JPH08124781A - Manufacture of semiconductor ceramic - Google Patents

Abstract

PURPOSE: To reduce variation of characteristics by adding metal zirconate or titanate or silicate to grain boundary insulating agent easy to evaporate or valence control agent or sintering auxiliary. CONSTITUTION: A molded object is formed which contains the following; main componet composed of ABO3 (A is a one kind of element or a plurality of kinds of elements out of Sr, Ba, Ca and Mg, B is one kind or a plurality of kinds of elements out of Ti and Zr, and O represents oxygen) or material capable of obtaining the main component, valence control agent, and grain boundary insulating agent. The molded object is baked in a reducing atmosphere, and then heat-treated in an oxidizing atmosphere. At least one kind out of the grain boundary insulating agents is zirconate or titanate or silicate. Thereby the method of manufacturing semiconductor porcelain can be obtained which restains the evaporation of additive, and can reduce variation of characteristics.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Semiconductor porcelain containing SrTiO ₃ as a main component is widely used as a body of capacitors, varistors, thermistors and the like. One which such a method of manufacturing a semiconductor porcelain, the main component consisting of SrTiO _3, Nb, T
a, a valence control 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, Mn, SiO ₂ , Al ₂ O ₃ , MnO ₂ or the like. A mixture to which a sintering aid is added is prepared, this molded body is formed, and this molded body is fired in a reducing atmosphere at 1350 to 1450 ° C. for about 2 hours, and then in the air for insulation of crystal grain boundaries. 950 to 1200 ° C. for about 2 hours.

[0003]

By the way, Cu, Bi, as a valence control agent, a grain boundary insulating agent, or a sintering aid,
Oxides such as Pb and Mn evaporate during firing in a reducing atmosphere or heat treatment in an oxidizing atmosphere. Then, this evaporation amount changes according to variations in 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.

Therefore, an object of the present invention is to provide a method of manufacturing a semiconductor porcelain capable of suppressing evaporation of an additive and reducing variations in characteristics.

[0005]

The present invention for attaining the above-mentioned object provides ABO ₃ (where A is Sr, Ba, Ca,
Any one or more of Mg, B is Ti,
Any one or more elements of Zr, O represents oxygen. A main component consisting of or a raw material capable of obtaining the main component, a valence controller and a grain boundary insulating agent, a step of forming a compact, and a step of firing the compact in a reducing atmosphere, A method for manufacturing a semiconductor ceramic including a step of performing heat treatment in an oxidizing atmosphere, wherein the at least one grain boundary insulating agent is a zirconate, a titanate, or a silicate. is there. As described in claim 2, a valence control agent (for example, B
i, Mn) can be zirconates or titanates or silicates. 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 in the present invention can be obtained is, for example, SrTiO ₃
To obtain SrCO ₃ and TiO ₂ , (SrCa) Ti
SrCO ₃ , CaCO ₃ and TiO ₂ to obtain O ₃ .
Examples are BaCO ₃ and TiO ₂ for obtaining BaTiO ₃ . The valence control agent (semiconductor agent) is one or more compounds of Nb (niobium), Ta (tantalum), W (tungsten) and rare earth elements (Y, La, Ce, etc.). Examples of the metal functioning 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.
It is nZnO ₃ . Further, titanate is, for example, CuTi.
O ₃ , PbTiO ₃ , Bi ₄ Ti ₃ O ₁₃ , MnTiO ₃
Is. The silicate may be CuSiO ₃ , PbS, etc.
iO ₃ , Bi ₄ Si ₃ O ₁₂ , and MnSiO ₃ . The preferable ratio of each component of the semiconductor porcelain is as follows. Main component 100 mol parts Semiconducting agent 0.1 to 5.0 mol parts Grain boundary insulating agent 0.05 to 5.0 mol parts Firing in a reducing atmosphere is preferably 1300 to 1500 ° C.
It takes 1 to 5 hours. The heat treatment in an oxidizing atmosphere is preferably 700 to 1200 ° C. for 1 to 5 hours.

