Dielectric ceramic composition and laminated ceramic electronic component

Abstract

The dielectric ceramic composition has a main phase containing barium titanate having a perovskite-type structure, first crystal particles satisfying 5.00 < = a < = 7.00 and 0.50 < = b < = 1.50, where a is the elemental ratio of titanium to barium content, and b is the elemental ratio of magnesium to barium content, and second crystal particles satisfying 5.00 < = a < = 7.00 and 0.50 < = b < = 1.50. The second crystal particles satisfy 1.50 < = c < = 3.50, 0.03 < = d < = 0.30, 0.03 < = e < = 0.30, and 0.03 < = f < = 0.40, where c is the element ratio of the titanium content to the barium content, d is the element ratio of the magnesium content to the barium content, e is the element ratio of the manganese content to the barium content, and f is the element ratio of the nickel content to the barium content.

Description

TECHNICAL FIELD

[0001] The present application relates to a dielectric ceramic composition and a multilayer ceramic electronic component. BACKGROUND

[0002] In a high-frequency communication system represented by a mobile phone and the like, a multilayer ceramic electronic component such as a multilayer ceramic capacitor (MLCC: Multi-Layer ceramic capacitor) is used.

[0003] PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: Japanese Patent Application Publication No. 2012-131669 Patent Document 2: Japanese Patent Application Publication No. 2016-153359 SUMMARY

[0004] PROBLEMS TO BE SOLVED BY THE INVENTION In a dielectric ceramic composition used in a dielectric layer of a multilayer ceramic electronic component, a sintered body of a core-sheath structure in which a core of barium titanate is surrounded by a sheath in which various additives are solid-solved is used. By adopting this structure, a large electrostatic capacity in the vicinity of the Curie temperature at which a ferroelectric phase of barium titanate present in the vicinity of 125°C changes to a paraelectric phase can be shifted to a lower temperature by the effect of various additives, and the electrostatic capacity can be designed to be higher in a temperature region of actual use in the vicinity of room temperature.

[0005] As an application example of barium titanate not having a core-sheath structure, a piezoelectric ceramic is disclosed in which, as a barium titanate composite oxide, at least one of Ba4Ti 12 O 27 or Ba6Ti 17 O 40 is contained, and manganese in an amount of 0.04 mass% or more and 0.20 mass% or less in terms of metal is contained with respect to barium titanate (for example, refer to Patent Document 1).

[0006] In addition, a piezoelectric ceramic is disclosed which contains a metal oxide represented by (Ba 1－x Ca x ) a (Ti 1－y Zr y )O3 (in the formula, 0.09 ≤ x ≤ 0.30, 0.025 ≤ y ≤ 0.085, 0.986 ≤ a ≤ 1.020.) and manganese in an amount of 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal with respect to 100 parts by weight of the metal oxide, and as a barium titanate composite oxide, contains BaTi2O5, BaTi4O9, BaTi5O 11 , BaTi6O13 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 at least one of the metal oxides (see Patent Literature 2, for example).

[0007] When the piezoelectric ceramics disclosed in Patent Literature 1 and Patent Literature 2 are applied to the dielectric ceramic composition used for the dielectric layer of a multilayer ceramic electronic component, as disclosed in Patent Literature 1 and Patent Literature 2, it is confirmed that the maximum particle diameter of the crystal particles is 2 μm or more, and in a multilayer ceramic electronic component in which the multilayer dielectric layer is 10 μm or less, there is a problem that the number of crystal grain boundaries is small and the insulation resistance is significantly deteriorated.

[0008] In recent years, the use of multilayer ceramic capacitors has also been expanded to electronic circuits related to human life such as vehicle-mounted electronic control devices, and thus it is necessary to ensure a high insulation resistance.

[0009] The present application has been made in view of the above technical problems, and aims to provide a dielectric ceramic composition and a multilayer ceramic electronic component capable of achieving a high insulation resistance.

