JPH042105A - Grain-boundary insulation type semiconductor ceramic capacitor - Google Patents

Abstract

PURPOSE:To obtain a ceramic capacitor having a large effective dielectric constant by adding a grain-boundary depletion-layer forming agent to a perovskite type oxide mainly comprising strontium titanate, mixing and pressure-molding the whole, baking the molded form in a reducing atmosphere containing hydrogen, coating the surface of the baked substance with a grain-boundary diffusate containing bismuth oxide and forming an electrode through heat treatment in an oxidizing atmosphere. CONSTITUTION:A sintering accelerating additive (0.1-50wt.%), a semiconductor-change accelerating additive (0.05-2.0wt.%) and a grain-boundary depletion-layer forming agent (0.1-6.0wt.%) composed of Sr1-x-yBaxCay (Mn1/2Nb1/2)O3 are added to a perovskite type oxide mainly comprising strontium titanate, mixing-pressure molded, and baked at 1250-1500 deg.C in a reducing atmosphere containing hydrogen. The surface of the baked substance is coated with a grain-boundary diffusate containing bismuth oxide, and an electrode is formed through heat treatment at 850-1200 deg.C in an oxidizing atmosphere. Grain-boundary insulation type semiconductor ceramics 11 and a lead 13 are mounted on the electrode 12, thus acquiring a semiconductor ceramic capacitor having large grain-boundary insulating properties.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to grain boundary insulated semiconductor ceramic capacitors.

Conventional technology In recent years, by insulating the grain boundaries of this type of ceramic oxide semiconductor, it has become possible to obtain capacitor elements with a much larger effective permittivity than conventional ceramics and dielectrics. It has been known. For example, 5rTiO= is the main component, and Nb2O5 and TrO□-Alz(
Copper oxide (Cub) and bismuth oxide (Bias3) are diffused into the grain boundaries of a polycrystalline ceramic semiconductor obtained by adding an h-5tow mixture, molding, and sintering to form a depletion layer at the grain boundaries. The grain boundary insulated semiconductor capacitor obtained by forming electrodes by insulating the grain boundaries has a boost breakdown voltage of 1200 V/K, an insulation resistance of 1 x 10'MΩ/CI, and an effective dielectric constant of 20,000～
A large value like 100.000 has been changed. Note that here, Cub is a diffusion substance.

Regarding the role of Biass, CuO forms an electron trap center in the grain boundaries of the sintered body, and traps electrons in the crystal grains of the n-type semiconductor crystal near the grain boundaries. It functions to form a depletion layer without electrons near the grain boundaries. A grain boundary insulated semiconductor ceramic capacitor forms a capacitor by storing charge on both sides of the depletion layer thus formed. On the other hand, Biz(
h is known as a good conductor of oxygen along with ZrO□, etc., and it exists at the grain boundaries and functions to transport oxygen from the outside to the inside of the sintered body by diffusion and supply the oxygen necessary for the formation of grain boundary depletion layers. It is something.

Problems to be Solved by the Invention However, in order to obtain a large capacitance, grain boundary insulated semiconductor ceramic capacitors produced using such conventional manufacturing methods are made by making the crystal grains in the sintered body as large as possible and forming them into a paste-like structure. This method involves applying bismuth oxide containing copper oxide, etc., around the sintered body obtained by firing at a high temperature, and then applying heat treatment to diffuse old zOs, CuO, etc. into the inside of the sintered body. However, in the case of multilayer ceramic capacitors, the electrode spacing becomes narrow, so the grain size of the sintered body must be suppressed, and elements fabricated by conventional methods are
CuO tends to diffuse (damaged), so it tends to cause variations in properties, and thicker ones have a thickness of about 7 minutes (1 piece CuO).
Since it is difficult to diffuse the elements, there are problems such as restrictions on the size of the element.

Means for Solving the Problem In order to solve this problem, the present invention adds a sintering accelerating additive (0.1 to 5.01%) and a semiconducting accelerating additive to a perovskite-type oxide mainly composed of 5rTi03. agent (0,0
5-2. 0 wt%) and Sr1-X-? Bax
Ca.

