JP2843735B2 - Porcelain capacitor and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic capacitor having a single-layer or laminated structure in which one or more dielectric ceramic layers are sandwiched by at least two or more internal electrodes, and a method of 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 paste pattern of a metal powder serving as an internal electrode is printed on the green sheet, a plurality of the green sheets are stacked and thermocompression-bonded, and in an oxidizing atmosphere, 1300 ° C
It is manufactured by baking at the above temperature to produce a sintered body, and baking an external electrode, which is electrically connected to the internal electrode, on the end face of the sintered body.

Here, the material of the internal electrode is palladium,
Precious metals such as platinum and silver-palladium do not oxidize upon contact with the ceramic or react directly with the ceramic even under the above manufacturing conditions. For this reason, such a noble metal has been used as a material of an internal electrode of a laminated ceramic capacitor. However, since these noble metals are expensive, they have a disadvantage of increasing the cost of the laminated ceramic capacitor. Therefore, in order to reduce the cost of the laminated ceramic capacitor, attempts have been made to use a base metal such as nickel as the material of the internal electrodes.

However, when a base metal such as nickel is used as the material of the internal electrode, the nickel is oxidized by firing in an oxidizing atmosphere, and the oxidized nickel easily reacts with the ceramic, so that a desired internal electrode is not formed. In this case, in order to prevent the internal electrodes from being oxidized, it is considered that the firing is performed in a reducing atmosphere. However, if the firing is performed in a reducing atmosphere while keeping the composition of the ceramic to be a dielectric material as it is. Then, the ceramic is reduced to become 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, JP-A-3-171715 discloses (1-α) {(Ba _{k- (x + z)}
M _x L _z ) O _k (Ti _1-y R _y ) O _{2-y / 2} } + αCaZrO ₃ (where M is Mg and / or Zn, L is Ca and / or Sr, R is S
one or two or more elements selected from c, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu), B ₂ O ₃ , SiO ₂ and MO (provided that
A dielectric porcelain composition is disclosed which includes an additive component in which MO is one or more oxides selected from BaO, CaO and SrO).

Japanese Patent Application Laid-Open No. 3-171714 discloses (1-α) {(Ba _kx M _x ) O _k (Ti _1-y R _y ) O _{2 -y / 2} } + αCaZrO
₃ (where M is Ca and / or Sr, R is Sc, Y,
A basic component composed of one or more elements selected from Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu), B ₂ O ₃ , SiO ₂ and MO (where MO is B
A dielectric porcelain composition comprising an additional component comprising one or more oxides selected from aO, CaO and SrO) is disclosed.

Japanese Patent Application Laid-Open No. 3-171712 discloses (1-α) {(Ba _kx M _x ) O _k (Ti _1-y R _y ) O _{2 -y / 2} } + αCaZrO
₃ (where M is Mg and / or Zn, R is Sc, Y,
A basic component composed of one or more elements selected from Gd, Dy, Ho, Er, Yb, Tb, Tm and Lu), B ₂ O ₃ , SiO ₂ and MO (where MO is B
A dielectric porcelain composition comprising an additional component comprising one or more oxides selected from aO, CaO and SrO) is disclosed.

These dielectric ceramic compositions can be obtained by firing at 1200 ° C. or lower in a non-oxidizing atmosphere, and have a relative dielectric constant of 3000 or more and a resistivity ρ of 1 × 10
⁶ MΩ · cm or more and dielectric loss tan δ is 2.5%
Hereinafter, when the temperature change rate of the relative dielectric constant is −55 ° C. to 125 ° C.,
15% to + 15% (based on 25 ° C), -25 ° C to 85 ° C
Thus, a porcelain capacitor in the range of -10% to + 10% (based on 20 ° C.) can be obtained.

[0009]

In recent years, as electronic circuits have become smaller and more dense, there has been a demand for further reductions in the size and capacitance of laminated ceramic capacitors. As a method of increasing the size and the capacitance of the laminated ceramic capacitor, it is conceivable to reduce the thickness of the dielectric ceramic layer to increase the number of layers. However, if the dielectric ceramic layer is too thin, the insulation resistance of the dielectric ceramic layer is reduced, and the CR product at high temperatures is significantly deteriorated.

An object of the present invention is to provide a low-cost, large-capacity ceramic capacitor having a large CR product at a high temperature.

