JP2934387B2 - Manufacturing method of semiconductor porcelain - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing semiconductor porcelain for porcelain capacitors, porcelain varistors and the like.

[0002]

2. Description of the Related Art Semiconductor ceramics containing SrTiO ₃ as a main component are widely used as elements such as capacitors, varistors and thermistors. As one of the methods of manufacturing these semiconductor porcelains, a main component made of SrTiO _{3 is} made of Nb, T
a, a valence controlling agent (semiconductor agent) such as a compound of a rare earth element, a grain boundary insulating agent composed of an oxide of Cu, Bi, Pb, and Mn, and a SiO ₂ , Al ₂ O ₃ , MnO _2, etc. A mixture to which a sintering aid is added is prepared to form a molded body, which is baked in a reducing atmosphere at 1350 to 1450 ° C. for about 2 hours. At 950 to 1200 ° C. for about 2 hours.

[0003]

By the way, Cu, Bi, as a valence controlling agent or a grain boundary insulating agent or a sintering aid are used.
Oxides such as Pb and Mn evaporate during firing in a reducing atmosphere or during heat treatment in an oxidizing atmosphere. The amount of evaporation changes depending on the temperature and / or time during firing or heat treatment. As a result, characteristic variations such as the apparent dielectric constant of the semiconductor porcelain occur.

Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor porcelain capable of suppressing the evaporation of additives and reducing the variation in characteristics.

[0005]

In order to achieve the above object, the present invention provides ABO ₃ (where A is Sr, Ba, Ca,
Any one or more elements of Mg, B is Ti,
O represents one or more elements of Zr, and O represents oxygen. A) forming a molded body containing a main component or a raw material capable of obtaining the main component, a valence controlling agent and a grain boundary insulating agent; and firing the molded body in a reducing atmosphere. Heat treating in an oxidizing atmosphere, the method comprising the steps of: producing a semiconductor porcelain wherein at least one of the grain boundary insulating agents is zirconate, titanate or silicate. is there. In addition, as shown in claim 2, a valence controlling agent (for example, B
i, Mn) can be zirconate or titanate or silicate. Further, as described in claim 3, the sintering aid (for example, Mn) can be zirconate, titanate or silicate. The raw material from which the main component can be obtained in the present invention is, for example, SrTiO ₃
SrCO ₃ and TiO ₂ , (SrCa) Ti to obtain
SrCO ₃ , CaCO ₃ and TiO ₂ to obtain O ₃ ,
BaCO ₃ and TiO ₂ for obtaining BaTiO ₃ . The valence controlling agent (semiconductor agent) is one or a plurality of compounds of Nb (niobium), Ta (tantalum), W (tungsten), and rare earth elements (Y, La, Ce, etc.). Examples of the metal that functions as the grain boundary insulating agent include Cu (copper), Pb (lead), Bi (bismuth), and Mn.
(Manganese), Tl (thallium), Sb (antimony), and Fe (iron). The zirconate is, for example, CuZrO ₃ , PbZrO ₃ , Bi ₄ Zr ₃ O ₁₂ , M
nZnO ₃ . Titanate is, for example, CuTi
O ₃ , PbTiO ₃ , Bi ₄ Ti ₃ O ₁₃ , MnTiO ₃
It is. Silicates include, for example, CuSiO ₃ , PbS
iO ₃ , Bi ₄ Si ₃ O ₁₂ and MnSiO ₃ . The preferred ratio of each component of the semiconductor porcelain is as follows. Main component 100 mol part Semiconducting agent 0.1-5.0 mol part Grain boundary insulating agent 0.05-5.0 mol part Firing in a reducing atmosphere is preferably 1300-1500 ° C.
For 1-5 hours. The heat treatment in an oxidizing atmosphere is preferably performed at 700 to 1200 ° C. for 1 to 5 hours.

[0006]

According to the invention of each claim, a grain boundary insulating agent or a valence controlling agent or a sintering aid which is easy to evaporate is added with a metal zirconate, titanate or silicate. Then, the evaporation is reduced as compared with the case where the conventional metal oxide is added. That is, zirconate, titanate, or silicate contains zircon, titanium, or silicon, which can be stably present at the grain boundary and can be dissolved in the main component, and is combined with these. Metals are also stably present at grain boundaries, and their evaporation is reduced. Further, since the metal is difficult to separate from zircon (Zr), titanium (Ti), or silicon (Si), the evaporation is suppressed. Therefore, even if the firing conditions or the heat treatment conditions fluctuate, the change in the amount of the additive is reduced, and the variation in the characteristics is reduced. Further, since evaporation is suppressed, target characteristics can be obtained.

[0007]

First Embodiment Next, a method for manufacturing a semiconductor ceramic for a capacitor and a capacitor according to an embodiment of the present invention will be described.

In the general formula ABO ₃ , S is Sr (strontium) and B is Ti (titanium). SrTiO ₃ (main component)
And Y ₂ which is a rare earth element compound as a valence controlling agent
O ₃ (yttrium oxide) and CuZr, a zirconate of Cu (copper) that mainly functions as a grain boundary insulating agent
O ₃ and SiO ₂ as a sintering aid were mixed in a proportion of SrTiO ₃ 100 mol part Y ₂ O ₃ 0.6 mol part CuZrO ₃ 0.05 to 3.00 mol part SiO ₂ 0.2 mol part And prepare them using a ball mill.
The mixture was wet-mixed for hours and then dried to obtain a powder of the raw material mixture. In addition, four kinds of samples of NO. 1 to NO. 4 were prepared by changing CuZrO ₃ into four stages of 0.05 mol part, 0.50 mol part, 1.00 mol part, and 3.00 mol part.