(Mr++zz Nb+/z)O*, (0,1~6.0
wt%), or Sr1-x-F Ba, Ca,
(Cot/3 Nbz/5)Os, (O61~5.0w
t%), or 5r1-x-y BaXCay CC
u+ys Nbz73)01, (0,1~10.0w
After adding a grain boundary depletion layer forming agent consisting of (0≦x+y≦1), mixing, printing and molding, sintering at high temperature to make a semiconductor, 850% in an oxidizing atmosphere.
A grain boundary insulated semiconductor ceramic capacitor is obtained by performing a diffusion treatment of bismuth oxide or the like at ~1200'C.

Effect As mentioned above, at high temperatures, the perovskite-type oxide mainly composed of 5rTi03 and Sr+-
x-y Bax Cay (Mn+zz Nb+zz)
O:i or 5rI-x-yBa, Cay(CoIz
s Nbzzt) or Sr+-x-y Bah Ca
y (CIJ1/3 Nbz/3) and a semiconductor-promoting additive are reacted and dissolved in solid solution, and during the cooling process during firing, oxides containing copper are precipitated at the grain boundaries. The oxygen that has diffused through the diffused bismuth oxide further oxidizes grain boundary substances such as copper, forming electron trap centers at the grain boundaries, and forming grain boundaries within the low-resistance semiconductor crystal formed by reduction. A depletion layer is formed along the . The depletion layer thus obtained has good insulating properties, and charges are stored on both sides of the depletion layer, resulting in a high-quality capacitor.

In other words, the grain size of the crystal grains in the sintered body is small and uniform, and there is no need to apply or diffuse a grain boundary depletion layer forming agent such as copper oxide. A large, grain-boundary insulated semiconductor ceramic capacitor with good characteristics can be obtained simply by applying it, heat-treating it in air, and diffusing it.

Embodiment A grain boundary insulated semiconductor ceramic capacitor according to an embodiment of the present invention will be described based on the following embodiments. Note that FIG. 1 is a perspective view of a grain boundary insulated semiconductor capacitor, in which 1 is a grain boundary insulated semiconductor ceramic, 12 is an electrode, and 13 is a lead wire.

(Example 1) Titanylstrontium oxalate (SrTiO(CzOa)
)・4H,0) is added to strontium titanate (SrTiO3) obtained by thermal decomposition, and the sintering accelerator Ti0z-AhOs-
5i (h (ratio of 20:35:45)) from 0.05 to 6.
0 wt%, and 0.02 to 3.0 wt% of the semiconductor accelerator Nbzos.
0 wt%, grain boundary depletion layer forming agent Sr (Mn + yz
After adding 0.05 to 0 wt% of Nb+7z)O and mixing well, it was calcined at 900"C. After wet pulverization, it was dried, granulated, molded, and heated at 1400°C in the air. After sintering and wet pulverizing again, it was made into a paste using a resin and an organic solvent, and printed alternately with platinum paste for electrodes.
After hydrogen reduction at 00° C. and application of bismuth oxide, heat treatment was performed at 950° C. in the air, electrodes were adjusted, and electrical characteristics were measured. The measurement results are shown in Table 1.

In addition, the sintering accelerator Ti02-AlzO)-3iO□(2
0:35:45w) is a commercially available TiCl2
, A1□O:+, SiO□ powder at 20:35:
The basis weight was mixed at a weight ratio of 45, and calcined at 1200°C.
Obtained by crushing. Furthermore, a grain boundary depletion layer forming agent Sr (Mn+/z
Nb1yJO3 is commercially available 5rCO*, MnO, N
btOs was mixed, calcined at 900°C, and pulverized.