[0006]

According to the invention of each claim, a grain boundary insulating agent, a valence control agent, or a sintering aid, which easily evaporates, is added as a metal zirconate or titanate or silicate. If so, evaporation is less than that in the case of adding with a conventional metal oxide. That is, since zirconate, titanate, or silicate contains zircon or titanium or silicon that can stably exist at the grain boundaries and can also form a solid solution with the main component, they are combined with them. Metals also exist stably at the grain boundaries, and their evaporation is reduced. Further, since the metal is difficult to separate from zircon (Zr), titanium (Ti), or silicon (Si), this evaporation is suppressed. Therefore, even if the firing condition or the heat treatment condition changes, the change in the amount of the additive is reduced, and the variation in the characteristics is reduced. Further, since the evaporation is suppressed, the target characteristic can be obtained.

[0007]

[First Embodiment] Next, a method of 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 , A 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 control agent
Cu Zr, which is a zirconate of O ₃ (yttrium oxide) and Cu (copper) that mainly functions as a grain boundary insulating agent
O ₃ and SiO ₂ as a sintering aid are mixed with SrTiO ₃ 100 parts by mole Y ₂ O ₃ 0.6 parts by mole CuZrO ₃ 0.05 to 3.00 parts by mole SiO ₂ 0.2 parts by mole. And prepare them with a ball mill.
The mixture was wet-mixed for an hour and then dried to obtain a powder of the raw material mixture. CuZrO ₃ was changed to four stages of 0.05 parts by mole, 0.50 parts by mole, 1.00 parts by mole, and 3.00 parts by mole, and four kinds of samples No. 1 to NO. 4 were prepared.

Next, 10% by weight of an aqueous solution of polyvinyl alcohol as an organic binder was added to and mixed with the raw material mixture of each sample and granulated, and the granulated product was molded at a pressure of 1 ton / cm ² A disk-shaped molded body having a thickness of 10 mm and a thickness of 0.5 mm was obtained. Next, this molded body is put into a furnace and the volume ratio thereof is N.
1350 to 1450 in N ₂ + H ₂ mixed gas atmosphere (non-oxidizing atmosphere or reducing atmosphere) of ₂ : H ₂ = 99: 1
After firing for 2 hours at 0 ° C., heat treatment was performed in the air (oxidizing atmosphere) at 950 to 1200 ° C. for 2 hours to form an insulating layer at the crystal grain boundary, and the semiconductor porcelain of each sample was completed. The diameter of the sintered semiconductor porcelain was about 8 mm and the thickness was about 0.4 mm. The semiconductor ceramic 1 can be represented by the semiconductor crystal grains 2 and the grain boundary insulating layer 3 as schematically shown in FIG. 1.

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 baked at 800 ° C. for 1 hour in the atmosphere to form a pair of electrodes 4.
5 was formed and the capacitor was completed. In addition, 100 capacitors of the same structure were made for each sample in order to examine the variation in the characteristics.

Next, the apparent permittivity (ε), the dielectric loss (tan δ), the insulation resistance (IR) and the yield index (variation) of the apparent permittivity ε of the capacitors of the respective samples were measured.
The results shown in Table 1 below were obtained. The apparent permittivity ε and the dielectric loss tan δ are 25 ° C., frequency 1 kHz, voltage 1 V.
It was measured under the conditions. The insulation resistance IR was measured after applying DC 50V for 1 minute at 25 ° C. The yield index was calculated according to the following formula.

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

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 sample Nos. 1 to 4 was used.
CuO, which is a conventional additive, is replaced with 0.0 instead of ZrO _3.
5 mol parts, 0.50 mol parts, 1.00 mol parts, 3.00
The capacitors of Sample Nos. 5, 6, 7, and 8 were made by the same composition and the same method as those of Sample Nos. 1 to 4 except that the molar parts were changed, and the characteristics were measured by the same method. Two results were obtained.

Table 2 Sample No. ε tan δ (%) IR (MΩ) Yield index 5 42 × 10 ³ 1.2 20 × 10 ⁴ 0.07 6 45 × 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 Sample Nos. 1 to 8, C before firing was used.
When the ratio of the amount of u (copper) to the amount of Cu after firing and oxidation heat treatment was determined, it was 8 for sample Nos. 1 to 4 according to the present invention.
The sample No. 5 to 8 of the comparative example has a ratio of 0 to 90%, and the ratio is 65 to 75%. According to the method of the present invention, the scattering or evaporation of Cu during firing and oxidation heat treatment is higher than that in the conventional case. There were few.

