JPH03278414A - Porcelain capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve relative permittivity by mixing 100 pts.wt. of specific basic component, and 0.2-5 pts.wt. of specific additive component of a specific range of a triangular diagram of mol% of composition range, and firing the mixture to form a dielectric porcelain composition. CONSTITUTION:100 pts.wt. of basic component represented by formula I and 0.2-5 pts.wt. of additive component containing B-excision O3, SiO2 and MO (MO is metal oxide of one or more types selected from BaO, SrO, CaO, MgO and ZnO) are mixed and fired to form dielectric porcelain composition. The composition range of the additive component is disposed in a range surrounded by straight lines for sequentially coupling points A-B-C-D-E-F-A of a triangular diagram shown by mole % of the composition range of the additive component, and hence its relative permittivity can be set to 3000 or more. In formula I, M; Mg and/or Zn, R; one or more types or metal elements selected from Sc, Y, Gd, Dy, Ho, Er, Yb. Letters k, x, z; numerical values for satisfying formulae II, III, IV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a single-layer or laminated structure IIA capacitor comprising a dielectric ceramic layer sandwiched between at least two internal electrodes, and a method for manufacturing the same. be.

[Conventional technology] Traditionally, when manufacturing laminated porcelain capacitors.

A conductive paste of noble metal such as platinum or palladium is printed in a desired pattern on an unsintered porcelain sheet (green sheet) made of dielectric porcelain raw material powder, multiple sheets are stacked and pressed together, and heated at 1300°C in an oxidizing atmosphere. ~160
It was fired at 0°C.

Through this firing, the unsintered porcelain sheet made of the dielectric porcelain raw material powder becomes a dielectric porcelain layer, and the conductive paste of noble metal such as platinum or palladium becomes an internal electrode.

As mentioned above, if a conductive paste containing a noble metal such as platinum or palladium is used as the main component, the intended internal electrode can be formed even if it is fired at a high temperature of 1300°C to 1600°C in an oxidizing atmosphere. Obtainable.

However, since noble metals such as platinum-5-palladium are expensive, the cost of multilayer ceramic capacitors has inevitably increased.

As a solution to the above-mentioned problem, the applicant's patent publication No. 61. -14607 publication, (
A basic component consisting of B a *-m M 1110 kT I Ox (where M is Mg and/or Zn), and L
A dielectric ceramic composition is disclosed that includes an additive component consisting of i z O and S i O*.

In addition, Japanese Patent Publication No. 61-14608 discloses that the dielectric ceramic composition described in Japanese Patent Publication No. 61-14607 is
1 z O and S i Ox instead.

LL2O3Sin, and MO (however, MO is Bad, C
A dielectric ceramic composition is disclosed that includes an additive component consisting of one or more metal oxides selected from aO and SrO.

In addition, in Japanese Patent Publication No. 14609/1983, (B am
-++-y M, r-ylob Ti Ox (However, M is Mg and/or Zn, L is Sr and/or Ca
A dielectric ceramic composition is disclosed that includes a basic component consisting of L i t O and 5in2.

Further, in Japanese Patent Publication No. 61-14610, Liz O,
B2O3 and MO (however, MO is Bad, CaO and S
one or more metal oxides selected from rO)
A dielectric ceramic composition is disclosed that includes an additive component consisting of.

In addition, in Japanese Patent Publication No. 14611/1987, (B am
-x M, lO, T t Ox (However, M is Mg.

one or more metal elements selected from Zn, Sr and Ca), and E2O3 and Si
A dielectric ceramic composition is disclosed that includes an additive component consisting of Oz.

In addition, in Japanese Patent Publication No. 1595/1983, (Bak-
x MIIIOII T x Ox (However, M 4
f M g .

one or more metal elements selected from Z n + S r and Ca), B2O3 and MO (where MO is Bao);

A dielectric ceramic composition containing an additive component consisting of one or more metal oxides selected from MgO, ZnO, SrO, and CaO is disclosed.

In addition, Japanese Patent Publication No. 1596/1982 discloses 820% of the dielectric ceramic composition described in Japanese Patent Publication No. 1595/1982.
8 and B2O- instead of MO.

