JP6413861B2 - Dielectric porcelain composition and electronic component - Google Patents

Description

  The present invention relates to a dielectric ceramic composition and an electronic component.

  In recent years, along with rapid progress in performance of electrical equipment, miniaturization and complexity of electrical circuits are also progressing rapidly. For this reason, electronic components are required to be further reduced in size and performance. That is, a dielectric ceramic composition and an electron having a high relative dielectric constant in order to maintain capacitance even when miniaturized while maintaining good temperature characteristics, and also having a high AC breakdown voltage for use under a high voltage Parts are required.

Conventionally, as a high dielectric constant dielectric ceramic composition widely used as a ceramic capacitor, a multilayer capacitor, a high frequency capacitor, a high voltage capacitor, etc., BaTiO ₃ —BaZrO ₃ —CaTiO ₃ — A material mainly composed of a SrTiO ₃ -based dielectric ceramic composition is known.

Since the conventional BaTiO ₃ —BaZrO ₃ —CaTiO ₃ —SrTiO ₃ based dielectric ceramic composition is ferroelectric, it must ensure high AC breakdown voltage while maintaining high capacitance and low dielectric loss. It was difficult. In addition, various rare earth elements are added to the conventional BaTiO ₃ —BaZrO ₃ —CaTiO ₃ —SrTiO ₃ based dielectric ceramic composition in order to obtain desired characteristics. Reduction is conventionally required.

JP-A-1994-302219 JP 2003-104774 A JP 2004-238251 A

  The present invention has been made in view of such circumstances, and an object thereof is to provide a dielectric ceramic composition having a high relative dielectric constant and AC breakdown voltage, a low dielectric loss, and good temperature characteristics and sinterability. . Another object of the present invention is to provide an electronic component having a dielectric layer composed of such a dielectric ceramic composition.

  As a result of intensive studies to achieve the above object, the present inventors have not used only one type of dielectric ceramic composition as the main component, but two types of dielectric ceramic composition as the main component. It was found that the above-mentioned object can be achieved by mixing at a predetermined ratio and further containing at least zinc oxide and bismuth oxide as subcomponents, thereby completing the present invention.

That is, the dielectric ceramic composition according to the present invention for solving the above problems is
And _{(Ba 1-x-y,} Ca x, Sr y) m (Ti 1-z-a, Zr z, Sn a) a first main composition represented by the composition formula of _{O 3,}
A second main composition represented by a composition formula of (Ba _1-α , Sr _α ) _n TiO ₃ ;
A dielectric ceramic composition comprising a first subcomponent comprising bismuth oxide,
0.01 ≦ x ≦ 0.30
0 <y ≦ 0.1
0.04 ≦ z ≦ 0.2
0 ≦ a ≦ 0.2
0.04 ≦ z + a ≦ 0.3
0 ≦ α ≦ 0.1
And
The sum of the content of the first main composition and the content of the second main composition is 100 parts by weight, the content of the second main composition is A parts by weight, and the content of the first subcomponent Is ₁ part by weight of B,
5 ≦ A ≦ 40
0.97 ≦ {(100−A) × m + A × n} × 0.01 ≦ 1.03
0.3 ≦ B ₁ ≦ 3
It is.

_Hereinafter, the dielectric represented by the composition formula of _{(Ba 1-x-y,} Ca x, Sr y) m (Ti 1-z-a, Zr z, Sn a) O 3 (x ≠ 0, z ≠ 0) The body ceramic composition may be referred to as a BCTZ-based dielectric ceramic composition. A dielectric ceramic composition represented by a composition formula of (Ba _1−α , Sr _α ) _n TiO ₃ (α ≠ 1) may be referred to as a BT-based dielectric ceramic composition.

  In the present invention, the first main composition, which is a BCTZ-based dielectric ceramic composition, and the second main composition, which is a BT-based dielectric ceramic composition, are contained in a predetermined ratio, and are further made of bismuth oxide. 1 subcomponent is contained, It is characterized by the above-mentioned. According to the present invention, it is possible to provide a dielectric ceramic composition having a high relative dielectric constant and AC breakdown voltage, low dielectric loss, and good temperature characteristics and sinterability.

  The dielectric ceramic composition according to the present invention preferably further satisfies 5 ≦ A ≦ 30.

The dielectric ceramic composition according to the present invention preferably further satisfies 0.3 ≦ B ₁ ≦ 1.5.

