JPH0614501B2 - Porcelain capacitor and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a single-layer or multilayer-structured ceramic capacitor in which a dielectric ceramic layer is sandwiched by at least two or more internal electrodes, and a method for manufacturing the same. .

[Prior Art] A laminated ceramic capacitor is manufactured by printing a conductive paste in a desired pattern on an unsintered porcelain sheet (green sheet) made of dielectric ceramic raw material powder, stacking a plurality of the pastes and press-bonding them in an oxidizing atmosphere. Is manufactured by firing at 1300 ° C to 1600 ° C.

By this firing, the green ceramic sheet becomes a dielectric ceramic layer, and the conductive paste becomes an internal electrode.

By the way, conventionally, as the conductive paste, a paste containing a noble metal such as platinum or palladium as a main component has been used.

This is because if a conductive paste containing a noble metal such as platinum or palladium as a main component is used, the conductive paste is not oxidized even if it is fired at a high temperature of 1300 ° C. to 1600 ° C. in an oxidizing atmosphere. This is because the desired internal electrode can be modified.

However, since precious metals such as platinum and palladium are expensive, the laminated ceramic capacitor inevitably has a problem of high cost.

As a solution to this problem, Japanese Patent Publication No. 60-20851 relating to the applicant of the present invention describes {(Ba _X C
a _y Sr _z O} _K (Ti _n Zr _1-n ) O _{2 as} a basic component and Li ₂ O, SiO ₂ and MO (where MO is BaO, CaO and Sr).
Disclosed is a dielectric ceramic composition containing an additive component composed of one or more oxides selected from O).

In addition, in Japanese Patent Laid-Open No. 61-147404, {(Ba
_1-xy Ca _x Sr _y ) O} _K (Ti _1-z Zr _z ) O ₂ and B
A dielectric ceramic composition containing ₂ O ₃ , SiO _2, and an additive component composed of Li ₂ O is disclosed.

In addition, in Japanese Patent Laid-Open No. 61-147405, {(Ba
_1-xy Ca _x Sr _y ) O} _K (Ti _1-z Zr _z ) O ₂ and B
A dielectric ceramic composition containing ₂ O ₃ and an additive component made of SiO ₂ is disclosed.

In addition, in Japanese Patent Laid-Open No. 61-147406, {(Ba
_1-xy Ca _x Sr _y ) O} _K (Ti _1-z Zr _z ) O ₂ and B
₂ O ₃ , SiO _2, and MO (where MO is BaO, CaO
And an additive component composed of one or more kinds of oxides selected from SrO) are disclosed.

The dielectric ceramic compositions disclosed in these publications can be obtained by firing at a relatively low temperature of 1200 ° C. or lower in a reducing atmosphere, but their relative permittivity ε is 5000 or higher and resistance is The rate ρ is 1 × 10 ⁶ MΩ · cm or more.

[Problems to be Solved by the Invention] By the way, in recent years, the progress toward higher density of electronic circuits is remarkable, and there is a strong demand for miniaturization of laminated ceramic capacitors.

Therefore, the relative permittivity ε of the dielectric ceramic composition that constitutes the dielectric layer of the laminated ceramic capacitor, the dielectric ceramic composition of the dielectric ceramic composition disclosed in the above publications without deteriorating other electrical characteristics. It has been desired to further increase the relative permittivity ε.

Therefore, an object of the present invention is to provide 1 in a non-oxidizing atmosphere.
Despite being obtained by firing at a temperature of 200 ° C. or less, the dielectric ceramic composition constituting the dielectric layer has a relative permittivity ε of 7,000 or more and a dielectric loss tan δ of 2.
It is an object of the present invention to provide a porcelain capacitor having an electrical characteristic of 5% or less and a resistivity ρ of 1 × 10 ⁶ MΩ · cm or more, which is more excellent than conventional ones, and a manufacturing method thereof.