S i O, x and MO (However, MO is B ao.

A dielectric ceramic composition containing an additive component consisting of one or more metal oxides selected from MgO, ZnO, SrO, and CaO is disclosed.

If the dielectric ceramic composition disclosed in these documents is used as a dielectric layer, it can be heated to 1200°C in a reducing atmosphere.
Porcelain capacitors can be obtained by firing at the following temperatures:
Moreover, the relative permittivity of the dielectric ceramic composition is 2000 or more, and the temperature change rate of the relative permittivity is -l from -25°C to +85°C.
It can be in the range of 0% to +10%.

[Problems to be solved by the invention] By the way, with the increasing density of electronic circuits in recent years,
There is a strong demand for smaller ceramic capacitors, and it has been desired to develop a ceramic capacitor equipped with a dielectric ceramic composition having a dielectric constant higher than that disclosed in the above-mentioned publications. .

In addition, since ceramic capacitors are conveniently used in various environments, dielectric ceramic compositions with a smaller rate of change in dielectric constant over a wider temperature range than the dielectric ceramic compositions disclosed in the above-mentioned publications are used. There was a desire to develop a ceramic capacitor with this feature.

Therefore, the object of the present invention is to
Although it can be obtained by firing at temperatures below 200°C, it has a relative dielectric constant of 3000 or more and a dielectric loss tan δ of 2.
．． 5% or less, resistivity ρ is 1 x 10'MΩ・cm or more, and the temperature change rate of relative permittivity is -15% to +15% (based on 25°C) at -55°C to 125°C, -25°C to 85
An object of the present invention is to provide a ceramic capacitor including a dielectric ceramic composition whose temperature ranges from -10% to +10% ($ based on 20°C) and a method for manufacturing the same.

[Means for Solving the Problems] A ceramic capacitor according to the present invention includes a dielectric ceramic layer made of a dielectric ceramic composition, and at least two or more internal electrodes sandwiching the dielectric ceramic layer, The dielectric ceramic composition consists of 100 parts by weight of a basic component and 0.2 to 5 parts by weight of an additive component, and the basic component is (B a 1l-x MIIIOm(T i +-x
Rzlo 2-Z/2 (where M is Mg and/or Zn
, R is Sc.

1 selected from Y, Gd, Dy, Ha, Er and Yb
species or two or more metal elements, k, x, z are 1, 00≦k≦1. 05 0 , 01 ≦x ≦0 , 10 0 , 002 ≦ Z ≦0 , 06), and the additive component is B, 03
and S i O2 and MO (however, MO is Bad, SrO,
One or two selected from CaO, MgO and ZnO
(metal oxide).

The composition ranges of the B2O3, the B2O3, and the MO are represented by B, 0. is 1 mol%, the SiO2 is 80 mol%,
A first point A in which the MO has a composition of 19 mol%, the B2O3 is 1 mol%, the B2O3 is 39 mol%,
a second point B having a composition of 60 mol % of the MO; 29 mol % of the B2O3; 1 mol % of the Sin;
a third point C having a composition of 70 mol% of the MO; 90 mol% of the B2O3; 1 mol% of the Sin;
a fourth dot having a composition of 9 mol% of the MO; 90 mol% of the B2O3; 9 mol% of the SiOx;
A fifth point E has a composition in which the MO is 1 mol%, and a sixth point E has a composition range of 9 mol%, 80 mol%, and 1 mol% of the MO This is within the area surrounded by six straight lines connecting point F in this order.

Here, the value of k is preferably in the range of 1.00≦k≦1.05. When the value of k is less than 1.00, the resistivity ρ is 1.00. X
10' becomes smaller than MO・cm, and the temperature change rate of capacitance ΔC-5s, ΔC1□5 is -15% to +15%
deviated from △C-0. If ΔCas deviates from -10% to +10% and the value of k exceeds 1.05, a dense sintered body cannot be obtained (although the value of 1.00≦k≦
This is because within the range of 1.05, a dense sintered body having desired electrical characteristics can be obtained.