As is clear from the comparison between Tables 1 and 2, the yield index of sample Nos. 1 to 4 according to the present invention is smaller than the yield index of sample Nos. 5 to 8 showing the comparative example. Such a small yield index means that there is little variation in ε. According to the present invention, the variation of ε becomes small because
C that is difficult to evaporate without adding Cu as this oxide
This is because CuZrO ₃ which is a zirconate of u was added. When the variation of ε is reduced, the yield rate of the capacitors, that is, the yield is improved, and the cost can be reduced. Further, since the evaporation of Cu is suppressed in the sample Nos. 1 to 4, ε, tan δ, and IR are the same as or better than those of the sample Nos. 5 to 8.

[0018]

[Second Embodiment] Even if PbZrO ₃ which is a zirconate salt of Pb (lead) is used instead of CuZrO ₃ , CuZr
In order to confirm that the same effects as O ₃ can be obtained, CuZrO ₃ in the first embodiment is added in an amount of 0.05 mol parts, 0.50 mol parts, 1.00 mol parts, and 3.00 mol parts of PbZrO 3. _When capacitors Nos. 9, 10, 11 and 12 having the same composition and the same method as those in the first embodiment were prepared and the characteristics were measured by the same method as in the first embodiment, except that the capacitors were replaced by The results shown in Table 3 below were obtained.

Table 3 Sample No. ε tan δ (%) IR (MΩ) Yield index 9 43 × 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 parts by mole 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 parts by mole, 1.00 parts by mole, and 3.00 parts by mole were added.
Make capacitors Nos. 3, 14, 15 and 16 and sample No. 9
When the characteristics were measured by the same method as that of ~ 12, the following Table 4
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 Tables 3 and 4,
According to the sample Nos. 9 to 12 according to the present invention, the evaporation of Pb was suppressed similarly to the Cu of the first embodiment, and the retention index became equal to or lower than the conventional value, and the same effect as that of the first embodiment was obtained. The effect is obtained.

[0023]

Third Embodiment Instead of CuZrO _{3 in} the first embodiment, Bi ₄ Zr which is a zirconate salt of Bi (bismuth) is used.
_In order to confirm that the same effect as CuZrO ₃ of the first embodiment can be obtained by using ₃ O ₁₂ , 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 by 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 Table 5 below were obtained.

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

Further, in order to compare with sample Nos. 17 to 20, conventional Bi ₂ O ₃ was used in place of Bi ₄ Zr ₃ O ₁₂ .
05 parts by mole, 0.50 parts by mole, 1.00 parts by mole, 3.0
When capacitors of Sample Nos. 21, 22, 23, and 24 were made by the same method as Sample Nos. 17 to 20 except that 0 mol part was added, and the characteristics were measured by the same method as Samples No. 17 to 20, The results shown in Table 6 below were obtained.

Table 6 Sample No. ε tan δ (%) IR (MΩ) Yield index 21 40 × 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 in the first embodiment, the yield index becomes equal to or lower than the conventional value, and the same effect as in the first embodiment is obtained. The effect is obtained.

[0028]

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

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 instead of MnZrO ₃ was used.
0.05 part, 0.50 part, 1.00 part,
The capacitors of Sample Nos. 29, 30, 31, and 32 were made in the same manner as Sample Nos. 25 to 28 except that 3.00 parts by mol were added, and the characteristics were measured in the same manner as Samples No. 25 to 28. However, the results shown in Table 8 below were obtained.

Table 8 Sample No. ε tan δ (%) IR (MΩ) Yield index 29 48 × 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 like the Cu of the first embodiment, the yield index becomes equal to or less than the conventional value, and the same action as that of the first embodiment is obtained. The effect is obtained.

[0033]

[Fifth Embodiment] CuZrO ₃ of the first to fourth embodiments,
In place of PbZrO ₃ , Bi ₄ Zr ₃ O ₁₂ , and MnZrO ₃ , a plurality of types selected from these may be added
In order to confirm that the same effect as in the fourth embodiment can be obtained, CuZrO ₃ of the first embodiment is mixed with 0.5 mol parts of CuZrO ₃ and 0.5 mol parts of PbZrO ₃ ( Sample No. 33), a mixture of 0.5 parts by mole of CuZrO ₃ and 0.5 parts by mole 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. Mixture with ₁₂ (Sample No. 36), 0.5 mol part of PbZrO
₃ and 0.5 mol part of MnZrO ₃ (Sample NO.
37), having the same composition and the same composition as in the first example, except that it 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). When a capacitor was produced by the method and the characteristics were measured by the same method as in the first embodiment, the results shown in Table 9 below were obtained.

