JP2021054686A - Dielectric composition and electronic component - Google Patents

Abstract

To provide a dielectric composition exhibiting a high density and a relatively high relative dielectric constant even when being fired at a low temperature, and an electronic component comprising a dielectric layer composed of the dielectric composition.SOLUTION: The dielectric composition according to the present invention is composed of a main phase particle and at least one segregated phase selected from an Mn-Ca-based segregated phase, an Al-based segregated phase and a Mn-Al-based segregated phase. The main phase particle contains a composite oxide as a main component, represented by a general formula ABO3, and A is one or more selected from calcium and strontium, and B contains at least zirconium. Further, the Mn-Ca-based segregated phase contains an Mn-Ca-based composite oxide having calcium and manganese, the Al-based segregated phase contains an Al-based composite oxide having calcium or/and strontium and aluminum, and the Mn-Al-based segregated phase contains a Mn-Al-based composite oxide having manganese and aluminum.SELECTED DRAWING: Figure 2

Description

The present invention relates to a dielectric composition and an electronic component comprising a dielectric layer composed of the dielectric composition.

Electronic circuits or power supply circuits incorporated in electronic devices are equipped with a large number of electronic components such as multilayer ceramic capacitors that utilize the dielectric properties exhibited by dielectrics. Such as an electronic component material constituting a dielectric (dielectric material), (Ca, Sr) (Zr , Ti, Hf) O 3 based dielectric compositions are known.

The dielectric composition is co-fired together with an internal electrode composed of a conductive metal when the above electronic component is manufactured. The dielectric composition obtained through this firing step is required to have a high sintering density. This is because if the density of the dielectric composition is insufficient, deterioration of moisture resistance and structural defects may occur.

Patent Document 1, (Ca, Sr) ( Zr, Ti, Hf) in the main phase particles _{O 3} system, and calcined by adding a MnCO ₃ powder and SiO ₂ powder to form a segregation phase of Si and Mn dielectric The body composition is disclosed. However, the present inventors have clarified that it is not possible to secure a sufficient density as a sintered body only by forming segregated phases of Si and Mn. In fact, in Patent Document 1, the sinterability is ensured by additionally adding a plurality of sintering aids such as _{Li 2} O and B ₂ O ₃ in addition to the above-mentioned sub-components.

Japanese Unexamined Patent Publication No. 2004-217509

The present invention has been made in view of such circumstances, and an object of the present invention is a dielectric composition exhibiting a high density and a relatively high relative permittivity, and a dielectric layer composed of the dielectric composition. Is to provide an electronic component equipped with.

In order to achieve the above object, the dielectric composition according to the present invention is
With the main phase particles
It has an Mn—Ca based segregation phase, an Al segregation phase, and at least one segregation phase selected from the Mn—Al based segregation phase.
The main phase particles contain a composite oxide represented by the _{general formula ABO 3 as a main component.}
The A is one or more selected from calcium and strontium, and is
B contains at least zirconium and contains at least zirconium.
The Mn-Ca-based segregated phase contains a Mn-Ca-based composite oxide having calcium and manganese.
The Al-based segregated phase contains an Al-based composite oxide having calcium and / and strontium and aluminum.
The Mn—Al segregated phase contains a Mn—Al composite oxide having manganese and aluminum.

The present inventors have conducted intensive studies and as a result, (Ca, Sr) (Zr , Ti, Hf) in _{O 3} based dielectric compositions, between the particles of the main phase grains, as shown above, Mn-Ca It has been found that the presence of at least one segregation phase selected from the system-based segregation phase, the Al-based segregation phase, and the Mn—Al-based segregation phase increases the density of the sintered body.

As the segregation phase, all of the above three types of segregation phases (Mn—Ca-based segregation phase, Al-based segregation phase, and Mn—Al-based segregation phase) may be present. In this case, the density of the dielectric composition is particularly high.

Further, the dielectric composition according to the present invention exhibits a relatively high relative permittivity as compared with the case where the above-mentioned segregated phase does not exist and the case where it has a segregated phase of Si and Mn.

In the dielectric composition according to the present invention, when the Mn—Ca based segregated phase is present as the segregated phase, the Mn—Ca based composite oxide is represented by the composition formula (Ca, Mn) O. The Mn—Ca-based composite oxide can include both a composite oxide having an atomic number ratio of Ca and Mn of Ca <Mn and a composite oxide having a Ca ≧ Mn ratio. As a result, the dielectric composition according to the present invention has a higher density and a relatively higher relative permittivity.

When the Mn-Ca-based segregated phase is present, the strontium content in the Mn-Ca-based segregated phase is 1 mol or less, assuming that the sum of the contents of calcium, manganese, and strontium is 100 mol. Is preferable. As a result, the dielectric composition according to the present invention has a higher density and a relatively higher relative permittivity.

The crystal structure of the Mn—Ca segregated phase is preferably cubic.

In the dielectric composition according to the present invention, when the Al-based segregated phase is present as the segregated phase, the Al-based composite oxide is represented by the composition formula (Ca, Sr) Al _{c Od} . The Al-based composite oxide includes a composite oxide having an atomic number ratio (c / d) of aluminum and oxygen of 12/19, a composite oxide having a c / d of 4/7, and c / d. It can contain at least one selected from composite oxides having a value of 2/4. As a result, the dielectric composition according to the present invention has a higher density and a relatively higher relative permittivity.

When the Al-based segregated phase is present, assuming that the sum of the contents of calcium, strontium, aluminum, and zirconium in the Al-based segregated phase is 100 mol parts, the zirconium content is 0 to 30 mol parts. Is preferable. As a result, the dielectric composition according to the present invention has a higher density and a relatively higher relative permittivity.

Further, the crystal structure of the Al-based segregated phase is preferably any one of hexagonal, monoclinic, and tetragonal, and more preferably hexagonal.

Further, in the dielectric composition according to the present invention, when the Mn—Al based segregated phase is present as the segregated phase, the Mn—Al composite oxide is the composite oxide represented by the composition formula MnAl ₂ O _4. Is preferable. The presence of the Mn—Al segregated phase as described above increases the density of the sintered body and provides a relatively high relative permittivity.

In the dielectric composition according to the present invention, the ratio (A2 / A1) of the total cross-sectional area (A2) of the segregated phase to the cross-sectional area (A1) of the dielectric composition in an arbitrary cross section of the dielectric composition. ) Is preferably 0.001 to 0.1, more preferably 0.005 to 0.1, and even more preferably 0.01 to 0.1. The segregated phase includes a Mn—Ca segregated phase, an Al segregated phase, and an Mn—Al segregated phase. Within this area ratio, the density of the dielectric composition is particularly improved and a relatively higher relative permittivity is obtained.