[Means for Solving the Problems] A porcelain capacitor according to the present invention includes a dielectric porcelain layer made of a dielectric porcelain composition and at least two internal electrodes sandwiching the dielectric porcelain layer. In a porcelain capacitor, the dielectric porcelain composition is formed by firing a mixture of 100.0 parts by weight of a basic component and 0.2 to 5.0 parts by weight of an additive component, and the basic component is (Ba _1-WX Ca _W Sr _X ) 0} _K (Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
one or more elements selected from b, Tb, Tm and Lu, w, x, y, z, k are: 0 ≦ w ≦ 0.27 0 <x ≦ 0.37 0 <y <0 .26 0.05 ≦ 0.6x + y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04, and the additive components are B ₂ O ₃ and SiO ₂ . Li ₂ consists O, the composition range of the _B 2 _{O 3} and said SiO ₂ and said Li ₂ O is, in a triangular diagram showing these compositions in mol%, the _B 2 _{O 3} is 1 mol%, the SiO ₂ is 50 mol%,
A first point A showing a composition of Li ₂ O of 49 mol%, B ₂ O ₃ of 50 mol%, SiO ₂ of 1 mol%,
A second point B showing a composition of 49 mol% of Li ₂ O, 80 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A third point C showing a composition of Li ₂ O of 19 mol%, a third point C showing a composition of B ₂ O ₃ of 89 mol%, a content of SiO ₂ of 10 mol%, and a composition of Li ₂ O of 1 mol%. Point D of 4
And a fifth point E indicating a composition in which B ₂ O ₃ is 19 mol%, SiO ₂ is 80 mol%, and Li ₂ O is 1 mol%.
And B ₂ O ₃ is 1 mol%, SiO ₂ is 80 mol%,
The Li ₂ O is in a region surrounded by six straight lines connecting in this order with the sixth point F indicating the composition of 19 mol%.

Here, the ratio of the number of Ca atoms in the composition formula of the basic component, that is, the value of w is 0 ≦ w ≦ 0.27,
When the value of 0 ≦ w ≦ 0.27, a sintered body having desired electrical characteristics, flat temperature characteristics, and high resistivity ρ can be obtained. This is because if it exceeds, the firing temperature becomes higher than 1250 ° C. and the relative dielectric constant ε _s becomes less than 7,000.

Since Ca is an element used to flatten the temperature characteristics of the porcelain capacitor and to improve the resistivity ρ as described above, even if it is not contained, that is, the value of w is set to zero. Also, a sintered body having desired electrical characteristics can be obtained.

In addition, the value of the relational expression 0.6x + y is 0.05 ≦ 0.6x +
y ≦ 0.26 means that when the value of the relational expression 0.6x + y is in this range, a sintered body having desired electrical characteristics can be obtained, but the value of the relational expression 0.6x + y is 0.
If it is less than 05 or exceeds 0.26,
This is because the relative permittivity ε _s is less than 7,000 in both cases.

However, even if the value of the relational expression 0.6x + y is 0.26 or less, if the value of x exceeds 0.37, the relative permittivity ε _s becomes 70.
It is less than 00. Therefore, the upper limit of the relational expression 0.6x + y is 0.26, but at the same time, the upper limit of x must be 0.37.

It should be noted that Sr and Zr, whose ratios are shown by x and y, are elements having an action of shifting the Curie point to the low temperature side and increasing the relative dielectric constant at room temperature, and 0 <x ≦ 0.3.
7 and 0 <y <0.26, and 0.
It can be used in a range satisfying 05 ≦ 0.6x + y ≦ 0.26.

The ratio of the number of R atoms in the composition formula of the basic component,
That is, the value of z is set to 0.002 ≦ z ≦ 0.04, that is, when the value of z is 0.002 ≦ z ≦ 0.04, a sintered body having desired electrical characteristics can be obtained. I can, but
When it becomes less than 0.002, dielectric loss tan δ
And the resistivity ρ is less than 1 × 10 ³ MΩ · cm, and when it exceeds 0.04, a dense sintered body can be obtained even if the firing temperature is 1250 ° C. Because you can't.

In addition, Sc, Y, Gd, Dy, Ho, Er, Y of R component
b, Tb, Tm and Lu work in much the same way, using one or more selected from them to obtain similar results.

The ratio of {(Ba _1-WX Ca _W Sr _X ) 0} in the composition formula of the basic component, that is, the value of k is 1.00 ≦ k ≦ 1.04, is because the value of k is 1.00. When ≦ k ≦ 1.04, a sintered body having desired electrical characteristics can be obtained, but when it is less than 1.00, the resistivity ρ is 1 ×.
This is because it is significantly low at less than 10 ⁶ MΩ · cm, and when it exceeds 1.04, a dense sintered body cannot be obtained.

