JPH03278421A - Porcelain capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve relative permittivity by mixing 100 pts.wt. of specific basic component, 3.0 pts.wt. or less of first specific additive component, and 0.2-5 pts.wt. of second 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, 3.0 pts.wt. or less of first additive component containing Cr2O3 and/or AlO3 and 0.2-5 pts.wt. of second additive component containing B2O3, SiO2 and MO (MO is one or more types of metal oxide selected from BaO, SrO, CaO, MgO and ZnO) are mixed and fired. The composition range of the second additive compo nent 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 composi tion range of the second additive component, and hence its relative permittivity can be set to 3000 or more. 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, Tb, Tm, Lu. Letters alpha, k, x, z, y; numerical values for satisfying formulae II, III, IV, V, VI, VII.

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 at least two internal electrodes, and a method for manufacturing the same. .

[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 desired internal electrodes can be obtained even if fired at a high temperature of 1300°C to 1600°C in an oxidizing atmosphere. be able to.

However, since noble metals such as platinum and palladium are expensive, the cost of N-product porcelain capacitors has inevitably increased.

Japanese Patent Publication No. 14607/1983, filed by the applicant, discloses (B
a basic component consisting of a k-M , +ok T i O2 (where M is Mg and/or Zn), and L x 2
0 and an additive component consisting of SiO□.

In addition, Japanese Patent Publication No. 14608/1983 discloses that k, Lis
O, Sing and MO (However, MO is Bad, 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. 14609/1983, (Bak
- to -V Mll Ly+om T i 02 (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, izo, and Sin.

Furthermore, Japanese Patent Publication No. 61-14610 discloses that k, Li 2O3 instead of LizO and SiO□ in the dielectric ceramic composition described in Japanese Patent Publication No. 61-14609 mentioned above
A dielectric ceramic composition is disclosed that includes an additive component consisting of S i 02 and MO (where MO is one or more metal oxides selected from Bad, CaO, and SrO).

Furthermore, in Japanese Patent Publication No. 61-14611, (B al
l-x MXIClv T i 02 (However, M is Mg.

one or more metal elements selected from Zn, Sr and Ca), and B2O3 and 5i0
A dielectric ceramic composition is disclosed that includes an additive component consisting of:

In addition, in Japanese Patent Publication No. 1595/1983, (B all
-x M*] OkT i Ox (where 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.

In addition, Japanese Patent Publication No. 1596/1982 discloses 82O of the dielectric ceramic composition described in Japanese Patent Publication No. 1595/1982.
3 and k instead of MO, B2O3.

Sin, and MO (However, MO is Bad.

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 ±1 from -25°C to +85°C.
It can be set in the range of 0%.

[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 FFI capacitors are 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
1.Although it is obtained by firing at a temperature of 200℃ or less, the relative permittivity is 3000 or more and the dielectric loss t
anδ is 2.5% or less, resistivity ρ is I x 10'Ω・
cm or more, and the temperature change rate of relative permittivity is between 155℃ and 1
-15% to +15% at 25℃ (based on 25℃), -25
It is an object of the present invention to provide a ceramic capacitor equipped with a dielectric ceramic composition that falls within the range of -10% to +10% (based on 20°C) at a temperature of 85°C to 85°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. In the ceramic capacitor, the dielectric ceramic composition comprises 100 parts by weight of a basic component;
It is made by firing a mixture of 3.0 parts by weight or less of the first additive component and 0.2 to 5 parts by weight of the second additive component, and the basic component is (where M is Mg and/or Zn, L is Ca and/or Sr, R is Sc, Y, Gd, Dy.

1 selected from Ho, Er, Yb, Tb, Tm, Lu
species or two or more metals, α, k, x.

z, y are 0, 005 ≦a≦0.04 1. OO≦to≦1,05 0<x<0. 10 0<z≦0.05 0, 01 ≦X+Z ≦ 0, 1.

It consists of a substance represented by a number (a) satisfying o<y≦0.04, the first additive component consists of CrzOx and/or A1□O1, and the second additive component consists of B2O3, SiO2, and MO. (However, MO is one or more metal oxides selected from BaO, SrO, Cab, MgO, and ZnO).