Moreover, the value of X is preferably in the range of 0.01≦x≦0.10. When the value of X is less than 0.01, the temperature change rate of capacitance is △
C-811 deviates from -15% to +15% and the value of X is 0
．． If it exceeds 10, the capacitance temperature change rate ΔC115 will deviate from -10% to +10%, but if the value of X is 0.
This is because in the range of 01≦x≦0.10, a material having desired electrical characteristics can be obtained.

In addition, Mg and Zn, which are M components, act in the same way as f, and 0.
Desired electrical characteristics can be obtained by using one or both of Mg and Zn within a range that satisfies 01≦x≦0.10.

Further, the value of Z is preferably in the range of 0.002≦z≦0.06. If the value of Z is less than 0.002, the temperature change rate ΔC-5s of capacitance deviates from -15% to +15%, ΔC-
2. If the value of Z deviates from -10% to +10% and the value of Z exceeds 0.06, a dense sintered body cannot be obtained. This is because a dense sintered body having desired electrical properties can be obtained.

Furthermore, the R component contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, the temperature
Temperature change rate of capacitance ΔC-6 in the range of ~125°C,
~ΔC1□5 can be easily kept in the range of -15% to +15%, and the temperature change rate of capacitance ΔC-25 to ΔCas in the range of -25°C to 85°C can be reduced to -10%.
This makes it possible to easily keep the capacitance within the range of ~+10%, and to reduce the fluctuation range of the temperature change rate of capacitance in each temperature range.

Moreover, the R component has the effect of increasing the resistivity ρ and the effect of increasing the sinterability.

Note that the R components are Sc, Y, Gd, Dy, and Ha.

Er and Yb work in the same way as a bead, and the same effect can be obtained even if one selected from them is used or a plurality of them are used in combination.

However, the value of 2 is preferably in the range of 0.002≦z≦0.06, regardless of whether there is one type of R component or multiple types of R components.

In addition, in the composition formula showing the basic components, x, z,
Of course, it shows the number of atoms of each element.

In addition, a trace amount of M n O□ (preferably 0.05 to 0
．． A mineralizing agent such as 1% by weight) may be added to improve sinterability. Further, other substances may be added as necessary.

In addition, starting materials for obtaining the basic components may be other than those shown in Examples, such as Bad and SrO.

It may also be an oxide or hydroxide such as CaO or other compounds.

Next, the amount of the additive component added is preferably in the range of 0.2 to 5 parts by weight per 100 parts by weight of the basic component.

If the amount of the additive component is less than 0.2 parts by weight, a dense sintered body cannot be obtained even if the firing temperature is 1250 ° C.
Furthermore, when the amount of the additive component exceeds 5 parts by weight, the dielectric constant ε becomes less than 3000, and the temperature change rate ΔC-5s of capacitance deviates from -15% to +15%, but the additive component This is because when the amount is in the range of 0.2 to 5 parts by weight, desired electrical characteristics can be obtained.

The composition of the additive component is preferably within the region surrounded by six straight lines connecting the first to fifth voices and A to F in the triangular diagram showing the composition ratio of B20--5iO□-MO in mol%.

If the composition of the additive component is outside this range, a dense sintered body cannot be obtained, but if the composition is within this range, a sintered body with desired electrical properties can be obtained. .

Note that the starting materials for the additive components may be other compounds such as oxides and hydroxides.

Next, the method for manufacturing a porcelain capacitor according to the present invention includes the steps of preparing a mixture of unsintered porcelain powder consisting of the above basic components and additive components, and forming an unsintered porcelain sheet consisting of the mixture. a step of forming a laminate in which the unsintered porcelain sheet is sandwiched between at least two conductive paste films; a step of firing the laminate in a non-oxidizing atmosphere; The method includes a step of heat-treating the laminate in an oxidizing atmosphere.

Here, the firing temperature in the non-oxidizing atmosphere can be varied depending on the electrode material.

When using nickel as the internal electrode, the temperature is 1050℃~12
Almost no aggregation of nickel particles occurs in the temperature range of 00°C.

Further, the non-oxidizing atmosphere may be not only a reducing atmosphere such as N2 or CO, but also a neutral atmosphere such as N2 or Ar.

Furthermore, the temperature of the heat treatment in the oxidizing atmosphere can be varied in consideration of the electrode material such as nickel and the oxidation of the ceramic.