[0011]

A ceramic capacitor according to the present invention comprises one or more dielectric ceramic layers made of a dielectric ceramic composition, and at least two or more internal layers sandwiching the dielectric ceramic layers. And an electrode, wherein the dielectric porcelain composition comprises 100.0 parts by weight of a basic component;
And 5.0 parts by weight of additional components, wherein the basic components are:
Composition formula (1-α-β) ( Ba k- (x + y) M x L y) O k (Ti 1-z R z) O 2-z / 2 + αCaZrO 3 + βMgNb 2 O 6 ... (1) ( Here, M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
r, Tm, Yb, and Lu), and the additional components are B ₂ O ₃ , SiO _2, and MO (where MO is BaO, Sr
O, CaO, MgO and one or more oxides selected from ZnO).

Here, in the composition formula (1) of the basic component, the value of α is preferably in the range of 0.005 ≦ α ≦ 0.04. When the value of α is within this range, a dense dielectric porcelain composition having desired electrical properties can be obtained. However, when the value of α is less than 0.005, the capacitance changes with temperature. The rate ΔC _-55 is out of the range of −15% to + 15%, ΔC ₋₂₅ is out of the range of −10% to + 10%, α
Exceeds 0.04, the value of ΔC ₈₅ is −10% to + 10%.
This is because the ratio is out of the range of%.

Further, in the composition formula (1) of the basic component,
The value of β is preferably in the range of 0.001 ≦ β ≦ 0.01. When the value of β is within this range, a dense dielectric porcelain composition having desired electrical characteristics can be obtained. However, when the value of β is less than 0.001, the CR product at 150 ° C. Becomes 200 F · Ω or less, the relative dielectric constant ε _s becomes 3300 or less, and when the value of β exceeds 0.01, the CR product at 150 ° C. becomes 200 F · Ω or less and tan δ becomes 2.5 % And the resistivity ρ is 4.0 × 1
0 ⁶ MΩ · cm, the temperature change rate ΔC _{−55 of the} capacitance is out of the range of −15% to + 15%, and ΔC
_-25, since [Delta] C ₈₅ deviates from the range of -10% to +10%.

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 porcelain composition having desired electrical characteristics can be obtained,
When the value of k is less than 1.00, the resistivity ρ becomes 4.00 ×
It becomes smaller than 10 ⁶ MΩ · cm, the temperature change rates ΔC ₋₅₅ and ΔC _{125 of the} capacitance are out of the range of −15% to + 15%, and the ΔC ₋₂₅ and ΔC ₈₅ are in the range of −10% to + 10%. If the value of k exceeds 1.05, the CR product at 150 ° C. becomes 200 F · Ω or less.
This is because a dense sintered body cannot be obtained 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 porcelain 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. When 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%. It is.

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

Incidentally, Mg and Zn of the M component and Ca and Sr of the L component work almost in the same manner, and one or both of Mg and Zn must be used in a range satisfying 0 ≦ x <0.10. In addition, one or both of Ca and Sr can be used in 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 ≦ 0.04. When the value of z is within this range, a dense dielectric porcelain composition having desired electrical properties can be obtained. However, when the value of z is less than 0.002, the resistivity ρ becomes 4.
This is because the CR product becomes smaller than 0 × 10 ⁶ MΩ · cm, the CR product at 150 ° C. becomes 200 F · Ω or less, and when the value of z exceeds 0.04, a dense sintered body cannot be obtained. .

Note that the R components Sc, Y, Gd, Tb, D
y, Ho, Er, Tm, Yb and Lu work almost in the same way, and similar results can be obtained by using one selected from these or by using a combination of two or more.

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

The basic components include Cr ₂ O ₃ , M
One or two or more oxides selected from nO, Fe ₂ O ₃ , CoO, and NiO may be added in trace amounts to enhance sinterability. The amounts of oxides added were Cr, Mn, Fe, Co,
As Ni, 1.0 atomic% or less is preferable. Further, 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 the amount of the added component is set to 100
The reason why the amount is 0.2 to 5.0 parts by weight with respect to the parts by weight of the basic component is that when the amount of the additional component is within this range, a dense dielectric porcelain composition having desired electric characteristics is obtained. However, if the added amount of the additional component is less than 0.2 parts by weight, a dense sintered body cannot be obtained even at 1250 ° C., and the added amount of the additional component is 5.0 parts by weight. If the ratio exceeds the value, the relative dielectric constant ε _s becomes less than 3300, and the temperature change rate ΔC _{−55 of the} capacitance deviates from the range of −15% to + 15%.

