JPH0614496B2 - Porcelain capacitor and method of manufacturing the same - Google Patents

Description

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

[Prior Art] A laminated porcelain capacitor is manufactured by printing a conductive paste in a desired pattern on an unsintered porcelain sheet (green sheet) made of a derivative porcelain raw material powder, stacking a plurality of the pastes and press-bonding them in an oxidizing atmosphere. It 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.

In order to solve this problem, Japanese Patent Publication No. 60-20851 relating to the applicant of the present invention discloses that (Ba _x Ca
_y Sr ₂ ) O} _k (Ti _n Zr _1-7 ) O _{2 as} a basic component, 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 an additive component composed of ₂ O ₃ , SiO ₂ and Li ₂ O is disclosed.

In addition, in Japanese Patent Laid-Open No. 61-1747405, {(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 dielectric constant ε of the dielectric ceramic composition forming the dielectric layer of the multilayer ceramic capacitor, the dielectric ceramic composition of the dielectric ceramic composition disclosed in each of 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-x Ca _x ) O} _k (Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
b, Tb, Tm, and one or more elements selected from Lu, x, y, z, and k are 0 ≦ x ≦ 0.27 0.05 ≦ y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04, and the additive components are Li ₂ O, SiO ₂ and MO (however, MO
Is one or more oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the Li ₂ O, the SiO ₂ and the MO is such that the composition is mol%. In the triangular diagram shown by, the Li ₂ O is 1 mol%, the SiO ₂ is 80 mol%,
A first point A showing a composition in which the MO is 19 mol%, 1 mol% of the Li ₂ O and 39 mol% of the SiO ₂ ,
A second point B showing a composition of the MO of 60 mol%, and a third point C showing a composition of the Li ₂ O of 30 mol%, the SiO ₂ of 30 mol%, and the MO of 40 mol%. A fourth point D showing a composition of 50 mol% of Li ₂ O, 50 mol% of SiO _{2, and} 0 mol% of MO, and 20 mol% of Li ₂ O and 80 mol of SiO ₂ %, And the fifth point E indicating the composition where MO is 0 mol%, and is in the region surrounded by five straight lines connecting in this order.

Here, the ratio of the number of Ca atoms in the composition formula of the basic component, that is, the value of x is 0 ≦ X ≦ 0.27,
When the value of is 0 ≦ x ≦ 0.27, a sintered body having desired electrical characteristics can be obtained, but when it exceeds 0.27, the firing temperature is as high as 1250 ° C. And the relative dielectric constant ε _s is also less than 7,000.

Further, the ratio of the number of atoms of Zr in the composition formula of the basic component, that is, the value of y is set to 0.05 ≦ y ≦ 0.26, because the value of y is 0.05 ≦ y ≦ 0.26. In this case, a sintered body having desired electrical characteristics can be obtained,
This is because the relative permittivity ε becomes less than 7,000 when out of this range.

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-x Ca _x ) O} in the composition formula of the basic component, that is, the value of k is 1.00 ≦ k ≦ 1.04 is expressed by k
When the value of is 1.00 ≦ k ≦ 1.04, a sintered body having desired electrical characteristics can be obtained, but 1.0
When it becomes less than 0, the resistivity ρ is 1 × 10 ⁴ MΩ ·
This is because if it is less than 10 cm, it is significantly lowered, and if 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 components, oxides other than those shown in the examples may be used, or hydroxides or other chemicals may be used.

Next, the addition amount of the additive component was set to 0.2 to 5.0 parts by weight with respect to 100 parts by weight of the basic component, because when the addition amount of the additive component was within this range, 1190 to 1200 ° 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 Li ₂ O, SiO ₂ and MO in mol%, the composition of the additive component is set within the range surrounded by the five straight lines connecting the points A to E in this order. , If the composition of the additive component is within this range, a sintered body having desired electrical characteristics can be obtained, but if the composition of the additive component is outside this range, a dense sintered body can be obtained. Because you cannot get it.

The MO component is BaO, SrO, CaO, MgO,
Any one of ZnO may be used, or an appropriate ratio may be used.

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 compound 1 is calculated by the compositional formula of the basic component {(Ba _1-x Ca _x ) O} _k (Ti _1-yz Zr _y R _z ) O _{2-z / 2. , {(Ba 0.93 Ca 0.07)} O} 1.01 - a value was calculated as the _{(Ti 0.83 Zr 0.15 Dy 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 dryer, the dried mixture was roughly crushed, and the roughly crushed mixture was placed in the atmosphere using a tunnel furnace. Then, the powder was calcined at about 1200 ° C. for 2 hours to obtain a 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
The mixture 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 1 mol% Li ₂ O, 80 mol% SiO ₂ , and 19 mol% MO.
{BaO (3.8 mol%) + CaO (9.5 mol%) + MgO (5.7
It is a value obtained by calculation so as to have a composition of (mol%)}.

