JPS60169105A - Voltage 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 Field of the Invention The present invention relates to a voltage nonlinear resistor whose main component is zinc oxide.

BACKGROUND ART In general, this type of voltage nonlinear resistor has excellent nonlinearity and is therefore suitably used in surge absorbers of electrical equipment and the like. The production of this kind of voltage nonlinear resistor is
Bismuth oxide (B) is added to zinc oxide (ZnO) as the main component.
It is carried out by mixing several additive components including 110al as subcomponents, molding the mixture, and then firing it. The reason why bismuth oxide is added here is that since it has a lower melting point than zinc oxide, it promotes crystal growth of zinc oxide particles through liquid phase sintering, but conventionally, bismuth oxide was added to promote crystal growth of zinc oxide particles by liquid phase sintering. For example, bismuth oxide was used in a large amount of 0.3 mol%.

By the way, when manufacturing a voltage non-linear resistor, in order to improve the life characteristics of the resistor or to insulate the outer periphery of the resistor, it is necessary to heat the resistor at a temperature of 400 to 700°C after sintering.
This post-sintering heat treatment changes the crystal system of bismuth oxide. For this reason, the electrical characteristics of the voltage nonlinear resistor are greatly reduced, and the degree of this is greater as the heat treatment temperature is higher. As a result, conventional resistors can obtain good characteristics with α (non-linear index) of 20 or more in a certain current range (for example, 100 μA to IAI), but outside that range, the non-linear index In addition to these problems, the metal component B1 of Bi and O8, which are the main components of the additive, has a Clark number of 2 X to-1' and is a scarce resource. There is also.

Purpose of the Invention The present invention was made against this background.
The purpose of this invention is to provide a voltage nonlinear resistor that can suppress the content of Bi and O among the additive components to a trace amount and improve various electronic characteristics such as nonlinear characteristics. be.

Summary of the Invention The first invention is characterized by containing zinc oxide (ZnO1 as the main component, manganese oxide (Mn0.1), antimony oxide (5b20sl%), chromium oxide (Cr*Osl,
Bismuth oxide (BilOll % aluminum oxide, mu)
A first component containing AJlo, l as an additive component, lead oxide (pbo), antimony oxide (Sb, O,), chromium oxide (0r1031° zinc oxide (ZnO), cobalt oxide (Co, O,), and manganese oxide). (MnOH
) and a second component obtained by mixing and calcining the mixture to form a sintered body.

The characteristics of the second @ Ming are that ZnO is the main component,
Mn01, s'b, o,, Or20g, A' 20Rb
The first component containing Bi203 as an additive component, the second component described above, and zinc borosilicate glass are mixed and sintered.

EXAMPLES Hereinafter, examples of the present invention will be described, and characteristics of resistors of the examples will be explained with reference to the drawings.

The voltage nonlinear resistor according to the embodiment of the first invention is made of Zn09
g, 467 mol e4, Bitog 0.03% /
l/%, Mn020.5-v-le4.5JO3o,
5-11-ruti, Or, 030.5-E-A.

Section, AI, os 3/1000 The first component obtained by weighing and mixing a predetermined amount to make a morch, pbo,
The second component obtained by calcining a mixed powder containing 0rlO1゜sb, o, in a molar ratio of 4:]:x was added to the second component.
It is obtained by mixing and sintering the components so that the content ratio with respect to the whole is 2 parts by weight.

To describe a specific example of constructing such a resistor, first, a predetermined amount of each powder of PbO%0r203, sb, and O is weighed in the above proportions, and the weighed materials are thoroughly mixed in a centrifugal ball mill, and then alumina powder is mixed. Temperature 1000℃ in the pot
The resultant calcined powder is pulverized in a centrifugal ball mill to obtain a reaction product, which is the second component. -10,000 ZnO1
Bi, O,, he, O,, MnO,, sb, o,, 0r
20. A predetermined amount of each powder is weighed in the above ratio, 2 weights of the above reaction product are added thereto, and then thoroughly mixed in a rotary ball mill and formed into a disk shape.

Next, the molded body was fired in air at a temperature of 1130°C for 6 hours, and both end faces of the obtained sintered body were polished and A was applied to both end faces.
A electrode is applied to g' and heat treated at a temperature of 590''C for 1 hour, thereby obtaining a voltage nonlinear resistor.

By calcining the mixture of pbo, 5b2o, and cr20H, a reactant containing pyrochlore crystals as a main component can be obtained. In order to investigate this, the above calcined powder was subjected to X-ray diffraction, and the X-ray diffraction pattern was as shown in FIG. This shows that the main component of the reactant is pyrochlore crystals.

