodiment, a disc-shaped fired body 3 as shown in FIG. 1 is produced. On the other hand, one set of flat plate electrodes 4 is prepared, and each flat plate electrode 4 is pressed against the end surface 3 a of the fired body 3. Then, a pressure is applied to the plate-like electrode 4 by the pair of push rods 2 and the electric furnace 1 is heated. The heating temperature at this time is preferably 300 to 600 ° C. Further, the material of the flat plate-shaped electrode 4 is preferably aluminum. However, as long as it is a commonly used electrode material and can be deformed by heat and pressure, it can be used without any problem. Also, the heating temperature can be changed according to the material.

The present inventor has also discovered that the plate electrodes can be simultaneously thermocompression bonded to a plurality of fired bodies. This aspect will be described with reference to FIG. First, the fired body 3 and the plate-shaped electrode 4 are alternately stacked in the vertical direction to produce a laminated body. The flat plate-shaped electrodes 4 are arranged on the upper end and the lower end of the laminated body. In this state, the laminated body is heated while being pressed in the vertical direction, and the fired body 3 and the flat plate-shaped electrode 4 which are adjacent to each other are thermocompression bonded.

According to such a method, the flat plate-shaped electrodes 4 can be simultaneously hot-press bonded to the plurality of fired bodies 3 in one step. Then, in this state, it can be used for a lightning arrester or the like.
Therefore, the number of steps can be further reduced and the manufacturing cost can be reduced as compared with the conventional method in which the electrodes are individually attached to the fired body 3. Further, conventionally, both end surfaces 3a of each fired body 3
An aluminum metallikon electrode film was provided on the substrate, then a plurality of fired bodies were stacked in multiple stages, and the surfaces of the electrode films were brought into contact with each other. However, the contact between the electrode films is not always good, and the voltage nonlinearity or the like may be deteriorated when stacked in multiple stages. In this respect, in the present example, since the adjacent fired bodies 3 are joined to the single plate-shaped electrode 4, the above-mentioned problem of poor contact between the electrode films cannot occur, and they are stacked in multiple stages. It was also found that the characteristic of the voltage non-linear resistor is exhibited without causing the characteristic deterioration.

(Experiment 1) Further specific experimental results will be described. ZnO, Bi ₂ O ₃ , Sb ₂ O ₃ , Co ₂ O ₃ , MnO ₂ , SiO ₂ , Al ₂ O
_{Using 3} as a raw material, a disc-shaped fired body 3 having a thickness of 5 mm and a diameter of 30 mm was obtained by the above method. Further, a flat plate electrode 4 made of aluminum having a thickness of 0.3 mm and a diameter of 20 mm was prepared. Using a push rod 2 made of silicon nitride, thermocompression bonding was performed at a temperature of 350 ° C. and a pressure of 200 kg. In this way, 100 voltage non-linear resistors of the present invention were produced, but no electrode bonding failure was observed. On the other hand, an end face 3a of the disk-shaped fired body 3 was sprayed with aluminum metallikon to form an electrode film (control example).
For each of these voltage non-linear resistors, the limiting voltage ratio V
_{40 KA} / V _{1 mA} was measured, and the results are shown in Table 1. From this result, it can be seen that the voltage non-linear characteristic which is completely equivalent to the conventional one can be obtained also in the present invention example.

[0013]

[Table 1]

(Experiment 2) The laminated bodies of the voltage nonlinear resistors were laminated by laminating the number of the fired bodies 3 of Experiment 1 shown in Table 2 and performing thermocompression bonding according to the method described with reference to FIG. It was manufactured (invention example). Moreover, the number of resistors having the aluminum metallikon electrode film produced in Experiment 1 was laminated as shown in Table 2 (control example). And for each example, V _40KA
/ V _1mA was measured and the results are shown in Table 2.

[0015]

[Table 2]

In the control example, V increases as the number of stacks increases.
_40KA / V _1mA increased. It is considered that this is due to poor contact between the electrode films. In contrast,
In the example of the present invention, the original characteristics of the resistor were not impaired even if the number of stacks increased.

[0017]

As described above, according to the present invention, the plate electrode can be thermocompression bonded by pressing the plate electrode against the electrode forming surface of the fired body containing zinc oxide as a main component and applying heat and pressure. .. Moreover, in terms of important characteristics such as voltage non-linearity, it is possible to obtain characteristics which are completely equivalent to those of the resistors provided with the aluminum metallikon electrodes, which are currently general-purpose products. In addition, in the present invention, defective bonding between the electrode and the fired body did not occur, and the product yield was improved. Further, unlike the conventional case, the step of masking the surface of the fired body becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a schematic view showing a straight state in which a flat electrode 4 is thermocompression bonded to a fired body 3.

FIG. 2 is a front view showing a state in which a plate electrode 4 and a fired body 3 are stacked.

[Explanation of symbols]

 3 Disc-shaped fired body 4 Flat plate electrode

Claims (4)

[Claims] 1. A fired body containing zinc oxide as a main component and containing a metal oxide for exhibiting voltage non-linearity, and a plate-like electrode thermocompression-bonded to an electrode forming surface of the fired body. A voltage non-linear resistor characterized in that 2. A plurality of the fired bodies are arranged so that the electrode forming surfaces face each other, and the plate-shaped electrodes are thermocompression bonded to the opposing electrode forming surfaces, and the adjacent fired bodies are The integrated structure according to claim 1, wherein the plate-shaped electrodes are integrated.
The voltage nonlinear resistor described. 3. Zinc oxide as a main component, one or more kinds of metal oxides for exhibiting voltage non-linearity are added thereto and mixed, the mixture is molded, and the molded body is fired.
A method for producing a voltage non-linear resistor by providing at least an electrode on the fired body, wherein a plate-shaped electrode is thermocompression bonded to the electrode forming surface of the fired body, the method for producing the voltage non-linear resistor. .. 4. A plurality of the fired bodies are arranged so that the electrode forming surfaces face each other, the plate-shaped electrode is sandwiched between the electrode forming surfaces facing each other, and the plate forming electrodes face each other. 4. The method for producing a voltage non-linear resistor according to claim 3, wherein the plate-shaped electrodes are subjected to thermocompression bonding at the same time, and the adjacent fired bodies are integrated by the plate-shaped electrodes.