Although the temperature of this heat treatment was set to 600°C in the example, it is not limited thereto, and may be any temperature lower than the sintering temperature, preferably in the range of 500°C to 1000°C.

Note that the present invention is of course applicable to general single-layer ceramic capacitors other than multilayer ceramic capacitors.

[Example] First, the preparation method of samples No. 1 in Table 1 and their electrical characteristics will be explained.

The compounds of Formulation 1 were each weighed and mixed for 15 hours to obtain a raw material mixture.

Here, the weight (g) and molar parts of the compound of Formulation 1 are values calculated so that the general formula of the basic components is %.

Next, this raw material mixture was dried at 150° C. for 4 hours, pulverized, and calcined in the air at a temperature of about 1200° C. for 2 hours to obtain a powder of the basic component.

L Otori Tateho 11 In addition, the compounds of Formulation 2 were each weighed and mixed.

300 cc of alcohol was added to this mixture, and the mixture was stirred in a polyethylene pot using an alumina ball for 10 hours, and then pre-calcined in the air at a temperature of 1000° C. for 2 hours.

Here, the weight (g) and molar parts of the compound of formulation 2 are as follows: B snow 03 is 1 mol%, SiO2 is 80 mol%, MO is 1 mol%.
The composition was 9 mol% (BaO (3.8 mol%) + CaO (3.8 mol%) + SrO (3.8 mol%) + Mg0 (3.8 mol%) + ZnO (3.8 mol%)). This is the value obtained by calculating.

Next, the material obtained by this calcining was placed in an alumina pot with 300 cc of water, and an alumina ball was used to
Grind for hours, then dry at 150°C for 4 hours,
A powder of additive components was obtained.

In addition, the contents of MO are Bad and Cab.

As shown in Table 1, the proportions of SrO, MgO and ZnO are all 20 mol%.

Next, 2 parts by weight (20 g) of the above additive components were added to 100 parts by weight (1000 g) of the basic component, and further an aqueous solution of acrylic acid ester polymer glycerin and condensed phosphate was added. An organic binder is added in an amount of 15% by weight based on the total weight of the basic component and additive components, and
0% by weight of water was added, and these were placed in a ball mill to be ground and mixed to prepare a slurry of porcelain raw materials.

- After forming the Shimagi sheet, put the slurry into a vacuum defoaming machine to defoam it, put this slurry into a reverse roll coater, and coat the resulting thin film molded product on a long polyester film. The receiver was continuously taken and dried on the same film by heating at 100° C. to obtain an unsintered porcelain sheet with a thickness of about 25 μm.

This sheet is long, but this is ], Oc
Cut into m-square squares and use.

Preparation of conductive paste On the other hand, conductive paste for internal electrodes has an average particle size of 1.5
10g of μm nickel powder and 0.9g of ethyl cellulose
g was dissolved in 9.1 g of butylcarpitol, and the mixture was placed in a stirrer and stirred for 10 hours. Then, this conductive paste was printed on one side of the unsintered porcelain sheet through a screen having 50 patterns of 14 mm in length and 7 mm in width, and then dried.

Next to the magnetic zero sheet, two unsintered ceramic sheets were laminated with the printed side facing up. At this time, the adjacent upper and lower sheets were arranged so that their printed surfaces were shifted by about half in the longitudinal direction of the pattern. Further, four unsintered porcelain sheets each having a thickness of 60 μm were laminated on the upper and lower surfaces of this laminate.

The laminate was then heated at a temperature of about 50°C for about 40 minutes in the thickness direction.
A load of 0 tons was applied to bond the parts. Thereafter, this laminate was cut into a grid shape to obtain 50 laminate chips.

After forming the layered chips, the laminate chips were placed in a furnace capable of firing in an atmosphere, and heated at 600°C at a rate of 100°C/h in an air atmosphere.
The organic binder was burned.