Next, an aqueous solution of polyvinyl alcohol as an organic binder was added to the raw material mixture of each sample in an amount of 10% by weight, mixed and granulated, and the granulated product was formed under a pressure of 1 ton / cm ² to form a diameter. A disk-shaped molded body having a thickness of 10 mm and a thickness of 0.5 mm was obtained. Next, this compact is placed in a furnace and the volume ratio of N
₂ : 1350 to 1450 in an N ₂ + H ₂ mixed gas atmosphere (non-oxidizing atmosphere or reducing atmosphere) of H ₂ = 99: 1.
C. for 2 hours, and then heat-treated at 950 to 1200.degree. C. for 2 hours in the air (oxidizing atmosphere) to form an insulating layer on the crystal grain boundaries, thereby completing the semiconductor porcelain of each sample. After firing, the semiconductor ceramic had a diameter of about 8 mm and a thickness of about 0.4 mm. In addition, as schematically shown in FIG. 1, the semiconductor porcelain 1 can be represented by semiconductor crystal grains 2 and a grain boundary insulating layer 3.

Next, a silver paste (conductive paste) is applied to both main surfaces of the semiconductor porcelain 1 of each sample by a printing method, and is baked at 800 ° C. for 1 hour in the air to form a pair of electrodes 4.
5 was formed, and the capacitor was completed. In addition, 100 capacitors having the same configuration were manufactured for each sample in order to examine the variation in characteristics.

Next, the apparent dielectric constant (ε), dielectric loss (tan δ), insulation resistance (IR), and yield index (variation) of the apparent dielectric constant ε of the capacitor of each sample were measured.
The results shown in the following Table 1 were obtained. The apparent dielectric constant ε and dielectric loss tan δ are 25 ° C., frequency 1 kHz, voltage 1 V
It measured on condition of. The insulation resistance IR was measured after applying DC 50 V for 1 minute at 25 ° C. The yield index was determined according to the following equation.

Yield index = standard deviation of permittivity ε / average value of permittivity ε

[0013] Table 1 Sample NO. Ε tan δ (%) IR (MΩ) yield index ^{1 41 × 10 3 1.1 21 ×} 10 4 0.04 2 49 × 10 3 0.5 17 × 10 4 0. 05 3 52 × 10 ³ 0.7 16 × 10 ⁴ 0.04 4 48 × 10 ³ 1.1 15 × 10 ⁴ 0.05

For comparison, Cu in Samples Nos. 1-4 was
Instead of ZrO ₃ , the conventional additive CuO is added to 0.0
5 mol parts, 0.50 mol parts, 1.00 mol parts, 3.00 mol parts
Except that the molar part was changed, capacitors of sample Nos. 5, 6, 7, and 8 were made with the same composition and the same method as sample Nos. 1 to 4, and the characteristics were measured by the same method. 2 results were obtained.

Table 2 Sample No. ε tan δ (%) IR (MΩ) Yield index 542 × 10 ³ 1.2 20 × 10 ⁴ 0.07 645 × 10 ³ 0.7 17 × 10 ⁴ 0. 06 7 50 × 10 ³ 0.7 16 × 10 ⁴ 0.09 8 44 × 10 ³ 0.9 16 × 10 ⁴ 0.11

In Samples Nos. 1 to 8, C before firing was
When the ratio of the amount of u (copper) to the amount of Cu after the calcination and the heat treatment for oxidation was determined, it was 8 in the samples Nos. 1 to 4 according to the present invention.
On the other hand, it is 65 to 75% in the sample Nos. 5 to 8 of the comparative example, and the scattering or evaporation of Cu during the calcination and the oxidative heat treatment is smaller than that of the conventional sample. There were few.

As is evident from the comparison between Tables 1 and 2, the yield indices of Samples Nos. 1 to 4 according to the present invention are smaller than those of Samples Nos. 5 to 8 which are comparative examples. Such a small yield index means that there is little variation in ε. According to the present invention, the variation in ε is reduced because
C that is difficult to evaporate without adding Cu as this oxide
This is because CuZrO ₃ which is a zirconate salt of u was added. When the variation in ε is small, the yield of the capacitor, that is, the yield is improved, and the cost can be reduced. In Samples Nos. 1 to 4, Cu evaporation was suppressed, so that ε, tan δ, and IR were the same as or superior to Sample Nos. 5 to 8.

[0018]

Second Embodiment CuZr can also be obtained by using Pb (lead) zirconate PbZrO ₃ instead of CuZrO _3.
In order to confirm that the same operation and effect as O ₃ were obtained, 0.05 mol part, 0.50 mol part, 1.00 mol part, and 3.00 mol part of CuZrO ₃ in the first embodiment were added. The capacitors of Sample Nos. 9, 10, 11, and 12 were made with the same composition and the same method as in the first embodiment except that the capacitor was replaced with ₃ , and the characteristics were measured by the same method as in the first embodiment. The results shown in the following Table 3 were obtained.

