JPS60170208A - 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 Technical Field The present invention relates to a voltage nonlinear resistor containing zinc oxide as a main component.

Conventional technology Zinc oxide (ZnOl) is a main component of a voltage non-voltage resistor (hereinafter referred to as RZNN tatami 21 J-), which is used in semiconductor devices such as thyristors and surge absorbers for electrical equipment, etc. This type of ZnO element is
, ZnOIICIt bismuth as the main component (
It is obtained by mixing several types of additives including Bi, O, and L as subcomponents, and molding and sintering the mixture.

Here, since Ei and O have a lower melting point than ZnOIC, they are added to promote crystal growth of ZnO particles by liquid phase sintering. However, in the past, in order to fully demonstrate its function, Bi2O,
It was used in large quantities at 0.3 mol or more based on all components.

In the manufacture of ZnO elements, a heat treatment process using sintering acid at 400 to 900° C. is required in order to improve the life characteristics of the ZnO elements and to provide an insulating coating on the outer periphery of the ZnO insulator. However, due to such heat treatment, the crystal structure of % Bi, O, changed, and the electrical characteristics of the ZnO element were significantly deteriorated. The degree of the decrease is greater as the heat treatment temperature range is higher. Such a conventional ZnO element has a certain current range (for example, 100 μA).
~IA), α (nonlinear index) is 20 or more, which is satisfactory, but outside the above range, α is extremely low.

In addition, as mentioned above, Bi and Os are used extensively as additives, but the Clark number of the bismuth (B1) element system is 2 x 1.0"-', and B1□0. It is extremely poor.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a long-life voltage nonlinear resistor that can be manufactured without using 1ABi and 03, which are scarce in resources, and has excellent electrical characteristics. The purpose is to provide

SUMMARY OF THE INVENTION In order to achieve the above object, the invention No. 1 provides a method for manufacturing manganese oxide (MnOs) 0.1 to 5 mol, antimony oxide; Cobalt oxide (C
! o, O, l O, 1-5 mol%, oxidized T # Mi =
Ram (Ad, O,) o, 271000~20/1
000 molar ratio, and for the first component consisting of the remainder ZnO, e
Any one or more of r203, ZnO, Cocoj and Mno, lead oxide (pbo) and s
b, o.

A second component formed by calcining a mixture consisting of 02 to 2
A ZnO element is obtained by adding zero weight and sintering it.

The second invention is MnO,0,1-5Mo"'1*s
b, o.

01-5 mol%, cr, o, 0.1-5 mo Jl
/4, co, o.

A first component consisting of 0.1 to 5 molar ratio and the balance being ZnO, zinc borosilicate glass, and the second component, each component having a composition of zinc borosilicate glass 0801 to 5 weight i1% and the second component 0. 2
~20 layers were mixed so that the remainder was the first component, and the mixture was sintered to form a ZnO element.

The third invention is MnO, o, 1 to 5 mo, II/q
lp, sb, o.

Q, 1-5 Mok%, Cr, Q, Q. 1-5
Mol%, Co, 0°0.1-5 mole ratio, hl, o
, 0.2/1000 to 20/1000 moles, balance Z
The first component consisting of nO, the zinc borosilicate glass, and the second component are each composed of 1 part of borosilicate and 0.0 part of the zinc oxide glass.
A ZnO element is obtained by mixing 1 to 5 layers, a second component of 0.2 to 20 layers, and the remainder being the first component, and sintering them.

EXAMPLES Below, each of the first to third embodiments of the present invention will be described in detail.

I) An embodiment of the first invention First, a predetermined amount of each powder of PbO, 0r20B, sb, and o was weighed in a molar ratio of 4:]:1, and each of the weighed powders was milled in a centrifugal ball mill. The mixture was thoroughly mixed to obtain a mixed powder. Thereafter, this mixed powder was calcined in an aluminum crucible at a firing temperature of 11,000° C. for 4 hours, and this calcined body was pulverized in a centrifugal ball mill to obtain a reaction product as the second component.

On the other hand, the first component contained 97,997 moles of ZnO.

Mn010.5 mol4, sb, o3o, 5 mol4, 0r2030.57k'Z, 0Oz03
0.5 Mok%, A#, o, 3/1000%
#cl.

A predetermined amount was weighed. Then, 2 weights of the above reaction product were added to the first component, and then thoroughly mixed in a rotary ball mill and formed into a disk shape.