(Left below) Table 1 As is clear from Table 1, 0.1 to 5.0 wt of the sintering accelerator Ti0z-AIz03-5iO2 is added to 5rTiO+.
%, semiconductor accelerator NbzOs is 0.05-2.0wt
%, grain boundary depletion layer forming agent Sr (Mn+zz Nb+y□)
This material, which is obtained by adding 0.1 to 6.0 wt% of Os and firing, exhibits extremely excellent dielectric properties with a small Jan δ value, and can be used as a capacitor. That is, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well uniformed, and the diameter was 2.0.
~4.0 μ-, the dielectric loss was 1.0% or less, and the apparent dielectric constant was 2,000 or more. We also measured the temperature coefficient of capacitance, insulation resistance, boost breakdown voltage, and equal series resistance, and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 2) Commercially available industrial strontium titanate (SrTiOi)
5r04azOs system (e.g. 40:6ht ratio), T
iOz-MgO-3tCh system (e.g. 30:30:40
iit ratio), TiOz-MnO-SiO2 system (e.g. 10:50:40sit ratio), CaO-Mg0-Al
2O2-5iOt system (e.g. 30:10:15:45w
t ratio), TiO□-^hoz-3iO□ system (e.g. 2
0:35:45wt% ratio), Zn0-NbzOs-S
iO2 system (e.g. 50:45:5 wt% ratio), Z
rJ-MnO-3iO2 system (e.g. 10:55:35w
2.0 wt % of the sintering accelerator selected from t% ratio), 0.4 wt % of the semiconductor accelerator Ytos, and 0.05 to 8 wt % of the grain boundary depletion layer forming agent Sr(Mn+zz Nb+zz)Os.
After adding 0iit% and mixing well, it was calcined at 900"C. After wet grinding, it was dried, granulated and molded, and then heated at 1380"C in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen. After baking and coating with bismuth oxide, heat to 950°C in the atmosphere.
After heat treatment, electrodes were formed and electrical properties were measured. The measurement results are shown in Table 2. The sintering accelerator is, for example, T
iO, -MgO-3iOz (30:30:40wt ratio)
is commercially available (D Ti Ot, MgO, 5iOz (7)
Mix the powders at a weight ratio of 30:30:40,
The product was calcined at 00°C and pulverized. Further, a grain boundary depletion layer forming agent was obtained by mixing commercially available SrCO3°MnO and Nb105, calcining the mixture at 900°C, and pulverizing the mixture.

(As is clear from Table 2 in the margin below, TiOz2 is added to 5rTi03.
- A book obtained by adding 2.0 wt% of a sintering accelerator such as MgO-5in, 0.4 wt% of a semiconductor accelerator Y2O3, and 0.1 to 6.0 wt% of a grain boundary depletion layer forming agent and firing. The material exhibits excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well matched depending on the composition, ranging from 2.0 to 4.
At 0 μm, the dielectric loss was 1.0% or less and the apparent dielectric constant was 2.000 or more. Other capacitance temperature coefficients,
We measured insulation resistance, boosted breakdown voltage, equivalent series resistance, etc., and found satisfactory values. It should be noted that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 3) Commercially available industrial strontium titanate (SrTiO3)
Ti (h-MgO-5iOz system (e.g. 30:30:
4 (:ht ratio) of sintering accelerator of 4.0 wt%, between semiconductor accelerators, Nb, O,, Ta2's, La2O2,
Y2O3 to 1. Qwt%, grain boundary depletion layer forming agent Sr6.
* Baa, + Cao, + (Mn+zz Nb
+yz) Oz, Sro, aBa6. x Cao,s(
Adding 2.0 wt% of Mn+/z Nb+zz)Os,
After mixing well, the mixture was calcined at 900°C. After wet pulverization, it is dried, granulated, molded, and fired at 1380°C in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen. After coating with bismuth oxide, it is heat-treated at 950°C in the air to form an electrode. The electrical properties were measured. The measurement results are shown in Table 3.

Note that the sintering accelerator is, for example, TiOz-MgO-5iC.
h series (30:30:40w ratio) is commercially available Ti
The powders of O2, MgO, and 5iO1 were mixed in basis weight at a weight ratio of 30:30:40, calcined at 1200°C, and pulverized.

Further, grain boundary depletion layer forming agents include commercially available SrCO2, BaC0
,, MnO, and NbJs were mixed and calcined at 900°C.
Obtained by crushing.

