JPH0532896B2 - - 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 in which a dielectric ceramic layer is sandwiched between at least two internal electrodes, and a method for manufacturing the same. [Conventional technology] Conventionally, when manufacturing multilayer ceramic capacitors,
A conductive paste of noble metal such as platinum or palladium is printed in a desired pattern on an unsintered porcelain sheet (green sheet) made of dielectric porcelain raw material powder,
A plurality of these sheets were stacked and pressed together, and fired at 1300°C to 1600°C in an oxidizing atmosphere. Through this firing, the unsintered porcelain sheet made of the dielectric porcelain raw material powder becomes a dielectric porcelain layer, and the conductive paste of noble metal such as platinum or palladium becomes an internal electrode. As mentioned above, if a conductive paste containing a noble metal such as platinum or palladium is used as a main component, the temperature will exceed 1300℃ to 1600℃ in an oxidizing atmosphere.
The desired internal electrodes can be obtained even by firing at such high temperatures. 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, filed by the applicant, describes (Ba _kx M _x )O _k TiO ₂ (where M is Mg and/or
Disclosed is a dielectric ceramic composition comprising a basic component consisting of Zn or Zn) and additive components consisting of Li ₂ O and SiO ₂ . In addition, Japanese Patent Publication No. 61-14608 describes the dielectric ceramic composition described in the above-mentioned Japanese Patent Publication No. 61-14607.
Instead of Li ₂ O and SiO ₂ , Li ₂ O, SiO ₂ and MO (where MO is one selected from BaO, CaO and SrO)
A dielectric ceramic composition is disclosed that includes an additive component consisting of a metal oxide or two or more metal oxides. In addition, in Special Publication No. 61-14609, (Ba _kxy
M _x L _y ) O _k TiO ₂ (where M is Mg and/or Zn,
L is a basic component consisting of Sr and/or Ca),
A dielectric ceramic composition is disclosed that includes an additive component consisting of Li ₂ O and SiO ₂ . Furthermore, in Japanese Patent Publication No. 61-14610, _{Li 2} O, SiO _{2 and}
A dielectric ceramic composition containing an additive component consisting of MO (where MO is one or more metal oxides selected from BaO, CaO, and SrO) is disclosed. In addition, in Special Publication No. 61-14611, (Ba _kx
A basic component consisting of M _x )O _k TiO ₂ (where M is one or more metal elements selected from Mg, Zn, Sr, and Ca) and an additive component consisting of B ₂ O ₃ and SiO ₂ A dielectric ceramic composition comprising: In addition, in Special Publication No. 1595/1983, (Ba _kx M _x )
A basic component consisting of O _k TiO ₂ (where M is one or more metal elements selected from Mg, Zn, Sr and Ca), B ₂ O ₃ and MO (where MO is BaO,
A dielectric ceramic composition containing an additive component consisting of one or more metal oxides selected from MgO, ZnO, SrO, and CaO is disclosed. In addition, Japanese Patent Publication No. 62-1596 describes the dielectric ceramic composition described in Japanese Patent Publication No. 62-1595 mentioned above.
Instead of B ₂ O ₃ and MO, it consists of B ₂ O ₃ , SiO ₂ and MO (where MO is one or more metal oxides selected from BaO, MgO, ZnO, SrO and CaO) A dielectric ceramic composition is disclosed that includes an additive component. If the dielectric ceramic composition disclosed in these documents is used as a dielectric layer, a ceramic capacitor can be obtained by firing at a temperature of 1200°C or less in a reducing atmosphere, and the dielectric ceramic composition can be used as a dielectric layer. The dielectric constant can be set to 2000 or more, and the temperature change rate of the dielectric constant can be made within the range of -10% to +10% at -25°C to +85°C. [Problems to be Solved by the Invention] Incidentally, as the density of electronic circuits has increased in recent years, there has been a strong demand for miniaturization of ceramic capacitors. Furthermore, it has been desired to develop a ceramic capacitor equipped with a dielectric ceramic composition having a large dielectric constant. In addition, since ceramic capacitors are used in various environments, dielectric ceramic compositions with a smaller rate of change in dielectric constant over a wider temperature range than the dielectric ceramic compositions disclosed in the above-mentioned publications are needed. There was a desire to develop a ceramic capacitor with Therefore, the purpose of the present invention is to reduce the relative permittivity of 3000 or more and the dielectric loss even though it can be obtained by firing at 1200°C or lower in a non-oxidizing atmosphere.