Of the R components in the composition formula of the basic component, T
Although b, Tm and Lu are not shown in Table 1 described later, they also have the same action and effect as other R components.

Further, a small amount of a mineralizing agent such as MnO ₂ (preferably 0.05 to 0.1% by weight) is added to the basic components within a range that does not impair the object of the present invention to improve sinterability. May be.
Moreover, you may add another substance as needed.

In addition, as a starting material for obtaining the basic component, an oxide other than those shown in the examples may be used, or a hydroxide or another compound may be used.

Next, the addition amount of the additive component is set to 0.2 to 5.0 parts by weight with respect to 100 parts by weight of the basic component. The reason is that when the addition amount of the additive component is within this range, 1180 to 1190 ° C. Although a sintered body having the desired electrical characteristics can be obtained by firing, if the amount is less than 0.2 parts by weight, the firing temperature will be 125.
A dense sintered body cannot be obtained even at 0 ° C,
Further, if it exceeds 5.0 parts by weight, the relative permittivity ε _s is 700.
This is because it becomes less than 0.

In the triangular diagram showing the composition of the additive component in terms of the composition of B ₂ O ₃ , SiO ₂ and Li ₂ O in mol%, points A to F described above
Within the range surrounded by the six straight lines connecting in this order, if the composition of the additive component is within this range, a sintered body having desired electrical characteristics can be obtained. This is because if the composition of the additive component is out of this range, a dense sintered body cannot be obtained.

Next, the method for manufacturing a porcelain capacitor according to the present invention comprises a step of preparing a mixture of unsintered porcelain powder consisting of the basic component and the additive component, and a green porcelain sheet formed of the mixture. And a step of forming a laminate in which the green ceramic sheet is sandwiched by at least two or more conductive paste films, a step of heat-treating the laminate in a non-oxidizing atmosphere, and a step of receiving the heat treatment. And a step of heat-treating the laminated body in an oxidizing atmosphere.

Here, the non-oxidizing atmosphere may be not only a reducing atmosphere such as H ₂ or CO but also a neutral atmosphere such as N ₂ or Ar.

Further, the temperature of the heat treatment in the non-oxidizing atmosphere can be variously changed in consideration of the electrode material. When nickel is used as the internal electrode, the heat treatment can be performed in the range of 1050 ° C to 1200 ° C with almost no agglomeration of nickel particles.

The temperature of the heat treatment in the oxidizing atmosphere may be lower than the sintering temperature, and is preferably in the range of 500 to 1000 ° C. It is necessary to change the temperature in consideration of the oxidation of the electrode material (such as nickel) and the oxidation of the dielectric ceramic layer. Although the temperature of this heat treatment was set to 600 ° C. in the examples described later, the temperature is not limited to this temperature.

The present invention is of course applicable to general single-layer porcelain capacitors other than laminated porcelain capacitors.

[Example] First, the sample No. The case of 1 will be described.

Preparation of Basic Ingredients The compounds of Formulation 1 were each weighed, and these compounds were put in a pot mill together with a plurality of alumina balls and water of 2.5 and stirred and mixed for 15 hours to obtain a mixture.

Here, the weight (g) of each compound of the formulation 1 is the compositional formula of the basic component {(Ba _1-WX Ca _W Sr _X ) 0} _K (Ti _1-yz Zr _y R _z ) O _{2-z / 2} is the value obtained by calculation so that {(Ba _0.85 Ca _0.07 Sr _0.08 ) O} _1.01 (Ti _0.88 Zr _0.10 Ho _0.02 ) O _1.99 (1).

Next, the mixture was placed in a stainless pot and dried at 150 ° C. for 4 hours using a hot air drier, the dried mixture was coarsely crushed, and the coarsely pulverized mixture was used in a tunnel furnace in the atmosphere to about The powder was calcined at 1200 ° C. for 2 hours to obtain powder of the basic component having the composition represented by the composition formula (1).

Preparation of Additive Components In addition, the compounds of Formulation 2 were each weighed, and these compounds were placed in a polyethylene pot and a plurality of alumina balls and 3
It was added together with 00 ml of alcohol and mixed by stirring for 10 hours to obtain a mixture.