Table 9 Sample No. ε tan δ (%) IR (MΩ) Yield index 33 51 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 5 52 × 10 ³ 0.8 19 × 10 ⁴ 0.04 38 46 × 10 ³ 0.6 21 x 10 ⁴ 0.06

Further, in order to compare with sample Nos. 33 to 38, the zirconates of Cu, Pb, Bi, and Mn of sample Nos. 33 to 38 were replaced with these oxides, and sample NO.
In the same manner as 33 to 38, sample Nos. 39, 40, 41,
42, 43, 44 capacitors were made and sample No. 33-
When the characteristics were measured by the same method as in No. 38, the following Table 10
Was obtained.

Table 10 Sample No. ε tan δ (%) IR (MΩ) Yield index 39 50 × 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 0.09 44 48 × 10 ³ 0.8 17 x 10 ⁴ 0.10

As is clear from the comparison between Table 9 and Table 10, according to the sample Nos. 33 to 38 according to the present invention, Cu,
Even if a plurality of types of zirconate salts of Pb, Bi, and Mn are added, the evaporation of Cu, Pb, Bi, and Mn is suppressed, and the retention index becomes less than the conventional value. The same effect can be obtained.

[0038]

[Sixth Embodiment] In order to confirm that the same action and effect as CuZrO ₃ can be obtained by using CuTiO ₃ which is a titanate of Cu in place of CuZrO ₃ of the first embodiment, CuZrO ₃ in Example 1 was 0.0
5 mol parts, 0.50 mol parts, 1.00 mol parts, 3.00
Sample Nos. 45, 46, 4 having the same composition and the same method as in the first embodiment except that CuTiO ₃ in the molar part was replaced.
When capacitors Nos. 7 and 48 were produced and the 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 the sample Nos. 45 to 48 according to the present invention, the sample N
Evaporation of Cu is suppressed similarly to the case of using CuO of O.5 to 8 as in the first embodiment, and the yield index becomes equal to or lower than the conventional value, and the same effect as the first embodiment. Is obtained.

[0041]

[Seventh Embodiment] In order to confirm that the same effect as CuZrO ₃ can be obtained by using Pb (lead) titanate PbTiO ₃ instead of CuZrO _{3 in} the first embodiment. In addition, 0.05 mol parts, 0.50 mol parts, 1.00 mol parts of CuZrO ₃ in the first embodiment,
Sample No. 49, 5 having the same composition and the same method as in the first embodiment except that PbTiO ₃ was replaced by 3.00 parts by mol.
When capacitors Nos. 0, 51 and 52 were made and the characteristics were measured by the same method as in the first embodiment, the results shown in Table 12 below were obtained.

Table 12 Sample NO. Ε tan δ (%) IR (MΩ) Yield index 49 41 × 10 ³ 1.2 22 × 10 ⁴ 0.06 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 the sample Nos. 49 to 52 according to the present invention, the sample N
Compared with the case of PbO of O.13 to 16, the evaporation of Pb is suppressed similarly to Cu of the first embodiment, the retention index becomes less than the conventional value, and it is the same as that of the first and second embodiments. The effect of is obtained.

[0044]

[Eighth Embodiment] Bi which functions as a grain boundary insulating agent and a valence control agent instead of CuZrO _{3 in} the first embodiment
To confirm that Bi ₄ Zr ₃ O ₁₂ which is a titanate of (bismuth) is used, the same effect as CuZrO ₃ can be obtained, and CuZrO ₃ in the first embodiment is used.
0.05 part, 0.50 part, 1.00 part,
Sample No. 5 having the same composition and the same method as in the first embodiment except that Bi ₄ Zr ₃ O ₁₂ was replaced with 3.00 parts by mol.
When capacitors Nos. 3, 54, 55 and 56 were made and the characteristics were measured by the same method as in the first embodiment, the results shown in the following Table 13 were obtained.

