JPH06251987A - Ceramic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a ceramic capacitor, which is small in size, large in capacity, and high in CR product at a high temperature, at a low cost. CONSTITUTION:A dielectric ceramic composition is composed of 100.0 parts by weight of basic component and 0.2 to 5.0 parts by weight of additive component, wherein the basic component is expressed by a composition formula, (1-alpha)(Bak-(x+y)MxLy)Ok(Ti1-zRz)O2-z/2+alphaMgNb2O6 (where M is Mg and/or Zn, L is Ca and/or Sr, R is one or more elements selected from Sc, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and the additive component is composed of B2O3, SiO2, and MO (where MO is one or more kinds of oxides selected from BaO, SrO, CaO, MgO, and ZnO).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-layer or multi-layered ceramic capacitor in which one or more dielectric ceramic layers are sandwiched by at least two internal electrodes, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A laminated ceramic capacitor is generally manufactured by the following method. That is, a ceramic green sheet is prepared by a doctor blade method or the like, a pattern of a metal powder paste to be an internal electrode is printed on the green sheet, and a plurality of the green sheets are stacked and thermocompression-bonded in an oxidizing atmosphere. 1300 ° C
It is manufactured by firing at the above temperature to make a sintered body, and baking an external electrode that is electrically connected to the internal electrode on the end surface of the sintered body.

Here, the material of the internal electrodes is palladium,
Noble metals such as platinum and silver-palladium do not come into contact with the ceramic to be oxidized or directly react with the ceramic even under the above-mentioned manufacturing conditions. Therefore, such a precious metal has been used as a material for the internal electrodes of the laminated ceramic capacitor. However, since these precious metals are expensive, they have the drawback of increasing the cost of the laminated ceramic capacitor. Therefore, in order to reduce the cost of the laminated ceramic capacitor, it has been attempted to use a base metal such as nickel as a material for the internal electrodes.

However, when a base metal such as nickel is used as the material for the internal electrodes, the nickel is oxidized by firing in an oxidizing atmosphere, and the oxidized nickel easily reacts with the ceramic, so that the desired internal electrodes are not formed. In this case, it is possible to perform firing in a reducing atmosphere in order to prevent oxidation of the internal electrodes. However, if firing is performed in a reducing atmosphere while leaving the composition of the ceramic to be the dielectric as it is. , The ceramic is reduced to a semiconductor, and the obtained product does not function as a capacitor.

Therefore, in order to solve such a problem,
Many dielectric porcelain compositions have been proposed. For example, in JP-A-3-278416, (Ba _{k- (x + y)} M _x L _y ) O
_k (Ti _{1- z} R _z ) O _{2-z / 2} (where M is Mg and / or Zn,
L is Ca and / or Sr, R is Sc, Y, Gd, D
a basic component composed of one or more elements selected from y, Ho, Er and Yb), and B ₂ O ₃ and SiO ₂
And MO (where MO is one or more oxides selected from BaO, CaO and SrO), and a dielectric porcelain composition is disclosed.

Further, Japanese Patent Laid-Open No. 3-2781212 discloses (Ba _kx M _x ) O _k (Ti _1-z R _z ) O _{2-z / 2} (where M is Ca and / or Sr and R is Sc, Y, Gd, Dy, Ho, Er
A basic component and consisting of the one or more elements) selected from _{Yb, B 2 O 3, SiO} 2 and MO (where, MO is selected BaO, from CaO and SrO 1
And an additive component consisting of two or more kinds of oxides) are disclosed.

Further, in JP-A-3-278414, (Ba _kx M _x ) O _k (Ti _1-z R _z ) O _{2-z / 2} (where M is Mg and / or Zn and R is Sc, Y, Gd, Dy, Ho, Er
A basic component and consisting of the one or more elements) selected from _{Yb, B 2 O 3, SiO} 2 and MO (where, MO is selected BaO, from CaO and SrO 1
And an additive component consisting of two or more kinds of oxides) are disclosed.

The dielectric ceramic composition disclosed in these documents can be obtained by firing at 1200 ° C. or lower in a non-oxidizing atmosphere, its relative permittivity is 3000 or more, and resistivity ρ is 1 × 10 ^6. MΩ · cm or more, dielectric loss ta
nδ is 2.5% or less, and the temperature change rate of the relative dielectric constant is −5.
-15% to + 15% (based on 25 ° C) at 5 ° C to 125 ° C, -10% to + 10% (20 ° C at 25 ° C to 85 ° C)
It is possible to obtain a porcelain capacitor in the range of ().

[0009]

By the way, in recent years, with the miniaturization and high density of electronic circuits, further miniaturization and larger capacity of laminated ceramic capacitors have been demanded. As a method for reducing the size and increasing the capacity of the laminated ceramic capacitor, it is conceivable to thin the dielectric ceramic layer and increase the number of laminated layers. However, if the dielectric porcelain layer is made too thin, the insulation resistance of the dielectric porcelain layer will decrease, and the CR product at high temperatures will become significantly worse.