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

[0024] The composition of the additive components, thus B ₂ O ₃ -
First to third triangular diagrams showing the composition ratio of SiO ₂ -MO in mol%.
The region surrounded by six straight lines connecting the six points A to F in order is defined as a dense dielectric porcelain composition having desired electrical characteristics, provided that the composition of the additive component is within this region. Can be obtained, but 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. Note that the starting material of the additional component may be another compound such as an oxide or a hydroxide.

Next, a method for manufacturing a ceramic capacitor according to the present invention includes a step of preparing a mixture of unsintered porcelain powder comprising the above-mentioned basic components and additional components, and a step of preparing a non-sintered porcelain sheet comprising the mixture. Forming a laminate in which the unsintered porcelain sheet is sandwiched by at least two or more conductive paste films; baking the laminate in a non-oxidizing atmosphere; Heat-treating the laminate having received it in an oxidizing atmosphere.

Here, the non-oxidizing atmosphere may be not only a reducing atmosphere such as H ₂ or CO, but also a neutral atmosphere such as N ₂ or Ar. Further, the firing temperature in the non-oxidizing atmosphere can be variously changed in consideration of the electrode material.
Heat treatment can be performed at a temperature in the range of 0.050 to 1200 ° C. with almost no aggregation 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 air atmosphere, and for example, an atmosphere having a low oxygen concentration such as a mixture of N ₂ and several ppm of O ₂ can be used. The temperature and oxygen concentration of the atmosphere can be determined by the electrode material (nickel, etc.)
It is necessary to make various changes in consideration of the oxidation of the material and the oxidation of the dielectric ceramic layer. In the embodiment described later, this heat treatment temperature is set to 60.
Although the temperature was set to 0 ° C., the temperature is not limited to this.

In the embodiment described later, the heat treatment in the non-oxidizing atmosphere and the heat treatment in the oxidizing atmosphere are performed in one continuous firing profile. And a heat treatment step in an oxidizing atmosphere can be performed separately.

Although a Zn electrode is used as an external electrode in this embodiment, it is possible to use an electrode of Ni, Ag, Cu or the like by selecting conditions for baking the electrode. It is also possible to apply the coating to the end face of the fired laminated body and simultaneously fire the laminated body and bake the external electrodes.

The contents of the basic components and the contents of the additional components are exactly the same as those of the above-described ceramic capacitor. The present invention is of course also applicable to general single-layer ceramic capacitors other than multilayer ceramic capacitors.

[0031]

First, the case of sample number 1 will be described.
In the case of sample No. 1, the starting material used had a purity of 9
9.0% or more of BaCO ₃ , MgO, ZnO, CaCO
₃ , SrCO ₃ and TiO ₂ powder are prepared, and the composition formula of the basic component is (1−α−β) (Ba _{k− (x + y)} M _x L _y ) O _k (Ti _1−z R _z ) O _{2-z / 2} + αCaZrO ₃ + βMgNb ₂ O ₆ ... (1), (Ba _{k− (x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} ... (2) are formed so that _{(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), were weighed the powder as follows. BaCO ₃ 1029.33 g MgO 6.57 g ZnO 4.42 g CaCO ₃ 5.43 g SrCO ₃ 8.02 g TiO ₂ 425.44 g Er ₂ O ₃ 20.78 g

Next, these powders were ball milled for about 20 minutes.
After wet-mixing for 4 hours, drying at 150 ° C. for 4 hours, and then pulverizing, the pulverized product is calcined in the air at about 1200 ° C. for 2 hours to obtain the basic component having the composition of the first item in the composition formula (1). A powder was obtained.

Next, the second component in the composition formula (1) of the basic component
In order to obtain the term CaZrO ₃ , CaCO ₃ , ZrO ₂
Was weighed as follows. CaCO ₃ 448.21 g ZrO ₂ 551.79 g

Next, these were wet-mixed in a ball mill for about 20 hours, dried at 150 ° C. for 4 hours, and then pulverized, and the pulverized product was calcined in air at about 1250 ° C. for 2 hours to obtain BaZrO ₃ . A powder was obtained.

