JPS61229303A - Manufacture of non-linear resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a non-linear resistor, and more particularly to a method for manufacturing a non-linear resistor with an improved electrode attachment process.

[Technical background of the invention and its problems]

In electrical systems, overvoltage protection devices are used to protect the electrical system by removing overvoltages that are superimposed on normal voltages.

This overvoltage protection device uses a nonlinear resistor that exhibits substantially insulating properties at normal voltage and has a relatively high resistance value C when overvoltage is applied.

Non-linear resistors can be made by baking a molded material made by mixing zinc oxide (ZnO) with a metal oxide.

ZnO-based non-linear resistors have steep non-linear characteristics in the small current range and have a sharp rise up to large current ranges, so they are more effective than overvoltage protection devices using 8iC-based non-linear resistors. It can make an excellent overvoltage protection device.

However, ZsO-based nonlinear resistors require many manufacturing processes and are difficult to mass-produce industrially, resulting in a decrease in nonlinear resistance characteristics and large variations in characteristics, and problems such as energized life, discharge capacity, etc. There is a problem that other performance deterioration also occurs.

For example, generally, a high-resistance layer is applied to the side surface of a disc-shaped sintered body, baked, and then one probe surface is polished and an electrode is applied to this surface.This electrode formation process is as follows: As shown in FIG.
Using this jig, the gage surface side of the sintered body 3 is covered, and metallization is performed using aluminum, for example, to form the electrode 2 and complete the non-linear resistor. However, this jig 1
When using a or lb, the adhesion to the side surface of the sintered body is not good, so the electrode material adheres to the circumferential part of the probe surface and the side surface, and the metal contact size is 0.1 to 1 .6
The standard for providing m margins could not be met. This is jig 1
This is due to the mismatch between the distance between the opposing surfaces of the flanges Ial and lbl of the jigs la and lb and the thickness of the sintered body 3 when the contact surfaces of a and lb are still in contact with each other.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for manufacturing a non-linear resistor in which variation in characteristics and deterioration in performance are improved.

[Summary of the invention]

To achieve this object, the present invention provides a method for manufacturing a non-linear resistor in which electrodes are provided on a sintered body mainly composed of zinc oxide, in which the electrodes of the sintered body are provided with an asymmetric structure. The electrode is applied using a jig made of elastic resin.

[Example of the present invention]

Hereinafter, the present invention will be explained based on examples. Bismuth oxide (ntto) is added to zinc oxide (ZnO) powder, which is the main component.
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*Oxidized C7A (Crabs) #Copal oxide) (
Powders of manganese oxide (MnO) and manganese oxide (MnO) are added in a range of 0.01 to 6.0 mol each, and mixed in a ball mill. At this time, the oxide and an organic binder such as polyvinyl alcohol are mixed simultaneously. The mixture thus obtained is placed in a dry granulation device, for example a spray dryer, to form spherical agglomerates. This powdery mixture was pressed and formed into a disc with a diameter of IQQw and a thickness of 25111II.

This molded product is fired and sintered in an electric furnace. The firing temperature is approximately 13,000 ℃, and the appropriate time is 6 hours.

The disc-shaped sintered body after firing shrinks more than before sintering, but has a substantially homogeneous composition and density. A high-resistance layer is applied to the side surface of this fired product and baked, and the probe surface is polished. Then the first
As shown in the figure, the sintered body 5 was covered with jigs 4m and 4b made of elastic resin having an asymmetrical structure to prevent electrode material from adhering to the surface circumference and side surfaces. It is something.

That is, the side parts of A4a and A4b are 4ml and 4bl.
Structure with and without slopes in opposite directions at the tips.

When the two jigs 4m and 4b are butted against each other, the inclined surfaces of the jigs 4m and 4b match and abut each other. f&, A4a is inclined in such a direction that the inner surface is long and the outer surface is short, and the jig 4b is inclined in such a direction that the inner surface is short and the outer surface is long, contrary to the jig 4a. Therefore, when the two jigs 4a and 4b of the sintered body 5C are placed over each other, the inner surfaces of the seven flange 42°4b2 of the jigs 4m and 4b are in good contact with the plane of the sintered body 5 because of the inclined surfaces. With the sintered body 5 in close contact with the planar circumferential portion and side surface using a jig, the electrode 6 is formed on the planar surface using aluminum metallicon.

The degree of variation in the nonlinear resistors manufactured in this manner is shown in FIGS. 2 and 3.

Figure 2 shows a non-linear resistor designed with V and A at 4000V, and shows the variation in voltage. v1+aA I on the horizontal axis
The vertical axis shows the relative value of the quantity generated when the production quantity is set to 100%. The curved figure shows the degree of effect achieved by the manufacturing method of the present invention, that is, a cure made of elastic resin having an asymmetrical structure. Curve B shows an example of a non-linear resistor in which the electrode material is formed using a conventional symmetrical half-shaped jig.

As is clear from FIG. 2, it was confirmed that the designed V1wam of the nonlinear resistor produced by the manufacturing method of the present invention was concentrated around 4000 W, and the variation in electrical characteristics was small.

FIG. 3 shows variations in the margins of metallization on the surface of a nonlinear resistor. The horizontal axis shows the size of the metallic contact margin, and the vertical axis shows the relative value of the amount generated when the manufacturing quantity is set to 100%. A curved figure shows an example of a non-linear resistor according to the present invention,
Curve B shows an example of a nonlinear resistor manufactured using a conventional symmetrical half-split jig.

As is clear from FIG. 3, the nonlinear resistor according to the present invention is
The variation in the dimensions of the metallcon margin was small and the standards could be met.

As mentioned above, when performing metallization, the sintered body is covered with a pair of jigs made of elastic resin that have an asymmetrical structure with sloped parts in opposite directions on the abutting surfaces. , the margins of the metallicon can be made uniform, and the discharge withstand characteristics are better than those manufactured using the conventional symmetrical Ushiwariho jig because there is no electrode material adhering to the sides, so side flashing etc. Destruction is eliminated and a higher quality non-linear resistor can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a pair of elastic resin materials having an asymmetrical structure with inclined portions in opposite directions on the abutting surfaces of a sintered body containing zinc oxide as a main component are provided. By using a specific electrode material, it is possible to provide a nonlinear resistor with improved characteristics variation and performance deterioration.

[Brief explanation of drawings]

The first factor is a side view showing an embodiment of the nonlinear resistor of the present invention.
FIGS. 2 and 3 are curve diagrams illustrating the electrical characteristics and quality characteristics of the nonlinear resistor of the present invention, and FIG. 4 is a side view showing an example of a conventional nonlinear resistor. 4m, 4b = Jig 4ml, 4bl''・Side part 4m2.4b2...7 Lunge 6...Sintered body 6...Electrode agent Kensuke Chika (and 1 other person) J, 9
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Claims (1)

[Claims] In a non-linear resistor made by mixing an oxide with zinc oxide and firing it, when polishing both planes of the sintered body and providing electrodes, there is a mutually abutting surface that covers the plane circumference and side surfaces of the sintered body. A method for manufacturing a non-linear resistor, characterized in that electrodes are attached using a jig made of elastic resin and having an asymmetrical structure with inclined surfaces.