Dielectric compositions and electronic components

Abstract

To provide a novel dielectric composition that has high sintering density even when sintered at relatively low temperature and yet has high relative dielectric constant.SOLUTION: Provided is a dielectric composition containing: a main component expressed by {BaxSr(1-x)}mTa4O12; and a first subcomponent, m satisfying a relationship of 1.95≤m≤2.40. The first subcomponent includes silicon and manganese. When the content of the main component contained in the dielectric composition is set as 100 parts by mole, the content of silicon contained in the dielectric composition is 5.0 to 20.0 parts by mole in terms of SiO2, and the content of manganese contained in the dielectric composition is 1.0 to 4.5 parts by mole in terms of MnO.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a dielectric composition and an electronic component.

Background Art

[0002] For example, as shown in Patent Document 1, a dielectric composition having a high relative permittivity and containing no lead or alkali metal has been developed.

[0003] However, newly developed novel dielectric compositions have a problem that a high-density dielectric cannot be obtained unless fired at a high temperature.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of such a situation, the present invention aims to provide a novel dielectric composition having a high sintering density even when fired at a relatively low temperature and still having a high relative permittivity.

Means for Solving the Problems

[0006] The dielectric composition according to the first aspect of the present invention contains a main component represented by {Ba x Sr (1-x)} m Ta4O 12 and a first sub-component, where m satisfies 1.95 ≦ m ≦ 2.40, the first sub-component is silicon and manganese, when the content of the main component in the dielectric composition is 100 mole parts, The silicon content in the dielectric composition is 5.0 to 20.0 moles in terms of SiO2, and the manganese content in the dielectric composition is 1.0 to 4.5 moles in terms of MnO.

[0007] The dielectric composition according to the first aspect of the present invention exhibits high sintering density and high relative permittivity even when fired at relatively low temperatures (for example, 1200-1355°C). The reason for this is not entirely clear, but the following reasons are considered: When m is within the above range, and the dielectric composition contains predetermined amounts of silicon and manganese, it is thought that the sintering start temperature is lowered. As a result, it is thought that a high sintering density can be easily obtained even when fired at relatively low temperatures, and the relative permittivity is also improved.

[0008] Preferably, m is 2.10 ≤ m ≤ 2.40. This is thought to improve the wettability between the main component and the first minor component, and also lower the sintering start temperature. As a result, a higher sintering density can be obtained even at low temperatures, and the relative permittivity is also improved.

[0009] Preferably, the dielectric composition includes at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten as a second minor component. When the content of the main component in the dielectric composition is 100 moles, The dielectric composition contains at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten in an amount of 0.25 to 1.0 molar parts in terms of a predetermined oxide. The vanadium content is calculated on a V2O5 basis. The magnesium content is expressed in MgO equivalent. The zirconium content is expressed in terms of ZrO2 equivalent. The tungsten content is calculated on a WO3 basis.

[0010] The inclusion of a second minor component within the above range in the dielectric composition further lowers the sintering initiation temperature. This further improves the sintering density and the dielectric constant. In addition, the inclusion of a second minor component within the above range in the dielectric composition improves reduction resistance. As a result, the resistivity is further improved.

[0011] A dielectric composition according to a second aspect of the present invention is {Ba x Sr (1-x)} m Ta4O 12 It includes a principal component represented by and a first minor component, The above m is 1.95 ≤ m ≤ 2.40, The first minor component is silicon and manganese, When the content of the main component in the dielectric composition is 100 moles, The silicon content in the dielectric composition is 5.0 to 20.0 molar parts in terms of SiO2. The manganese content in the dielectric composition is 5.0 to 40.0 molar parts in terms of MnO.

[0012] The dielectric composition according to the second aspect of the present invention exhibits high sintering density and high relative permittivity even when fired at relatively lower temperatures (for example, 1150-1250°C). The reason for this is not entirely clear, but the following reasons are considered: When m is within the above range, and the dielectric composition contains predetermined amounts of silicon and manganese, it is thought that the sintering start temperature is lowered. As a result, it is thought that a high sintering density can be easily obtained even when fired at relatively lower temperatures, and the relative permittivity is also improved.