Next, this molded body was fired in the air at a firing temperature of 1100C for 6 hours, and then both end faces of the obtained sintered body were polished, silver (Agl electrodes) were applied to both end faces, and the body was heated at a temperature of 590°C for 6 hours.
A heat treatment was performed for several hours to obtain a voltage nonlinear resistor (ZnO element).

Here, regarding the reaction product obtained by calcining a mixed powder of PbO, Cr, O,, Sb, O, X, I11! When diffraction was performed, the X-ray diffraction pattern was as shown in FIG. As a result of assigning /gnal in FIG. 1, it was found that the reaction product was formed mainly of pyrochlore crystals py.

FIG. 2 is a graph showing the r-pressure-*fN characteristics of the ZnO element of this example, with the horizontal axis representing current and the vertical axis representing voltage. In FIG. 2, the solid line ] represents the Zn of this example.
The characteristics of the O element are shown, and the actual M2 is Biρ.

The graph shows the characteristics of a conventional ZnO element containing additives as main components, and the slope of the solid line 2 is smaller than the slope of the solid line 2 in the microcurrent region and the large current region. Here, since α is larger as the slope of the solid line in FIG. 2 is smaller, it can be seen that the ZnO element of this example has better non-@ line characteristics than the conventional ZnO element. In particular, ha
2o, α in the large current region becomes large.

Furthermore, FIG. 3 shows the relationship between each heat treatment temperature and the coughing rate of Vl mA /vl and α before and after the heat treatment when the temperature of the heat treatment, which is the final step in the ZnO strand manufacturing process, is varied. In the graph shown, the horizontal axis shows the heat treatment temperature, and the vertical axis shows each rate of change.

Note that the heat treatment time was 1 hour at each temperature.

Here, VtmA/d is the voltage at both ends when a current of 1 mA is passed through a ZnO element with a thickness of 1.7", and α is the voltage at both ends of the ZnO element with a thickness of 1.7".
V (vl
If a voltage of The value when current is applied is often used, and below, values within this range will be adopted.

In FIG. 3, real NM3 and 4 indicate the α and v1111A/1M characteristics of the ZnO element of this example, respectively, and solid lines 5 and 6 indicate the conventional ZnO with Bi2O3 as the main component of the splint. α and v1mA of the chordae/
+a (1)%. When the odor of the conventional ZnO element rises above about 500"C, the characteristics rapidly decrease as the temperature rises. In contrast, in the ZnO element of this example, It can be seen that the characteristics of both α and V111nA/tomo hardly change due to heat treatment.

Furthermore, Fig. 4 is a graph showing the rate of increase in side current when a DC voltage of 85 mA/l is applied in a constant temperature bath at a temperature of 1ffi 130'C, with the horizontal axis representing the voltage application time and the vertical axis representing the voltage application time. is the leakage current increase rate.

In FIG. 4, the solid line 7 shows the characteristics of the ZnO element of this example, and the solid line 8 shows the characteristics of the ZnO element of this example. The solid line 9 shows the characteristics of the ZnO element of this example in which the content ratio of Ic Both the example and the ZnO element of the other example shown by the solid line 9,
Leakage current increase rate is lower than conventional products.

It can be seen that the life characteristics are good.

Furthermore, FIG. 5 shows co, o, or h120. This is a graph showing how α changes to vCK when the content ratio of each component is changed, and the horizontal axis shows the content ratio of each component.

α is plotted on the vertical axis. In Figure 5, solid line 1
0, the content ratios of Co and Os are changed, the content ratios of other cooling components are the same as in the examples, and the timeliness of α is determined when the content ratio of ZnO is increased or decreased in accordance with Co and Os. show. In addition, solid line 11 shows the results when the content ratios of p, lj, and o are changed, and the content ratios of other additive components are made similar to those in the example without adding Co and O, and when adjusted with ZnO. This shows the characteristics of α.

As can be seen from Figure 5, in order to have good characteristics, C
o20. is required to be contained in the first component in a range of 0.1 to 5 molar proportions. Maku, Al, O.

As mentioned above, it is necessary to contain 0.2/1000 molar or more in order to increase α- in the large current region, but as shown in FIG.
If it exceeds 0.2/1000 molar ratio, α becomes smaller, so it is necessary to contain it in the first component in the range of 0.2/1000 to 20/1000 molar ratio.