Table 13 Sample No. ε tan δ (%) IR (MΩ) Yield index 53 42 42 × 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 sample Nos. 53 to 56 according to the present invention, the evaporation of Bi is the first operation as compared with the case of Bi ₂ O _{3 in} Table 6. It is suppressed similarly to Cu of the example, the yield index becomes equal to or less than the conventional value, and the same effects as those of the first and third embodiments can be obtained.

[0047]

[Ninth Embodiment] Even if CuZrO ₃ which is a titanate of Mn functioning as a grain boundary insulating agent and a sintering aid is used instead of CuZrO ₃ of the first embodiment, CuZrO ₃ is used.
In order to confirm that the same action and effect as above can be obtained, 0.05 mol part of CuZrO ₃ in the first embodiment,
0.50 parts by mole, 1.00 parts by mole, 3.00 parts by mole of M
Capacitors of sample Nos. 57, 58, 59 and 60 were made by the same composition and the same method as those of the first embodiment except that they were replaced by nTiO ₃ , and the characteristics were measured by the same method as that of the first embodiment. However, the results shown in Table 14 below were obtained.

Table 14 Sample No. ε tan δ (%) IR (MΩ) Yield index 57 50 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 sample Nos. 57 to 60 according to the present invention, the evaporation of Mn is suppressed similarly to the Cu of the first embodiment, and the yield index. Is less than or equal to the conventional value, and the same 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 effects as those of the sixth to ninth embodiments can be obtained by adding a plurality of kinds selected from these, instead of CuZrO ₃ of the first embodiment, ．
5 mol parts of CuTiO ₃ and 0.5 mol parts of PbTiO ₃
With a mixture (Sample No. 61), 0.5 mol part of CuTi
A mixture of O ₃ and 0.5 parts by mole of Bi ₄ Ti ₃ O ₁₂ (sample NO. 62), a mixture of 0.5 parts by mole of CuTiO ₃ and 0.5 parts by mole 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 of Pb
A mixture of TiO ₃ and 0.5 part by mole of MnTiO ₃ (Sample No. 65), 0.5 part by mole of Bi ₄ Ti ₃ O ₁₂ and 0.
A capacitor was made with the same composition and method as in Example 1 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 Example 1. However, the results shown in Table 15 below 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 0.06 66 48 × 10 ³ 0.7 17 x 10 ⁴ 0.06

As is clear from the comparison between Table 5 and Table 10 showing the conventional example, even when a plurality of titanates of Cu, Pb, Bi and Mn are mixed, Cu, Pb, Bi and M are mixed.
The evaporation of n is suppressed, the yield index becomes below the conventional value,
The same effect as the first and sixth to ninth aspects can be obtained.

[0053]

Eleventh Embodiment Even if CuSiO ₃ which is a silicate of Cu is used instead of CuZrO ₃ of the first embodiment, C
In order to confirm that the same effect as uZrO ₃ can be obtained, CuZrO ₃ in the first embodiment is adjusted to 0.05%.
Sample Nos. 67, 68 and 69 having the same composition and the same method as those in the first embodiment except that CuSiO ₃ was replaced by 1 mol part, 0.50 mol part, 1.00 mol part and 3.00 mol part. ,
70 capacitors were manufactured and the characteristics were measured by the same method as in the first example, and the results shown in Table 16 below 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 apparent from the comparison between Table 16 and Table 2 of the conventional example, according to the sample Nos. 67 to 70 according to the present invention,
Evaporation of Cu is suppressed in the same manner as in the first embodiment, and the yield index becomes equal to or lower than the conventional value, and the same effect as 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 addition, 0.05 mol parts, 0.50 mol parts, 1.00 mol parts of CuZrO ₃ in the first embodiment,
Sample Nos. 71 and 7 having the same composition and the same method as those in the first embodiment except that PbSiO ₃ was replaced with 3.00 parts by mol.
When capacitors Nos. 2, 73 and 74 were made and the characteristics were measured by the same method as in the first embodiment, the results shown in Table 17 below were obtained.

Table 17 Sample NO. Ε tan δ (%) IR (MΩ) Yield index 71 41 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 0.06 74 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 sample Nos. 71 to 74 according to the present invention, the evaporation of Pb is suppressed similarly to Cu of the first embodiment. The yield index becomes equal to or lower than the conventional value, and the same effects as those of the first and second embodiments can be obtained.