Next, the third component in the composition formula (1) of the basic component
Term MgNb ₂ O ₆ , MgCO ₃ , Nb ₂
Powder O ₅ were weighed as follows. MgCO ₃ 240.81 g Nb ₂ O ₅ 759.19 g

Next, these were wet-mixed in a ball mill for about 20 hours, dried at 150 ° C. for 4 hours, and then pulverized, and the pulverized product was calcined in air at about 1100 ° C. for 2 hours to obtain MgNb ₂ O. A powder of ₆ was obtained.

Then, in order to obtain the basic component in the case of sample No. 1, 1-α-
β is 0.975 mol, α is 0.02 mol, β is 0.00
Component powder 9 of the first item of the basic component so as to be 5 moles.
7.5 mol parts (977.97 g), 2 mol parts (15.44 g) of the second component powder of the basic component, and 0.5 mol parts (6.59 g) of the third component powder of the basic component Was mixed to obtain 1000 g of a powder of the basic component.

On the other hand, in order to obtain an additive component of sample No. 1, 30.54 g of B ₂ O _3, 52.71 g of SiO ₂ 11.71 g of CaCO ₃ 2.16 g of SrCO ₃ 2.89 g of BaCO ₃ were weighed, and 300 cc of alcohol was added thereto. After stirring for 10 hours using alumina balls in a pot, the mixture was calcined in the atmosphere at 1000 ° C. for 2 hours.
Put into an alumina pot together with 00 cc of alcohol, pulverize with alumina balls for 15 hours, and then dry at 150 ° C. for 4 hours to obtain 30 mol% of B ₂ O _3, 60 mol% of SiO ₂ , and 10 mol% of MO. (CaO: 8 mol%, S
(rO: 1 mol%, BaO: 1 mol%) was obtained as a powder of the additive component.

Next, 1000 g of powder of the basic component (100
10 g (1 part by weight) of the above-mentioned additional component, and an organic binder composed of an aqueous solution of an acrylate polymer, glycerin and a condensed phosphate to the total weight of the basic component and the additional component. Then, 15% by weight was added, and 50% by weight of water was further added. These were put into a ball mill and pulverized and mixed to prepare a slurry of a porcelain raw material. In this example, sintering aids such as Cr ₂ O ₃ and MnO were not added. However, when a sintering aid is added, it is added at this stage.

Next, the slurry is placed in a vacuum defoamer to remove bubbles, and the slurry is placed in a reverse roll coater, which is used to form a thin film based on the slurry on a polyester film. 1 on film
The resultant 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 square for use.

On the other hand, 10 g of nickel powder having an average particle size of 1.5 μm and a solution prepared by dissolving 0.9 g of ethylcellulose in 9.1 g of butyl carbitol were put into 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 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 upward. At this time, the printing surfaces of the adjacent upper and lower sheets were arranged so as to be shifted by about half in the longitudinal direction of the pattern. Furthermore, unprinted green sheets were laminated on each of the upper and lower surfaces of the laminate by 10 sheets each. Next, the laminate was pressed at a temperature of about 50 ° C. by applying a pressure of about 40 tons in the thickness direction. Thereafter, the laminate was cut into a lattice to obtain about 50 laminated chips.

Next, the laminated chip is placed in a furnace capable of firing in an atmosphere, and is heated at a rate of 100 ° C./hr in an air atmosphere.
Heating to 0 ° C. burned the organic binder. Thereafter, the atmosphere of the furnace was changed from the atmosphere to H ₂ (2% by volume) + N ₂ (98%).
(% By volume). Then, while maintaining the furnace in the reducing atmosphere as described above, the heating temperature of the laminated chip is maintained at 600 ° C. to the firing temperature of 1150 ° C. (maximum temperature) for 3 hours, and then the heating is performed at a rate of 100 ° C./hr. C., the atmosphere was replaced with an air atmosphere (oxidizing atmosphere), and the oxidation treatment was performed while maintaining the temperature at 600.degree. C. for 30 minutes.
Then, it was cooled to room temperature to obtain a laminated sintered body chip 15 (see FIG. 1).

