JPH0526323B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a ceramic capacitor having a single-layer or laminated structure consisting of dielectric ceramic and at least two electrodes, and a method for manufacturing the same. [Conventional technology] Conventionally, when manufacturing multilayer ceramic capacitors,
A conductive paste of noble metals such as platinum or palladium is printed in a desired pattern on a green sheet (unsintered porcelain sheet) made of dielectric porcelain raw material powder, multiple sheets are stacked and pressed together, and oxidized at 1300°C to 1600°C. sintered in a neutral atmosphere. Thereby, the dielectric ceramic and the internal electrode can be obtained at the same time. As mentioned above, if a noble metal is used, the intended internal electrode can be obtained even if it is sintered at high temperature in an oxidizing atmosphere. However, since precious metals such as platinum and palladium are expensive, the cost of multilayer ceramic capacitors has inevitably increased. As a solution to the above-mentioned problem, Japanese Patent Publication No. 14607/1987, filed by the applicant _, states that ( _{Bakx Mx} ) _OkTiO2 (where M is at least one of Mg and Zn). basic ingredients consisting of seeds);
A dielectric ceramic composition is disclosed that includes an additive component consisting of LiO ₂ and SiO ₂ . In addition, in Japanese Patent Publication No. 61-14608, instead of Li ₂ O and SiO ₂ in the above-mentioned Japanese Patent Publication No. 61-14607,
Li ₂ O, SiO ₂ and MO (however, MO is BaO, CaO and
A dielectric ceramic composition containing an additive component consisting of at least one type of SrO is disclosed. In addition, in Special Publication No. 6-14609, (Ba _kxy
M _x L _y ) O _k TiO ₂ (M is at least one of Mg and Zn, L is at least one of Sr and Ca)
A dielectric ceramic composition is disclosed that includes a basic component consisting of Li ₂ O and an additive component consisting of Li 2 O and Si ₂ . In addition, in Japanese Patent Publication No. 61-14610, instead of Li ₂ O and SiO ₂ in the above-mentioned Japanese Patent Publication No. 61-14609, Li ₂ O, SiO ₂ and MO (however, MO is BaO, CaO
and at least one of SrO) is disclosed. In addition, in Special Publication No. 61-14611, (Ba _kx
M _x )O _k TiO ₂ (where M is at least one of Mg, Zn, Sr, and Ca) and B _{2 O}
A dielectric ceramic composition is disclosed that includes an additive component consisting of SiO ₂ . In addition, in Special Publication No. 1595/1983, (Ba _kx M _x )
A basic component consisting of O _k TiO ₂ (where M is at least one of Mg, Zn, Sr, and Ca), and B ₂ O ₃ .
MO (However, MO is BaO, MgO, ZnO, SrO and
A dielectric ceramic composition is disclosed that includes an additive component consisting of at least one type of CaO. In addition, in Japanese Patent Publication No. 62-1596, instead of B ₂ O ₃ and MO in the above-mentioned Japanese Patent Publication No. 62-1595, B ₂ O ₃
and SiO ₂ and MO (however, MO is BaO, MgO, ZnO,
A dielectric ceramic composition is disclosed that includes an additive component consisting of at least one of SrO and CaO. The dielectric ceramic compositions disclosed in these are:
It can be obtained by firing in a reducing atmosphere of 1200℃ or less, has a dielectric constant of 2000 or more, and can have a temperature change rate of capacitance of ±10% from -25℃ to +85℃. be. [Problem to be solved by the invention] By the way, with the recent increase in the density of electronic circuits,
There is a strong demand for miniaturization of multilayer capacitors, and in order to meet this demand, we have improved the non-permittivity of the dielectric material to the ratio of the dielectric ceramic compositions disclosed in the above publications without worsening the rate of temperature change. It is desired to further increase the dielectric constant. Therefore, the purpose of the present invention is to provide a non-oxidizing atmosphere,
