JPH0330308A - Separator for baking ceramic element and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain each ceramic element in which electric characteristics are stable by making each separator contain the same main ingredient as that of the ceramic element and causing the density of its separator to be lower than that of the ceramic element. CONSTITUTION:Each separator contains the same main ingredient as that of each ceramic element 16 and has density that is lower than that of the ceramic element 16. Then the mixture of a material powder containing the same main ingredient as that of the ceramic element 16 and a binder containing an organic ingredient is molded under pressure so that its pressure is lower than pressurized compacting pressure of each ceramic compact and then it is baked. Even though its baking is performed in a state where the separator 15 is sandwiched between the ceramic compacts 16, reactivity between each ceramic compact 16 and separator 15 is so low that adherence of each ceramic compact 16 to each separator is prevented and the separator does not have adverse effect on electric characteristics of each ceramic element 16. The ceramic elements 16 which have homogeneous electric characteristics are thus obtained easily with high yield.

Description

[Detailed Description of the Invention] The present invention is applied to the production of ceramic bodies for electronic components such as capacitors and varistors by firing.

The present invention relates to a separator for firing ceramic bodies that is interposed between ceramic molded bodies before firing and is used for firing, and a method for manufacturing the separator.

Ceramic bodies made from barium titanate, strontium titanate, etc. as main raw materials have been widely used in electronic components such as capacitors, varistors, and thermistors.

As for the method of firing these ceramic bodies, a large number of press-formed ceramic bodies 11 are stacked vertically in a box 12 as shown in FIG. 4, or horizontally as shown in FIG. A common method is to arrange a large number of them in the same direction and fire them in the air or in a reducing atmosphere.

However, when the molded bodies 11 are brought into close contact with each other and fired, the molded bodies 11 may react with each other, or the fired ceramic bodies may stick to each other. The disadvantage is that the yield of the element body is low.

As a way to eliminate this drawback, A1□03 and ZrO□
Alternatively, there is a method in which a powder such as ZrC is interposed between the ceramic molded bodies 11 as a bed powder and firing is performed.

However, when firing is performed with the intervening powder as described above, reactions occur at the contact areas between the powder and the molded body, which adversely affects the electrical properties of the fired ceramic body. This was a problem in obtaining a homogeneous ceramic body. This tendency is particularly noticeable during firing in a reducing atmosphere, making it difficult to obtain homogeneous semiconductor ceramics.

Therefore, as a method for preventing such adhesion between ceramic molded bodies, a powder containing strontium titanate as a main component is interposed between ceramic molded bodies containing strontium titanate as a main component. A method for manufacturing a semiconductor ceramic capacitor by firing is disclosed (Japanese Patent Publication No. 11460/1983).

In this method, it is possible to prevent the ceramic molded bodies from sticking to each other to some extent, and since the ceramic molded body and the powder have the same composition, even if the ceramic molded body and the powder come into contact with each other, the ceramic molded body and the powder cannot be fired. It is possible to suppress adverse effects on the electrical properties of the ceramic body.

However, even with the above method, the powder partially sticks to the surface of the ceramic body, and this powder cannot be easily peeled off from the ceramic body, so it is difficult to mechanically rub the ceramic body. It was necessary to match them or polish them in some way. Furthermore, if an attempt is made to remove these powders by such polishing, there is a strong possibility that the electrical properties of semiconductor ceramics will be adversely affected, and it is virtually impossible to obtain electronic components (for example, semiconductor ceramic capacitors) with good electrical properties. The problem was that it was difficult.

In view of these problems, the present invention prevents fired ceramic bodies from sticking together in the manufacturing process of ceramic bodies used in electronic parts, etc., and also produces ceramic bodies that have good and homogeneous electrical properties. It is an object of the present invention to provide a separator for firing a ceramic body that can be manufactured easily and with a high yield, and a method for manufacturing the separator.