The composition ranges of the B-Os, the SL Ot, and the MO are as follows: in the triangular diagram showing these compositions in mol%, the B2O3 is 1 mol%, the Sin is 80 mol%,
A first point A having a composition of 19 mol% of the MO; and a second point B having a composition of 1 mol% of the B2O3, 39 mol% of the SiOt, and 60 mol% of the MO; The B2O3 is 30 mol%, the SiO□ is 0 mol%,
A third point C having a composition of 70 mol% of the MO; and a fourth point C having a composition of 90 mol% of the B2O3, 0 mol% of the SiOz, and 10 mol% of the MO; The B2O3 is 90 mol%, and the SiO□ is 10 mol%.
, a fifth point E where the MO has a composition of 0 mol%, the B2O3 is 20 mol%, the B2O3 is 1 mol%,
It is located within a region surrounded by six straight lines connecting in this order the sixth point F showing a composition of 0 mol % MO.

Here, the reason why 0.005≦α≦0.04 is set is that α is 0.
．． A dielectric ceramic composition having desired electrical properties can be obtained in the range of 0.05≦α≦0.04, but when α is 0.
．． When it becomes less than 005, the temperature change rate of capacitance ΔC-2
5 outside the range of -10% to +10%, ΔC-@6 -15
% to +15% and when α exceeds 0.04, the capacitance temperature change rate ΔCaS will be -10% to +10%.
This is because it is outside the range of .

Also, the reason why 1.00≦≦1.05 is set is that k is 1. ．．
A dielectric ceramic composition having desired electrical properties can be obtained in the range of 00Sk≦1.05, but when k is 1.0
This is because when k is less than 0, the resistivity ρ becomes significantly lower than LX10'MΩ·cm, and when k exceeds 1.05, a dense sintered body cannot be obtained.

Also, the reason why 0,01≦X+Z≦0.10 is set is that X+Z
In the range of 0.01≦X+Z≦0.10, a dielectric ceramic composition with desired electrical properties can be obtained;
When becomes less than 0.01, the temperature change rate of capacitance ΔC-
2, outside the range of 110% to +10%, 8C-am is 11
If it is outside the range of 5% to +15% and x+z exceeds 0.10, the temperature change rate ΔCss of capacitance will be -10% to +10%.
This is because it is outside the 10% range.

However, even if X+Z is within the range of 0.01≦x+z≦0.10, if Z exceeds 0.05, a dielectric ceramic composition having desired electrical properties cannot be obtained. Therefore, the upper limit value of X+Z is 0.10, but at the same time, the upper limit value of 2 must be set to 0.05.

In addition, Mg and Zn of the M component and Ca and Sr of the L component are S.
One or both of Mg and Zn can be used within a range that works similarly and satisfies O<x<0.10, and O<z
One or both of Ca and Sr can be used within a range satisfying ≦0.05.

It is desirable that the value of X+Z 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.

Also, the reason why o<y≦0.04 is set is that y is o<y≦0.
If y is in the range of 0.04, a dielectric ceramic composition with desired electrical properties can be obtained, but if y exceeds 0.04, a dense sintered body cannot be obtained.

Then, the R components Sc, Y, Dy, and Ho.

Er, Yb work in the same way as S, and 1 selected from these
Similar results can be obtained using one or more. Regardless of whether there is one type of R component or multiple types of R components, it is desirable that the value of y be in the range of 0.04 or less. Further, if y is 0.04 or less, even a small amount close to 0 will have a certain effect.

In the composition formula, the component represented by R contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, the temperature
Temperature change rate of capacitance in the range of 25°C Δ and ss It becomes possible to easily keep Cl28 in the range of -15% to +1.5%, and k, in the range of -25°C to 85°C. Temperature change rate of capacitance in the range △C-2, ~ ΔC85 - 10
It becomes possible to easily keep it within the range of % to +10%,
In addition, the fluctuation width of the temperature change rate of capacitance in each temperature range can be reduced.

Further, 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 and z indicate the number of atoms of each element, and l-α and α are IBam-x-zMRLzlOi+ (T1+-yRs
t) The ratio of Ox-yyz to BaZr0a in the second term is shown in moles.

In addition, among the basic components, a trace amount of MnOz (preferably 0.05 to 0.1% by weight) is added within a range that does not impede the purpose of the present invention.
) 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 upper limit of the first additive component was set at 3.0 parts by weight.
When the amount of the first additive component added is 3.0 parts by weight, a dielectric ceramic composition having desired electrical properties can be obtained; however, when the amount exceeds 3.0 parts by weight, This is because a dense sintered body cannot be obtained even if fired at ℃.