Next, the laminated sintered chip 1 from which the electrodes are exposed
5 is coated with a conductive paste composed of zinc, glass frit and vehicle, dried, and dried in air.
Baking at a temperature of 0 ° C. for 15 minutes to form a zinc electrode layer 18, and further, a copper layer 20 is applied thereon by electroless plating,
Further, a Pb—Sn solder layer 22 was provided thereon by electroplating to form a pair of external electrodes 16.

As a result, as shown in FIG. 1, a laminated ceramic capacitor 10 comprising the dielectric ceramic layer 12, the internal electrodes 14, and the external electrodes 16, 16 was obtained. Note that the thickness of the dielectric ceramic layer 12 of the laminated ceramic capacitor 10 is 0.1 mm.
02 mm, opposing area of the internal electrode 14 is 5 mm × 5 mm
= 25 mm ² . The dielectric ceramic layer 12 after sintering
Is substantially the same as the composition of the mixture of the basic component and the additive component before sintering.

Next, when the electrical characteristics of the laminated ceramic capacitor 10 were measured, as shown in Table 3, the relative dielectric constant ε
_s is 3590, tan δ is 1.3%, and resistivity ρ is 5.6.
× 10 ⁶ MΩ · cm, CR product under 150 ° C is 30
The rate of change of the capacitance at −55 ° C. and + 125 ° C. based on the capacitance at 2F · Ω and 25 ° C. is ΔC ₋₅₅ and ΔC ₁₂₅ −
12.9%, -1.1%, Capacitance change at −25 ° C. and + 85 ° C. based on capacitance at 20 ° C. ΔC _-25 , Δ
C ₈₅ is -7.2%, - 6.9%.

The electrical characteristics were measured in the following manner. (A) the relative dielectric constant epsilon _s is the temperature 20 ° C., a frequency 1 kHz, the capacitance under the condition of the voltage (effective value) 1.0 V was measured, the opposing area of the measured value and 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) The 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 was calculated based on the measured value and the dimensions. (D) High temperature CR product (F · Ω) is temperature 150 ℃, frequency 1
The capacitance was measured under the conditions of kHz and a voltage (effective value) of 1.0 V. Thereafter, after applying DC 100 V for 60 seconds, the resistance between the pair of external electrodes was measured, and the capacitance was measured. The value multiplied by the resistance value was calculated. (E) The temperature characteristics of capacitance can be measured by placing a sample in a
55 ° C, -25 ° C, 0 ° C, + 20 ° C, + 25 ° C, +50
The capacitance was measured under the conditions of a frequency of 1 kHz and a voltage (effective value) of 1.0 V at each of the temperatures of ° C, + 85 ° C, + 110 ° C, and + 125 ° C. Of the capacitance at each temperature.

The case of Sample No. 1 has been described above, but also in the case of Samples No. 2 to 91, except that the compositions and proportions of the basic components and the additional components and the firing temperature in a reducing atmosphere were changed. A laminated ceramic capacitor was prepared in exactly the same manner as in the case of Sample No. 1, and its electrical characteristics were measured by the same method.

Tables 1 and 2 show the compositions and proportions of the basic components for each sample, and Tables 2 and 3 show the compositions and proportions of the added components for each sample.
Table 3 shows the firing temperature and the electrical characteristics of the laminated ceramic capacitor for each sample.

The numerical values in the columns x, y, and k in Tables 1 and 2 represent the number of atoms of each element in the composition formula (1) of the basic component described above.
That is, the ratio of the number of atoms of each element when the number of atoms of (Ti + R) is 1 is shown.

Further, in Table 1, Mg and Zn in the column of x are shown.
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.

The amounts of the additional components shown in Table 2 are as follows.
Shown in parts by weight relative to 100 parts by weight of the basic component.
In the column of MO of the added component, BaO, SrO, CaO, M
The proportions of gO and ZnO are shown in mol%. Also,
The amount of the sintering aid to be added is determined based on the molar ratio of Cr, Mn, Fe,
The ratios of o and Ni are shown in atomic%.

In Tables 3 to 5, the temperature characteristics of the capacitances are expressed by ΔC ₋₅₅ (%) and ΔC ₋₅₅ (%) with respect to the capacitance changes at −55 ° C. and + 125 ° C. based on the capacitance at 25 ° C.
C _{12 5} (%), -25 relative to the electrostatic capacitance of 20 ° C.
The rates of change of the capacitances at ° C. and + 85 ° C. are indicated by ΔC _-25 (%) and ΔC ₈₅ (%).

