DIELECTRIC CERAMIC COMPOSITION AND LAMINATED ELECTRONIC CERAMIC COMPONENT

Abstract

A dielectric ceramic composition comprises first crystal grains having a perovskite structure represented by the general formula ABO3, each first crystal grain having a core portion and a shell portion, the shell portion covering the core portion and containing a rare earth element and manganese; and second crystal grains whose main component is a barium titanate complex oxide in which an element ratio of barium to titanium is 0.70 or less.

Description

Technical area

[0001] The present invention relates to a dielectric ceramic composition and a multilayer ceramic electronic component. State of the art

[0002] Multilayer ceramic electronic components, such as multilayer ceramic capacitors (MLCC), are used in high-frequency communication systems such as mobile phones. Prior art documentsPatent documents Patent Document 1: Japanese Laid-Open Patent Application Publication No. 2012-131669 Patent Document 2: Japanese Laid-Open Patent Application Publication No. 2016-153359 SUMMARY OF THE INVENTION Problems to be solved by the invention

[0003] In recent years, the use of multilayer ceramic electronic components has expanded, even in electronic circuits that affect human life, such as in-vehicle electronic control devices. This requires high reliability and, in view of delivery volumes, higher mass productivity.

[0004] As the dielectric ceramic composition used for the dielectric layer of multilayer ceramic electronic components, a sintered body with a core-shell structure was used, in which barium titanate was used as the core part and a shell part containing various additives as a solid solution was used to surround the core part. By using this structure, the occurrence of a large capacitance in the shell part, which would otherwise occur near the Curie temperature, where barium titanate changes from the ferroelectric phase to the paraelectric phase, which exists at about 125°C, can be shifted to a lower temperature range due to the effects of the various additives. This allows designs to be produced that exhibit increased capacitances in the practical temperature range near room temperature.

[0005] The core-shell structure is believed to be formed by dissolving various additives in barium titanate. The core-shell structure is believed to be formed by the reaction of various additives added to barium titanate particles, the main component, in the firing temperature range of, for example, 1000°C to 1400°C. Generally, as the firing temperature increases, various additives dissolve into a solid solution, and the shell portion becomes thicker. Therefore, to maintain the capacitance of the multilayer ceramic electronic component within the desired range, it is necessary to precisely control or adjust the firing temperature.

[0006] As an application example of barium titanate without a core-shell structure, a piezoelectric ceramic was disclosed which, as a barium titanate complex oxide, contains at least one of Ba4Ti 12 O 27 or Ba6Ti 17 O 40and which contains 0.04 to 0.20 mass% or less of manganese based on barium titanate (see, for example, Patent Document 1).

[0007] Furthermore, a piezoelectric ceramic was disclosed which comprises a metal oxide formed by (Ba 1-x Ca x ) a (Ti 1-y Zr y )O3 (where 0.09 ≦ x ≦ 0.30, 0.025 ≦ y ≦ 0.085, 0.986 ≦ a ≦ 1.020) and contains 0.04 parts by weight or more and 0.36 parts by weight or less of manganese based on 100 parts by weight of the metal oxide, and which contains, as the barium titanate complex oxide, at least one metal oxide selected from BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O 13 , BaTi7O 14 , BaTi8O 16 , Ba2Ti5O 12 , Ba2Ti6O 13 , Ba2Ti9O 20 , Ba4Ti 11 O 26 , Ba4Ti 13 O 30 , CaTi2O4, CaTi2O5, CaTi4O9, Ca2Ti5O 12 , CaZr4O9, Ca2Zr7O 16 , Ca6Zr 19 O 44 , CaZrTi2O7 and Ca2Zr5Ti2O 16, contains (see, for example, Patent Document 2).

[0008] When attempting to apply the piezoelectric ceramics disclosed in Patent Document 1 and Patent Document 2 to a dielectric ceramic composition used in the dielectric layer of a multilayer ceramic electronic component, as described in Patent Documents 1 and 2, it was found that the maximum grain size of crystal grains reached 2 μm or more. It was found that, for multilayer ceramic electronic components, when the dielectric layer was 10 μm or less, the number of grain boundaries decreased, and a problem arose in that the insulating properties were significantly deteriorated. Furthermore, the temperature rise rate during firing of the piezoelectric ceramic was at most 10 °C / min, and therefore, the high mass productivity required for multilayer ceramic electronic components was not achieved.

[0009] In recent years, the applications of dielectric ceramic compositions and multilayer ceramic electronic components have expanded, and higher mass productivity is required. To achieve high mass productivity, firing times are required in a shorter time. Therefore, it is necessary to reduce capacitance changes due to firing temperatures and to reduce capacitance fluctuations due to temperature.

[0010] The present invention has been made in consideration of the above-mentioned problems of the prior art, and an object of the present invention is to provide a dielectric ceramic composition and a multilayer ceramic electronic component which can prevent the changes in capacitance due to the firing temperature. Means to solve the problems

[0011] A dielectric ceramic composition according to the present invention comprises first crystal grains having a perovskite structure represented by the general formula ABO3, the first crystal grains each having a core portion and a shell portion covering the core portion and containing a rare earth element and manganese, and second crystal grains whose main component is a barium titanate complex oxide in which an element ratio of barium to titanium is 0.70 or less.

[0012] In the above dielectric ceramic composition, the rare earth element may be at least one selected from gadolinium, europium, terbium, dysprosium, holmium, erbium and ytterbium.

[0013] In the above dielectric ceramic composition, an element ratio of barium to titanium may be 0.926 or more and 0.995 or less, an element ratio of the rare earth element to titanium may be 0.005 or more and 0.05 or less, and an element ratio of manganese to titanium may be 0.002 or more and 0.05 or less.

[0014] The above dielectric ceramic composition may further contain silicon having an element ratio of 0.002 or more and 0.05 or less with respect to titanium and magnesium having an element ratio of 0.00 or more to 0.05 or less with respect to titanium.

[0015] In the above dielectric ceramic composition, the element concentrations of the rare earth element and manganese in the shell portion may be higher than the element concentrations of the rare earth element and manganese in the core portion.

[0016] In the above dielectric ceramic composition, the first crystal grains may have a maximum grain size of 2 µm or less.

[0017] In the above dielectric ceramic composition, the second crystal grain may have an element ratio of barium to titanium of 0.16 or more.

[0018] In the above dielectric ceramic composition, the second crystal grain may be at least one selected from BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O 13 , Ba4Ti 11 O 26 , Ba4Ti 12 O 27 , Ba4Ti 13 O 30 or Ba6Ti 17 O 40 , be.

[0019] In the above dielectric ceramic composition, the second crystal grain may contain manganese, and an element ratio of manganese to titanium in the second crystal grain may be 0.02 or more and 0.10 or less.

[0020] In the above dielectric ceramic composition, the second crystal grain may contain manganese, and an element ratio of manganese to titanium in the second crystal grain may be 0.02 or more and 0.05 or less.

[0021] Another dielectric ceramic composition according to the present invention comprises first crystal grains having a perovskite structure represented by the general formula ABO3, the first crystal grains each having a core portion and a shell portion covering the core portion and containing a rare earth element and manganese; and second crystal grains which are a barium titanate complex oxide represented by Ba4Ti 11 O 26 and containing manganese, wherein an element ratio of barium to titanium is 0.02 or more and 0.10 or less.

[0022] In the above dielectric ceramic composition, the rare earth element may be at least one selected from gadolinium, europium, terbium, dysprosium, holmium, erbium and ytterbium.

[0023] In the above dielectric ceramic composition, an element ratio of barium to titanium may be 0.926 or more and 0.995 or less, an element ratio of the rare earth element to titanium may be 0.005 or more and 0.05 or less, and an element ratio of manganese to titanium may be 0.002 or more and 0.05 or less.

[0024] The dielectric ceramic composition may further contain silicon having an element ratio of 0.002 or more and 0.05 or less with respect to titanium and magnesium having an element ratio of 0.00 or more and 0.05 or less with respect to titanium.

[0025] In the above dielectric ceramic composition, element concentrations of the rare earth element and manganese in the shell portion may be higher than element concentrations of the rare earth element and manganese in the core portion.

[0026] In the above dielectric ceramic composition, the first crystal grains may have a maximum grain size of 2 µm or less.

[0027] In the above dielectric ceramic composition, the element ratio of manganese to titanium in the second crystal grains may be 0.02 or more and 0.05 or less.

[0028] A multilayer ceramic electronic component according to the present invention utilizes any of the above-mentioned dielectric ceramic compositions.

[0029] The above-described multilayer ceramic electronic component comprises a plurality of internal electrodes facing each other; dielectric layers provided between the plurality of internal electrodes and containing the dielectric ceramic composition according to claim 1; and external electrodes each electrically connected to the internal electrodes. Effects of the invention

[0030] According to the present invention, a dielectric ceramic composition and a multilayer ceramic electronic component can be provided which can prevent changes in capacitance due to firing temperature. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a dielectric ceramic composition according to a first embodiment. Fig. Figure 2 is a diagram showing a unit cell. Fig.Figure 3 is a diagram showing a method for confirming a core-shell structure. Fig. 4 is a perspective partial cross-sectional view of a multilayer ceramic capacitor. Fig. 5 is a sectional view taken along the line AA in the Fig. 4. Fig. 6 is a sectional view along the line BB in the Fig. 4. Fig. 7 is a diagram showing a flow of a method for manufacturing a multilayer ceramic capacitor. Fig. 8(a) and Fig. 8(b) are diagrams showing a process of forming an inner electrode. Fig. 9 is a figure showing a pressing process. Fig. 10 is a figure showing side margin parts. DETAILED DESCRIPTION OF EMBODIMENTS

[0031] Embodiments will be described below with reference to the drawings. (First embodiment)

[0032] The dielectric ceramic composition according to a first embodiment is a polycrystalline ceramic body containing crystal grains having a perovskite structure represented by the general formula ABO3 as described in Fig. 1. Of the polycrystalline ceramic bodies, at least one of them is a first crystal grain 41 having a core-shell structure, and at least one of them is a second crystal grain 42 in which the element ratio of barium to titanium is 0.70 or less.

[0033] The first crystal grain 41 includes a substantially spherical core portion 411 and a shell portion 412 surrounding and covering the core portion 411. The core portion 411 is a crystalline portion in which the additive compound is not dissolved in a solid solution or the amount of the additive compound in solid solution is small. The shell portion 412 is a crystalline portion in which the additive compound is dissolved in a solid solution and has a higher concentration of the additive compound than the concentration of the additive compound in the core portion 411. In this embodiment, the shell portion 412 contains rare earth elements and manganese. The rare earth element is not specifically limited but may be at least one selected from gadolinium, europium, terbium, dysprosium, holmium, erbium, and ytterbium.Furthermore, the element concentrations of rare earth elements and manganese in the cladding portion 412 are higher than those in the core portion 411.

[0034] By including the first crystal grains 41 and the second crystal grains 42, the dielectric ceramic composition according to the present embodiment can prevent changes in capacitance due to the firing temperature.

[0035] For example, when observing a cross section of the dielectric ceramic composition in a field of view, in which a total of 400 or more first crystal grains 41 and second crystal grains 42 are observed, the area ratio of the first crystal grains 41 is 50% or more and 99.95% or less, and the area ratio of the second crystal grains 42 is 0.05% or more and 50% or less.

[0036] It should be noted that, in addition to the first crystal grains 41 and the second crystal grains 42, the dielectric ceramic composition may also include third crystal grains 43 having a different composition or crystal structure, and voids 44, etc. For example, when a cross section of the dielectric ceramic composition is observed in a field of view where a total of 400 or more first crystal grains 41, second crystal grains 42, and third crystal grains 43 are observed, the area ratio of the third crystal grains 43 is 0.05% or more and 20% or less.

[0037] Crystal grains with a perovskite structure, which are the main components of the first crystal grains 41, have a unit cell as shown in the Fig.2. This unit cell has the A position at the corner of the lattice, the O position at the face center of the lattice, and the B position within an octahedron with the O position as the corner. In the perovskite structure, alkaline earth metals that can form divalent cations, such as barium (Ba), strontium (Sr), and calcium (Ca), are located at the A position, and hafnium (Hf) and zirconium (Zr) are located at the B position, along with titanium (Ti) and other metal atoms that can form tetravalent cations.

[0038] The perovskite structure also allows for a composition formula that deviates from the stoichiometric composition. This means that the ratio of the element at position A to the element at position B does not necessarily have to be 1:1, and defects can be created within a range where the perovskite structure can be maintained. Furthermore, defects can also be created with respect to oxygen. For example, if the composition formula A α BO 3-β compositions in the ranges of 0.98 ≦ α ≦ 1.01 and 0 ≦ β ≦ 0.20 are permitted.