Table 3 Sample NO. Ε tan δ (%) IR (MΩ) Yield index 943 × 10 ³ 1.1 21 × 10 ⁴ 0.06 10 41 × 10 ³ 0.7 20 × 10 ⁴ 0. 05 11 45 × 10 ³ 0.6 18 × 10 ⁴ 0.05 12 47 × 10 ³ 0.9 21 × 10 ⁴ 0.06

For comparison with Sample Nos. 9 to 12, 0.05 mol part of PbO was used instead of PbZrO ₃ ,
Sample No. 1 was prepared in the same manner as Sample Nos. 9 to 12, except that 0.50 mol part, 1.00 mol part, and 3.00 mol part were added.
Make capacitors of 3, 14, 15, and 16 and use sample No. 9
When the characteristics were measured in the same manner as in Tables 1 to 12, the following Table 4 was obtained.
Was obtained.

Table 4 Sample No. ε tan δ (%) IR (MΩ) Yield index 13 41 × 10 ³ 1.3 20 × 10 ⁴ 0.06 14 42 × 10 ³ 0.8 21 × 10 ⁴ 0. 08 15 42 × 10 ³ 0.7 19 × 10 ⁴ 0.10 16 42 × 10 ³ 1.0 19 × 10 ⁴ 0.11

As is clear from the comparison between Table 3 and Table 4,
According to the samples Nos. 9 to 12 according to the present invention, the evaporation of Pb was suppressed in the same manner as in the Cu of the first embodiment, and the yield index became lower than the conventional value, and the same operation as in the first embodiment. The effect is obtained.

[0023]

Third Embodiment Instead of CuZrO ₃ of the first embodiment, Bi ₄ Zr which is a zirconate salt of Bi (bismuth) is used.
_In order to confirm that the same operation and effect as those of CuZrO ₃ of the first embodiment can be obtained even when ₃ O ₁₂ is used, 0.05 mol part of CuZrO ₃ in the first embodiment, 0.50
Mol part, 1.00 mol part, 3.00 mol part of Bi ₄ Zr
Capacitors of sample Nos. 17, 18, 19 and 20 were made with the same composition and the same method as in the first embodiment except that ₃ O ₁₂ was replaced, and the characteristics were measured by the same method as in the first embodiment. As a result, the results shown in the following Table 5 were obtained.

[0024] Table 5 Sample NO. Ε tan δ (%) IR (MΩ) yield index ^{17 42 × 10 3 1.3 20 ×} 10 4 0.05 18 45 × 10 3 0.5 20 × 10 4 0. 04 19 41 × 10 ³ 0.4 20 × 10 ⁴ 0.06 20 42 × 10 ³ 0.9 21 × 10 ⁴ 0.06

For comparison with Samples Nos. 17 to 20, conventional Bi ₂ O ₃ was used instead of Bi ₄ Zr ₃ O ₁₂ .
05 mol parts, 0.50 mol parts, 1.00 mol parts, 3.0
Except that 0 mol part was added, capacitors of Sample Nos. 21, 22, 23 and 24 were made in the same manner as Samples Nos. 17 to 20, and the characteristics were measured by the same method as Samples Nos. 17 to 20. The results in Table 6 below were obtained.

Table 6 Sample No. ε tan δ (%) IR (MΩ) Yield index 2140 × 10 ³ 1.1 19 × 10 ⁴ 0.07 22 45 × 10 ³ 0.8 20 × 10 ⁴ 0. 07 23 43 × 10 ³ 0.8 17 × 10 ⁴ 0.08 24 41 × 10 ³ 0.9 17 × 10 ⁴ 0.12

As is clear from the comparison between Table 5 and Table 6,
According to the sample Nos. 17 to 20 according to the present invention, the evaporation of Bi is suppressed as in the case of Cu of the first embodiment, and the yield index becomes equal to or less than the conventional value, and the same operation as that of the first embodiment. The effect is obtained.

[0028]

Fourth Embodiment Instead of CuZrO ₃ of the first embodiment, MnZ which is a zirconate of Mn (manganese) which functions as a grain boundary insulating agent, a sintering aid and a valence controlling agent.
In order to confirm that the same operation and effect as CuZrO ₃ can be obtained by using rO ₃ , the C
0.05 mol part, 0.50 mol part, 1.0 mol of uZrO ₃
Sample N was prepared in the same manner and in the same manner as in the first embodiment except that 0 mol part and 3.00 mol part of MnZrO ₃ were used.
O. Making capacitors of 25, 26, 27 and 28
When the characteristics were measured by the same method as in Example 1, the results shown in the following Table 7 were obtained.

[0029] Table 7 Sample NO. Ε tan δ (%) IR (MΩ) yield index ^{25 47 × 10 3 0.8 20 ×} 10 4 0.05 26 52 × 10 3 0.5 19 × 10 4 0. 05 27 46 × 10 ³ 0.7 22 × 10 ⁴ 0.05 28 41 × 10 ³ 0.9 21 × 10 ⁴ 0.06

For comparison with Sample Nos. 25 to 28, MnO ₂ which is an oxide of Mn was used instead of MnZrO ₃ .
Is 0.05 mol part, 0.50 mol part, 1.00 mol part,
Capacitors of Sample Nos. 29, 30, 31, and 32 were made in the same manner as Samples Nos. 25 to 28 except that 3.00 mol was added, and the characteristics were measured in the same manner as Samples Nos. 25 to 28. However, the results in Table 8 below were obtained.