The dielectric ceramic composition according to the present invention further contains a second subcomponent made of zinc oxide, and when the content of the second subcomponent is B ₂ parts by weight, 0.45 ≦ B ₂ ≦ 10. It is preferable that

The dielectric ceramic composition according to the present invention further includes a third subcomponent composed of at least one oxide selected from the group consisting of La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, and Y. When the content of the third subcomponent is B ₃ parts by weight in terms of oxide, it is preferable that 0 <B ₃ ≦ 0.3.

The dielectric ceramic composition according to the present invention further includes a fourth subcomponent made of at least one oxide selected from the group consisting of Al, Ga, Si, Mg, In, and Ni. When the content of B is ₄ parts by weight in terms of oxide, it is preferable that 0.02 ≦ B ₄ ≦ 1.5.

The dielectric ceramic composition according to the present invention further includes a fifth subcomponent consisting of at least one oxide from the group consisting of Mn and Cr, and the content of the fifth subcomponent in terms of oxide. In the case of ₅ parts by weight of B, it is preferable that 0.01 ≦ B ₅ ≦ 0.6.

  The electronic component according to the present invention has a dielectric composed of the dielectric ceramic composition.

  There is no limitation in particular in the kind of electronic component which concerns on this invention. For example, single plate ceramic capacitors, feedthrough capacitors, multilayer ceramic capacitors, piezoelectric elements, chip inductors, chip varistors, chip thermistors, chip resistors, other surface mount (SMD) chip type electronic components, ring varistors, ESD protection devices, etc. Can be mentioned.

It is the schematic of the ceramic capacitor which concerns on one Embodiment of this invention. 6 is a schematic view of an enlarged cross-sectional view of a main part of a dielectric of a sample 4. FIG.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

Ceramic capacitor 2
As shown in FIG. 1, the ceramic capacitor 2 according to the embodiment of the present invention has a configuration including a dielectric 4 and a pair of electrodes 6 and 8 formed on the opposing surface thereof. The shape of the ceramic capacitor may be appropriately determined according to the purpose and application, but is preferably a disk-type capacitor in which the dielectric 4 has a disk shape. Further, the size may be appropriately determined according to the purpose and application.

Electrodes 6 and 8
The electrodes 6 and 8 are made of a conductive material. The conductive material used for the terminal electrodes 6 and 8 is not particularly limited, and may be determined as appropriate according to the application. Examples of the conductive material include Ag, Cu, Ni, and the like.

Dielectric 4
The dielectric 4 of the ceramic capacitor 2 is composed of a dielectric ceramic composition according to an embodiment of the present invention. The thickness of the dielectric 4 is not particularly limited, and may be appropriately determined according to the application.

The dielectric ceramic composition according to an embodiment of the present invention _is represented by a composition formula of _{(Ba 1-x-y,} Ca x, Sr y) m (Ti 1-z-a, Zr z, Sn a) O 3 A first main composition, a second main composition represented by a composition formula of (Ba _1-α , Sr _α ) _n TiO _3, a first subcomponent, a second subcomponent, and a third subcomponent , A dielectric ceramic composition having a fourth subcomponent and a fifth subcomponent. In the present invention, the second to fifth subcomponents may not be contained.

  X in the composition formula represents the ratio of Ca atoms to the A site atoms of the first main composition, and the range is 0.01 ≦ x ≦ 0.30. The range of x is preferably 0.03 ≦ x ≦ 0.17, more preferably 0.08 ≦ x ≦ 0.16. When Ca is contained in the above range, the AC breakdown voltage and the capacity-temperature characteristic tend to be improved. If x is too small, the AC breakdown voltage and capacity-temperature characteristics tend to deteriorate, and if x is too large, the relative permittivity tends to decrease.

  Y in the composition formula represents the ratio of Sr to the A site atom of the first main composition, and the range is 0 <y ≦ 0.1. The range of y is preferably 0.006 ≦ y ≦ 0.04. When Sr is contained in the above range, the relative permittivity tends to be improved. Further, if y is too small, the relative permittivity tends to deteriorate, and if y is too large, the relative permittivity and the capacity-temperature characteristics on the high temperature side tend to deteriorate.