To achieve the above object, the separator for firing ceramic bodies according to the present invention is produced by firing a ceramic molded body obtained by pressure-molding a mixture of raw material powder and a binder containing an organic component. A separate lake for firing a ceramic body which is interposed between the ceramic molded bodies when manufacturing a ceramic body by using a ceramic body, and which contains the same main component as the ceramic body and whose density is less than or equal to the density of the ceramic body. It is characterized by being

Further, when the main component is strontium titanate, the density is preferably 3.8 to 4.7 g/cm', and when the main component is barium titanate, the density is 4.
．． 3 to 5.3 g/cm" is preferable.

Furthermore, the perovskite crystal structure (-grain RMO, +
+, A/B (however, A is metal ion R
The number of atoms of the metal ion M (B is the number of atoms of the metal ion M) is 1.00<A/B≦1.02.

Furthermore, in the method for producing a separator for firing a ceramic body according to the present invention, a mixture of a raw material powder containing the same main component as that of the ceramic body and a binder containing an organic component is heated under a pressure forming pressure of a ceramic molded body. It is characterized in that it is pressure-molded at a low temperature and then fired.

Further, the amount of the binder containing the organic component may be greater than the amount of the binder containing the organic component contained in the ceramic molded body for firing.

According to the above structure, the separator for firing the ceramic body (hereinafter simply referred to as "separator") is made of the same main component as the ceramic body, and the density of the separator is smaller than the density of the fired ceramic body. Even if the separator is fired with the separator interposed between the ceramic molded bodies, the reactivity between the ceramic molded body and the separator is low, and it is possible to prevent the ceramic molded body and the separator from sticking together.

That is, unlike the case where a powdered bedding material different from the components of the ceramic body is interposed between the ceramic molded bodies, the reactivity between the ceramic molded body and the separator is low;
The separator does not adversely affect the electrical properties of the ceramic body, and since no powder is used, powder does not stick to the ceramic body as in the past.

That is, when manufacturing a ceramic body, as shown in FIG. The firing atmosphere is made constant, and the electrical properties of the fired ceramic body are made uniform.

Furthermore, as shown in FIG. 2, a ceramic body 19 made of the same main component as the ceramic body and fired
When the separator 18 having dimensions different from those of the ceramic body 19 is interposed between the unsintered ceramic molded bodies, the separator 18 and the ceramic body 19 can be easily separated.

That is, for example, when firing disc-shaped ceramic molded bodies, if a separator with the same dimensions as these molded bodies is interposed, the molded body and the separator will have the same dimensions at the "packing" stage before firing. , can be stacked and fired. Then, when the molded body is fired to become a ceramic body, the ceramic body shrinks by about 20% from the ceramic molded body. In other words, as shown in Figure 2,
The fired ceramic body 19 has an overall smaller size than the separator 18 which does not shrink. Therefore, in a process after firing, for example, an electrode printing process, the separator 18 is removed (as shown in FIG. , the separator 18 can be easily removed.

Further, as described above, the separator has the same main components as the ceramic body, but if the density is too high, it will have an adverse effect on the electrical properties, while if the density is too low, the strength will be weak (i.e. There is an optimum range of separator density.

In the present invention, in the case of a separator whose main component is 5rTiOa, the density is set in the above-mentioned optimum range of 3.8 to 4.
7g/cm", and for separators whose main component is BaTi0m, the density is set at 4.3 to 5.3g.
/cm'', it is possible to prevent the deterioration of the electrical properties of the ceramic body without damaging the separator.

Furthermore, the separator having a desired density can be manufactured by adjusting the molding pressure when molding the raw material for separator and the content of the binder containing organic components contained in the raw material.

That is, by setting the molding pressure in the molding process in the separator manufacturing process lower than the molding pressure during manufacturing the ceramic body, it is possible to manufacture a separator having a density lower than that of the ceramic body. In addition, by setting the content of the binder containing an organic component to be higher than the content of the binder containing an organic component contained in the ceramic molded body for producing the ceramic body, the content of the binder containing an organic component may be set to be higher than the density of the ceramic body. Separators with low density can be produced.