[0059]

To the thirteenth embodiment of] Instead of CuZrO ₃ of the first embodiment, ensure that the same effects as CuZrO ₃ be used Bi ₄ Si ₃ O ₁₂ is a silicate of Bi is obtained Therefore, CuZrO ₃ in the first embodiment is added to 0.
05 parts by mole, 0.50 parts by mole, 1.00 parts by mole, 3.0
Sample Nos. 75 and 7 were prepared by the same composition and the same method as in the first embodiment except that 0 mol part of Bi ₄ Si ₃ O ₁₂ was replaced.
When capacitors Nos. 6, 77 and 78 were made and the characteristics were measured by the same method 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 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 sample 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. Is less than or equal to the conventional value, and the same effects as those of the first and third embodiments can be obtained.

[0062]

[Fourteenth Embodiment] Even if MnSiO ₃ which is a silicate of Mn is used in place of CuZrO ₃ of the first embodiment, C
In order to confirm that the same effect as uZrO ₃ can be obtained, CuZrO ₃ in the first embodiment is adjusted to 0.05%.
Sample Nos. 79, 80, 81 having the same composition and the same method as those in the first embodiment except that MnSiO ₃ of 0.5 parts, 0.50 parts, 1.00 parts and 3.00 parts were used. ,
No. 82 capacitor was manufactured and the characteristics were measured by the same method as in the first example, and the results shown in Table 19 below 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 sample Nos. 79 to 82 according to the present invention, the evaporation of Mn is suppressed similarly to the Cu of the first embodiment, and the yield index. Is less than or equal to the conventional value, and the same effects as those of the first and fourth embodiments can be obtained.

[0065]

[15th Embodiment] CuSiO of the 11th to 14th embodiments
₃, PbSiO₃, Bi_FourSi₃O₁₂, MnSiO₃of
Instead, even if you add multiple types selected from these,
The same effects as those of the 11th to 14th embodiments can be obtained.
In order to confirm the above, CuZrO of the first embodiment₃To
0.5 mol part of CuSiO₃And 0.5 mol part of PbSi
O₃With a mixture (sample NO. 83), 0.5 mol part of Cu
SiO₃And 0.5 mol part of Bi _FourSi₃O₁₂Mixture with
(Sample No. 84), 0.5 mol part of CuSiO₃And 0.
5 mol part of MnSiO₃Mixture with (Sample No. 85),
0.5 mol part of PbSiO₃And 0.5 mol part of Bi_FourS
i₃O₁₂With a mixture (Sample No. 86), 0.5 mol part
PbSiO₃And 0.5 mol part of MnSiO₃Mixture with
(Sample No. 87), 0.5 mol part of Bi_FourSi₃O₁₂When
0.5 mol part of MnSiO₃Mixture with (Sample No. 8
8) except that it has the same composition and the same composition as in the first embodiment.
The same method as in the first embodiment
When the characteristics were measured by the method, the results shown in Table 20 below were obtained.
Was.

Table 20 Sample No. ε tan δ (%) IR (MΩ) Yield index 83 50 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 x 10 ⁴ 0.06

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

[0068]

[Sixteenth Embodiment] In order to confirm that the present invention can be applied to a porcelain varistor element having both a capacitor function and a varistor function, SrTiO ₃ 100 mol part CaTiO ₃ 10 mol part Y ₂ O ₃ 0.6 mol part the parts CuTiO ₃ 0.05~3.00 molar parts mixture of the composition of SiO ₂ 0.2 parts by mole was prepared. In addition, CuTiO ₃ is less than 0.
05 parts by mole, 0.50 parts by mole, 1.00 parts by mole, 3.0
Sample Nos. 89, 90, 91, which were changed to 0 mol parts in 4 stages
92 samples were prepared. Next, the mixture of each sample was molded by the same method as in the first embodiment and fired 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 firmly bonded. Next, a pair of electrodes was formed in the same manner as in the first embodiment to complete the varistor element.