The dielectric composition according to the present invention can be applied to electronic components including a dielectric layer. Specific examples of the electronic component include a ceramic capacitor and a filter, and the electronic component is particularly suitable for a multilayer ceramic capacitor.

FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is an enlarged schematic view of a cross section of the dielectric composition according to the embodiment of the present invention.

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

(1. Multilayer ceramic capacitor)
(1.1 Overall configuration of multilayer ceramic capacitor)
A monolithic ceramic capacitor 1 as an example of an electronic component according to this embodiment is shown in FIG. The multilayer ceramic capacitor 1 has an element main body 10 having a structure in which a dielectric layer 2 and an internal electrode layer 3 are alternately laminated. A pair of external electrodes 4 that conduct with the internal electrode layers 3 alternately arranged inside the element body 10 are formed at both ends of the element body 10. The shape of the element body 10 is not particularly limited, but is usually a rectangular parallelepiped shape. Further, the size of the element main body 10 is not particularly limited, and may be an appropriate size depending on the application.

(1.2 Dielectric layer)
The dielectric layer 2 is composed of the dielectric composition according to the present embodiment, which will be described later. The thickness of the dielectric layer 2 per layer (interlayer thickness) is not particularly limited, and can be arbitrarily set according to desired characteristics, applications, and the like. Usually, the interlayer thickness is preferably 30 μm or less, more preferably 20 μm or less, and further preferably 10 μm or less. The number of laminated dielectric layers 2 is not particularly limited, but in the present embodiment, it is preferably 10 or more, for example.

(1.3 Internal electrode layer)
As shown in FIG. 1, in the present embodiment, the internal electrode layer 3 is laminated so that the ends of the internal electrode layer 3 are alternately exposed on the two opposing end faces of the element body 10.

The main component of the conductive material contained in the internal electrode layer 3 may be a noble metal or a base metal. However, since precious metals are expensive, it is preferable to use relatively inexpensive base metals as the main component of the conductive material.

In particular, in the present embodiment, since the constituent material of the dielectric layer 2 has reduction resistance, a base metal can be preferably used as the main component of the conductive material. The main component is a component that accounts for 80% by mass or more of the conductive material contained in the internal electrode layer 3.

The noble metal is not particularly limited, and examples thereof include Pd, Pt, and Ag-Pd alloys, and known conductive materials can be used. The base metal is not particularly limited, and for example, Ni, Ni-based alloys and the like can be exemplified, and a known conductive material may be used.

The Ni and Ni-based alloys described above may contain various trace components such as P and S in an amount of about 0.1% by mass or less. Further, the internal electrode layer 3 may contain a constituent material of the dielectric layer 2 as a co-material, or may be formed by using a commercially available electrode paste. The thickness of the internal electrode layer 3 may be appropriately determined according to the application and the like.

(1.4 External electrode)
The conductive material contained in the external electrode 4 is not particularly limited. For example, known conductive materials such as Ni, Cu, Sn, Ag, Pd, Pt, Au, alloys thereof, and conductive resins may be used. The thickness of the external electrode 4 may be appropriately determined according to the application and the like.

(2. Dielectric composition)
As shown in FIG. 2, the dielectric composition constituting the dielectric layer 2 according to the present embodiment has a main phase particle 14 and an segregated phase 16.

(2.1 Main phase particles)
The main phase grains 14 shown in FIG. 2 includes a composite oxide represented by the composition formula _{(Ca 1-x Sr x)} m (Zr 1-y-z Ti y Hf z) O 3 as a main component. In the above composition formula, the amount of oxygen (O) may be slightly deviated from the above stoichiometric composition.

In the above composition formula, x indicating the ratio of calcium (Ca) and strontium (Sr) can be 0 ≦ x ≦ 1.0. That is, the ratio of Ca and Sr is arbitrary, and only one of them may be contained. In the present embodiment, the absolute values of the capacitance temperature coefficient and the relative permittivity can be arbitrarily controlled based on the ratio of Ca and Sr.

Further, in the above composition formula, y represents the number of atoms of titanium (Ti) and z represents the number of atoms of hafnium (Hf). y + z is not particularly limited, but can be, for example, 0 ≦ y + z ≦ 0.1. The above-mentioned composite oxide, which is the main component, _{mainly contains ZrO 2 which is more difficult to reduce than TiO 2} , so that the reduction resistance of the dielectric composition tends to increase.

Further, in the above composition formula, m can be 0.8 ≦ m ≦ 1.3, preferably 1.00 ≦ m ≦ 1.05. By setting the ratio of (Ca, Sr) to (Zr, Ti, Hf) within the above range, it is possible to prevent the dielectric composition from becoming a semiconductor even when it is fired in a reducing atmosphere.

In addition to the main component described above, the main phase particle 14 contains subcomponents such as vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), and tungsten (W). Can be included.

In the cross section of the dielectric composition shown in FIG. 2, the equivalent circle diameter of the main phase particles 14 is preferably in the range of 0.1 μm to 5 μm on average.

(2.2 Segregation phase)
In the dielectric composition according to the present embodiment, as shown in FIG. 2, the segregated phase 16 is present between the particles of the main phase particles 14. As the segregation phase 16, there may be an Mn—Ca based segregation phase 16a, an Al based segregation phase 16b, and an Mn—Al based segregation phase 16c. FIG. 2 presents a dielectric composition having all of the above three segregation phases 16a to 16c. However, in the present embodiment, at least one of the above three segregation phases 16a to 16c may be present. Hereinafter, the characteristics of each segregation phase 16a to 16c will be described.

First, the characteristics of the Mn—Ca based segregation phase 16a will be described. The Mn—Ca based segregation phase 16a contains at least an Mn—Ca based composite oxide having calcium (Ca) and manganese (Mn). The Mn—Ca-based composite oxide is represented by the composition formula (Ca, Mn) O. In this Mn—Ca-based composite oxide, the ratio of Ca and Mn may be a≈b or a <b, where a is the number of atoms of Ca and b is the number of atoms of Mn. , A> b. In the present embodiment, the Mn—Ca-based composite oxide preferably contains both a composite oxide in which the ratio of Ca and Mn is a <b and a composite oxide in which a ≧ b.

The Mn—Ca based segregation phase 16a may contain Sr, Zr, Ti and the like as impurities. In the Mn—Ca segregated phase 16a, assuming that the sum of the contents of Ca, Mn and impurities is 100 mol parts, the content of the impurities is preferably 2 mol parts or less. In particular, the content of Sr in the Mn—Ca segregated phase 16a is preferably 1 mol part or less.