Next, we will discuss the device characteristics of the voltage nonlinear resistor (this will be referred to as resistor A) manufactured as described above and the conventional resistor whose additives include Ei and O. Figure 2 is a graph showing the voltage-current characteristics with current on the horizontal axis and voltage on the vertical axis, and Figure 3 shows the heat treatment temperature, v1mV/ and α before and after heat treatment.
The graph shows the relationship between the change rate of V1mA/fl and the change rate of This is a graph showing the rate of increase in leakage current when a DC voltage of 2 is applied, with the horizontal axis representing the voltage application time and the vertical axis representing the rate of increase in leakage current. In FIGS. 2 to 4, 1 and 2 indicate the characteristics of resistor A and a conventional resistor, respectively, and 2' indicates AA! , O□ content ratio was set to 20/1000 mol ratio. Also, v1A/all is the voltage across the resistor when a current of 1mA is passed through a resistor with a thickness of 11, and α is the voltage at both ends of the resistor.
Assuming that a voltage of K V (vl) is generated when a current is passed through Al, it is an index expressed by k = < 4. K is a non-linear resistance.Also, this α varies depending on the current value, Generally, a value when a current in the range of 0.1 mA to 1 mA is applied is often used, and the value in this range will be adopted below.

First, looking at FIG. 2, the slope of curve 1 is smaller than the slope of curve 2 in the micro current region and the large current region. Here, α increases as the slope of the curve in Figure 2 decreases, so in the micro current region and large current region, the α of resistor A is larger than that of the conventional resistor, and its nonlinear characteristics are excellent. It is understood that there are Especially h
Since it contains lJ, ○, α in the large current region is large.

Also, looking at Figure 3, in the conventional resistor, v
The heat treatment temperature for both 1mA/IIIj and α is 500
When the temperature rises above around ℃, it rapidly decreases as the temperature increases, and a decrease in characteristics is seen.However, in the resistor A of the example, both vlmA/all and α hardly change due to heat treatment. It can be seen that the characteristics do not deteriorate. The curve indicated by 1' in FIG. 3 will be described later. Furthermore, looking at Figure 4, the increase rate of leakage current in the resistor A of the example is smaller than that of the conventional resistor, and the increase rate of the leakage current is smaller than that of the conventional resistor. It is understood that the properties are good.

Figure 5 shows the content ratio of ha, o, (
) for the first component, v25KA/V
It is a graph examining how 1 mA (the ratio of the voltage of the resistor when a current of 2.5 Kh is applied to the voltage of the resistor when a current of 1 mA is applied) and α change. Solid line A, change in v2.5KA/vlmA, B.

indicates the change in α. However, AA! , O, and other additive components are fixed as in the examples.

As mentioned earlier, h12o plays the role of increasing α in the large current region, but in order to obtain this effect, 0.2/1ooo
It is necessary to include more than the mole value. As shown in Figure 5, if it contains 0.2/1000 mole or more, V25
The value of KA/v1e is small and has good characteristics.

However, if the content ratio of hl, o, exceeds 20/1000 molar ratio, α becomes small, so in the end, Al, o,
It is necessary to contain 0.2/1000 to 20/1000 mole. Also Mn Oisb, oc
A similar measurement was conducted for r2os, and it was found that in order to obtain good characteristics, it is necessary to contain each in a content ratio of 0.1 to 5 moles (relative to the first component). Ta. A similar measurement was conducted for the reaction product, and it was found that in order to obtain good properties, it is necessary to contain it at a content ratio of 0.2 to 2 degrees by weight (relative to the whole). It turns out.

Regarding the blending ratio of the above reaction products, pbo, sb,
It may be any compound that forms pyrochlore crystals containing o, and is not limited to the blending ratio shown in the examples. Regarding its composition, pbo%S 1) 201bO
r, O, (7) combination Seno et al., PbO and sb, o,
A similar effect can be expected if this is combined with at least one of 0r20H1ZnO1 (3o, o3, and MnO2).

The calcination temperature and time in the calcination step to obtain the above reaction product are 80°C to 1.100°C and 1.1°C, respectively.
It is desirable that the time is in the range of ~10 hours. The reason for this is that if the calcination temperature is higher than 800°C or the calcination time is shorter than 1 hour, the reaction will not be carried out sufficiently.
This is because if the temperature is higher than 100° C. or the calcination time is longer than 10 hours, the degree of volatilization of pbo will increase and the nonlinear characteristics will deteriorate.

The firing temperature and firing time in the firing step after mixing the first component and the second component are preferably 950 to 1350 "C and 1 to 20 hours, respectively. The reason is that the firing temperature is
If the temperature is lower than 50°C or the firing time is shorter than 1 hour, a dense and uniform sintered body cannot be obtained; if the firing temperature is higher than 1350"C or the firing time is shorter than 20 hours. This is because if the length is too long, the degree of volatilization of pbo, Bi, O, and the like near the surface will increase, resulting in poor nonlinear characteristics.