  Z in the composition formula represents the ratio of Zr to the B site atoms of the first main composition, and the range is 0.04 ≦ z ≦ 0.2. The range of z is preferably 0.06 ≦ z ≦ 0.15. When Zr is contained in the above range, the relative dielectric constant and the capacitance-temperature characteristic on the low temperature side tend to be good. If z is too small, the relative permittivity and the low temperature side capacity-temperature characteristic tend to deteriorate, and if z is too large, the relative dielectric constant and the high temperature side capacity-temperature characteristic tend to deteriorate.

  In the composition formula, a represents the ratio of Sn in the B site atoms of the first main composition, and the range is 0 ≦ a ≦ 0.2. The range of a is preferably 0 ≦ a ≦ 0.15. By containing Sn in the above range, there is an effect in improving the relative dielectric constant and improving the capacitance-temperature characteristics on the low temperature side. Sn may not be contained. That is, a = 0 may be used. If a is too large, the relative permittivity, the AC breakdown voltage, and the capacity-temperature characteristics on the high temperature side tend to deteriorate.

  Z + a in the composition formula represents the total ratio of Zr and Sn in the B site atom of the first main composition, and the range is 0.04 ≦ z + a ≦ 0.3. The range of z + a is preferably 0.06 ≦ z + a ≦ 0.2. When Zr and Sn are contained in the above ranges, the relative permittivity and the temperature characteristics on the high temperature side tend to be improved. If z + a is too small, the relative permittivity, dielectric loss, AC breakdown voltage, and low-temperature capacity-temperature characteristics tend to deteriorate. If z + a is too large, the relative permittivity and the capacity-temperature characteristics on the high temperature side tend to deteriorate.

  M in the composition formula represents a molar ratio of Ba, Ca, and Sr that are A site atoms of the first main composition and Ti, Zr, and Sn that are B site components of the first main composition.

  Α in the composition formula represents the ratio of Sr atoms to the A site atoms of the second main composition, and the range is 0 ≦ α ≦ 0.1. Note that Sr may not be contained. That is, α = 0 may be used. If α is too large, the relative dielectric constant and the capacity-temperature characteristic on the high temperature side tend to deteriorate.

 N in the composition formula represents a molar ratio between Ba and Sr which are A site atoms of the second main composition and Ti which is a B site component of the second main composition.

  The first main composition and the second main composition are combined as a main component. The content of the main component is 100 parts by weight, and the content ratio of the second main composition is A parts by weight. The dielectric ceramic composition according to the present embodiment satisfies 5 ≦ A ≦ 40. The range of A is preferably 5 ≦ A ≦ 30. When A is too small, the capacity-temperature characteristic tends to deteriorate. If A is too large, the dielectric constant tends to deteriorate.

  The dielectric ceramic composition according to the present embodiment includes m in the composition formula of the first main composition, n in the composition formula of the second main composition, and A is 0.97 ≦ {(100−A ) × m + A × n} × 0.01 ≦ 1.03. Preferably, 0.97 ≦ {(100−A) × m + A × n} × 0.01 ≦ 1.01 is satisfied. If {(100−A) × m + A × n} × 0.01 is too small, the relative permittivity and the AC breakdown voltage tend to decrease. If {(100−A) × m + A × n} × 0.01 is too large, the sinterability tends to deteriorate and the relative permittivity tends to decrease.

  The first subcomponent is bismuth oxide. The dielectric ceramic composition according to the present embodiment contains 0.3 to 3 parts by weight of the first subcomponent with respect to 100 parts by weight of the main component. By setting the content of the first subcomponent within the above range, the dielectric constant, AC breakdown voltage, and capacity-temperature characteristics are improved. When the content of the first subcomponent is too small, the capacity-temperature characteristic on the low temperature side is deteriorated. If the content of the first subcomponent is too large, the relative dielectric constant, the AC breakdown voltage, and the capacity-temperature characteristics on the high temperature side are deteriorated.

  The second subcomponent is zinc oxide. In the dielectric ceramic composition according to the present embodiment, the content of the second subcomponent is not particularly limited, and the second subcomponent may not be included. It is preferable to contain 0.45-10 weight part of said 2nd subcomponent with respect to 100 weight part of said main components. By setting the content of the second subcomponent within the above range, the AC breakdown voltage, the capacity-temperature characteristic, and the sinterability are improved.