In the present embodiment, the crystal structure of the Mn—Ca based segregated phase 16a is preferably cubic. Further, in the cross section of the dielectric composition shown in FIG. 2, the circle-equivalent diameter (mean value) of the Mn—Ca segregated phase 16a is 1/20 of the circle-equivalent diameter (mean value) of the main phase particles 14. The size is preferably about 1/2. More specifically, it is preferably in the range of 0.005 μm to 0.5 μm.

Next, the features of the Al-based segregation phase 16b will be described. The Al-based segregation phase 16b contains an Al-based composite oxide having calcium (Ca) and / and strontium (Sr) and aluminum (Al).

The Al-based composite oxide is represented by the composition formula (Ca, Sr) Al _{c Od} , and is a composite oxide in which the atomic number ratio (c / d) of aluminum and oxygen is 12/19, and c / d is 4 /. It contains at least one selected from a composite oxide having a c / d of 7 and a composite oxide having a c / d of 2/4. More specific types of Al-based composite oxides include, for example, CaAl ₁₂ O ₁₉ , CaAl ₄ O ₇ , CaAl ₂ O ₄ , SrAl ₁₂ O ₁₉ , SrAl ₄ O ₇ , SrAl ₂ O ₄ , (Ca, Sr). ) Al ₁₂ O ₁₉ , (Ca, Sr) Al ₄ O ₇ , and (Ca, Sr) Al ₂ O _{4 and the} like are exemplified.

Further, the Al-based segregation phase 16b may contain Zr, Ti, Hf, Mn and the like as impurities. In the Al-based segregation phase 16b, assuming that the sum of the contents of Ca, Sr, Al and impurities is 100 mol parts, the content of the impurities is preferably 35 mol parts or less. In particular, the content of Zr in the Al-based segregated phase 16b is preferably in the range of 0 to 30 mol parts.

In the present embodiment, the crystal structure of the Al-based segregated phase 16b is preferably any one of hexagonal, monoclinic, and tetragonal, and more preferably hexagonal. Further, in the cross section of the dielectric composition shown in FIG. 2, the circle-equivalent diameter (mean value) of the Al-based segregation phase 16b is 1/20 to 1 with respect to the circle-equivalent diameter (mean value) of the main phase particles 14. The size is preferably about / 2. More specifically, it is preferably in the range of 0.005 μm to 0.5 μm.

Next, the characteristics of the Mn—Al based segregation phase 16c will be described. The Mn—Al based segregation phase 16c contains a Mn—Al composite oxide having manganese (Mn) and aluminum (Al). More specifically, the Mn—Al composite oxide is preferably a spinel-type composite oxide represented by _{the composition formula MnAl 2} O _4. When MnAl ₂ O ₄ is contained, the crystal structure of the Mn—Al based segregation phase 16c is cubic.

The Mn—Al based segregation phase 16c may contain Ca, Sr, Zr and the like as impurities. In the Mn—Al segregated phase 16c, assuming that the sum of the contents of Mn, Al and impurities is 100 mol parts, the content of the impurities is preferably 20 mol parts or less.

Further, in the cross section of the dielectric composition shown in FIG. 2, the circle-equivalent diameter (mean value) of the Mn—Al-based segregation phase 16c is 1/20 of the circle-equivalent diameter (mean value) of the main phase particles 14. The size is preferably about 1/2. More specifically, it is preferably in the range of 0.005 μm to 0.5 μm.

As described above, in the present embodiment, at least one selected from the above three segregation phases 16a to 16c may be formed between the particles of the main phase particles 14. However, among the three types of segregation phases 16a to 16c, it is particularly preferable that the Mn—Ca based segregation phase 16a is formed.

In the cross section of the dielectric composition shown in FIG. 2, the total cross-sectional area of the segregated phase 16 is preferably within a predetermined ratio range. Specifically, in an arbitrary cross section represented by L1 × L2, the cross-sectional area of the dielectric composition is A1 (that is, A1 = L1 × L2), and all the segregated phases 16a to 16c contained in the cross section are cut off. Assuming that the total area is A2, A2 / A1 is preferably 0.001 to 0.1, more preferably 0.005 to 0.1, and 0.01 to 0.1. Is even more preferable.

When all the segregation phases 16a to 16c are included, the content ratio of each segregation phase 16a to 16c is arbitrary and is not particularly limited. For example, in an arbitrary cross section of the dielectric composition, the cross-sectional area of the Mn—Ca segregated phase 16a is Sa, the cross-sectional area of the Al segregated phase 16b is Sb, and the cross-sectional area of the Mn—Al segregated phase 16c is Sc. (That is, A2 = Sa + Sb + Sc), the ratio of Sa, Sb, and Sc can be 4: 2: 1. When all the segregated phases 16a to 16c are included, the ratio (Sa / A2) of the cross-sectional area Sa of the Mn—Ca based segregated phase 16a to the total cross-sectional area A2 of all the segregated phases 16a to 16c is 0.3. It is preferably in the range of ~ 1.0.

In this embodiment, the content of silicon (Si) in the dielectric composition is preferably 5 mol parts or less. In this embodiment (Ca, Sr) (Zr, Ti, Hf) in the dielectric composition of the _{O 3} system, without free of Si compound, that there are three kinds of segregated phases 16a~16c described above , A dielectric composition having a high density can be obtained.

In the present embodiment, the method for determining whether or not the dielectric composition constituting the dielectric layer 2 contains the segregated phases 16a to 16c is not particularly limited, but for example, the following method can be applied.

First, a cross section of the dielectric composition is photographed using a transmission electron microscope (TEM) to obtain a bright field (BF) image. At this time, a sample for TEM observation is obtained by preparing a thin piece of the dielectric layer 2 by a microsampling method using a focused ion beam (FIB). The width of the field of view for photographing is not particularly limited, but is, for example, about 0.1 × 0.1 μm to 10 × 10 μm square. In this bright-field image, a region having a contrast different from that of the composite oxide particles 14 is recognized as being out of phase. Whether or not they have different contrasts, that is, whether or not they have different phases, may be determined visually, or may be determined by software or the like that performs image processing.

Then, regarding the above-mentioned different phases, each element contained in the different phases such as manganese (Mn), aluminum (Al), calcium (Ca), strontium (Sr), and zirconium (Zr) is measured by electron probe microanalyzer (EPMA). Measure the content.

In the present embodiment, when the total content of the main elements (excluding oxygen) contained in the different phase is 100 mol parts and the total content of Ca and Mn is 98 mol parts or more, the different phase is Mn-. It is determined that the phase is a Ca-based segregated phase 16a. On the other hand, when the content of Mn contained in the different phase is 20 mol parts or less and the Al content is 50 mol parts or more, it is determined that the different phase is the Al-based segregated phase 16b. .. When the total content of Mn and Al contained in the different phase is 80 mol parts or more, it is determined that the different phase is the Mn—Al based segregated phase 16c.