[0010] Technical solution for solving the technical problem The dielectric ceramic composition according to the present application has a main phase, first crystal particles, and second crystal particles, the main phase contains barium titanate having a perovskite structure, the first crystal particles contain barium, titanium, and magnesium, when the element ratio of the content of titanium with respect to barium is set to a, and the element ratio of the content of magnesium with respect to barium is set to b, the first crystal particles satisfy 5.00 ≤ a ≤ 7.00 and 0.50 ≤ b ≤ 1.50, the second crystal particles contain barium, titanium, magnesium, manganese, and nickel, when the element ratio of the content of titanium with respect to barium is set to c, the element ratio of the content of magnesium with respect to barium is set to d, the element ratio of the content of manganese with respect to barium is set to e, and the element ratio of the content of nickel with respect to barium is set to f, the second crystal particles satisfy 1.50 ≤ c ≤ 3.50, 0.03 ≤ d ≤ 0.30, 0.03 ≤ e ≤ 0.30, and 0.03 ≤ f ≤ 0.40.

[0011] In the above dielectric ceramic composition, the above first crystalline particle can further contain manganese and nickel, and in the above first crystalline particle, when an elemental ratio of a content of manganese with respect to barium is g and an elemental ratio of a content of nickel with respect to barium is h, the first crystalline particle satisfies 0.10 ≤ g ≤ 4.00, 0.10 ≤ h ≤ 4.00.

[0012] The above dielectric ceramic composition can further contain a third crystalline particle, and the above third crystalline particle contains at least one of silica, enstatite, barium-magnesium silicate, or pseudobrookite.

[0013] In the above dielectric ceramic composition, the above first crystalline particle and the above second crystalline particle can be located at a grain boundary of the above main phase.

[0014] In the above dielectric ceramic composition, the above first crystalline particle and the above second crystalline particle can be located at a triple junction of the above main phase.

[0015] In the above dielectric ceramic composition, the above third crystalline particle can be located at a grain boundary of the above main phase.

[0016] In the above dielectric ceramic composition, the above third crystalline particle can be located at a triple junction of the above main phase.

[0017] In the above dielectric ceramic composition, the above main phase can have a core portion and a sheath portion covering the core portion.

[0018] In the above dielectric ceramic composition, a rare earth element can be contained in the above sheath portion.

[0019] In the above dielectric ceramic composition, an elemental ratio of barium with respect to titanium can be 0.940 or more and 0.980 or less, an elemental ratio of gadolinium with respect to titanium can be 0.005 or more and 0.05 or less, and an elemental ratio of magnesium with respect to titanium can be 0.002 or more and 0.02 or less.

[0020] Another dielectric ceramic composition according to the present application has a main phase and a first crystalline particle, the above main phase has a core portion containing barium titanate having a perovskite structure and a sheath portion covering the core portion, and the above first crystalline particle contains barium, titanium, and magnesium, and in the first crystalline particle, when an elemental ratio of a content of titanium with respect to barium is a and an elemental ratio of a content of magnesium with respect to barium is b, the first crystalline particle satisfies 5.00 ≤ a ≤ 7.00, 0.50 ≤ b ≤ 1.50.

[0021] In the above dielectric ceramic composition, the above first crystalline particle can further contain manganese and nickel, and in the above first crystalline particle, when an elemental ratio of a content of manganese with respect to a content of barium is g and an elemental ratio of a content of nickel with respect to a content of barium is h, the first crystalline particle satisfies 0.10 ≤ g ≤ 4.00, 0.10 ≤ h ≤ 4.00.

[0022] The laminated ceramic electronic component according to the present application includes: a plurality of dielectric layers including a dielectric ceramic composition; a plurality of internal electrodes facing each other across the plurality of dielectric layers; and an external electrode electrically connected to the plurality of internal electrodes.