Table 8 Sample No. ε tan δ (%) IR (MΩ) Yield index 2948 × 10 ³ 0.9 19 × 10 ⁴ 0.05 30 50 × 10 ³ 0.8 19 × 10 ⁴ 0. 06 31 43 × 10 ³ 0.9 20 × 10 ⁴ 0.06 32 45 × 10 ³ 1.0 21 × 10 ⁴ 0.08

As is clear from the comparison between Table 7 and Table 8,
According to the sample Nos. 25 to 28 according to the present invention, the evaporation of Mn is suppressed as in the case of Cu of the first embodiment, and the yield index becomes equal to or less than the conventional value, and the same operation as that of the first embodiment. The effect is obtained.

[0033]

Fifth Embodiment The CuZrO ₃ of the first to fourth embodiments,
Instead of PbZrO ₃ , Bi ₄ Zr ₃ O ₁₂ , and MnZrO ₃ , even if a plurality of types selected from these are added,
In order to confirm that the same operation and effect as those of the fourth embodiment can be obtained, the mixture of CuZrO ₃ of the first embodiment with 0.5 mol part of CuZrO ₃ and 0.5 mol part of PbZrO ₃ ( Sample No. 33), a mixture of 0.5 mol part of CuZrO ₃ and 0.5 mol part of Bi ₄ Zr ₃ O ₁₂ (Sample No. 33)
34), a mixture of 0.5 mol part of CuZrO ₃ and 0.5 mol part of MnZrO ₃ (sample No. 35), 0.5 mol part of PbZrO ₃ and 0.5 mol part of Bi ₄ Zr ₃ O ₁₂ (Sample No. 36), 0.5 mol part of PbZrO
₃ and 0.5 mol parts of MnZrO ₃ (sample NO.
37), the same composition and the same composition as in the first example except that the mixture was replaced with a mixture of 0.5 mol part of Bi ₄ Zr ₃ O ₁₂ and 0.5 mol part of MnZrO ₃ (sample No. 38). A capacitor was made by the method, and characteristics were measured by the same method as in the first embodiment. The results shown in Table 9 below were obtained.

[0034] Table 9 Sample NO. Ε tan δ (%) IR (MΩ) yield index ^{33 51 × 10 3 0.8 19 ×} 10 4 0.04 34 52 × 10 3 0.5 17 × 10 4 0. 04 35 54 × 10 ³ 0.7 16 × 10 ⁴ 0.06 36 51 × 10 ³ 0.8 17 × 10 ⁴ 0.05 37 52 × 10 ³ 0.8 19 × 10 ⁴ 0.04 38 46 × 10 ³ 0.6 21 × 10 ⁴ 0.06

For comparison with Samples Nos. 33 to 38, Samples Nos. 33 to 38 were prepared by replacing the zirconates of Cu, Pb, Bi and Mn with these oxides.
Samples Nos. 39, 40, 41, in the same manner as 33-38
Sample No. 33 ~
The characteristics were measured in the same manner as in Example 38.
Was obtained.

Table 10 Sample No. ε tan δ (%) IR (MΩ) Yield index 3950 × 10 ³ 0.8 17 × 10 ⁴ 0.10 40 48 × 10 ³ 0.7 17 × 10 ⁴ 0. 12 41 50 × 10 ³ 0.7 16 × 10 ⁴ 0.08 42 48 × 10 ³ 0.7 16 × 10 ⁴ 0.12 43 50 × 10 ³ 0.7 17 × 10 ⁴ 0.094 44 48 × 10 ³ 0.8 17 × 10 ⁴ 0.10

As is apparent from the comparison between Tables 9 and 10, according to the samples Nos. 33 to 38 according to the present invention, Cu,
Even when a plurality of types of zirconates of Pb, Bi, and Mn are added, evaporation of Cu, Pb, Bi, and Mn is suppressed, and the yield index becomes equal to or less than a conventional value. The same operation and effect can be obtained.

[0038]

Sixth Embodiment In order to confirm that the same function and effect as CuZrO ₃ can be obtained by using CuTiO ₃ which is a Cu titanate instead of CuZrO ₃ of the first embodiment, CuZrO ₃ in Example 1 was changed to 0.0
5 mol parts, 0.50 mol parts, 1.00 mol parts, 3.00 mol parts
Samples Nos. 45, 46, and 4 were prepared in the same manner and in the same manner as in the first embodiment except that the molar part of CuTiO ₃ was used.
When the capacitors of Nos. 7 and 48 were manufactured and their characteristics were measured by the same method as in the first embodiment, the results shown in the following Table 11 were obtained.

Table 11 Sample No. ε tan δ (%) IR (MΩ) Yield index 45 40 × 10 ³ 1.1 20 × 10 ⁴ 0.04 46 52 × 10 ³ 0.7 17 × 10 ⁴ 0. 05 47 50 × 10 ³ 0.7 17 × 10 ⁴ 0.06 48 48 × 10 ³ 0.9 16 × 10 ⁴ 0.06

As is clear from the comparison between Table 11 and Table 2, according to Sample Nos. 45 to 48 according to the present invention, Sample N
O. Compared to the case of using CuO of 5 to 8, the evaporation of Cu is suppressed in the same manner as in the first embodiment, and the yield index becomes equal to or less than the conventional value, and the same operation and effect as in the first embodiment. Is obtained.