In the above-mentioned analysis of the different phases, it is preferable to perform the measurement of the element content by the point analysis and the measurement of the element mapping image by the surface analysis in combination. Further, the circle-equivalent diameter of each segregation phase 16a to 16c and the total cross-sectional area ratio (A2 / A1) of the segregation phase 16 are image-analyzed from a cross-sectional photograph taken by a scanning transmission electron microscope (STEM) or TEM. It can be calculated by

In order to more accurately identify the composite oxide contained in each segregated phase 16a to 16c (identify the compound), it is preferable to perform crystal structure analysis by electron diffraction during the above TEM observation. The crystal system of each segregated phase 16a to 16c can also be grasped by the analysis.

(3. Manufacturing method of multilayer ceramic capacitor)
Next, an example of a method for manufacturing the multilayer ceramic capacitor 1 shown in FIG. 1 will be described below. In the following description, a production method will be described when all the segregated phases 16a to 16c are present in the dielectric composition.

First, the dielectric composition raw material contained in the dielectric paste is prepared. As the raw material for the dielectric composition, a main component raw material that mainly constitutes the main phase particles 14 and an Mn—Ca-based composite oxide powder, an Al-based composite oxide powder, and an Mn—Al composite oxide powder are used. prepare.

The main component material, it is possible to use a powder of a composite oxide represented by a composition formula _{(Ca 1-x Sr x)} m (Zr 1-y-z Ti y Hf z) O 3. As the main component material, it is also possible to use the above (Ca, Sr) (Zr, Ti, Hf) O 3 based oxide of each metal contained in the composite oxide.

When preparing the main component material in the form of complex oxides, (Ca, Sr) (Zr , Ti, Hf) O 3 composite oxide may be produced by so-called solid phase method, other liquid phase It may be produced. In the case of the solid phase method, for example, strontium carbonate (SrCO ₃ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), titanium oxide (TIO ₂ ), and hafnium oxide (HfO ₂ ) are used as raw materials. Is weighed at a predetermined ratio, mixed, calcined, and pulverized if necessary to prepare a powder of composite oxide. On the other hand, in the liquid phase method, a composite oxide powder is obtained by a known method such as a hydrothermal synthesis method or a sol-gel method.

When applying the solid phase method, the detailed conditions for calcining are not particularly limited, and known conditions may be adopted. Further, the average particle size of the main component raw material can be controlled by the pulverization conditions, and is preferably about 0.1 to 1 μm in the state before being made into a paint.

In the present embodiment, in addition to the main component raw material, three types of powders such as Mn-Ca-based composite oxide powder, Al-based composite oxide powder, and Mn-Al composite oxide powder are prepared. In addition, these three kinds of powders mainly constitute Mn-Ca-based segregation phase 16a, Al-based segregation phase 16b, and Mn-Al-based segregation phase 16c in the dielectric composition after the main firing, respectively.

The powder of the Mn-Ca-based composite oxide can _{be obtained by mixing calcium carbonate (CaCO 3} ) and manganese carbonate (MnCO ₃ ) in a predetermined compounding ratio, pre-baking, and then pulverizing the powder. The composition of the Mn—Ca-based composite oxide powder can be controlled by adjusting the above-mentioned compounding ratio.

The Al-based composite oxide powder is _{prepared by mixing at least one selected from calcium carbonate (CaCO 3} ) and strontium carbonate (SrCO ₃ ) and aluminum oxide (Al ₂ O ₃ ) in a predetermined blending ratio and baking. After that, it is obtained by crushing it. The composition of the Al-based composite oxide powder can be controlled by the blending ratio of each raw material, as in the case of the Mn—Ca-based composite oxide powder.

The powder of the Mn—Al composite oxide is _{obtained by mixing aluminum oxide (Al 2} O ₃ ) and manganese carbonate (MnCO ₃ ) in a predetermined compounding ratio, calcining the mixture, and then pulverizing the mixture. The composition of the Mn—Al composite oxide powder can be controlled by the blending ratio of each raw material in the same manner as described above.

The calcining conditions for the above three types of composite oxide powders (Mn-Ca-based composite oxide, Al-based composite oxide, and Mn-Al composite oxide) may be the same as those for the above-mentioned main component raw materials. However, preferably, the heating rate is 50 to 500 ° C./hour, and the temporary firing temperature is 600 ° C. to 1200 ° C. Further, in the above step, as a pulverization method, a method such as a roller mill, a jet mill, an attritor, a ball mill, or a bead mill can be applied, and the particle size of each composite oxide obtained is prepared by controlling the conditions at the time of pulverization. To do. The average particle size of each additive is preferably about 0.01 to 1 μm in the state before being made into a paint.

Subsequently, a paste for a dielectric is prepared by using the main component raw material obtained by the above step and three kinds of composite oxide powders. Specifically, a paste for a dielectric is prepared by kneading a main component raw material, three types of composite oxide powders, a binder, and a solvent at a predetermined compounding ratio to form a paint. Known materials may be used for the binder and the solvent, and the content of the binder in the dielectric paste is about 4 to 15 parts by weight, assuming that the total weight of the main component raw material and the composite oxide powder is 100 parts by weight. The content of the solvent in the dielectric paste may be about 50 to 150 parts by weight, assuming that the total weight of the main component raw material and the composite oxide powder is 100 parts by weight.

Further, the total content of the three types of composite oxide powders in the dielectric paste is preferably 0.1 to 10 parts by weight, assuming that the content of the main component raw material is 100 parts by weight. By setting the compounding ratio, the ratio (A2 / A1) of the total cross-sectional area of all the segregated phases 16a to 16c is within the range of 0.001 to 0.1 in the cross section of the dielectric composition after the main firing. It becomes. When only a part of the three segregation phases 16a to 16c is formed in the dielectric composition, the composite oxide to be added to the dielectric paste is added according to the type of segregation phase 16 to be formed. The type of powder may be changed.

Further, the dielectric paste may contain additives such as a plasticizer and a dispersant, if necessary. Further, in addition to the main component raw material and the above-mentioned three types of composite oxide powders, oxides such as V, Nb, Ta, Cr, Mo, and W may be added as subcomponents. The content of these sub-ingredients is preferably 0 to 1 part by weight with respect to 100 parts by weight of the content of the main component raw material.

The paste for the internal electrode layer is obtained by kneading a raw material of a conductive material, a binder, and a solvent. Known materials may be used for the binder and the solvent. The paste for the internal electrode layer may contain additives such as a common material, a plasticizer, and a dispersant, if necessary. The paste for the external electrode can be prepared in the same manner as the paste for the internal electrode layer.