[0013] Preferably, m is 2.10 ≤ m ≤ 2.40. This is thought to improve the wettability between the main component and the first minor component, and also lower the sintering start temperature. As a result, a higher sintering density can be obtained even at low temperatures, and the relative permittivity is also improved.

[0014] Preferably, the dielectric composition includes, as a second minor component, at least one selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements. When the content of the main component in the dielectric composition is 100 moles, The dielectric composition contains at least one element selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements in an amount of 0.25 to 10.0 molars in terms of a predetermined oxide. The vanadium content is calculated on a V2O5 basis. The magnesium content is expressed in MgO equivalent. The zirconium content is expressed in terms of ZrO2 equivalent. The tungsten content is calculated on a WO3 basis. The content of rare earth elements represented by RE is calculated on a RE2O3 basis.

[0015] The inclusion of a second minor component within the above range in the dielectric composition further lowers the sintering initiation temperature. This further improves the sintering density and the dielectric constant. In addition, the inclusion of a second minor component within the above range in the dielectric composition improves reduction resistance. As a result, the resistivity is further improved.

[0016] The dielectric composition according to the present invention preferably contains substantially no niobium, alkali metals, and lead.

[0017] Examples of dielectric compositions exhibiting a high relative permittivity include (Sr,Ba)Nb2O6, which is mainly composed of niobium; (Na,K)NbO3, which contains alkali metals; and Pb(Zr,Ti)O3, which contains lead.

[0018] The dielectric composition according to the present invention is substantially free of niobium, making it less prone to oxygen vacancies. In other words, changes in valence are suppressed. Therefore, even when subjected to reduction firing, the valence does not change easily, the decrease in resistivity is suppressed, and it is believed that it can exhibit high resistivity over a wide temperature range. Furthermore, for the same reason, it is believed that it can exhibit low dielectric loss.

[0019] Furthermore, since the dielectric composition according to the present invention is substantially free of alkali metals, it is possible to prevent compositional shifts in the dielectric composition and contamination of the furnace due to the evaporation of alkali metals.

[0020] Furthermore, although the use of lead is restricted by regulations such as RoHS (Restriction of Hazardous Substances Directive), the dielectric composition according to the present invention is substantially lead-free.

[0021] Furthermore, the electronic component according to the present invention comprises the above-mentioned dielectric composition. [Brief explanation of the drawing]

[0022] [Figure 1] Figure 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of a thin-film capacitor according to one embodiment of the present invention. [Modes for carrying out the invention]

[0023] [First Embodiment] < Multilayer ceramic capacitor > Figure 1 shows a multilayer ceramic capacitor 1 as an example of an electronic component according to this embodiment. The multilayer ceramic capacitor 1 has an element body 10 in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. A pair of external electrodes 4 are formed at both ends of the element body 10, each of which is electrically connected to the internal electrode layers 3 that are alternately arranged inside the element body 10. There are no particular restrictions on the shape of the element body 10, but it is usually rectangular. There are also no particular restrictions on the dimensions of the element body 10, and it can be set to an appropriate size depending on the application.

[0024] < Dielectric layer > The dielectric layer 2 is composed of the dielectric composition according to this embodiment, which will be described later.

[0025] The thickness of each dielectric layer 2 (interlayer thickness) is not particularly limited and can be set according to the desired characteristics and applications. Typically, the interlayer thickness is preferably 30 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less.

[0026] < internal electrode layer > In this embodiment, the internal electrode layers 3 are stacked such that each end is alternately exposed on the surface of two opposing end faces of the element body 10.

[0027] The conductive material contained in the internal electrode layer 3 is not particularly limited. Examples of metals that can be used as conductive materials include palladium, platinum, silver-palladium alloys, nickel, nickel-based alloys, copper, copper-based alloys, etc. Note that nickel, nickel-based alloys, copper, or copper-based alloys may contain various trace components such as phosphorus and / or sulfur in amounts of approximately 0.1% by mass or less. Furthermore, the internal electrode layer 3 may be formed using commercially available electrode paste. The thickness of the internal electrode layer 3 can be appropriately determined depending on the application.

[0028] < external electrode > The conductive material contained in the external electrode 4 is not particularly limited. For example, known conductive materials such as nickel, copper, tin, silver, palladium, platinum, gold or alloys thereof, and conductive resins may be used. The thickness of the external electrode 4 may be determined appropriately depending on the application.

