JPH03278417A - Porcelain capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve relative permittivity by mixing 100 pts.wt. of specific basic component, and 0.01-3 and 0.2-5 pts.wt. of specific additive components of specific ranges 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, 0.01-3 pts.wt. of additive component containing Cr2O3 and/or AlO3 and 0.2-5 pts.wt. of additive component containing B2O3, SiO2 and MO (MO is metal oxide of one or more types selected from BaO, SrO, CaO, MgO and ZnO) are mixed and fired. 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 dielectric porcelain composition having 3000 or more of its relative permittivity can be formed. In formula I, M; Mg and/or Zn, L; Ca and/or Sr, R; one or more types or metal elements selected from Sc, Y, Gd, Dy, Ho, Er, Yb. Letters k, x, y, z; numerical values for satisfying formulae II, III, IV, V, VI.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ceramic capacitor having a single-layer or laminated structure in which a dielectric ceramic layer is sandwiched between two or more internal electrodes, and a method for manufacturing the same. It is.

[Prior Art] Conventionally, when manufacturing multilayer ceramic 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. A plurality of these sheets were stacked and pressed together, and fired at 1300°C to 1600°C in an oxidizing atmosphere.

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 precious metals such as platinum and palladium are expensive, the cost of multilayer ceramic capacitors has inevitably increased.

As a solution to the above-mentioned problem, Japanese Patent Publication No. 1983-1.4607, filed by the applicant, states (
A dielectric ceramic composition is disclosed that includes a basic component consisting of B a *-M There is.

In addition, Japanese Patent Publication No. 61-14608 discloses that the dielectric ceramic composition described in Japanese Patent Publication No. 61-14607 is
Instead of i, O and Sin, L i x O, S i
02 and MO (however, MO is BaO, CaO and Sr
A dielectric ceramic composition is disclosed that includes an additive component consisting of one or more metal oxides selected from O.

In addition, in Japanese Patent Publication No. 14609/1983, (B al
l-, -y M, L, 10. T i O, (However,
A dielectric ceramic composition is disclosed that includes a basic component consisting of M for Mg and/or Zn, and L for Sr and/or Ca, and additive components consisting of L i t O and SiO□.

Furthermore, in Japanese Patent Publication No. 61-14610, Lix
O, 5iOa and MO (however, MO is BaO, CaO
A dielectric ceramic composition is disclosed that includes an additive component consisting of one or more metal oxides selected from SrO and SrO.

In addition, in Japanese Patent Publication No. 14611/1983, (B a
k-M-)O-T 1.02 (However, M is Mg.

one or more metal elements selected from Zn, Sr and Ca), and B2O3 and SiO
A dielectric ceramic composition containing an additive component consisting of □ is disclosed.

In addition, in Japanese Patent Publication No. 1595/1983, (Bak-
x Mll) Oll T 102 (However, M is Mg
.

One or more metal elements selected from Zn, Sr, and Ca), and B2O3 and MO (
However, MO is Bao.

A dielectric ceramic composition containing an additive component consisting of one or more metal oxides selected from M g O, Z n O, S r O, and CaO is disclosed.

Furthermore, Japanese Patent Publication No. 62-1596 discloses that the B2O of the dielectric ceramic composition described in the above-mentioned Japanese Patent Publication No.
3 and B2O3 instead of MO.

5iO- and MO (however, MO is Bao.

A dielectric ceramic composition containing an additive component consisting of one or more metal oxides selected from M g O, Z n O, S r O, 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 very strong demand for miniaturization of ceramic capacitors, and it has been desired to develop a ceramic capacitor equipped with a dielectric ceramic composition having a higher dielectric constant than the dielectric ceramic compositions disclosed in the above-mentioned publications. .