Each of the obtained pastes is used to form a green sheet and an internal electrode pattern, which are laminated to obtain a green chip.

If necessary, the obtained green chips are subjected to a binder removal treatment. The binder removal treatment may be performed under known conditions, and for example, the holding temperature is preferably 200 to 350 ° C.

After the binder removal treatment, the green chip is finally fired to obtain the element body 10. In the present embodiment, the atmosphere at the time of the main firing may be appropriately determined according to the type of the conductive material in the paste for the internal electrode. For example, when a noble metal is used as the conductive material, it can be fired in an atmospheric atmosphere. On the other hand, when a base metal such as Ni or a Ni-based alloy is used as the conductive material, the main firing is performed in a reducing atmosphere. When firing in a reducing atmosphere, the partial pressure of oxygen in the firing atmosphere ^{is preferably 10-13} to ^10-9 MPa, and as the atmospheric gas, for example, a mixed gas of nitrogen and hydrogen is humidified and used. Is preferable.

Further, the holding temperature at the time of the main firing can be 1200 ° C. to 1400 ° C.

Other than the above conditions, the heating rate is preferably 50 to 500 ° C./hour, the holding time is preferably 0.5 to 8 hours, and the cooling rate is preferably 50 to 500 ° C./hour. ..

After the main firing, the obtained element body 10 is subjected to a reoxidation treatment (annealing), if necessary. The reoxidation treatment is a treatment for reoxidizing the dielectric layer, and the conditions of the reoxidation treatment are, for example, an oxygen partial pressure higher than that at the time of main firing, and a holding temperature higher than 600 ° C. It is preferably less than 1100 ° C.

The dielectric composition constituting the dielectric layer 2 of the element body 10 obtained as described above is the above-mentioned dielectric composition. The end face of the element body 10 is polished, a paste for an external electrode is applied and baked to form an external electrode 4. Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.

In this way, the monolithic ceramic capacitor 1 according to this embodiment is manufactured.

(4. Summary of this embodiment)
In the present embodiment, the raw material of the dielectric composition contains at least one of the above-mentioned Mn—Ca-based composite oxide powder, Al-based composite oxide powder, and Mn—Al composite oxide powder. Thereby, in the present embodiment, it is considered that the sintering of the dielectric composition is more preferably promoted at the time of the main firing than in the conventional case.

The principle of increasing the density is not always clear, but for example, three types of composite oxides in which the main elements (Ca, Sr, Zr, etc.) contained in the main phase particles 14 are present between the main phase particles 14. It is considered that the density is improved by diffusing into (that is, diffusing into each segregated phase 16a to 16c) and promoting element diffusion between the main phase particles. In particular, the phenomenon that Mn and Ca in the Mn-Ca-based composite oxide are replaced with Ca in the main phase particles, or Ca or Sr in the Al-based composite oxide is Ca or Ca in the main phase particles 14. It is presumed that the phenomenon of being replaced by Sr is occurring.

Conventionally, a technique for forming segregation of MnO, segregation of Si and Mn, etc. in a dielectric composition has been known. However, it is not possible to secure a sufficient sintering density only with these segregated phases, and conventionally, as a sintering aid, SiO ₂ , B ₂ O ₃ , Li ₂ O, CuO, (Ba, Ca) The sintering density was secured by additionally adding _{SiO 3 and the like.} Depending on the amount of these sintering aids added, the relative permittivity may decrease. In addition, when B ₂ O ₃ and Li ₂ O are added, these oxides are likely to volatilize during firing, so that voids are likely to occur in the dielectric composition. In addition, volatile B ₂ O ₃ or Li ₂ O contaminates the equipment, causing manufacturing problems.

In the present embodiment, at least one of the above-mentioned Mn-Ca-based segregation phase 16a, Al-based segregation phase 16b, and Mn-Al-based segregation phase 16c is present between the particles of the main phase particles 14. Due to the presence of these segregated phases, in the present embodiment, a dielectric composition having a high density without the addition of additional sintering aids such as _{B 2} O ₃ , Li ₂ O, and (Ba, Ca) SiO _3. You get things. In particular, the dielectric composition of the present embodiment can secure a sufficient density even when fired at a relatively low temperature of about 1200 ° C. Further, the dielectric composition of the present embodiment exhibits a relatively high relative permittivity as compared with the case where the segregated phases 16a to 16c are absent and the case where the segregated phases of Si and Mn are present.

Further, in the present embodiment, the ratio of the total cross-sectional areas (A2 / A1) of all the segregated phases 16a to 16c in any cross section of the dielectric composition is preferably 0.001 to 0.1, more preferably 0.001 to 0.1. Is 0.005 to 0.1, more preferably 0.01 to 0.1. When the proportion of the segregated phase 16 in the cross section is within the above range, the density of the dielectric composition is particularly improved, and a relatively higher relative permittivity can be obtained.

In the present embodiment, when the Mn—Ca based segregation phase 16a is present between the particles of the main phase particles 14, the Mn—Ca based segregation phase 16a preferably has the following characteristics.

The Mn—Ca segregated phase 16a preferably contains both a composite oxide in which the atomic number ratio of Ca and Mn is Ca <Mn and a composite oxide in which Ca ≧ Mn. As a result, the dielectric composition according to the present invention has a higher density and a relatively higher relative permittivity.

Further, when the sum of the contents of calcium, manganese and strontium in the Mn—Ca segregated phase 16a is 100 mol parts, the strontium content is preferably 1 mol part or less. By controlling the content of strontium in the Mn—Ca segregated phase 16a within the above range, a high sintering density can be obtained without lowering the relative permittivity.

In the present embodiment, when the Al-based segregation phase 16b is present between the particles of the main phase particles 14, the Al-based segregation phase 16b preferably has the following characteristics.

In the Al-based segregated phase 16b, assuming that the sum of the contents of calcium, strontium, aluminum, and zirconium is 100 mol parts, the zirconium content is preferably 0 to 30 mol parts. By controlling the content of zirconium in the Mn—Ca segregated phase 16a within the above range, a high sintering density can be obtained without lowering the relative permittivity.

(5. Modification example)
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, the case where the electronic component according to the present invention is a multilayer ceramic capacitor has been described, but the electronic component according to the present invention is not limited to the multilayer ceramic capacitor. The electronic component according to the present invention may be a single plate type ceramic capacitor in which a pair of electrodes are formed in a dielectric composition, or may be a filter or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples. In this example, a sintered sample is prepared under conditions where it is difficult to sinter so that the difference in sintering densities becomes clearer. Therefore, the values of the sintering density and the relative permittivity shown in the experimental results do not show preferable values as absolute values, but are values for performing relative evaluation of each Example and each Comparative Example described later.