[0029] < Dielectric composition > The dielectric composition constituting the dielectric layer 2 according to this embodiment mainly comprises at least one of barium and strontium, and tantalum.

[0030] The main component of the dielectric composition according to this embodiment preferably contains strontium, and may contain both strontium and barium. twist preferable.

[0031] The main component of the dielectric composition according to this embodiment is {Ba x Sr (1-x)} m Ta4O 12 represented by

[0032] x is preferably 0.75 or less, more preferably less than 0.75, and even more preferably 0.1 to 0.50.

[0033] m is preferably 1.95 ≤ m ≤ 2.40, more preferably 2.10 ≤ m ≤ 2.40.

[0034] The crystal system of the crystal of the main component of the dielectric composition according to this embodiment is not particularly limited, but is preferably a tetragonal system or an orthorhombic system, and more preferably a tetragonal system.

[0035] In addition, in this embodiment, when the elements other than oxygen contained in the dielectric composition are 100 mol parts, the elements other than oxygen constituting the main component account for 50 to 99.5 mol parts.

[0036] Further, the dielectric composition according to this embodiment substantially does not contain niobium, alkali metal, and lead. "Substantially does not contain niobium, alkali metal, and lead" means that when the elements other than oxygen contained in the dielectric composition are 100 mol parts, the total of "niobium, alkali metal, and lead" is 10 mol parts or less, preferably 5 mol parts or less.

[0037] The dielectric composition according to this embodiment contains silicon and manganese as the first sub-components.

[0038] When the content of the main component in the dielectric composition is 100 mol parts, the content of silicon in the dielectric composition is Si O 2 exchange is 5.0 to 20.0 mol parts in terms of oxide conversion, preferably 10.0 to 17.5 mol parts. That is, the content of silicon is determined by oxide conversion when the valence of silicon is tetravalent.

[0039] When the content of the main component in the dielectric composition is 100 moles, the manganese content in the dielectric composition is 1.0 to 4.5 moles in terms of MnO, preferably 2.0 to 4.5 moles. In other words, the manganese content can be determined in terms of oxide when the valence of manganese is assumed to be 2.

[0040] The dielectric composition according to this embodiment preferably contains at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten as a second minor component.

[0041] Specifically, when the content of the main component in the dielectric composition is 100 mole parts, it is preferable that the dielectric composition contains at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten in a predetermined oxide equivalent of 0.25 to 10.0 mole parts.

[0042] The vanadium content is expressed on a V2O5 basis. In other words, the vanadium content is determined on an oxide basis, assuming a vanadium valence of 5.

[0043] The magnesium content is expressed in terms of MgO. That is, the magnesium content is determined in terms of oxides, assuming a magnesium valence of 2.

[0044] The zirconium content is expressed in terms of ZrO2. In other words, the zirconium content is determined in terms of oxide, assuming a zirconium valence of 4.

[0045] The tungsten content is expressed in WO3 equivalent terms. In other words, the tungsten content is determined in terms of oxide equivalents, assuming a valence of tungsten of 6.

[0046] In addition to the main component, first minor component, and second minor component described above, the dielectric composition according to this embodiment may also contain aluminum, calcium, chromium, rare earth elements, and the like.

[0047] < Manufacturing method for multilayer ceramic capacitors > Next, an example of a manufacturing method for the multilayer ceramic capacitor 1 shown in Figure 1 will be described.

[0048] In this embodiment, the main component powder and the first and second minor component powders constituting the dielectric composition are prepared. The method for producing the main component powder is not particularly limited, but it can be produced by a solid-phase reaction method such as calcination. The raw materials for each element constituting the main component powder and the first and second minor component powders are not particularly limited, and oxides of each element can be used. In addition, various compounds that can be used to obtain oxides of each element by calcination can be used.

[0049] After weighing the main component powder and the first and second minor component powders in predetermined proportions, wet mixing is performed for a predetermined time using a ball mill or the like. After drying the mixed powder, heat treatment is performed in the air at a temperature of 700 to 1300°C to obtain calcined powder of the main component and the first and second minor components. Alternatively, the calcined powder may be ground for a predetermined time using a ball mill or the like.

[0050] Next, a paste for producing green chips is prepared. The obtained calcined powder and solvent are kneaded together to form a paint-like paste for the dielectric layer. Known binders and solvents may be used.