The present invention is to provide a small-sized large-capacity porcelain capacitor having a large CR product at a high temperature at a low cost.

[0011]

A porcelain capacitor according to the present invention comprises one or more dielectric porcelain layers made of a dielectric porcelain composition, and at least two or more interiors sandwiching the dielectric porcelain layer. And an electrode, wherein the dielectric ceramic composition comprises 100.0 parts by weight of a basic component and 0.2 to
It is composed of 5.0 parts by weight of an additive component, and the basic component is
Compositional formula (1−α) (Ba _{k- (x + y)} M _x Ly _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} + αMgNb ₂ O ₆ (1) (where M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
It consists of a substance represented by one or more elements selected from r, Tm, Yb and Lu), and the additive component is B ₂ O ₃ , SiO ₂ and MO (where MO is BaO, Sr).
O, CaO, MgO and ZnO).

In the composition formula (1) of the basic component, the value of α is preferably in the range of 0.001 ≦ α ≦ 0.01. When the value of α is within this range, a dense dielectric ceramic composition having desired electrical characteristics can be obtained, but when the value of α is less than 0.001, the CR product at 150 ° C is reduced. Becomes 200 F · Ω or less, and the relative permittivity ε _s
Is less than 3300, and the value of α exceeds 0.01, the CR product at 150 ° C. is less than 200 F · Ω, tan δ exceeds 2.5%, and the resistivity ρ is 4.0 ×.
It becomes smaller than 10 ⁶ MΩ · cm, the rate of change in capacitance ΔC ₋₅₅ , ΔC ₁₂₅ is out of the range of −15% to + 15%, and ΔC ₋₂₅ , ΔC ₈₅ is in the range of −10% to + 10%. Because it will come off.

In the composition formula (1) of the basic component,
The value of k is preferably in the range of 1.00 ≦ k ≦ 1.05.
When the value of k is within this range, a dense dielectric ceramic composition having desired electrical characteristics can be obtained,
When the value of k is less than 1.00, the resistivity ρ is 4.00 ×
It becomes smaller than 10 ⁶ MΩ · cm, the rate of change in capacitance ΔC ₋₅₅ , ΔC ₁₂₅ is out of the range of −15% to + 15%, and ΔC ₋₂₅ , ΔC ₈₅ is in the range of −10% to + 10%. If the value of k exceeds 1.05 and the CR product at 150 ° C falls below 200 F · Ω, 125
This is because it becomes impossible to obtain a dense sintered body by firing at 0 ° C.

In the composition formula (1) of the basic component,
The value of x + y is preferably in the range of 0.01 ≦ x + y ≦ 0.10. When the value of x + y is within this range, a dense dielectric ceramic composition having desired electrical characteristics can be obtained. However, when the value of x + y is less than 0.01, the capacitance changes with temperature. If the rate ΔC ₋₅₅ is out of the range of −15% to + 15% and the value of x + y exceeds 0.10, the temperature change rate ΔC _{85 of the} capacitance is out of the range of −10% to + 10%. Is.

However, even if x + y ≦ 0.10, y
≦ 0.05 is preferable. This is because even if x + y ≦ 0.10 is satisfied, if the value of y exceeds 0.05, the temperature change rate ΔC _{85 of the} capacitance falls outside the range of −10% to + 10%.

It should be noted that Mg and Zn as the M component and Ca and Sr as the L component work almost the same, and one or both of Mg and Zn should be used in the range satisfying 0 ≦ x <0.10. Further, one or both of Ca and Sr can be used within a range satisfying 0 ≦ y ≦ 0.05.

In the composition formula (1) of the basic component,
The value of z is preferably in the range of 0.002 ≦ z ≦ 0.06. When the value of z is within this range, a dense dielectric porcelain composition having desired electrical characteristics can be obtained, but when the value of z is less than 0.002, the capacitance changes with temperature. The rate ΔC _-55 is out of the range of -15% to + 15%,
This is because if ΔC _-25 is out of the range of -10% to + 10% and the value of z exceeds 0.06, a dense sintered body cannot be obtained.

The R component Sc, Y, Gd, Tb, D
y, Ho, Er, Tm, Yb and Lu work almost in the same way, and the same result can be obtained by using one selected from these or a combination of a plurality of them.

In the composition formula (1) of the basic component, k- (x + y) is the proportion of the number of Ba atoms, x is the proportion of the M component atoms, and y is the proportion of the L component atoms. The ratio, z
Indicates the ratio of the number of atoms of the R component.

Further, among the basic components, Cr ₂ O ₃ , M
Sinterability may be improved by adding a trace amount of one or more oxides selected from nO, Fe ₂ O ₃ , CoO and NiO. The amount of oxide added is Cr, Mn, Fe, Co,
As Ni, 1.0 atomic% or less is preferable. In addition, other substances may be added to the basic components as needed. Further, starting materials for obtaining the basic components may be oxides or hydroxides such as BaO, SrO, CaO or other compounds other than those shown in the examples.