Here, talking about the roles of Bi and Q, Figure 6 shows the relationship between the firing temperature in the firing process after mixing the first component and the second component, and α and v1A/IIs.
The solid line 3.4 shows the results of investigation with and without addition of i, O, and 0.03 mol 4, respectively.
■1mA/&1 for those with added Bi, O,
It shows a change in 1 and a change in α. In this case, the other additive components of the resistor are the same as those of resistor A. As is clear from the figure, the maximum firing temperature range can be expanded by adding trace amounts of Bi and O.

In order to obtain the effect of widening the optimum firing temperature, it is necessary that the content ratio of Bi and O be 0.014 or more. The reason for this effect is Bi,
This is thought to be due to the addition of a combination of O. and the reaction product. On the other hand, as the content ratio of Bi and O increases, the rate of decrease in α after heat treatment increases, and the degree of decrease increases as the heat treatment temperature increases. The solid line 1' in Figure 3 is α for the case where 0.1 molar percentage of Bi, O, is added.
This solid line 1' and the solid line 1 (Bi
, 0.0.034 addition), Bi, O,
The one with 0.1 molar addition of Bi, O,
The rate of decrease in α is greater than that with 3 molar addition. From the comparison between solid line 1' and solid line 2 (conventional resistor), B
A resistor with 0.1 mole of i and O can have better characteristics than conventional resistors, but when the content ratio of Bi and O exceeds 0.1 mole, the characteristics of the conventional resistor become worse. As it gets closer, it becomes ineffective. Therefore, the content ratio of Bi and O needs to be in the range of 0.01 to 0.1 molar ratio.

Further, the heat treatment temperature of the sintered body is preferably 500 to 850°C; if it is lower than 500°C, the life characteristics will be poor, and if it is higher than 850°C, the nonlinear characteristics will be poor.

In the above embodiments, a centrifugal ball mill and an aluminium crucible were used to manufacture the resistor.

The type of equipment may be any suitable for the purpose and is not limited to these types.

Next, the second invention will be described. The voltage nonlinear resistor according to the embodiment of the second invention contains 98,467 mol of ZnO, M
n0.0.5 %le, sl), Ono, 5 mol, O
rl o, 0.5 mole, "vos 3/100
0 mole q6, a first component consisting of B1t030.03 mo/L/ti, pbo, cr20. , sb, o, in a molar ratio of 4: ]: 1. A second component obtained by calcining a mixed powder and a zinc borosilicate glass, the content of the second component being 2% by weight. , the content of zinc borosilicate glass is 0
．． It was obtained by mixing and sintering 2% by weight and the remainder being the first component.

To describe a specific example of manufacturing such a resistor, first, a reaction product as the second component was obtained in the same manner as in the embodiment of the first invention, and on the other hand, ZnO%Bi, 03 , MrxOl,
Weigh out a predetermined amount of each powder of sb, o, 0r20B, hll, o, in the above ratio, add 2 parts by weight and 0.2 parts by weight of the above reaction product and zinc borosilicate glass, respectively, Thereafter, a voltage nonlinear resistor is obtained in the same manner as in the embodiment of the invention described in Part 1.

Next, we compared the device characteristics of the voltage nonlinear resistor (this will be referred to as resistor B) manufactured as described above and a conventional resistor whose main additives are Bi and O. To describe the results, Fig. 7 is a graph showing voltage-current characteristics with current on the horizontal axis and voltage on the vertical axis, and Fig. 8 is a graph showing voltage-current characteristics with current on the horizontal axis and voltage on the vertical axis, and Fig. 8 shows V1mA/! This is a graph showing the rate of increase in leakage current when a DC voltage of 85 hours is applied to ET1, with the horizontal axis representing the charging time and the vertical axis representing the rate of increase in leakage current. In FIGS. 7 and 8, 7 and 2 indicate the characteristics of resistor B and the conventional resistor, respectively, and 8
The following shows the characteristics of a resistor manufactured in the same manner as in the example except that the content ratio of hl and o was set to 20/1000 molar ratio.

As can be seen from FIG. 7, the resistor B according to the embodiment has a larger α than the conventional resistor in the micro current region and the large current region, and has an Ae similar to the invention.

0 is included, so α is particularly large in the large current region. Furthermore, as can be seen from FIG. 8, resistor B has a smaller leakage current increase rate and better life characteristics than the conventional resistor.

Figure 9 shows the content ratio of zinc borosilicate glass (relative to the whole)
This is a graph that examines how α changes when . Indicates the changed characteristics. From this result, in order to obtain good properties, for zinc borosilicate glass, it is necessary to
5 weight 1AA! For the same reason as mentioned above, it is necessary to contain 0.2/1000 to 20/1000 mol of 20s.