[0051] The dielectric layer paste may contain additives such as plasticizers and dispersants, as needed.

[0052] The paste for the internal electrode layer is obtained by kneading the conductive material raw materials, a binder, and a solvent as described above. Known binders and solvents may be used. The paste for the internal electrode layer may also contain additives such as co-materials or plasticizers, as needed.

[0053] The paste for the external electrode can be prepared in the same manner as the paste for the internal electrode layer.

[0054] Using the obtained pastes, green sheets and internal electrode patterns are formed, and these are stacked to obtain green chips.

[0055] The obtained green chips are subjected to a binder removal treatment as needed. The binder removal treatment conditions include, for example, a holding temperature of preferably 200 to 350°C.

[0056] After the binder removal process, the green chips are fired to obtain the element body 10. In this embodiment, the atmosphere during firing is not particularly limited and may be in air or in a reducing atmosphere. In this embodiment, the holding temperature during firing is, for example, 1200 to 1355°C.

[0057] After firing, the obtained element body 10 is subjected to re-oxidation treatment (annealing) as needed. Preferably, the annealing conditions are such that the oxygen partial pressure during annealing is higher than the oxygen partial pressure during firing, and the holding temperature is 1150°C or lower.

[0058] The dielectric composition constituting the dielectric layer 2 of the element body 10 obtained as described above is the dielectric composition described above. The element body 10 is subjected to end face polishing, and an external electrode paste is applied and baked to form the external electrode 4. Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.

[0059] In this way, the multilayer ceramic capacitor 1 according to this embodiment is manufactured.

[0060] The dielectric composition according to this embodiment has {Ba} as its main component. x Sr (1-x)} m Ta4O 12 By including a certain component, where m is within a predetermined range, and containing a predetermined amount of silicon and manganese as the first minor component, a dielectric composition with high sintering density and high relative permittivity can be obtained even when the dielectric composition is fired and sintered at a relatively low temperature (for example, 1200 to 1355°C).

[0061] The reason is not entirely clear, but the following reasons are possible: When m is within the above range, and the dielectric composition contains predetermined amounts of silicon and manganese, it is thought that the sintering start temperature is lowered. As a result, it is thought that a high sintering density can be easily obtained even when fired at a relatively low temperature, and the relative permittivity is also improved.

[0062] Furthermore, according to this embodiment, a dielectric composition that is substantially free of niobium, alkali metals, and lead, and exhibits high density, high dielectric constant, low dielectric loss, and high resistivity can be obtained.

[0063] The dielectric composition according to this embodiment, which contains tantalum and substantially no niobium, tends to exhibit a higher dielectric constant, lower dielectric loss, and higher resistivity compared to conventional dielectric compositions that do not contain tantalum and do contain niobium. This is likely because tantalum oxide (Ta2O5) is less prone to generating oxygen vacancies than niobium oxide (Nb2O5).

[0064] Dielectric properties are characteristics that assume the material is an insulator. Therefore, dielectric compositions are required to have high resistance so that they do not become semiconducting or conductive. As mentioned above, tantalum oxide (Ta2O5) is less prone to oxygen vacancies than niobium oxide (Nb2O5). In other words, the change in valence state is controlled. For this reason, the decrease in resistivity is suppressed, and it is thought that it can exhibit high resistivity over a high temperature range. Also, for the same reason, it is thought that it can exhibit low dielectric loss.

[0065] [Second Embodiment] < Thin-film capacitor > A schematic diagram of the thin-film capacitor 11 according to this embodiment is shown in Figure 2. The thin-film capacitor 11 shown in Figure 2 is formed on a substrate 111 in the order of a lower electrode 112 and a dielectric thin film 113, and an upper electrode 114 is provided on the surface of the dielectric thin film 113.

[0066] There are no particular restrictions on the material of the substrate 111, but using a silicon single crystal substrate as the substrate 111 offers advantages in terms of availability and cost-effectiveness. If flexibility is a priority, nickel foil or copper foil can also be used as the substrate.

[0067] There are no particular restrictions on the material of the lower electrode 112 and the upper electrode 114; any material that functions as an electrode is acceptable. Examples include platinum, silver, and nickel. The thickness of the lower electrode 112 is not particularly limited, for example, 0.01 to 10 μm. The thickness of the upper electrode 114 is also not particularly limited, for example, 0.01 to 10 μm.