Next, the range of addition amount of the additive component is set to 100.
The content of 0.2 to 5.0 parts by weight with respect to the basic components of parts by weight means that when the amount of the added component is in this range, a dense dielectric ceramic composition having desired electrical characteristics is obtained. Although it can be obtained, if the added amount of the additive component is less than 0.2 parts by weight, a dense sintered body cannot be obtained even by firing at 1250 ° C., and the added amount of the additive component is 5.0 parts by weight. This is because, when the content exceeds the range, the relative permittivity ε _s becomes less than 3300, and the temperature change rate ΔC _{−55 of the} capacitance falls outside the range of −15% to + 15%.

The composition of the additive component is B ₂ O ₃ --Si.
In the triangular diagram showing the composition ratio of O ₂ -MO in mol%, B
₂ O ₃ is 1 mol%, SiO ₂ is 80 mol%, MO is 19
The first point A indicating the composition of mol%, the second point B indicating the composition of 1 mol% of B ₂ O _3, 39 mol% of SiO ₂ , and 60 mol% of MO, and B ₂ O ₃ The third point C showing the composition of 29 mol%, 1 mol% of SiO ₂ , and 70 mol% of MO.
And B ₂ O ₃ is 90 mol%, SiO ₂ is 1 mol%, MO
Is 9 mol% and the fourth point D is 90 mol%, and B ₂ O ₃ is 90 mol%.
A fifth point E showing a composition of mol%, SiO ₂ 9 mol% and MO 1 mol%, and a composition of 19 mol% B ₂ O _3, 80 mol% SiO _{2 and} 1 mol% MO. It is preferably located in a region surrounded by six straight lines connecting the sixth point F shown in this order.

The composition of the additive components is thus changed to B ₂ O ₃
The first to the third triangular diagrams showing the composition ratio of SiO ₂ -MO in mol%
The area surrounded by the six straight lines connecting the points A to F in the order of 6 is set to be a dense dielectric ceramic composition having desired electrical characteristics if the composition of the additive component is in this area. However, if the composition of the additive component is outside this range,
This is because a dense sintered body cannot be obtained by firing at 1250 ° C. The starting material for the additive component may be another compound such as oxide or hydroxide.

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

Here, the non-oxidizing atmosphere may be not only a reducing atmosphere such as H ₂ or CO but also a neutral atmosphere such as N ₂ or Ar. The firing temperature in the non-oxidizing atmosphere can be variously changed in consideration of the electrode material. When nickel is used as the material of the internal electrode, the firing temperature is 1
In the range of 050 to 1200 ° C, the heat treatment can be performed with almost no agglomeration of nickel particles.

The heat treatment temperature in the oxidizing atmosphere may be lower than the firing temperature in the non-oxidizing atmosphere, and is preferably in the range of 500 ° C to 1000 ° C.
The oxidizing atmosphere is not limited to the atmospheric atmosphere, and for example, an atmosphere having a low oxygen concentration, such as N ₂ mixed with several ppm of O ₂ , or an atmosphere having an arbitrary oxygen concentration can be used. The electrode material (nickel, etc.) determines the temperature and the oxygen concentration in the atmosphere.
Therefore, it is necessary to make various changes in consideration of the oxidation of the above and the oxidation of the dielectric ceramic layer. In the examples described later, this heat treatment temperature is 60
Although the temperature is 0 ° C., it is not limited to this temperature.

In the examples described later, the heat treatment in the non-oxidizing atmosphere and the heat treatment in the oxidizing atmosphere are carried out in one continuous firing profile. Of course, the firing step in the non-oxidizing atmosphere is performed. It is also possible to separately perform the heat treatment step in the oxidizing atmosphere and the heat treatment step.

Further, in the embodiment, the Zn electrode is used as the external electrode, but Ni, Ag, Cu, etc. electrodes can be used by selecting the electrode baking conditions, and the Ni external electrode is not used. It is also possible to apply the coating to the end face of the fired laminate to fire the laminate and to bake the external electrodes at the same time.

The contents of the basic components and the contents of the added components are exactly the same as in the case of the above-mentioned ceramic capacitor. Further, the present invention can of course be applied to a general single-layer ceramic capacitor other than the laminated ceramic capacitor.

[0030]

EXAMPLES First, the case of sample No. 1 will be described.
In the case of sample No. 1, the starting material used has a purity of 9
9.0% or more of BaCO ₃ , MgO, ZnO, CaCO
Powders of ₃ , SrCO ₃ , TiO ₂ and Er ₂ O ₃ were prepared, and the composition formula (1−α) (Ba _{k- (x + y)} M _x Ly _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} ＋ αMgNb ₂ O ₆ ... (Ba _{k- (x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z /} in the first term in (1) _{2 The} powder was weighed as follows so that (2) becomes (Ba _0.96 Mg _0.03 Zn _0.01 Ca _0.01 Sr _0.01 ) O _1.02 (Ti _0.98 Er _0.02 ) O _1.99 (3). BaCO ₃ 1029.33g MgO 6.57g ZnO 4.42g CaCO ₃ 5.43g SrCO ₃ 8.02g TiO ₂ 425.44g Er ₂ O ₃ 20.78g

Next, these powders were ball milled for about 20 minutes.
After wet-mixing for 4 hours, drying at 150 ° C for 4 hours, pulverizing, and pulverizing this pulverized material in the atmosphere at about 1200 ° C for 2 hours to prepare the composition of the first term in the composition formula (1) of the basic component. A powder was obtained.