Here, the weight (g) of each compound of the formulation 2 is a value obtained by calculation so that the composition of B ₂ O ₃ is 1 mol%, SiO ₂ is 50 mol%, and Li ₂ O is 49 mol%. Is.

Next, the mixture is calcined in the atmosphere at a temperature of about 1000 ° C. for 2 hours, put in an alumina pot together with a plurality of alumina balls and 300 ml of water, pulverized for 15 hours, and then at 150 ° C. for 4 hours. It was dried to obtain powder of the additive component having the above composition.

Preparation of Slurry Next, 100 parts by weight (1000 g) of the basic component,
2 parts by weight (20 g) of the above-mentioned additional components were put into a ball mill, and further, 15% by weight of an organic binder and 50% by weight of water were added to the total weight of these basic components and additional components, and these were mixed. And pulverized to obtain a slurry as a raw material of the dielectric ceramic composition.

Here, the organic binder used was an aqueous solution of acrylic acid ester polymer, glycerin and condensed phosphate.

Formation of unsintered porcelain sheet Next, the slurry was placed in a vacuum defoaming machine for defoaming treatment,
The defoamed slurry was applied on a polyester film with a reverse coater to a predetermined thickness, and the applied slurry was applied together with the polyester film to 1
It was heated at 00 ° C. and dried to obtain a long unsintered porcelain sheet having a thickness of about 25 μm. Then, this long unsintered porcelain sheet was cut to obtain a 10 cm square unsintered porcelain sheet.

Preparation and Printing of Conductive Paste Also, 10 g of nickel powder having an average particle size of 1.5 μm, 0.9 g of ethyl cellulose and 9.1 g of butyl carbitol.
What was dissolved in was put in a stirrer and stirred for 10 hours,
A conductive paste for internal electrodes was obtained.

Then, a pattern (length 14 mm, width 7 mm) made of this conductive paste is formed on one surface of the green ceramic sheet.
0 pieces were formed by the screen printing method and dried.

Lamination of Unsintered Porcelain Sheet Next, two sheets of this unsintered porcelain sheet were laminated with the side on which the pattern made of the conductive paste was formed facing up. At the time of this lamination, the patterns made of the conductive paste were shifted by about half in the longitudinal direction between the adjacent upper and lower unsintered porcelain sheets.

Then, four unsintered porcelain sheets each having a thickness of 60 μm were laminated on each of the upper and lower surfaces of the laminated body as described above to obtain a laminated body.

Next, at a temperature of about 50 ° C., a load of about 40 tons is applied to this laminate at a temperature of about 50 ° C. to bond the unsintered porcelain sheets constituting this laminate to each other. Let Then, this laminate was cut into a lattice shape to obtain 50 laminate chips.

Firing of Laminated Chip Next, the laminated chip is put into a furnace capable of performing atmospheric firing, the inside of the furnace is set to an air atmosphere, the temperature is raised to 600 ° C. at a rate of 100 ° C./h, and the unsintered porcelain sheet is placed. The organic binder was removed by burning.

After that, the atmosphere in the furnace is changed from the atmospheric atmosphere to the reducing atmosphere {H
₂ (2% by volume) + N ₂ (98% by volume)}, the temperature inside the furnace was raised from 600 ° C. to 1120 ° C. at a rate of 100 ° C./h, and the temperature of 1120 ° C. was maintained for 3 hours, After that, the temperature is lowered at a rate of 100 ° C./h, the atmosphere in the furnace is changed to an atmospheric atmosphere (oxidizing atmosphere), and the temperature of 600 ° C. is set to 3
Oxidation treatment was performed by holding for 0 minute, and then cooled to room temperature to obtain a laminated sintered body chip.

Formation of External Electrodes Next, among the opposite side surfaces of this laminated sintered body chip,
By forming a pair of external electrodes on the side surfaces where the ends of the internal electrodes are exposed, three dielectric ceramic layers 1 as shown in FIG. 1 are formed.
2, 12, 12 and a pair of external electrodes 16, 1 at the end of a laminated sintered body chip 15 composed of two layers of internal electrodes 14, 14.
A laminated ceramic capacitor 10 having No. 6 formed was obtained.

