JPS59189604A - Method of producing nonlinear 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 relates to a method for manufacturing a non-linear resistor by improving the process of polishing a sintered body of zinc oxide and metal oxide. Concerning a method of manufacturing a body.

[Technical background of the invention and its problems] In the electrical system C2, an overvoltage control device is used to protect the electrical system by removing the overvoltage superimposed on the normal voltage.

This overvoltage protection device uses a non-linear resistor that exhibits almost insulating properties at normal voltage, but becomes relatively resistant when overvoltage is applied.

A non-linear resistor can be made by baking a molded material of silicon carbide (SiC) or zinc oxide (ZnO) mixed 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 SiC-based non-linear resistors. It can make an excellent overvoltage protection device.

However, ZnO-based non-linear resistors require many manufacturing processes, are difficult to mass-produce industrially, and suffer from a decline in non-linear resistance characteristics and large variations in their characteristics, as well as problems such as electrification life, discharge capacity, etc. There is a problem that other performance deterioration also occurs.

``Object 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] In order to achieve the above object, the present invention provides a manufacturing method C2 for a non-linear resistor in which an electrode is provided on a sintered body mainly composed of zinc oxide, and the present invention provides an electrode of a Maechichichi sintered body. 1-1
The feature is that after polishing to a surface roughness of 00 μm, an electrode is provided on this surface.

[Examples of the present invention] The present invention will be described below based on Examples. Bismuth oxide "" 20B is added to the main ingredient zinc oxide (ZnO) powder.
), antimony oxide (Sb208), chromium oxide (C
r20B) + Cobal oxide) (Coo) and powders such as manganese oxide (MnO) at a concentration of 0.01 to 6.0, respectively.
It is added within the range of mulch and mixed using, for example, a ball mill.

At this time, the oxide and an organic binder such as polyvinyl alcohol are mixed together. The mixture thus obtained is dried in a granulating device, for example a spray dryer.
Form into interspheroidal grains. This powdery mixture is pressed (yukake,
For example, it is formed into a disk with a diameter of 100 m and a thickness of 25 mm.

This molded product is fired and sintered in an electric furnace. The firing temperature is approximately 1300° C., and the appropriate time is, for example, 6 hours.

The disc-shaped sintered body after firing shrinks more than before sintering, but has a substantially homogeneous composition and density. Next, both halves of the disc-shaped sintered body are polished to different roughnesses, and metal spraying, for example, of aluminum is applied to the two halves to form electrodes and complete the non-linear resistor.

Figures 1 and 2 show the degree of variation in the nonlinear resistors manufactured in this way.
mA (Voltage between terminals when 1 mA flows through a non-linear resistor) Indicates the fluctuation rate. 10 to 40 samples were made for each half with different roughness, and svlmA was measured, and vl
The variation in mA was calculated. When the surface roughness is 1 to 100 μm, the voltage fluctuation is about 5 μm, but even if it is finer than 1 μm or rougher than 100 μm, the variation in vlmA becomes large, making it unsuitable as a nonlinear resistor. Ta.

Figure 2 shows a non-linear resistor designed with vlmA of 4000 V, and the horizontal axis shows vlm
A + Vertical axis g2 The generated quantity is shown as a relative value when the manufacturing quantity is set as 100%. Curve A shows the degree of effect achieved by the manufacturing method of the present invention, that is, the nonlinear resistor S2 in which the surface roughness of both halves is set to 1 to 100 μm. Curve B shows an example of a nonlinear resistor whose surface roughness is outside the above range.

As is clear from Fig. 2, it was confirmed that the nonlinear resistor produced by the manufacturing method of the present invention gathers around the designed vlmA of 4000 V, and the variation in electrical characteristics is small. Polishing both halves of the C sintered body to a surface roughness of 1 to 100 μm (Secondly, it is possible to strengthen the adhesion between the sintered body element and the sprayed aluminum that forms the electrode, and This contributes to preventing peeling of the metallicon (secondarily, a more stable non-linear resistor can be obtained).

[Effects of the Invention] As described above, according to the present invention, by polishing the surface of a sintered body mainly composed of zinc oxide to a surface roughness of 1 to 100 μm (second polishing and then attaching an electrode), variations in characteristics and performance can be reduced. A non-linear resistor with improved reduction can be provided.

[Brief explanation of the drawing]

FIGS. 1 and 2 are curve diagrams illustrating the electrical characteristics of a nonlinear resistor manufactured using the manufacturing process of the present invention.

Claims (1)

[Claims] In a method for manufacturing a non-linear resistor in which electrodes are provided on a sintered body mainly composed of zinc oxide, the surface of the sintered body on which the electrodes are provided is polished to a surface roughness of 1 to 100 μm, and then the surface is polished. A method of manufacturing a non-linear resistor, the method comprising providing an electrode.