Next, the second component in the composition formula (1) of the basic component
In order to obtain the term MgNb ₂ O ₆ , MgCO ₃ , Nb ₂
The O ₅ powder was weighed as follows. MgCO ₃ 240.81g Nb ₂ O ₅ 759.19g

Next, these were wet mixed in a ball mill for about 20 hours, dried at 150 ° C. for 4 hours and then pulverized. The pulverized product was calcined at about 1100 ° C. for 2 hours in the atmosphere, and MgNb ₂ O ₆ powders were obtained.

In order to obtain the basic component in the case of sample No. 1, the basic component is adjusted so that 1-α in the composition formula (1) of the basic component is 0.995 mol and α is 0.005 mol. 99.5 parts by mole of the component powder of the first item (995.4
2 g) and 0.5 parts by mole of the component powder of the second item of the basic component (4.58 g) are mixed to obtain 1000 g of the basic component powder.
Got

On the other hand, in order to obtain the additive component of sample No. 1, B ₂ O ₃ 30.54 g SiO ₂ 52.71 g CaCO ₃ 11.71 g SrCO ₃ 2.16 g BaCO ₃ 2.89 g were weighed, and 300 cc of alcohol was added to these, and polyethylene was added. After stirring for 10 hours using alumina balls in a pot, it was calcined in the air at 1000 ° C. for 2 hours, and this was 3
It was placed in an alumina pot with 00 cc of alcohol, pulverized with an alumina ball for 15 hours, and then dried at 150 ° C. for 4 hours to obtain 30 mol% B ₂ O _3, 60 mol% SiO ₂ , and 10 mol% MO. (CaO: 8 mol%, S
A powder of the additive component having a composition of rO: 1 mol% and BaO: 1 mol% was obtained.

Next, 1000 g (100
10 parts by weight (1 part by weight) of the powder of the above-mentioned additional component is added to the total weight of the basic component and the additional component by adding an organic binder composed of an aqueous solution of acrylic acid ester polymer, glycerin and condensed phosphate. On the other hand, 15% by weight was added, and further 50% by weight of water was added, and these were put in a ball mill, pulverized and mixed to prepare a slurry of a porcelain raw material. In this example, no sintering aid such as Cr ₂ O ₃ or MnO was added, but when a sintering aid is added, it is added at this stage.

Next, the slurry was placed in a vacuum defoamer for defoaming, the slurry was placed in a reverse roll coater, and this was used to form a thin film based on this slurry on a polyester film. On the film 1
It was heated to 00 ° C. and dried to obtain a green sheet having a thickness of about 25 μm. This sheet was punched into a 10 cm square and used.

On the other hand, as the conductive paste for the internal electrodes, 10 g of nickel powder having an average particle size of 1.5 μm and 0.9 g of ethyl cellulose dissolved in 9.1 g of butyl carbitol were placed in a stirrer for 10 hours. Obtained by stirring. This conductive paste was printed on one side of the green sheet through a screen having 50 patterns each having a length of 14 mm and a width of 7 mm, and then dried.

Next, two green sheets were laminated with the printing surface facing up. At this time, the adjacent upper and lower sheets were arranged such that their printing surfaces were displaced by about half in the longitudinal direction of the pattern. Further, 10 unprinted green sheets were laminated on each of the upper and lower surfaces of this laminate. Next, this laminate was pressed at a temperature of about 50 ° C. by applying a pressure of about 40 tons in the thickness direction. After that, the laminate was cut into a lattice shape to obtain about 50 laminated chips.

Next, this laminated chip is placed in a furnace capable of firing in an atmosphere, and 60 at a rate of 100 ° C./hr in an air atmosphere.
The organic binder was burned by heating to 0 ° C. Then, the atmosphere of the furnace was changed from the atmosphere to H ₂ (2% by volume) + N ₂ (98
The atmosphere was changed to (volume%). Then, the furnace is kept in the reducing atmosphere as described above, the heating temperature of the laminated chip is maintained from 600 ° C. to the firing temperature of 1150 ° C. (maximum temperature) for 3 hours, and then 600 ° C. at 100 ° C./hr. The temperature is lowered to ℃, the atmosphere is replaced with an air atmosphere (oxidizing atmosphere), and the temperature is kept at 600 ° C. for 30 minutes to perform an oxidation treatment
Then, it cooled to room temperature and obtained the laminated sintered compact chip 15 (refer FIG. 1).