[0041]

Seventh Embodiment In order to confirm that the same function and effect as CuZrO ₃ can be obtained by using PbTiO ₃ which is a titanate of Pb (lead) instead of CuZrO ₃ of the first embodiment. In the first embodiment, 0.05 mol part, 0.50 mol part, 1.00 mol part of CuZrO ₃ in the first embodiment,
3.00 Other replaced with PbTiO ₃ molar portion sample NO in the first embodiment the same composition as and the same method. 49,5
When capacitors 0, 51, and 52 were made and their characteristics were measured in the same manner as in the first embodiment, the results shown in the following Table 12 were obtained.

Table 12 Sample No. ε tan δ (%) IR (MΩ) Yield index 49 41 × 10 ³ 1.2 22 × 10 ⁴ 0.065 50 45 × 10 ³ 0.7 20 × 10 ⁴ 0. 06 51 42 × 10 ³ 0.7 18 × 10 ⁴ 0.07 52 42 × 10 ³ 0.9 19 × 10 ⁴ 0.07

As is clear from the comparison between Table 12 and Table 4, according to Sample Nos. 49 to 52 according to the present invention, Sample N
O. Compared to the case of PbO of 13 to 16, the evaporation of Pb is suppressed as in the case of Cu of the first embodiment, and the yield index is lower than the conventional value, which is the same as that of the first and second embodiments. The operation and effect of the invention are obtained.

[0044]

Eighth Embodiment Instead of CuZrO ₃ of the first embodiment, Bi which functions as a grain boundary insulating agent and a valence controlling agent is used.
To confirm that the same effects as CuZrO ₃ be used Bi ₄ Zr ₃ O ₁₂ is a titanate of (bismuth) is obtained, CuZrO ₃ in the first embodiment
Is 0.05 mol part, 0.50 mol part, 1.00 mol part,
Sample No. 5 having the same composition and the same method as the first embodiment except that 3.00 mol part of Bi ₄ Zr ₃ O ₁₂ was used.
3, 54, 55, and 56 capacitors were manufactured, and the characteristics were measured by the same method as in the first embodiment. The results shown in Table 13 below were obtained.

Table 13 Sample No. ε tan δ (%) IR (MΩ) Yield index 5342 × 10 ³ 1.0 19 × 10 ⁴ 0.05 54 45 × 10 ³ 0.8 19 × 10 ⁴ 0. 06 55 45 × 10 ³ 0.7 20 × 10 ⁴ 0.07 56 41 × 10 ³ 0.9 21 × 10 ⁴ 0.07

As is clear from the comparison between Table 13 and Table 6, according to the samples Nos. 53 to 56 according to the present invention, the first embodiment showed that the evaporation of Bi was smaller than that of Bi ₂ O _{3 in} Table 6. Similarly to the Cu of the example, the yield index is reduced to a value less than the conventional value, and the same operation and effect as those of the first and third embodiments can be obtained.

[0047]

Instead of CuZrO ₃ of the ninth embodiment] first embodiment, CuZrO be used MnTiO ₃ is a titanate of Mn which acts as a grain boundary insulation agent and sintering aid ₃
In order to confirm that the same function and effect as described above were obtained, 0.05 mol part of CuZrO ₃ in the first embodiment was added.
0.50 mol part, 1.00 mol part, 3.00 mol part of M
Capacitors of sample Nos. 57, 58, 59 and 60 were made with the same composition and the same method as in the first embodiment except that nTiO ₃ was used, and the characteristics were measured by the same method as in the first embodiment. However, the results shown in the following Table 14 were obtained.

Table 14 Sample No. ε tan δ (%) IR (MΩ) Yield index 57 50 × 10 ³ 0.9 19 × 10 ⁴ 0.04 58 52 × 10 ³ 0.8 18 × 10 ⁴ 0. 05 59 45 × 10 ³ 0.8 20 × 10 ⁴ 0.05 60 48 × 10 ³ 1.0 21 × 10 ⁴ 0.06

As is clear from the comparison between Table 14 and Table 8, according to the samples Nos. 57 to 60 according to the present invention, the evaporation of Mn was suppressed as in the case of Cu of the first embodiment, and the yield index was increased. Is less than the conventional value, and the same operational effects as those of the first and fourth embodiments can be obtained.

[0050]

Tenth Embodiment CuTi of the Sixth to Ninth Embodiments
O ₃ , PbTiO ₃ , Bi ₄ Ti ₃ O ₁₂ , MnTiO ₃
In order to confirm that the same operation and effect as those of the sixth to ninth embodiments can be obtained even if a plurality of types selected from these are added instead of CuZrO ₃ of the first embodiment, .
5 mol parts of CuTiO ₃ and 0.5 mol parts of PbTiO ₃
(Sample No. 61), 0.5 mol part of CuTi
A mixture of O ₃ and 0.5 mol part of Bi ₄ Ti ₃ O ₁₂ (sample No. 62), a mixture of 0.5 mol part of CuTiO ₃ and 0.5 mol part of MnTiO ₃ (sample NO. 63) ), 0.
5 mol parts of PbTiO ₃ and 0.5 mol parts of Bi ₄ Ti ₃
Mixture with O ₁₂ (sample no. 64), 0.5 mol part Pb
A mixture of TiO ₃ and 0.5 mol part of MnTiO ₃ (Sample No. 65), 0.5 mol part of Bi ₄ Ti ₃ O ₁₂ and 0.1 mol part of MnTiO ₃ .
A capacitor was made with the same composition and method as in the first embodiment except that the mixture was replaced with a mixture with 5 mol parts of MnTiO ₃ (sample No. 66), and the characteristics were measured by the same method as in the first embodiment. However, the results shown in the following Table 15 were obtained.