Here, the external electrode 16 is formed by applying a conductive paste composed of zinc, glass frit, and vehicle to the side surface, drying the conductive paste, and
The zinc electrode layer 18 is baked in the atmosphere at a temperature of 550 ° C. for 15 minutes to form a zinc electrode layer 18, and a copper layer 20 is formed on the zinc electrode layer 18 by an electroless plating method. The Pb—Sn solder layer 22 is formed by the above process.

The dielectric ceramic layer 12 of the multilayer ceramic capacitor 10
Has a thickness of 0.02 mm, and the facing area of the pair of internal electrodes 14, 14 is 5 mm × 5 mm = 25 mm ² . The composition of the dielectric ceramic layer 12 after sintering is substantially the same as the composition of the mixture of the basic component and the additive component before sintering.

Measurement of Electrical Characteristics Next, the electrical characteristics of the laminated ceramic capacitor 10 are measured,
When the average value was obtained, as shown in Table 1, the relative permittivity ε _s was 17,600, the tan δ was 1.7%, and the resistivity ρ.
Was 2.36 × 10 ⁶ MΩ · cm.

The electrical characteristics were measured as follows.

(A) The relative permittivity ε _s is measured by measuring the capacitance under the conditions of a temperature of 20 ° C., a frequency of 1 kHz, and a voltage (effective value) of 1.0 V, and the measured value and the facing area of the pair of internal electrodes 14, 14. (25
mm ² ) and the thickness (0.02 mm) of the dielectric ceramic layer 12 between the pair of internal electrodes 14, 14 and calculated.

(B) Dielectric loss tan δ (%) is the dielectric constant ε described above.
It was measured under the same conditions as in the case of _s measurement of.

(C) Resistivity ρ (MΩ · cm) is D at 20 ℃
After applying C100V for 1 minute, a pair of external electrodes 1
The resistance value between Nos. 6 and 16 was measured and calculated based on the measured value and the dimension.

Above, No. Although the sample No. 1 was described, 2-8
Also for the sample of No. 5, except that the composition of the basic component and the additive component was changed as shown in the left column of Table 1 and the firing temperature in the reducing atmosphere was changed as shown in the right column of Table 1,
o. A laminated porcelain capacitor was prepared by the same method as that of Sample 1 and the electrical characteristics were measured by the same method. No. 1
The firing temperatures and the electrical characteristics of the samples Nos. To 85 are shown in the right column of Table 1.

In Table 1, the 1-w-x column shows the ratio of the number of Ba atoms in the composition formula of the basic component, the w column shows the ratio of the number of Ca atoms in the composition formula of the basic component, the column of x. Has a ratio of the number of Sr atoms in the composition formula of the basic component of 1-yz
In the column, the ratio of the number of Ti atoms in the composition formula of the basic component, in the column of y is the ratio of the number of atoms of Zr in the composition formula of the basic component, and in the column of z, the R ratio in the composition formula of the basic component. The ratio of the number of atoms is in the column of k in the composition formula of the basic component.
The proportion of {(Ba _1-x Ca _W Sr _X ) O} is shown.

Also, Sc, Y, Gd, Dy, Ho, Er, Y in the column of z
b shows the content of R in the composition formula of the basic component, each element column shows the ratio of the number of atoms of these elements, and the total column shows the number of atoms of these elements. The sum of the proportions (z value) is shown.

Further, the addition amount in the column of the content of the added component is shown in parts by weight with respect to 100 parts by weight of the basic component.

In addition, No. Experiments using the samples 1 to 15 revealed the proper range of glass as an additive component, and No. Experiments using the samples of Nos. 16 to 27 clarified the appropriate range of the addition amount of glass as an additive component, and No. Experiments using the samples Nos. 28 to 39 revealed an appropriate range of the w value, which is the ratio of the number of Ca atoms, and No. Experiments using the samples of Nos. 40 to 55 revealed appropriate ranges of the x value, which is the ratio of the number of Sr atoms, and the y value, which is the ratio of the number of Zr atoms, and No. Experiments using the samples of Nos. 56 to 64 revealed the influence of the difference in the type of R.
Experiments using the samples Nos. 65 to 75 revealed an appropriate range of the z value, which is the ratio of the number of R atoms, and No. Experiments with samples 76-85 reveal the proper range of k, which is the proportion of {(Ba _1-x Ca _w Sr _x ) O}.