After that, the atmosphere of the furnace was changed from the atmosphere to H2 (2% by volume) + N.
, (98% by volume). Then, while maintaining the furnace in this reducing atmosphere, the heating temperature of the stacked chips was increased from 600°C to the sintering temperature of 1150°C.
Raise the temperature at a rate of 100°C/h to 1150°C (maximum temperature)
After holding for 3 hours, the temperature was lowered to 600°C at a rate of 100°C/h, the atmosphere was changed to an air atmosphere (oxidizing atmosphere), and 600°C was held for 30 minutes to perform oxidation treatment.
Thereafter, it was cooled to room temperature to obtain a laminated sintered body chip.

Outer 13L pole jυΔ Next, zinc, glass frit, and vehicle (
A conductive paste consisting of a vehicle) was applied and dried, and this was baked in the air at a temperature of 550°C for 15 minutes to form a zinc electrode layer, and then a copper layer was further formed on this using an electroless plating method. , and then on top of this, Pb-
A 5N solder layer was provided to form a pair of external electrodes.

As a result, as shown in FIG. 1, a multilayer ceramic capacitor 10 is obtained in which a pair of external electrodes 16 are formed on a multilayer sintered chip 15 consisting of three dielectric ceramic layers 12 and two internal electrodes 14. It was done.

Here, the external electrode 16 includes a zinc electrode layer 18, a copper layer 20 formed on the zinc electrode layer 18, and a copper layer 20 formed on the zinc electrode layer 18.
and a Pb-3n solder layer 22 formed on top of the Pb-3n solder layer 22.

Note that the dielectric ceramic layer 12 of this multilayer ceramic capacitor 10
The thickness of the dielectric ceramic layer 12 is 0.02 mm, and the opposing area of the pair of internal electrodes 14 is 5 mm x 5 mm = 25 mm.The composition of the dielectric ceramic layer 12 after sintering is determined by mixing the basic components and additive components before sintering. The composition is substantially the same.

After the electric current is constant, the electrical characteristics of the multilayer ceramic capacitor 10 are measured,
The average values were calculated, and as shown in Table 2, the relative dielectric constant ε is 3510, tan δ is 1.2%, resistivity ρ is 4.7 x 10'MΩ・cll, and the capacitance at 25°C is Rate of change in capacitance ΔC at -55℃ and +125℃ based on standard
-ss△C+2g is -11.5%, +6.5%, 20℃
The rate of change in capacitance ΔC46, ΔCas at -25°C and +85°C is -6.5% based on the capacitance of .

-5.2%.

Note that the electrical characteristics were measured in the following manner.

fA) Relative permittivity ε, temperature 20℃, frequency 1, k
Hz, voltage (effective value) 1. The capacitance was measured under OV conditions, and this measured value and the opposing area 2 of the pair of internal electrodes 14 were
5 mm'' and the thickness of the dielectric ceramic layer 12 between the pair of internal electrodes 14 of 0.02 mm.

fi+dielectric loss tan δ (%) was measured under the same conditions as the above-mentioned measurement of relative dielectric constant.

C) Resistivity p (MΩ-cm) of a pair of external electrodes 1 after applying DClooV for 1 minute at a temperature of 20”C
The resistance value between 6 and 6 was measured and calculated based on this measured value and the dimensions.

fD) Temperature characteristics of capacitance: Place the sample in a constant temperature bath, -55°C, -25°C, O'C, +20'C.

+25°C, +40°C, +60’C, +85°C.

At each temperature of +105°C and +125°C, frequency 1.
The capacitance was measured under the conditions of kHz, 1 and pressure (effective value) 1.0 V (7), and the rate of change at each temperature with respect to the capacitance at 20° C. and 25° C. was obtained.

The preparation method of samples No. 1 and their characteristics have been described above, but for samples No. 2 to 81, the compositions of the basic components and additive components, their ratios, and the firing temperature in a reducing atmosphere were also determined. A multilayer ceramic capacitor was prepared in exactly the same manner as for sample No. 1, except for the changes shown in Tables 1 and 2, and its electrical characteristics were measured in the same manner.

Table 1 shows the composition of the basic components and additive components of each sample, and Table 2 shows the firing temperature and electrical characteristics of each sample.

Note that x and z in the basic component column of Table 1 are the number of atoms of each element in the composition formula (1) of the basic component described above, that is, (
The ratio of the number of atoms of each element is shown when the number of atoms of Ti+R) is 1.