[0054]

[Table 1]

[0055]

[Table 1]

[0056]

[Table 1]

[0057]

[Table 1]

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 2]

[0061]

[Table 2]

[0062]

[Table 2]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 3]

[0066]

[Table 3]

[0067]

[Table 3]

[0068]

[Table 3]

As is apparent from Tables 1, 2 and 3, according to the embodiment of the present invention, the relative dielectric constant ε of the dielectric layer can be reduced by firing at 1200 ° C. or lower in a non-oxidizing atmosphere. _s is 3300 or more and 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 rates ΔC ₋₅₅ and ΔC _{125 of} capacitance are −15% or less.
+ 15% in the range, [Delta] C _-25 and [Delta] C ₈₅ -10% ~ +
It is possible to obtain a laminated ceramic capacitor having an electric characteristic in a range of 10%.

On the other hand, sample numbers 2, 5, 17, and 2
2,23,25-27,30,31,35-37,4
According to the examples of 1, 42, 47, 55 to 59, 75 to 81 and 86, it is not possible to obtain a porcelain capacitor having the electric characteristics aimed at by the present invention. It is outside the scope of the invention.

Table 3 shows the temperature change rate ΔC of the capacitance.
_{Although only −55} , ΔC ₁₂₅ , ΔC _-25 and ΔC ₈₅ are shown, in the embodiment according to the present invention, −25 ° C. to + 85 ° C.
Is in the range of -10% to +1.
0%, and between -55 ° C and +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 Tables 1, 2 and 3. .

First, the appropriate range of the value of α will be examined. When α = 0.005 (sample No. 38), desired electrical characteristics can be obtained, but α = 0 (sample No. 3).
In the case of 7), the temperature change rate ΔC _{−55 of the} capacitance is −1.
It is out of the range of 5% to + 15%, and ΔC- ₂₅ is -10% to
It is out of the range of + 10%. Therefore, the lower limit of α is 0.005.

When α = 0.04 (sample No. 40), desired electrical characteristics can be obtained.
In the case of 0.05 (sample number 41), the temperature change rate ΔC _{-85 of the} capacitance is out of the range of −10% to + 10%. Therefore, the upper limit of α is 0.04.

Next, the appropriate range of the value of β will be examined. When β = 0.001 (sample number 3), desired electrical characteristics can be obtained, but β = 0 (sample number 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 of β is 0.001.

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

Next, the appropriate range of the value of k will be examined. When k = 1.00 (sample No. 32), desired electrical characteristics can be obtained, but when k <1.00 (sample Nos. 30 and 31), the resistivity ρ is 4. 0 × 10 ⁶
It is much smaller than MΩ · cm, the temperature change rates ΔC ₋₅₅ and ΔC _{125 of the} capacitance are out of the range of −15% to + 15%, and the ΔC ₋₂₅ and ΔC ₈₅ are in the range of −10% to + 10%. The CR product at 150 ° C. is significantly smaller than 200 F · Ω. Therefore, the lower limit of k is 1.
00.

When k = 1.05 (sample No. 34), desired electrical characteristics can be obtained.
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 appropriate range of the value of x + y will be examined. When x + y = 0.01 (sample numbers 18 and 19), desired electrical characteristics can be obtained, but x + y = 0.01.
In the case of 0 (sample number 17), the temperature change rate ΔC _{-55 of the} capacitance is out of the range of −15% to + 15%. Therefore, the lower limit of x + y is 0.01.

Further, x + y = 0.10 (sample No. 28,
In the case of (29), desired electrical characteristics can be obtained. However, in the case of x + y = 0.11 (sample numbers 23, 25 and 27), the temperature change rate ΔC _{85 of the} capacitance is −10. % ~ +
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.
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.

Incidentally, Mg and Zn of the M component work almost in the same way, and one or both of Mg and Zn can be used within a range satisfying 0 ≦ x <0.10. Ca and Sr work almost the same, and one or both of Ca and Sr can be used in a range satisfying 0 ≦ y ≦ 0.05. However, regardless of whether one or more of the M component and the L component are used, the value of x + y is
It must be in the range of 0.01 ≦ x + y ≦ 0.10.