tan δ is 2.5% or less, resistivity ρ is 1×10 ⁶ MΩ・cm or more, and the temperature change rate of relative permittivity is -55℃~
-15% to +15% at 125℃ (based on 25℃), -25℃ to
The object of the present invention is to provide a ceramic capacitor equipped with a dielectric ceramic composition whose temperature ranges from -10% to +10% (based on 20°C) at 85°C, and a method for manufacturing the same. [Means for Solving the Problems] A ceramic capacitor according to the present invention includes a dielectric ceramic layer made of a dielectric ceramic composition, and at least two or more internal electrodes sandwiching the dielectric ceramic layer, The dielectric ceramic composition consists of 100 parts by weight of a basic component and 0.2 to 5 parts by weight of an additive component, and the basic component is ( _Bakx M _x )O _k (Ti _1-z R _z )O _{2- z/2} (However, M is Mg and/or Zn, R is Sc, Y,
One or more metal elements selected from Gd, Dy, Ho, Er, and Yb, k, x, and z are values satisfying 1.00≦k≦1.05 0.01≦x≦0.10 0.002≦z≦0.06) The additive components are B ₂ O ₃ , SiO ₂ and MO (however, MO
is composed of one or more metal oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the B ₂ O ₃ , the SiO ₂ and the MO is within the range of these compositions. In the triangular diagram showing in mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
a first point A having a composition of 19 mol % of the MO; 1 mol % of the B ₂ O ₃ ; and 39 mol % of the SiO ₂ ;
a second point B having a composition of 60 mol % of the MO; 29 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a third point C having a composition of 70 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a fourth point D having a composition of 9 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 9 mol % of the SiO ₂ ;
A fifth point E having a composition of 1 mol% of the MO; 19 mol% of the B ₂ O ₃ ; 80 mol% of the SiO ₂ ;
This is within a region surrounded by six straight lines connecting in this order the sixth point F where the MO has a composition of 1 mol %. Here, the value of k is preferably in the range of 1.00≦k≦1.05. When the value of k is less than 1.00, the resistivity ρ is 1×
10 ⁶ MΩ・cm, the temperature change rate of capacitance ΔC _-55 and ΔC ₁₂₅ deviate from -15% to +15%,
ΔC _-25 and ΔC ₈₅ deviate from -10% to +10%, and k
If the value of k exceeds 1.05, it becomes impossible to obtain a dense sintered body, but if the value of k is in the range of 1.00≦k≦1.05, a dense sintered body with the desired electrical properties can be obtained. be. Further, the value of x is preferably in the range of 0.01≦x≦0.10. If the value of x is less than 0.01, the capacitance temperature change rate ΔC _-55 will deviate from -15% to +15%, and the value of x will be 0.10.
When the temperature change rate of capacitance ΔC ₈₅ exceeds −10
It deviates from %~+10%, but the value of x is 0.01≦
This is because in the range of x≦0.10, a material having desired electrical characteristics can be obtained. Note that Mg and Zn, which are M components, work in almost the same way, and desired electrical characteristics can be obtained by using one or both of Mg and Zn within a range that satisfies 0.01≦x≦0.10. I can do it. Further, the value of z is preferably in the range of 0.002≦z≦0.06. When the value of z is less than 0.002, the temperature change rate of capacitance ΔC _-55 deviates from -15% to +15%,
If ΔC _-25 deviates from -10% to +10% and the value of z exceeds 0.06, a dense sintered body cannot be obtained, but in the range of 0.002≦z≦0.06, the desired electrical This is because a dense sintered body having characteristics can be obtained. Furthermore, the R component contributes to improving the temperature characteristics of capacitance. That is, by adding the R component, the temperature change rate of capacitance ΔC -55 to ΔC ₁₂₅ in the range of _-55 °C to 125°C can be easily kept within the range of -15% to +15%. with −25℃~85
Temperature change rate of capacitance in the range ΔC _-25 to ΔC ₈₅
can be easily kept within the range of -10% to +10%, and the fluctuation range of the temperature change rate of capacitance in each temperature range can be reduced. Moreover, the R component has the effect of increasing the resistivity ρ and the effect of increasing the sinterability. Note that the R components Sc, Y, Gd, Dy, Ho, Er, and Yb work in almost the same way, and the same effect can be obtained even if one selected from these is used or a combination of several is used. is obtained. However, the value of z is desirably within the range of 0.002≦z≦0.06, regardless of whether there is one type of R component or multiple types of R components. In the composition formula showing the basic components, x, z, and k of course indicate the number of atoms of each element. In addition, a trace amount of MnO ₂ (preferably 0.05 to 0.05