Porcelain capacitors equipped with dielectric porcelain that has a high dielectric constant and a small rate of change in dielectric constant over a wide temperature range, even though it is obtained by firing at a temperature of 1200°C or lower. The object of the present invention is to provide a manufacturing method thereof. [Means for Solving the Problems] To achieve the above object, the present invention provides a ceramic capacitor comprising a dielectric ceramic and at least two electrodes in contact with the ceramic, in which the ceramic is 100.0 parts by weight. It consists of a basic component and 0.2 to 5.0 parts by weight of additional components, and the basic component is (1-α)
_{{ Ba kx M _ _ _} 1 type of metal, R
are Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tm,
At least one metal of Lu, α, k, x,
z, 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 additive components are B ₂ O ₃ , SiO ₂ and MO (however, MO is BaO,
At least one of SrO, CaO, MgO and ZnO
and the composition range of the B ₂ O ₃ , the SiO ₂ and the MO is 1 mol % of the B ₂ O ₃ in the triangular diagram showing these compositions in mol %, A point (A) where SiO ₂ is 80 mol% and the MO is 19 mol%, and a point (B) where the B ₂ O ₃ is 1 mol%, the SiO ₂ is 39 mol%, and the MO is 60 mol%. , said B ₂ O ₃
is 30 mol%, the SiO ₂ is 0 mol%, and the MO is 70 mol%.
Point (C) of mol %, the above B ₂ O ₃ is 90 mol %, the above
A point (D) where SiO ₂ is 0 mol % and the MO is 10 mol %,
A point ( _E ) where the B ₂ O ₃ is 90 mol %, _the SiO ₂ is 10 mol _% , and the MO is 0 mol %; This relates to a capacitor within a region surrounded by six straight lines sequentially connecting the point (F) where MO is 0 mol %. In addition, in the composition formula showing the basic components, k-x-
z, x, z, k, 1-y, y, 2-y/2 of course indicate the number of atoms of each element, and (1-α) and α
is the first term of the composition formula (Ba _kxz M _x L _z )O _k (Ti _1-y
R _y ) indicates the ratio of O _2-y/2 and the second term CaZrO ₃ in moles, where Ba is barium, O is oxygen, and Ti
is titanium, Mg is magnesium, Zn is zinc, Ca is calcium, and Sr is strontium. Also,
Sc is scandium, Y is yttrium, Gd is gadolinium, Dy is dysprosium, Ho is holonium, Er is erbium, Yb is iterbium, Tb
is terbium, Tm is thulium, and Lu is lutetium. B ₂ O ₃ in the additive component is boron oxide,
SiO ₂ is silicon oxide, BaO is barium oxide, SrO is strontium oxide, CaO is calcium oxide,
MgO is magnesium oxide and ZnO is zinc oxide. The invention related to the manufacturing method includes the steps of: preparing a mixture of the above-mentioned basic components and additive components; making a molded product of the mixture having at least two electrode parts; and non-containing the molded product having the electrode parts. The present invention relates to a method for manufacturing a ceramic capacitor, which includes a step of firing in an oxidizing atmosphere and a step of heat-treating a molded product obtained by the firing in an oxidizing atmosphere. [Operation and Effect] The dielectric ceramic in the ceramic capacitor of the above invention can be obtained by firing in a non-oxidizing atmosphere at 1200°C or lower. Therefore, it becomes 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 simultaneously. By setting the composition of the dielectric ceramic within the range specified in the present invention, the relative dielectric constant is 3000 or more, the dielectric loss tan δ is 2.5% or less, and the resistivity ρ is 1×
10 ⁶ MΩ・cm or more, and the temperature change rate of relative permittivity is -15% to +15% (based on 25°C) from -55°C to 125°C, and -10% to +10 from -25°C to 85°C. % (based on 20°C), we can provide capacitors with dielectric ceramics that fall within the range of 20℃. [Examples] Next, Examples and Comparative Examples according to the present invention will be described. First, the compositional formula of the basic components according to the present invention (1-α) {(Ba _kxz M _x L _z )O _k (Ti _1-y R _y )
(Ba _kxz M _x L _z )O _k (Ti _1-y R _y ) of the first term in O _{2-y/2 }} +αCaZrO 3
O _2-y/2 (hereinafter referred to as the first basic component) is k-x-z, x, z, x+ of sample No. 1 in Tables 1 and 2.