In addition, when manufacturing a ceramic body having a perovskite crystal structure represented by -M formula RMO,
A/B (where A is the number of atoms of the metal ion R: 1, B is the number of atoms of the metal ion M) is 1.00<A/B≦1,02
By interposing a separator between ceramic molded bodies and firing, a ceramic body with excellent electrical properties can be obtained. In other words, in a separator having the above atomic ratio (A/B), its crystal structure is stabilized, and the fired ceramic bodies do not stick to each other.
A ceramic body with good electrical properties can be obtained.

Examples of the present invention will be described in detail below, but it goes without saying that the present invention is not limited to these examples.

[Example 1] Strontium titanate (SrTiOa) is mixed with niobium oxide (NbaOa) at O1 mol% to 0.4 mol%, and 1lrl oxide (CuO) as a sintering aid at o, i mol%.
It was added in an amount of 0.2 mol % and thoroughly mixed in a ball mill to produce a powdered ceramic raw material.

Next, 2.5 wt% polyvinyl alcohol (PVA) was added to this ceramic raw material as a binder containing organic components.
) was added and thoroughly mixed again in the ball mill. After this, the ceramic raw material powder is granulated through a 60 mesh sieve, and then pressure molded at a molding pressure of 2.0 (ton/cm21) to form a 10mmφX1.Eun
A disc-shaped ceramic molded body for electronic components (first ceramic molded body) of mt was produced.

On the other hand, the ceramic raw material granulated by passing through a 60-mesh sieve in the same manner as described above was
Pressure molding with a molding pressure within the range of n/cm"),
A disc-shaped separator ceramic molded body (second ceramic molded body) having a diameter of 12 mm and a diameter of 1.5 mm was prepared.

Next, the first ceramic molded body and the second ceramic molded body were fired in the atmosphere at a temperature of 1000° C. for 2 hours to remove the binder (PVA).

After that, the second ceramic molded body was made into B2, N2
Under a reducing (mixed) atmosphere, at a temperature of 1,440 to 1,530°C,
It was fired under the conditions of 2 to 6 hours for a firing time of 10 mmφ x 1.
A disc-shaped separator with a thickness of 5 mm was produced.

Next, the first ceramic molded body and the separator are placed in the box 17 with the separator interposed between the 210 stacked first ceramic molded bodies (see FIG. 1 LH!, N! Under reducing (mixed) atmosphere, temperature 1440
The first ceramic molded body was fired under the conditions of ~1530°C and a firing time of 2 to 6 hours to obtain a ceramic body.

After this, a diffusion substance consisting of B12D3 and CuO was applied to one side of the ceramic body, and the
Heat treatment was performed at ~1300°C for 1 to 2 hours, and silver electrodes were further provided on both sides of the ceramic body.

Table 1 shows the results when 100 pieces of the first ceramic molded bodies were fired in a reducing atmosphere by changing the packaging method. Here, the dielectric constant ε and the dielectric loss tan δ (%) were determined from values measured under an alternating current voltage of 1 kHz IV. In addition, the insulation resistivity p is the DC voltage 2
This value was determined from the current value after applying 5V for 1 minute.

(Hereinafter, blank space) In Table 1, no mark indicates the present invention, and * mark indicates not covered by the present invention. In addition, among the manufacturing conditions, "none" indicates the case where only the first ceramic molded body is laminated as it is and fired, and "r5rTiOs powder" means that 5rTiOa powder is interposed between the first ceramic molded bodies as a bed powder. "Separator" indicates a case where a separator is interposed in the first ceramic molded body. Also, the standard deviation O
Dispersion can be determined from the value of n-+.

As is clear from Table 1, when the first ceramic molded bodies are piled up as they are and fired, the fired ceramic bodies do not stick together, and the yield rate is low at 25%. When 5rTiOa powder is used as a bedding powder, the yield rate of baked ceramic bodies is quite good at 90%, but the standard deviation is 0.
It can be seen that the value of n-1 is large, and there is large variation in the electrical characteristics.