Table 15 Sample No. ε tan δ (%) IR (MΩ) Yield index 61 51 × 10 ³ 0.7 17 × 10 ⁴ 0.04 62 52 × 10 ³ 0.7 17 × 10 ⁴ 0. 05 63 50 × 10 ³ 0.7 17 × 10 ⁴ 0.06 64 50 × 10 ³ 0.8 16 × 10 ⁴ 0.06 65 51 × 10 ³ 0.7 18 × 10 ⁴ 0.066 66 48 × 10 ³ 0.7 17 × 10 ⁴ 0.06

As is clear from the comparison between Table 5 and Table 10 showing the conventional example, Cu, Pb, Bi, M, and Mn were mixed even when a plurality of types of titanates of Cu, Pb, Bi, and Mn were mixed.
n is suppressed, the yield index becomes less than the conventional value,
The same functions and effects as those of the first and sixth to ninth embodiments are obtained.

[0053]

To the eleventh embodiment of] Instead of CuZrO ₃ of the first embodiment, the use of Cusio ₃ is a silicate of Cu C
In order to confirm that the same operation and effect as uZrO ₃ can be obtained, CuZrO ₃ in
Samples Nos. 67, 68, and 69 were prepared in the same manner and in the same manner as in the first embodiment except that the mole parts, 0.50 mole parts, 1.00 mole parts, and 3.00 mole parts of CuSiO ₃ were used. ,
When a capacitor of No. 70 was manufactured and its characteristics were measured by the same method as in the first embodiment, the results shown in the following Table 16 were obtained.

Table 16 Sample No. ε tan δ (%) IR (MΩ) Yield index 67 41 × 10 ³ 1.2 22 × 10 ⁴ 0.05 68 51 × 10 ³ 0.8 18 × 10 ⁴ 0. 05 69 50 × 10 ³ 0.8 19 × 10 ⁴ 0.06 70 46 × 10 ³ 1.1 17 × 10 ⁴ 0.06

As is clear from the comparison between Table 16 and Table 2 of the conventional example, according to the samples Nos. 67 to 70 according to the present invention,
The evaporation of Cu is suppressed in the same manner as in the first embodiment, the yield index becomes equal to or less than the conventional value, and the same operation and effect as in the first embodiment can be obtained.

[0056]

Instead of CuZrO ₃ of the twelfth embodiment A first embodiment, Pb To confirm that the same effects as CuZrO ₃ be used PbSiO ₃ is a silicate (Pb) is obtained In the first embodiment, 0.05 mol part, 0.50 mol part, 1.00 mol part of CuZrO ₃ in the first embodiment,
Samples Nos. 71 and 7 were prepared in the same manner and in the same manner as in the first embodiment except that 3.00 mol parts of PbSiO ₃ were used.
2, 73 and 74 were made and the characteristics were measured by the same method as in the first embodiment. The results shown in the following Table 17 were obtained.

Table 17 Sample No. ε tan δ (%) IR (MΩ) Yield index 71 41 × 10 ³ 1.2 24 × 10 ⁴ 0.06 72 43 × 10 ³ 0.7 22 × 10 ⁴ 0. 06 73 41 × 10 ³ 0.7 19 × 10 ⁴ 0.067 ⁴ 42 × 10 ³ 1.0 20 × 10 ⁴ 0.07

As is clear from the comparison between Table 17 and Table 4 showing the conventional example, according to the samples Nos. 71 to 74 according to the present invention, the evaporation of Pb was suppressed similarly to the Cu of the first embodiment. , The yield index becomes equal to or less than the conventional value, and the same operation and effect as those of the first and second embodiments can be obtained.

[0059]

Thirteenth Embodiment It is confirmed that the same function and effect as CuZrO ₃ can be obtained by using Bi ₄ Si ₃ O ₁₂ which is a silicate of Bi instead of CuZrO ₃ of the first embodiment. For this reason, CuZrO ₃ in the first embodiment is set to 0.
05 mol parts, 0.50 mol parts, 1.00 mol parts, 3.0
Samples Nos. 75 and 7 were prepared in the same manner and in the same manner as in the first embodiment, except that 0 mol parts of Bi ₄ Si ₃ O ₁₂ were used.
6, 77 and 78 were made and their characteristics were measured in the same manner as in the first embodiment. The results shown in the following Table 18 were obtained.

Table 18 Sample No. ε tan δ (%) IR (MΩ) Yield index 75 40 × 10 ³ 1.0 20 × 10 ⁴ 0.05 76 43 × 10 ³ 0.8 20 × 10 ⁴ 0. 06 77 43 × 10 ³ 0.7 21 × 10 ⁴ 0.06 78 40 × 10 ³ 1.0 21 × 10 ⁴ 0.06

As is clear from the comparison between Table 18 and Table 6, according to the samples Nos. 75 to 78 according to the present invention, the evaporation of Bi was suppressed as in the case of Cu of the first embodiment, and the yield index was increased. Is less than the conventional value, and the same operation and effect as those of the first and third embodiments can be obtained.