(Experiment 1)
In Experiment 1, a sintered sample of the dielectric composition according to Examples 1 to 13 was prepared by changing the type of the composite oxide (additive) to be added. The sintered body sample of each example was specifically prepared by the procedure shown below.

First, as the main component material, to prepare a complex oxide powder represented by a composition formula _{(Ca 0.7 Sr 0.3) (Zr} 0.96 Ti 0.04) O 3. The composite oxide powder was obtained by blending calcium carbonate, strontium carbonate, zirconium oxide, and titanium oxide in a predetermined ratio and calcining them. At this time, the calcining was carried out by holding at a holding temperature of 900 ° C. for 2 hours in an atmospheric atmosphere. Further, the powder after calcination is pulverized by a ball mill to obtain an average particle size 0.5μm about (Ca, Sr) (Zr, Ti, Hf) a _{O 3} composite oxide powder.

In general, the smaller the particle size of the ceramic raw material, the easier it is to sinter at a low temperature. In this experiment, as the difference between the sintered density can be clearly seen, a relatively large average particle diameter of 0.5μm had hardly sintered (Ca, Sr) (Zr, Ti, Hf) O 3 composite oxide powder Experiments were performed using.

In this experiment 1, in addition to the above-mentioned main component raw materials, Mn-Ca-based composite oxide powder, Al-based composite oxide powder, and Mn-Al composite oxide powder were prepared as additives. The powders of these composite oxides were obtained by mixing oxides of metal elements or carbonic acid compounds constituting each composite oxide in a predetermined ratio and calcining them. The calcining condition at this time was a holding temperature of 900 ° C. in an atmospheric atmosphere. The powder after calcining was crushed by a ball mill.

In this experiment 1, the type of additive used in each example was changed. The composition of the additives used is shown in Table 1. In all the examples, the amount of the sintering aid added was 3.0 parts by weight with respect to 100 parts by weight of the main component raw material.

The main component raw material prepared in the above step and the additive were mixed with each other using a dispersant, and then an aqueous solution containing 6 wt% of polyvinyl alcohol resin was added as a binder to granulate the mixture in a mortar. At this time, the amount of the aqueous solution containing the polyvinyl alcohol resin added was 10 parts by mass with respect to 100 parts by mass of the mixed powder of the main component raw material and the additive. After granulation, the obtained granulated powder was passed through a 355 μm sieve and sized.

Next, the granulated powder after sizing is put into a mold of φ12 mm, temporarily press-molded at a pressure of 0.6 ton / cm2, and further press-molded at a pressure of 1.2 ton / cm2 to form a disk. A green molded product in the shape was obtained.

The obtained green molded product was main-fired in a reducing atmosphere and further subjected to annealing treatment to obtain a sintered body (dielectric composition) sample of the dielectric composition. The firing conditions were a heating rate of 200 ° C./h, a holding temperature of 1300 ° C., and a holding time of 2 hours. The atmospheric gas was a mixed gas of nitrogen and hydrogen humidified to a dew point of 20 ° C. (hydrogen concentration 3%). The annealing treatment conditions were a holding temperature of 750 ° C. and a holding time of 2 hours. The atmospheric gas was nitrogen gas humidified to a dew point of 20 ° C.

At least 10 sintered body samples were prepared for each example, and the evaluations shown below were carried out.

(TEM observation)
For the obtained sintered body sample, the segregated phase in the dielectric composition was analyzed by TEM, and the main component of the segregated phase and the crystal system of the segregated phase were identified. The sample for TEM observation was prepared by cutting out a thin piece from the cross section of the mirror-polished sintered body sample by the micro sample ring method by FIB. In addition, the main components of the segregated phase were identified by component analysis by EPMA. The crystal system of the segregated phase was identified by performing crystal structure analysis by electron diffraction. The measurement results for each example are shown in Table 1.

(Measurement of total cross-sectional area ratio (A2 / A1) of segregated phase)
The total cross-sectional area ratio (A2 / A1) of the segregated phase 16 was determined by image analysis of a cross-sectional photograph taken by STEM. In the observation by STEM, first, the cross section of the sintered body sample was analyzed by EPMA under the conditions of an acceleration voltage of 15 kV, an irradiation current of 100 nA, and an observation range of 5 × 5 μm, and the segregated phase 16 contained in the sample cross section was identified. After identifying the segregation phase 16 in this way, a bright field image of the cross section of the sintered body was taken, and the image was analyzed to calculate the total cross-sectional area ratio (A2 / A1) of the segregation phase 16. The measurement results for each example are shown in Table 1.

(Measurement of density)
The density of the sintered sample was measured as follows. First, the diameter of the obtained fired body sample was measured at three places to obtain a diameter R. Next, the thickness of the sintered body sample was measured at three places to obtain the thickness h. Obtained using R and h, was calculated a disk-shaped sintered body the volume of the sample V (= 1/4 · π · R 2 · h). Here, π indicates the pi. Subsequently, the mass m of the disk-shaped sintered body sample was measured, and m / V was calculated to obtain the density of the disk-shaped sintered body sample. The above measurements were performed on at least 3 samples for each example and the average density was determined. A density of 3.9 g / cm ³ or more is judged to be good. The measurement results are shown in Table 1.

(Measurement of relative permittivity)
The relative permittivity was measured as follows. First, an In-Ga alloy was applied to both main surfaces of the obtained sintered body sample to form a pair of electrodes, thereby obtaining a disk-shaped capacitor sample. Then, a signal having a frequency of 1 kHz and an input signal level (measurement voltage) of 1 Vrms was input to the capacitor sample with a digital LCR meter (4284A manufactured by YHP), and the capacitance at room temperature of 20 ° C. was measured. The relative permittivity (without unit) was calculated based on the thickness of the dielectric layer, the effective electrode area, and the capacitance obtained by the measurement. The higher the relative permittivity, the better. The measurement results of each example are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, a sintered sample of the dielectric composition was prepared without using an additive. The other experimental conditions were common to Examples 1 to 13, and the same evaluation as in each Example was performed. The evaluation results of Comparative Example 1 are shown in Table 1.

(Comparative Example 2)
In Comparative Example 2, Mn ₃ O ₄ was added to prepare a sintered sample of the dielectric composition. Other conditions are common to Examples 1 to 13. In Comparative Example 2, it was confirmed that MnO was segregated between the particles of the main phase particles 14. The evaluation results of Comparative Example 2 are shown in Table 1.

(Comparative Examples 3 and 4)
In Comparative Examples 3 and 4, Mn—Si composite oxide was added as an additive to prepare a sintered sample of the dielectric composition. Other conditions are common to Examples 1 to 13. In Comparative Examples 3 and 4, it was confirmed that Mn and Si segregated phases were formed between the particles of the main phase particles 14. The evaluation results of Comparative Examples 3 and 4 are shown in Table 1.