In addition, as mentioned above, in the same way that the effective content ratio of 00203 etc. was confirmed, other additive components, namely Mn
02.5b20. , Or, 03, an experiment on the reaction product revealed that in order to obtain good properties, Mn
O.

sb, o, and Or2 o3 are each contained in the first component in the range of 0.1-5 molar, and the reaction product is in the first component.
It was necessary that the content be in the range of 02 to 20% by weight based on the components.

II 1 An Example of the Second Invention First, a reaction product as the second component was obtained in the same manner as in the Example of the first invention.

10,000, as the first component, Zn098.0 mol 1゜Mn0
20.5 mol%, Sb, o, o, 5 mol%,
0rlOH0,5mol4, Co,01o,5
A predetermined amount of mol was weighed. Then this first component is 97
．． 8-fold fi1. The reaction products were weighed so as to have a double weight ratio and the borosilicate zinc glass to be a 0.2 weight ratio, and these were thoroughly mixed in a rotary ball mill and formed into a disk shape.

Next, in the same manner as in the first embodiment of the invention, this molded body was fired, Ag electrodes were applied to both end faces, and heat treatment was performed to obtain a ZnO element.

FIG. 6 is a graph showing the voltage-current characteristics of the ZnO element of this example, with the horizontal axis representing the current and the vertical axis representing the voltage. In FIG. 6, the solid line 12 represents the ZnO of this example.
The characteristics of the device are shown, and the solid line 2 represents Bi and O.

This shows the characteristics of a conventional ZnO element with additives as the main component, and in the microcurrent region and large current region, the slope of solid line 12 is smaller than the slope of solid line 2,
It can be seen that the ZnO element of this example has better nonlinear characteristics than the conventional product.

In addition, Fig. 7 shows that V1 in a thermostat at a temperature of 130°C
This is a graph showing the rate of increase in leakage current when a DC voltage of 85 mA/+Lg is applied, with the horizontal axis representing the voltage application time and the vertical axis representing the rate of increase in leakage current.

In FIG. 7, the solid line 13 shows the characteristics of the ZnO element of this example, and the solid line 8 shows the characteristics of the conventional product containing Bi, 03 as the main component of the additive. It can be seen that the rate of increase in leakage current is lower than that of conventional products, and the life characteristics are good.

Furthermore, Figure 8 is a graph showing how α changes when the content ratio of zinc borosilicate glass is changed, with the content ratio of zinc borosilicate glass on the horizontal axis and α on the vertical axis. This is what I took. In FIG. 8, a solid line 14 indicates that the content ratio of zinc borosilicate glass is changed, the content ratio of the reaction product is fixed at 2 i%, and each component in the first component is changed as in the example. [Part 1] The characteristics of α are shown when the content ratio of all the components is increased or decreased in accordance with the zinc borosilicate glass.

As can be seen from FIG. 8, in order to obtain good properties, it is necessary that the zinc borosilicate glass be contained in the range of 0.01 to 5 weight percent of the total weight.

In addition, as mentioned above, in the same way as confirming the effective content ratio of zinc borosilicate glass, other additive components, namely M
n01,8b203,0rlO1,0010,, After experimenting with the reaction products, in order to obtain good characteristics, MnO2, Sb! 01, Cr20B and C
It was necessary that O and O were each contained in the first component in a range of 0.1 to 5 mol%, and that the reaction product was contained in a range of 02 to 20% by weight of the total.

111) An example of the third invention First, a reaction product as the second component was obtained in the same manner as in the example of the first invention.

10,000, as the first component, ZnO97,997 mol%, M
n0,0.5 mol'1, Sb, O, 0,5 mol%
, (jr2030.5 moles, (!o, Os o,
5 mol p ATo Os 3/1000 mol coefficient was weighed. Thereafter, the first component was 97.8% by weight, the reaction product was 2% by weight, and the zinc borosilicate glass was 0% by weight.
．． They were each weighed so as to have a double weight of 1%, mixed thoroughly in a rotary ball mill, and formed into a disk shape.

Next, in the same manner as in the embodiment of the first invention, this molded body is fired, and Ag'l! is applied to both end surfaces. A ZnO element was obtained by applying an electrode and performing heat treatment.

FIG. 9 is a graph showing the voltage-current characteristics of the ZnO element of this example, with the horizontal axis representing the current and the vertical axis representing the voltage. In FIG. 9, the solid line 15 represents the ZnO of this example.
Showing the characteristics of the element, Meiren 2 is Bi! O.