[0062]

To the fourteenth embodiment of] Instead of CuZrO ₃ of the first embodiment, the use of MnSiO ₃ is a silicate of Mn C
In order to confirm that the same operation and effect as uZrO ₃ can be obtained, CuZrO ₃ in
Molar parts, 0.50 part by mol 1.00 mol part, sample 3.00 molar parts other replaced with MnSiO ₃ of the first embodiment the same composition as and the same methods NO. 79,80,81 ,
When the capacitors of No. 82 were manufactured and their characteristics were measured by the same method as in the first embodiment, the results shown in the following Table 19 were obtained.

Table 19 Sample No. ε tan δ (%) IR (MΩ) Yield index 79 48 × 10 ³ 0.9 19 × 10 ⁴ 0.05 80 51 × 10 ³ 0.8 17 × 10 ⁴ 0. 05 81 48 × 10 ³ 0.8 21 × 10 ⁴ 0.05 82 48 × 10 ³ 1.0 20 × 10 ⁴ 0.06

As is clear from the comparison between Table 19 and Table 8, according to the samples Nos. 79 to 82 according to the present invention, the evaporation of Mn was suppressed as in the case of Cu of the first embodiment, and the yield index was reduced. Is less than the conventional value, and the same operational effects as those of the first and fourth embodiments can be obtained.

[0065]

Fifteenth Embodiment CuSiO of the eleventh to fourteenth embodiments
_Three, PbSiO_Three, Bi_FourSi_ThreeO₁₂, MnSiO_Threeof
Alternatively, adding a plurality of types selected from these
The same operational effects as in the eleventh to fourteenth embodiments can be obtained.
In order to confirm that CuZrO of the first embodiment_ThreeTo
0.5 mol part of CuSiO_ThreeAnd 0.5 mol part of PbSi
O_Three(Sample No. 83), 0.5 mol part of Cu
SiO_ThreeAnd 0.5 mole parts Bi _FourSi_ThreeO₁₂Mixture with
(Sample No. 84), 0.5 mol part of CuSiO_ThreeAnd 0.
5 mole parts MnSiO_Three(Sample No. 85)
0.5 mol part of PbSiO_ThreeAnd 0.5 mole parts Bi_FourS
i_ThreeO₁₂(Sample No. 86), 0.5 mol part
PbSiO_ThreeAnd 0.5 mol part of MnSiO_ThreeMixture with
(Sample No. 87), 0.5 mol part Bi_FourSi_ThreeO₁₂When
0.5 mol part of MnSiO_Three(Sample No. 8)
8) The same composition and the same as the first embodiment except that
Make a capacitor by one method, and use the same method as in the first embodiment.
When the characteristics were measured by the method, the results in the following Table 20 were obtained.
Was.

Table 20 Sample No. ε tan δ (%) IR (MΩ) Yield index 83 50 × 10 ³ 0.6 18 × 10 ⁴ 0.05 84 51 × 10 ³ 0.7 18 × 10 ⁴ 0. 05 85 51 × 10 ³ 0.6 18 × 10 ⁴ 0.07 86 51 × 10 ³ 0.7 18 × 10 ⁴ 0.06 87 50 × 10 ³ 0.7 19 × 10 ⁴ 0.07 88 48 × 10 ³ 0.8 19 × 10 ⁴ 0.06

As is clear from the comparison between Tables 20 and 9, even when a plurality of types of silicates of Cu, Pb, Bi and Mn are added, evaporation of Cu, Pb, Bi and Mn is suppressed. As a result, the yield index becomes equal to or less than the conventional value, and the same operation and effect as in the first embodiment can be obtained.

[0068]

The present invention sixteenth embodiment of To confirm the applicability to ceramic varistor element having both a capacitor function and a varistor function, SrTiO ₃ 100 molar parts CaTiO ₃ 10 molar parts Y ₂ O ₃ 0.6 mole A mixture having a composition of 0.05 parts to 3.00 parts by mole of CuTiO _{3 and} 0.2 parts by mole of SiO ₂ was prepared. It should be noted that CuTiO ₃ was added in an amount of 0.1.
05 mol parts, 0.50 mol parts, 1.00 mol parts, 3.0
Samples No. 89, 90, 91, which were changed to 0 mole parts in four stages,
Ninety-two samples were prepared. Next, the mixture of each sample was molded and fired in the same manner as in the first embodiment to obtain a semiconductor porcelain. Next, a paste consisting of Na ₂ O and an organic binder is applied to the semiconductor ceramic of each sample, which are are in the furnace 1100 ° C. in air for 2 hours heat diffusion treatment, the semiconductor crystal grains each other by Na ₂ O Was tightly bound. Next, a pair of electrodes were formed in the same manner as in the first embodiment to complete the varistor element.

Next, a yield index (V1m standard deviation / V1m standard deviation / V1m) indicating the variation of the varistor electrode V1m and the varistor voltage V1m of each sample.
V1m), the nonlinear coefficient α, and the energy tolerance. Here, the varistor electrode V1m is a voltage between the pair of electrodes when 1 mA flows between the pair of electrodes of the varistor element. The voltage nonlinear coefficient α was obtained by the following equation based on the voltage V1m between the pair of electrodes when 1 mA was passed through the varistor element and the voltage V10m between the pair of electrodes when 10 mA was passed through the varistor element. α = 1 / {log (V10m / V1m)} The energy tolerance E is expressed as follows.
Applied to the varistor element, and the change rate of the varistor voltage is 5%
The voltage V within the range was determined and determined by the following equation. E = 1/2 (CV ² ) (joul) Table 21 below shows the measurement results of Samples Nos. 89 to 92.