Next, the laminated sintered body chip 1 in which the electrodes are exposed
A conductive paste composed of zinc, glass frit and vehicle is applied to the side surface of No. 5 and dried.
The zinc electrode layer 18 is formed by baking at a temperature of 0 ° C. for 15 minutes, and a copper layer 20 is further deposited thereon by electroless plating,
Further, a Pb-Sn solder layer 22 was provided thereon by electroplating to form a pair of external electrodes 16, 16.

As a result, as shown in FIG. 1, a laminated ceramic capacitor 10 including the dielectric ceramic layer 12, the internal electrode 14, and the external electrodes 16 and 16 was obtained. The thickness of the dielectric ceramic layer 12 of the laminated ceramic capacitor 10 is 0.
02 mm, the facing area of the internal electrode 14 is 5 mm × 5 mm
= 25 mm ² . In addition, the dielectric ceramic layer 12 after sintering
The composition is substantially the same as the composition of the mixture of the basic component and the additive component before sintering.

Next, when the electrical characteristics of the laminated ceramic capacitor 10 were measured, as shown in Table 3, the relative permittivity ε was obtained.
_s is 3560, tan δ is 1.0%, and resistivity ρ is 5.9.
× 10 ⁶ MΩ · cm, CR product at 150 ° C is 31
5F · Ω, capacitance change rate ΔC _-55 , ΔC _{125 of} -55 ℃ and +125 ℃ based on the capacitance of 25 ℃-
12.1%, + 6.1%, rate of change in capacitance at -25 ° C, + 85 ° C based on capacitance at 20 ° C ΔC _-25 , Δ
C ₈₅ is -7.2%, - 4.9%.

The electrical characteristics were measured as follows. (A) For the relative permittivity ε _s , the capacitance was measured under the conditions of a temperature of 20 ° C., a frequency of 1 kHz, and a voltage (effective value) of 1.0 V. The measured value and the facing area of a pair of internal electrodes (25 mm ² ) And the thickness of the dielectric ceramic layer between the pair of internal electrodes is 0.02 mm. (B) Dielectric loss tan δ (%) was measured under the same conditions as in the measurement of the relative permittivity. (C) The resistivity ρ (MΩ · cm) is D at a temperature of 20 ° C.
After applying C100V for 60 seconds, the resistance value between the pair of external electrodes was measured, and the resistance value was calculated based on the measured value and the dimension. (D) High temperature CR product (F · Ω) is 150 ° C and frequency is 1
Capacitance is measured under the conditions of kHz and voltage (effective value) of 1.0 V, and then DC 100 V is applied for 60 seconds, and then a resistance value between a pair of external electrodes is measured to measure the capacitance. The product of the resistance value and the resistance value was calculated. (E) For the temperature characteristics of capacitance, place the sample in a constant temperature bath,
55 ° C, -25 ° C, 0 ° C, + 20 ° C, + 25 ° C, +50
At each temperature of ℃, +85 ℃, +110 ℃, +125 ℃, measure the capacitance under the condition of frequency 1kHz, voltage (effective value) 1.0V, and the capacitance at the temperature of 20 ℃ and 25 ℃ It was obtained by calculating the rate of change in capacitance at each temperature.

Although the case of sample No. 1 has been described above, also in the case of sample Nos. 2 to 87, the compositions and ratios of the basic component and the additive component, and the firing temperature in the reducing atmosphere are changed. A laminated porcelain capacitor was prepared by the same method as in the case of Sample No. 1, and its electrical characteristics were measured by the same method.

Tables 1 to 1 show the compositions and proportions of basic components for each sample, and Tables 2 to 2 show the compositions and proportions of additive components for each sample.
Tables 3 to 3 show the firing temperature and the electrical characteristics of the laminated ceramic capacitors for each sample.

The numerical values in the columns of x, y, k in Tables 1 to 3 are the numbers of atoms of each element of the composition formula (1) of the basic component described above,
That is, the ratio of the number of atoms of each element when the number of atoms of (Ti + R) is 1 is shown.

Further, in Tables 1 to 1, Mg and Zn in the column x are
Indicates the content of M in the composition formula (1) of the basic component described above, Ca and Sr in the column of y indicate the content of L in the composition formula (1) of the basic component, and Sc and Y in the column of z. , Gd, T
b, Dy, Ho, Er, Tm, Yb and Lu represent the contents of R in the composition formula (1) of the basic component described above.

Further, the addition amount of the additional components shown in Table 2 is
It is given in parts by weight with respect to 100 parts by weight of the basic component.
In the column of MO of the additive component, BaO, SrO, CaO, M
The proportions of gO and ZnO are given in mol%. Also,
The amount of the sintering aid added is Cr, Mn, Fe, C with respect to 1 mol part of the basic component in the composition formula (1) of the basic component described above.
The proportions of o and Ni are shown in atomic%.

Further, in Tables 3 to 5, the temperature characteristics of the capacitance are ΔC ₋₅₅ (%) and Δ, which are the rate of change of the capacitance at −55 ° C. and + 125 ° C. with reference to the capacitance at 25 ° C.
C _{12 5} (%), -25 relative to the electrostatic capacitance of 20 ° C.
The rate of change in capacitance at ° C and + 85 ° C is shown as ΔC _-25 (%) and ΔC ₈₅ (%).