In addition, since ceramic capacitors are used in various environments, they are equipped with a dielectric ceramic composition that has a smaller rate of change in relative dielectric constant over a wider temperature range than the dielectric ceramic compositions disclosed in the above-mentioned publications. There was a desire to develop a ceramic capacitor that would

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
The object of the present invention is to provide a ceramic capacitor equipped with 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 internal electrodes sandwiching the dielectric ceramic layer. The dielectric ceramic composition comprises 100 parts by weight of the basic component and 2O301 to 3 parts by weight of additive components l and 2O
It is made by firing a mixture with 32 to 5 parts by weight of additive component 2, and the basic component is (Bak-(x+y)MxLy)Ok(Ti1-y+)
l++LylOm (Tx+-zRz/2 (However, M is Mg and/or Zn, L is Ca and/or Sr, R is S
c, Y, Gd, Dy.

One or more metal elements selected from Ho, Er and Yb, k, x, y, z are 1.00≦k≦1.05 0<x<0.1.0 o<y≦0 .05 0.01≦z+y≦0.10 0.002≦z,so,06), and the additive component 1 is Crx 03 and/or A1. O, the additive component 2 consists of B 20 s, Stow, and MO (where MO is one or more metal oxides selected from BaO, SrO, CaO, MgO, and ZnO), The composition ranges of the B2O3, the SiO□, and the MO are shown in a triangular diagram showing these compositions in mol%.

A first point A having a composition of 1 mol% of the B2O3, 80 mol% of the SiO2, and 19 mol% of the MO; A second point B having a composition of 60 mol% of the MO, 29 mol% of the B201 and 1 mol% of the SiOt.
, a third point C having a composition of 70 mol% of the MO, and a fourth point having a composition of 90 mol% of the BtO, 1 mol% of the SiOz, and 9 mol% of the MO. rito, the B2O3 is 90 mol%, the 3i0z is 9 mol%,
A fifth point E in which the MO has a composition of 1 mol%, the B2O3 has a composition of 19 mol%, and the Sing has a composition of 80 mol%.
, within a region surrounded by six straight lines connecting in this order the sixth point F where the MO has a composition of 1 mol %.

Here, the value of k is preferably in the range of i, oo≦k≦1.05. When the value of k is 1200, the resistivity ρ is lX10
'MΩ・CII+, the temperature change rate of capacitance ΔC-65+ΔC325 deviates from -15% to +15%, ΔC-25ΔCss deviates from -10% to +], O%, and the value of k becomes 1. If it exceeds .05, it will not be possible to obtain a fine sintered body, but if the value of k is 1.OO≦k≦1.
This is because within the range of 0.05, a dense sintered body having desired electrical properties can be obtained.

Moreover, the value of x+y is preferably in the range of 0.01≦x+y≦0.10. When the value of x+y is less than 0.01, the temperature change rate Δc-55 of capacitance deviates from -15% to +15%,
If the value of x+y exceeds 0.10, the temperature change rate ΔC0 of capacitance will deviate from -10% to +lO%, but x
This is because when the value of +y is in the range of 0.01≦x+ys0.10, a product having desired electrical characteristics can be obtained.

However, even if c+y≦0.10, y≦0.05 is preferable. ) (Even if +y≦0.10 is satisfied, if the value of y exceeds 0.05, the temperature change rate of capacitance ΔC□
This is because the value will deviate from -10% to +10%.

In addition, Mg and Zn of the M component and Ca and Sr of the L component work in the same way as f, and Mg and Zn in the range satisfying 0<x<0.10
and Zn or both, and o
One or both of Ca and Sr can be used within a range that satisfies <y≦0.05.

Moreover, the value of Z is preferably in the range of 2O3002≦z≦0.06. When the value of 2 is less than 04002, the capacitance temperature change rate ΔC-5s deviates from -15% to +15%, and ΔC-
2% deviates from -10% to +10%, and if the value of Z exceeds 0106, a dense sintered body cannot be obtained, but in the range of 2O3002≦z≦0.06, the desired electrical characteristics can be obtained. This is because a dense sintered body having .

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

Er and Yb work in the same way as f, and the same effect can be obtained even if one selected from them is used or a plurality of them are used in combination. Therefore, the value of Z is desirably within the range of 0.002≦2≦0.06, regardless of whether there is one type of R component or multiple types of R components.

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-88 in the range of ~125°C
~8C12+1 can be easily kept in the range of -15% to +15%, and the temperature change rate of capacitance ΔC-as ~80 in the range of -25°C to 85°C, s is -10
It becomes possible to easily keep it within the range of % to +10%,
Moreover, it is possible 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.