As is clear from Table 1, according to the sample according to the present invention, the relative dielectric constant ε _s is 7,000 or more and the dielectric loss tan δ is obtained by firing at 1200 ° C. or less in the non-oxidizing atmosphere.
Of 2.5% or less and a resistivity ρ of 1 × 10 ⁶ MΩ · cm or more, a ceramic capacitor provided with a dielectric ceramic composition having electrical characteristics can be obtained.

On the other hand, No. 12-16, 21, 22, 22, 27, 3
3,39,40,45,53,55,65,70,7
According to the 1,75,76,80,81 and 85 samples,
It is not possible to obtain a porcelain capacitor having the desired electrical characteristics. Therefore, these No. Samples are outside the scope of the present invention.

Next, the reasons for limiting the composition range of the dielectric ceramic composition used in the ceramic capacitor according to the present invention will be described with reference to the experimental results shown in Table 1.

First, the ratio of the number of Ca atoms in the composition formula of the basic component, that is, the value of w will be described.

The value of w is the sample No. 32 and 38, 0.
In the case of No. 27, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 33 and 39, in the case of 0.30, the sintering temperature becomes as high as 1250 ° C., and the relative permittivity ε _s becomes less than 7,000. Therefore, w
Has an upper limit of 0.27.

Further, Ca has a function of flattening the temperature characteristics and a function of improving the resistivity ρ, but even if the value of w is zero, a sintered body having desired electrical characteristics can be obtained. Therefore, w
The lower limit of is zero.

Next, the value of x, which is the ratio of the number of atoms of Sr in the composition formula of the basic component, and the value of y, which is the ratio of the number of atoms of Zr, are
The case where the relational expression is represented by the value of 0.6x + y will be described.

The value of the relational expression 0.6x + y is the sample No. As shown in No. 46, when it is 0.05, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 40, in the case of 0.035, the relative dielectric constant ε _s becomes less than 7,000. Therefore, the lower limit value of the relational expression 0.6x + y is 0.
05.

On the other hand, the value of the relational expression 0.6x + y is the sample No. 52,5
As shown in Fig. 4, in the case of 0.260 and 0.258, a sintered body having desired electrical characteristics can be obtained,
Sample No. As shown in 53 and 55, when the value exceeds 0.26 and becomes 0.290 and 0.285, the relative permittivity ε
_s is less than 7,000. Therefore, the relational expression 0.6x + y
Has an upper limit of 0.26.

However, even if the value of the relational expression 0.6x + y is 0.26 or less, the sample No. As shown in 45, when the value of x exceeds 0.37 and becomes 0.40, the relative permittivity ε _s is 700.
It becomes less than 0. Therefore, the upper limit of the relational expression 0.6x + y is 0.26, but at the same time, the upper limit of x must be 0.37.

Note that Sr and Zr represented by x and y have the same effect of shifting the Curie point to the low temperature side and increasing the relative dielectric constant at room temperature, and 0 <x ≦ 0.37 and 0 <y <0. Two
Within the range of 6 and 0.05 ≦ 0.6x + y ≦
It can be used in a range satisfying 0.26.

Next, the ratio of the number of R atoms in the composition formula of the basic component,
That is, the value of z will be described.

The value of Z is the sample No. 66 and 72, 0.
In the case of 002, a sintered body having desired electrical characteristics can be obtained. As shown by 65 and 71, in the case of 0.001, the dielectric loss tan δ is significantly deteriorated, and the resistivity ρ is also less than 1 × 10 ³ MΩ · cm. Therefore, the lower limit value of z is 0.002.

On the other hand, the value of z is the sample No. As shown in Nos. 69 and 74, in the case of 0.04, a sintered body having desired electrical characteristics can be obtained. As shown in 70 and 75, when 0.06, the firing temperature is 1250 ° C.
However, a dense sintered body cannot be obtained. Therefore, the upper limit of z is 0.04.

The R components Sc, Y, Dy, Ho, Er, and Yb work almost in the same manner, and similar results can be obtained by using one selected from these or by using a plurality of them. .