[0023] Effects of the Invention According to the present application, it is possible to provide a dielectric ceramic composition and a laminated ceramic electronic component capable of achieving a high insulation resistance. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a view illustrating a dielectric ceramic composition according to a first embodiment.

[0025] Figure 2 is a view illustrating a unit cell.

[0026] Figure 3 is a partial cross-sectional perspective view of a laminated ceramic capacitor.

[0027] Figure 4 is a cross-sectional view of line A-A of Figure 3

[0028] Figure 5 is a cross-sectional view of line B-B of Figure 3

[0029] Figure 6 is a view illustrating a flow of a manufacturing method of a laminated ceramic capacitor.

[0030] Figure 7 (a) and (b) of are views illustrating an internal electrode forming step.

[0031] Figure 8 is a view illustrating a press bonding step.

[0032] Figure 9 is a view illustrating a side margin portion. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments will be described with reference to the drawings.

[0034] (First Embodiment) The dielectric ceramic composition according to the first embodiment is a ceramic polycrystal including crystalline particles having a perovskite structure represented by a general formula ABO3. These ceramic polycrystals are, for example,​​Figure 1 As exemplified, the main phase crystal particles 40 are contained, and the first crystal particles 41 are contained.

[0035] The main phase crystal particles 40 contain barium titanate having a perovskite structure. The first crystal particles 41 contain barium, titanium, and magnesium, and satisfy 5.00 ≤ a ≤ 7.00 and 0.50 ≤ b ≤ 1.50 when an element ratio of the content of titanium to the content of barium is set as a (hereinafter, also referred to as Ti / Ba element ratio a), and an element ratio of the content of magnesium to the content of barium is set as b (hereinafter, also referred to as Mg / Ti element ratio b).

[0036] For example, in a cross section of the dielectric ceramic composition, when the main phase crystal particles 40 and the first crystal particles 41 are observed in 400 or more fields of view, the area ratio of the main phase crystal particles 40 is 50.0% or more and 99.95% or less, and the area ratio of the first crystal particles 41 is 0.050% or more and 45.0% or less.

[0037] The crystal particles of barium titanate having a perovskite structure, which is a main component of the main phase crystal particles 40, have Figure 2 The unit cell exemplified. In the unit cell, there are A sites located at the vertices of the lattice, O sites located at the face centers of the lattice, and B sites located inside octahedrons having the O sites as the vertices, respectively. In the perovskite structure, the A sites are coordinated with alkali earth metals which can be divalent cations, such as barium (Ba), strontium (Sr), and calcium (Ca), and the B sites are coordinated with metal atoms which can be tetravalent cations, such as hafnium (Hf), zirconium (Zr), and titanium (Ti).

[0038] The perovskite structure also allows a composition formula deviating from the stoichiometric composition. That is, the ratio of the A site element and the B site element does not necessarily have to be 1 to 1, and can be generated with defects within a range in which the perovskite structure can be maintained. In addition, defects can also be generated with respect to oxygen. For example, when the composition formula is A α BO 3－β 0.98 ≤ α ≤ 1.01 and 0 ≤ β ≤ 0.20 can be allowed.

[0039] However, for example, due to generation of oxygen defects, the specific resistance decreases, or ion conductivity is exhibited, and thus, there can be cases in which the electrical life when used as a multilayer ceramic capacitor decreases, or the dielectric loss becomes large, or practical use cannot be applied. Therefore, the main phase crystal particles 40 having the perovskite structure can contain at least one of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba) as an alkali earth element, as necessary. Thereby, it is possible to increase the specific resistance, or to increase the electrical life, or to decrease the dielectric loss with respect to the static capacity.

[0040] In addition, the main phase crystal particle 40 can contain at least one of scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn) as a first transition element, as needed. Thereby, the electric resistivity can be increased, or the electric life can be increased, or the dielectric loss for the electrostatic capacity can be reduced.