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

In addition, a trace amount of M n O□ (preferably 0.05 to 0.1
% 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 BaO and SrO.

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

Next, the amount of additive component 1 added is preferably in the range of 0101 to 3 parts by weight per 100 parts by weight of the basic component.
If it is less than 01, the capacitance temperature change rate ΔC-5s will be outside the range of -15% to +15%, and if it exceeds 3.0 parts by weight, it will not be a dense sintered body even if fired at 1250°C. However, when the additive component 1 is in the range of 0.01 to 3 parts by weight, a sintered body with desired characteristics can be obtained.

In addition, CrtOs of additive component 1 and A1. O, works in the same way as f, and the same result can be obtained even if one selected from them or a plurality of them are used. In any case where the number of additive components 1 is one or more, the amount added is preferably in the range of 0.01 to 3.0.

Note that this additive component 1 contributes to improving the temperature characteristics of capacitance. That is, by adding the additive component 1, the temperature change rate of capacitance Δc-8% to ΔC125 is changed from 15% to +15.
It is possible to keep the capacitance temperature change rate ΔC-26 to ΔCas within the range of -10% to +10%.
It becomes possible to easily keep the capacitance within the range of , and it is possible to reduce the fluctuation width of the temperature change rate of capacitance in each temperature range. Further, the additive component 1 has the effect of slightly increasing the resistivity ρ.

Next, the amount of additive component 2 added is preferably in the range of 2 to 5 parts by weight per 100 parts by weight of the basic component. If the amount of additive component 2 is less than 0.2 parts by weight, a dense sintered body cannot be obtained even if the firing temperature is 1250°C, and
When the amount of additive component 2 exceeds 5 parts by weight, the dielectric constant ε
8 is less than 3000, and the capacitance temperature change rate ΔC-15 is outside the range of -15% to +15%, but if additive component 2 is in the range of 0.2 to 5 parts by weight, the desired electrical This is because characteristic properties can be obtained.

The composition of additive component 2 is B x Os Si O -
Points 1 to 6 A- of the triangular diagram showing the composition ratio of MO in mol%
Preferably, it is within the area surrounded by six straight lines connecting F in order.
If the composition of additive component 2 is outside this range, a dense sintered body cannot be obtained, but if the composition is within this range,
This is because a sintered body with desired electrical characteristics can be obtained.

Note that the starting material for additive component 2 may be other compounds such as oxides and hydroxides.

Next, 1. 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-mentioned basic components, additive component 1, and additive component 2; a step of forming a porcelain sheet; a step of forming a laminate in which the unsintered porcelain sheet is sandwiched between at least two conductive paste films; and a step of firing the laminate in a non-oxidizing atmosphere; and a step of heat-treating the fired 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 600°C in the example, it is not limited to this, and may be any temperature lower than the sintering temperature, preferably 500°C to 1.5°C. A range of OO0°C is preferable.

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 sample No. 1 in Table 1 and its electrical characteristics will be explained.

Each compound of Formulation 1 was weighed and mixed for 15 hours to obtain a raw material mixture.

Here, the weight of the compound of formulation 1 (g) and mole part is the general formula of the basic components %formula% This is the value calculated so that.

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.

Preparation of Additive Acid 2 Also, the compounds of Formulation 2 were each weighed and mixed, 300 cc of alcohol was added to this mixture, and after stirring for 10 hours using an alumina ball in a polyethylene pot, the mixture was heated to a temperature of 1000'C in the air. It was pre-baked for 2 hours.

Here, the weight (g) and molar parts of the compound of formulation 2 are B2
O3 is 1 mol%, SiO□ is 80 mol%, MO is 19 mol% (BaO (3.8 mol%) + CaO (3.8 mol%)
) + SrO (3,8 mol%) + MgO (3,8 mol%)
+ZnO (3.8 mol %)).

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 component 2 was obtained.

Incidentally, the contents of MO are BaO and CaO.