It is clear from Table 3 (!: < , SrTiO3 NiT
4.0wt of sintering accelerator such as iO, -MgO5iO2
%, semiconducting accelerator Y20. The present material obtained by adding 1.0 wt % of aluminum and 2.0 wt % of a grain boundary depletion layer forming agent and firing it exhibits excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well matched for each composition and was 2 to 3 μ-, the dielectric loss was less than 1.0%, and the apparent dielectric constant was more than 2,000. . We also measured the temperature coefficient of capacitance, insulation resistance, boosted breakdown voltage, and equivalent series resistance, and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 4) Titanyl strontium oxalate (SrTiO(CaO4)
Strontium titanate (Sr-AhOs) obtained by thermal decomposition of 4H, O)
-3iOz (ratio 20:35:45-) from 0.05 to 6
．． 0 wt%, semiconductor accelerator Nb, o.

0.02 to 3.0 iet%, grain boundary depletion layer forming agent 5r
(Culz3Nb*z3)Ox from 0.05 to 6. 0w
After mixing thoroughly, the mixture was calcined at 900°C. After wet pulverization, drying, granulation, molding, and
Sintered at 0"C, wet-pulverized again, made into a base using resin and organic solvent, printed alternately with platinum paste for electrodes, hydrogenated at 1300°C, coated with bismuth oxide, and exposed to air. Heat treatment was performed at 950''C, and the electrodes were adjusted and electrical properties were measured. The measurement results are shown in Table 4.

In addition, the sintering accelerator TiO□-AIz03-5iO□(2
0:35:45wt ratio) is commercially available TiOz, Alt (
Powders of 5 iOz were mixed in basis weight at a weight ratio of 20:35:45, calcined at 1200°C, and pulverized. Furthermore, grain boundary depletion layer forming agent 5r (Cu+7s Nt+zz*)
0+ was obtained by mixing commercially available 5rCO, CuO, and Nb2O5, calcining at 900'C, and pulverizing.

As is clear from Table 4, the sintering accelerator Ti0z-Alz03-5i (h is 0.1 to 5.0wt) is added to 5rTi (h).
%, and the semiconducting accelerator NbzOs is 0.05 to 2. Qwt
%, grain boundary depletion layer forming agent 5rCCu+/s Nbzy3)
This material obtained by adding 0.1 to 5.0 wt% of Ox and firing it exhibits excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well aligned, ranging from 2.0 to 4.0μ■, the dielectric loss was less than 1.0%, and the apparent dielectric constant was more than 2,500. . We measured the temperature coefficient of its low capacitance, insulation resistance, boosted breakdown voltage, and equal series resistance, and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 5) Commercially available industrial strontium titanate (SrTi(h)
TiO, -MgO-5iOz system (e.g. 30:3
0:40w), TiO□-MnO-5iOz
system (e.g. 10:50:40wt ratio), CaO-Mg
0A1z03-5iO1 system (e.g. 30:10:15:
45wt ratio), Ti0l-AIzol-5iO1 system (
For example, 20:35:45st% ratio), Zn0-Nb*
03-5iOz system (e.g. 50:45:5 wt% ratio), ZrOzMnO-5iO2 system (e.g. 10:55
: 35wt% ratio).
After adding 0 wt%, 04-t% of semiconductor accelerator Y2O3, and 0.05 to 6.0 wt% of grain boundary depletion layer forming agent 5r(Cu+z:+Nbzz3)03 and mixing well, 9
It was calcined at 00°C. After wet pulverization, drying, granulation, and molding are carried out in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen.
It was fired at 80° C., coated with bismuth oxide, and then heat treated at 950° C. in the air to form electrodes and measure electrical properties. The measurement results are shown in Table 5.

Note that the sintering accelerator is, for example, TiO□-Mgo-sio
, system (30:30:40wt ratio) was commercially available Tie,
The powders of MgO and 5i02 were mixed in basis weight at a weight ratio of 30:30:40, calcined at 1200'C, and pulverized. Furthermore, grain boundary depletion layer forming agents include commercially available 5rCOz and Cu.
It was obtained by mixing O and NbzOs, calcining at 900°C, and pulverizing.