[0068] The composition of the dielectric composition constituting the dielectric thin film 113 according to this embodiment and the crystal system of the main component are the same as in the first embodiment.

[0069] There are no particular restrictions on the thickness of the dielectric thin film 113, but it is preferably 10 nm to 1 μm.

[0070] < Manufacturing method for thin-film capacitors > Next, the manufacturing method for the thin-film capacitor 11 will be described.

[0071] There are no particular restrictions on the method for depositing the thin film that will ultimately become the dielectric thin film 113. Examples include vacuum deposition, sputtering, PLD (pulsed laser deposition), MO-CVD (metal-organic chemical vapor deposition), MOD (metal-organic decomposition), sol-gel method, and CSD (chemical solution deposition).

[0072] Furthermore, while the raw materials used during film formation may contain minute impurities or by-components, this is not a problem as long as the amount does not significantly impair the performance of the thin film. Similarly, the dielectric thin film 113 according to this embodiment may also contain minute impurities or by-components in an amount that does not significantly impair its performance.

[0073] In this embodiment, a film deposition method using the PLD method will be described.

[0074] First, a silicon single crystal substrate is prepared as substrate 111. Next, SiO2 and TiO2 are placed on the silicon single crystal substrate. x A film is deposited in the order of platinum, and then a lower electrode 112 made of platinum is formed. There are no particular restrictions on the method of forming the lower electrode 112. For example, sputtering or CVD can be used.

[0075] Next, a dielectric thin film 113 is deposited on the lower electrode 112 using the PLD method. Alternatively, a metal mask may be used to create a region where the thin film is not deposited in order to expose a portion of the lower electrode 112.

[0076] In the PLD method, first, a target containing the constituent elements of the target dielectric thin film 113 is placed in the deposition chamber. Next, a pulsed laser is irradiated onto the surface of the target. The high energy of the pulsed laser instantly vaporizes the surface of the target. Then, the vapor is deposited onto a substrate placed opposite the target to form the dielectric thin film 113.

[0077] There are no particular restrictions on the type of target; in addition to metal oxide sintered bodies containing the constituent elements of the dielectric thin film 113 to be fabricated, alloys and the like can be used. Furthermore, while it is preferable that each element is evenly distributed in the target, variations in distribution are acceptable as long as they do not affect the quality of the resulting dielectric thin film 113.

[0078] The target does not necessarily have to be just one; it is also possible to prepare multiple targets containing some of the constituent elements of the dielectric thin film 113 and use them for film deposition. There are no restrictions on the shape of the target; it should be a shape suitable for the film deposition equipment being used.

[0079] Furthermore, in the PLD method, it is preferable to heat the substrate 111 with an infrared laser during film deposition in order to crystallize the dielectric thin film 113 to be deposited. The heating temperature of the substrate 111 varies depending on the constituent elements and composition of the dielectric thin film 113 and the substrate 111, but for example, the film deposition is carried out by heating to 600 to 800°C. By setting the temperature of the substrate 111 to an appropriate temperature, the dielectric thin film 113 can be easily crystallized and cracks that occur during cooling can be prevented.

[0080] Finally, the thin-film capacitor 11 can be manufactured by forming an upper electrode 114 on the dielectric thin film 113. There are no particular restrictions on the material of the upper electrode 114; silver, gold, copper, etc., can be used. There are also no particular restrictions on the method of forming the upper electrode 114. For example, it can be formed by vapor deposition or sputtering.

[0081] [Third Embodiment] The third embodiment will be described below, but unless otherwise specified, it is the same as the first embodiment.

[0082] In this embodiment, when the content of the main component in the dielectric composition is 100 moles, the manganese content in the dielectric composition is 5.0 to 40.0 moles in terms of MnO, preferably 7.5 to 30.0 moles.

[0083] The dielectric composition according to this embodiment preferably contains at least one element selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements as a second minor component.

[0084] Specifically, when the content of the main component in the dielectric composition is 100 mole parts, it is preferable that the dielectric composition contains at least one element selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements in a predetermined oxide equivalent of 0.25 to 10.0 mole parts.