Here, for resistor B which is an embodiment of the second invention, when we investigated the relationship between the rate of change of V1]IIA/u and α before and after heat treatment (heat treatment performed for the purpose of improving life characteristics, etc.), we found that the first As in the case of resistor A, which is an example of the invention, no change in characteristics was observed.

Also, in the second invention, Bi, 03 plays the role of obtaining a wide optimum firing temperature, just as in the case of the first invention, and its content ratio is 0.01 to 0 for the same reason. .It is necessary to have a value of 1 mole.

Regarding the reaction product which is the second component, the compounding ratio, combination of components, calcination conditions, etc. are completely the same as in the case of the first invention, and furthermore, the calcination after mixing the first component and the second component The conditions and the heat treatment conditions after sintering are also exactly the same as in the case of the first invention.

Effects of the Invention As described above, according to the present invention, a large amount of Bi, 03 is used as the main component of the additive (PbO%Bb,O.

reaction products whose main component is pyrochlore crystals,
Since it contains Mn01, sb, o, , or, o, hl, o, etc. as additive components, good characteristics can be obtained while suppressing Bi and O to trace amounts. Moreover, its characteristics are better than those of conventional resistors whose main additives are Bi and Oa. That is, conventional Bi, O.

Compared to voltage non-linear resistors that add a large amount of , the electrical properties decrease less due to heat treatment after sintering, and the electrical properties can be almost completely changed by heat treatment in the normal temperature range (400°C to 900°C) in the heat treatment process. Does not decrease. As a result, the nonlinear index in the microcurrent region and the large current region is larger than that of the conventional device, and since the nonlinear index in the microcurrent region is large, the leakage current during power application is small.

Moreover, the increase in leakage current due to long-term dielectricity is small, and long-life surge absorption electrons can be obtained. And by adding the reaction product as the second component in combination with Bi, O,! & It becomes possible to widen the range of suitable firing temperatures, making it easier to control the manufacturing process. Also, Bi, Os(B
This is advantageous in terms of resources compared to using a large number of 2×10-towns in i. The reason for this is that among the metal components used as additive components, those with a small Clark number are Co
(Clarke number 4X1δ) pb (Clarke number 1.5
10-”), Sb (Clarke number 5×10), but among these, C05pb is much more abundant than B1, and sb is less abundant than B1, but B1 in the conventional case This is because the content ratio is not large as in P'b.In addition to the above-mentioned effects, P'b can be
There is almost no volatilization of O, Bi, and O, which is advantageous in terms of occupational hygiene and environment.

[Brief explanation of the drawing]

Figure 1 is an X-ray diffraction diagram of an example of the reaction product used in the present invention, Figure 2 is a voltage-current characteristic diagram of a voltage nonlinear resistor, and Figure 3 is a diagram of voltage-current characteristics of a voltage nonlinear resistor.
The figure shows v1/I vs. heat treatment temperature of voltage nonlinear resistor.
Figure 4 is a graph showing the change in Ij and α, Figure 4 is a graph showing the rate of increase in leakage current with respect to the energization time of the voltage non-linear resistor, and Figure 5 is the graph showing the change in the rate of increase in leakage current with respect to the voltage non-linear resistor's additive component content. Figure 6 is a graph showing the linear characteristics of a voltage non-linear resistor, and Figures 7 to 9 are voltage-current characteristic diagrams of the voltage non-linear resistor, and 2 is a graph showing the rate of increase in leakage current with respect to electric time, and a graph showing nonlinear characteristics with respect to the content ratio of additive components.

Claims (1)

[Claims] (1) Manganese oxide 0.1 to 5 mol, antimony oxide 0.1 to 5 mol, chromium oxide 0.1 to 5 mol, aluminum oxide 0.2/1000 to 20/1000 mol%
A mixture of one or more of chromium oxide, zinc oxide, cobalt oxide, and manganese oxide, and lead oxide and antimony oxide is added to the first component consisting of 0.01 to 0.1 mole of bismuth oxide and the balance zinc oxide. A voltage nonlinear resistor that is specially designed to be formed by mixing and sintering a second component obtained by calcining so that the content of the second component is 0.2 to 20% by weight based on the total content of the second component. . C) Manganese oxide 0.1-5 mol%, antimony oxide 0.1-5 mol%, chromium oxide 0.1-5 mol%, aluminum oxide 0.2/1000-20/1000
A first component consisting of 0.01 to 0.1 mol of bismuth oxide with the balance being zinc oxide, one or more of chromium oxide, zinc oxide, cobalt oxide and manganese oxide, and lead oxide and antimony oxide. The second component obtained by calcining the mixture and the zinc borosilicate glass are mixed and sintered, and the content of the second component is 0.2 to 20% by weight, and the content of the zinc borosilicate glass is 0.2 to 20% by weight. 0.01 to 5% by weight, the remainder being primary
Voltage nonlinear resistor characterized by being a component.