It is clear from Table 5 (, 5rTiOs has TiO□-
Sintering accelerator such as MgO3iO□ is added at 2.0 wt%, semiconductor formation accelerator A'l] yz O3 is added at 0.4 wt%, grain boundary depletion layer forming agent is added at 0.1 to 5, Qwt% and fired. The resulting material exhibits extremely excellent dielectric properties and can be used as a capacitor. In other words, as a result of microscopic observation, the fine particles of the sintered body have a uniform particle size depending on the composition.
．． In the range of 0 to 4.0 μm, the dielectric loss was 1.0% or less and the apparent dielectric constant was 2,500 or more. We also measured the temperature coefficient of capacitance, insulation resistance, boosted breakdown voltage, and equivalent series resistance, and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

3.5) Commercially available industrial strontium titanate (SrTiOa)
Ti02-MgO-3iO□ system (e.g. 30:30:
4.0 wt% sintering accelerator (40 wt ratio), semiconductor accelerator -0ff, Nb2O5, Ta2es, LazOz
, YzO3 to 1. Qwt%, grain boundary depletion layer forming agent Sro,
sBa0. Cao, 1 (Cu+yz Nb+zz)
03, Sr6. .

Bao, 3Cao, 3CCu+/z Nb+zz)Oz
2. After adding Qwt% and mixing well, it was calcined at 900°C. After wet pulverization, it is dried, granulated, molded, and fired at 1380°C in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen. After coating with bismuth oxide, it is heated at 950°C in the air.
After heat treatment, electrodes were formed and electrical properties were measured. The measurement results are shown in Table 6. Note that the sintering accelerator is, for example, T
iOz-MgO-5i(h (30:30:40wt ratio)) is a mixture of commercially available Ti(h, MgO, SiO2 powder)
:30:40 weight ratio, calcined at 1200°C, and pulverized. Furthermore, grain boundary depletion layer forming agents include commercially available 5rCO, BaCO3, CaCO3, CuO, Nb
, Os were mixed, calcined at 900°C, and pulverized.

(As is clear from Table 6 below, 5rTi03 and Ti02-
4. Sintering accelerator such as MgO-5iO□. Qwt%, semiconductor accelerator Y! 03 was 1.0 wt%, and the grain boundary depletion layer forming agent was 2.0 wt%. The material obtained by adding Qwt% and firing shows excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the fine particles of the sintered body had a uniform particle size of 2 to 3 μm depending on the composition, the dielectric loss was less than 1.0%, and the apparent dielectric constant was more than 2,000. . We also measured the temperature coefficient of capacitance, insulation resistance, boost breakdown voltage, and equal series resistance, and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 7) Titanylstrontium oxalate (SrTiO(CzO4)
)・4820) and strontium titanate (SrTiOi) obtained by thermal decomposition, sintering accelerator Ti0z-Alz03
-SiOz (ratio 20:35:45) from 0.05 to 6
．． 0 wt%, semiconductor accelerator Nb2O5 0.02-3
．． 0wt%, grain boundary depletion layer forming agent 5r (CoI2.JN
Adding 0.05 to 12.0 wt% of tlz7x)03,
After mixing well, the mixture was calcined at 900°C. After wet pulverization, it is dried, granulated, molded, sintered at 1400°C in the air, wet pulverized again, made into a paste using a resin and an organic solvent, and printed alternately with platinum paste for electrodes. 13
After hydrogen reduction at 00° C. and application of bismuth oxide, heat treatment was performed at 1150° C. in the air, electrodes were adjusted, and electrical characteristics were measured. The measurement results are shown in Table 7.

In addition, the sintering accelerator Ti (h-AI, (h-5iO□(
20:35:45w) is a commercially available TiO2
, A1. The powders of O, SiO□ were mixed in basis weight at a weight ratio of 20=35:45, calcined at 1200°C, and pulverized. Furthermore, grain boundary depletion layer forming agent 5r (Co+zi Nbz
zi) Ox is commercially available SrCO3, Coo, Nbz
Os was mixed, calcined at 900°C, and pulverized.