Next, the yield index (V1m standard deviation / V1m standard deviation / variation of the varistor electrode V1m and varistor voltage V1m of each sample is shown.
The average value of V1m), the non-linear coefficient α, and the energy tolerance were determined. Here, the varistor electrode V1m is the voltage between the pair of electrodes when 1 mA is applied between the pair of electrodes of the varistor element. The voltage non-linearity coefficient α was obtained by the following formula based on the voltage V1m between the pair of electrodes when 1 mA was applied to the varistor element and the voltage V10m between the pair of electrodes when 10 mA was applied. α = 1 / {log (V10m / V1m)} Energy tolerance E is 2 pulses of voltage V at 10 second intervals.
When applied to a rotating varistor element, the rate of change in varistor voltage is 5%
The voltage V that falls within the range was determined and determined by the following formula. E = 1/2 (CV ² ) (joul) The following Table 21 shows the measurement results of sample Nos. 89 to 92.

Table 21 Sample NO. V1m Retention 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

For comparison with Sample Nos. 89-92, Sample Nos. 89-92 were prepared in the same manner except that CuO 3 was used in accordance with the prior art instead of CuTiO ₃ in Samples Nos. 89-92. . 93, 94, 95, 96 varistor elements were formed and the characteristics were measured by the same method.
The results shown in Table 22 below were obtained.

Table 22 Sample NO. V1m Yield Index α E (joul) 93 28.3 0.090 10.02 7.2 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 the sample Nos. 89 to 92, the evaporation of Cu is suppressed, and the varistor voltage V1m and the energy withstand E are the values of the sample Nos. 89 to 89.
Higher than 92. Further, the yield index of the varistor voltage, that is, the variation becomes small.

[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, B is one or more elements of Ti and Zr), and may be a titanium strontium-based component. (2) As a semiconducting agent (valence control 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.) (eg, 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.) 1
One or more species is preferably 0.1 to 100 parts by mole of SrTiO ₃ or the above-mentioned ABO _{3 as a} main component.
It can be used in the range of 5.0 parts by mole. (3) Al ₂ O ₃ as a sintering aid for porcelain materials,
One or more selected from SiO ₂ , CuO, MnO ₂ and Ag ₂ O is preferably added to the main component consisting of 100 parts by mole of SrTiO ₃ or ABO ₃ mentioned above.
It can be added in the range of 0.50 mol part. (4) The grain boundary insulating agent is a combination of plural kinds of zirconates, titanates and silicates of Cu, Pb, Bi and Mn, and Bi ₂ O ₃ and 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 zirconates, titanates, and silicates of Cu, Pb, Bi, and Mn, evaporating by firing in a valence control agent, a grain boundary insulating agent, or a sintering aid. Easy substances can be used as zirconates or titanates or silicates. (6) When the valence control agent or the sintering aid is zirconate, titanate, or silicate according to the present invention, the grain boundary insulating agent is not added to the porcelain material, and after firing. On the surface of the semiconductor porcelain of MnO, CuO, Bi ₂ O ₃ ,
A metal oxide paste such as PbO can be applied and thermally diffused. (7) The present invention can be applied to a case where a porcelain green sheet (green sheet) on which a conductive paste is printed is laminated and fired to form a laminated capacitor or a varistor.

[Brief description of drawings]

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

[Explanation of symbols]

 2 Crystal grain 3 Grain boundary layer 4, 5 Electrode

Claims (3)

[Claims] 1. ABO ₃ (where A is Sr, Ba, C
a, element of one or more of Mg, B is T
Any one or more of i and Zr, O represents oxygen. A main component consisting of or a raw material capable of obtaining the main component, a valence control agent and a grain boundary insulating agent, a step of forming a compact, a step of firing the compact in a reducing atmosphere, A method of manufacturing a semiconductor porcelain having 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, element of one or more of Mg, B is T
Any one or more of i and Zr, O represents oxygen. In the method for manufacturing a semiconductor porcelain, the method further comprises the step of forming a molded body containing a valence control agent and a main component consisting of (4) or a raw material capable of obtaining the main component, and a step of firing the molded body. A method for producing a semiconductor porcelain, wherein at least one of the valency control agents is zirconate, titanate or silicate. 3. ABO ₃ (where A is Sr, Ba, C
a, element of one or more of Mg, B is T
Any one or more of i and Zr, O represents oxygen. Of a semiconductor porcelain having a step of forming a molded body containing a main component consisting of a) or a raw material capable of obtaining the main component, a valence control agent, and a sintering aid, and a step of firing the molded body. In the manufacturing method, at least one of the sintering aids is zirconate, titanate, or silicate, and the method for manufacturing a semiconductor porcelain.