In other words, (Ba _0.96 M _0.04 L _0.02 ) O _1.02 (Ti _0.99 R _0.01 ) O _1.995
,
More specifically, M _0.04 = Mg _0.02 Zn _0.02 , L _0.02 =
Since Ca _0.01 Sr _0.01 and R _0.01 = Yb _0.01 , (Ba _0.96
Mg _0.02 Zn _0.02 Ca _0.01 Sr _0.01 ) O _1.02 (Ti _0.99 Yb _0.01 )
_BaCO3 (barium carbonate), MgO (magnesium oxide), ZnO with a purity of 99.0% or more to obtain O _1.995
(zinc oxide), CaO (calcium oxide), SrO (stmentium oxide) and TiO ₂ (titanium oxide),
Prepare Yb ₂ O ₃ (ytterbium oxide) and add it without adding any impurities _. Equivalent) CaO: 3.08 g (equivalent to 0.01 mole part) SrO: 5.70 g (equivalent to 0.01 mole part) TiO ₂ : 435.06 g (equivalent to 0.99 mole part) Yb ₂ O ₃ : 10.84 g (equivalent to 0.005 mole part) were weighed. Next, put these weighed raw materials into a pot mill, add an alumina ball and 2.5 ml of water.
After wet stirring for 15 hours, the stirred material was placed in a stainless steel pot and heated to 150℃ in a hot air dryer.
It was dried for 4 hours. Next, this dried material is coarsely pulverized, and the coarsely pulverized material is heated in a tunnel furnace at 1200°C in the atmosphere for 20 minutes.
The product was calcined for a period of time to obtain the first basic component having the above compositional formula. In addition, in order to obtain CaZrO ₃ (hereinafter referred to as the second basic component) in the second term of the composition formula of the basic component,
Weighed 448.96 g of the former and 551.04 g of the latter so that CaCO ₃ (calcium carbonate) and ZrO ₂ (zirconium oxide) were equimolar, mixed them, dried them, and crushed them, resulting in approximately 1250 g of ZrO 2 (zirconium oxide). It was calcined in air at ℃ for 2 hours. Next, as shown in sample No. 1 in Table 1, 1−α
98 mol parts (984.34 g) of the first basic component (Ba _0.96 Mg _0.02
A powder of Zn _0.02 Ca _0.01 Sr _0.01 ) O _1.02 (Ti _0.99 Yb _0.01 ) O _1.995 and 2 mole parts (15.66 g) of a powder of the second basic component (CaZrO ₃ ) were mixed to obtain 1000 g of the basic component. Ta. On the other hand, in order to obtain the additive components of sample No. 1 in Table 3, 1.03 g (1 mol) of B ₂ O ₃ and 70.57 g of SiO ₂ were added.
(80 mol parts) and 11.03 g (3.8 mol parts) of BaCO ₃
, 13.99 g (9.5 mole parts) of CaCO ₃ and MgO
3.38 g (5.7 mole parts) of each were weighed, 300 c.c. of alcohol was added to this mixture, stirred in a polyethylene pot using an alumina ball for 10 hours, and then pre-calcined in the air at 1000°C for 2 hours. this
The alumina balls were placed in an alumina pot with 300 c.c. of water, ground for 15 hours, and then dried at 150°C for 4 hours to form a mixture of 1 mol% B ₂ O ₃ and 80 mol% SiO ₂ .