(Left below) As is clear from Table 7 (5rTi (h), the sintering accelerator Ti01-AIzOs-5iO2 is 0.1 to 5.0w
t%, semiconductor accelerator Nb, O5 is 0.05 to 2. Qw
t%, grain boundary depletion layer forming agent 5r (Co+z+ Nbzz+
) This material obtained by adding 0.1-10.0 wt % of Ox and firing shows extremely excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the fine particles of the sintered body have a uniform particle size of 2.0 to 4.0 μm;
Dielectric loss is 1.0% or less, apparent permittivity is 2.500
That was it. Other temperature coefficient of capacitance, insulation resistance,
We measured the boost breakdown voltage, equivalent series resistance, etc., and found satisfactory values. Note that if the sintering accelerator exceeds 5%, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 8) Commercially available industrial strontium titanate (SrTi03
) to SrO-BaO system (e.g. 75:25iit ratio)
, TiO02-Mg03iO system (e.g. 30:30:4
0wt ratio), TiOz-MnO-5iOz system (e.g. 10:50:40wt ratio), CaO-Mg0-Alz
O3-SiO2 system (e.g. 30:10:15:45wt
ratio), TiO□-AIz03-5iO□ system (e.g. 2
0:35:45wt% ratio), ZnO-Nb20s-5
iOz series (e.g. 50:45:5 wt% ratio), Z
rO2-Mn0-5iO2 system (e.g. 10:55:35
2.9wt% of the sintering accelerator selected from
Semiconductorization accelerator Y20. Q, 4 wt%, grain boundary depletion layer forming agent 5r (Co+7z Nbzz:+)03, 0.05
After adding ~12.0wt% and mixing well, 900℃
It was calcined at After wet grinding, drying, granulation, and molding,
1380℃ in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen
115 in the air after baking and coating with bismuth oxide.
Heat treatment was performed at 0° C., electrodes were formed, and electrical properties were measured. The measurement results are shown in Table 8. The sintering accelerator is, for example, TiO□-MgO-5iO□ system (30:30:4
0w ratio) is obtained by mixing commercially available Tie, MgO, 5in2 powder at a weight ratio of 30:30:40,
The product was calcined at 00°C and pulverized. Further, a grain boundary depletion layer forming agent was obtained by mixing commercially available SrCO3, Coo, and Nbz05, calcining the mixture at 900°C, and pulverizing the mixture.

(Left below) Table 8 As is clear from Table 8, 5rTi03 has TiO2-
Sintering accelerator such as MgO3iO□ is 2.9wt%, semiconductor accelerator Y! This material obtained by adding 0.4 wt % of 03 and 0.1 to 10.0 iet % of a grain boundary depletion layer forming agent and firing it exhibits extremely excellent dielectric properties and can be used as a capacitor. In other words, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well matched depending on the composition, with a diameter of 2.0 to 4.
．． At 0 μm, the dielectric loss was 1.0% or less, and the apparent dielectric constant was 2.500 or more. We also measured the temperature coefficient of capacitance, insulation resistance, boosted breakdown voltage, and equivalent series resistance, and found satisfactory values. In addition, the sintering accelerator is 5%
If it exceeds this, the sintered bodies will deform and adhere to each other, making it impractical.

(Example 9) Commercially available industrial strontium titanate (SrTiOz
) to TiOz-MgO-5iO□ system (e.g. 30:
4.011t of sintering accelerator (ratio of 30:40w)
%, semiconductor accelerator-03, Nb2O3, Taz05,
LazOz, 1.3 wt% YzO+, grain boundary depletion layer forming agent Sro, a Bao, + Cao, + (CoIz3
Nbzy3) Os, Sra, aBao, 3 Cao
, 2.0 wt% z(CCxys Nbty3)Ch
After adding and mixing thoroughly, it was calcined at 900°C. After wet pulverization, it is dried, granulated, molded, fired at 1380°C in a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen, coated with bismuth oxide, and then heat treated at 1150°C in the air to form an electrode. was formed and the electrical properties were measured. The measurement results are shown in Table 9. Note that the sintering accelerator is, for example, Ti07-M
The gO-5iO□ system (30:30:40wt ratio) uses commercially available powders of TiO□, MgO, and SiO□ in a 30:30:4 ratio.
The basis weight was mixed at a weight ratio of 0, calcined at 1200°C, and pulverized.

Furthermore, grain boundary depletion layer forming agents include commercially available 5rCOs and Ba.
It was obtained by mixing CO3, CaCO5, Coo, and Nb2O2, calcining at 900'C, and pulverizing.