[0039] For example, due to the generation of oxygen defects, the resistivity decreases and ionic conductivity occurs, which reduces the electrical lifetime when used as a multilayer ceramic capacitor and increases the dielectric loss, making it impractical. Therefore, at least one of the first transition elements: scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn) can be added to the first crystal grains 41 having a perovskite structure. This can improve the resistivity, extend the electrical lifetime, and reduce the dielectric loss of the capacitance.

[0040] Furthermore, the first crystal grains (which may be referred to as particles) 41 may comprise at least one of the second transition elements, such as yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), and silver (Ag). This can improve the resistivity, extend the electrical lifetime, and reduce the dielectric loss of capacitance.

[0041] Furthermore, the first crystal grains 41 may comprise at least one of the third transition elements, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au). This can improve the resistivity, extend the electrical lifetime, and reduce the dielectric loss of capacitance.

[0042] For example, it is preferable to add titanium to the dielectric ceramic composition in an amount of 0.5 mol or more and 8.0 mol or less in terms of titanium oxide (TiO2) for 100 mol of barium titanate so that the Ba / Ti element ratio x, which is the element ratio of barium to the titanium content, satisfies 0.926 ≦ x ≦ 0.995. In this case, the solid solution reaction to the barium titanate crystal particles is relatively suppressed compared to the case where no additive containing titanium is added. Due to this, when applied to multilayer ceramic capacitors requiring high mass production, it becomes possible to achieve firing in a shorter time while reducing the rate of change in capacitance due to changes in firing temperature, thereby achieving high mass productivity.

[0043] It is more preferable to add titanium to the dielectric ceramic composition in an amount of 2.0 mol or more and 6.4 mol or less in terms of titanium oxide (TiO2) for 100 mol of barium titanate such that the Ba / Ti element ratio x satisfies 0.940 ≦ x ≦ 0.980. This allows a sufficient amount of second crystal grains 42 to be generated in the dielectric ceramic composition, and it becomes possible to better reduce the range of change in capacitance due to a change in firing temperature.

[0044] Preferred examples of the above-mentioned titanium-containing additives include titanium oxide, titanium hydroxide (Ti(OH)4), titanium chloride (TiCl4), titanium carbide (TiC) and titanium sulfide (TiS2), etc., can also be used.

[0045] Further, it is preferable to add gadolinium to the dielectric ceramic composition in an amount of 0.25 mol or more and 2.5 mol or less based on gadolinium oxide (Gd2O3) for 100 mol of barium titanate such that the Gd / Ti element ratio y, which is the element ratio of the rare earth element such as gadolinium to the titanium content, is, for example, 0.005 ≦ y ≦ 0.05.

[0046] In addition to adding gadolinium oxide, it is preferable to add manganese in an amount of 0.2 mol or more and 5.0 mol or less in terms of manganese oxide (MnO) for 100 mol of barium titanate so that the Mn / Ti element ratio z, which is the manganese element ratio to the titanium content, satisfies 0.002 ≦ z ≦ 0.05.

[0047] For example, when 0.926 ≦ x ≦ 0.995, 0.005 ≦ y ≦ 0.05, and 0.002 ≦ z ≦ 0.05, the added gadolinium, manganese, and titanium react on the surface of barium titanate crystal grains to form a shell portion in the form of a perovskite mixed compound, which is considered to be Gd(Ti, Mn)O3. As a result, the resulting dielectric ceramic composition not only reduces the range of capacitance variation caused by changes in firing temperature but also prevents the movement of oxygen defects within grain boundaries and shell portions, thereby preventing a decrease in resistivity and improving electrical durability.

[0048] Even more preferably, it is desirable to adjust the amount of gadolinium and the amount of manganese so that 0.005 ≦ y ≦ 0.02 and 0.005 ≦ z ≦ 0.02 are satisfied. This prevents excessive solid dissolution of excess gadolinium in crystal grains made of barium titanate in the dielectric ceramic composition and deposition of excess manganese on the surface of the dielectric ceramic composition. This further reduces the range of capacitance variation due to changes in firing temperature and maintains high resistivity.

[0049] In addition to additives containing gadolinium, manganese, and titanium, silicon may be added in an amount of 0.2 mol or more and 5.0 mol or less based on silicon (SiO2) such that the Si / Ti element ratio a, which is the element ratio of silicon to the titanium content, satisfies 0.002 ≦ a ≦ 0.05. Further, magnesium may be added in an amount of 0 mol or more and 5.0 mol or less based on magnesium oxide (MgO) such that the Mg / Ti element ratio b, which is the element ratio of magnesium to the titanium content, satisfies 0.00 ≦ b ≦ 0.05. With these additives, the dielectric ceramic composition produces first crystal grains 41 containing silicon and / or second crystal grains 42 that become glass grains, and creates a liquid phase inside during firing, so that a ceramic with higher density is produced at a lower temperature.In addition, by adding magnesium oxide, a shell part in the form of Gd(Mg, Ti, Mn)O3 or (Gd, Ba)(Mg, Ti, Mn)O3 can be formed, which further prevents movement of oxygen defects within the grain boundaries and the shell portion, thereby preventing a decrease in resistivity.

[0050] Even more preferably, it is desirable that 0.005 ≦ a ≦ 0.02, and it is desirable that 0.002 ≦ b ≦ 0.02. Under these conditions, excessive additives can be prevented from being generated as the third crystal grains 43, and a decrease in the relative dielectric constant, the effect of low-temperature densification, and a decrease in the resistivity can be prevented.

[0051] Of the first transition metal elements, the second transition metal elements, and the third transition metal elements, the rare earth elements are cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. By using these rare earth elements as additives, the rare earth element is solid-dissolved from the interface to the interior of the first crystal grains 41 in the firing temperature range of 1000°C to 1400°C, so that the dielectric ceramic composition is formed, and it becomes possible to obtain crystal grains having a core-shell structure including a shell portion and a core portion.

[0052] Generally, in a core-shell structure, as the firing temperature increases, more of the various additives in the crystal grains made of barium titanate are solid-dissolved, and the shell portion tends to become thicker. In the shell portion, a large capacitance region, which would occur at about 125°C near the Curie temperature of barium titanate, appears at a temperature close to room temperature. As a result, the capacitance in the practical temperature range close to room temperature changes greatly depending on the thickness of the shell portion. Therefore, to maintain the capacitance of a multilayer ceramic capacitor, for example, within a desired range, it is necessary to precisely control or adjust the firing temperature.

[0053] The dielectric ceramic composition according to the present embodiment is produced by firing at a temperature of 1000 °C to 1300 °C and by rapidly increasing the temperature during the firing process at a rate of 3000 °C / hour to 10000 °C / hour.

[0054] The first crystal grain 41 having a core-shell structure in which a shell portion 412 containing a rare earth element and manganese is formed has a manufacturing process different from that of a conventional core-shell structure. Specifically, in addition to the solid solution of the rare earth element in the barium titanate crystal particles, the rare earth element, manganese, and titanium added react on the surface of the barium titanate crystal particles to form a shell portion in the form of a perovskite complex compound such as Gd(Ti, Mn)O3.

[0055] Furthermore, added magnesium may react on the surface of the barium titanate crystal grains to form the shell portion 412 in the form of a perovskite complex compound such as Gd(Mg, Ti, Mn)O3.

[0056] The shell portion 412 in the form of a perovskite complex compound, which is considered to be Gd(Ti, Mn)O3 or Gd(Mg, Ti, Mn)O3, may be formed to react with barium titanate crystal particles, which are the main component of the environment, so that a shell portion made of (Gd, Ba)(Ti, Mn)O3 or (Gd, Ba)(Mg, Ti, Mn)O3 is formed.

[0057] For example, the core portion 411 in the core-shell structure is predominantly composed of crystal grains made of barium titanate, but may also contain rare earth elements, manganese, magnesium, etc., added. However, it is sufficient, for example, that the shell portion 412 contains relatively more rare earth elements, manganese, magnesium, etc., among the additives than the core portion 411.

[0058] In particular, the crystal grains of the present embodiment have a core-shell structure in which the main components are crystal grains consisting of barium titanate and a shell containing gadolinium and manganese, and comprise gadolinium and manganese in relatively higher amounts in terms of element ratios to titanium at any point within 10% of the diameter of the crystal grains from the grain surface, compared with the element ratios in the center of the grain.Due to the presence of crystal grains having such a core-shell structure, the polycrystalline body constituting the dielectric ceramic composition not only reduces the range of change in capacitance it maintains due to changes in firing temperature, but also prevents oxygen defects from moving in the grain boundaries and within the shell portion, thereby preventing a reduction in resistivity and improving electrical durability.

[0059] Here, the average grain diameter of the first crystal grains 41 in the dielectric ceramic composition is within the range of 50 nm to 500 nm, and very large grains of 3 μm or more are not retained in the portion electrically used as a dielectric. For example, in the dielectric ceramic composition, the maximum grain size of the first crystal grains is preferably 2 μm or less. Considering the general characteristic of ceramics that the particle diameter and composition distribution of the crystal grains therein are within a relatively narrow range, if it can be confirmed that some of the first crystal grains 41 have a core-shell structure, it can be considered that a large number of first crystal grains 41 with a similar structure exist and exert positive effects on the electrical durability of the dielectric ceramic composition.

[0060] The particle diameter of the first crystal grains 41 can be measured by the following method. The dielectric ceramic composition containing the first crystal grains 41 is cut or polished to expose an inspection surface. This exposure method is not particularly limited, and any method of cutting or polishing the device can be used. At this time, in order to fully examine the internal ceramic structure, it is preferable to obtain a smoothness that can be regarded as a mirror surface by using a diamond paste of 2 μm or less or the like. Next, after depositing a conductive substance such as platinum or osmium on the inspection surface, an examination is performed using a scanning electron microscope (SEM), and a photograph of the first crystal grains 41 is taken.Next, a plurality of mutually parallel straight lines are plotted on the captured photograph, and the length of the line segment intersected by each straight line at the periphery of each first crystal particle 41 (the distance between two intersection points where each straight line crosses the periphery of the first crystal particles 41) is measured as the grain diameter (grain size) of the first crystal grains 41. Using this method, the grain size of the first crystal grains 41 is measured for 400 or more grains, and the average of the obtained result is used as the average grain size of the first crystal grain 41. In addition, if the outline of the first crystal grains 41 is difficult to discern in the exposed ceramic, the exposed ceramic may be heated for about 5 minutes at a temperature about 50°C lower than that at which it was heated before the vapor deposition of platinum, osmium, etc., has been fired. Instead of this heat treatment, chemical etching may be used using hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, or a mixture thereof in a suitable concentration for etching.

[0061] The core-shell structure of the first crystal grain 41 is formed by adding gadolinium, manganese, and titanium, which react on the surface of barium titanate crystal grains to form a perovskite complex compound, which is considered to be Gd(Ti,Mn)O3, Gd(Mg,Ti,Mn)O3, (Gd,Ba)(Ti,Mn)O3, or (Gd,Ba)(Mg,Ti,Mn)O3, as the shell portion. At this time, since the added titanium participates in the reaction, the solid solution reaction to the barium titanate crystal grains is relatively suppressed compared to the case where titanium is not added. Due to this, when this material is used for multilayer ceramic capacitors requiring high mass production, for example, firing can be achieved in a shorter time while reducing the range of change in capacitance due to changes in firing temperature, thereby achieving high mass productivity.

[0062] The presence of the first crystal grains 41 having a core-shell structure in the dielectric ceramic composition can be confirmed by the following process.

[0063] First, a sample is cut out of the dielectric ceramic composition to be evaluated for transmission electron microscopy (TEM). This cutting can be performed using a focused ion beam (FIB) device or the like.

[0064] Next, the cut sample for TEM examination is examined using a TEM equipped with an energy dispersive X-ray spectrometer (EDS) or a wavelength dispersive X-ray spectrometer (WDS) to determine the crystal grains to be measured and simultaneously determine the outer peripheral shape of the grains.

[0065] Next, as stated in the Fig.As shown in Figure 3, of the line segments connecting any two points located on the outer circumference of the crystal grain to be measured, the one with the maximum length is determined, and the length L of the line segment is measured. This length L is then used as the diameter of the crystal grain to be measured. Furthermore, the center point M of the line segment is determined from the obtained length of the line segment.