MO is 19 mol% (BaO3.8 mol% + CaO9.5 mol%
An additive component powder having a composition of 5.7 mol %) was obtained. In addition, the contents of MO, BaO, CaO, and MgO
As shown in Table 3, the proportions are 20 mol%, 50 mol%, and 30 mol%. Next, 2 parts by weight (20 g) of additive components are added to 100 parts by weight (1000 g) of the basic component, and an organic binder consisting of an aqueous solution of acrylic acid ester polymer, glycerin, and condensed phosphate is added to the basic component. A slurry of porcelain raw material was prepared by adding 15% by weight based on the total weight of the ingredients, and further adding 50% by weight of water, and placing them in a ball mill to grind and mix. 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 received on a long polyester film, and the film is coated on the same film. Then heat this to 100℃ and dry it.
A green porcelain sheet with a thickness of about 25 μm was obtained. This sheet is long, but it is cut into 10cm squares. On the other hand, the conductive paste for internal electrodes has an average particle size of
10g of 1.5μm nickel powder and ethyl cellulose
A solution of 0.9 g dissolved in 9.1 g of butyl carbitol was placed in a stirrer and stirred for 10 hours. This conductive paste was printed on one side of the unsintered porcelain sheet through a screen having 50 patterns of 14 mm in length and 7 mm in width, and then dried. Next, two unsintered porcelain sheets were laminated with the printed surfaces facing up. At this time, the adjacent upper and lower sheets were arranged so that their printed surfaces were shifted by about half in the longitudinal direction of the pattern. Further, four unset porcelain sheets each having a thickness of 60 μm were laminated on the upper and lower surfaces of this laminate. This laminate is then approximately
A load of approximately 40 tons was applied in the thickness direction at a temperature of 50°C to bond the material. Thereafter, this laminate was cut into a grid shape to obtain 50 laminate chips. Next, this laminate was placed in a furnace capable of firing in an atmosphere, and the temperature was raised to 600° C. at a rate of 100° C./h in an air atmosphere to burn the organic binder. After that, the atmosphere of the furnace is changed from the atmosphere to H ₂ (2% by volume) + N ₂
(98% by volume). Then, while maintaining the reducing atmosphere in the furnace as described above, the heating temperature for lamination was increased from 600°C to the sintering temperature of 1130°C.
Raise the temperature at a rate of 100℃/h to 1130℃ (maximum temperature)
After holding for 3 hours, the temperature was lowered to 600°C at a rate of 100°C/h, and the atmosphere was changed to air (oxidizing atmosphere).
Instead, oxidation treatment was performed by holding the temperature at 600°C for 30 minutes, and then cooling to room temperature to produce a laminated sintered chip. Next, in order to obtain the multilayer ceramic capacitor 10 shown in FIG. 1, a pair of external electrodes 16 were formed on a multilayer sintered chip 15 consisting of three dielectric ceramic layers 12 and two internal electrodes 14. In addition, external electrode 1
In step 6, a conductive paste consisting of zinc, glass frit, and vehicle is applied to the side surface of the sintered chip 15 where the electrodes are exposed, dried, and then heated in the atmosphere at a temperature of 550°C. A zinc electrode layer 18 is formed by baking for 15 minutes, a copper layer 20 is formed thereon by electroless plating, and a Pb-Sn solder layer 22 is further formed on this by electroplating. The thickness of the dielectric ceramic layer 12 of this capacitor 10 is 0.02 mm, and the opposing area of a pair of internal electrodes 14 is 5 mm.