A mineralizing agent such as 0.1% by weight) may be added to improve sinterability. Further, other substances may be added as necessary. Further, the starting materials for obtaining the basic components may be oxides or hydroxides other than those shown in the examples, such as BaO, SrO, CaO, or other compounds. Next, the amount of the additive component added is preferably in the range of 0.2 to 5 parts by weight per 100 parts by weight of the basic component. If the amount of added ingredients is less than 0.2 parts by weight,
Even if the firing temperature is 1250°C, a dense sintered body cannot be obtained, and if the amount of additive components exceeds 5 parts by weight, the dielectric constant ε _s becomes less than 3000, and the capacitance temperature This is because desired electrical characteristics can be obtained when the rate of change ΔC _-55 deviates from -15% to +15%, but the added component is in the range of 0.2 to 5 parts by weight. The composition of the additive component is preferably within the area surrounded by six straight lines connecting the first to fifth points A to F of the triangular diagram showing the composition ratio of B ₂ O ₃ -SiO ₂ -MO in mol%. . If the composition of the additive component is outside this range, a dense sintered body cannot be obtained, but if the composition is within this range, a sintered body with desired electrical characteristics can be obtained. . Note that the starting materials for the additive components may be other compounds such as oxides and hydroxides. Next, the method for manufacturing a porcelain capacitor according to the present invention includes the steps of preparing a mixture of unsintered porcelain powder consisting of the above basic components and additive components, and forming an unsintered porcelain sheet consisting of the mixture. process and
a step of forming a laminate in which the unsintered porcelain sheet is sandwiched between at least two or more conductive paste films; a step of firing the laminate in a non-oxidizing atmosphere; and a step of firing the laminate after the firing. The method includes a step of heat treatment in an oxidizing atmosphere. Here, the firing temperature in the non-oxidizing atmosphere can be varied depending on the electrode material. When using nickel as the internal electrode, the temperature is 1050℃~
Almost no aggregation of nickel particles occurs in the 1200°C range. Furthermore, 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. Furthermore, the temperature of the heat treatment in the oxidizing atmosphere can be varied in consideration of the oxidation of the electrode material such as nickel and the porcelain. The temperature of this heat treatment was 600°C in the example, but
The temperature is not limited to this, but may be lower than the sintering temperature, preferably 500℃ to 1000℃.
A range of ℃ is preferable. Note that the present invention is of course applicable to general single-layer ceramic capacitors other than multilayer ceramic capacitors. [Example] First, the preparation method of sample No. 1 in Table 1 and its electrical characteristics will be explained. Preparation of Basic Components The compounds of Formulation 1 were each weighed and wet mixed for 15 hours to obtain a raw material mixture.

[Table] Here, the weight (g) and molar parts of the compound of Formulation 1 are calculated from the general formula of the basic components (Ba _kx M _x )O _k (Ti _1-z R _z )O _2-z/2 …(1 _{) is ( Ba0.98Mg0.03Zn0.01 ) O1.02 ( Ti0.98Er0.02 ) O1.99 . _ _ _} Next, after drying this raw material mixture at 150°C for 4 hours,
It was crushed and calcined in the air at a temperature of about 1200°C for 2 hours to obtain a powder of the basic component. Preparation of additive components In addition, each compound of formulation 2 was weighed and mixed,
300 c.c. of alcohol was added to this mixture, which was stirred for 10 hours using an alumina ball in a polyethylene pot, and then pre-calcined in the air at a temperature of 1000°C for 2 hours.

[Table] Here, the weight (g) and molar parts of the compound of formulation 2 are: B ₂ O ₃ is 1 mol %, SiO ₂ is 80 mol %, MO is
19 mol% {BaO (3.8 mol%) + CaO (3.8 mol%) +
This value was calculated so that the composition would be SrO (3.8 mol%) + MgO (3.8 mol%) + ZnO (3.8 mol%). Next, the material obtained by this calcination is 300c.c.