Next, the ratio of {(Ba _1-WX Ca _W Sr _X ) O} in the composition formula of the basic component, that is, the value of k will be described.

The value of k is the sample No. As shown in 77 and 82, 1.
In the case of No. 00, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 76 and 81, when 0.99, the resistivity ρ is 1 × 10 ⁶ MΩ ·
If it is less than cm, it will be significantly lower. Therefore, the lower limit value of k is 1.00.

On the other hand, the value of k is the sample No. As shown in Nos. 79 and 84, in the case of 1.04, a sintered body having desired electric characteristics can be obtained. As shown in 80 and 85, in the case of 1.05, a dense sintered body cannot be obtained. Therefore, the upper limit of k is 1.04.

Next, the addition amount of the additive component will be described.

The addition amount of the additive component is the same as the sample No. As shown in 17 and 23, when the amount of the basic component is 0.2 parts by weight with respect to 100 parts by weight, a sintered body having desired electrical characteristics can be obtained by firing at 1190 to 1200 ° C. If the addition amount of the additive component is zero, the sample No. As shown in 16 and 22, even if the firing temperature is 1250 ° C., a dense sintered body cannot be obtained. Therefore, the lower limit of the additive component is
It is 0.2 parts by weight with respect to 100 parts by weight of the basic component.

On the other hand, the addition amount of the additive component is the same as the sample No. As shown in 20 and 26, when 5 parts by weight is added to 100 parts by weight of the basic component, a sintered body having desired electrical characteristics can be obtained, but the addition amount of the additional component is No. 21 and 27, the relative permittivity ε _s is less than 7,000 when the amount is 7 parts by weight with respect to 100 parts by weight of the basic component. Therefore, the upper limit of the added amount of the additive component is 5 parts by weight with respect to 100 parts by weight of the basic component.

Next, a preferable composition range of the additive component will be described.

The preferable composition range of the additive component is B ₂ O ₃ -S in FIG.
It can be determined based on a triangular diagram showing the composition ratio of iO ₂ —Li ₂ O.

The first point A in the triangular diagram is the sample No. 1 has a composition of B ₂ O ₃ of 1 mol%, SiO ₂ of 50 mol%, and Li ₂ O of 49 mol%. No. ₂ has a composition of B ₂ O ₃ of 50 mol%, SiO ₂ of 1 mol%, and Li ₂ O of 49 mol%. B ₂ O of 3
₃ is 80 mol%, SiO ₂ is 1 mol%, Li ₂ O is 19 mol%.
The fourth point D indicates the sample No. B of 4
89 mol% of ₂ O _3, 10 mol% of SiO ₂ , Li ₂ O
Indicates a composition of 1 mol%, and the fifth point E is sample No. 5
B ₂ O ₃ of 19 mol%, SiO ₂ of 80 mol%, Li
₂ O shows a composition of 1 mol%, and the sixth point F is sample N
o. B ₂ O _{3 of} 6 is 1 mol%, SiO ₂ is 80 mol%,
Li ₂ O has a composition of 19 mol%.

The additive components of the sample belonging to the composition range of the present invention are within a range surrounded by six straight lines connecting points A to F of the first to sixth points in the triangular diagram shown in FIG. 2 in this order.

When the composition of the additive component is within this range, a sintered body having desired electrical characteristics can be obtained. On the other hand, sample No. If the composition of the additive component is outside the range specified by the present invention, as in Nos. 12 to 15, a dense sintered body cannot be obtained.

[Effects of the Invention] According to the present invention, the composition of the dielectric ceramic composition forming the dielectric layer of the ceramic capacitor is configured as described above. Therefore, it is possible to perform the firing at 1200 ° C. or less in a non-oxidizing atmosphere. Despite that, the relative permittivity ε _s is 7000 to 1
It was possible to dramatically improve it to 9400, and thus it was possible to reduce the size and capacity of the porcelain capacitor.

Since it has become possible to reduce the size and capacity of the porcelain capacitor, it is possible to reduce the cost of the porcelain capacitor in combination with the use of a conductive paste of a base metal such as nickel for forming the internal electrodes. Became.