This shows the characteristics of the conventional ZnO element with additives as the main component, and in the micro-flow region and large-flow region,
The slope of the solid line 15 is smaller than the slope of the solid line 2Ω, and it can be seen that the ZnO element of this example has better nonlinear characteristics than the conventional product. In particular, since Achi03 is contained, α in the large current region becomes large.

Fig. 10 is a graph showing the rate of increase in leakage current when a DC voltage of 85% vl mA/I'' is applied in a thermostatic chamber at a temperature of 130'C, with the horizontal axis representing the voltage application time and the vertical axis representing the rate of increase in leakage current. is the leakage current increase rate.

In FIG. 10, a solid line 16 shows the characteristics of the ZnO element of this example, a solid line 8 shows the characteristics of the conventional product whose main additive is Bi2O, and a solid line 17 shows the characteristics of the ZnO element of this example, especially J, This shows the characteristics of the Zn, O element when the content ratio of o is set to 20/1.000 molar ratio, and both the ZnO element of this example and the other example shown by the solid line 17 have a higher value than the conventional product. It can be seen that the leakage current boosting n rate is small and the life characteristics are good.

Furthermore, FIG. 11 shows 0o20. Or borosilicate zinc glass 4! This is a graph showing how α changes when the r-owned ratio is changed, and the horizontal axis shows the content ratio of each component,
α is plotted on the vertical axis. In FIG. 11, a solid line 18 indicates the case where the content ratio of Co, O, is changed, the content ratio of other additive components is the same as in the example, and the content ratio of ZnO is increased or decreased corresponding to Oo, 03. α of In addition, the solid line 19 shows that the content ratio of zinc borosilicate glass is changed, the content ratio of the reaction product is fixed at double i%, and each component in VC in the first component is different from Example 1a.
The aromaticity of α is shown when the content ratio of the entire first component is increased or decreased in accordance with the zinc borosilicate glass as shown in J. - As can be seen from Figure 11, in order to obtain good characteristics,
Co, O, is contained in the first component in the range of 0.1 to 5 mol, and the zinc borosilicate glass is contained in the range of 001 to 5 in the whole.
It is necessary that the content be within one weight range.

In addition, as mentioned above, in the same way that the effective content ratio of 0o20H etc. was confirmed, other additive components, namely MnO
,, S'b203 , 0r203 , A1201 ,
An experiment on the reaction product revealed that MnO2, 5b2
03 and Or2 o.

are contained in the first component in the range of 0.2/1000-20/1 in the range of 0.2/1000-20/1, respectively.
It was necessary that the reaction product was contained in the first component in a range of 0.000 molar parts, and that the reaction product was contained in a range of 0.2 to 20 molar parts in the whole.

By the way, Z in each embodiment of the second and third inventions
When we investigated the changes in VlmA /m and α before and after the heat treatment when the temperature of the heat treatment, which is the final step in the ZnO element manufacturing process, was varied, we found that the ZnO element in the example of the first invention alike,
The properties hardly changed due to heat treatment.

Note that the first and third aspects of the present invention are not limited to the valley embodiment. That is, in each of the above examples, the blending ratio of one reaction product is pbo: sb convex & F: O
r20g" 4:1:1, fc is not limited to the working example. In other words, any blending ratio may be used as long as pyrochlore crystals are generated after calcination.Also, regarding the ingredients. PbO, Sb, 03°O
Not limited to the combination of r, O, (3r20.,
1a1 or more of ZnO, 0o201 and MnO2 and pb.

Irocroa crystals are generated and have a similar effect. Further, the calcination temperature and the calcination time in the calcination step for obtaining the reaction product are preferably in the range of 800 to 100"C and 1 to 10 hours, respectively. In some cases, the reaction is slow, ]100"C
If it exceeds 100%, a large amount of PbO will volatilize,
Furthermore, if the calcination time is less than 1 hour, the reaction will be insufficient, and if it exceeds 10 hours, the degree of volatilization of pbo will increase.

- It is preferable that the firing temperature and firing time in the firing step after mixing the first component and the second component (reaction product) etc. are in the range of 1000 to 1300' IC and 1 to 20 hours, respectively. . If the firing temperature is less than 1000°C, a dense sintered body will not be obtained, if it exceeds 1300°C, pbo will volatilize and the nonlinear characteristics will deteriorate, and if the firing time is less than 1 hour, it will not be possible to obtain a dense sintered body. This is because a uniform sintered body cannot be obtained, and if the time exceeds 20 hours, pbo near the surface will volatilize, resulting in poor nonlinear characteristics.