[0041] In addition, the main phase crystal particle 40 can contain at least one of yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), and silver (Ag) as a second transition element, as needed. Thereby, the electric resistivity can be increased, or the electric life can be increased, or the dielectric loss for the electrostatic capacity can be reduced.

[0042] In addition, the main phase crystal particle 40 can contain at least one of 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) as a third transition element, as needed. Thereby, the electric resistivity can be increased, or the electric life can be increased, or the dielectric loss for the electrostatic capacity can be reduced.

[0043] By using at least one of the above-mentioned alkaline earth element, first transition metal element, second transition metal element, and third transition metal element as an additive, in a firing temperature region of 1000°C to 1400°C for obtaining the dielectric ceramic composition, at least one of the alkaline earth element, first transition metal element, second transition metal element, and third transition metal element is allowed to be solid-solved from the interface to the inside of the main phase crystalline particle 40, and the core portion 411 and the sheath portion 412 are generated in the main phase crystalline particle 40. For example, in the dielectric ceramic composition, it is preferable that the element ratio of the content of gadolinium with respect to the content of barium, that is, the Gd / Ti element ratio j, becomes 0.005 ≤ j ≤ 0.05, and that gadolinium in an amount of 0.25 mol or more and 2.5 mol or less, in terms of gadolinium oxide (Gd2O3), is added with respect to 100 mol of barium titanate. In addition to the addition of gadolinium oxide, it is preferable that the element ratio of the content of magnesium with respect to the content of barium, that is, the Mg / Ti element ratio k, becomes 0.002 ≤ k ≤ 0.05, and that magnesium in an amount of 0.2 mol or more and 2.0 mol or less, in terms of magnesium oxide (MgO), is added with respect to 100 mol of barium titanate. For example, when 0.005 ≤ j ≤ 0.05 and 0.002 ≤ k ≤ 0.02 are satisfied, the added gadolinium, manganese, and titanium react on the surface of the barium titanate crystalline particle, and can be generated as the sheath portion in the form of a complex perovskite compound which is considered to be Gd(Ti,Mg)O3. Thus, in the dielectric ceramic composition, the movement of oxygen defects to the inside of the grain boundary and the sheath portion can be suppressed, the reduction in the resistivity can be suppressed, and the electrical life can be improved.

[0044] Further, in the core-sheath structure, generally, as the firing temperature becomes higher, the various additives are more solid-solved in the crystalline particle composed of barium titanate, and there is a tendency that the sheath portion 412 becomes thicker and the particle diameter of the core portion 411 becomes smaller. In the sheath portion 412, for example, the acceptor element having a valence smaller than titanium, such as magnesium, is solid-solved as a B-site element, and the reduction of titanium at the time of reduction firing can be suppressed, and the insulation resistance can be improved. Therefore, as an example, in order to ensure a high insulation resistance of the multilayer ceramic capacitor, it is necessary to allow the acceptor element to be solid-solved in the sheath portion 412.

[0045] However, by allowing the acceptor element to be solid-solved in the sheath portion 412, oxygen defects are generated, and sometimes the electrical life is reduced and the reliability is decreased. Therefore, in order to balance a high insulation resistance and a high reliability, it is necessary to precisely control the amount of solid-solution of the acceptor element to the sheath portion 412.

[0046] The dielectric ceramic composition according to the present embodiment has, in addition to the main phase crystal particles 40 containing barium titanate having a perovskite structure, first crystal particles 41 satisfying 5.00 ≤ Ti / Ba element ratio a ≤ 7.00, 0.50 ≤ Mg / Ba element ratio b ≤ 1.50. By intentionally precipitating the first crystal particles 41 thus configured, high reliability can be achieved, and high insulation resistance can be achieved. By making the Ti / Ba element ratio a preferably 5.15 or more, more preferably 5.40 or more, high insulation resistance can be achieved. In addition, by making the Ti / Ba element ratio a preferably 6.85 or less, more preferably 6.60 or less, high insulation resistance can be achieved. By making the Mg / Ba element ratio b preferably 0.60 or more, more preferably 0.75 or more, high insulation resistance can be achieved. In addition, by making the Mg / Ba element ratio b preferably 1.40 or less, more preferably 1.25 or less, high insulation resistance can be achieved.