The mixture was placed in an alumina pot with water and ground with an alumina ball for 15 hours, and then dried at 150°C for 4 hours to obtain a powder of the additive component. In addition, the contents of MO are BaO, CaO, SrO, MgO
As shown in Table 1, the proportions of ZnO and ZnO are both 20 mol%. Preparation of slurry Next, 2 parts by weight (20 g) of the above additive components were added to 100 parts by weight (1000 g) of the basic component, and an aqueous solution of acrylic ester polymer, glycerin, and condensed phosphate was further added. Add an organic binder at 15% by weight based on the total weight of the basic component and additive components, and further add 50% by weight of water,
These were placed in a ball mill, pulverized and mixed to prepare a slurry of porcelain raw materials. Formation of an unsintered porcelain sheet Next, the above slurry is degassed by putting it into a vacuum defoaming machine, and this slurry is put into a reverse roll coater, and the thin film molded product obtained from this is continuously coated on a long polyester film. At the same time, it is heated to 100℃ and dried on the same film.
A green porcelain sheet with a thickness of about 25 μm was obtained. This sheet is long, but it is cut into 10cm squares. Preparation and Printing of Conductive Paste On the other hand, conductive paste for internal electrodes was prepared by placing 10 g of nickel powder with an average particle size of 1.5 μm and 0.9 g of ethyl cellulose dissolved in 9.1 g of butyl carbitol in a stirrer. Obtained by stirring for hours. Then, add this conductive paste to a length of 14
After printing on one side of the unsintered porcelain sheet through a screen having 50 patterns of 7 mm in width and 7 mm in width, it was dried. Lamination of unsintered porcelain sheets Next, two unsintered porcelain sheets were laminated with the above-mentioned printed side facing up. At this time, the adjacent upper and lower sheets were arranged so that their printed surfaces were shifted by about half in the longitudinal direction of the pattern. Furthermore, four unsintered porcelain sheets each having a thickness of 60 μm were laminated on the upper and lower surfaces of this laminate. Pressing and cutting of the laminate Next, this laminate was pressed at a temperature of about 50° C. by applying a load of about 40 tons in the thickness direction. Thereafter, this laminate was cut into grid shapes to obtain 50 laminate chips. Firing of the Laminated Chip Next, the laminated chip 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 the air atmosphere to burn the organic binder. Thereafter, the atmosphere in the furnace was changed from air to a reducing atmosphere of H ₂ (2% by volume) + N ₂ (98% by volume).
Then, while maintaining this reducing atmosphere in the furnace, the heating temperature of the stacked chips was increased from 600°C to the sintering temperature of 1150°C at a rate of 100°C/h.
After holding 1150℃ (maximum temperature) for 3 hours, 100℃
The temperature was lowered to 600℃ at a rate of ℃/h, the atmosphere was changed to atmospheric atmosphere (oxidizing atmosphere), and the temperature was lowered to 600℃.
It was held for 30 minutes to perform oxidation treatment, and then cooled to room temperature to obtain a laminated sintered chip. Formation of external electrodes Next, a conductive paste consisting of zinc, glass frit, and vehicle is applied to the side surface of the laminated sintered chip where the electrodes are exposed, dried, and then exposed to air for 550 min. A zinc electrode layer is formed by baking for 15 minutes at a temperature of An electrode was formed. As a result, as shown in FIG. 1, a multilayer ceramic capacitor 10 is obtained in which a pair of external electrodes 16 are formed on a multilayer sintered chip 15 consisting of three dielectric ceramic layers 12 and two internal electrodes 14. It was done. Here, the external electrode 16 includes a zinc electrode layer 18 and
A copper layer 20 formed on this zinc electrode layer 18