[0066] Then, a composition analysis is performed using EDS or WDS with any point C on the outer circumference within a length range of 10% of the crystal grain diameter, i.e., 10L / 100, from both ends of the projecting line segment, so that the element abundance ratio of the target element with respect to the element titanium is obtained. Composition analysis, for example, an EDS measurement, can be performed by evaluating the intensity of the K line of titanium relative to the intensity of the K line or L line of barium, the intensity of the L line of gadolinium, and the intensity of the K line of manganese. Specifically, these intensities are subjected to a correction (ZAF correction) that takes into account the atomic number effect, the absorption effect, and the fluorescence excitation effect, and the ratio of each element content with respect to titanium is calculated for the shell portion 412.Further, the composition analysis is performed accordingly for the center point M of the above line segment to calculate the ratios of each element with respect to titanium in the core portion 411.

[0067] Then, the ratio of each element to titanium in the shell part 412 and the ratio of each element to titanium in the core part 411 were compared, and when the ratios in the shell part 412 were higher than in the core part 411, it was determined that the crystal particles 41 had a core-shell structure.

[0068] In addition to the first crystal grains 41, the dielectric ceramic composition comprises, as second crystal grains 42 different from the first crystal grains 41, at least one second crystal particle 42 made of a barium titanate complex oxide in which the element ratio of barium to titanium is 0.70 or less.

[0069] In the second crystal grains 42, the element ratio of barium to titanium is preferably 0.16 or more. Furthermore, the second crystal grains 42 may contain manganese. The element ratio of manganese to titanium in the second crystal grains may be 0.02 or more and 0.10 or less, or 0.02 or more and 0.05 or less.

[0070] Examples of the second crystal grains 42 include BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O 13 , Ba4Ti 11 O 26 , Ba4Ti 12 O 27 , Ba4Ti 13 O 30 , Ba6Ti 17 O 40 and the like.

[0071] As can be seen from their composition formula, the second crystal grains 42 are a barium titanate complex oxide with a smaller amount of barium than in barium titanate. As described above, in the dielectric ceramic composition according to the present embodiment, since the shell portion 412 is formed of a perovskite complex compound assumed to be in the form of Gd(Ti,Mn)O3, Gd(Mg,Ti,Mn)O3, or (Gd,Ba)(Ti,Mn)O3, the second crystal grains 42 are produced as a by-product when an additive containing titanium as the main component is used. By intentionally depositing the second crystal grains 42 during the formation of the first crystal grains 41, for example,In a multilayer ceramic capacitor requiring high mass productivity, the range of change in capacitance due to a change in firing temperature can be reduced, and high mass productivity can be achieved. Furthermore, in the dielectric ceramic composition according to the present embodiment, which includes the second crystal grains 42, firing at a relatively high temperature is required to form the shell portion 412 in the form of the above-described perovskite complex compound. When firing is performed at a temperature rise rate of at most 10°C / min (600°C / hour) as disclosed in Patent Document 1 and Patent Document 2, it has been confirmed that the second crystal grains 42 grow large and exceed 10 μm, so that very large grains are produced.To eliminate this, it is preferable that the dielectric ceramic composition according to the present embodiment is rapidly heated at a rate of 3000 °C / hour to 10000 °C / hour so as to minimize the heat energy added to the firing process, thereby performing the firing process while preventing grain growth.

[0072] A preferred example of the second crystal grains 42 is a barium titanate complex oxide represented by Ba4Ti 11 O 26which is monoclinic and has a space group C2 / m, and lattice constants a = 15.160 Å, b = 3.893 Å, and c = 9.093 Å with β = 98.6°. This is due to the fact that this barium titanate complex oxide has a barium to titanium ratio relatively close to 1 and can be easily deposited intentionally without using a large amount of additives whose main component is titanium. This barium titanate complex oxide is described, for example, in the non-patent document Acta Cryst. (1979), B35, 1590-1593.

[0073] As a more preferable example of the second crystal grains 42, it is preferable that manganese is dissolved as a solid solution in Ba a Ti 11 O 26 which covers its defect areas or replaces some of the titanium. As can be seen from the above-mentioned non-patent document, Ba4Ti 11 O 26a crystal structure in which some titanium positions have defects. Therefore, titanium tends to change from a tetravalent cation to a trivalent cation at the defect site, and as a result, the resistivity tends to decrease. To complement this, it is effective to include manganese in solid solution.

[0074] Here, whether the dielectric ceramic composition contains the second crystal grains 42 or not can be determined by the following procedure.

[0075] First, the diffraction line profile of the surface of the dielectric ceramic composition to be evaluated or the powder obtained by crushing the dielectric ceramic composition to be evaluated is measured using an X-ray diffractometer (XRD) using Cu-Kα rays. The pulverization method for obtaining the powder is not particularly limited, and a hand-held crusher (mortar / pestle) or the like can be used. Furthermore, when measuring the diffraction profile of the ceramics constituting a multilayer ceramic capacitor, it is necessary to remove the electrodes and coatings formed on the surface of the device, as well as parts other than the dielectric layers of the multilayer ceramic capacitor, thereby exposing the surface of the dielectric ceramic composition.This exposure method is not specifically limited, and any method of cutting or polishing the device can be used. Furthermore, when measuring the diffraction profile of the powder of the dielectric ceramic composition constituting the multilayer ceramic capacitor, the electrodes and coatings formed on the device, as well as parts other than the dielectric layer of the multilayer ceramic capacitor, are preferably removed before crushing.

[0076] Next, in the obtained diffraction profile, the percentage of the strongest diffraction line intensity originating from other structures relative to the strongest diffraction line intensity originating from the perovskite structure is calculated. If the ratio is 10% or less, it is determined that the dielectric ceramic composition to be evaluated is composed of first crystal grains 41 having a perovskite structure. Furthermore, when the surface of the dielectric ceramic composition of a multilayer ceramic capacitor is exposed using the above method, or when XRD measurement is performed on a pulverized powder, peaks of the materials constituting the electrodes and coatings may also be detected. Therefore, the above-mentioned diffraction line intensity ratio is calculated after excluding them.

[0077] Next, the crystal phase is evaluated by focusing on peaks that differ from the diffraction line intensities originating from the perovskite structure. When doing this, it is preferable to refer to the PDF (powder diffraction data) published by the ICDD (International Centre for Diffraction Data; Pennsylvania, USA) to search for and identify the second crystal grains 42. In the case of Ba4Ti 11 O 26 as a preferred example, its preparation can be evaluated by identifying it with reference to PDF-01-083-1459.

[0078] Next, it is determined whether or not the second crystal particles 42 are made of a barium titanate complex oxide in which the element ratio of barium to titanium is 0.70 or less using the following method.

[0079] First, the surface of the dielectric ceramic composition is exposed. This exposure method is not specifically limited, and any method of cutting or polishing the device can be used. To fully examine the internal ceramic structure, it is preferable to use a diamond paste of 2 μm or less or the like to achieve a smoothness that can be judged as a mirror surface.

[0080] Next, an energy dispersive X-ray spectrometer (EDS) or a wavelength dispersive X-ray spectrometer (WDS) attached to a scanning electron microscope (SEM) or a transmission electron microscope (TEM), or an electron probe microanalyzer (EPMA), or laser irradiation inductively coupled plasma mass spectrometry (LA-ICP-MS), or the like is used to analyze the composition of the second crystal grains 42.

[0081] For example, in an EDS measurement, the intensity of the K-line of titanium relative to the K-line or L-line of barium or the K-line of manganese can be used to analyze the composition. Specifically, these intensities are subjected to a correction (ZAF correction) that takes into account the atomic number effect, the absorption effect, and the fluorescence excitation effect, and the ratio of each to the elemental content of titanium is calculated.

[0082] When performing EDS measurements, especially when using the Lα rays of barium and the Kα rays of titanium, their energy peaks are close to each other, and it may be difficult to adequately compare the element contents. For this reason, it is preferable that the Lβ2 line and the Lβ1β2 line of barium, which have no peak overlap, be obtained with sufficient intensity for measurement. In particular, it is preferable that the intensity at the peak be 10,000 counts or more. In this way, the intensity of the characteristic X-rays of barium can be determined and the element content can be calculated, so that even if the Lα line of barium and the Kα line of Ti overlap, the intensity of the Kα rays of titanium can be determined and the element content can be evaluated with high accuracy.

[0083] When the element ratio of barium to titanium obtained by the above method is 0.70 or less, the evaluated crystal grain is determined to be the second crystal grain 42. That is, it is determined to be one of the above-mentioned barium titanate complex oxides based on the fact that the element ratio of barium to titanium is lower than that of the first crystal grain 41 made of barium titanate present in the environment. Meanwhile, when an SEM is used for observation, the second crystal grains 42 have a relatively low brightness (i.e., a darker image) than the first crystal grain 41 when observed using a backscattered electron image (BSE image). Furthermore, as a more preferable evaluation method, the second crystal grains 42 can be evaluated using the diffraction profile by X-ray diffraction (XRD).

[0084] Specifically, the portion determined as the second crystal grain 42 is cut out as a sample for transmission electron microscope (TEM) examination, and a diffraction pattern obtained using a selected region diffraction method is obtained. By comparing it with literature data, it can be confirmed whether it is classified as one of BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O 13 , Ba4Ti 11 O 26 , Ba4Ti 12 O 27 , Ba4Ti 13 O 30 and Ba6Ti 17 O 40 can be determined. It should be noted that this excision can be performed using an FIB device or the like.

[0085] The solid solution of manganese in the second crystal grains 42 can be evaluated by the intensity of the K-line of titanium relative to the K-line of Mn by EDS, WDS, or EPMA. Specifically, ZAF correction is performed with these intensities to calculate the ratio w of the element content of manganese to the element content of titanium. It is preferable that the range is 0.02 ≦ w ≦ 0.10, more preferably 0.02 ≦ w ≦ 0.05. For example, manganese becomes a solid solution in the defect position of the Ti position in Ba4Ti. 11 O 26 and a reduction in the resistivity of the dielectric ceramic composition can be prevented.

[0086] Furthermore, the dielectric ceramic composition may contain third crystal grains 43 having a composition or crystal structure different from the first crystal grains 41 and the second crystal grains 42. Furthermore, the dielectric ceramic composition may contain silicon-containing crystal particles or glass particles. This allows the dielectric ceramic composition to be sufficiently densified by firing it at 1300°C or lower.

[0087] The third crystal grains 43 may generally be crystal particles or glass particles, such as silicate (SiO2), enstatite (MgSiO3), barium magnesium silicate (BaMgSiO4) or fresnoite (Ba2TiSi2O8).

[0088] In addition, examples of the third crystal grains 43 include compounds generated from added substances such as geikielite (MgTiO3), manganese nickel oxide ((Mn, Ni)O) and pyrophanite (MnTiO3), or compounds generated from electrodes. (Second embodiment)

[0089] As a second embodiment, a multilayer ceramic capacitor 100 using the dielectric ceramic composition according to the first embodiment will be described.

[0090] The Fig. 4 is a perspective partial cross-sectional view of the multilayer ceramic capacitor 100. The Fig. Figure 5 is a cross-sectional view taken along line AA in the Fig. 4. The Fig. 6 is a cross-sectional view taken along line BB in the Fig. 4. As it is in Fig.As shown in FIGS. 4 to 6, the multilayer ceramic capacitor 100 includes a multilayer chip 10 having a substantially rectangular parallelepiped shape and external electrodes 20a and 20b provided on two opposite end surfaces of the multilayer chip 10. It should be noted that, of the four surfaces of the multilayer chip 10 other than the two end surfaces, two surfaces other than the upper surface and the lower surface in the stacking direction are referred to as side surfaces. The external electrodes 20a and 20b extend on the upper surface, the lower surface, and two side surfaces of the stacked chip 10 in the stacking direction. However, the external electrodes 20a and 20b are spaced apart from each other.

[0091] The multilayer chip 10 has a structure in which dielectric layers 11 containing a dielectric ceramic composition and internal electrode layers 12 containing a base metal material are alternately laminated. The edges of each internal electrode layer 12 are alternately exposed on the end surface where the external electrode 20a of the multilayer chip 10 is provided and the end surface where the external electrode 20b is provided. Thus, the respective internal electrode layers 12 are alternately electrically connected to the external electrodes 20a and 20b. As a result, the multilayer ceramic capacitor 100 has a structure in which a plurality of dielectric layers 11 are stacked with internal electrode layers 12 therebetween.Furthermore, in the laminate of the dielectric layer 11 and the internal electrode layer 12, the internal electrode layer 12 is arranged as the outermost layer in the stacking direction, and the upper and lower surfaces of the laminate are each covered with capping layers 13. The capping layer 13 has a ceramic material as a main component. For example, the capping layer 13 has the same ceramic material as the dielectric layer 11.