[0047] It is preferable that the first crystal particles 41 further contain manganese and nickel, and that, when the element ratio of the content of manganese with respect to barium is g (hereinafter, also referred to as Mn / Ba element ratio g), and the element ratio of the content of nickel with respect to barium is h (hereinafter, also referred to as Ni / Ba element ratio h), 0.10 ≤ g ≤ 4.00, 0.10 ≤ h ≤ 4.00 are satisfied. This is because the decrease in the resistivity of the dielectric ceramic composition can be suppressed. By making the Mn / Ba element ratio g more preferably 0.50 or more, further preferably 1.00 or more, high insulation resistance can be achieved. In addition, by making the Mn / Ba element ratio g more preferably 3.75 or less, further preferably 3.50 or less, high insulation resistance can be achieved. By making the Ni / Ba element ratio h preferably 0.50 or more, more preferably 1.00 or more, high insulation resistance can be achieved. In addition, by making the Ni / Ba element ratio h preferably 3.75 or less, more preferably 3.50 or less, high insulation resistance can be achieved.

[0048] In addition, the first crystal particles 41 can contain at least one of calcium, scandium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, and molybdenum. This is because the decrease in the resistivity of the dielectric ceramic composition can be suppressed.

[0049] The fact that the dielectric ceramic composition contains the first crystal particles 41 can be confirmed by the following steps.

[0050] First, the surface of the dielectric ceramic composition is exposed. The exposure method is not particularly limited and a method of cutting or grinding the element, or the like, can be employed. At this time, in order to sufficiently observe the internal ceramic structure, it is preferable to use a diamond polishing paste or the like, which is ultimately 2 micrometers or less, to obtain a smoothness that can be determined to be mirror-like. The above-mentioned method of cutting or grinding the element, or the like, is appropriate when observation is performed using an SEM. In addition, a thin piece having a thickness of 100 nm or less can also be obtained from the surface of the dielectric ceramic composition having a smoothness that can be determined to be mirror-like, using an ion beam or the like. The above-mentioned thin piece is appropriate when observation is performed using a STEM.

[0051] Next, the composition of the first crystal particles 41 is identified by an energy dispersive X-ray spectrometer (EDS) or a wavelength dispersive X-ray spectrometer (WDS) installed in a scanning electron microscope (SEM) or a scanning transmission electron microscope (STEM), an electron probe micro analyzer (EPMA), a laser irradiation type inductively coupled plasma mass spectrometer (LA-ICPMS), or the like.

[0052] For example, in the EDS measurement, the intensity of the K line of titanium and the K line of magnesium is determined with respect to the K line or L line of barium, simply speaking. In more detail, according to these intensities, a correction (ZAF correction) is performed considering the atomic number effect, the absorption effect, and the fluorescence excitation effect, the ratio of the elemental content of each element with respect to barium is calculated, and the ratio of each element is obtained.

[0053] When the EDS measurement is performed, particularly in the measurement using the Lα line of barium and the Kα line of titanium, the energy peaks are close, and it is sometimes difficult to sufficiently compare the elemental contents. Therefore, in the measurement, it is desirable to obtain the Lβ2 line and the LIII ab line of barium, which do not overlap the peaks, with sufficient intensity. Specifically, it is desirable that the intensity of this peak is 10,000 counts or more. At this time, the intensity of the characteristic X-ray of barium can be used to determine the elemental content, and therefore even if the Lα line of barium and the Kα line of titanium overlap, the intensity of the Kα line of titanium can be determined, and the elemental content can be evaluated with high precision.