  The third subcomponent is at least one oxide selected from the group consisting of La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, and Y. Preferably, it is at least one oxide selected from the group consisting of Y, Gd, La, Sm, and Nd. In the dielectric ceramic composition according to the present embodiment, the content of the third subcomponent is not particularly limited, and the third subcomponent may not be included. The third subcomponent is preferably contained in an amount of 0 to 0.3 parts by weight (excluding 0 parts by weight) with respect to 100 parts by weight of the main component. Especially preferably, it is 0.01-0.09 weight part. By setting the content of the third subcomponent within the above range, reduction resistance, relative dielectric constant, AC breakdown voltage, and capacity-temperature characteristics are improved.

  The fourth subcomponent is at least one oxide selected from the group consisting of Al, Ga, Si, Mg, In, and Ni. Preferably, it is at least one oxide selected from the group consisting of Al, Ga, Mg, and Si. In the dielectric ceramic composition according to the present embodiment, the content of the fourth subcomponent is not particularly limited, and may not include the fourth subcomponent. It is preferable to contain 0.04 to 1.5 parts by weight of the fourth subcomponent with respect to 100 parts by weight of the main component. Particularly preferred is 0.05 to 1.2 parts by weight. By setting the content of the fourth subcomponent within the above range, the relative permittivity and the AC breakdown voltage are improved.

  The fifth subcomponent is at least one oxide selected from the group consisting of Mn and Cr. In the dielectric ceramic composition according to this embodiment, the content of the fifth subcomponent is not particularly limited, and may not include the fifth subcomponent. The fifth subcomponent is preferably contained in an amount of 0.01 to 0.6 parts by weight with respect to 100 parts by weight of the main component. Particularly preferred is 0.02 to 0.2 parts by weight. By setting the content of the fifth subcomponent within the above range, the relative permittivity, the AC breakdown voltage, the capacity-temperature characteristic, and the reliability at high temperatures are improved.

Manufacturing method of ceramic capacitor 2
Next, a method for manufacturing the ceramic capacitor 2 will be described.
First, a dielectric ceramic composition powder that forms the dielectric 4 shown in FIG. 1 after firing is manufactured.

A raw material for the main component (first main composition and second main composition) and a raw material for the first subcomponent to the fifth subcomponent are prepared. Examples of the main component material include Ba, Ca, Sr, Ti, Zr, and Sn oxides and / or materials that become oxides upon firing, and composite oxides thereof. For example, barium carbonate (BaCO ₃ ), calcium carbonate (CaCO ₃ ), strontium carbonate (SrCO ₃ ), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), tin oxide (SnO ₂ ), and the like can be used. It is not limited to the above compounds. For example, it is also possible to use various compounds that become oxides and titanium compounds after firing, such as hydroxides of the above metal elements.

  Moreover, there is no restriction | limiting in particular in the manufacturing method of the raw material of a main component. For example, it may be produced by a solid phase method or a liquid phase method such as a hydrothermal synthesis method or an oxalate method. From the viewpoint of manufacturing cost, it is preferable to manufacture by a solid phase method.

  There is no restriction | limiting in particular in the raw material of a 1st subcomponent-a 5th subcomponent. Various compounds that become the above oxides upon firing, for example, carbonates, nitrates, hydroxides, organometallic compounds, and the like can be appropriately selected and used.

  As a method for producing a dielectric ceramic composition according to an embodiment of the present invention, first and second main composition calcined powders are first produced separately.

  The first main composition calcined powder and the second main composition calcined powder are both mixed and mixed with the raw materials of each main composition. There is no particular limitation on the mixing method. For example, they can be mixed by wet mixing. Moreover, there is no restriction | limiting in particular also in the instrument used for wet mixing. For example, a ball mill can be used. In the case of mixing by wet mixing, dehydration drying is performed after wet mixing, and temporary baking is performed after dehydration drying. Each main composition calcined powder can be obtained by chemically reacting each raw material by calcining. The calcining temperature is preferably 1100 to 1300 ° C. and the calcining atmosphere is preferably in the air.

  The obtained first main composition calcined powder and second main composition calcined powder are coarsely pulverized by, for example, a ball mill, an airflow pulverizer or the like, and then the first main composition calcined powder and the second main composition calcined powder. Powder and raw materials of the first to fifth subcomponents are mixed.

  The second subcomponent and the third subcomponent may be added in the form of a compound contained in the main composition calcined powder by mixing and calcining with the main composition raw material in advance. The sub-component and the third sub-component may be added as a calcined powder that has been reacted by mixing and calcining, and the second sub-component and / or the third sub-component are calcined separately, It may be added after.