Even if the first additive component is in an extremely small amount (0<first additive component) within the range of 3.0 parts by weight or less, it has a certain effect. However, in consideration of variations in electrical properties during mass production, it is desirable to add 0.001 part by weight or more.

Note that the first additive component CrtOs and A1. O.

works in the same way as f, and the same result can be obtained by using one selected from these, or by using a plurality of them.

Whether the first additive component is one type or multiple types, the amount added is desirably within a range of 3.0 parts by weight or less.

This first additive component contributes to improving the temperature characteristics of capacitance. That is, by adding the first additive component, the temperature of -55°C to 1
Temperature change rate of capacitance ΔC-1s to Δ in the range of 25℃
C325 can be easily kept in the range of -15% to +15%, and the temperature change rate of capacitance ΔC-1 to △C□ in the range of -25°C to 85°C can be reduced to -10%. ~+1
It becomes possible to easily keep the capacitance within the range of 0%, and it is possible to reduce the fluctuation width of the temperature change rate of capacitance in each temperature range.

Further, the first additive component has the effect of slightly increasing the resistivity p.

Next, the second additive component was set in the range of 0.2 to 5 parts by weight relative to 100 parts by weight of the basic component. A dielectric ceramic composition having electrical properties can be obtained, but if the second additive component is less than 0.2 parts by weight, the firing temperature will be 1250°C.
However, a dense sintered body cannot be obtained even if the second additive component is 5
When the weight part is exceeded, the relative permittivity ε8 becomes less than 3000, and the temperature change rate ΔCas of capacitance is -10% to +
This is because it is outside the 10% range.

The composition of the second additive component is B2O3, S i Oa, and MO
In the triangular diagram showing the composition in mol%, the first to
The reason why points A-F in No. 6 are placed in the area surrounded by six straight lines connecting them in order is that if the composition of the second additive component is within this area, the dielectric ceramic composition has the desired electrical characteristics. However, if the composition of the second additive component falls outside this range, a dense sintered body cannot be obtained.

Note that the MO acid components are Bad, MgO, and ZnO.

It may be either one of SrO or CaO, or it may be in an appropriate ratio. Further, the starting materials for the additive components may be other compounds such as oxides and hydroxides other than those shown in the examples.

Next, the method for manufacturing a ceramic capacitor according to the present invention includes the above basic components and the first method. a step of preparing a mixture of unsintered porcelain powder comprising a second additive component; a step of forming an unsintered porcelain sheet comprising the mixture; The method comprises a step of forming a laminate sandwiched between films, a step of firing the laminate in a non-oxidizing atmosphere, and a step of heat-treating the fired laminate in an oxidizing atmosphere. be.

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 H2 or GO, 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 single-layer ceramic capacitors other than multilayer ceramic capacitors.

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

[L-bond double bean paste] 1 The compounds of Formulation 1 were each weighed, and these compounds were added together with a pot mill (pot a + 1lllk, alumina balls and 2.5 g of water), and mixed with stirring for 15 hours to obtain a raw material mixture.

Formulation 1 Here, the weight (g) and molar parts of the compound in Formulation 1 are fBam-x-xMxLxloi+ (Tl+-yRy
lOz-yzz (hereinafter referred to as the first basic component) is (Baa, asMga, a2Zno, ozcaa
, o+sra, at)0+, ozfTi, o,
eeYbo, ol) 0, mis.

Next, put this raw material mixture into a stainless steel pot, dry it at 150°C for 4 hours using a hot air dryer, coarsely crush this dried raw material mixture, and use a tunnel furnace to crush this coarsely crushed raw material mixture. The powder was calcined for 2 hours at about 1200° C. to obtain a powder of the first basic component in the composition formula (1) of the above basic component.

In addition, BaZrOx in the second term of the basic component composition formula (1)
(hereinafter referred to as the second basic component), k, B
k so that a CO3 and Z r Ot are equimolar,
615.61 g of the former and 384.39 g of the latter were weighed, mixed, dried, pulverized, and then calcined in the atmosphere at about 1250° C. for 2 hours.