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

L1 Any Stand] 1 Next, 2 parts by weight (20 g) of the additive component 2 was added to 100 parts by weight (1000 g) of the basic component, and further, the particles were well-aligned with an average particle size of 0.5 μm. Purity 99.
0.1 parts by weight (1 g) of 0% or more Crz Ox was added as additive component 1, and an organic binder consisting of an aqueous solution of acrylic acid ester polymer glycerin and condensed phosphate was added to the basic component and additive component 1.2. Added 15% by weight based on the total weight of and further added 50% by weight of water,
These were placed in a ball mill, pulverized and mixed to prepare a slurry of porcelain raw materials.

Next, the above slurry is placed in a vacuum defoaming machine to degas it, this slurry is placed in a reverse roll coater, and the thin film molding obtained from this is coated 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 and is used by cutting it into 10 cm squares.

Preparation of conductive paste On the other hand, conductive paste for internal electrodes has an average particle size of 1-.
10 g of 5 μm nickel powder and 0.0 g of ethyl cellulose.
A solution of 9.1 g of butylcarpitol 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.

Layer of unsintered porcelain sheets Next, two unsintered porcelain 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.

Pressing and cutting the waste material.Then, this laminate is cut in the thickness direction at a temperature of about 50°C.
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.

Layer Chip Firing Next, this laminate chip was placed in a furnace capable of atmosphere firing, and heated to 600°C at a rate of 100°C/h in an air atmosphere.
The organic binder was burned by increasing the temperature to .

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.

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 lO 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 a mixture of the basic components and additive components before sintering. The composition is substantially the same.

The electrical characteristics of the multilayer ceramic capacitor 10 are measured after the electric current is constant.
When the average value was calculated, as shown in Table 2, the relative permittivity ε8 was 3700, the tan δ was 1.1%, the resistivity ρ was 4.6X10'MΩ'cm, and the capacitance at 25°C was used as the standard. The rate of change in capacitance at -55°C and +125°C ΔC-
55ΔC128 is -10.3%, +5.5%, capacitance change rate ΔC-□ at -25°C and +85°C based on capacitance at 20°C, Css is -5.9%.

-4.4%.

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

The relative permittivity of fAl is ε at a temperature of 20°C and a frequency of 1kHz.
The capacitance was measured under the conditions of voltage (effective value) i, ov, and this measured value was compared with the opposing area of the pair of internal electrodes 14 of 25 mm.
and the thickness O of the dielectric ceramic layer 12 between the pair of internal electrodes 14
It was calculated from y02mm.

fB) Dielectric loss tan δ (%) was measured under the same conditions as the above measurement of relative dielectric constant.

The tel resistivity ρ (MΩ・cm) is determined by applying DClooV for 1 minute at a temperature of 20° C.
The resistance value between them was measured and calculated based on this measured value and the dimensions.

The temperature characteristics of fDl capacitance are as follows: -55°C, -25°C, 0°C, +20°C when the sample is placed in a constant temperature bath.

+25℃, +40℃, +60℃, +85℃.

Frequency 1 at each temperature of +105℃ and +125℃
The capacitance was measured under the conditions of kHz, voltage (effective value) L, and OV, and the rate of change at each temperature with respect to the capacitance at 20° C. and 25° C. was obtained.

The method for preparing samples No. 1 and their characteristics have been described above, but the compositions of the basic components and additive components 1 and 2, their ratios, and the firing temperature in a reducing atmosphere have also been described for samples No. 102 to 105. Except for the changes shown in Tables 1 and 2, multilayer ceramic capacitors were prepared in exactly the same manner as for samples No. 1 and their electrical characteristics were measured in the same manner.

Table 1 shows the composition of the basic components and additive components 1.2 of each sample, and Table 2 shows the firing temperature and electrical characteristics of each sample.

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

Furthermore, Mg and Zn in the X column indicate the contents of M in the basic component composition formula (1), and Ca and Sr in the y column indicate the contents of the basic component composition formula (1). Sc in the Z column
, Y, Gd, Dy.

Ho, Er, and Yb are represented by the above-mentioned basic component composition formula (1
) shows the contents of R.

These columns show the number of these atoms, and the total column shows the total value (x+y) of Mg, Zn, Ca, and Sr.