 The main composition calcined powder and the raw materials of the first to fifth subcomponents are mixed and then pulverized. There is no particular limitation on the method of pulverization. For example, fine pulverization can be performed using a pot mill or the like. There is no particular limitation on the average particle size after pulverization. It is preferable to pulverize so that the average particle size is about 0.5 to 2 μm.

 After pulverization, dehydration and drying are performed, and after dehydration and drying, an organic binder is added. There is no restriction | limiting in particular in an organic binder, The organic binder normally used in this technical field can be used. An example of the organic binder is polyvinyl alcohol (PVA).

  After adding the organic binder, granulation and sizing are performed to obtain a granular powder. The obtained granular powder is molded to obtain a molded product.

  The obtained molded product is finally fired to obtain a sintered body (dielectric 4) of the dielectric ceramic composition. There is no particular limitation on the firing atmosphere, but firing in air is preferable. There are no particular limitations on the firing temperature and firing time. The firing temperature is preferably 1150 to 1300 ° C.

  The ceramic capacitor shown in FIG. 1 is formed by printing electrodes on a predetermined surface of the sintered body (dielectric 4) of the obtained dielectric ceramic composition and baking it as necessary to form the electrodes 6 and 8. Get 2.

  The ceramic capacitor 2 of the present invention manufactured as described above is mounted on a printed circuit board through lead terminals, for example, and used for various electronic devices.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, it can implement in a various aspect within the range which does not deviate from the summary of this invention. .

Further, the dielectric ceramic composition of the present invention can reduce the amount of rare earth elements used as compared with the conventional BaTiO ₃ —BaZrO ₃ —CaTiO ₃ —SrTiO ₃ based dielectric ceramic composition.

  In the above-described embodiment, the single-plate ceramic capacitor having a single dielectric layer is exemplified as the electronic component according to the present invention. However, the electronic component according to the present invention is not limited to the single-plate ceramic capacitor. For example, it may be a multilayer ceramic capacitor produced by a normal printing method or sheet method using a dielectric paste and an electrode paste containing the above dielectric ceramic composition, and the above dielectric ceramic composition is used. The feedthrough capacitor may be used, or other electronic components may be used.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

As the main composition material, barium carbonate (BaCO ₃ ), calcium carbonate (CaCO ₃ ), strontium carbonate (SrCO ₃ ), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ) and tin oxide (SnO ₂ ), respectively, Got ready. Furthermore, bismuth oxide (Bi ₂ O ₃ ) as the first subcomponent raw material, zinc oxide (ZnO) as the second subcomponent raw material, La, Pr, Pm, Nd, Sm, Eu, Oxidation of one or more elements selected from the group consisting of Gd and oxidation of one or more elements selected from the group consisting of Al, Ga, Si, Mg, In, Ni as the fourth subcomponent material The oxides of Mn and / or Cr were prepared as materials for the fifth subcomponent.

The main composition raw materials were weighed so that the compositions after firing the first main composition were the compositions shown in Tables 1 and 2. After weighing, each raw material was blended. The blending was performed by performing wet mixing and stirring for 3 hours in a ball mill. The mixture after the wet mixing and stirring was dehydrated and dried. After dehydration and drying, it was calcined at 1170-1210 ° C. to obtain a first main composition calcined powder.

The main composition raw materials were weighed so that the compositions after firing the second main composition were the compositions shown in Tables 1 and 2. After weighing, each raw material was blended. The blending was performed by performing wet mixing and stirring for 3 hours in a ball mill. The mixture after the wet mixing and stirring was dehydrated and dried. After dehydration and drying, calcined at 1170 to 1210 ° C. to obtain a calcined powder of the second main composition.

  The first main composition calcined powder and the second main composition calcined powder were coarsely pulverized. Thereafter, the coarsely pulverized first main composition calcined powder, the coarsely pulverized second main composition calcined powder, and the first to fifth subcomponent raw materials (coarsely pulverized as necessary), It measured so that the composition after baking might become a composition shown in Table 1, 2, and mixed. And it grind | pulverized by the pot mill to the average particle diameter of about 0.5 micrometer-2 micrometers. The finely pulverized raw material powder was dehydrated and dried. Polyvinyl alcohol (PVA) was added as an organic binder to the raw material powder after dehydration and drying, and granulation and sizing were performed to obtain a granular powder.