[0085] Rare earth elements are represented by "RE". The content of rare earth elements (RE) is expressed in terms of RE2O3. In other words, the content of rare earth elements is determined in terms of oxides, assuming the valence of the rare earth elements is 3.

[0086] Examples of rare earth elements include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and can be used individually or in combination of two or more.

[0087] In addition to the main component, first minor component, and second minor component described above, the dielectric composition according to this embodiment may also contain aluminum, calcium, chromium, titanium, hafnium, molybdenum, and the like.

[0088] In this embodiment, the holding temperature during firing is, for example, 1150 to 1250°C.

[0089] The dielectric composition according to this embodiment has {Ba} as its main component. x Sr (1-x)} m Ta4O 12 By including a predetermined amount of silicon and manganese as the first minor component, and with m being within a predetermined range, a dielectric composition with high sintering density and high relative permittivity can be obtained even when the dielectric composition is fired and sintered at a relatively lower temperature (for example, 1150-1250°C).

[0090] The reason is not entirely clear, but the following reasons are possible: When m is within the above range, and the dielectric composition contains a predetermined amount of silicon and manganese, it is thought that the sintering start temperature is lowered. As a result, it is thought that a high sintering density can be easily obtained even when fired at a relatively lower temperature, and the relative permittivity is also improved.

[0091] Although embodiments of the present invention have been described above, the present invention is not limited in any way to these embodiments, and can be implemented in various different ways without departing from the spirit of the invention.

[0092] In the above-described embodiment, the case in which the electronic component according to the present invention is a multilayer ceramic capacitor was explained, but the electronic component according to the present invention is not limited to a multilayer ceramic capacitor, and any electronic component having the dielectric composition described above may be used.

[0093] For example, a single-layer ceramic capacitor may be provided, in which a pair of electrodes are formed on a single-layer dielectric substrate made of the dielectric composition described above.

[0094] Furthermore, the electronic component according to the present invention may be a capacitor, filter, diplexer, resonator, oscillator, antenna, or the like. [Examples]

[0095] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples.

[0096] As starting materials for the main components of the dielectric composition, powders of barium carbonate (BaCO3), strontium carbonate (SrCO3), and tantalum oxide (Ta2O5) were prepared. x Sr (1-x)} m Ta4O 12 The starting materials for the main components were weighed so that x in the composition of the main components represented by is 0.5 in Tables 1, 2, 4, and 5, and as described in Table 3 or Table 6 in Table 3 or Table 6, and so that m is as described in Tables 1 to 6.

[0097] Furthermore, as starting materials for the first and second minor components of the dielectric composition, each raw material powder was prepared and weighed so that the content of the first and second minor components after calcination would be as shown in Tables 1 to 6. Note that "content of the first and second minor components" refers to "the content of the first and second minor components in the dielectric composition in terms of a predetermined oxide, when the content of the main component in the dielectric composition is assumed to be 100 moles."

[0098] Next, each weighed powder was wet-mixed using deionized water as a dispersion medium in a ball mill, and the mixture was dried to obtain a mixed raw material powder. Subsequently, the obtained mixed raw material powder was heat-treated in air at a holding temperature of 900°C for a holding time of 2 hours to obtain calcined powder.

[0099] The obtained calcined powder was wet-milled using a ball mill with ion-exchanged water as a dispersion medium, dried, and obtained dielectric raw material.

[0100] To 100 parts by mass of the obtained dielectric material, 10 parts by mass of an aqueous solution containing 6 parts by mass of polyvinyl alcohol resin as a binder was added and granulated to obtain granulated powder.

[0101] The resulting granulated powder is placed into a φ12mm mold at a rate of 0.6 ton / cm³. 2 Pre-press forming is performed with a pressure of 1.2 tons / cm², and then further, 1.2 tons / cm² is applied. 2 A disc-shaped green molded body was obtained by press molding under this pressure.

[0102] Next, the obtained green molded body was subjected to binder removal, firing, and annealing under the following conditions to obtain the element body.

[0103] The binder removal treatment conditions were: holding temperature: 400°C, holding time: 2 hours, atmosphere: air.