The amounts of additive components 1 and 2 are shown in parts by weight based on 100 parts by weight of the basic component. The MO content column for additive component 2 contains B a O, M g O, and Z n O.

The proportions of SrO and CaO are shown in mol%.

In Table 2, the temperature characteristics of capacitance are as follows: △C,,, (%) and ΔC4□ (%) So, 20
The capacitance change rates at -25°C and +85°C based on the capacitance at °C are shown as Δ(,,,(%)) and ΔC05(%).

Table 2 (1,) ※marked fmM seven examples Table 2 (2) ※marked n) makura dshi examples Table 2 (3) ※marked samples Comparative example Table 2 (4) *The R-ka-sudashita-furi shout is the old jQ column Table 2 (5) *It is clear from the marked Shitatsu Shichima-Rio Copper column Tables 1 and 2 As shown, in the sample according to the present invention, when fired at 1200°C or less in a non-oxidizing atmosphere, the relative dielectric constant ε.

is 3000 or more, tan δ is 2.5% or less, resistivity ρ is 1xlO'MΩ・cm or more, temperature change rate of capacitance ΔC
-i, and ΔC+zs is 115% to +15%, 8C-2
8 and ΔCas are in the range of -10% to +10%, making it possible to obtain a ceramic capacitor with desired characteristics.

On the other hand, sample No. 11-13.26, 31°32.40
~44,50,54,55,60°61.67.68.
74.85.86,87°96~98,104,105
In this case, the object of the present invention cannot be achieved. Therefore,
These are outside the scope of the present invention.

Table 2 shows the temperature change rate of capacitance ΔC-0゜8C11S
o ΔC−2s + ΔCas only is shown, but
The temperature change rate ΔC of various capacitances in the range of 25°C to +85°C of samples belonging to the scope of the present invention is -10% to +l
0%, and the various capacitance change rates ΔC in the range of -55°C to +125°C are -15% to +15°C.
% 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+y is zero as shown in sample No. 32, the temperature change rate of capacitance ΔC~55 is 15
Although it is outside the range of % to +15%, sample No. 33 to 35
As shown in the figure, when the value of X+y is 0.01, desired electrical characteristics can be obtained. Therefore, the lower limit of x+y is 0.
It is 01.

On the other hand, as shown in sample Nos. 41 to 43, when the value of x+y is 0.12, the temperature change rate ΔC□ of capacitance is outside the range of -10% to +10%, but sample No. , 39
．． As shown in 49, when the value of x+y is 0.10, desired electrical characteristics can be obtained.

However, as shown in sample No. 40.44, even if the value of y, +y is 0.10, if the value of y exceeds 0.05, △C'ms becomes = 10~ Since this is outside the range of +10%, the upper limit of x+y is 0.10, but at the same time the upper limit of y must be 0.05.

In addition, Mg and Zn of the M component and Ca and Sr of the L component work in the same way as A, and Mg
and Zn or both, and o
One or both of Ca and Sr can be used within a range that satisfies <y≦0.05. It is desirable that the value of x+y be in the range of 0.01 to 0.10 in either case of one or more of the M component and the L component.

When the value of k is 0.98 as shown in sample No. 50, tan δ is thicker than 2.5% (and ρ is lX
It is significantly lower than 10'MΩ-cflI, and the temperature change rate of capacitance ΔC-+i%@ΔC-21i is also =
15%, which is significantly worse than -10%, but sample N
o, 51, if the value of k is 1.00,
Desired electrical characteristics can be obtained. Therefore, the lower limit of the value of k is 1.00.

On the other hand, the value of k is 1.0 as shown in sample No. 54.
In the case of sample No. 7, a dense sintered body cannot be obtained, but in the case of sample No.
As shown in 53, 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. 55.61.68,
In the case of zero, the capacitance temperature change No. 8 C-11m + No. 8 C-1s does not satisfy within -15% and -10%, respectively, but as shown in sample No. 56.62.69, Z
When the value of is 0.002, desired electrical characteristics can be obtained. Therefore, the lower limit of Z is 0.002.