Table 21 Sample No. V1m Yield index α E (joul) 89 33.2 0.045 10.78 13.5 90 29.8 0.054 10.85 12.5 91 31.5 0.062 11.22 16.0 92 30.8 0.065 10.89 13.0

[0071] Sample NO. For comparison with the 89 to 92, the sample NO. Other Using CuO in accordance with the prior art instead of CuTiO ₃ in 89 to 92 samples NO. 89 to 92 sample NO in the same manner as . 93, 94, 95 and 96 varistor elements were formed and the characteristics were measured by the same method.
The following results in Table 22 were obtained.

Table 22 Sample No. V1m Yield index α E (joul) 93 28.3 0.090 10.02 7.2 94 26.5 0.102 10.25 8.0 95 27.2 0.100 10.55 8.3 96 26.9 0.098 10.36 8.0

As is clear from the comparison between Tables 21 and 22, according to Samples Nos. 89 to 92, the evaporation of Cu was suppressed, and the varistor voltage V1m and the energy withstand E were lower than those of Sample Nos. 89 to 89.
Higher than 92. Further, the yield index of the varistor voltage, that is, the variation is reduced.

[0074]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) The main component is not limited to SrTiO ₃ and SrCaTiO ₃ , but ABO ₃ (where A is Sr, Ca, Ba, M
One or more elements of g, and B is one or more elements of Ti and Zr) may be a titanium-strontium-based component. (2) As a semiconducting agent (valence controlling agent), Y ₂ O
Instead of or in addition to ₃ , Nb (niobium), W (tungsten), Ta (tantalum) and rare earth elements (La,
Ce, Pr, Nd, Sm, Dy, Pm, Eu, Gd, T
b, Ho, Er, Tm, Yb, Lu, etc. (for example, La ₂ O ₅ , WO ₃ , Ta ₂ O ₅ , CeO ₂ , Nd)
₂ O ₃ , Sm ₂ O ₅ , Pr ₆ O ₁₁ , Dy ₂ O ₃ etc.)
One or more species are preferably 0.1 to 100 mol parts of SrTiO ₃ or the main component consisting of the above-mentioned ABO _3.
It can be used in the range of 5.0 mole parts. (3) Al ₂ O ₃ as a sintering aid for porcelain materials,
One or more kinds selected from SiO ₂ , CuO, MnO ₂ , and Ag ₂ O are preferably used in an amount of 0.05 mol% based on 100 mol parts of SrTiO ₃ or the main component composed of ABO ₃ described above.
It can be added in the range of 0.50 mol part. (4) grain boundary insulation agent to Cu, Pb, Bi, zirconates of Mn, titanates, be a plurality of types of combinations of the silicate, and Bi ₂ O ₃ to such, Pb ₃ O ₄ , B ₂
O ₃ , MnO ₂ , CuO, Tl ₂ O ₃ , Sb ₂ O ₅ , F
One or more selected from metal oxides such as e ₂ O ₃ can be added. (5) Not limited to zirconate, titanate, and silicate of Cu, Pb, Bi, and Mn, but evaporated by firing in a valence controlling agent, a grain boundary insulating agent, or a sintering aid. Easier substances can be used as zirconates, or titanates, or silicates. (6) When the valence controlling agent or the sintering aid is a zirconate, a titanate, or a silicate according to the present invention, after the sintering without adding a grain boundary insulating agent to the porcelain material, MnO, CuO, Bi ₂ O ₃ ,
A paste of a metal oxide such as PbO can be applied and thermally diffused. (7) The present invention can also be applied to a case where a laminate obtained by printing a conductive paste on a porcelain green sheet (raw sheet) and sintering it to produce a multilayer capacitor or a varistor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a capacitor in principle.

[Explanation of symbols]

 2 Crystal particle 3 Grain boundary layer 4, 5 Electrode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01G 4/12

Claims (3)

(57) [Claims] 1. ABO ₃ (where A is Sr, Ba, C
a, one or more of Mg, B is T
O represents one or more of i and Zr, and O represents oxygen. A) forming a molded body containing a main component or a raw material capable of obtaining the main component, a valence controlling agent, and a grain boundary insulating agent; and baking the molded body in a reducing atmosphere. A step of performing heat treatment in an oxidizing atmosphere, wherein at least one of the grain boundary insulating agents is zirconate, titanate, or silicate. Method. 2. ABO ₃ (where A is Sr, Ba, C
a, one or more of Mg, B is T
O represents one or more of i and Zr, and O represents oxygen. A) forming a molded body containing a main component or a raw material from which the main component can be obtained, and a valence controlling agent; and baking the molded body. A method for producing a semiconductor porcelain, characterized in that at least one of the valence controlling agents is zirconate, titanate or silicate. 3. ABO ₃ (where A is Sr, Ba, C
a, one or more of Mg, B is T
O represents one or more of i and Zr, and O represents oxygen. A) a step of forming a molded body containing a main component or a raw material capable of obtaining the main component, a valence controlling agent, and a sintering aid; and baking the molded body. In the manufacturing method, at least one of the sintering aids is a zirconate, a titanate, or a silicate.