As shown in Table 1, in Comparative Example 1 in which no additive was used, a sufficient sintering density could not be secured, and the density of the sintered body sample was as low as ^{3.56 g / cm 3.} In Comparative Example 2 in which MnO was segregated and Comparative Examples 3 and 4 in which Mn and Si segregated phases were formed, the densities were slightly improved as compared with Comparative Example 1, but the sinterability was still insufficient. In the case of Comparative Examples 2 to 4, an additional sintering aid is required to secure sufficient strength as a sintered body.

On the other hand, in Examples 1 to 3, the Mn-Ca-based composite oxide containing Ca and Mn was added, and the Mn-Ca-based segregation containing the above-mentioned Mn-Ca-based composite oxide was performed between the particles of the main phase particles 14. It was confirmed that the phase 16a was present. In Examples 1 to 3, the density is sufficiently improved as compared with Comparative Examples 1 to 4. Further, the relative permittivity also shows a higher value in Examples 1 to 3 than in Comparative Examples 1 to 4. In Examples 1 to 3, it is considered that a relatively high relative permittivity was obtained by reducing the voids in the sintered body sample.

Further, in Examples 4 to 12, an Al-based composite oxide containing Ca or / and Sr and Al is added, and an Al-based segregated phase containing the above-mentioned Al-based composite oxide between the particles of the main phase particles 14. It was confirmed that 16b was present. Also in Examples 4 to 12, the density is sufficiently improved as compared with Comparative Examples 1 to 4 as in the case where the Mn—Ca based segregated phase 16a is formed. Similarly, the relative permittivity also shows a higher value in Examples 4 to 12 than in Comparative Examples 1 to 4.

Comparing Examples 4 to 12, the densities are higher in Examples 4, 7 and 10 in which the crystal system of the segregated phase is a hexagonal system. From this result, it was confirmed that the crystal structure of the Al-based segregated phase 16b is particularly preferably hexagonal.

Further, in Example 13, the Mn—Al composite oxide containing Mn and Al was added, and the Mn—Al based segregation phase 16c containing the Mn—Al composite oxide was present between the particles of the main phase particles 14. I was able to confirm that it was there. Also in Example 13, the density and the relative permittivity are improved as compared with Comparative Examples 1 to 4.

As described above, from the results of Experiment 1, the dielectric composition is obtained by the presence of any one of the Mn—Ca-based segregation phase 16a, the Al-based segregation phase 16b, and the Mn-Al-based segregation phase 16c between the particles of the main phase particles. It was confirmed that the density of the particles was improved and the relative permittivity was relatively high. Comparing Examples 1 to 13, it can be confirmed that Examples 1 to 3 in which the Mn—Ca based segregation phase 16a is present have higher densities and relative permittivity than the other Examples 4 to 13. From this result, it was found that in order to improve the sintering density, it is particularly preferable that the Mn—Ca based segregation phase 16a containing the Mn—Ca based composite oxide is present.

(Experiment 2)
In Experiment 2, two or more kinds were selected and added from the Mn-Ca-based composite oxide, the Al-based composite oxide, and the Mn-Al composite oxide, and the dielectric composition according to Examples 21 to 40 was added. A sintered sample was prepared. The composition of the added composite oxide in each example of Experiment 2 is shown in Table 2. In Experiment 2, as in Experiment 1, the total amount of the added composite oxide was 3.0 parts by weight with respect to 100 parts by weight of the main component raw material. In addition, the conditions other than the above are common to Examples 1 to 13 of Experiment 1. The evaluation results of each of Examples 21 to 40 are shown in Table 2.

As shown in Table 2, in the sintered body sample (dielectric composition) of Example 21, a composite oxide in which the atomic number ratio of Ca and Mn is Ca <Mn and a composite oxide in which Ca ≧ Mn is used. Both are present as Mn—Ca based segregation phase 16a. It was confirmed that in Example 21, the density and the relative permittivity were further improved as compared with Examples 1 to 3 in Table 1 due to the presence of two types of Mn—Ca based segregated phases 16a having different composition ratios. did it.

Further, in the sintered samples of Examples 22 to 31, an Al-based segregation phase 16b or an Mn—Al-based segregation phase 16c and an Mn—Ca-based segregation phase 16a are present. Further, in the sintered sample of Examples 32 to 40, all of the Mn—Ca-based segregation phase 16a, the Al-based segregation phase 16b, and the Mn—Al-based segregation phase 16c are present. In Examples 22 to 40, the density is further improved and the relative permittivity is also relatively high as compared with the case where the segregated phases 16a to 16c shown in Table 1 are formed as a single unit (Examples 1 to 13). I was able to confirm that.

(Experiment 3)
In Examples 51 to 54 of Experiment 3, when the Mn—Ca based segregation phase 16a is present, the content of Sr contained in the Mn—Ca based segregation phase 16a is controlled to control the sintered body of the dielectric composition. A sample was prepared. The content of Sr in the segregated phase was prepared by mixing strontium carbonate in a predetermined blending ratio when preparing a powder of Mn—Ca-based composite oxide by weighing calcium carbonate and manganese carbonate. The Sr content in each example is shown in Table 3. The experimental conditions other than the above in Examples 51 to 54 are common to Example 2 in Experiment 1.

Further, in Examples 55 to 62 of Experiment 3, when the Mn-Ca-based segregated phase 16a was present, the amount of the Mn-Ca-based composite oxide to be added was changed to change the amount of the sintered body of the dielectric composition. A sample was prepared. The experimental conditions other than the above in Examples 55 to 62 are common to Example 2 in Experiment 1. The evaluation results of Examples 51 to 62 in Experiment 3 are shown in Table 3.

In Examples 71 to 75 of Experiment 3, when the Al-based segregation phase 16b was present, the content of Zr contained in the Al-based segregation phase 16b was controlled to prepare a sintered sample of the dielectric composition. .. The content of Zr in the segregated phase is such that when calcium carbonate, strontium carbonate, aluminum oxide, etc. are mixed at a predetermined blending ratio to prepare an Al-based composite oxide powder, zirconium oxide is mixed at a predetermined blending ratio. Prepared by mixing. The Zr content in each example is shown in Table 4. Experimental conditions other than the above in Examples 71 to 75 are common to Example 10 in Experiment 1.

Further, in Examples 76 to 83 of Experiment 3, when the Al-based segregated phase 16b was present, the amount of the Al-based composite oxide to be added was changed to prepare a sintered sample of the dielectric composition. Experimental conditions other than the above in Examples 76 to 83 are common to Example 10 in Experiment 1. The evaluation results of Examples 71 to 83 in Experiment 3 are shown in Table 4.