×5mm= ^25mm2 . Note that the porcelain layer 12 after sintering
The composition of is substantially the same as the mixed composition of the basic components and additive components before sintering. Next, measure the electrical characteristics of the capacitor 10,
When the average value was calculated, as shown in Table 3,
The relative dielectric constant ε _s is 3700, tan δ is 1.1%, and the resistivity ρ is
3.8×10 ⁶ MΩ・cm, capacitance change rate ΔC _-55 at -55℃ and +125℃ based on capacitance at 25℃,
ΔC ₁₂₅ is -10.2%, +4.3%, capacitance change rate ΔC _-25 at -25℃ and +85℃ based on capacitance at 20℃, ΔC ₈₅ is -7.1%, -3.6%. It was hot. Note that the electrical characteristics were measured in the following manner. (A) The relative permittivity ε _s is determined by measuring the capacitance under the conditions of temperature 20°C, frequency 1kHz, and voltage (effective value) 1.0V, and the measured value is calculated using the opposing area of 25 mm ² of the pair of internal electrodes 14 and the pair of Thickness of porcelain layer 12 between internal electrodes 14: 0.02
Calculated from mm. (B) Dielectric loss tan δ (%) was measured under the same conditions as the relative dielectric constant. (C) Resistivity ρ (MΩ・cm) at a temperature of 20℃
After applying DC 100V for 1 minute, the resistance value between the pair of external electrodes 16 was measured, and calculated based on this measured value and the dimensions. (D) Temperature characteristics of capacitance are measured by placing the sample in a thermostatic chamber and measuring the temperature at -55℃, -25℃, 0℃, +20℃, +40℃, +
Capacitance was measured at each temperature of 60℃, +85℃, +105℃, and +125℃ under the conditions of frequency 1kHz and voltage (effective value) 1.0V, and the capacitance at each temperature at 20℃ and 25℃ was measured. It was obtained by finding the rate of change in . The preparation method and characteristics of sample No. 1 have been described above, but for samples No. 2 to 126, the composition of the basic components and additive components, their ratios, and the firing temperature in a reducing atmosphere were A multilayer ceramic capacitor was produced in exactly the same manner as Sample No. 1, except for the changes shown in Tables 4 to 4, and its electrical characteristics were measured in the same manner. Table 1 shows (1-α), α, k-x-z, x, z, and x+z in the compositional formula showing the basic components, and Mg and Zn in the x column are the contents of M in the general formula. The numbers of these atoms are shown in the Mg and Zn columns, the total value (x value) of these is shown in the total column, and Ca and Sr in the z column are the numbers of L in the general formula. indicate the content,
The Ca and Sr columns show the numbers of these atoms, and the total column shows their total value (z value). Table 2 shows the content and amount of R and the value of k in the compositional formula showing the basic components. In other words, Se, Y, Gd, Dy, Ho, Er, and Yb in the y column indicate the contents of R in the general formula, the numbers of these atoms are shown in these columns, and these are shown in the total column. etc. total value (y value)
It is shown. Table 3 shows the amounts and compositions of the additive components for each sample. The amount of the additive component added is shown in parts by weight based on 100 parts by weight of the basic component.
In Table 3, the MO content column for additive components includes BaO,
The proportions of MgO, ZnO, SrO, and CaO are shown in mol%. Table 4 shows the firing temperature and electrical properties of each sample. In this Table 4, the temperature characteristics of capacitance are -55℃ and +125℃ based on 25℃ capacitance.
Capacitance change rate in °C ΔC _-55 (%) and ΔC ₁₂₅ (%)
and -25℃ and +85℃ based on 20℃ capacitance
The rate of change in capacitance is expressed as ΔC _-25 (%) and ΔC ₈₅ (%).

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[Table] As is clear from Tables 1 to 4, the samples according to the present invention have a dielectric constant ε _s of 3000 or more and a dielectric loss tan δ when fired in a non-oxidizing atmosphere at 1200°C or lower.