and a Pb-Sn solder layer 22 formed on this copper layer 20. The thickness of the dielectric ceramic layer 12 of this multilayer ceramic capacitor 10 is 0.02 mm, and the opposing area of the pair of internal electrodes 14 is 5 mm x 5 mm = 25 mm ² . Further, the composition of the dielectric ceramic layer 12 after sintering is substantially the same as the mixed composition of the basic components and additive components before sintering. Measurement of Electrical Characteristics Next, the electrical _{characteristics} of the multilayer ceramic capacitor 10 were measured and the average values were calculated. Rate ρ is 4.7×10 ⁶ MΩ・cm, capacitance change rate ΔC _-55 at -55℃ and +125℃ based on capacitance at 25℃, ΔC ₁₂₅ is -11.5%, +6.5%, The capacitance change rates ΔC -25 and ΔC ₈₅ at -25°C and + ₈₅ °C based on the capacitance at 20°C were -6.5% and -5.2%. Note that the electrical characteristics were measured in the following manner. (A) The relative dielectric constant ε _s is calculated by measuring the capacitance under the conditions of temperature 20°C, frequency 1kHz, and voltage (effective value) 1.0V, and this measured value and the opposing area of the pair of internal electrodes 14 25
mm ² and the dielectric ceramic layer 1 between the pair of internal electrodes 14
It was calculated from the thickness of 2, 0.02 mm. (B) Dielectric loss tan δ (%) was measured under the same conditions as the above measurement of 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℃, +25℃, +
At each temperature of 40℃, +60℃, +85℃, +105℃, +125℃, frequency 1kHz, voltage (effective value) 1.0V
The capacitance was measured under the following conditions, and the rate of change at each temperature with respect to the capacitance at 20°C and 25°C was obtained. The preparation method of sample No. 1 and its characteristics have been described above, but for samples No. 2 to 81, the composition of the basic components and additive components, their ratios, and the firing temperature in a reducing atmosphere were also determined. Except for the changes shown in Tables 1 and 2, a multilayer ceramic capacitor was prepared in exactly the same manner as for sample No. 1, and its electrical characteristics were measured in the same manner. Table 1 shows the composition of the basic components and additive components of each sample, and Table 2 shows the firing temperature and electrical characteristics of each sample. In addition, x, z, k in the basic component column of Table 1 are as follows:
The number of atoms of each element in the composition formula (1) of the basic components mentioned above,
That is, it shows the ratio of the number of atoms of each element when the number of atoms of (Ti+R) is 1. In addition, Mg and Zn in the x column indicate the contents of M in the basic component composition formula (1) mentioned above, and Sc, Y, and
Gd, Dy, Ho, Er, and Yb indicate the content of R in the basic component composition formula (1) described above. These columns show the number of these atoms, and the total column shows the total value of Mg and Zn. The amount of the additive component added is shown in parts by weight based on 100 parts by weight of the basic component. In the MO content column of the additive components, the proportions of BaO, MgO, ZnO, SrO, and CaO are shown in mol%. In Table 2, the temperature characteristics of capacitance are 25℃
The capacitance change rate at -55℃ and +125℃ based on the capacitance of is ΔC _-55 (%) and ΔC ₁₂₅ (%),
The capacitance change rate at -25°C and +85°C based on the capacitance at 20°C is shown as ΔC _-25 (%) and ΔC ₈₅ (%).

【table】

【table】

【table】

[Table] Samples marked with * are comparative examples

【table】

【table】

[Table] Samples marked with * are comparative examples.As is clear from Tables 1 and 2, in the samples according to the present invention, in a non-oxidizing atmosphere,
When fired at 1200℃ or less, the dielectric constant ε _s is 3000 or more,
tan δ is 2.5% or less, resistivity ρ is 1 × 10 ⁶ MΩ・cm or more, temperature change rate of capacitance ΔC _-55 and ΔC ₁₂₅ are -
15% to +15%, ΔC _-25 and ΔC ₈₅ -10% to +10%
, which makes it possible to obtain a ceramic capacitor with desired characteristics. On the other hand, sample No. 11-13, 26, 31, 32, 40-45,
49, 50, 55, 56, 62, 63, 69, 80, and 81 cannot achieve the object of the present invention. Therefore, these are outside the scope of the present invention. Table 2 shows the temperature change rate of capacitance ΔC _-55 ,
Although only ΔC ₁₂₅ , ΔC _-25 , and ΔC ₈₅ are shown, the temperature change rate ΔC of various capacitances in the range of -25°C to +85°C for samples belonging to the scope of the present invention is -10% to +85°C. +
10%, and the rate of change of various capacitances ΔC in the range -55°C to +125°C is -15% to +15°C.
It is within the range of %. Next, the reasons for limiting the composition range of the dielectric ceramic composition of the present invention will be described. First, as shown in sample No. 32, when the value of x is zero, the temperature change rate ΔC _-55 of capacitance is -15%.