However, I got a satisfactory value. In addition, when the sintering accelerator content exceeds 5%, the sintered bodies deform and adhere to each other.
Sintering accelerator such as □ is 4.0 wt%, semiconductor promotion side Y
2O3 is 1.0i1t%, grain boundary depletion layer forming agent is 2. Qi
The material obtained by adding .it% and firing exhibits excellent dielectric properties and can be used as a capacitor. That is, as a result of microscopic observation, the particle size of the fine particles of the sintered body was well matched for each composition and was 2 to 3 μm, the dielectric loss was less than 1.0%, and the apparent permittivity was more than 2,500. . We also measured the temperature coefficient of capacitance, insulation resistance, boost breakdown voltage, and equal series resistance, etc. We added sintering accelerator additives (
0.1 to 5.3 wt%), semiconducting accelerating additive (0.0
5-2.0gt%), and S'1-X-y Bay
Grain boundary depletion layer forming agent (0,
1 to 6.0 wt%), mixed and pressure molded, and then fired at 1250 to 1500°C in a reducing atmosphere containing hydrogen, and bismuth oxide (BizOi) is added to the surface of the fired product.
850-1 in an oxidizing atmosphere.
By applying heat treatment at 200°C to form electrodes,
Alternatively, although no examples were shown, Sr1-x-
F Bag Cay (Mn+zz Nb+zz)Oz
, (however, 0≦z+y≦1), a grain boundary depletion layer forming agent (0.1 to 6.0 wt%) is reacted and dissolved in solid solution, and then a sintering accelerator additive (0.1 to 5 wt%) is reacted and dissolved. .0wt%)
After adding a semiconducting accelerating additive (0.05 to 2.Qwt%), mixing and pressure molding, it is fired at 1250 to 1500°C in a reducing atmosphere containing hydrogen, and BizO is added to the surface of the fired product. : By coating a grain boundary diffusion substance containing + and performing heat treatment at 850 to 1200°C in an oxidizing atmosphere to form an electrode, or by further promoting sintering to a perovskite type oxide whose main component is 5rTiO1. Additive (0,1
~5.0wt%), semiconducting accelerating additive (0.05~2
．． 0 wt%), and Sr1-x-y Ba, Ca,
(Mn+zzNb+zz)Os, (0≦x
+y≦1) grain boundary depletion layer forming agent (0.1 to 6.0
wt%), mixed and pressure molded, and then fired in advance at 1250 to 1500°C in the air, then reduced at 800 to 1400°C in a reducing atmosphere containing hydrogen, and then applied to the surface of the sintered body. By applying a grain boundary diffusion substance containing B + zO1 and performing heat treatment at 850 to 1200°C in an oxidizing atmosphere to form electrodes, it is possible to obtain a grain boundary insulated semiconductor ceramic capacitor with long characteristics. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a grain boundary insulated semiconductor ceramic capacitor according to an embodiment of the present invention. 11... Grain boundary insulation type semiconductor ceramics, 12
... Electrode, 13 ... Lead wire.

Claims (5)