Next, the proper range of the value of z will be examined. In the case of z = 0.002 (sample number 43), desired electrical characteristics can be obtained, but z = 0 (sample number 4).
In the case of 2), the resistivity ρ is 4.0 × 10 ⁶ MΩ · cm.
CR product under 150 ℃ is 200F
・ Below Ω. Therefore, the lower limit of z is 0.0
02.

When z = 0.04 (sample No. 46), desired electrical characteristics can be obtained.
In the case of 0.05 (sample number 47), a dense sintered body cannot be obtained by firing at 1250 ° C. Therefore, the upper limit of z is 0.04.

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

Next, the appropriate range of the added amount of the added component will be examined. When the amount of the added component is 0.2 parts by weight (sample number 82) with respect to 100 parts by weight of the basic component,
The desired electrical characteristics can be obtained by firing at 1190 ° C., but in the case of 0 parts by weight (sample number 81), 1250 ° C.
Does not produce a dense sintered body. Therefore, the lower limit of the added amount of the additive component is 0.1 to 100 parts by weight of the basic component.
2 parts by weight.

Further, the amount of the added component was 10%.
In the case of 5.0 parts by weight (sample number 85) with respect to 0 parts by weight, desired electrical characteristics can be obtained, but in the case of 7.0 parts by weight (sample number 86), the relative dielectric constant is obtained. Rate 3300
And the temperature change rate ΔC- _{55 of the} capacitance is −15%
~ 15%. Therefore, the upper limit of the amount of the added component is 5.0 parts by weight based on 100 parts by weight of the basic component.

Next, the composition range of the added component is B ₂ O ₃ −
Triangle diagram showing the composition ratio of SiO ₂ -MO in mol% (FIG. 2)
Are in a range surrounded by six straight lines connecting the first to sixth points A to E in order. The first point A in the triangular diagram is B ₂ O ₃
Is 1 mol%, SiO ₂ is 80 mol%, MO is 19 mol%
(Sample No. 65), the second point B being B ₂ O ₃
Is 1 mol%, SiO ₂ is 39 mol%, MO is 60 mol% (sample No. 66), and the third point C is B ₂
The composition has a composition of 29 mol% of O _3, 1 mol% of SiO ₂ , and 70 mol% of MO (sample No. 67).
A composition of 90 mol% of ₂ O _3, 1 mol% of SiO ₂ , and 9 mol% of MO (sample No. 68) is shown.
The composition of 90 mol% of ₂ O ₃ , 9 mol% of SiO ₂ , and 1 mol% of MO (sample No. 69) is shown.
19 mol% of ₂ O _3, 80 mol% of SiO ₂ , MO of 1
It shows the composition of mol% (sample No. 70).

The composition range of the additive component is B ₂ O ₃ —SiO
_{The first} in a triangular diagram (FIG. 2) showing the composition ratio of _2- MO in mol%.
The desired electrical characteristics can be obtained within a range surrounded by six straight lines connecting the points A to F in order (sample numbers 65 to 74). If it is outside the above range (sample numbers 75 to 80), a dense sintered body cannot be obtained by firing at 1250 ° C.

As shown in the case of sample numbers 87 to 91, the MO components were 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 addition amounts of Co and Ni are 1.0 atomic% (sample no.
64), desired electrical characteristics can be obtained. However, in the case of 1.5 atomic% (sample numbers 55 to 59),
The relative dielectric constant ε _s becomes 3300 or less. Therefore,
The addition amount of the sintering aid is preferably 1.0 atomic% or less.

[0092]

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 −15% to + 15% at −55 ° C. to 125 ° C. (25
° C), -10% to + 10% at -25 ° C to 85 ° C
It is possible to provide a porcelain capacitor in the range (based on 20 ° C.).

[Brief description of the drawings]

FIG. 1 is a sectional view of a multilayer 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 constituting a dielectric layer of the ceramic capacitor according to the present invention.