2.5% or less, resistivity ρ is 1×10 ⁶ MΩ・cm or more, temperature change rate of capacitance ΔC _-55 and ΔC ₁₂₅ is -15% ~
+15%, ΔC _-25 and ΔC ₈₅ are in the range of -10% to +10%, making it possible to obtain a capacitor with desired characteristics. On the other hand, sample Nos. 11 to 13, 38, 43, 44, 49, 50,
54, 55, 59, 60, 68-71, 77, 81, 82, 86, 91,
94, 97, 100, 103, 106, 109, 114, and 126 cannot achieve the object of the present invention. Therefore, these are outside the scope of the present invention. Although only ΔC _-55 , ΔC ₁₂₅ , ΔC _-25 and ΔC ₈₅ are shown in Table 4, various electrostatic charges in the range of -25°C to +85°C for samples belonging to the scope of the present invention are shown. The rate of change ΔC falls within the range of -10% to +10%, and -
The various capacitance change rates ΔC in the range of 55° C. to +125° C. are in the range of −15% to +15%. Next, the reasons for limiting the composition will be described. When the value of x+z is zero, as shown in sample No. 60, ΔC _-25 is outside the range of -10% to +10%, but as shown in sample Nos. 61, 62, and 63, the value of x+z value
In the case of 0.01, desired electrical characteristics can be obtained. Therefore, the lower limit of the value of x+z is 0.01. On the other hand, as shown in sample No. 69 and 70, when the value of x+z is 0.12, ΔC ₈₅ is outside the range of -10% to +10%, but as shown in sample No. 76, when the value of x+z is
In the case of 0.10, desired electrical characteristics can be obtained. However, as shown in sample Nos. 68 and 71, even if the value of x+z is 0.07, if the value of z exceeds 0.05, the 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 z must be 0.05. In addition, Mg and Zn of the M component and Ca and Sr of the L component work almost in the same way, and one or both of Mg and Zn should be used within the range that satisfies 0<x<0.10, and 0<z≦
One or both of Ca and Sr can be used within a range that satisfies 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. The value of y is sample No. 91, 94, 97, 100, 103, 106,
As shown in samples No. 109, 114, and 126, a dense sintered body cannot be obtained in the case of 0.06, but sample Nos. 90, 93, 96,
99, 102, 105, 108 etc., the value of y is 0.04
In this case, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of y is 0.04. In addition,
The R components Sc, Y, Dy, Ho, Er, and Yb work almost in the same way, and the same result can be obtained even if one selected from these or a plurality of them are used. In addition, it is desirable that the value of y be in the range of 0.04 or less, regardless of whether there is one type of R component or multiple types of R components. Also, if y is 0.04 or less, 0
Even small amounts close to 100% have certain effects. Note that the component represented by R in the compositional formula contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, it becomes possible to easily keep the temperature change rate of capacitance ΔC _-55 to ΔC ₁₂₅ in the range of -55°C to 125°C within the range of -15% to +15%. with -25℃~85℃
Temperature change rate of capacitance in the range ΔC _-25 to _{ΔC 85} −
It becomes possible to easily keep the capacitance within the range of 10% to +10%, and the fluctuation width of the temperature change rate of capacitance in each temperature range can be made small. Also,
The R component has the function of increasing the resistivity ρ and the function of increasing sinterability. If the value of α is zero, as shown in samples No. 50 and 55, ΔC _-25 will be outside the range of -10% to +10%, and ΔC _-55 will be outside the range of -15% to +15%. , Sample No. 51, 56
As shown in the figure, when the value of α is 0.005, desired electrical characteristics can be obtained. Therefore, the lower limit of the value of α is 0.05. On the other hand, when the value of α is 0.05 as shown in samples No. 54 and 59, ΔC ₈₅ varies from −10% to +
Although it is outside the range of 10%, desired electrical characteristics can be obtained when the value of α is 0.04, as shown in Sample Nos. 53 and 58. Therefore, the upper limit of the value of α is 0.04
It is. When the value of k is smaller than 1.0, as shown in Samples No. 77 and 82, ρ becomes less than 1×10 ⁶ MΩ・cm, which is significantly lower, but as shown in Samples No. 78 and 83, , k is 1.00, desired electrical characteristics can be obtained. Therefore, the lower limit of the value of k is 1.00. On the other hand, the value of k is as shown in sample Nos. 81 and 86,
When the value of k is greater than 1.05, a dense sintered body cannot be obtained, but as shown in sample Nos. 80 and 85, when the value of k is 1.05, desired electrical characteristics can be obtained. Therefore,
The upper limit of the value of k is 1.05. If the amount of additive components added is zero, sample No. 38,
As is clear from No. 44, a dense sintered body cannot be obtained even when the firing temperature is 1250°C, but as shown in Samples No. 39 and 45, the addition amount is 0.2 parts by weight per 100 parts by weight of the basic component. In this case, a sintered body with desired electrical properties can be obtained by firing at 1170°C. Therefore,
The lower limit of additive components is 0.2 parts by weight. On the other hand, the sample
As shown in Nos. 43 and 49, when the amount of the additive component is 7.0 parts by weight, ε _s is less than 300, and ΔC ₈₅
is outside the range of -10% to +10%, or ΔC _-55
is outside the range of -15% to -15%, but sample No. 42,
As shown in No. 48, when the amount added is 5.0 parts by weight, desired characteristics can be obtained. Therefore, the upper limit of the amount added is 5.0 parts by weight. The preferred composition of the additive components is B ₂ O ₃ − in FIG.