Then, as shown in Sample No. 1 in Table 1, k, 98 mol parts (976.28 g) of powder of the first basic component so that k, 1-0 is 0.98 mol, and a is 0.02 mol. and 2 mole parts (23.72 g) of powder of the second basic component were mixed to obtain 1000 g of the basic component.

Further, the compounds of Formulation 2 were each weighed and mixed, 300 cc of alcohol was added to this mixture, and the mixture was stirred for 10 hours using an alumina ball in a polyethylene pot.
Thereafter, it was calcined in the air at a temperature of 1000° C. for 2 hours.

Here, the weight (g) of the compound of formulation 2 is B2O3 1
mol%, SiO2 80 mol%, MO 19 mol% (B
aO (3,8 mol % l + Ca0 (9,5 mol % l + M
go (5.7 mol %)).

Next, put the material obtained by the above calcination into an alumina pot with 300cc of water, and use an alumina ball to
The powder was pulverized for hours and then dried at 150° C. for 4 hours to obtain a powder of the second additive component.

Note that the proportions of Bad, CaO, and MgO, which are the contents of MO, are k, 20 mol%, 50 mol%, and 30 mol%, as shown in Table 1.

After preparing the slurry, 100 parts by weight (looOg) of the basic component k,
As the first additive component, the average particle size should be 0.5 μm (Cr2O3 and A 1 x O with uniform grains and purity of 99.0% or more).
z and 0.1 part by weight (1 g), and 2 parts by weight (20 g) of the second additive component, and further k, acrylic acid ester polymer glycerin, and a water droplet liquid of condensed phosphate. Adding an organic binder in an amount of 15% by weight based on the total weight of the basic component and the first and second additive components,
Further, 50% by weight of water was added, and the mixture was placed in a ball mill to be ground and mixed to prepare a slurry of porcelain raw materials.

Formation of an unmagnetized sheet Next, the above slurry is degassed by putting it into a vacuum defoaming machine, and this slurry is put into a reverse roll coater, and the thin film molding obtained from this is continuously coated on a long polyester film. I let him take it, and on the same film I gave him 100.
It was dried by heating to .degree. C. to obtain an unsintered porcelain sheet with a thickness of about 25 um. This sheet is long and is used by cutting it into 10 cm squares.

On the other hand, the 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 dissolved in 9.1 g of butylcarpitol were placed in a stirrer and stirred for 10 hours. Then, this conductive paste was made into a piece with a length of 14 mm and a width of 7 m.
After printing on one side of the green porcelain sheet through a screen with 50 m patterns, it was dried.

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. Furthermore, four unsintered porcelain sheets each having a thickness of 60 LLm were laminated on the upper and lower surfaces of this laminate.

Pressure and cutting of the footwear Next, this laminate was heated at a temperature of about 50°C for about 40 minutes in the thickness direction.
The laminate was crimped under a load of 1,000 tons, and then the laminate was cut into a lattice shape to obtain 50 laminate chips.

After firing the layered chip, the stacked chip was 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 1130°C.
Raise the temperature at a rate of 100°C/h to 1130°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.

Outside JLL Kiwami! 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 3N 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 1o
The thickness of the electrode is 0.02 mm, and the opposing area of the pair of internal electrodes 14 is 5 mm x 5 mm = 25 mm 2 . Further, the composition of the dielectric ceramic layer 12 after sintering is substantially the same as the mixed composition of the basic components and additive components before sintering.

Measuring the electrical characteristics of an 11 constant k, multilayer ceramic capacitor 1o,
The average values were calculated, and as shown in Table 2, k, dielectric constant ε, 3590, tan δ 1.0%, resistivity ρ 5.7×10'MΩ'am, and capacitance at 25°C. Rate of change in capacitance Δc- at -55℃ and +125℃ based on standard
55ΔC+28 is -9.5%, +6.0%, and the rate of change in capacitance at -25°C and +85°C based on the capacitance at 20°C is -5.2%.

-3.9%.

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

(A) Relative permittivity c1 is temperature 20'C1 frequency 1kHz
, voltage (effective value) 1. Measure the capacitance under OV conditions,
This measurement value and the opposing area of the pair of internal electrodes 14 are 25 mm.
” was calculated based on the thickness of the dielectric ceramic layer 12 between the pair of internal electrodes 14 of 0.02 mm.