Although it is outside the range of ~+15%, as shown in Sample Nos. 33 and 34, when the value of x is 0.01, desired electrical characteristics can be obtained. Therefore, the lower limit of x is 0.01. On the other hand, as shown in samples No. 40 to 44, the value of x is
0.12, the temperature change rate of capacitance ΔC ₈₅ is −
Although it is outside the range of 10% to +10%, desired electrical characteristics can be obtained when the value of x is 0.10, as shown in sample Nos. 38 and 39. Therefore, the upper limit of x is 0.10. Note that Mg and Zn, which are M components, work in almost the same way, and desired electrical characteristics can be obtained by using one or both of Mg and Zn within a range that satisfies 0.01≦x≦0.10. I can do it. When the value of k is 0.98, as shown in sample No. 45, ρ becomes significantly lower than 1×10 ⁶ MΩ・cm, and the temperature change rate of capacitance ΔC _-55 , ΔC _-25 , ΔC ₈₅
However, as shown in sample No. 46, when the value of k is 1.00, desired electrical characteristics can be obtained. Therefore, the lower limit of the value of k is 1.00. On the other hand, the value of k is 1.07 as shown in sample No. 49.
Although a dense sintered body cannot be obtained in the case of sample No.
48, when the value of k is 1.05, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of k is
It is 1.05. The value of z is 0 as shown in sample Nos. 50, 56, and 63.
In the case of , the temperature change rate of capacitance ΔC _-55 , ΔC _-25
are not within -15% and -10%, respectively, but the value of z is
In the case of 0.002, desired electrical characteristics are obtained.
Therefore, the lower limit of z is 0.002. On the other hand, as shown in sample Nos. 55, 62, 69, 80, and 81, when the value of z is 0.07, a dense sintered body cannot be obtained even if fired at 1250°C; ,61,68,
As shown in 78 and 79, when it is 0.06, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of z is 0.06. In addition, R components Sc, Y, Gd, Dy, Ho, Er and
Yb works in almost the same way, and one selected from these
Similar results can be obtained using one or a combination of two or more. It is desirable that the value of z be in the range of 0.002 to 0.06, regardless of whether there is one type of R component or multiple types of R components. Note that the component represented by R in the compositional formula contributes to improving the temperature characteristics of capacitance. In other words, by adding the R component, the temperature change rate of capacitance ΔC -55 to ΔC ₁₂₅ in the range of _-55 °C to 125°C is reduced to -15
It is possible to easily keep the temperature change rate of capacitance ΔC _-25 to ΔC ₈₅ in the range of -10% to +10% in the range of -25℃ to 85℃. In addition, the range of fluctuation in the temperature change rate of capacitance in each temperature range can be reduced. Moreover, the R component has the effect of increasing the resistivity ρ and the effect of increasing the sinterability. In addition, if the amount of added components is zero, the sample
As is clear from No. 26, a dense sintered body cannot be obtained even if the firing temperature is 1250°C, but as shown in Sample No. 27, the addition amount is 100 parts by weight of the basic components. In the case of 0.2 parts by weight, desired electrical properties can be obtained by firing at 1190°C. Therefore, the lower limit of the added components is 0.2 parts by weight. On the other hand, as shown in sample No. 31, when the amount of the additive component is 7.0 parts by weight, the relative permittivity ε _s is less than 3000, and the temperature change rate ΔC _-55 of capacitance is -15 % to +15%, but as shown in sample No. 30, when the amount added is 5.0 parts by weight, desired electrical characteristics can be obtained. Therefore, the upper limit of the amount added is 5.0 parts by weight. 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 that B ₂ O ₃ of sample No. 1 is 1.
mol%, _{SiO 2} is ₈₀ mol _% , MO is 19 mol%. The third point C shows the composition of sample No. 3 with 29 mol% of B ₂ O ₃ , 1 mol% of SiO ₂ and 70 mol% of MO. D is sample No. 4 with 90 mol% B ₂ O ₃ ;
It shows a composition of 1 mol% of SiO ₂ and 9 mol% of MO,
At the fifth point E, B ₂ O ₃ of sample No. 5 is 90 mol%,
Showing a composition of 9 mol% SiO ₂ and 1 mol% MO,
At the sixth point F, B ₂ O ₃ of sample No. 6 is 19 mol%,
The composition is 80 mol% SiO ₂ and 1 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 the first to sixth points A to F of the triangular diagram in this 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 Nos. 11 to 13, a dense sintered body cannot be obtained. In addition, the MO component may be any one of BaO, MgO, ZnO, SrO, or CaO, as shown in Sample Nos. 14 to 18, or in an appropriate ratio as shown in other samples. Good too. [Effects of the Invention] According to the present invention, since the composition of the dielectric ceramic composition is as described above, the dielectric constant is 3000 or more, the dielectric loss tan δ is 2.5% or less, and the resistivity ρ is 1×10 ⁶ M
Ω・cm or more, and the temperature change rate of relative dielectric constant is -15% to +15% (based on 25°C) from -55°C to 125°C, -10% to +10% from -25°C to 85°C It is possible to provide a ceramic capacitor with a dielectric ceramic composition that falls within the range of (with reference to 20°C). Further, according to the present invention, since it can be obtained by firing at a temperature of 1200°C or less in a non-oxidizing atmosphere, a conductive paste of a base metal such as nickel is applied to a green sheet, and the green sheet and the conductive paste are A porcelain capacitor can be manufactured by a method in which both are fired at the same time.