[0104] For each sample in Tables 1 to 3, the holding temperature during firing was 1350°C. For each sample in Tables 4 to 6, the holding temperature during firing was 1250°C. Other firing conditions were: temperature holding time: 2 hours, atmosphere: humidified N2+H2 mixed gas (oxygen partial pressure 10%). -12 The pressure was set to MPa. A wetter was used to humidify the atmospheric gas during firing.

[0105] The annealing conditions were: holding temperature: 1050°C, holding time: 2 hours, ambient gas: humidified N2 gas (oxygen partial pressure: 10°C). -7The pressure was set to MPa. A wetter was used to humidify the atmospheric gas during annealing.

[0106] The sintering density, relative permittivity, and resistivity of the obtained sintered body (dielectric composition) were investigated by the following method. For the measurement of relative permittivity and resistivity, an In-Ga electrode was applied to the above-mentioned dielectric composition (sintered body) to obtain a disc-shaped ceramic capacitor sample (capacitor sample).

[0107] < Sintering density > The sintering density of the dielectric composition was measured as follows. First, the volume V of the dielectric composition was calculated. Next, the mass M of the disc-shaped dielectric composition was measured, and the sintering density of the dielectric composition was obtained by calculating M / V. The results are shown in Tables 1 to 6.

[0108] < Relative permittivity > Capacitance C was measured on a capacitor sample at room temperature (20°C) using a digital LCR meter (YHP 4284A) with a frequency of 1 kHz and an input signal level (measurement voltage) of 1 Vrms. The relative permittivity was then calculated based on the thickness of the dielectric composition, the effective electrode area, and the capacitance C obtained from the measurement. The results are shown in Tables 1 to 6.

[0109] < specific resistance > The insulation resistance of the capacitor sample was measured at a reference temperature (25°C) using a digital resistance meter (ADVANTEST R8340). The resistivity was calculated from the obtained insulation resistance, effective electrode area, and dielectric composition thickness. The results are shown in Tables 1 to 6.

[0110] [Table 1]

[0111] [Table 2]

[0112] [Table 3]

[0113] [Table 4]

[0114] [Table 5]

[0115] [Table 6]

[0116] From Tables 1 to 3, {Ba x Sr (1-x)} m Ta4O 12 When m is 1.95 ≤ m ≤ 2.40, the silicon content is 5.0 to 20.0 molar parts in terms of SiO2, and the manganese content is 1.0 to 4.5 molar parts in terms of MnO (sample numbers 5 to 11, 16 to 21, 25 to 30, 32 to 47, 48 to 51), the sintered density is 6.50 g / cm³. 3 The above conditions are met, the relative permittivity is 70 or higher, and the resistivity is 1.0 × 10⁻⁶. 11 This has been confirmed.

[0117] From Tables 1 to 3, {Ba x Sr (1-x)} m Ta4O 12 When m is 2.10 ≤ m ≤ 2.40, silicon content is 5.0 to 20.0 molar parts in terms of SiO2, and manganese content is 1.0 to 4.5 molar parts in terms of MnO (sample numbers 8 to 11, 35 to 47, 48 to 51), the sintered density is 7.00 g / cm³. 3 The above conditions are met, the relative permittivity is 100 or more, and the resistivity is 1.0 × 10⁻⁶. 11 This has been confirmed.

[0118] From Tables 1 to 3, {Bax Sr (1-x)} m Ta4O 12 When m is 2.10 ≤ m ≤ 2.40, the silicon content is 5.0 to 20.0 molar parts in terms of SiO2, the manganese content is 1.0 to 4.5 molar parts in terms of MnO, and the content of at least one of vanadium, magnesium, zirconium, and tungsten is 0.25 to 1.0 molar parts in terms of a given oxide (sample numbers 39 to 47), the sintered density is 7.00 g / cm³. 3 The above conditions are met, the relative permittivity is 120 or greater, and the resistivity is 1.0 × 10⁻⁶. 12 This has been confirmed.

[0119] From Tables 4 to 6, {Ba x Sr (1-x)} m Ta4O 12 When m is 1.95 ≤ m ≤ 2.40, the silicon content is 5.0 to 20.0 molar parts in terms of SiO2, and the manganese content is 5.0 to 40.0 molar parts in terms of MnO (sample numbers 15 to 111, 116 to 121, 125 to 132, 134 to 158, 161 to 164), the sintered density is 6.50 g / cm³. 3 The above conditions are met, the relative permittivity is 70 or higher, and the resistivity is 1.0 × 10⁻⁶. 11 This has been confirmed.