  The granule powder was molded at a pressure of 300 MPa to obtain a disk-shaped molded product having a diameter of 16.5 mm and a thickness of 1.15 mm.

  The disk-shaped molded product was subjected to main firing at 1150 ° C. to 1300 ° C. in the air to obtain a sintered body.

  The composition after firing was confirmed by fluorescent X-ray analysis. And it confirmed that the composition after baking substantially corresponded with the composition at the time of the mixing of the main component and subcomponent before baking.

  A silver (Ag) paste was baked on both surfaces of the sintered body to form electrodes, and a ceramic capacitor was obtained. The electrical characteristics of the porcelain capacitors of sample numbers 1 to 137 in Tables 1 and 2 thus obtained were measured.

  Hereinafter, a measurement method and an evaluation method of each electrical characteristic will be described.

(Sinterability (sintered body density))
The density of the sintered body was calculated from the size and weight of the sintered body. When the sintered body density was 5.5 g / cm ³ or more, the sinterability was considered good. In Tables 1 and 2, the case where the sintered body density was 5.5 g / cm ³ or more was evaluated as ◯, and the case where it was less than 5.5 g / cm ^{3 was} evaluated as x. The reason why the standard is 5.5 g / cm ³ is that the strength of the sintered body is significantly lowered when the density of the sintered body is less than 5.5 g / cm ³ . In addition, about the sample whose sintered compact density is less than 5.5 g / cm < ³ >, the following measurement was not implemented because it was unnecessary.

(Relative permittivity (ε))
The relative dielectric constant ε was calculated from the capacitance measured with the digital LCR meter under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms with respect to the capacitor sample at a reference temperature of 20 ° C. (No unit). It is preferable that the relative dielectric constant is high. In this example, 8000 or more was considered good.

(Dielectric loss (tan δ))
The dielectric loss (tan δ) was measured with respect to the capacitor sample at a reference temperature of 20 ° C. with a digital LCR meter under conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms. The dielectric loss is preferably as low as possible. In this example, 1.5% or less was considered good.

(AC breakdown voltage (AC-Eb))
For AC breakdown voltage (AC-Eb), an AC electric field is gradually applied to both ends of the capacitor sample at 100 V / s, and the voltage at the time when a leakage current of 100 mA flows is measured. The breakdown voltage was determined. It is preferable that the AC breakdown voltage is high. In this example, 4.0 kV / mm or more was considered good.

(Temperature characteristics (E characteristics))
The capacitance of the capacitor sample is measured at −25 ° C. to 85 ° C. with a digital LCR meter under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 1 Vrms. The rate of change in capacitance at −25 ° C. and the rate of change in capacitance at 85 ° C. were calculated. In this example, + 20% to -55% satisfying the E characteristic was set as a preferable range.

(reliability)
The capacitor sample was put in a state where an AC voltage of 50 Hz was applied at 3 kV per 1 mm of dielectric in an atmosphere of 170 ° C. After maintaining in this state for 24 hours, the above-mentioned relative dielectric constant, dielectric loss, AC breakdown voltage, and temperature characteristics were measured.

  The reliability was determined to be good when the characteristics after holding for 24 hours were comparable to the characteristics before holding for 24 hours. That is, the value before each test of each characteristic was used as a parameter, and the case where the difference between the value after the test of each characteristic and the value before the test was 20% or less was considered good. In Tables 1 and 2, ◯ is given when all the characteristics are within the above-mentioned favorable range, and Δ is given when there are characteristics outside the above-mentioned good range. Even if the reliability is Δ, the object of the present invention can be sufficiently achieved if other characteristics are good.

(EPMA)
The sample 4 was mirror-polished and observed with EPMA, and mapping analysis of Ba, Ca, Ti, Zr, Zn, Bi, etc. was performed. FIG. 2 is a schematic diagram of an enlarged cross-sectional view of a main part of the dielectric material of the sample 4 prepared based on the measurement result of EPMA. Of the portion where Ba and Ti are present, the portion where Ca and Zr are present is defined as the portion where the first main composition 12 is present. Of the portion where Ba and Ti are present, the portion where Ca and Zr are not present is defined as the portion where the second main composition 14 is present. A portion different from both the first main composition 12 and the second main composition 14 was a portion where the other composition 16 was present. Examples of the other composition 16 include segregated particles of subcomponents. In FIG. 2, the description of the grain boundary is omitted.