[Explanation of symbols]

 Reference Signs List 12 dielectric ceramic layer 14 internal electrode 15 laminated sintered 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 1 ○ 5]

[Table 2 ○ 1]

[Table 2 ○ 2]

[Table 2 ○ 3]

[Table 2 ○ 4]

[Table 2 ○ 5]

[Table 3 ○ 1]

[Table 3 ○ 2]

[Table 3 ○ 3]

[Table 3 ○ 4]

[Table 3 ○ 5]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kishi 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Yuden Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H01G 4/12

Claims (4)

(57) [Claims] 1. A porcelain capacitor comprising one or more dielectric porcelain layers made of a dielectric porcelain composition and at least two or more internal electrodes sandwiching said dielectric porcelain layer, The porcelain composition comprises a mixture obtained by calcining a mixture of 100.0 parts by weight of a basic component and 0.2 to 5.0 parts by weight of an additional component, wherein the basic component has a composition formula (1-α-β ) (Ba _{k- (x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} + αCa
ZrO ₃ + βMgNb ₂ O ₆ (where M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
One, two or more elements selected from r, Tm, Yb and Lu, α, β, k, x, y and z are 0.005 ≦ α ≦ 0.04 0.001 ≦ β ≦ 0. 01 1.00 ≦ k ≦ 1.05 0 ≦ x <0.10 0 ≦ y ≦ 0.05 0.01 ≦ x + y ≦ 0.10 0.002 ≦ z ≦ 0.04) Wherein the additional components are B ₂ O ₃ , SiO ₂ and MO (where 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 such that these compositions are In the triangular diagram shown in mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
A first point A where the MO has a composition of 19 mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 39 mol%,
A second point B having a composition in which the MO is 60 mol%, the B ₂ O ₃ is 29 mol%, the SiO ₂ is 1 mol%,
A third point C having a composition of 70 mol% of MO, 90 mol% of B ₂ O ₃ , 1 mol% of SiO ₂ ,
A fourth point D indicating a composition of 9 mol% of MO, 90 mol% of B ₂ O ₃ , 9 mol% of SiO ₂ ,
A fifth point E indicating the composition of the MO of 1 mol%, and a sixth point F indicating the composition of the B ₂ O ₃ of 19 mol%, the SiO ₂ of 80 mol%, and the MO of 1 mol%. In a region surrounded by six straight lines connecting in this order. 2. Cr, Mn, F in a dielectric porcelain composition.
2. The porcelain capacitor according to claim 1, 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. 3. A step of preparing a mixture comprising unsintered porcelain powder; a step of forming a non-sintered porcelain sheet comprising the mixture; and a step of forming the unsintered porcelain sheet into at least two or more conductive paste films. Forming a laminate sandwiched between, and baking the laminate in a non-oxidizing atmosphere, and heat-treating the fired laminate in an oxidizing atmosphere, A mixture comprising unsintered porcelain powder is composed of 100.0 parts by weight of a basic component and 0.2 to 5 parts by weight of an additional component, wherein the basic component has a composition formula (1−α−β) ( Ba _{k- (x + y)} M _x L _y ) O _k (Ti _1-z R _z ) O _{2-z / 2} + αCa
ZrO ₃ + βMgNb ₂ O ₆ (where M is Mg and / or Zn, L is Ca and / or Sr, R is Sc, Y, Gd, Tb, Dy, Ho, E
One, two or more elements selected from r, Tm, Yb and Lu, α, β, k, x, y and z are 0.005 ≦ α ≦ 0.04 0.001 ≦ β ≦ 0. 01 1.00 ≦ k ≦ 1.05 0 ≦ x <0.10 0 ≦ y ≦ 0.05 0.01 ≦ x + y ≦ 0.10 0.002 ≦ z ≦ 0.04) Wherein the additional components are B ₂ O ₃ , SiO ₂ and MO (where 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 such that these compositions are In the triangular diagram shown in mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
A first point A where the MO has a composition of 19 mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 39 mol%,
A second point B having a composition in which the MO is 60 mol%, the B ₂ O ₃ is 29 mol%, the SiO ₂ is 1 mol%,
A third point C having a composition of 70 mol% of MO, 90 mol% of B ₂ O ₃ , 1 mol% of SiO ₂ ,
A fourth point D indicating a composition of 9 mol% of MO, 90 mol% of B ₂ O ₃ , 9 mol% of SiO ₂ ,
A fifth point E indicating the composition of the MO of 1 mol%, and a sixth point F indicating the composition of the B ₂ O ₃ of 19 mol%, the SiO ₂ of 80 mol%, and the MO of 1 mol%. Characterized by being in a region surrounded by six straight lines connecting these in this order. 4. The method according to claim 1, wherein Cr, Mn, and F are contained in the dielectric ceramic composition.
4. The method 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.