Furthermore, when attempting to form a separator with a molding pressure of 0.005 (ton/cm21), the separator itself was damaged and could not be used as an inclusion. /c+++”i or higher, the quality of the fired ceramic body is 100%, but the density of the separator is 4.74 ig/cm3) or higher, and the ceramic body is not good. The density approaches that of the body, causing variations in electrical properties.

On the other hand, when the molding pressure is 0.01 to 0.8 no./cm
”), the molding pressure when molding the first ceramic molded body is lower than 2.0 (t, on/cm”l),
Separator density is 3.80 to 4.70 fg/cm3
), which is sufficiently low compared to the density of the ceramic body, so the reactivity between the first ceramic molded body and the separator is extremely low (to obtain a ceramic body with good electrical properties with little variation). be able to.

Moreover, by interposing the separator, the ceramic bodies do not stick to each other after firing, and no damage or cracks occur in the ceramic bodies, resulting in a yield rate of 10%.
It was 0%.

In this Example 1, the separator was produced by adjusting the molding pressure, but instead of changing the molding pressure, the amount of binder containing an organic component added to the ceramic raw material was adjusted to obtain the desired amount. Alternatively, a separator having a desired low density can be obtained by adjusting both the molding pressure and the amount of binder containing an organic component. In the following Example 2, a case will be described in which a separator is manufactured by adjusting the amount of a binder containing barium titanate (BaTiOa) as a main component and an organic component.

[Example 2] Lanthanum oxide (t) was added to barium titanate (BaTiOa).
0.1 mol % to 0.4 mol % of aiozl, and 0.1 mol % to 0.4 mol % of silicon oxide C51O□) as a sintering aid. O1 mol% ~
It was added in an amount of 0.2 mol % and thoroughly mixed in a ball mill to create a powdered ceramic raw material powder.

Next, a binder containing 2.5 wt % of organic components was added to the ceramic raw material powder, and then thoroughly mixed in the ball mill again. Here, examples of binders containing organic components include polyvinyl alcohol (PVA), polyvinyl butyral (PVBI), polyethylene glycol (PEG), and polyvinyl butyral (PVBI).
1. Vinyl acetate resin, methylcellulose, nitrocellulose, wax emulsion, or a mixture thereof was used.

Next, this was granulated through a 60-mesh sieve, and then pressure-molded at a molding pressure of 2.0 (ton/cm") to produce a first disc-shaped ceramic molded body of 10 mrnφ x 1.5 mm'. did.

On the other hand, 4.
After adding a binder containing 0 to 40.0 wt% of organic components, this was thoroughly mixed in a ball mill. After that, this was granulated through a 60 mesh 1 sieve, and the molding pressure was 2. 12++u at a pressure of O(ton/cm"l)
A second disc-shaped ceramic molded body having a diameter of sφX1.5 mm' was produced. Here, as the binder containing an organic component, polyvinyl alcohol (PVAI), polyvinyl butyral (PVB), etc. are used, as in the first ceramic molded body.
, polyethylene glycol (PEG), vinyl acetate resin, methylcellulose, nitrocellulose, wax emulsion, or a mixture thereof.

Next, the first ceramic molded body and the second ceramic molded body were fired in the atmosphere at a temperature of 1000° C. for 2 hours to remove the binder.

After that, the second ceramic molded body was made of H2, Na
Under a reducing (mixed) atmosphere, at a temperature of 1350 to 1450°C,
Fired under the conditions of 2 to 6 hours of firing time, 10mmφX 1
．． A 5 mm' disk-shaped separator was produced.

Next, the first ceramic molded body and the separator are placed in a box 17 with the separator interposed between the ten stacked first ceramic molded bodies (see FIG. 1!, Ha, The first ceramic molded body was fired under conditions of a reducing (mixing) atmosphere of Na, a temperature of 1350 to 1450°C, and a firing time of 2 to 6 hours to obtain a ceramic body.