[0120] From Tables 4 to 6, {Ba x Sr (1-x)} m Ta4O 12 When m is 2.10 ≤ m ≤ 2.40, silicon content is 5.0 to 20.0 molar parts in terms of SiO2, and manganese content is 5.0 to 40.0 molar parts in terms of MnO (sample numbers 18 to 111, 137 to 158, 161 to 164), the sintered density is 7.00 g / cm³. 3 The above conditions are met, the relative permittivity is 100 or more, and the resistivity is 1.0 × 10⁻⁶. 11 This has been confirmed.

[0121] From Tables 4 to 6, {Ba x Sr (1-x)}m Ta4O 12 When m is 2.10 ≤ m ≤ 2.40, the silicon content is 5.0 to 20.0 molar parts in terms of SiO2, the manganese content is 5.0 to 40.0 molar parts in terms of MnO, and the content of at least one of vanadium, magnesium, zirconium, tungsten, and rare earth elements is 0.25 to 10.0 molar parts in terms of a given oxide (sample numbers 141 to 158), the sintered density is 7.00 g / cm³. 3 The above conditions are met, the relative permittivity is 120 or greater, and the resistivity is 1.0 × 10⁻⁶. 12 This has been confirmed. [Explanation of Symbols]

[0122] 1… Multilayer ceramic capacitor 10… Element body 2… Dielectric layer 3… Internal electrode layer 4… External electrode 11… Thin-film capacitor 111… Circuit board 112… Lower electrode 113… Polycrystalline dielectric thin film 114...Top electrode

Claims

1. {Ba x Sr (1-x) } m Ta 4 O 12 A dielectric composition comprising a main component represented by and a first minor component, wherein x is 0.75 or less and m is 1.95 ≤ m ≤ 2.40, The first minor component is silicon and manganese, When the content of the main component in the dielectric composition is 100 mole parts, The silicon content in the dielectric composition is SiO 2 This is equivalent to 5.0 to 20.0 mole parts. The dielectric composition wherein the manganese content in the dielectric composition is 1.0 to 4.5 molar parts in terms of MnO.

2. The dielectric composition according to claim 1, wherein m is 2.10 ≤ m ≤ 2.

40.

3. The dielectric composition includes, as a second minor component, at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten. When the content of the main component in the dielectric composition is 100 mole parts, The dielectric composition contains at least one selected from the group consisting of vanadium, magnesium, zirconium, and tungsten in an amount of 0.25 to 1.0 molar parts in terms of a predetermined oxide. The vanadium content is V 2 O 5 This is a conversion. The magnesium content is expressed in MgO equivalent. The zirconium content is in terms of ZrO 2 equivalent, The tungsten content is WO 3 The dielectric composition according to claim 1, which is a conversion.

4. {Ba x Sr (1-x) } m Ta 4 O 12 A dielectric composition comprising a main component represented by and a first minor component, wherein x is 0.75 or less and m is 1.95 ≤ m ≤ 2.40, The first minor component is silicon and manganese, When the content of the main component in the dielectric composition is 100 mole parts, The silicon content in the dielectric composition is SiO 2 This is equivalent to 5.0 to 20.0 mole parts. The dielectric composition wherein the manganese content in the dielectric composition is 5.0 to 40.0 molar parts in terms of MnO.

5. The dielectric composition according to claim 4, wherein m is 2.10 ≤ m ≤ 2.

40.

6. The dielectric composition includes, as a second minor component, at least one selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements. When the content of the main component in the dielectric composition is 100 mole parts, The dielectric composition contains at least one element selected from the group consisting of vanadium, magnesium, zirconium, tungsten, and rare earth elements in an amount of 0.25 to 10.0 molars, calculated on an oxide basis. The vanadium content is V 2 O 5 This is a conversion. The magnesium content is expressed in MgO equivalent. The zirconium content is ZrO 2 This is a conversion. The tungsten content is WO 3 This is a conversion. The content of rare earth elements represented by RE is RE 2 O 3 The dielectric composition according to claim 4, which is a conversion.

7. An electronic component comprising the dielectric composition according to any one of claims 1 to 6.

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