(Evaluation)
From Samples 1 to 8, when x (Ca content) in the composition formula of the first main composition is 0.01 ≦ x ≦ 0.30 (Samples 2 to 7), when x is 0 (Sample Compared to 1), it was confirmed that the AC breakdown voltage and temperature characteristics were improved. It was also confirmed that the relative dielectric constant was better than when x was 0.40 (Sample 8).

  From sample 4, 11-17, when y (content of Sr) in the composition formula of the first main composition is 0.001 ≦ y ≦ 0.100 (sample 4, 12-16), y is It was confirmed that the relative dielectric constant was better than 0, that is, when the first main composition did not contain Sr (sample 11). In addition, it was confirmed that relative permittivity and temperature characteristics were improved as compared with the case where y in the composition formula was 0.155 (sample 17).

  From Samples 21 to 27, when a (Sn content) in the composition formula of the first main composition is 0 and z (Zr content) is 0.04 ≦ z ≦ 0.20 (Samples 22 to 26) ), It was confirmed that relative permittivity, dielectric loss, AC breakdown voltage and temperature characteristics were improved as compared with the case where z was 0.03 (sample 21). In addition, it was confirmed that relative permittivity and temperature characteristics were improved as compared with the case where z in the composition formula was 0.25 (sample 27).

  From samples 28 to 31, when z in the composition formula of the first main composition is 0 and a is 0.04 ≦ a ≦ 0.20 (samples 28 to 30), when a is 0.25 (sample Compared to 31), it was confirmed that the relative dielectric constant, the AC breakdown voltage, and the temperature characteristics were improved.

  From Samples 4, 21, 22, 32-36, when z + a in the composition formula of the first main composition is 0.04 ≦ z + a ≦ 0.30 (samples 4, 22, 32-35), z + a is 0. It was confirmed that relative permittivity, dielectric loss, AC breakdown voltage, and temperature characteristics were improved as compared with 0.03 (sample 21). In addition, it was confirmed that relative permittivity and temperature characteristics were improved as compared with the case where z + a in the composition formula was 0.40 (sample 36).

  From samples 4, 41 to 43, when α in the composition formula of the second main composition is 0.00 ≦ α ≦ 0.100 (samples 4, 41, and 42), when α is 0.150 (sample Compared to 43), it was confirmed that the relative dielectric constant and temperature characteristics were improved.

  From the samples 4, 51 to 56, when the ratio A (parts by weight) of the second main composition to the weight of the entire main composition (weight of the main component) is 5.00 ≦ A ≦ 40.00 (samples 4, 53 ~ 55), it was confirmed that the temperature characteristics were better than in the case of the conventional BCTZ system not containing the second main composition (sample 51) and in the case where A was 4.00 (sample 52). . It was also confirmed that the relative dielectric constant was better than when A was 50.00 (sample 56).

  From Samples 4, 61 to 66, m in the composition formula of the first main composition, n in the composition formula of the second main composition, and A is 0.97 ≦ {(100−A) × m + A × n}. When x 0.01 ≦ 1.03 is satisfied (sample 4, 62 to 65), the ratio of {(100−A) × m + A × n} × 0.01 is 0.96 (sample 61). It was confirmed that the dielectric constant and the AC breakdown voltage were good. In addition, when {(100−A) × m + A × n} × 0.01 was 1.04 (sample 66), the sinterability deteriorated.

  Samples 71 to 137 are samples in which the subcomponent content of sample 4 is changed.

  Samples 71 to 75 are samples in which the content of zinc oxide as the second subcomponent is changed. All of the samples were confirmed to have good characteristics.

  Samples 81 to 86 are samples in which the content of bismuth oxide, which is the first subcomponent, is changed. It was confirmed that the samples 82 to 85 changed between 0.30 to 3.00 parts by weight with respect to 100 parts by weight of the main component have better temperature characteristics than the sample 81 having 0.20 parts by weight. did it. In addition, it was confirmed that the relative dielectric constant, the AC breakdown voltage, and the temperature characteristics were improved as compared with the sample 86 having 4.00 parts by weight.

  Samples 91 to 107 are samples in which the type and / or content of the third subcomponent is changed from that of the sample 4. It was confirmed that all of the samples 91 to 98 in which the type of the third subcomponent was changed and the sample 99 containing two types of the third subcomponent had good characteristics.