[Claims] (1) A sintering accelerator (0
．． 1-5.0 wt%), semiconductor promoter (0.05-2.
0 wt%), and at least Sr_1_−_x_−_
yBa_xCa_y(Mn_1_/_2Nb_1_/_
2) O_3, (0.1-6.0wt%) Sr_1_-_
x_−_yBa_xCa_y(Co_1_/_3Nb_
2_/_3) O_3, (0.1-10.0wt%), S
r_1_-_x_-_yBa_xCa_y(Cu_1_
/_3Nb_2_/_3)O_3, (0.1~5.0w
t%), however, a grain boundary depletion layer forming agent selected from 0≦x+y≦1 is added, mixed and pressure molded, and then 1250 to 150% in a reducing atmosphere containing hydrogen.
It is fired at 0°C, and bismuth oxide (B
A grain boundary insulated semiconductor ceramic capacitor in which electrodes are formed by applying a grain boundary diffusion substance containing i_2O_3) and performing heat treatment at 850 to 1200°C in an oxidizing atmosphere. (2) At least SrO-Ga_2O as a sintering accelerator
_3 series, TiO_2-MgO-SiO_2 series, TiO_
2-MnO-SiO_2 system, CaO-MgO-Al_2
O_3-SiO_2 system, TiO_2-Al_2O_3-
A mixture (0.1-5.0 wt%) selected from among the SiO_2 system, ZnO-Nb_2O_5-SiO_2 system, ZrO_2-MnO-SiO_2 system, at least WO_3, Nb_2O_5, Ta_2_O as semiconductor promoters.
_5, La_2O_3, Y_2O_3 or two or more oxides (0.05 to 2.0wt
%) is added to the grain boundary insulated semiconductor ceramic capacitor according to claim 1. (3) At least Sr_1_-_x_-_yB is added to the perovskite oxide mainly composed of SrTiO_3.
a_xCa_y(Mn_1_/_2Nb_1_/_2)
O_3, (0.1-6.0wt%), Sr_1_-_x
____yBa_xCa_y(Cu_1_/_3Nb_2
_/_3) O_3, (0.1-5.0wt%), Sr_
1_-_x_-_yBa_xCa_y(Co_1_/_
3Nb_2_/_3)O_3, (0.1~10.0wt
%), (however, 0≦x+y≦1), a grain boundary depletion layer forming agent selected from among the following is reacted and dissolved in solid solution,
After that, a sintering accelerator additive (0.1 to 5.0 wt%),
After adding a semiconductor-promoting additive (0.05 to 2.0 wt%), mixing and pressure molding, it is fired at 1250 to 1500°C in a reducing atmosphere containing hydrogen, and Bi_2O_3 is deposited on the surface of the fired product. A grain boundary insulated semiconductor ceramic capacitor in which an electrode is formed by applying a grain boundary diffusion substance containing the grain boundary diffusion material and heat-treating the material at 850 to 1200°C in an oxidizing atmosphere. (4) A sintering accelerator additive (0.1 to 5.0 wt%) to the perovskite oxide mainly composed of SrTiO_3,
Semiconductorization promoting additive (0.05 to 2.0 wt%) and at least Sr_1_-_x_-_yBa_xCa_y
(Mn_1_/_2Nb_1_/_2)O_3, (0.
1 to 6.0 wt%), Sr_1_-_x_-_yBa_
xCa_y(Cu_1_/_3Nb_2_/_3)O_
3, (0.1-5.0wt%), Sr_1_-_x_-
_yBa_xCa_y(Co_1_/_3Nb_2_/
_3) After adding a grain boundary depletion layer forming agent selected from O_3, (0.1 to 10.0 wt%) (however, 0≦x+y≦1), mixing and press-molding. , pre-sintered at 1250 to 1500°C in the air, then reduced at 800 to 1400°C in a reducing atmosphere containing hydrogen, and then coated with a grain boundary diffusion substance containing Bi_2O_3 on the surface of the sintered body, and then heated in an oxidizing atmosphere. A grain boundary insulated semiconductor ceramic capacitor whose electrodes are formed by heat treatment at 850 to 1200°C. (5) A sintering accelerator additive (0.1 to 5.0 wt%) to the perovskite oxide mainly composed of SrTiO_3,
Semiconductorization promoting additive (0.05 to 2.0 wt%) and at least Sr_1_-_x_-_yBa_xCa_y
(Mn_1_/_2Nb_1_/_2)O_3, (0.
1 to 6.0 wt%), Sr_1_-_x_-_yBa_
xCa_y(Cu_1_/_3Nb_2_/_3)O_
3, (0.1-5.0wt%), Sr_1_-_x_-
_yBa_xCa_y(Co_1_/_3Nb_2_/
_3) Add a grain boundary depletion layer forming agent selected from O_3, (0.1 to 10.0 wt%) (0≦x+y≦1), mix and make into a paste, and prepare for electrodes. After printing and molding alternately with paste, 125% in the atmosphere in advance.
After firing at 0 to 1,500°C, and then reducing at 800 to 1,400°C in a reducing atmosphere containing hydrogen, a grain boundary diffusion substance containing Bi_2O_3 is applied to the surface of the sintered body, and the sintered body is heated at 850 to 1,200°C in an oxidizing atmosphere. A grain boundary insulated semiconductor ceramic capacitor that is heat treated.