[0092] The size of the multilayer ceramic capacitor 100 is, for example, 0.25 mm long, 0.125 mm wide, and 0.125 mm high, or 0.4 mm long, 0.2 mm wide, and 0.2 mm high, or 0.6 mm long, 0.3 mm wide, and 0.3 mm high, or 1.0 mm long, 0.5 mm wide, and 0.5 mm high, or 3.2 mm long, 1.6 mm wide, and 1.6 mm high, or 4.5 mm high, 3.2 mm wide, and 2.5 mm high, but the size is not limited thereto.

[0093] The inner electrode layer 12 has a base metal such as Ni (nickel), Cu (copper), Sn (tin) as a main component. Noble metals such as Pt (platinum), Pd (palladium), Ag (silver), and Au (gold), or alloys containing these metals, can be used as the inner electrode layer 12.

[0094] As it is in the Fig. As shown in FIG. 4, the region where the inner electrode layer 12 connected to the outer electrode 20a and the inner electrode layer 12 connected to the outer electrode 20b face each other is a region where capacitance occurs in the multilayer ceramic capacitor 100. Therefore, the region where the electrical capacitance occurs is referred to as a capacitance region 14. That is, the capacitance region 14 is a region where adjacent inner electrode layers 12 connected to different outer electrodes face each other.

[0095] The region where the inner electrode layers 12 connected to the outer electrode 20a face each other without the inner electrode layer 12 connected to the outer electrode 20b being interposed is referred to as the end edge 15. Further, an end edge 15 is also a region where the inner electrode layers 12 connected to the outer electrode 20b face each other without the inner electrode layer 12 connected to the outer electrode 20a being interposed. That is, the end edge 15 is a region where inner electrode layers 12 connected to the same outer electrode face each other without the inner electrode layers 12 connected to the outer electrode being interposed. The end edge 15 is a region where no capacitance occurs.

[0096] As it is in the Fig. As shown in FIG. 6, in the multilayer chip 10, the area of ​​the two side surfaces of the multilayer chip 10 that reaches the internal electrode layer 12 is referred to as the side edge 16. That is, the side edge 16 is a region provided to cover the side ends of the plurality of stacked internal electrode layers 12 and extend to one of the two side surfaces in the stacked structure. The side edge 16 is also a region that does not generate capacitance.

[0097] In the multilayer ceramic capacitor 100 according to the present embodiment, at least a portion of the dielectric layer 11 in the capacitance region 14 includes the first crystal grains 41 arranged in the Fig. 2, and also includes the second crystal grains 42. Thereby, the rate of change of the capacitance due to changes in the firing temperature can be reduced and high mass productivity can be achieved.

[0098] Next, a method for manufacturing the multilayer ceramic capacitor 100 will be described. Fig. 7 is a diagram showing a flow of a method for manufacturing the multilayer ceramic capacitor 100. (Method for producing a raw material powder)

[0099] First, a dielectric ceramic composition for forming the dielectric layers 11 is prepared. The A-position element and the B-position element contained in the dielectric layer 11 are usually contained in the dielectric layer 11 in the form of a sintered body of ABO3 particles. For example, barium titanate is a compound having a perovskite structure and belonging to the tetragonal system near room temperature, having a high dielectric constant. This barium titanate can generally be synthesized by reacting a titanium raw material such as titanium dioxide with a barium raw material such as barium carbonate. For synthesizing barium titanate, which is the main component of the dielectric layer 11, various methods are conventionally known, such as a solid-phase method, a sol-gel method, and a hydrothermal method.In this embodiment, any of them can be used.

[0100] Predetermined additives are added to the barium titanate powder obtained by the above method. For example, additives within the range explained above in the example of the dielectric ceramic composition according to the first embodiment are used. Optionally, an oxide or glass containing Zr (zirconium), V (vanadium), Cr (chromium), Co (cobalt), Ni (nickel), Li (lithium), B (boron), Na (sodium), or K (potassium) may also be used. Also, an oxide of Sc (scandium), Y (yttrium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu (europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Y (ytterbium) or Lu (lutetium), as rare earth elements other than Gd, may optionally be added.

[0101] For example, a compound containing an additive compound may be wet-mixed with barium titanate powder, dried, and pulverized to produce a ceramic material in which barium titanate powder and the additive compound are mixed. For example, the ceramic material obtained in the manner described above may be pulverized to adjust the particle diameter, or it may be combined with a classification process to adjust the particle diameter. Specifically, beads with a diameter of 0.1 mm to 3 mm made of yttrium-stabilized zirconia, alumina, or silicon nitride may be stirred together with the ceramic material for 10 to 100 hours to adjust the particle diameter. Through the above steps, a dielectric ceramic composition is obtained. (coating process)

[0102] Next, a binder such as a polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the obtained dielectric ceramic composition and wet-mixed. Using the obtained slurry, a ceramic green sheet 51 is applied to a base material by, for example, a die coating method or a doctor blade method, and then dried. The base material is, for example, a polyethylene terephthalate (PET) film. Figures indicating the coating process are omitted. (Method for forming an inner electrode)

[0103] Next, as stated in the Fig.As shown in Figure 8(a), a conductive metal paste containing an organic binder for forming internal electrodes is printed on the surface of the ceramic green sheet 51 by screen printing, gravure printing, etc., to form internal electrode patterns 52, which are alternately arranged to form a pair of external electrodes. Ceramic particles are added to the conductive metal paste as an additional material. Although the main component of the ceramic particles is not specifically limited, it is preferably the same as the main component of the ceramic of the dielectric layer 11. For example, barium titanate having an average particle diameter of 50 nm or less can be uniformly dispersed.

[0104] Next, a binder such as ethylcellulose and an organic solvent such as terpineol are added to the dielectric ceramic composition obtained in the process for preparing the raw material powder, and the mixture is kneaded in a roll mill to form a dielectric pattern paste for the reverse pattern layer. As described in the Fig. As shown in Fig. 8(a), the dielectric pattern 53 is arranged on the ceramic green sheet 51 by printing a dielectric pattern paste in the peripheral region, with the internal electrode pattern 52 not printed, so that the internal electrode pattern 53 is arranged so that one step is filled with the internal electrode pattern 52. The ceramic green sheet 51 on which the internal electrode pattern 52 and the dielectric pattern 53 are printed is referred to as a lamination unit.

[0105] Afterwards, as stated in the Fig.As shown in Figure 8(b), the lamination units are stacked such that the inner electrode layers 12 and the dielectric layers 11 are alternately arranged, and the edges of the inner electrode layers 12 are alternately exposed and alternately exposed to a pair of outer electrodes 20a and 20b with different polarities. For example, the number of stacked layers of the inner electrode structure 52 is set to 100 to 1000 layers. (pressing process)

[0106] As it is in the Fig.As shown in Fig. 9, a predetermined number (for example, 2 to 10 layers) of cover layers 54 are laminated onto the top and bottom surfaces of the laminate in which the lamination units have been laminated, and are bonded by hot pressing. As an example of the ceramic material for the cover layer 54, the above-described dielectric ceramic composition can be used. Thereafter, it is cut into a predetermined chip size (for example, 1.0 mm x 0.5 mm). At this time, the side edge portions may instead be attached or coated onto the side surfaces of the laminate. In particular, as shown in Fig. Fig.As shown in FIG. 10, a laminated body can be obtained by alternately laminating ceramic green sheets 51 and internal electrode patterns 52 having the same width as the ceramic green sheets 51. Then, layers of the dielectric pattern paste can be laminated as the side edge portions 55, respectively, onto the side surfaces of the laminated body. (burning process)

[0107] After debinding the thus obtained ceramic laminate in an N2 atmosphere, air atmosphere, etc., a metal paste, which becomes the base layer of the external electrodes 20a, 20b, is applied by a dipping method, and the resulting laminate is heated in a reducing atmosphere with an oxygen partial pressure of 10 -12 atm to 10 -9Atm at 1100°C to 1300°C for 10 minutes to 2 hours. In this way, the multilayer ceramic capacitor 100 is obtained. It should be noted that the temperature rises rapidly in the firing step. The temperature rise rate in the firing step is, for example, 6000°C / hour. As a result, the second crystal grains 42 do not become very large particles, and furthermore, the time required for firing can be significantly shortened, and higher mass productivity can be achieved. (treatment process for re-oxidation)

[0108] Afterwards, a re-oxidation treatment can be carried out at 600 °C to 1000 °C in a N2 gas atmosphere. (plating process)

[0109] Subsequently, a metal coating such as Cu, Ni, Sn, etc., is applied to the base layer of the outer electrodes 20a, 20b by plating. Through the above steps, the multilayer ceramic capacitor 100 is completed.

[0110] According to the manufacturing method of the present embodiment, the first crystal grains 41 formed in the Fig. 2, and the second crystal grains 42 are incorporated into at least a portion of the dielectric layer 11 of the capacitance region 14. In multilayer ceramic capacitors requiring high mass productivity, the rate of change in capacitance due to changes in firing temperature can be reduced, and high mass productivity can be achieved.

[0111] The firing temperature dependence (Δε / °C) of the dielectric constant due to changes in the firing temperature of the multilayer ceramic capacitor 100 is evaluated by the following method. First, the capacitance Cp (nF) and the direct current I (nA) are measured for the multilayer ceramic capacitor 100 that has undergone the firing process, the re-oxidation process, and the plating process. Next, in the multilayer ceramic capacitor 100, the capacitance region 14 is exposed by cutting or polishing, etc., on the AA-line cross-section and the BB-line cross-section shown in the Fig. 5 and Fig. 6, and the exposed surfaces are polished using a diamond paste of 2 μm or less or the like to achieve a smoothness that can be considered a mirror surface. The effective area of ​​the inner electrode layer is evaluated using these surfaces.

[0112] The effective area S is determined from the length L and the number N of the inner electrode layers 12 in the capacity region 14 in the Fig. 5 and the width W of the inner electrode layers 12 in the capacity region 14 in the Fig. 6 is determined as follows: S = L × W × (N - 1)

[0113] The thickness of each dielectric layer 11 is also measured and the average thickness t is calculated. The relative dielectric constant ε can be calculated according to ε = (Cp × t / S) / ε0 with the vacuum dielectric constant: ε0 = 8.8542 × 10 -12 F / m can be calculated.

[0114] Furthermore, the specific DC resistance ρ (Ω cm) can be calculated according to ρ = (V / I) × (S / t), where the DC voltage at the measurement is V (V).

[0115] Regarding the capacitance Cp, it is generally preferable to measure it using an LCR meter. During measurement, it is necessary to determine the measurement frequency and the measurement voltage, but it is preferable that the measurement voltage be determined as the electric field for measurement. In this embodiment, the capacitance Cp is measured at room temperature of 25°C with a measurement frequency of 1 kHz and an electric field for measurement of 0.5 Vrms / µm. That is, when the thickness of the dielectric layer 11 is 2 µm, 1 Vrms is applied to measure the capacitance Cp.

[0116] Regarding the direct current I, it is generally preferable to measure it using an insulating resistance meter. In the measurement, it is necessary to determine the measurement voltage, but it is preferable to determine the electric field for measurement depending on the thickness of the dielectric layer 11. In this embodiment, the multilayer ceramic capacitor 100 is kept in a constant temperature chamber at 150°C for 30 minutes, insulation from the environment is ensured using a ceramic insulator, etc., and the direct current is measured by applying an electric field for measurement of 30 V / μm (for example, 60 V for 30 seconds when the thickness of the dielectric layer 11 is 2 μm) through the wires connected to the external electrodes 20a and 20b, so that the direct current resistivity ρ is calculated.Unless otherwise specified, measurements are carried out in accordance with Japanese Industrial Standard C5101-22:2021 Fixed capacitors for electronic equipment - Part 22: General rules for types - Fixed multilayer ceramic capacitors for surface mount type 2.

[0117] Next, the DC resistivity ρ is measured for each of the multilayer ceramic capacitors obtained at different firing temperatures, and the firing temperature that maintains the highest resistivity is determined as the optimal firing temperature. Generally, if the firing temperature is too low, the density will be low and the resistivity will be low; if the firing temperature is too high, the ceramic particles will become larger and the number of grain boundaries will decrease, resulting in a decrease in the resistivity.