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

tc+resistance resistivity (O cm) between the pair of external electrodes 16 after 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 Dl 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 1k at each temperature of +105℃ and +125℃
Hz, voltage (effective value) 1. The capacitance was measured under OV conditions, 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 sample No. 1 and its characteristics have been described above, but samples No. 2 to 101 have also been described with respect to the composition of the basic component, the first and second additive components, their proportions, and the conditions in a reducing atmosphere. A multilayer ceramic capacitor was prepared in exactly the same manner as for sample No. 1, except that the firing temperature was changed as shown in Tables 1 and 2, and the 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.

In addition, 1-〇, α of the basic component paddle in Table 1 indicates the ratio of the first basic component to the second basic component in moles, k-x-z, x
, z indicates the ratio of the number of atoms of each element in the compositional formula (1) of the basic components described above.

In addition, Mg and Zn in the X column indicate the content of M in the composition formula (1) of the basic component mentioned above, the number of atoms of these is shown in these columns, and the number of these atoms is shown in the total column. The total value (X value) is shown.

Ca and Sr in the Z column indicate the contents of the composition formula (1) of the basic components, the numbers of these atoms are shown in these columns, and the total value ( binary) is shown.

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 as follows: △C-□ (%) and 8C, ,, ( %), 20
The capacitance change rates at -25°C and +85°C based on the capacitance at °C are shown as ΔC-2s (%) and ΔC, , (%).

Table 2 (1) *Marked samples are comparative examples Table 2 (2) *Marked samples i 7 bites Table 2 (3) *Magnetic force H dimension W 躬 7 Table 2 (4) of the school examples marked with * is clear from Table 2 (5) of the μ1 7 schools marked * According to the sample according to the present invention, when fired at 1200°C or lower in a non-oxidizing atmosphere, the dielectric constant ε is 3000 or more, the dielectric loss tan δ is 2.5% or less, and the resistivity ρ is 1X10. 'MΩ・
cm or more, temperature change rate of capacitance △C-6, and △C1
□5 is within the range of -15% to +15%, and the capacitance temperature change rate ΔC-1s and ΔC85 are within the range of -10% to +10%. It is.

On the other hand, No, 11-13, 26, 31, 32° 36.3
7,40.41.49-52,58゜62.67.72
, 84, 93, 94, 100 and 101, it was not possible to obtain ceramic capacitors having the desired electrical characteristics.

Therefore, these samples are outside the scope of this invention.

In addition, Table 2 shows the temperature change rate of capacitance ΔC-5s+
Only ΔCl2S+ ΔC-zs+ ΔCss is shown, but the temperature range from -25°C to +85°C for samples belonging to the scope of the present invention
The temperature change rate ΔC of various capacitances in the range of °C is −10
% to +10%, and -55℃ to +12
The temperature change rate ΔC of various capacitances in the range of 5°C is -1
It falls within the range of 5% to +15%.

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.

If the value of It will be outside, but X+
The value of Z is k, 0.0 as shown in sample No. 42.43.
In case 1, a dielectric ceramic composition having desired electrical properties can be obtained. Therefore, the lower limit of the value of x+z is 0.01.

On the other hand, when the value of x+z is k, 0.12 as shown in sample No. 50.51, ΔCas is -10% to +10%.
%, but when the value of X+Z is k=0.10 as shown in Sample No. 57, a dielectric ceramic composition having desired electrical properties can be obtained.

However, the value of x+z is k as shown in sample No. 49.52.
, 0.07, if the value of Z exceeds 0.05, a dielectric ceramic composition having desired electrical characteristics cannot be obtained. Therefore, the upper limit of X+Z is 0.
10, but at the same time the upper limit of 2 must be set to 0.05.

In addition, Mg and Zn of the M component and Ca and Sr of the L component act in the same manner as f, and Mg
and Zn or both, and O<
One or both of Ca and Sr can be used within a range that satisfies z≦0,05. Then, M component and L
It is desirable that the value of X+Z be in the range of 0.01 to 0.10, regardless of whether one component or several components are used.

The value of y is k as shown in sample No. 67.72.84,
If the value of y is 0.06, a dense sintered body cannot be obtained, but if the value of y is 0.06, sample No. 66°71, . 73.76～
When k is 0.04, as shown in No. 81, a dielectric ceramic composition having desired electrical characteristics can be obtained. Therefore, the upper limit of y is 0.04.