The proportion of BaO, CaO, and MgO in MO is such that BaO is 20 mol%, CaO is 50 mol%, and M is
gO is 30 mol%.

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 above slurry was placed in a vacuum defoamer for defoaming treatment, and the defoamed slurry was applied to a polyester film at a predetermined thickness using a reverse coater, and this application was performed. The resulting slurry is used together with this polyester film for 10
It was heated at 0 ° 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) 5 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 1150 ° C. at a rate of 100 ° C./h, and the temperature of 1150 ° 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,
A pair of external electrodes are formed on the side surfaces where the ends of the internal electrodes are exposed, and three layers of 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 15600, tan δ was 1.4%, and the resistivity ρ was
Was 3.43 × 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 above dielectric constant ε _s
The measurement was performed under the same conditions as in the case of measurement.

(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.

As described above, the sample No. The sample No. 1 has been described. 2 to
Also for 87, 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, except for Sample N.
o. A laminated porcelain capacitor was prepared by the same method as that of No. 1, and the electrical characteristics were measured by the same method.

Sample No. The electrical characteristics of Nos. 2 to 87 are as shown in the right column of Table 1.

In Table 1, the 1-x column shows the ratio of the number of Ba atoms in the composition formula of the basic component, the x column shows the ratio of the number of Ca atoms in the composition formula of the basic component, 1-y. In the column of -z, the ratio of the number of Ti atoms in the composition formula of the basic component, in the column of y, the ratio of the number of atoms of Zr in the composition formula of the basic component, and in the column of z, the composition ratio of the basic component. The ratio of the number of atoms of R is shown in the column of k in the composition formula of the basic component.
The proportion of {(Ba _1-x Ca _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.

In addition, the amount of addition 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, and in the column of the content of MO, Ba
The proportions of O, SrO, CaO, MgO and ZnO are given in mol%.

As is clear from Table 1, according to the sample according to the present invention, the non-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. 11-16, 24, 29, 30, 3
5,41,47,48,52,53,57,67,7
According to the samples Nos. 2, 73, 77, 78, 82, 83 and 87, it is not possible to obtain a porcelain capacitor having desired electric 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.

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

The value of x is the sample No. 40 and 46, 0.
In the case of No. 27, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 41 and 47, in the case of 0.30, the firing temperature is as high as 1250 ° C., and the relative dielectric constant ε _s is also less than 7,000. Therefore, x
The upper limit of the value of is 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 x is zero, a sintered body having desired electrical characteristics can be obtained. Therefore, x
The lower limit of the value of is zero.

Next, the ratio of the number of Zr atoms in the composition formula of the basic component, that is, the value of y will be described.

The value of y is the sample No. 49 and 54, 0.
In the case of No. 05, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 48 and 53, when 0.03, the relative permittivity ε _s is less than 7,000. Therefore, the lower limit of the value of y is 0.05.

On the other hand, the value of y is the sample No. As shown in Nos. 51 and 56, in the case of 0.26, a sintered body having desired electric characteristics can be obtained. As shown in 52 and 57, in the case of 0.29, the relative permittivity ε _s becomes less than 7,000. Therefore, the upper limit of the value of y is 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. 68 and 74, 0.
In the case of 002, a sintered body having desired electrical characteristics can be obtained. As shown in 67 and 73, 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 of the value of z is 0.002.

On the other hand, the value of z is the sample No. 71 and 76, in the case of 0.04, a sintered body having desired electrical characteristics can be obtained. As shown in 72 and 77, when 0.06, the firing temperature is 1250 ° C.
However, a dense sintered body cannot be obtained. Therefore, the upper limit of the value 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-x Ca _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 79 and 84, 1.
In the case of No. 00, it is possible to obtain a sintered body having desired electrical characteristics. As shown in 78 and 83, when 0.99, the resistivity ρ is 1 × 10 ⁴ MΩ.
If it is less than cm, it will be significantly lower. Therefore, the lower limit of the value of k is 1.00.