[0118] Next, based on the dielectric constant ε of the multilayer ceramic capacitor obtained at the firing temperature maintaining the highest resistivity and on the basis of the measured dielectric constants of the multilayer ceramic capacitor obtained in a firing temperature range different from the firing temperature maintaining the highest resistivity from -20 °C to +20 °C, the slope of the straight line fitting the relationship between the relative dielectric constants and the firing temperatures is obtained using the least squares method, so that the slope of the straight line representing the firing temperature dependence of the relative dielectric constant (Δε / °C) is calculated and used as an index of high mass productivity.

[0119] It is preferred that the DC resistivity measured at 150 °C is 2.0 × 10 8 Ω cm or more. With a resistance of 2.0 × 10 8 Ω cm or more, the multilayer ceramic capacitor 100 containing the dielectric ceramic composition of this embodiment can have sufficient resistance.

[0120] It is more preferable that the DC resistivity measured at 150 °C is 1.0 × 10 10 Ω · cm or more. Because they have a resistance of 1.0 × 10 10 Ω cm or more, the multilayer ceramic capacitor 100 using the dielectric ceramic composition of this embodiment not only has sufficient resistance but also has a thinner profile design and can easily increase the number of internal electrodes.

[0121] It is preferable that Δε / °C is 12 or less. With this value or less, in the multilayer ceramic capacitor 100 using the dielectric ceramic composition of this embodiment, firing can be achieved in a shorter time while also reducing changes in capacitance due to changes in firing temperature, thereby achieving high mass productivity.

[0122] Furthermore, Δε / °C is preferably 6 or less. With this value of 6 or less, the multilayer ceramic capacitor 100 using the dielectric ceramic composition of the present embodiment can achieve firing in a shorter time while also reducing changes in capacitance due to changes in firing temperature, thereby achieving high mass productivity.

[0123] It is preferable that the dielectric constant ε is 2500 or more. Even if the DC resistivity measured at 150 °C is 2.0 x 10 8 Ω cm or more and the firing temperature dependence Δε / °C of the relative dielectric constant is 12 or less, if ε is small, the electrostatic capacitance Cp reaches an insufficient value, resulting in properties unsuitable for use in the multilayer ceramic capacitor 100 employing the dielectric ceramic composition.

[0124] It should be noted that in each of the above embodiments, a multilayer ceramic capacitor has been described as an example of a multilayer ceramic electronic component, but the present invention is not limited thereto. For example, other multilayer ceramic electronic components, such as varistors and thermistors, may be used. Work examples (Work example 1)

[0125] A barium titanate powder with an average particle diameter of 150 nm was prepared, and 0.75 mol of Gd2O3, 0.5 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added per 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.995.

[0126] A dielectric slurry was prepared by mixing the dielectric ceramic composition with ethanol, toluene, and PVB (polyvinyl butyral) resin. This slurry was formed into a ceramic green sheet using a die coater. After drying, this ceramic green sheet was printed with a nickel paste to form an internal electrode pattern. The resulting laminated units were laminated, and thick layers of ceramic green sheets, on which no internal electrode pattern was formed, were pressed onto the top and bottom surfaces of the laminate and then cut into small pieces. Next, a nickel paste was dipped onto the two end surfaces as a conductive paste for external electrodes, and degreasing was performed in a nitrogen gas atmosphere.The degreased part was fired and reduced in a reducing atmosphere adjusted to a partial pressure of oxygen that did not oxidize nickel. The firing temperature was 1220 °C.

[0127] The resulting multilayer ceramic capacitor was 1005-shaped (1.0 mm x 1.0 mm x 0.5 mm). A re-oxidation treatment was then performed at 950 °C. Afterward, plating was performed to form a Cu plating layer, a Ni plating layer, and an Sn plating layer on the surface of the base layer, thus obtaining a multilayer ceramic capacitor. The average thickness of the dielectric layer 11 was 2.0 µm. (Working example 2)

[0128] In Working Example 2, 0.75 mol of Gd2O3, 1.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.990. The firing temperature was 1230 °C. Other conditions were identical to those in Working Example 1. (Working example 3)

[0129] In Working Example 3, 0.75 mol of Gd2O3, 2.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.980. The firing temperature was 1240 °C. Other conditions were identical to those in Working Example 1. (Working example 4)

[0130] In Working Example 4, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. (Working example 5)

[0131] In Working Example 5, 0.75 mol of Gd2O3, 8.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.926. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. (Comparison example 1)

[0132] In Comparative Example 1, based on 100 mol of barium titanate powder, Gd2O3 was not added, and 1.5 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to prepare a dielectric ceramic composition. The Ba / Ti element ratio was 0.985. The firing temperature was 1220 °C. Other conditions were identical to those in Working Example 1. (Comparison example 2)

[0133] In Comparative Example 2, 0.75 mol of Gd2O3, 0.2 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.998. The firing temperature was 1210 °C. Other conditions were identical to those in Working Example 1.

[0134] For each of the multilayer ceramic capacitors of Working Examples 1 to 5 and Comparative Examples 1 and 2, the capacitance Cp was measured at room temperature (25 °C) at 1 kHz and 1 Vrms using an LCR meter, and the direct current I was measured at 150 °C by applying 60 V for 30 seconds using an insulating resistance meter. Furthermore, the effective area S of the inner electrode layers and the average thickness t of the dielectric layers were measured by exposing the cross section along line AA and the cross section along line BB in the Fig.4. The relative dielectric constant ε and the specific resistance ρ were calculated from the effective area S and the average thickness t. Then, the specific resistances ρ of each multilayer ceramic capacitor of Working Examples 1 to 5 and Comparative Examples 1 and 2 were compared, and by referring to the dielectric constants of the multilayer ceramic capacitors fired in a temperature range of -20 °C to +20 °C from the firing temperature at which the multilayer ceramic capacitor had the highest specific resistance, and by obtaining the slope of the relationship between the firing temperature and the dielectric constant using the least squares method, a firing temperature dependence of the dielectric constant (Δε / °C) was obtained.

[0135] Furthermore, a conductive substance, such as osmium, was deposited on the exposed dielectric layer, and a photograph of the crystal grains present in the dielectric layer was taken by SEM. The average particle diameter of the crystal grains forming the dielectric layer was then calculated.

[0136] Furthermore, during an SEM examination of the multilayer ceramic capacitor, the presence of second crystal grains 42 in the BSE image was evaluated based on the brightness difference. For parts found to be dark with relatively low brightness, it was determined using the EDS composition evaluation method whether the crystal grain was made of a barium titanate complex oxide with a barium to titanium element ratio v of 0.70 or less. Furthermore, the manganese to titanium element ratio for this part was also evaluated, and it was evaluated whether the Mn / Ti element ratio w satisfied 0.02 ≦ w ≦ 0.10.

[0137] For each multilayer ceramic capacitor, to confirm the composition of the shell portion and the core portion of the crystal grains of the dielectric layer, a sample was cut out by FIB for EDS examination using a TEM, and a composition evaluation method using EDS was performed to determine whether it had a core-shell structure.

[0138] Furthermore, for exemplary samples of each multilayer ceramic capacitor, the cap layers, end edges, side edges, and outer electrodes outside the capacitance portion were removed by polishing or cutting, and then the dielectric layer forming the capacitance region was ground to form a powder. The diffraction profile of the powder was then measured with an X-ray diffractometer (XRD) using Cu-Kα rays to evaluate whether second crystal grains 42, which were identified as Ba4Ti, were present.11 O 26 can be identified.

[0139] Table 1 summarizes the amounts of additives added in Comparative Examples 1 and 2 and Working Examples 1 to 5, as well as the firing temperature, average particle diameter, ε, Δε / °C and resistivity at 150 °C. [Table 1] Amount added per 100 mol BaTiO3(mol) Ba / Ti element ratio Firing temperature (°C) Average particle diameter (nm) ε Δε / °C Specific resistance at 150 °C Ω cm Gd2O3 TiO2 MnCO3 SiO2 MgO Comparison example 1 0 1,5 1,5 1,0 0,0 0,985 1220 2400 2820 1,0 - Comparison example 2 0,75 0,2 1,5 1,0 0,0 0,998 1210 520 4400 12,5 2,6 × 10 10 Working example 1 0,75 0,5 1,5 1,0 0,0 0,995 1220 450 3930 10,0 2,0 × 10 10 Working example 2 0,75 1,0 1,5 1,0 0,0 0,990 1230 430 3830 2,5 1,4 × 10 10 Working example 3 0,75 2,0 1,5 1,0 0,0 0,980 1240 380 3630 0,8 6,9 × 10 9 Working example 4 0,75 4,0 1,5 1,0 0,0 0,962 1270 290 3200 0,3 1,4 × 10 9 Working example 5 0,75 8,0 1,5 1,0 0,0 0,926 1270 270 2520 1,5 3,5 × 10 8

[0140] Comparative Example 1 is a comparative example in which gadolinium, as a rare earth element, is not included. Comparative Example 2 is a comparative example in which the added amount of TiO2 is small—that is, at the lower limit. In Comparative Example 1, the particle diameter could not be controlled during firing, and the particle diameter grew to 2400 nm, resulting in low resistance because gadolinium was not included as a rare earth element. In Comparative Example 2, the average particle diameter was 520 nm, and the specific resistance at 150 °C was 2.6 × 10 10 Ω cm, which allowed sufficient resistivity to be maintained due to the inclusion of gadolinium as a rare earth element. However, since an insufficient amount of TiO2 was added, the Δε / °C value was 12.5, thus failing to achieve a preferred value of 12 or less.

[0141] In Working Examples 1 to 5, the amount of TiO2 added was 0.5 mol to 8.0 mol per 100 mol of BaTiO3, and the Ba / Ti element ratio x in the dielectric layer was in the range of 0.926 ≦ x ≦ 0.995. In this range, the value of Δε / °C was 12 or less. In particular, when the amount of TiO2 added was 1.0 mol or more, Δε / °C was 3 or less. For example, even when a larger kiln than existing kilns was used to increase manufacturing efficiency, the distribution of the relative dielectric constant caused by the temperature distribution within the kiln—that is, the distribution of the capacitance Cp within the kiln—did not exhibit a large distribution. For this reason, even with short-time firing, due to a rapid temperature rise, it is possible to achieve larger mass production.Furthermore, since the average particle diameter was 500 nm or less and the specific resistance was 2.0 × 10. 8 Ω cm or more, a preferential electrical lifetime was obtained.

[0142] To investigate the mechanism of the dielectric layers in detail, TEM-EDS, SEM-EDS and XRD measurements were carried out for each of the multilayer ceramic capacitors obtained in Working Examples 1 to 5 and Comparative Examples 1 and 2 to determine whether a core-shell structure exists, whether Ba4Ti 11 O 26 whether the element ratio v of Ba to Ti in the second crystal grain 42 is in the range of 0.16 ≦ v ≦ 0.70 and whether the element ratio w of Mn to Ti is in the range of 0.02 ≦ w ≦ 0.10. The results are summarized in Table 2. [Table 2] Was there a core-shell? Covering core Ba4Ti 11 O 28 found? Second crystal grain Gd / Ti element ratio Mn / Ti element ratio Gd / Ti element ratio Mn / Ti element ratio Ba / Ti element ratio Mn / Ti element ratio Comparison example 1 No - 0,011 - 0,004 Yes 0,45 0,03 Comparison example 2 Yes 0,031 0,035 0,001 0,004 No - - Working example 1 Yes 0,028 0,022 0,000 0,002 Yes 0,58 0,03 Working example 2 Yes 0,025 0,026 0,000 0,004 Yes 0,52 0,05 Working example 3 Yes 0,023 0,029 0,000 0,000 Yes 0,43 0,02 Working example 4 Yes 0,025 0,021 0,000 0,001 Yes 0,49 0,03 Working example 5 Yes 0,027 0,023 0,000 0,002 Yes 0,29 0,05

[0143] In Comparative Example 1, a core-shell structure was not found because it did not contain gadolinium, which is a rare earth element. Furthermore, the Mn / Ti ratio of the shell in Comparative Example 1 is the Mn / Ti ratio found at point C in the Fig. 3, and the Mn / Ti ratio of the core is the Mn / Ti ratio measured at the center point M in the Fig. 3 was measured. In comparative example 2, the presence of Ba4Ti 11 O 26 could not be obtained by XRD measurement because the amount of added TiO2 was insufficient. Furthermore, SEM-EDS could not confirm the presence of second crystal particles 42, which would be visible as dark and exhibit a relatively low brightness compared to the main crystal particles made of barium titanate.