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

Yb 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 there is one type of R component or multiple types of R components, it is desirable that the value of y is in the range of 0.04 or less. Further, if y is 0.04 or less, even a small amount close to 0 will have a certain effect.

In the composition formula, the component represented by R contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, the temperature
Temperature change rate of capacitance ΔC-65 to Δ in the range of 25℃
It becomes possible to easily keep C+zs in the range of -15% to +15%, and the temperature change rate of capacitance ΔC-25 to ΔC6, in the range of -25°C to 85°C, is -10%. ~
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 R component has the effect of increasing the resistivity ρ and the effect of increasing sinterability.

When the value of α is k, zero as shown in sample No. 32.37, the temperature change rate of capacitance ΔC-25 is -lO%~
+10%, ΔC-5 is outside the range of -15% to +15%, but if the value of a is k, 0.005 as shown in sample No. 33.38, the desired value is A dielectric ceramic composition having electrical properties can be obtained.

Therefore, the lower limit value of α is 0.005.

On the other hand, the value of α is k as shown in sample No. 36.40,
In the case of 0.05, the temperature change rate ΔCas of capacitance is outside the range of -10% to +10%, but the value of a is 0.04 as shown in sample No. 35.39. in case of,
A dielectric ceramic composition having desired electrical properties can be obtained.

Therefore, the upper limit value of α is 0.04.

When the value of k is smaller than 1.0 as shown in sample No. 58, the resistivity ρ becomes significantly lower than 1×10'MΩ・cm; As shown in No. 59, when k is 1.00, a dielectric ceramic composition having desired electrical characteristics can be obtained. Therefore, the lower limit value of k is 1.00.

On the other hand, the value of k is 1.0 as shown in sample No. 62.
If it is larger than 5, a dense sintered body cannot be obtained, but
When the value of k is 1.05 as shown in Sample No. 61, a dielectric ceramic composition having desired electrical properties can be obtained. Therefore, the upper limit of k is 1.05.

The amount of the first additive component consisting of Cr z Os and/or A 1 m On was sample No −93+94.1.
As shown in samples No. 00 and 101, if k is more than 3.0 parts by weight, a dense sintered body cannot be obtained even if fired at 1250°C, but as shown in samples No. 190 to 92.99, k,
When the amount added is 3.0 parts by weight, a dielectric ceramic composition having desired electrical properties can be obtained. Therefore,
The upper limit of the first additive component is 3.0 parts by weight.

The first additive component has a certain effect even in a very small amount within the range of 3.0 parts by weight or less.

However, in consideration of variations in electrical properties during mass production, it is desirable to add 0.001 part by weight or more.

Note that the first additive components are Cr2O3 and Al2O.

works in the same way as f, and the same result can be obtained by using one selected from these, or by using a plurality of them.

Whether the first additive component is one type or multiple types, the amount added is desirably within a range of 3.0 parts by weight or less.

This first additive component contributes to improving the temperature characteristics of capacitance. That is, by adding the first additive component, the temperature of -55°C to 1
Temperature change rate of capacitance ΔC-55 to Δ in the range of 25℃
It becomes possible to easily keep C+xs within the range of 5% to +15%, and the temperature change rate of capacitance ΔC-2, ~ΔCas in the range of -25°C to 85°C can be reduced to -lO%. ~
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 first additive component has the effect of slightly increasing the resistivity ρ.

When the amount of the second additive component added is zero, sample No. 26
As shown in k, even if the firing temperature is 1250°C, a dense sintered body cannot be obtained, but when the amount added is 0.2 parts by weight per 100 parts by weight of the basic components, sample No. As shown in Fig. 27, a sintered body having desired electrical properties can be obtained by firing at 1170°C. Therefore, the lower limit of the second additive component is 0.2 parts by weight.

On the other hand, as shown in sample No. 31, when the amount of the second additive component k is 7.0 parts by weight, the dielectric constant ε is 300.
However, as shown in sample No. 30, when k is added in an amount of 5.0 parts by weight, ΔCss is outside the range of -10% to +lO%. Solids are obtained. Therefore, the upper limit of the amount of the second additive component added is 5.0 parts by weight.

A preferred composition of the second additive component is 820, S in FIG.
It can be determined based on a triangular diagram showing the composition ratio of L 02 M O.

