KR790000886B1 - Oxide megativity resistor - Google Patents

Abstract

An oxide negative resistor having s-type characteristics of negative resistance was comprised of a sintered body including 20 to 39.9 mol% of ZnO, 10 to 60 mol% of MgO and 0.1 to 20 mol% of MnO2. A prebaked mixture of ZnO, MgO and MnO2 was crushed by a ball mill, so that the compounded powder was obtained. After polyvinyl alcohol(binder) was added to the powder, and molded by a press at 0.8 ton/cm3, the molded powder was sintered in an electric furnace maintained at a temp. of 1100 to 1300≰C for 2hr, and the negative resistor was obtained.

Description

Oxide negative resistor

1 is a curve diagram showing current-voltage characteristics of the negative resistor of the present invention.

2 is a plan view showing a configuration example of the negative resistance of the present invention

The present invention relates to an oxide negative resistor.

Conventionally, N-characteristics typified by dynatron and S-shaped negative-resistance characteristic typified by a discharge tube are known as negative-to-negative resistor elements. In addition, in semiconductor negative resistors, there are a point contact transistor, an Esaki diode (both N-type negative resistance characteristics), a pnpn diode controlled rectifier, an electron decay diode (all S-shaped negative resistance characteristics), and the like. However, this type of semiconductor negative resistor is not only inferior in stability to temperature change, but also needs to be bonded to any semiconductor in the semiconductor. Therefore, it is difficult to manufacture, and the manufacturing process is complicated and the price is complicated. On the other hand, there were also expensive defects. On the other hand, in the case of oxide sintered bodies such as Fe ₂ O ₂ and Fe ₃ O ₄ containing NiO and CuO, negative resistance characteristics were observed, but the manufacturing method was complicated, and stability, reproducibility, etc. There is a problem and it is not put to practical use.

As the negative resistance element or negative resistor, a ZnO series sintered body containing 0.05 to 15.0 mol% of MgF ₂ , MnF ₂ , CdF ₂ and the like is also known. However, since ZnO-based negative resistors containing fluorides contain relatively unstable fluorides, they cannot be said to be sufficient in practical use because of their difficulty in reproducibility in manufacturing or problems in stability in use.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an oxide negative resistor having an S-shaped negative resistance characteristic which is easy to manufacture, has reproducibility, good characteristics and excellent stability. Incidentally, the characteristics of the S-shaped negative resistance to negative resistance element are generally the same as those in FIG. In this case, the negative resistance is evaluated by the negative resistance parameter n expressed by the following equation.

However, VP and IP represent voltage and current at point P, respectively, and VQ and IQ represent voltage and current at point Q, respectively.

Since n is a parameter representing the sharp degree of the OPQ curve in FIG. 1, the larger the value is, the better the value is.

Hereinafter, the present invention will be described in detail the negative resistance of the present invention as an essential component,

ZnO is 89.9-20 mol%

MgO is 10.0-60 mol% and

0.1 to 20 mol% MnO

It is characterized in that the sintered body is selected as the main body of the negative resistance.

Such an oxide negative resistance main body of the present invention can be produced, for example, by the following method. That is, the raw material oxides weighed in the correct proportion with respect to the predetermined composition ratio are mixed by a bowl mill, prebaked at a relatively low temperature, for example, 600 to 900 ° C, and then pulverized as a bowl mill to prepare a powder. In addition, as a raw material used at this time, the compound which turns into an oxide by heating, for example, hydroxide, a carbonate, a oxalate, can also be used. A binder such as polyvinyl alcohol was added to the prepared powder thus obtained and pressure-molded at a pressure of about 100 kg / cm ^{2 to 1} ton / cm ² , and a diameter of 20 m / m and a thickness of about 1 m / m. Finish with disc type.

The firing is sufficient to be performed at about 1,000 to 1,300 ° C, and the atmosphere gas at the time of the firing is generally an air atmosphere, and the holding at the highest temperature is generally about 1 to 5 hours.

Next, the reason for limiting the composition range of the oxide negative resistance main body as described above is as follows.

First, when the amount of MnO ₂ is less than 0.1 mol%, the above-described negative resistance parameter n becomes 5 or less, and no negative resistor suitable for application in a wide range of fields is obtained. By the same theory, even when MnO ₂ is more than 20 mol%, ZnO is less than 20 mol%, and again MgO is outside the range of 10 to 60 mol (and therefore ZnO is more than 89.9%), n is 5 or less. No desired negative resistor can be obtained. By the way, the negative-resistive body according to the present invention may be composed of only these three elements by selecting ZnO MgO and MnO ₂ within the composition range described above, but may add other metal oxide components.

Hereinafter, embodiments of the present invention will be described.

90-18 mol% of ZnO

10.0-62 mol% MgO

0 to 22 mol% MnO ₂

As a total of 100 mol%, ZnO, MgO, and MnO ₂ were each accurately and basis weight in a predetermined composition ratio, and these compounds were mixed by bowl mill. Subsequently, these mixtures were prebaked at 800 ° C. for 1 hour, ground again by a bowl mill, and 30 kinds of prepared powders including the reference example were obtained as raw materials. Thereafter, polyvinyl alcohol (caking agent) was added to these preparation powders and press-molded at a pressure of 0.8 ton / cm ² , and then the furnace was placed in an electric furnace at which the furnace temperature was set at 1,100 to 1,300 ° C. The negative electrode body of the circular plate of 20Φ * 0.5cm <^3> was obtained by holding and sintering.

The resistive body to which the silver electrode was attached by the general method was comprised with respect to the disk-shaped resistive body obtained by the above, respectively. The silver (Ag) of the electrode is Ag or Ag ₂ O as a starting material, and the result is the same, that is, it is only required to be in the state of baking after firing, and the baking temperature of the electrode is excellent in the stability of the resistor body. For example, it can be baked at a wide range of temperatures of 400 to 800 ° C.

2 is a configuration diagram of the negative resistor of the present invention, where 1 is a negative resistor main body, (2) and (2 ') are electrodes, and (3) and (3') are lead wires.

TABLE 1

For each sample obtained as described above, voltage-current characteristics at room temperature were measured by a standard circuit, and Vp, Ip, V _Q and n were obtained, respectively, and the results were obtained together with the composition ratio of the sintered body (negative resistor body). It is shown in Table 1.

The load life test (1000 hours at 70 ° C.) and the temperature characteristic test (-20 to 60 ° C.) and the characteristic test (1 year of room temperature) over time were carried out for some kinds of the above examples. It is shown in-4th table.

Load life characteristic

TABLE 2

Temperature characteristic

TABLE 3

Characteristics over time

TABLE 4

When the load life test is explained, the change rate Δn of the negative resistance parameter is 3% or more when the negative resistance of the ZnO series containing the conventional fluoride is left at 70 ° C. for 1,000 hours. It was excellent at less than 3%. The temperature characteristic of Vp is -0.05% / degrees C or less, as is clear from Table 3, compared with the temperature coefficient of 0.1% / degrees C of the conventional semiconductor negative resistor, which is very excellent. Also, as is clear from Table 4, the change over time of n is also very stable, which is ± 2% or less.

As described above, the oxide negative resistance of the present invention is not only superior in characteristics to the conventional one, but also inexpensive in terms of price, easy to manufacture, and industrially advantageous.

Claims (1)

As an essential ingredient ZnO is 89.9-20 mol% MgO is 10.0-60 mol% and MnO ₂ 0.1-20 mol% An oxide negative resistor, characterized in that the sintered body containing the resin is formed as a resistor body.

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