[0144] On the other hand, in working examples 1 to 5, it was determined that a core-shell structure existed, Ba4Ti 11 O 26was present in X-ray diffraction (XRD), and the element ratio v of Ba to Ti and the element ratio w of Mn to Ti in the second crystal grains 42 were in the range of 0.16 ≦ v ≦ 0.70 and 0.02 ≦ w ≦ 0.10, respectively, so that the presence of the second crystal grains 42 was also evident. Furthermore, as shown in Table 1, the value of Δε / °C is 12 or less, and the specific resistance is 2.0 × 10 8 Ω cm or more, the average particle diameter is 500 nm or less, and the dielectric constant satisfied ε > 2500 or more.

[0145] To verify whether corresponding effects are obtained when the rare earth type, rare earth amount, manganese amount, silicon amount, and magnesium amount of the dielectric ceramic composition are adjusted, multilayer ceramic capacitors made of the above-described dielectric ceramic composition were manufactured as working examples within the scope of the present invention using the same procedures as those of Comparative Examples 1 and 2 and Working Examples 1 to 5. <Verifizierung des Effekts einer Änderung des Seltenerd-Typs> (Working example 6)

[0146] In Working Example 6, 0.75 mol of Eu2O3 (europium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1280 °C. The other conditions were identical to those in Working Example 1. (Working example 7)

[0147] In Working Example 7, 0.75 mol of Tb2O3 (terbium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 8)

[0148] In Working Example 8, 0.75 mol of Dy2O3 (dysprosium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 9)

[0149] In Working Example 9, 0.75 mol of Y2O3 (yttrium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 10)

[0150] In Working Example 10, 0.75 mol of Ho2O3 (holmium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1. (Working example 11)

[0151] In Working Example 11, 0.75 mol of Er2O3 (erbium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1. (Working example 12)

[0152] In Working Example 12, 0.75 mol of Yb2O3 (ytterbium oxide), 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1. (Working example 13)

[0153] In Working Example 13, 0.375 mol of Gd2O3, 0.375 mol of Dy2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 14)

[0154] In Working Example 14, 0.375 mol of Eu2O3, 0.375 mol of Ho2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 15)

[0155] In Working Example 15, 0.25 mol of Gd2O3, 0.25 mol of Tb2O3, 0.25 mol of Y2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1.

[0156] Working Examples 6 to 12 are cases where the rare earth type is changed to europium, terbium, dysprosium, holmium, erbium, and ytterbium, and Working Examples 13 to 15 are working examples of dielectric ceramic compositions in which two or more elements selected from the rare earth elements are added.

[0157] In Working Examples 6 to 15, the value of Δε / °C was 2 or less, and the relative dielectric constant was found to be sufficiently stable with respect to the firing temperature. Furthermore, the average particle diameter was 500 nm or less, and the specific resistance at 150 °C was 2.0 × 10 8 Ω cm or more. Therefore, even when firing in a short time due to a rapid temperature rise, mass production is possible and sufficient reliability can be maintained. <Verifizierung des Effekts der Menge von zugesetztem MnCO3>(Working example 16)

[0158] In Working Example 16, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 0.2 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1280 °C. Other conditions were identical to those in Working Example 1. (Working example 17)

[0159] In Working Example 17, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.0 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1280 °C. Other conditions were identical to those in Working Example 1. (Working example 18)

[0160] In Working Example 18, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 2.0 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1230 °C. Other conditions were identical to those in Working Example 1. (Working example 19)

[0161] In Working Example 19, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 5.0 mol of MnCO3, and 1.0 mol of SiO2 were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1210 °C. Other conditions were identical to those in Working Example 1.

[0162] Working Examples 16 to 19 are working examples of dielectric ceramic compositions in which the amount of MnCO3 added was varied in the range of 0.2 mol to 5.0 mol per 100 mol of BaTiO3. In Working Examples 16 to 19, the value of Δε / °C was 12 or less. In particular, when the amount of MnCO3 added was in the range of 1.0 mol to 5.0 mol, Δε / °C was 4 or less. In addition, the average particle diameter was also 500 nm or less, and the specific resistance was also 2.0 × 10 8Ω cm or more. Therefore, even if a larger kiln is used than existing kilns to increase manufacturing efficiency, the relative dielectric constant obtained with respect to the temperature distribution in the kiln, ie, the value of the capacitance Cp, does not exhibit a large distribution. Therefore, even with short-term firing due to a rapid temperature rise, mass production can be achieved and sufficient reliability can be maintained. <Verifizierung des Effekts der Menge von zugesetztem MgO> (Working example 20)

[0163] In Working Example 20, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.05 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. (Working example 21)

[0164] In Working Example 21, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.2 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1290 °C. Other conditions were identical to those in Working Example 1. (Working example 22)

[0165] In Working Example 22, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. (Working example 23)

[0166] In Working Example 23, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 1.0 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1260 °C. Other conditions were identical to those in Working Example 1. (Working example 24)

[0167] In Working Example 24, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 2.0 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1240 °C. Other conditions were identical to those in Working Example 1. (Working example 25)

[0168] In Working Example 25, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 5.0 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1230 °C. Other conditions were identical to those in Working Example 1.

[0169] Working Examples 20 to 25 are working examples of dielectric ceramic compositions in which the amount of MgO added was varied from 0.05 mol to 5.0 mol per 100 mol of BaTiO3.

[0170] In Working Examples 20 to 25, the value of Δε / °C was 2 or less, indicating that the dielectric constant was sufficiently stable with respect to the firing temperature. Furthermore, the average particle diameter was 500 nm or less, and the specific resistance was 2.0 × 10 8Ω cm or more. Therefore, even if a larger kiln than existing kilns is used to increase manufacturing efficiency, the relative dielectric constant obtained with respect to the temperature distribution in the kiln, ie, the capacitance Cp, does not exhibit a large distribution. Therefore, even with short-term firing due to a rapid temperature rise, mass production can be achieved and sufficient reliability can be maintained. <Verifizierung des Effekts der Menge von zugesetztem Gd2O3> (Working example 26)

[0171] In Working Example 26, 0.25 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1280 °C. Other conditions were identical to those in Working Example 1. (Working example 27)

[0172] In Working Example 27, 1.0 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1250 °C. Other conditions were identical to those in Working Example 1. (Working example 28)

[0173] In Working Example 28, 2.5 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1230 °C. Other conditions were identical to those in Working Example 1.

[0174] Working Examples 26 to 28 are working examples of dielectric ceramic compositions in which the amount of Gd2O3 added was varied in the range of 0.25 mol to 2.5 mol per 100 mol of BaTiO3.

[0175] In Working Examples 26 to 28, the value of Δε / °C was 2 or less, indicating that the dielectric constant was sufficiently stable with respect to the firing temperature. Furthermore, the average particle diameter was also 500 nm or less, and the specific resistance at 150 °C was also 2.0 × 10 8Ω cm or more. Therefore, even with short-term firing due to a rapid temperature rise, mass production can be achieved and sufficient reliability can be maintained. (Working example 29)

[0176] In Working Example 29, 0.25 mol of Eu2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1290 °C. The other conditions were identical to those in Working Example 1. (Working example 30)

[0177] In Working Example 30, 2.5 mol of Eu2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 31)

[0178] In Working Example 31, 0.25 mol of Tb2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1280 °C. The other conditions were identical to those in Working Example 1. (Working example 32)

[0179] In Working Example 32, 2.5 mol of Tb2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 33)

[0180] In Working Example 33, 0.25 mol of Dy2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 34)

[0181] In Working Example 34, 2.5 mol of Dy2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1. (Working example 35)

[0182] In Working Example 35, 0.25 mol of Y2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 36)

[0183] In Working Example 36, 2.5 mol of Y2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1240 °C. The other conditions were identical to those in Working Example 1. (Working example 37)

[0184] In Working Example 37, 0.25 mol of Ho2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 38)

[0185] In Working Example 38, 2.5 mol of Ho2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1240 °C. The other conditions were identical to those in Working Example 1. (Working example 39)

[0186] In Working Example 39, 0.25 mol of Er2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 40)

[0187] In Working Example 40, 2.5 mol of Er2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1240 °C. The other conditions were identical to those in Working Example 1. (Working example 41)

[0188] In Working Example 41, 0.25 mol of Yb2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1260 °C. The other conditions were identical to those in Working Example 1. (Working example 42)

[0189] In Working Example 42, 2.5 mol of Yb2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1240 °C. The other conditions were identical to those in Working Example 1. (Working example 43)

[0190] In Working Example 43, 0.125 mol of Gd2O3, 0.125 mol of Dy2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 44)

[0191] In Working Example 44, 1.25 mol of Gd2O3, 1.25 mol of Dy2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1250 °C. The other conditions were identical to those in Working Example 1. (Working example 45)

[0192] In Working Example 45, 0.125 mol of Eu2O3, 0.125 mol of Ho2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 46)

[0193] In Working Example 46, 1.25 mol of Eu2O3, 1.25 mol of Ho2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1240 °C. The other conditions were identical to those in Working Example 1. (Working example 47)

[0194] In Working Example 47, 0.08 mol of Gd2O3, 0.08 mol of Tb2O3, 0.09 mol of Y2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1270 °C. The other conditions were identical to those in Working Example 1. (Working example 48)

[0195] In Working Example 48, 0.8 mol of Gd2O3, 0.8 mol of Tb2O3, 0.9 mol of Y2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was 1230 °C. The other conditions were identical to those in Working Example 1.

[0196] Working Examples 26 to 48 are working examples of dielectric ceramic compositions in which the amount of rare earth element added was changed within the range of 0.25 mol to 2.5 mol per 100 mol of BaTiO3.

[0197] In Working Examples 26 to 48, the value of Δε / °C was 2 or less, indicating that the dielectric constant was sufficiently stable with respect to the firing temperature. Furthermore, the average particle diameter was 500 nm or less, and the specific resistance at 150 °C was 2.0 × 10 8Ω cm or more. Therefore, even with short-term firing due to a rapid temperature rise, mass production can be achieved and sufficient reliability can be maintained. <Verifizierung des Effekts der Menge von zugesetztem SiO2> (Working example 49)

[0198] In Working Example 49, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 0.2 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1290 °C. Other conditions were identical to those in Working Example 1. (Working example 50)

[0199] In Working Example 50, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 0.5 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1280 °C. Other conditions were identical to those in Working Example 1. (Working example 51)

[0200] In Working Example 51, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 2.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1220 °C. Other conditions were identical to those in Working Example 1. (Working example 52)

[0201] In Working Example 52, 0.75 mol of Gd2O3, 4.0 mol of TiO2, 1.5 mol of MnCO3, 5.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.962. The firing temperature was 1200 °C. Other conditions were identical to those in Working Example 1.

[0202] Working Examples 49 to 52 are working examples of dielectric ceramic compositions in which the amount of SiO2 added was varied from 0.2 mol to 5.0 mol per 100 mol of BaTiO3.

[0203] In Working Examples 49 to 52, the value of Δε / °C was 12 or less, indicating that the dielectric constant was sufficiently stable with respect to the firing temperature. Furthermore, the average particle diameter was also 500 nm or less, and the specific resistance at 150 °C was also 2.0 × 10 8Ω cm or more. Therefore, even with short-term firing due to a rapid temperature rise, higher mass production can be achieved and sufficient reliability can be maintained. <Verifizierung des Effekts der Zugabemenge von TiO2, wenn MgO zugesetzt wird> (Working example 53)

[0204] In Working Example 53, 0.75 mol of Gd2O3, 1.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.990. The firing temperature was 1230 °C. Other conditions were identical to those in Working Example 1. (Working example 54)

[0205] In Working Example 54, 0.75 mol of Gd2O3, 2.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.980. The firing temperature was 1240 °C. Other conditions were identical to those in Working Example 1. (Working example 55)

[0206] In Working Example 55, 0.75 mol of Gd2O3, 6.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.943. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. (Working example 56)