[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)

[Claims] 1. A dielectric ceramic layer made of a dielectric ceramic composition;
In this ceramic capacitor having at least two or more internal electrodes sandwiching a dielectric ceramic layer, the dielectric ceramic composition comprises 100 parts by weight of a basic component and 0.2 to 5 parts by weight of an additive component. It consists of a fired mixture, and the basic components are ( _Bakx M _x )O _k (Ti _1-z R _z )O _2-z/2 (where M is Mg and/or Zn, R is Sc, Y ，
One or more metal elements selected from Gd, Dy, Ho, Er, and Yb, k, x, and z are values satisfying 1.00≦k≦1.05 0.01≦x≦0.10 0.002≦z≦0.06) The additive components are B ₂ O ₃ , SiO ₂ and MO (however, MO
is composed of one or more metal oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the B ₂ O ₃ , the SiO ₂ and the MO is within the range of these compositions. In the triangular diagram showing in mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
a first point A having a composition of 19 mol % of the MO; 1 mol % of the B ₂ O ₃ ; and 39 mol % of the SiO ₂ ;
a second point B having a composition of 60 mol % of the MO; 29 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a third point C having a composition of 70 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a fourth point D having a composition of 9 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 9 mol % of the SiO ₂ ;
a fifth point E in which the MO has a composition of 1 mol %; the B ₂ O ₃ is 19 mol %; the SiO ₂ is 80 mol %;
A ceramic capacitor characterized in that the MO is located within a region surrounded by six straight lines connecting in this order a sixth point F having a composition of 1 mol %. 2. A step of preparing a mixture made of unsintered porcelain powder, a step of forming an unsintered porcelain sheet made of the mixture, and a step of sandwiching the unsintered porcelain sheet between at least two or more conductive paste films. forming a laminate, firing the laminate in a non-oxidizing atmosphere, and heat-treating the fired laminate in an oxidizing atmosphere, the unsintered porcelain powder A mixture consisting of 100
It consists of a basic component of 0.2 to 5 parts by weight of an additive component, and the basic component is (Ba _kx M _x )O _k (Ti _1-z R _z )O _2-z/2 (However, M is Mg and/or Zn, R is Sc, Y,
One or more metal elements selected from Gd, Dy, Ho, Er, and Yb, k, x, and z are values satisfying 1.00≦k≦1.05 0.01≦x≦0.10 0.002≦z≦0.06) The additive components are B ₂ O ₃ , SiO ₂ and MO (however, MO
is composed of one or more metal oxides selected from BaO, SrO, CaO, MgO and ZnO), and the composition range of the B ₂ O ₃ , the SiO ₂ and the MO is within the range of these compositions. In the triangular diagram showing in mol%, the B ₂ O ₃ is 1 mol%, the SiO ₂ is 80 mol%,
a first point A having a composition of 19 mol % of the MO; 1 mol % of the B ₂ O ₃ ; and 39 mol % of the SiO ₂ ;
a second point B having a composition of 60 mol % of the MO; 29 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a third point C having a composition of 70 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 1 mol % of the SiO ₂ ;
a fourth point D having a composition of 9 mol % of the MO; 90 mol % of the B ₂ O ₃ ; 9 mol % of the SiO ₂ ;
a fifth point E in which the MO has a composition of 1 mol %; the B ₂ O ₃ is 19 mol %; the SiO ₂ is 80 mol %;
A method for manufacturing a ceramic capacitor, characterized in that the MO is located within a region surrounded by six straight lines connecting in this order a sixth point F having a composition of 1 mol %.