It can be determined based on a triangular diagram showing the composition ratio of SiO ₂ -MO. The first point (A) in the triangular diagram is the sample
No. 1 B ₂ O ₃ is 1 mol%, SiO ₂ is 80 mol%, MO
shows a composition of 19 mol%, and the second point (B) is sample No.
B ₂ O ₃ of 2 is 1 mol%, SiO ₂ is 39 mol%, MO is
It shows a composition of 60 mol%, and the third point (C) is sample No. 3.
B ₂ O ₃ of 30 mol %, SiO ₂ 0 mol %, MO 70
The composition in mol% is shown, and the fourth point (D) is the composition of sample No. 4.
It shows a composition of 90 mol% B ₂ O ₃ , 0 mol% SiO ₂ , and 10 mol% MO, and the fifth point (E) is that of sample No. 5.
It shows a composition of 90 mol% B ₂ O ₃ , 10 mol% SiO ₂ , and 0 mol% MO, and the sixth point (F) is the same as that of sample No. 6.
_The composition is 20 mol% _B2O3 , 80 mol% _SiO2 , and 0 mol% MO. The composition of the additive components of the sample that falls within the scope of the present invention is within the region surrounded by six straight lines connecting points 1 to 6 (A) to (F) in the triangular diagram in order. If the composition is within this range, desired electrical characteristics can be obtained. On the other hand, if the composition of the additive components falls outside the range specified in the present invention, as in Samples No. 11 to 13,
A dense sintered body cannot be obtained. In addition, M.O.
The components include BaO, as shown in samples No. 14 to 18, for example.
It may be any one of MgO, ZnO, SrO, CaO, or an appropriate ratio as shown in other samples. [Modifications] Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and, for example, the following modifications are possible. (a) A trace amount of a mineralizing agent such as MnO ₂ (preferably 0.05 to 0.1% by weight) may be added to the basic components to improve the sinterability, within a range that does not impede the object of the present invention. Further, other substances may be added as necessary. (b) The starting materials may be oxides or hydroxides or other compounds other than those shown in the examples. (c) The temperature of the treatment in the oxidizing atmosphere after the treatment in the non-oxidizing atmosphere during firing is lower than the sintering temperature other than 600℃ (preferably 500℃ to 1000℃).
range). That is, various changes can be made in consideration of the electrode material such as nickel and the oxidation of porcelain. (d) The firing temperature in a non-oxidizing atmosphere can be varied depending on the electrode material. When nickel is used as the internal electrode, almost no aggregation of nickel particles occurs in the range of 1050°C to 1200°C. (e) Sintering may be performed in a neutral atmosphere. (f) It is of course applicable to general single-layer ceramic capacitors other than multilayer ceramic capacitors. (g) Tb, Tm, Lu in the R component in the composition formula
Although it is not particularly listed in Tables 1 to 4, it has been confirmed that it can be used in the same way as the other R components.