On the other hand, the value of 2 is sample No. 60.67.74°85.8
As shown in Sample No. 6, in the case of 2O307, a dense sintered body could not be obtained even if fired at 1250°C.
As shown in 66.73 and 83.84, 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 Er and Yb, 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 becomes possible to easily keep the temperature change rate of capacitance ΔC-55 to ΔCIts in the range of -15% to +15% in the range of -55°C to 125°C. ℃～
It becomes possible to easily keep the temperature change rate of capacitance ΔC-25 to 8Ca@ in the range of -10% to +10% in the range of 85°C, and the temperature change of capacitance in each temperature range. It is possible to reduce the fluctuation range of the rate.

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

C r z O□ and/or A1□0 which is additive component 1
If the addition amount of 3 is zero as in sample No. 87.98, ΔC-5 will be less than 115%, but sample No.
As shown in 88.89.99.100, the amount added is 100
Desired properties can be obtained when the amount is 0.01 part by weight per part by weight of the basic component. Therefore, the lower limit of the additive component l is 0.01.

On the other hand, as shown in sample No. 96.97, 104, and 105, when the amount of additive component 1 added is more than 3.0 parts by weight, a dense sintered body cannot be obtained even if fired at 1250°C. However, as shown in sample Nos. 93 to 95.103, 3
．． In the case of 0 parts by weight, desired characteristics can be obtained.

Therefore, the upper limit of additive component 1 is 3.0 parts by weight.

Note that Crz Ox and A 1 *O-, which are additive components 1, work in the same manner 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 any case where the number of additive components 1 is one or more, the amount added is preferably in the range of 0.01 to 3.0.

Note that this additive component 1 contributes to improving the temperature characteristics of capacitance. That is, by adding additive component 1, the temperature
Temperature change rate of capacitance in the range of 125℃ △C-65~
It becomes possible to keep ΔCI□5 within the range of -15% to +1.5%, and the temperature change rate of capacitance ΔC-25 to 8Cas in the range of -25°C to 85°C can be kept within the range of -15% to +1.5%. %～
It becomes possible to easily keep the capacitance within the range of +10%, and it is possible to reduce the fluctuation range of the temperature change rate of capacitance in each temperature range. Further, the additive component 1 has the effect of slightly increasing the resistivity p.

In addition, when the amount of additive component 2 added is zero, sample No.
As is clear from Sample No. 26, 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.
．． In the case of 2 parts by weight, desired electrical properties can be obtained by firing at 1190°C. Therefore, the lower limit of additive component 2 is 0.2
Parts by weight.

On the other hand, as shown in sample No. 31, when the amount of additive component 2 is 7.0 parts by weight, the dielectric constant ε is 3000.
Furthermore, the temperature change rate ΔC-55 of capacitance is outside the range of -15% to +15%, but sample No. 30
As shown in the figure, 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.

A preferable composition of additive component 2 is Bz 03-S in FIG.
It can be determined based on a triangular diagram showing the composition ratio of iOx-MO.

The first point A of the triangular diagram indicates the composition of sample No. 1 with 1 mol% B2O3, 80 mol% 5iO-, and 19 mol% MO, and the second point B indicates the composition of sample No. 2. The composition was 1 mol% B2O3, 39 mol% S i Oz, and 60 mol% MO.

At the third point C, B2O3 of sample No. 3 is 29 mol%,
Sin shows a composition of 1 mol% and MO 70 mol%,
The fourth spot is sample No. 4 with 90 mol% B2O3 and S
It has a composition of 1 mol% iO2 and 9 mol% MO, and the fifth
Point E is sample No. 5 with 90 mol% B2O3 and 5i
The sixth point F has a composition of 9 mol% O- and 1 mol% MO, and the sixth point F is sample No. 6 with 19 mol% B20- and Si
The composition is 80 mol% O, and 1 mol% MO.

The composition of additive component 2 of the sample belonging to the scope of the present invention is within the region surrounded by six straight lines connecting points 1 to 6 of the triangular diagram in order. If the composition is within this range, desired electrical characteristics can be obtained.

On the other hand, if the composition of additive component 2 falls outside the range specified in the present invention, as in Samples Nos. 11 to 13, a dense sintered body cannot be obtained.

Incidentally, the MO acid components include, for example, 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.