[0051]

[Table 1]

[0052]

[Table 1]

[0053]

[Table 1]

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 2]

[0057]

[Table 2]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 3]

[0061]

[Table 3]

[0062]

[Table 3]

As is clear from Table 1, Table 2 and Table 3, according to the examples according to the present invention, the relative dielectric constant ε of the dielectric layer can be obtained by firing at 1200 ° C. or lower in a non-oxidizing atmosphere. _s is 3300 or more, resistivity ρ is 4.0
× 10 ⁶ MΩ · cm or more, tan δ is 2.5% or less, CR product at 150 ° C. is 200 F · Ω or more, and temperature change rate of capacitance ΔC ₋₅₅ and ΔC ₁₂₅ is −15% or more.
Within the range of + 15%, ΔC _-25 and ΔC ₈₅ are -10% to +
It is possible to obtain a laminated ceramic capacitor having electric characteristics within the range of 10%.

On the other hand, sample numbers 2, 5, 17 and 2
2,23,25-27,30,31,35,36,3
According to the examples of Nos. 8, 43, 51-55, 71-77 and 82, it is not possible to obtain a porcelain capacitor having the electrical characteristics aimed at by the present invention. It is out of range.

Tables 3 to 3 show the temperature change rate ΔC of capacitance.
Only _-55 , ΔC ₁₂₅ , ΔC _-25 , and ΔC ₈₅ are displayed, but in the embodiment according to the present invention, −25 ° C. to + 85 ° C.
The temperature change rate ΔC of the capacitance in the range of −10% to +1
It is within the range of 0%, and is -55 ° C to +125.
The temperature change rate ΔC of the capacitance in the range of ℃ is −15% to +
It is within the range of 15%.

Next, the proper range of the composition of the dielectric ceramic composition used in the ceramic capacitor according to the present invention will be examined with reference to the experimental results shown in Table 1, Table 2 and Table 3. .

First, the proper range of the value of α will be examined. When α = 0.001 (Sample No. 3), desired electrical characteristics are obtained, but α = 0 (Sample No. 2)
In this case, the CR product at 150 ° C. becomes 200 F · Ω or less, and the relative dielectric constant ε _s becomes 3300 or less. Therefore, the lower limit value of α is 0.001.

When α = 0.01 (sample No. 4), desired electrical characteristics can be obtained, but α = 0.
In the case of 015 (sample number 5), C at 150 ° C
The R product becomes 200 F · Ω or less, the tan δ exceeds 2.5%, the resistivity ρ becomes smaller than 4 × 10 ⁶ MΩ · cm, and the capacitance temperature change rates ΔC ₋₅₅ and ΔC ₁₂₅ are −15.
%-+ 15% out of the range, ΔC _-25 , ΔC ₈₅ -1
It is out of the range of 0% to + 10%. Therefore, the upper limit of α is 0.01.

Next, the proper range of the value of k will be examined. When k = 1.00 (sample number 32), desired electrical characteristics are obtained, but when k <1.00 (sample numbers 30 and 31), the resistivity ρ is 4. 0 x 10 ⁶
Significantly smaller than MΩ · cm, the temperature change rate of capacitance ΔC ₋₅₅ , ΔC ₁₂₅ is out of the range of −15% to + 15%, and ΔC ₋₂₅ , ΔC ₈₅ is from −10% to + 10%. The CR product at 150 ° C becomes significantly smaller than 200 F · Ω. Therefore, the lower limit of k is 1.
00.

When k = 1.05 (sample number 34), desired electrical characteristics are obtained, but k>
In the case of 1.05 (sample numbers 35 and 36), 1250
A dense sintered body cannot be obtained by firing at ℃. Therefore, the upper limit of k is 1.05.

Next, the proper range of the value of x + y will be examined. In the case of x + y = 0.01 (sample numbers 18 and 19), desired electrical characteristics can be obtained, but x + y =
In the case of 0 (Sample No. 17), the temperature change rate ΔC _{−55 of the} capacitance is out of the range of −15% to + 15%. Therefore, the lower limit value of x + y is 0.01.

X + y = 0.10 (Sample No. 28,
In the case of 29), desired electrical characteristics can be obtained, but in the case of x + y = 0.11 (sample numbers 23, 25, 27), the temperature change rate ΔC _{85 of} capacitance is −10. % To +
It is out of the range of 10%. Therefore, the upper limit of x + y is 0.10.

However, even if x + y ≦ 0.10, y
When the value exceeds 0.05 (Sample Nos. 22 and 26), the temperature change rate ΔC _{85 of the} capacitance is out of the range of −10% to + 10%. Therefore, the value of x + y is 0.01 ≦
x + y ≦ 0.10, but at the same time y ≦ 0.0
Must be 5.