The first point A of the triangular diagram shows the composition of sample No. 1 with 1 mol% of B2O3, 80 mol% of 5iOz, and 19 mol% of MO, and the second point B shows the composition of B2O3 of sample No. 2. 1 mol%, SiO2 39 mol%, and MO 60 mol%.
7) 8203 is 30 mol%, Sin is 0 mol%, MO
shows a composition of 70 mol%, and the fourth spot is sample No. 4.
B2O3 is 90mol%, S i O2 is 0mol%
, MO has a composition of 10 mol %, and the fifth point E is.

Sample No. 5(7)Bz Os is 90'F:)'v%,
It shows a composition of 10 mol% of S i Ox and 0 mol% of MO, and the sixth point F is sample No. 6(7)B20x is 2
0 mol%, 5iOz is 80 mol%, and MO is 0 mol%.

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

On the other hand, if the composition of the second additive component is outside the range specified in the present invention, dense sintered bodies cannot be obtained as shown in Sample Nos. 11 to 13.

Incidentally, the MO acid component 1 is, for example, K, Bad, MgO, and ZnO as shown in Sample No. 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, 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 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 the second additive component. 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 consists of a baked mixture of 3.0 parts by weight or less of the first additive component and 0.2 to 5 parts by weight of the second additive component, and the basic components have ▲ mathematical formulas, chemical formulas, tables, etc. ▼ However, M is Mg and/or Zn, L is Ca and/or Sr, R is Sc, Y, Gd, Dy, Ho, Er, Yb,
One or more metals selected from Tb, Tm, and Lu, α, k, x, z, and y are 0.005≦α≦0.04 1.00≦k≦1.05 0<x< 0.10 0<z≦0.05 0.01≦x+z≦0.10 0<y≦0.04), and the first
The additive component consists of Cr_2O_3 and/or Al_2O_3, and the second additive component consists of B_2O_3, SiO_2, and MO(
However, MO is BaO, SrO, CaO, MgO and Zn
one or more metal oxides selected from O)
The composition range of the B_2O_3, the SiO_2, and the MO is 1 mol% of the B_2O_3, 80 mol% of the SiO_2, and 19 mol% of the MO in the triangular diagram showing these compositions in mol%. a first point A showing a composition of 1 mol % of said B_2O_3, 39 mol % of said SiO_2, and 60 mol % of said MO; A third point C having a composition of 0 mol% of SiO_2 and 70 mol% of the MO; and a fourth point C having a composition of 90 mol% of the B_2O_3, 0 mol% of the SiO_2 and 10 mol% of the MO. Point D, the B_2O_3 is 90 mol%, the SiO_2 is 10
a fifth point E showing a composition in which the MO is 0 mol %; the B_2O_3 is 20 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 0 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, 3.0 parts by weight or less of the first added component, and 0.2 to 5 parts by weight of the second added component, and the basic component is (1-α). {(Ba_k_−_x_−_zM_xL_z
)O_k(Ti_1_-_yR_y)O_2_-_y_
/_2}+αBaZrO_3 (However, M is Mg and/or Zn, L is Ca and/or Sr, R is Sc, Y, Gd, Dy, Ho, Er, Yb,
One or more metals selected from Tb, Tm, and Lu, α, k, x, z, and y are 0.005≦α≦0.04 1.00≦k≦1.05 0<x< 0.10 0<z≦0.05 0.01≦x+z≦0.10 0<y≦0.04), and the first
The additive component consists of Cr_2O_3 and/or Al_2O_3, and the second additive component consists of B_2O_3, SiO_2, and MO(
However, MO is BaO, SrO, CaO, MgO and Zn
one or more metal oxides selected from O), and the composition range of the B_2O_3, the SiO_2, and the MO is such that the B_2O_3 is 1 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 third point C has a composition of 30 mol% of B_2O_3, 0 mol% of SiO_2, and 70 mol% of MO; and 90 mol% of B_2O_3 and 0 mol% of SiO_2. a fourth point D showing a composition in which the MO is 10 mol %, the B_2O_3 is 90 mol %, and the SiO_2 is 10 mol %;
The fifth point E shows a composition in which the MO is 0 mol %, the B_2O_3 is 20 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 the sixth point F showing a composition of 0 mol %.