After this, Bi2O5 and Pb30 are applied to one side of the ceramic body. Apply a diffusive substance consisting of 1 in the atmosphere.
Heat treatment was performed at 000 to 1300°C for 1 to 2 hours, and silver electrodes were further provided on both sides of the ceramic body.

Table 2 shows the results when 100 pieces of the first ceramic molded bodies were fired in a reducing atmosphere by changing the packaging method. Here, the dielectric constant ε and the dielectric loss tan δ (%) were determined from values measured under an AC voltage of 1 kHz and IV. Insulation resistivity p is DC voltage 25V
It was determined from the current value after applying for 1 minute.

Moreover, in Table 2, no mark indicates the present invention, and * mark indicates not covered by the present invention. In addition, among the manufacturing conditions, "none" indicates the case where only the first ceramic molded body is laminated as it is and fired, and "r BaTi0a powder" means that the BaTi island powder is interposed between the first ceramic molded bodies as a bed powder. "Separator 1 Nota" indicates a case in which a separator is interposed between the first ceramic molded bodies.

(Hereinafter, blank space) As is clear from Table 2, when the first ceramic molded bodies are laminated as they are and fired, the fired ceramic bodies stick together, and the yield rate after firing is 23%. Yield is low.

In addition, when BaTi0a powder is used as a bedding powder, the yield rate of baked ceramic bodies is quite good at 88%, but the value of standard deviation on-t is large and the variation in electrical properties is large. It shows. Furthermore, when attempting to produce a separator with a binder addition amount of 40.0 (wt%), the separator itself was damaged and could not be used as an inclusion. On the other hand, when using a separator made with the amount of binder added at 4.8 (wt, %) or less, the yield rate of the ceramic body was 100%, but the density of the separator was 5.34 (
g/am3) or more, approaching the density of the ceramic element body, resulting in variations in electrical properties.

On the other hand, the amount of binder added was 5.4 to 25.8 (w
t%), the density of the separator is 4.30 to 5.
．． 30 (wt%), and the density of the separator is sufficiently small compared to the density of the ceramic body.2 The reactivity between the first ceramic molded body and the separator is extremely low, so that good electrical properties with little variation can be achieved. We were able to obtain a ceramic body with specific properties.

Moreover, since the separator was interposed, the ceramic bodies did not stick to each other after firing (no damage or cracks occurred in the ceramic bodies), and the yield rate was 100%.

[Example 3] In Example 3, a separator suitable for forming a ceramic body having a herovskite crystal structure, a method for manufacturing the separator, and electrical characteristics of the fired ceramic body will be described in detail.

First, as shown in Table 5, 0.995 to 0.997 (
mol) of 5rCOs and 0.996 fmol)
of Tl0I, and 0.002 (mol) of Nb*oa,
A raw material powder (first composition) consisting of 0.002 (rlIol) of CuO as a sintering aid was thoroughly mixed, and 1
After calcining at a temperature of 100 to 1250°C, it was pulverized.

This first composition is then coated with polyvinyl alcohol (P
After adding a binder containing organic matter such as VA), it is granulated through a 60-mesh sieve, and then the molding pressure is 2.0.
(ton/cm") and 10mmφX1.
A first ceramic molded body in the shape of a disc with a diameter of 5 mm was produced. In this example, for example, PVA was used as the binder containing an organic component, but it is not particularly limited.Also, the amount added is not particularly limited, but it is 1 to 5 (wt%). ) is desirable, and more preferably 2.25 to 2.5 fvt%).

Thereafter, the first ceramic molded body was fired in the atmosphere at a temperature of 1000° C. for 2 hours to remove the binder. Next, 5rCOa, cacOi, Tio
After thoroughly mixing the raw material powder (second composition) containing NbJa, NbJa, Ta205, and CuO as a sintering aid, the powder was calcined at a temperature of 1100 to 1250°C and pulverized.