It is confirmed that all of the samples 101 to 107 that do not contain the third subcomponent and the samples 102 to 107 in which the content of the _third subcomponent (Nd ₂ O ₃ ) is changed from the sample 4 have good characteristics. did it.

 Samples 4, 91 to 99, and 102 to 107 containing 0.005 to 0.300 parts by weight of the third subcomponent may have better AC breakdown voltage than Sample 101 that does not contain the third subcomponent. It could be confirmed.

  Samples 111 to 128 are samples in which the type and / or content of the fourth subcomponent is changed from that of sample 4. All of the samples were confirmed to have good characteristics.

  It was confirmed that Samples 4 and 112 to 128 containing 0.02 to 1.50 parts by weight of the fourth subcomponent had better AC breakdown voltage than Sample 111 containing no fourth subcomponent.

  Samples 131 to 137 are samples in which the type and / or content of the fifth subcomponent is changed from the sample 4. All of the samples were confirmed to have good characteristics.

  It was confirmed that the samples 4 and 132 to 137 containing 0.01 to 0.60 parts by weight of the fifth subcomponent had better reliability than the sample 131 containing no fifth subcomponent.

  From the results of EPMA (FIG. 2), the dielectric ceramic composition according to the present invention is composed of a first main composition 12 whose main composition is a BCTZ-based dielectric ceramic composition, and a BT-based dielectric ceramic composition. It was confirmed that the composition was composed of two main compositions, a second main composition 14 made of a product. At the same time, it was confirmed that the main composition of the dielectric ceramic composition according to the present invention was not a single type of main composition.

 Regarding the subcomponent, it was confirmed that the first subcomponent bismuth oxide was mostly dissolved in the first main composition 12. It was confirmed that the zinc oxide as the second subcomponent was contained in the grain boundary (not shown) and the other composition 16.

2 ... Ceramic capacitor 4 ... Dielectric 6, 8 ... Electrode 12 ... First main composition 14 ... Second main composition 16 ... Other compositions

Claims (8)

And _{(Ba 1-x-y,} Ca x, Sr y) m (Ti 1-z-a, Zr z, Sn a) a first main composition represented by the composition formula of _{O 3,}
A second main composition represented by a composition formula of (Ba _1-α , Sr _α ) _n TiO ₃ ;
A dielectric ceramic composition comprising a first subcomponent comprising bismuth oxide,
0.01 ≦ x ≦ 0.30
0 <y ≦ 0.1
0.04 ≦ z ≦ 0.2
0 ≦ a ≦ 0.2
0.04 ≦ z + a ≦ 0.3
0 ≦ α ≦ 0.1
And
The sum of the content of the first main composition and the content of the second main composition is 100 parts by weight, the content of the second main composition is A parts by weight, and the content of the first subcomponent Is ₁ part by weight of B,
5 ≦ A ≦ 40
0.97 ≦ {(100−A) × m + A × n} × 0.01 ≦ 1.03
0.3 ≦ B ₁ ≦ 3
A dielectric porcelain composition comprising:   The dielectric ceramic composition according to claim 1, wherein 5 ≦ A ≦ 30. The dielectric ceramic composition according to claim _{1, wherein} 0.3 ≦ B ₁ ≦ 1.5. When the second subcomponent consisting of zinc oxide is contained and the content of the second subcomponent is B ₂ parts by weight,
The dielectric ceramic composition according to claim 1, wherein 0.45 ≦ B ₂ ≦ 10. A third subcomponent comprising at least one oxide selected from the group consisting of La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, and Y, and the content of the third subcomponent being an oxide When converted to ₃ parts by weight of B,
The dielectric ceramic composition according to claim 1, wherein 0 <B ₃ ≦ 0.3. A fourth subcomponent composed of at least one oxide selected from the group consisting of Al, Ga, Si, Mg, In, and Ni. The content of the fourth subcomponent is ₄ parts by weight in terms of oxide. If
The dielectric ceramic composition according to claim 1 is 0.02 ≦ _{B 4} ≦ 1.5. When the fifth subcomponent consisting of at least one oxide in the group consisting of Mn and Cr is contained, and the content of the fifth subcomponent is ₅ parts by weight in terms of oxide,
The dielectric ceramic composition according to claim 1, wherein 0.01 ≦ B ₅ ≦ 0.6.   The electronic component containing the dielectric ceramic composition in any one of Claims 1-7.

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