[0207] In Working Example 56, 0.75 mol of Gd2O3, 8.0 mol of TiO2, 1.5 mol of MnCO3, 1.0 mol of SiO2, and 0.5 mol of MgO were added to 100 mol of barium titanate powder to obtain a dielectric ceramic composition. The Ba / Ti element ratio was set to 0.926. The firing temperature was 1270 °C. Other conditions were identical to those in Working Example 1. [Table 3] Amount added per 100 mol BaTiO3 (mol) Ba / Ti element ratio Firing temperature (°C) Average particle diameter (nm) ε (Δε / °C) Specific resistance at 150 °C (Ω cm) Re2O3 (rare earth oxides) TiO2 MnCO3 SiO2 MgO Working example 6 Eu:0.75 - - - - 4,0 1,5 1,0 0,0 0,962 1280 280 3050 0,3 2,5 × 10 8 Working example 7 Tb:0.75 - - - - 4,0 1,5 1,0 0,0 0,962 1260 320 3300 0,4 3,0 × 10 9 Working example 8 Dy:0.75 - - - - 4,0 1,5 1,0 0,0 0,962 1260 330 3350 0,5 6,1 × 10 9 Working example 9 Y:0,75 - - - - 4,0 1,5 1,0 0,0 0,962 1260 340 3350 0,5 6,3 × 10 9 Working example 10 Ho:0.75 - - - - 4,0 1,5 1,0 0,0 0,962 1250 370 3180 0,6 3 × 10 10 Working example 11 Er:0,75 - - - - 4,0 1,5 1,0 0,0 0,962 1250 360 3150 0,6 4,7 × 10 10 Working example 12 Yb:0.75 - - - - 4,0 1,5 1,0 0,0 0,962 1250 250 2680 0,2 5,2 × 10 10 Working example 13 Gd:0.375 Dy:0.375 - - 4,0 1,5 1,0 0,0 0,962 1260 300 3230 0,4 4,1 × 10 9 Working example 14 Eu:0.375 Ho:0.375 - - 4,0 1,5 1,0 0,0 0,962 1270 330 3070 0,4 9,5 × 10 8 Working example 15 Gd:0.25 Tb:0.25 Y:0,25 4,0 1,5 1,0 0,0 0,962 1250 310 3200 0,3 5,5 × 10 10 Working example 16 Gd:0.75 - - - - 4,0 0,2 1,0 0,0 0,962 1280 420 3750 4,3 2,8 × 10 11 Working example 17 Gd:0.75 - - - - 4,0 1,0 1,0 0,0 0,962 1280 400 3520 3,3 9,2 × 10 10 Working example 18 Gd:0.75 - - - - 4,0 2,0 1,0 0,0 0,962 1230 360 3320 2,3 1,8 × 10 10 Working example 19 Gd:0.75 - - - - 4,0 5,0 1,0 0,0 0,962 1210 250 2830 1,3 1,5 × 10 10 Working example 20 Gd:0.75 - - - - 4,0 1,5 1,0 0,05 0,962 1270 300 3270 1,0 6,1 × 10 9 Working example 21 Gd:0.75 - - - - 4,0 1,5 1,0 0,2 0,962 1290 320 3300 0,8 8,1 × 10 9 Working example 22 Gd:0.75 - - - - 4,0 1,5 1,0 0,5 0,962 1270 320 3130 0,5 1,2 × 10 10 Working example 23 Gd:0.75 - - - - 4,0 1,5 1,0 1,0 0,962 1260 350 3030 1,3 2,4 × 10 10 Working example 24 Gd:0.75 - - - - 4,0 1,5 1,0 2,0 0,962 1240 350 2880 0,3 3,7 × 10 10 Working example 25 Gd:0.75 - - - - 4,0 1,5 1,0 5,0 0,962 1230 300 2620 1,0 3,8 × 10 10 Working example 26 Gd:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1280 270 3010 0,8 3,9 × 10 10 Working example 27 Gd:1.0 - - - - 4,0 1,5 1,0 0,5 0,962 1250 390 3410 0,5 1,1 × 10 10 Working example 28 Gd:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1230 410 3680 1,5 6,8 × 10 9 Working example 29 Eu:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1290 260 2950 0,2 1,0 × 10 9 Working example 30 Eu:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1260 330 3450 1,0 7,5 × 10 8 Working example 31 Tb:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1280 290 3100 0,2 6,0 × 10 10 Working example 32 Tb:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1260 420 3740 1,7 7,3 × 10 10 Working example 33 Dy:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1270 310 3200 0,3 8,3 × 10 10 Working example 34 Dy:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1250 440 3800 1,9 9,3 × 10 10 Working example 35 Y:0,25 - - - - 4,0 1,5 1,0 0,5 0,962 1270 320 3230 0,3 8,9 × 10 10 Working example 36 Y:2,5 - - - - 4,0 1,5 1,0 0,5 0,962 1240 450 3820 2,0 9,4 × 10 10 Working example 37 Ho:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1260 350 3110 0,5 9,5 × 10 10 Working example 38 Ho:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1240 470 3580 2,2 3,5 × 10 11 Working example 39 Er:0,25 - - - - 4,0 1,5 1,0 0,5 0,962 1260 340 3010 0,5 1,6 × 10 11 Working example 40 Er:2,5 - - - - 4,0 1,5 1,0 0,5 0,962 1240 450 3140 2,3 4,9 × 10 11 Working example 41 Yb:0.25 - - - - 4,0 1,5 1,0 0,5 0,962 1260 270 2320 0,2 3,3 × 10 11 Working example 42 Yb:2.5 - - - - 4,0 1,5 1,0 0,5 0,962 1240 230 2130 0,1 5,1 × 10 11 Working example 43 Gd:0.125 Dy:0.125 - - 4,0 1,5 1,0 0,5 0,962 1270 290 3140 0,5 7,7 × 10 10 Working example 44 Gd:1.25 Dy:1.25 - - 4,0 1,5 1,0 0,5 0,962 1250 420 3540 1,6 1,5 × 10 10 Working example 45 Eu:0.125 Ho:0.125 - - 4,0 1,5 1,0 0,5 0,962 1270 330 3040 0,4 5,5 × 10 9 Working example 46 Euro:1.25 Ho:1.25 - - 4,0 1,5 1,0 0,5 0,962 1240 420 3300 0,7 4,9 × 10 9 Working example 47 Gd:0.08 Tb:0.08 Y:0,09 4,0 1,5 1,0 0,5 0,962 1270 300 3180 0,3 7,1 × 10 10 Working example 48 Gd:0.8 Tb:0.8 Y:0,9 4,0 1,5 1,0 0,5 0,962 1230 430 3760 1,2 5,7 × 10 10 Working example 49 Gd:0.75 - - - - 4,0 1,5 0,2 0,5 0,962 1290 340 3400 3,0 8,5 × 10 10 Working example 50 Gd:0.75 - - - - 4,0 1,5 0,5 0,5 0,962 1280 330 3380 0,5 6,1 × 10 10 Working example 51 Gd:0.75 - - - - 4,0 1,5 2,0 0,5 0,962 1220 320 3300 5,5 8,2 × 10 9 Working example 52 Gd:0.75 - - - - 4,0 1,5 5,0 0,5 0,962 1200 330 3320 7,8 7,0 × 10 9 Working example 53 Gd:0.75 - - - - 1,0 1,5 1,0 0,5 0,990 1230 430 3640 1,8 1,3 × 10 11 Working example 54 Gd:0.75 - - - - 2,0 1,5 1,0 0,5 0,980 1240 360 3350 0,3 8,7 × 10 10 Working example 55 Gd:0.75 - - - - 6,0 1,5 1,0 0,5 0,943 1270 300 3050 1,0 3,8 × 10 9 Working example 56 Gd:0.75 - - - - 8,0 1,5 1,0 0,5 0,926 1270 350 2550 1,5 1,2 × 10 9 [Table 4] Average particle diameter (nm) ε (Δε / °C) Specific resistance at 150 °C (Ω cm) Working example6 280 3050 0,3 2,5 × 10 8 Working example7 320 3300 0,4 3,0 × 10 9 Working example8 330 3350 0,5 6,1 × 10 9 Working example9 340 3350 0,5 6,3 × 10 9 Working example10 370 3180 0,6 3 × 10 10 Working example11 360 3150 0,6 4,7 × 10 10 Working example12 250 2680 0,2 5,2 × 10 10 Working example13 300 3230 0,4 4,1 × 10 9 Working example14 330 3070 0,4 9,5 × 10 8 Working example15 310 3200 0,3 5,5 × 10 10 Working example16 420 3750 4,3 2,8 × 10 11 Working example17 400 3520 3,3 9,2 × 10 10 Working example18 360 3320 2,3 1,8 × 10 10 Working example19 250 2830 1,3 1,5 × 10 10 Working example20 300 3270 1,0 6,1 × 10 9 Working example21 320 3300 0,8 8,1 × 10 9 Working example22 320 3130 0,5 1,2 × 10 10 Working example23 350 3030 1,3 2,4 × 10 10 Working example24 350 2880 0,3 3,7 × 10 10 Working example25 300 2620 1,0 3,8 × 10 10 Working example26 270 3010 0,8 3,9 × 10 10 Working example27 390 3410 0,5 1,1 × 10 10 Working example28 410 3680 1,5 6,8 × 10 9 Working example29 260 2950 0,2 1,0 × 10 9 Working example30 330 3450 1,0 7,5 × 10 8 Working example31 290 3100 0,2 6,0 × 10 10 Working example32 420 3740 1,7 7,3 × 10 10 Working example33 310 3200 0,3 8,3 × 10 10 Working example34 440 3800 1,9 9,3 × 10 10 Working example35 320 3230 0,3 8,9 × 10 10 Working example36 450 3820 2,0 9,4 × 10 10 Working example37 350 3110 0,5 9,5 × 10 10 Working example38 470 3580 2,2 3,5 × 10 11 Working example39 340 3010 0,5 1,6 × 10 11 Working example40 450 3140 2,3 4,9 × 10 11 Working example41 270 2320 0,2 3,3 × 10 11 Working example42 230 2130 0,1 5,1 × 10 11 Working example43 290 3140 0,5 7,7 × 10 10 Working example44 420 3540 1,6 1,5 × 10 10 Working example45 330 3040 0,4 5,5 × 10 9 Working example46 420 3300 0,7 4,9 × 10 9 Working example47 300 3180 0,3 7,1 × 10 10 Working example48 430 3760 1,2 5,7 × 10 10 Working example49 340 3400 3,0 8,5 × 10 10 Working example50 330 3380 0,5 6,1 × 10 10 Working example51 320 3300 5,5 8,2 × 10 9 Working example52 330 3320 7,8 7,0 × 10 9 Working example53 430 3640 1,8 1,3 × 10 11 Working example54 360 3350 0,3 8,7 × 10 10 Working example55 300 3050 1,0 3,8 × 10 9 Working example56 350 2550 1,5 1,2 × 10 9

[0208] Working Examples 53 to 56 are working examples of dielectric ceramic compositions in which the amount of TiO2 added was changed to 1.0 mol, 2.0 mol, 6.0 mol, and 8.0 mol relative to 100 mol of BaTiO3. Together with Working Example 22, these were examples for determining the upper and lower limits for the amount of TiO2 in the range of 1.0 to 8.0 mol, while the amounts of the other additives, Gd2O3, MnCO3, SiO2, and MgO, were fixed.

[0209] It was found that in Working Examples 53 to 56 and Working Example 22, the value of Δε / °C was 2 or less, indicating that the dielectric constant was extremely stable with respect to the firing temperature. Furthermore, the average particle / grain diameter was also 500 nm or less, and the specific resistance at 150 °C was also 2.0 × 10 8Ω cm or more. Therefore, even with short-term firing due to a rapid temperature rise, higher mass production can be achieved and sufficient reliability can be maintained. It should be noted that in Working Example 56, the dielectric constant was 2550. In Working Examples 53 to 56 and Working Example 22, the dielectric constant tends to decrease as the addition amount increases, so it was found that adding more than 8.0 mol of TiO2 to 100 mol of BaTiO3 was not advantageous because it was apparent that the dielectric constant would further decrease. Therefore, an addition amount greater than this was determined to be outside the scope of the present invention.Tables 3 and 4 summarize the amounts of additives added in Working Examples 6 to 56, as well as the firing temperature, average particle diameter, ε, Δε / °C and resistivity at 150 °C.