Table 3 shows the compounding conditions of these second compositions in moles.

Table 3 In Table 3, A/B represents the perovskite crystal structure (general formula R
In M Osl, it shows the atomic ratio between the number of atoms A of metal ions R such as Sr, Ca, etc. and the number B of atoms of metal ions M such as Ti, Nb, Ta, etc. (see the "action" section)
.

After adding a binder containing an organic substance such as polyvinyl alcohol (PVA) to the second composition,
Granulate through a mesh sieve, then press 2. O
(ton/am2), 12mmφX1.5
A second disc-shaped ceramic molded body having a diameter of mmt was produced.

Next, the second ceramic molded body was heated to 1000°C in the atmosphere.
After removing the binder by baking at a temperature of 2 hours,
Under a reducing (mixed) atmosphere of N2, N2, temperature! 440
Baked under the conditions of ~1530°C and a firing time of 2 to 6 hours, 1
A disc-shaped separator with a diameter of 0 mm and a diameter of 1.5 mm was prepared.

After that, with the separator interposed between the first ceramic molded bodies stacked together, the first
put the ceramic molded body and the separator into a box,
N2. Under a reducing (mixed) atmosphere of N, at a temperature of 1440~
The first ceramic molded body was fired under the conditions of 1530°C and a firing time of 2 to 6 hours to produce a ceramic body.

After that, a diffusion substance consisting of B1□0° and CuO was applied to one side of the ceramic body, and the
Heat treatment was performed at 0 to 1300'C for 1 to 2 hours, and silver electrodes were further provided on both sides of the ceramic body.

Tables 4 and 5 show that the packing method was changed and the first
The results are shown when 100 ceramic molded bodies were fired in a reducing atmosphere. Here, the dielectric constant ε and the dielectric loss tan δ (%) were determined from values measured under an alternating current voltage of 1 kHz and 1 V. Further, the insulation resistivity ρ was determined from the current value after applying a DC voltage of 25 V for 1 minute.

(Hereinafter, blank space) In Table 4, no mark indicates the present invention, and * mark indicates not covered by the present invention. In addition, "None" indicates the case where only the first ceramic molded body is laminated and fired as it is, and rSr
Ti(h) indicates the case where 5rTiO powder is interposed between the first ceramic molded bodies as a bed powder, and "separator" refers to No. 3 separator in Table 3 above.
The case is shown in which a ceramic molded body is interposed.

As is clear from Table 4, when the first ceramic molded bodies are laminated as they are and fired, the fired ceramic bodies stick together, resulting in a low yield rate of 25% after firing. In addition, when 5rTi03 was used as a bedding powder, the yield rate was quite good at 90%, but the value of the standard deviation 0n-1 was large, indicating that there was a large dispersion in the electrical properties.

On the other hand, when ceramic bodies were produced using separators No. 3, the ceramic bodies did not stick to each other after firing, did not cause any damage or cracks, and the yield rate was 100%. .

Moreover, it was possible to obtain a ceramic body having very low reactivity between the first ceramic molded body and the separator (and good electrical properties with little variation).

Furthermore, as is clear from Table 5, when the first ceramic molded body is fired in a reducing atmosphere, the ratio A/B of the number of atoms in the perovskite crystal structure is 1.00<A
By interposing a separator within the range of /B≦1.02 between the first ceramic molded bodies and firing, the fired ceramic body exhibits good electrical properties, and the resulting semiconductor ceramic capacitor has good electrical properties. We were able to significantly improve the characteristics.

[Example 4] In this example, another example of a separator having a perovskite crystal structure will be described in detail.

First, as shown in Table 8, 0991 to 0.993 (
BaC0a of mail and 1.000 (mol)
A raw material powder (first composition) consisting of Ti0z of
After calcining at a temperature of 100 to 1300°C, it was pulverized.