[Effects of the Invention] According to the present 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 ρ is lX10'MΩ・c
m or more, and the temperature change rate of the relative permittivity is -55°C
-15% to +15% at ~125℃ (based on 25℃), -
-10% to +10% at 25℃ to 85℃ (based on 20℃)
It is possible to provide a ceramic capacitor with a dielectric ceramic composition falling within the range of .

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, a ceramic capacitor can be manufactured by applying a conductive paste of a base metal such as nickel to a green sheet and firing the green sheet and the quaternary conductive paste at the same time. I can do it.

[Brief explanation of drawings]

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 component 2. 12... Ceramic 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 consists of a mixture of 0.01 to 3 parts by weight of additive component 1 represented by Me_2O_3 and 0.2 to 5 parts by weight of additive component 2, and the basic component is (Ba_k_-_(_x_+_y_)M_xL_y )O
＿k(Ti_1_-_zR_z)O_2_-_z_/_
2 (However, M is Mg and/or Zn, L is Ca and/or Sr, R is Sc, Y, Gd, Dy, Ho, Er, and Y
one or more metal elements selected from b, k,
x, y, z satisfy 1.00≦k≦1.05 0<x<0.10 0<y≦0.05 0.01≦x+y≦0.10 0.002≦z≦0.06 The additive component 1 consists of Cr_2O_3 and/or Al_2O_3, and the additive component 2 consists of B_2O_3, SiO_2, and MO (however, MO is BaO, SrO, CaO, MgO, and ZnO).
one or more metal oxides selected from ), and the composition range of the B_2O_3, the SiO_2, and the MO is such that the B_2O_3 is 1 mol in the triangular diagram showing these compositions in mol%. %, a first point A having a composition of 80 mol% of the SiO_2 and 19 mol% of the MO, and a composition of 1 mol% of the B_2O_3, 39 mol% of the SiO_2, and 60 mol% of the MO. a second point B; a third point C having a composition of 29 mol% of B_2O_3, 1 mol% of SiO_2, and 70 mol% of MO; 90 mol% of B_2O_3 and 1 mol of SiO_2; %, a fourth point D having a composition of 9 mol% of the MO, and a fifth point E having a composition of 90 mol% of the B_2O_3, 9 mol% of the SiO_2, and 1 mol% of the MO; The B_2O_3 is 19 mol%, and the SiO_2 is 80% by mole.
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. A mixture consisting of 100 parts by weight of the basic component and 0.01 to 3 parts by weight of Me
It consists of an additive component 1 represented by _2O_3 and an additive component 2 of 0.2 to 5 parts by weight, and the basic component is (Ba_k_-_(_x_+_y_)M_xL_y)O
＿k(Ti_1_-_zR_z)O_2_-_z_/_
2 (However, M is Mg and/or Zn, L is Ca and/or Sr, R is Sc, Y, Gd, Dy, Ho, Er, and Y
one or more metal elements selected from b, k,
x, y, and z satisfy 1.00≦k≦1.05 0<x<0.10 0<y≦0.05 0.01≦x+y≦0.10 0.002≦z≦0.06 The additive component 1 consists of Cr_2O_3 and/or Al_2O_3, and the additive component 2 consists of B_2O_3, SiO_2, and MO (however, MO is BaO, SrO, CaO, MgO, and ZnO).
one or more metal oxides selected from ), and the composition range of the B_2O_3, the SiO_2, and the MO is such that the B_2O_3 is 1 mol in the triangular diagram showing these compositions in mol%. %, a first point A having a composition of 80 mol% of the SiO_2 and 19 mol% of the MO, and a composition of 1 mol% of the B_2O_3, 39 mol% of the SiO_2, and 60 mol% of the MO. a second point B; a third point C having a composition of 29 mol% of B_2O_3, 1 mol% of SiO_2, and 70 mol% of MO; 90 mol% of B_2O_3 and 1 mol of SiO_2; %, a fourth point D having a composition of 9 mol% of the MO, and a fifth point E having a composition of 90 mol% of the B_2O_3, 9 mol% of the SiO_2, and 1 mol% of the MO; The B_2O_3 is 19 mol%, and the SiO_2 is 80% by mole.
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 %.