On the other hand, the value of k is the sample No. 81 and 86, when 1.04, a sintered body having desired electrical characteristics can be obtained. As shown in 82 and 87, in the case of 1.05, a dense sintered body cannot be obtained. Therefore, the upper limit of the value 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 25 and 31, when 0.2 parts by weight is added to 100 parts by weight of the basic components, 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 24 and 30, even if the firing temperature is 1250 ° C., a dense crystal 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 Nos. 28 and 34, 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. No. As shown in 29 and 35, in the case of 7 parts by weight with respect to 100 parts by weight of the basic component, the relative dielectric constant ε _s is less than 7,000. 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 Li ₂ O—S in FIG.
It can be determined based on a trigonometric diagram showing the composition ratio of iO ₂ -MO.

The first point A in the triangular diagram is the sample No. No. 1 has a composition of 1 mol% of Li ₂ O, 80 mol% of SiO ₂ , and 19 mol% of MO, and the second point B is sample No. No. ₂ has a composition of 1 mol% Li ₂ O, 39 mol% SiO ₂ , and 60 mol% MO, and the third point C is Sample No. Li ₂ O of 3 is 30
Mol%, SiO ₂ 30 mol% and MO 40 mol% are shown in the composition. 4 Li ₂ O is 5
The composition has a composition of 0 mol%, SiO ₂ of 50 mol% and MO of 0 mol%. 5 Li ₂ O is 2
The composition is 0 mol%, SiO ₂ is 80 mol%, and MO is 0 mol%.

The added component of the sample belonging to the composition range of the present invention is within a range surrounded by five straight lines connecting points A to E of the first to fifth points in the triangular diagram shown in FIG.

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 out of the range specified in the present invention as in Nos. 11 to 16, a dense sintered body cannot be obtained.

The MO component is, for example, the sample No. It may be any one of BaO, SrO, CaO, MgO, and ZnO as shown in Nos. 17 to 21, or may have an appropriate ratio as shown in other samples.

[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, its relative permittivity ε _s is 7000-
It can be dramatically improved to 19400, and therefore
It has become possible to reduce the size and capacity of porcelain capacitors.

Since it has become possible to reduce the size and capacity of porcelain capacitors, it is possible to reduce the cost of porcelain capacitors in combination with the use of a conductive paste of a base metal such as nickel for forming 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 consists 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-x Ca _x ) O} _k ( Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
b, Tb, Tm, and one or more elements selected from Lu, x, y, z, and k are 0 ≦ x ≦ 0.27 0.05 ≦ y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04, and the additive components are Li ₂ O, SiO ₂ and MO (however, MO
Is one kind or two or more kinds of oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the Li ₂ O, the SiO ₂ and the MO is such that the composition is mol%. In the triangular diagram shown by, the Li ₂ O is 1 mol%, the SiO ₂ is 80 mol%,
A first point A showing a composition in which the MO is 19 mol%, 1 mol% of the Li ₂ O and 39 mol% of the SiO ₂ ,
A second point B showing a composition of the MO of 60 mol%, and a third point C showing a composition of the Li ₂ O of 30 mol%, the SiO ₂ of 30 mol%, and the MO of 40 mol%. A fourth point D showing a composition of 50 mol% of Li ₂ O, 50 mol% of SiO _{2, and} 0 mol% of MO, and 20 mol% of Li ₂ O and 80 mol of SiO ₂ %, And a fifth point E indicating the composition of MO of 0 mol% is in the region surrounded by five straight lines connecting in this order. 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 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 composed 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-x Ca _x ) O} _k (Ti _1-yz Zr _y R _z ) O _{2-z / 2} (where R is Sc, Y, Gd, Dy, Ho, Er, Y
b, Tb, Tm, and one or more elements selected from Lu, x, y, z, and k are 0 ≦ x ≦ 0.27 0.05 ≦ y ≦ 0.26 0.002 ≦ z ≦ 0.04 1.00 ≦ k ≦ 1.04, and the additive components are Li ₂ O, SiO ₂ and MO (however, MO
Is one or more oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the Li ₂ O, the SiO ₂ and the MO is such that the composition is mol%. In the triangular diagram shown by, the Li ₂ O is 1 mol%, the SiO ₂ is 80 mol%,
A first point A showing a composition in which the MO is 19 mol%, 1 mol% of the Li ₂ O and 39 mol% of the SiO ₂ ,
A second point B showing a composition of the MO of 60 mol%, and a third point C showing a composition of the Li ₂ O of 30 mol%, the SiO ₂ of 30 mol%, and the MO of 40 mol%. A fourth point D showing a composition of 50 mol% of Li ₂ O, 50 mol% of SiO _{2, and} 0 mol% of MO, and 20 mol% of Li ₂ O and 80 mol of SiO ₂ %, The MO is in a region surrounded by five straight lines connecting the fifth point E, which indicates a composition of 0 mol%, in this order, and a method for manufacturing a porcelain capacitor.