[Brief description of drawings]

FIG. 1 is a sectional view of a laminated ceramic capacitor according to an embodiment of the present invention, and FIG. 2 is a triangular diagram showing a composition range of additive components. 12 ... Dielectric porcelain layer, 14 ... Internal electrode, 15 ... Laminated sintered body chip, 16 ... External electrode, 18 ... Zinc electrode layer, 20 ... Copper layer, 22 ... Pb-Sn solder layer

Claims (2)

[Claims] 1. A porcelain capacitor comprising a dielectric porcelain layer made of a dielectric porcelain composition and at least two internal electrodes sandwiching the dielectric porcelain layer, wherein the dielectric porcelain composition comprises: It is composed of a mixture of 100.0 parts by weight of the basic component and 0.2 to 5.0 parts by weight of the additive component, and the basic component is {(Ba _1-WX Ca _W Sr _X ) 0}. _K (Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
one or more elements selected from b, Tb, Tm and Lu, w, x, y, z, k are: 0 ≦ w ≦ 0.27 0 <x ≦ 0.37 0 <y <0 .26 0.05 ≦ 0.6x + y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04), wherein the additive components are B ₂ O ₃ and SiO ₂ And Li ₂ O, the composition range of B ₂ O ₃ , SiO _2, and Li ₂ O is a triangle diagram showing these compositions in mol%, where B ₂ O ₃ is 1 mol%, SiO ₂ is 50 mol%,
A first point A showing a composition of Li ₂ O of 49 mol%, B ₂ O ₃ of 50 mol%, SiO ₂ of 1 mol%,
A second point B showing a composition of 49 mol% of Li ₂ O, 80 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
The third point c showing the composition of Li ₂ O of 19 mol%, and the third point c showing the composition of B ₂ O ₃ of 89 mol%, the SiO ₂ of 10 mol%, and the Li ₂ O of 1 mol%. Point D of 4
And a fifth point E indicating a composition in which B ₂ O ₃ is 19 mol%, SiO ₂ is 80 mol%, and Li ₂ O is 1 mol%.
And B ₂ C ₃ is 1 mol%, SiO ₂ is 80 mol%,
A ceramic capacitor characterized in that the Li ₂ O is in a region surrounded by six straight lines connecting in this order with a sixth point F indicating a composition of 19 mol%. 2. A step of preparing a mixture of unsintered porcelain powder, a step of forming an unsintered porcelain sheet of the mixture, and a step of forming at least two or more conductive paste films of the unsintered porcelain sheet. And a step of heat-treating the laminate in a non-oxidizing atmosphere, and a step of heat-treating the laminate subjected to the heat treatment in an oxidizing atmosphere. The mixture of the porcelain powder for binding comprises 100.0 parts by weight of the basic component and 0.2 to 5 parts by weight of the additional component, and the basic component is ((Ba _1-WX Ca _W Sr _X ) 0 } _K (Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
one or more elements selected from b, Tb, Tm and Lu, w, x, y, z, k are: 0 ≦ w ≦ 0.27 0 <x ≦ 0.37 0 <y <0 .26 0.05 ≦ 0.6x + y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04), wherein the additive components are B ₂ O ₃ and SiO ₂ And Li ₂ O, the composition range of B ₂ O ₃ , SiO _2, and Li ₂ O is a triangle diagram showing these compositions in mol%, where B ₂ O ₃ is 1 mol%, SiO ₂ is 50 mol%,
A first point A showing a composition of Li ₂ O of 49 mol%, B ₂ O ₃ of 50 mol%, SiO ₂ of 1 mol%,
A second point B showing a composition of 49 mol% of Li ₂ O, 80 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A third point C showing a composition of Li ₂ O of 19 mol%, a third point C showing a composition of B ₂ O ₃ of 89 mol%, a content of SiO ₂ of 10 mol%, and a composition of Li ₂ O of 1 mol%. Point D of 4
And a fifth point E indicating a composition in which B ₂ O ₃ is 19 mol%, SiO ₂ is 80 mol%, and Li ₂ O is 1 mol%.
And B ₂ O ₃ is 1 mol%, SiO ₂ is 80 mol%,
A method for manufacturing a porcelain capacitor, wherein the Li ₂ O is in a region surrounded by six straight lines connecting in this order with a sixth point F having a composition of 19 mol%.