Moreover, it is preferable that the heat treatment temperature of the sintered body is in the range of 500 to 850°C. This is because if the heat treatment temperature is less than 500°C, the life characteristics of the obtained ZnO element will be poor, and if it exceeds 850°C, the nonlinear characteristics will be poor.

In addition, in each of the above examples, in manufacturing the ZnO element,
Although a centrifugal ball mill, an alumina crucible, etc. were used, the types of these instruments may be any suitable for the purpose, and are not limited to the instruments used in each of the above embodiments.

Effects of the Invention As described above, according to the first to third aspects of the present invention, since Bi and O, which have conventionally been used in large amounts as additives, are not used at all, the nonlinear characteristics do not deteriorate due to heat treatment. The non-linear index in the micro current region and the large current region is larger than that of the conventional one, and since the non-linear index in the micro current region is % larger, the leakage current during power application is small. Furthermore, since the increase in leakage current due to long-term energization is small, a surge absorbing element with a long life can be obtained. Furthermore, the Clark number is 2×1
Since PbO or the like having a Clark number of 1.5 x to-' is used instead of Bi, O, which is 0-1 and poor in terms of resources, it is advantageous in terms of resources.

[Brief explanation of the drawing]

Figure 1 shows the reactant X used in an embodiment of the first invention.
A line diffraction diagram, FIG. 2 shows ZnO according to an embodiment of the first invention.
Voltage-TiL current characteristic diagram of the device; Figure 3 is a graph showing changes in 1 mA/rraa and α with respect to heat treatment temperature of the ZnO element; Figure 4 is a graph showing α when the ZnO element is energized; Fig. 6 is a pressure-current characteristic diagram of a ZnO element according to an embodiment of the second invention, Fig. 7 is a graph showing the leakage current increase rate with respect to energization time of the ZnO element, and Fig. 8 is a graph showing the rate of increase in leakage current with respect to the energization time of the ZnO element. 9 is a graph showing α when the content ratio of zinc borosilicate glass is changed in FIG.
Fig. 1O is a graph showing the increase rate of leakage JIL flow with respect to the energization time of the ZnO element, and Fig. 11 is a graph showing the increase rate of leakage JlL flow with respect to the energization time of the ZnO element.
3 is a graph showing α when the content ratio of ZnO, 03 or borosilicate zinc glass is changed. 2nd r21 Benururitsui L - (”C) 51st f

Claims (1)

[Claims] (0.1 to 5 moles of 11 manganese oxide, 0.1 to 5 moles of antimony oxide, 0.1 to 5 moles of chromium oxide, 0.1 to 5 moles of cobalt oxide, 0 moles of aluminum oxide) .2/1
000 to 20/1000 molti, the balance consisting of zinc oxide, a mixture consisting of any one or more of chromium 6' zinc oxide, 11m cobalt and manganese oxide, lead oxide and antimony oxide. A voltage nonlinear resistor characterized in that it is made by adding 0.2 to 20% of a calcined second component and sintering it. (2+ Manganese oxide 0.1-5 moles? Antimony oxide 0.1-5 moles, chromium oxide 0.1-5 moles, cobalt oxide 0.1-5 moles, balance zinc oxide. and a second component formed by calcining a mixture consisting of zinc borosilicate glass, and any one or more of chromium oxide, zinc oxide, cobalt oxide, and manganese oxide, and lead oxide and antimony oxide, Voltage non-linearity characterized by mixing and sintering each component so that the composition of each component is 0.01-5% by weight of borosilicate zinc glass, 0.2-20% by weight of the second component, and the remainder being the first component. Resistor. Silk manganese oxide 0.1 to 5 mol, antimony oxide 0.
1 to 5 moles Chromium dodecide 0.1 to 5 moles, cobalt oxide 0.1 to 5 moles, aluminum oxide 0.2/100
0 to 20/1000 molar ratio, a first component consisting of zinc oxide, the balance being zinc borosilicate glass, one or more of chromium oxide, zinc oxide, cobalt oxide and manganese oxide, and lead oxide and antimony oxide. and a second component formed by calcining a mixture consisting of
1. A voltage nonlinear resistor, characterized in that the voltage nonlinear resistor is obtained by mixing and sintering the mixture so that the weight ratio is 0 and the remainder is a first component.