In addition, Mg * Z n in the X column indicates the content of M in the basic component composition formula (1) described above, and Sc, Y,
Gd, Dy, Ho, Er, and Yb indicate the content of R in the above-mentioned basic component compositional formula (1).

These columns show the number of these atoms, and the total column shows the total value of Mg and Zn.

The amount of the additive component added is shown in parts by weight based on 100 parts by weight of the basic component. In the MO content column of the additive component, Ba
d, the proportion of MgO, ZnO, SrO and CaO is mol%
It is shown in

In Table 2, the temperature characteristics of capacitance are expressed as ΔC-5S (%) and ΔC,,, (%) for the capacitance change rate at −55°C and +125°C based on the capacitance at 25°C. So, 20
The rate of change in capacitance at −25° C. and +85° C. based on the capacitance at °C is shown as ΔC, . . . (%) and ΔC8, (%).

Table 2 (1) *Marked sample N and seven bites Table 2 (2) *Marked r vs. Table 2 (3) Table 2 (4) As is clear from Tables 1 and 2, the samples marked with * are sintered at temperatures below 1200°C in a non-oxidizing atmosphere. The dielectric constant ε1 is 3000 or more, and the tan δ is 2.
5% or less, resistivity ρ is lXl0'MΩ・cm or more, temperature change rate of capacitance ΔC-5, and 8C1□5 is 115%
~ +15%, ΔC-25 and ΔCss -10% ~ +1
0% range, making it possible to obtain a ceramic capacitor with desired characteristics.

On the other hand, sample No. 11-13, 26.31°32.
40~45.49.50,55,56゜62.63,6
9,80.81 cannot achieve the purpose of the present invention. Therefore, these are outside the scope of the present invention.

Table 2 shows the temperature change rate of capacitance ΔC-151! +8C
Although only 12Sl ΔC-ts+ ΔCss is shown, the temperature change rate ΔC of various capacitances in the range of 25°C to +85°C is -10% to +85°C for samples belonging to the scope of the present invention.
Within the range of +10%, and -55℃ to +125℃
The rate of change of various capacitances ΔC ranges from -15% to +
It is within the 15% range.

Next, the reasons for limiting the composition range of the dielectric ceramic composition of the present invention will be described.

First, when the value of X is zero as shown in sample No. 32, the temperature change rate ΔC-55 of capacitance is -
Although it is outside the range of +15%, as shown in sample No. 33.34, when the value of X is 0.01, desired electrical characteristics can be obtained. Therefore, the lower limit of X is 0.01.

On the other hand, as shown in sample Nos. 40 to 44, the value of X is 0.
．． In the case of Sample No. 38.12, the temperature change rate ΔC85 of capacitance is outside the range of -10% to +10%.
As shown in 39, when the value of X is 0.10, desired electrical characteristics can be obtained. Therefore, the upper limit of X is 0-10.

In addition, Mg and Zn, which are M components, act in the same way as f, and 0.
Desired electrical characteristics can be obtained by using one or both of Mg and Zn within a range that satisfies O1≦x≦o and io.

When the value of k is 0.98, as shown in sample No. 45, ρ becomes significantly lower than l
Although ΔCal is significantly worse than -15% and -io%, respectively, as shown in sample No. 46, when the value of k is 1.00, desired electrical characteristics can be obtained.

Therefore, the lower limit of the value of k is 1. It is OO.

On the other hand, the value of k is 1.0 as shown in sample No. 49.
In the case of sample No. 7, a dense sintered body cannot be obtained, but in the case of sample No.
As shown in 48, when the value of k is 1.05, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of k is 1.0
It is 5.

As the value of Z is shown in sample No. 50.56.63,
In the case of O, the temperature change rate of capacitance ΔC-6 @ Δ and 28 is -15%, respectively.

Although it does not satisfy within 10%, the value of Z is 0.00 as shown in sample No. 51.57.64.
In case 2, desired electrical characteristics can be obtained. Therefore 2
The lower limit of is 0.002.

On the other hand, the value of Z is sample No.-55, 62, 69°80.8
As shown in Sample No. 1, a dense sintered body cannot be obtained even if fired at 1250° C. in the case of 0.07, but sample No. 54.
As shown in 61.68 and 78.79, when the value is 0.06, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of Z is 0.06.