[Brief explanation of the drawing]

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

Claims (1)

[Scope of Claims] 1. A ceramic capacitor comprising dielectric ceramic and at least two electrodes in contact with the ceramic, wherein the ceramic comprises 100.0 parts by weight of a basic component and 0.2 to 5.0 parts by weight of an additive component. The basic component is (1-α) {(Ba _kxz M _x L _z )O _k (Ti _1-y R _y )
O _2-y/2 }+αCaZrO ₃ (M is at least one metal among Mg and Zn, L is at least one metal among Ca and Sr,
R is Sc, Y, Gd, Dy, Ho, Er, Yb, Tb,
Tm, at least one metal among Lu, α, k,
x, z, y are numerical values satisfying the following: 0.005≦α≦0.04 1.00≦k≦1.05 0<x<0.10 0<1≦0.05 0.01≦x+z≦0.10 0<y≦0.04), and the additive component is B ₂ O ₃ and SiO ₂ and MO (however, MO
consists of at least one metal oxide of BaO, SrO, CaO, MgO and ZnO), and
The composition ranges of B ₂ O ₃ , the SiO ₂ and the MO are shown in a triangular diagram showing these compositions in mol%. The B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
Point (A) where the MO is 19 mol %, the B ₂ O ₃ is 1 mol %, the SiO ₂ is 39 mol %,
Point (B) where the MO is 60 mol%, the B ₂ O ₃ is 30 mol%, the SiO ₂ is 0 mol%,
Point (C) where the MO is 70 mol %, the B ₂ O ₃ is 90 mol %, the SiO ₂ is 0 mol %,
Point (D) where the MO is 10 mol%, the B ₂ O ₃ is 90 mol%, the SiO ₂ is 10 mol%,
Point (E) where the MO is 0 mol%, the B ₂ O ₃ is 20 mol%, the SiO ₂ is 80 mol%,
A capacitor characterized in that the MO is within a region surrounded by six straight lines sequentially connecting points (F) with 0 mol %. 2 Consists of 100.0 parts by weight of the basic component and 0.2 to 5.0 parts by weight of additional components, and the basic component is (1-α) {(Ba _kxz M _x L _z )O _k (Ti _1-y R _y )
O _2-y/2 }+αCaZrO ₃ (M is at least one metal among Mg and Zn, L is at least one metal among Ca and Sr,
R is Sc, Y, Gd, Dy, Ho, Er, Yb, Tb,
Tm, at least one metal among Lu, α, k,
x, z, y are 0.005≦α≦0.04, 1.00≦k≦
1.05, 0<x<0.10, 0<1≦0.05, 0.01≦x+
z≦0.10, 0<y≦0.04), and the additive components are B ₂ O ₃ , SiO ₂ and MO (however,
MO consists of at least one metal oxide of BaO, SrO, CaO, MgO, and ZnO, and
The composition range of B ₂ O ₃ , the SiO ₂ and the MO is shown in the triangular diagram showing these compositions in mol%.
B ₂ O ₃ is 1 mol %, the SiO ₂ is 80 mol %, the above
Point (A) where MO is 19 mol%, and the above B ₂ O ₃ is 1 mol%,
Point (B) where the SiO ₂ is 39 mol% and the MO is 60 mol%
and the B ₂ O ₃ is 30 mol %, the SiO ₂ is 0 mol %,
Point (C) where the MO is 70 mol%, the B ₂ O ₃ is 90 mol%, the SiO ₂ is 0 mol%, and the MO is 10 mol%.
point (D), the B ₂ O ₃ is 90 mol %, the SiO ₂ is 10 mol %
mol%, the point (E) where the MO is 0 mol%, and the point (E) where the MO is 0 mol%;
B ₂ O ₃ is 20 mol %, SiO ₂ is 80 mol %,
a step of preparing a mixture characterized in that the mixture is within a region surrounded by six straight lines sequentially connecting points (F) where MO is 0 mol %; A method for manufacturing a porcelain capacitor, comprising: making a molded product; firing the molded product having the electrode portion in a non-oxidizing atmosphere; and heat-treating the molded product obtained by the firing in an oxidizing atmosphere. .