[0210] In order to further evaluate or confirm whether the dielectric ceramic compositions of Working Examples 6 to 56 have the micro-features described in the embodiments, TEM-EDS, SEM-EDS and XRD measurements were conducted to determine whether the core-shell structure exists, whether Ba4Ti 11 O 26 whether the element ratio v of barium to titanium in the second crystal grain 42 is in the range of 0.16 ≦ v ≦ 0.70 and the element ratio w of manganese to titanium is in the range of 0.02 ≦ w ≦ 0.10. The results are summarized in Table 5. [Table 5] Is there a core-shell? Covering core Ba4Ti 11 O 26 found? Second crystal grain Rare earth elements / Ti element ratio Mn / Ti element ratio Rare earth elements / Ti element ratio Mn / Ti element ratio Ba / Ti element ratio Mn / Ti element ratio Working example 6 Yes Eu: 0,023 - - - - 0,019 Eu: 0,000 - - - - 0,000 Yes 0,47 0,03 Working example 7 Yes Tb: 0,027 - - - - 0,025 Tb: 0,000 - - - - 0,001 Yes 0,53 0,02 Working example 8 Yes Dy: 0,028 - - - - 0,026 Dy: 0,001 - - - - 0,001 Yes 0,49 0,04 Working example 9 Yes Y: 0,028 - - - - 0,025 Y: 0,001 - - - - 0,002 Yes 0,48 0,04 Working example 10 Yes Ho: 0,034 - - - - 0,028 Ho: 0,003 - - - - 0,003 Yes 0,54 0,05 Working example 11 Yes Er: 0,029 - - - - 0,026 Er: 0,001 - - - - 0,001 Yes 0,51 0,03 Working example 12 Yes Yb: 0,019 - - - - 0,017 Yb: 0,000 - - - - 0,000 Yes 0,27 0,02 Working example 13 Yes Gd: 0,012 Dy: 0,014 - - 0,023 Gd: 0,000 Dy: 0.000 - - 0,002 Yes 0,50 0,04 Working example 14 Yes Eu: 0,010 Ho: 0,018 - - 0,024 Eu: 0,000 Ho: 0.000 - - 0,003 Yes 0,39 0,06 Working example 15 Yes Gd: 0,008 Tb: 0,009 Y: 0,009 0,022 Gd: 0,000 Tb: 0.000 Y: 0,000 0,001 Yes 0,26 0,02 Working example 16 Yes Gd: 0,034 - - - - 0,00 Gd: 0,010 - - - - 0,000 Yes 0,46 0,02 Working example 17 Yes Gd: 0,025 - - - - 0,014 Gd: 0,000 - - - - 0,001 Yes 0,38 0,03 Working example 18 Yes Gd: 0,025 - - - - 0,026 Gd: 0,000 - - - - 0,002 Yes 0,41 0,03 Working example 19 Yes Gd: 0,022 - - - - 0,040 Gd: 0,000 - - - - 0,008 Yes 0,33 0,09 Working example 20 Yes Gd: 0,035 - - - - 0,028 Gd: 0,000 - - - - 0,000 Yes 0,48 0,03 Working example 21 Yes Gd: 0,032 - - - - 0,025 Gd: 0,001 - - - - 0,000 Yes 0,32 0,03 Working example 22 Yes Gd: 0,027 - - - - 0,023 Gd: 0,000 - - - - 0,000 Yes 0,44 0,03 Working example 23 Yes Gd: 0,028 - - - - 0,027 Gd: 0,000 - - - 0,000 Yes 0,48 0,03 Working example 24 Yes Gd: 0,028 - - - - 0,025 Gd: 0,000 - - - - 0,000 Yes 0,49 0,02 Working example 25 Yes Gd: 0,027 - - - - 0,025 Gd: 0,000 - - - - 0,000 Yes 0,29 0,04 Working example 26 Yes Gd: 0,011 - - - - 0,018 Gd: 0,002 - - - - 0,000 Yes 0,49 0,03 Working example 27 Yes Gd: 0,038 - - - - 0,022 Gd: 0,000 - - - - 0,000 Yes 0,45 0,03 Working example 28 Yes Gd: 0,045 - - - - 0,021 Gd: 0,004 - - - - 0,000 Yes 0,45 0,02 Working example 29 Yes Eu: 0,011 - - - - 0,018 Eu: 0,000 - - - - 0,000 Yes 0,47 0,03 Working example 30 Yes Eu: 0,041 - - - - 0,019 Eu: 0,002 - - - - 0,001 Yes 0,46 0,02 Working example 31 Yes Tb: 0,016 - - - - 0,021 Tb: 0,000 - - - - 0,000 Yes 0,53 0,02 Working example32 Yes Tb: 0,050 - - - - 0,027 Tb: 0,003 - - - - 0,001 Yes 0,52 0,01 Working example 33 Yes Dy: 0,015 - - - - 0,026 Dy: 0,000 - - - - 0,001 Yes 0,53 0,04 Working example 34 Yes Dy: 0,052 - - - - 0,027 Dy: 0,004 - - - - 0,003 Yes 0,55 0,04 Working example 35 Yes Y: 0,016 - - - - 0,023 Y: 0,000 - - - - 0,001 Yes 0,51 0,04 Working example 36 Yes Y: 0,053 - - - - 0,026 Y: 0,004 - - - - 0,003 Yes 0,48 0,04 Working example 37 Yes Ho: 0,020 - - - - 0,028 Ho: 0,000 - - - - 0,003 Yes 0,52 0,02 Working example 38 Yes Ho: 0,066 - - - - 0,032 Ho: 0,007 - - - - 0,005 Yes 0,55 0,03 Working example 39 Yes Er: 0,019 - - - - 0,024 Er: 0,000 - - - - 0,000 Yes 0,50 0,03 Working example 40 Yes Er: 0,054 - - - - 0,025 Er: 0,002 - - - - 0,002 Yes 0,49 0,03 Working example 41 Yes Yb: 0,022 - - - - 0,018 Yb: 0,000 - - - - 0,000 Yes 0,33 0,04 Working example 42 Yes Yb: 0,090 - - - - 0,015 Yb: 0,000 - - - - 0,000 Yes 0,27 0,02 Working example 43 Yes Gd: 0,007 Dy: 0,008 - - 0,020 Gd: 0,000 Dy: 0,000 - 0,000 0,000 Yes 0,49 0,03 Working example 44 Yes Gd: 0,024 Dy: 0,027 - - 0,023 Gd: 0,004 Dy: 0,000 - 0,000 0,003 Yes 0,52 0,03 Working example 45 Yes Eu: 0,004 Ho: 0,012 - - 0,019 Eu: 0,000 Ho: 0,000 - 0,000 0,001 Yes 0,38 0,03 Working example 46 Yes Eu: 0.026 Ho: 0,036 - - 0,022 Eu: 0.002 Ho: 0,003 - 0,000 0,003 Yes 0,35 0,04 Working example 47 Yes Gd: 0.003 Tb: 0,004 Y: 0,005 0,016 Gd: 0.000 Tb: 0,000 Y: 0,000 0,000 Yes 0,34 0,04 Working example 48 Yes Gd: 0.022 Tb: 0,027 Y: 0,028 0,020 Gd: 0.000 Tb: 0,001 Y: 0,002 0,001 Yes 0,30 0,02 Working example 49 Yes Gd: 0.035 - - - - 0,028 Gd: 0.012 - - - - 0,000 Yes 0,27 0,05 Working example 50 Yes Gd: 0.034 - - - - 0,028 Gd: 0.003 - - - - 0,000 Yes 0,46 0,05 Working example 51 Yes Gd: 0.031 - - - - 0,019 Gd: 0.000 - - - - 0,000 Yes 0,55 0,03 Working example 52 Yes Gd: 0.023 - - - - 0,020 Gd: 0.000 - - - - 0,000 Yes 0,56 0,03 Working example 53 Yes Gd: 0.026 - - - - 0,023 Gd: 0.000 - - - - 0,001 Yes 0,61 0,04 Working example 54 Yes Gd: 0.025 - - - - 0,031 Gd: 0.000 - - - - 0,002 Yes 0,49 0,05 Working example 55 Yes Gd: 0.025 - - - - 0,028 Gd: 0.001 - - - - 0,000 Yes 0,44 0,05 Working example 56 Yes Gd: 0.030 - - - - 0,027 Gd: 0.002 - - - - 0,002 Yes 0,42 0,03

[0211] In working examples 6 to 56 in Table 5, it was determined that a core-shell structure was present, Ba4Ti 11 O 26 was present in X-ray diffraction (XRD), and the element ratio v of barium to titanium and the element ratio w of manganese to titanium in the second crystal grains 42 were in the ranges of 0.16 ≦ v ≦ 0.70 and 0.02 ≦ w ≦ 0.10, respectively, so that the presence of the second crystal grains 42 was also evident. In Working Examples 6 to 56, as shown in Table 4, the value of Δε / °C was 12 or less, and the specific resistance at 150 °C was 2.0 × 10 8 Ω cm or more, the average particle / grain diameter was 500 nm or less, and the dielectric constant met ε > 2500 or more. Therefore, they were found to be suitable for use in a multilayer ceramic capacitor.

[0212] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. Description of reference symbols 10 Base 11 Dielectric layer 12 Inner electrode layer 13 Cover layer 14 Capacity range 15 End margin 16 margin 20a, 20b Outer electrode 41 First crystal grain 42 Second crystal grain 43 Third crystal grain 44 cavity 51 Ceramic green layer 52 Internal electrode structure 53 Dielectric structure 54 Cover layer 55 margin 100 multilayer ceramic capacitor QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] Acta Crystal. (1979), B35, 1590-1593

[0072] Japanese Industrial Standard" C5101-22:2021

[0116]

Claims

[1] A dielectric ceramic composition comprising: first crystal grains having a perovskite structure represented by the general formula ABO3, each first crystal grain having a core portion and a shell portion, the shell portion covering the core portion and containing a rare earth element and manganese; and second crystal grains whose main component is a barium titanate complex oxide in which an element ratio of barium to titanium is 0.70 or less. [2] The dielectric ceramic composition according to claim 1, wherein the rare earth element is at least one selected from gadolinium, europium, terbium, dysprosium, holmium, erbium and ytterbium. [3] The dielectric ceramic composition according to claim 2, wherein an element ratio of barium to titanium is 0.926 or more and 0.995 or less, an element ratio of the rare earth element to titanium is 0.005 or more and 0.05 or less, and an element ratio of manganese to titanium is 0.002 or more and 0.05 or less. [4] The dielectric ceramic composition according to claim 1, further comprising silicon having an element ratio of 0.002 or more and 0.05 or less with respect to titanium and magnesium having an element ratio of 0.00 or more and 0.05 or less with respect to titanium. [5] The dielectric ceramic composition according to claim 1, wherein the element concentrations of the rare earth element and the manganese in the shell portion are higher than the element concentrations of the rare earth element and the manganese in the core portion. [6] The dielectric ceramic composition according to claim 1, wherein the first crystal grains have a maximum grain size of 2 µm or less. [7] The dielectric ceramic composition according to claim 1, wherein the second crystal grain has an element ratio of barium to titanium of 0.16 or more. [8] The dielectric ceramic composition according to claim 1, wherein the second crystal grain comprises at least one selected from BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O 13 , Ba4Ti 11 O 26 , Ba4Ti 12 O 27 , Ba4Ti 13 O 30 or Ba6Ti 17 O 40 , is. [9] The dielectric ceramic composition according to claim 1, wherein the second crystal grain contains manganese and an element ratio of manganese to titanium in the second crystal grain is 0.02 or more and 0.10 or less. [10] The dielectric ceramic composition according to claim 1, wherein the second crystal grain contains manganese and an element ratio of manganese to titanium in the second crystal grain is 0.02 or more and 0.05 or less. [11] A dielectric ceramic composition comprising: first crystal grains having a perovskite structure represented by the general formula ABO3, each first crystal grain having a core portion and a shell portion, the shell portion covering the core portion and containing a rare earth element and manganese; and second crystal grains comprising a barium titanate complex oxide formed by Ba4Ti 11 O 26 and containing manganese, wherein an element ratio of barium to titanium is 0.02 or more and 0.10 or less. [12] The dielectric ceramic composition according to claim 11, wherein the rare earth element is at least one selected from gadolinium, europium, terbium, dysprosium, holmium, erbium and ytterbium. [13] The dielectric ceramic composition according to claim 12, wherein an element ratio of barium to titanium is 0.926 or more and 0.995 or less, an element ratio of the rare earth element to titanium is 0.005 or more and 0.05 or less, and an element ratio of manganese to titanium is 0.002 or more and 0.05 or less. [14] The dielectric ceramic composition according to claim 11, further comprising silicon having an element ratio of 0.002 or more and 0.05 or less with respect to titanium and magnesium having an element ratio of 0.00 or more and 0.05 or less with respect to titanium. [15] The dielectric ceramic composition according to claim 11, wherein element concentrations of the rare earth element and manganese in the shell portion are higher than element concentrations of the rare earth element and manganese in the core portion. [16] The dielectric ceramic composition according to claim 1, wherein the first crystal grains have a maximum grain size of 2 µm or less. [17] The dielectric ceramic composition according to claim 11, wherein the element ratio of manganese to titanium in the second crystal grains is 0.02 or more and 0.05 or less. [18] A multilayer ceramic electronic component comprising the dielectric ceramic composition according to claim 1. [19] Multilayer ceramic electronic component, comprising: a plurality of inner electrodes directed towards each other; Dielectric layers provided between the plurality of internal electrodes and comprising the dielectric ceramic composition according to claim 1; and outer electrodes, each electrically connected to the inner electrodes.

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