This first composition is then coated with polyvinyl alcohol (P
After adding a binder containing an organic component such as VA), 6
Granulated through a 0 mesh sieve, compacting pressure 2.0 [t
on/cm") to form a 10mmφX1.
A first ceramic molded body in the shape of a disc with a diameter of 5 mm was produced.

Thereafter, the first ceramic molded body was fired in the atmosphere at a temperature of 1000° C. for 2 hours to remove the binder. In this example, as in Example 3, for example, PVA was used as the binder, but the type and amount added are not particularly limited, but it is preferably in the range of 1 to 51 wt%. , more preferably in the range of 2.25 to 2.5 (wt%).

Next, Bacos, 5rCOs, Ti0z, Y
After thoroughly mixing the raw material powder (second composition) containing iOa, Taxes, and SiO□ as a sintering aid,
It was calcined at a temperature of 1100 to 1300°C and pulverized. 6th
The table shows the number of moles under the compounding conditions of these second compositions.

Table 6 In Table 6, the physical meanings of A/B are the same as in Example 3 and are omitted.

However, this second composition contains polyvinyl alcohol (
After adding a binder containing organic components such as PVA),
It was granulated through a 60 mesh sieve, and the molding pressure was 2.0 (
A second disc-shaped ceramic molded body measuring 12 mm $ x 1.5 mm' was produced at ton/cm"l.

Next, the second ceramic molded body was heated to 1000°C in the atmosphere.
After removing the binder by baking at a temperature of 2 hours,
Hz, Nt reducing (mixed) atmosphere, temperature 1350~
Sintered at 1450°C for 2 to 6 hours.
A disc-shaped separator with mmφ×1.5 mm′ was produced.

After that, the first ceramic molded body and the separator are placed in a box with the separator interposed between the 10-layered first ceramic molded body, and N2
, under a reducing (mixed) atmosphere of N2, at a temperature of 1440-153
The first ceramic molded body was fired under the conditions of 0° C. and a firing time of 2 to 6 hours to produce a ceramic body.

Next, BiJi and CuO were deposited on one side of the ceramic body.
Apply a diffusing substance consisting of 1000 to 13
A heat treatment was performed at 00° C. for 1 to 2 hours, and silver electrodes were further provided on both sides of the ceramic body.

Tables 7 and 8 show that the packing method was changed and the first
The results are shown when 100 ceramic molded bodies were fired in a reducing atmosphere. Here, the dielectric constant ε,
The dielectric loss tan δ (%) was determined from the value measured under an alternating current voltage of L kHz and 1 V. Further, the insulation resistivity ρ was determined from the current value after applying a DC voltage of 2 SV for 1 minute.

In Table 7, no mark indicates the present invention, and * mark indicates not covered by the present invention. In addition, "None" indicates the case where only the first ceramic molded body is laminated as it is and fired, and rBa
"Tios powder" indicates the case where BaTi0a powder is interposed between the first ceramic molded bodies, and "separator" indicates the case where the separator No. 3 in Table 6 is interposed between the first ceramic molded bodies. It shows.

As is clear from Table 7, when the first ceramic molded bodies are laminated and fired, the fired ceramic bodies stick together, resulting in a non-defective product rate of 23% after firing.
and the yield is low. Furthermore, when BaTi0+ powder is used as a bedding powder, the yield rate of ceramic bodies is quite good at 88%, but the value of the standard deviation On-+ is large, indicating that there is large variation in electrical properties. .

On the other hand, when ceramic bodies were formed using separators No. 3, the ceramic bodies did not stick to each other after firing, did not cause any damage or cracks, and the yield rate was 100%. Ta.

Moreover, the reactivity between the first ceramic molded body and the separator was extremely low (and a ceramic body having good electrical properties with little variation could be obtained).

Furthermore, as is clear from Table 8, when the first ceramic molded body is fired in a reducing atmosphere, the ratio A/B of the number of atoms in the perovskite crystal structure is 1.00<A/
By interposing a separator within the range of B''51.02 between the first ceramic molded bodies and firing, the fired ceramic body exhibits good electrical properties, and the electrical properties of the resulting semiconductor ceramic capacitor are improved. could be significantly improved.