Note that the R components are Sc, Y, Gd, Dy, and Ho.

Er and Yb work in the same way as f, and the same result can be obtained even if one selected from them is used or a plurality of them are used in combination.

In any case where there is one type of R component or multiple types of R components, it is desirable that the value of Z is in the range of 0.002 to 0.06.

Note that the component represented by R in the compositional formula contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, it is possible to easily keep the temperature change rate of capacitance ΔC-55 to ΔC125 in the range of -15% to +15% in the range of -55°C to 125°C; ℃〜
Temperature change rate of capacitance ΔC-2, ~Δ in the range of 85℃
CIls can be easily kept within the range of -10% to +10%, and the fluctuation range of the temperature change rate of capacitance in each temperature range can be reduced.

Moreover, the R component has the effect of increasing the resistivity ρ and the effect of increasing the sinterability.

In addition, when the amount of additive components added is zero, sample No. 2
As is clear from No. 6, even if the firing temperature is 1250°C, a dense sintered body cannot be obtained. However, as shown in sample No. 27, the addition amount is 0.00% per 100 parts by weight of the basic components.
In the case of 2 parts by weight, desired electrical properties can be obtained by firing at 1190°C. Therefore, the lower limit of the additive component is 0.2 part by weight.

On the other hand, as shown in sample No. 31, when the amount of the additive component is 7.0 parts by weight, the dielectric constant ε is less than 3000, and the temperature change rate ΔC-55 of capacitance is Although it is outside the range of -15% to +15%, as shown in sample No. 30, when the amount added is 5.0 parts by weight, desired electrical characteristics can be obtained. Therefore, the upper limit of the amount added is 5.0 parts by weight.

The preferred composition of the additive components is B20°-510 in Figure 2.
It can be determined based on a triangular diagram showing the composition ratio of 2-Mo.

The first point A of the diagonal diagram indicates the composition of sample No. 1 with 1 mol% B2O3, 80 mol% Sin, and 19 mol% MO, and the second point B indicates the composition of sample No. 2. B2O3 of sample No. 3 is 1 mol%, 5in2 is 39 mol%, MO is 60 mol%, and the third point C is that B2O3 of sample No. 3 is 29 mol%
mol%, B2O3 is 1 mol%, MO is 70 mol%, and the fourth mark is 820 of sample No, , 4.
shows a composition of 90 mol%, B2O3 is 1 mol%, and MO is 9 mol%, and the fifth point E is sample No. 5, which has a composition of 90 mol% B2O3, 9 mol% SiO2, and 1 mol% MO. The sixth point F is sample No. 6, B, 03 is 1
The composition is 9 mol %, 80 mol % of Sin, and 1 mol % of MO.

The composition of the additive components of the sample that falls within the scope of the present invention is within the region surrounded by six straight lines connecting points 1 to 60 A-F of the triangular diagram in this order. If the composition is within this range, desired electrical characteristics can be obtained.

On the other hand, if the composition of the additive components falls outside the range specified in the present invention, as in Samples Nos. 11 to 13, a dense sintered body cannot be obtained.

In addition, MO acid components such as BaO, MgO, and ZnO as shown in Sample Nos. 14 to 18.

It may be either one of SrO or CaO, or it may be in an appropriate ratio as shown in other samples.

[Effect of the invention] According to the invention, since the composition of the dielectric ceramic composition is as described above, the dielectric constant is 3000 or more and the dielectric loss t is
anδ is 2.5% or less, resistivity p is lX10'MΩ・c
m or more, and the temperature change rate of the relative permittivity is -55°C
15% to +15% at ~125°C (based on 25°C, -2
It is possible to provide a ceramic capacitor including a dielectric ceramic composition that falls within the range of -10% to +10% (based on 20°C) at 5°C to 85°C.

Further, according to the present invention, in a non-oxidizing atmosphere, 12
Since it can be obtained by firing at a temperature of 00°C or less, it is possible to manufacture a ceramic capacitor by applying a conductive paste of a base metal such as nickel to a green sheet and firing the green sheet and the conductive paste at the same time. can.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a multilayer ceramic capacitor according to an embodiment of the present invention, and FIG. 2 is a triangular diagram showing the composition range of additive components. 12--Porcelain layer, 14--Internal electrode, 16---External electrode.