It should be noted that Mg and Zn of the M component work almost in the same manner, and one or both of Mg and Zn can be used within a range satisfying 0 ≦ x <0.10. Ca and Sr work almost in the same manner, and one or both of Ca and Sr can be used in a range satisfying 0 ≦ y ≦ 0.05. However, in the case of using one or more of the M component and the L component, the value of x + y is
The range must be 0.01 ≦ x + y ≦ 0.10.

Next, the appropriate range of the value of z will be examined. When z = 0.002 (sample number 39), desired electrical characteristics are obtained, but z = 0 (sample number 3).
In the case of 8), the temperature change rate ΔC _{-55 of} capacitance is -1.
Deviates from 5% to + 15%, and ΔC _-25 is -10% to +10
%, The CR product at 150 ° C is 200F ・ Ω
It becomes the following. Therefore, the lower limit of z is 0.002
Is.

When z = 0.06 (sample No. 42), desired electrical characteristics can be obtained, but z =
In the case of 0.07 (Sample No. 43), a dense sintered body cannot be obtained by firing at 1250 ° C. Therefore, the upper limit of z is 0.06.

The R component Sc, Y, Gd, Tb, and D
Each of y, Ho, Er, Tm, Yb and Lu works almost in the same manner, and the same effect can be obtained by using one selected from these or by using a plurality of them in combination. .

Next, the proper range of the amount of the added component will be examined. When the added amount of the additive component is 0.2 parts by weight (sample number 78) with respect to 100 parts by weight of the basic component,
The desired electrical characteristics can be obtained by firing at 1190 ° C, but if 0 parts by weight (Sample No. 77) is used, it is 1250 ° C.
A dense sintered body cannot be obtained by firing. Therefore, the lower limit of the addition amount of the additive component is 0.
2 parts by weight.

In addition, the addition amount of the additive component is 10
In the case of 5.0 parts by weight (Sample No. 81) with respect to 0 parts by weight, desired electrical characteristics can be obtained, but in the case of 7.0 parts by weight (Sample No. 82), the relative dielectric Rate is 3300
And the temperature change rate of capacitance ΔC _-55 is -15%.
It goes out of ~ + 15%. Therefore, the upper limit of the added amount of the additive component is 5.0 parts by weight with respect to 100 parts by weight of the basic component.

Next, the composition range of the additive component is B ₂ O ₃ −
Triangle diagram showing the composition ratio of SiO ₂ -MO in mol% (Fig. 2)
Within the range surrounded by six straight lines connecting the first to sixth points A to F in order. The first point A in the triangle diagram is B ₂ O ₃
1 mol%, SiO ₂ 80 mol%, MO 19 mol%
The composition of (Sample No. 61) is shown, and the second point B is B ₂ O ₃
Is 1 mol%, SiO ₂ is 39 mol%, and MO is 60 mol% (Sample No. 62). The third point C is B ₂
O ₃ is 29 mol%, SiO ₂ is 1 mol%, MO is 70 mol% (Sample No. 63), and the fourth point D is B.
₂ O ₃ is 90 mol%, SiO ₂ is 1 mol%, MO is 9 mol% (Sample No. 64), and the fifth point E is B
₂ O ₃ is 90 mol%, SiO ₂ is 9 mol%, MO is 1 mol% (Sample No. 65), and the sixth point F is B
₂ O ₃ is 19 mol%, SiO ₂ is 80 mol%, MO is 1
The composition of mol% (Sample No. 66) is shown.

The composition range of the additive component is B ₂ O
Within the range surrounded by six straight lines connecting the first to sixth points A to F in the triangular diagram (FIG. 2) showing the composition ratio of _3- SiO ₂ -MO in mol% (sample numbers 61 to 70) However, if the composition range of the additive component is out of the above range (Sample Nos. 71 to 76), it will be 12
A dense sintered body cannot be obtained by firing at 50 ° C.

The MO component is, as shown in the case of sample numbers 83 to 87, BaO, SrO, CaO,
Any one of MgO and ZnO may be used, or an appropriate ratio of two or more may be used as shown in other samples.

Next, the sintering aids Cr, Mn, Fe,
The amount of Co and Ni added was 1.0 atomic% (sample number 56 to
In the case of 60), desired electrical characteristics can be obtained, but in the case of 1.5 atom% (sample numbers 51 to 55),
The relative permittivity ε _s becomes 3300 or less. Therefore,
The addition amount of the sintering aid is preferably 1.0 atomic% or less.

[0084]

According to the present invention, the relative permittivity ε _{s of the} dielectric layer is 3300 or more and the resistivity ρ is 4.0 × 10 ⁶ MΩ.
cm or more, tan δ is 2.5% or less, CR product at 150 ° C. is 200 F · Ω or more, and temperature change rate of capacitance is −55 ° C. to 125 ° C. −15% to + 15% (25
-10% to + 10% at -25 ° C to 85 ° C
It is possible to provide a porcelain capacitor in the range (referenced to 20 ° C.).

[Brief description of drawings]

FIG. 1 is a sectional view of a laminated ceramic capacitor according to an embodiment of the present invention.