Comparing the evaluation results of Examples 51 to 54 in Table 3, Examples 51 to 53 having an Sr content of 1 mol part or less in the segregated phase have higher densities and relative permittivity than those of Example 54. It has become. In Example 54, it is considered that the Sr element in the main phase particles was dissolved in the segregated phase more than necessary, so that the density and the relative permittivity were slightly lowered. From this result, by controlling the content of Sr contained in the Mn—Ca segregated phase 16a to 1 mol part or less, the relative permittivity is not lowered, and the relative permittivity and the density are relatively high. It was confirmed that both were satisfied.

Further, as shown in Table 3, in Examples 56 to 61, the area ratio (A2 / A1) of the segregated phase is in the range of 0.001 to 0.1. In Example 55, the area ratio (A2 / A1) is 0.001 or less, and in Example 62, the area ratio (A2 / A1) is 0.1 or more. Comparing the evaluation results of Examples 55 to 62, in Examples 56 to 61 in which the area ratio (A2 / A1) of the segregated phase is in the range of 0.001 to 0.1, both the density and the relative permittivity are suitable. It was confirmed that the value was high. Further, when the densities of Examples 56 to 61 are compared, the area ratio (A2 / A1) of the segregated phase is more preferably in the range of 0.005 to 0.1, and further in the range of 0.01 to 0.1. It was confirmed that it was preferable.

Table 4 shows the results when the Al-based segregation phase 16b is present, and the same tendency as when the Mn—Ca-based segregation phase 16a in Table 3 is present can be confirmed.

In Table 4, when the evaluation results of Examples 71 to 75 are compared, in Examples 71 to 74 in which the Zr content in the segregated phase is in the range of 0 to 30 mol parts, the density and relative permittivity are higher than those in Example 75. The rate is high. In Example 75, it is considered that the Zr element in the main phase particles was dissolved in the segregated phase more than necessary, so that the density and the relative permittivity were slightly lowered.

From this result, by controlling the content of Zr contained in the Al-based segregation phase 16b within the range of 0 to 30 mol parts, the relative permittivity does not decrease, and the relative permittivity is relatively high and high. It was confirmed that both the density and the satisfaction were satisfied.

Further, as shown in Table 4, in Examples 77 to 82, the area ratio (A2 / A1) of the segregated phase is in the range of 0.001 to 0.1. In Example 76, the area ratio (A2 / A1) is 0.001 or less, and in Example 83, the area ratio (A2 / A1) is 0.1 or more. Comparing the evaluation results of Examples 76 to 83, in Examples 77 to 82 in which the area ratio (A2 / A1) of the segregated phase is in the range of 0.001 to 0.1, both the density and the relative permittivity are suitable. It was confirmed that the value was high. Further, when the densities of Examples 77 to 82 are compared, the area ratio (A2 / A1) of the segregated phase is more preferably in the range of 0.005 to 0.1, and further in the range of 0.01 to 0.1. It was confirmed that it was preferable.

(Experiment 4)
In all embodiments described above, as the main component of the dielectric composition, using a composite oxide represented by a composition formula _{(Ca 0.7 Sr 0.3) (Zr} 0.96 Ti 0.04) O 3 And evaluated. In Experiment 4, apart from the respective embodiments, even experiment with different constituting the main component _{(Ca 1-x Sr x)} m (Zr 1-y-z Ti y Hf z) composition ratio of _{O 3} composite oxide went. That is, in the above composition formula, verification was also performed when the values of x, y, z, and m were changed. As a result, it was confirmed that the same tendency as the result shown in the examples can be obtained even when the composition ratio of the main component is changed.

1 ... Multilayer ceramic capacitor 10 ... Element body 2 ... Dielectric layer 14 ... Main phase particles 16 ... Segregation phase 16a ... Mn-Ca-based segregation phase 16b ... Al-based segregation phase 16c ... Mn-Al-based segregation phase 3 ... Internal electrode layer 4 ... External electrode

Claims (13)

With the main phase particles
It has at least one segregated phase selected from the Mn—Ca based segregated phase, the Al based segregated phase, and the Mn—Al based segregated phase.
The main phase particles contain a composite oxide represented by the _{general formula ABO 3 as a main component.}
The A is one or more selected from calcium and strontium, and is
B contains at least zirconium and contains at least zirconium.
The Mn-Ca-based segregated phase contains a Mn-Ca-based composite oxide having calcium and manganese.
The Al-based segregated phase contains an Al-based composite oxide having calcium and / and strontium and aluminum.
The Mn—Al segregated phase is a dielectric composition containing a Mn—Al composite oxide containing manganese and aluminum. The dielectric composition according to claim 1, wherein the segregated phase includes the Mn—Ca based segregated phase. The Mn-Ca-based composite oxide includes both a composite oxide in which the atomic number ratio of calcium (Ca) and manganese (Mn) is Ca <Mn and a composite oxide in which Ca ≧ Mn. Item 2. The dielectric composition according to Item 2. The dielectric composition according to claim 2 or 3, wherein in the Mn—Ca based segregated phase, assuming that the sum of the contents of calcium, manganese and strontium is 100 mol parts or less, the strontium content is 1 mol part or less. The dielectric composition according to any one of claims 2 to 4, wherein the crystal structure of the Mn—Ca segregated phase is a cubic system. The dielectric composition according to any one of claims 1 to 5, wherein the segregated phase includes the Al-based segregated phase. The Al-based composite oxide is represented by the composition formula (Ca, Sr) Al _{c Od} .
Select from composite oxides with an atomic number ratio (c / d) of aluminum to oxygen of 12/19, composite oxides with a c / d of 4/7, and composite oxides with a c / d of 2/4. The dielectric composition according to claim 6, which comprises at least one of these. The dielectric composition according to claim 6 or 7, wherein the sum of the contents of calcium, strontium, aluminum, and zirconium in the Al-based segregated phase is 100 mol parts, and the zirconium content is 0 to 30 mol parts. .. The dielectric composition according to any one of claims 6 to 8, wherein the crystal structure of the Al-based segregated phase is hexagonal. The dielectric composition according to any one of claims 1 to 9, wherein the segregated phase includes the Mn—Al-based segregated phase. The dielectric composition according to claim 10, wherein the Mn—Al composite oxide is a composite oxide represented by the composition formula MnAl ₂ O _4. In any cross section of the dielectric composition
The ratio (A2 / A1) of the total cross-sectional area (A2) of the segregated phase to the cross-sectional area (A1) of the dielectric composition is 0.001 to 0.1 according to any one of claims 1 to 11. The dielectric composition according to description. An electronic component including a dielectric layer comprising the dielectric composition according to any one of claims 1 to 12.

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