Claims (1)

[Claims] 1. A ceramic capacitor comprising a dielectric ceramic layer made of a dielectric ceramic composition and at least two or more internal electrodes sandwiching the dielectric ceramic layer, wherein the dielectric ceramic composition contains 100 parts by weight of the basic ingredients and
It is made by firing a mixture with 0.2 to 5 parts by weight of additional components, and the basic component is (Ba_k_-_xM_x)O_k(Ti_1_-_z
R_z) O_2_-_Z_/_2 (where M is Mg and/or Zn, R is one or more metal elements selected from Sc, Y, Gd, Dy, Ho, Er and Yb,
k, x, z are made of substances expressed by numerical values satisfying 1.00≦k≦1.05, 0.01≦x≦0.10, 0.002≦z≦0.06, and the additive component is B_2O_3 , SiO_2, and MO (where MO is one or more metal oxides selected from BaO, SrO, CaO, MgO, and ZnO), and the composition range of the B_2O_3, the SiO_2, and the MO is , in a triangular diagram showing these compositions in mol%, a first point A indicating a composition of 1 mol% of the B_2O_3, 80 mol% of the SiO_2, and 19 mol% of the MO; and 1 mol% of the B_2O_3. , a second point B having a composition of 39 mol% of the SiO_2 and 60 mol% of the MO; and a second point B having a composition of 29 mol% of the B_2O_3, 1 mol% of the SiO_2, and 70 mol% of the MO. 3 point C, and a fourth point D showing a composition of 90 mol% of B_2O_3, 1 mol% of SiO_2, and 9 mol% of MO; and 90 mol% of B_2O_3 and 9 mol% of SiO_2. , a fifth point E in which the MO has a composition of 1 mol %, the B_2O_3 is 19 mol %, and the SiO_2 is 80 mol %.
mol %, and the MO is located within a region surrounded by six straight lines connecting in this order a sixth point F showing a composition of 1 mol %. 2. A step of preparing a mixture made of unsintered porcelain powder, a step of forming an unsintered porcelain sheet made of the mixture, and a lamination in which the unsintered porcelain sheet is sandwiched between at least two or more conductive paste films. forming a product, firing the laminate in a non-oxidizing atmosphere, and heat-treating the fired laminate in an oxidizing atmosphere, from the unsintered porcelain powder. The mixture consists of 100 parts by weight of the basic component and 0.2 to 5 parts by weight of additional components, and the basic component is (Ba_k_-_xM_x)O_k(Ti_1_-_z
R_z) O_2_-_z_/_2 (where M is Mg and/or Zn, R is one or more metal elements selected from Sc, Y, Gd, Dy, Ho, Er and Yb,
k, x, z are made of substances expressed by numerical values satisfying 1.00≦k≦1.05, 0.01≦x≦0.10, 0.002≦z≦0.06, and the additive component is B_2O_3 , SiO_2, and MO (where MO is one or more metal oxides selected from BaO, SrO, CaO, MgO, and ZnO), and the composition range of the B_2O_3, the SiO_2, and the MO is , in a triangular diagram showing these compositions in mol%, a first point A indicating a composition of 1 mol% of the B_2O_3, 80 mol% of the SiO_2, and 19 mol% of the MO; and 1 mol% of the B_2O_3. , a second point B having a composition of 39 mol% of the SiO_2 and 60 mol% of the MO; and a second point B having a composition of 29 mol% of the B_2O_3, 1 mol% of the SiO_2, and 70 mol% of the MO. 3 point C, and a fourth point D showing a composition of 90 mol% of B_2O_3, 1 mol% of SiO_2, and 9 mol% of MO; and 90 mol% of B_2O_3 and 9 mol% of SiO_2. , a fifth point E in which the MO has a composition of 1 mol %, the B_2O_3 is 19 mol %, and the SiO_2 is 80 mol %.
A method for manufacturing a ceramic capacitor, characterized in that the MO is located within an area surrounded by six straight lines connecting in this order to a sixth point F showing a composition of 1 mol %.