FIG. 2 is a triangular diagram showing a composition range of an additive component of a dielectric ceramic composition forming a dielectric layer of a ceramic capacitor according to the present invention.

[Explanation of symbols]

 12 Dielectric Ceramic Layer 14 Internal Electrode 15 Laminated Sintered Body Chip 16 External Electrode 18 Zinc Electrode Layer 20 Copper Layer 22 Pb-Sn Solder Layer

[Table 1 ○ 1]

[Table 1 ○ 2]

[Table 1 ○ 3]

[Table 1 ○ 4]

[Table 2 ○ 1]

[Table 2 ○ 2]

[Table 2 ○ 3]

[Table 2 ○ 4]

[Table 3 ○ 1]

[Table 3 ○ 2]

[Table 3 ○ 3]

[Table 3-4]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kishi 6-16-20 Ueno Taito-ku, Tokyo Inside Taiyo Induction Co., Ltd.

Claims (4)

[Claims] 1. A ceramic capacitor comprising one or more dielectric porcelain layers made of a dielectric porcelain composition and at least two or more internal electrodes sandwiching the dielectric porcelain layer, wherein the dielectric The porcelain composition is formed by firing a mixture of 100.0 parts by weight of the basic component and 0.2 to 5.0 parts by weight of the additive component, and the basic component has the composition formula (1-α) ( Ba _{k- (x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} + αMgNb ₂ O
₆ (However, M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
One or more elements selected from r, Tm, Yb and Lu, α, k, x, y, z are 0.001 ≦ α ≦ 0.01 1.00 ≦ k ≦ 1.050 ≦ x <0.10 0 ≦ y ≦ 0.05 0.01 ≦ x + y ≦ 0.10 0.002 ≦ z ≦ 0.06), wherein the additive component is B ₂ O ₃ and SiO ₂ and MO (however, MO
Is one or more oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of B ₂ O ₃ , SiO ₂ and MO is In the triangle diagram shown by mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
A first point A showing a composition of MO of 19 mol%, B ₂ O ₃ of 1 mol%, SiO ₂ of 39 mol%,
A second point B showing a composition of MO of 60 mol%, 29 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A third point C showing a composition of MO of 70 mol%, 90 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A fourth point D showing a composition in which the MO is 9 mol%, 90 mol% of the B ₂ O _{3 and} 9 mol% of the SiO ₂ ,
A fifth point E showing the composition of MO of 1 mol%, and a sixth point F showing the composition of 19 mol% of B ₂ O _3, 80 mol% of SiO ₂ , and 1 mol% of MO. A porcelain capacitor characterized by being in a region surrounded by six straight lines connecting and in this order. 2. A dielectric ceramic composition containing Cr, Mn, F
The ceramic capacitor according to claim 1, wherein an oxide of one or more elements selected from e, Co and Ni is contained in a ratio of 1.0 atomic% or less. 3. A step of preparing a mixture of unsintered porcelain powder, a step of forming an unsintered porcelain sheet of the mixture, and a step of forming at least two or more conductive paste films of the unsintered porcelain sheet. And a step of firing the laminate in a non-oxidizing atmosphere, and a step of heat-treating the fired laminate in an oxidizing atmosphere, The mixture of unsintered porcelain powder is composed of 100.0 parts by weight of the basic component and 0.2 to 5 parts by weight of the additional component, and the basic component has the composition formula (1-α) (Ba _{k -(x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} + αMgNb ₂ O
₆ (However, M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
One or more elements selected from r, Tm, Yb and Lu, α, k, x, y, z are 0.001 ≦ α ≦ 0.01 1.00 ≦ k ≦ 1.050 ≦ x <0.10 0 ≦ y ≦ 0.05 0.01 ≦ x + y ≦ 0.10 0.002 ≦ z ≦ 0.06), wherein the additive component is B ₂ O ₃ and SiO ₂ and MO (however, MO
Is one or more oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of B ₂ O ₃ , SiO ₂ and MO is In the triangle diagram shown by mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
A first point A showing a composition of MO of 19 mol%, B ₂ O ₃ of 1 mol%, SiO ₂ of 39 mol%,
A second point B showing a composition of MO of 60 mol%, 29 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A third point C showing a composition of MO of 70 mol%, 90 mol% of B ₂ O _{3 and} 1 mol% of SiO ₂ .
A fourth point D showing a composition in which the MO is 9 mol%, 90 mol% of the B ₂ O _{3 and} 9 mol% of the SiO ₂ ,
A fifth point E showing the composition of MO of 1 mol%, and a sixth point F showing the composition of 19 mol% of B ₂ O _3, 80 mol% of SiO ₂ , and 1 mol% of MO. A method for manufacturing a porcelain capacitor, characterized in that it is in a region surrounded by six straight lines connecting in this order. 4. A dielectric ceramic composition containing Cr, Mn, F
4. The method for manufacturing a porcelain capacitor according to claim 3, wherein an oxide of one or more elements selected from e, Co and Ni is contained at a ratio of 1.0 atomic% or less.