As described in detail above, the separator according to the present invention is made of the same main component as the ceramic molded body, and its density is lower than the density of the ceramic body. When fired with the ceramic molded body interposed between the molded bodies, the reactivity between the ceramic molded body and the separator is low. In addition, since the ceramic body is fired without any powder intervening between the ceramic molded bodies,
The fired ceramic body has good electrical properties.

In addition, for a separator whose main component is 5rTiO1, its density is set to 3.8 to 4.7 g/am', and for a separator whose main component is BaTiOs,
By setting the density to 4.3 to 5.3 g/am3, a ceramic body with good electrical properties can be obtained.

In addition, by manufacturing the separator by setting the molding pressure in the molding process lower than the molding pressure when forming the ceramic body, it is possible to easily and easily make the density of the separator smaller than the density of the ceramic body. I can do it.

Similarly, by setting the content of the binder containing organic components contained in the ceramic raw material to be higher than the content of the binder containing organic components contained in the molded body for forming the ceramic body, it is possible to easily and easily The density of the separator can be made smaller than the density of the ceramic body.

In this way, the separator can be manufactured simply and easily, and the manufacturing cost is also low.

In addition, it generally has a perovskite crystal structure (general formula RM
O3), A/B (where A is the number of atoms of the metal ion R and B is the number of atoms of the metal ion M) is 1.00<A/B≦1. By using a separator of 0.02, a ceramic body with improved electrical properties can be obtained.

As described above, by interposing the separator according to the present invention between ceramic molded bodies and firing, it is possible to easily obtain a ceramic element body with stable electrical properties, and as a result, a semiconductor ceramic capacitor with significantly improved electrical properties can be obtained. It has the remarkable effect that it is possible to easily manufacture electronic components such as the following, and that the yield thereof can be dramatically improved.

4. Brief explanation of the drawings Fig. 1 is a schematic cross-sectional view showing the ceramic molded bodies and the separately arranged state in the box in the method according to the present invention, and Fig. 2 shows the dimensions of the separator compared to the dimensions of the ceramic body. Schematic sectional view showing the method in which the size is increased, FIG. 3 f
a) is a plan view showing an example of a jig used for sorting ceramic bodies, FIG. 3+b+ is a sectional view thereof, and FIGS. 4 and 5 show a conventional method of firing a compact. It is a schematic sectional view.

Fig. 1 15. 18... Separator, 16... Ceramic molded body, 19... Ceramic element body.

Patent applicant: Sumitomo Metal Industries, Ltd. Agent: Patent attorney Ryuji Iuchi Figure 2

Claims (6)

[Claims] (1) For firing a ceramic body to be interposed between ceramic bodies when forming a ceramic body by firing a ceramic body obtained by press-molding a mixture of raw material powder and a binder containing an organic component. 1. A separator for firing a ceramic body, the separator comprising the same main component as the ceramic body and having a density lower than the density of the ceramic body. (2) The separator for firing a ceramic body according to claim (1), wherein when the main component is strontium titanate, its density is 3.8 to 4.7 g/cm^3. (3) The separator for firing ceramic bodies according to claim (1), wherein when the main component is barium titanate, its density is 4.3 to 5.3 g/cm^3. (4) Perovskite crystal structure (general formula RMO_3)
In this case, A/B (where A is the number of atoms of metal ion R and B is the number of atoms of metal ion M) is 1.00<A/
The separator for firing a ceramic body according to claim 1, wherein B≦1.02. (5) A mixture of a raw material powder containing the same main components as the ceramic body and a binder containing an organic component is pressure-molded at a pressure lower than that of the ceramic molded body, and then fired. A method for producing a separator for firing a ceramic body. (6) Production of a separator for firing a ceramic body according to claim (5), wherein the amount of the binder containing an organic component is greater than the amount of the binder containing an organic component contained in the ceramic molded body. Method.