[0054] When the crystalline particle is confirmed by the above method to have an element ratio a of Ti / Ba of 5.00 or greater and 7.00 or less and an element ratio b of Mg / Ba of 0.50 or greater and 1.50 or less, it is determined that the crystalline particle is the first crystalline particle 41. That is, the element ratio of titanium and magnesium with respect to barium is large compared to the main phase crystalline particle 40 composed of barium titanate existing in the surroundings, and it is determined that the barium titanate composite oxide is the first crystalline particle 41. At this time, when SEM is used for observation, in observation using a backscattered electron image (BSE image), the first crystalline particle 41 is characterized in that the brightness is relatively low, and is dark, compared to the main phase crystalline particle 40. In addition, when STEM is used for observation, in observation using a high-angle annular dark-field STEM image (HAADF-STEM image), the first crystalline particle 41 is characterized in that the brightness is relatively low, and is dark, compared to the main phase crystalline particle 40.

[0055] In addition, in the case of quantifying the manganese content and the nickel content contained in the first crystalline particle 41, the intensity of the K line of manganese and the K line of nickel with respect to the K line or the L line of barium is determined, simply speaking. In more detail, according to these intensities, the atomic number effect, the absorption effect, and the fluorescence excitation effect are corrected (ZAF correction), the ratio of the element content of each element with respect to barium is calculated, and the ratio of each element is obtained.

[0056] In addition, when the particle diameter of the first crystalline particle 41 is smaller than the spatial resolution in the EDS analysis using SEM, it is desirable to perform observation using a scanning transmission electron microscope (STEM), and to identify the composition of the first crystalline particle 41 using EDS.

[0057] As Figure 1As exemplified, the dielectric ceramic composition preferably contains, in addition to the main phase crystalline particles 40 and the first crystalline particles 41, the second crystalline particles 42. The second crystalline particles 42 contain barium, titanium, magnesium, manganese, and nickel, and satisfy 1.50 ≤ Ti / Ba elemental ratio c ≤ 3.50, 0.03 ≤ Mg / Ba elemental ratio d ≤ 0.30, 0.03 ≤ Mn / Ba elemental ratio e ≤ 0.30, and 0.03 ≤ Ni / Ba elemental ratio f ≤ 0.40, when the elemental ratio of the content of titanium to that of barium is set as c (hereinafter, also referred to as Ti / Ba elemental ratio c), the elemental ratio of the content of magnesium to that of barium is set as d (hereinafter, also referred to as Mg / Ba elemental ratio d), the elemental ratio of the content of manganese to that of barium is set as e (hereinafter, also referred to as Mn / Ba elemental ratio e), and the elemental ratio of the content of nickel to that of barium is set as f (hereinafter, also referred to as Ni / Ba elemental ratio f).

[0058] For example, in a cross section of the dielectric ceramic composition, when 400 or more of the field of view is confirmed in observation of the main phase crystalline particles 40, the first crystalline particles 41, and the second crystalline particles 42 in total, the area ratio of the main phase crystalline particles 40 is 50.0% or more and 99.95% or less, the area ratio of the first crystalline particles 41 is 0.050% or more and 45.0% or less, and the area ratio of the second crystalline particles 42 is 0.050% or more and 15.0% or less.

[0059] When an additive containing titanium as a main component is used as an additive, the second crystalline particles 42 are crystalline particles generated as a by-product. By intentionally precipitating the second crystalline particles 42, it is possible to obtain a high insulation resistance in a multilayer ceramic capacitor in which high reliability is pursued, while obtaining the main phase crystalline particles 40 and the first crystalline particles 41.

[0060] The Ti / Ba element ratio c is more preferably 1.70 or greater, and further preferably 1.90 or greater, whereby a high insulation resistance can be achieved. In addition, the Ti / Ba element ratio c is more preferably 2.70 or less, and further preferably 2.50 or less, whereby a high insulation resistance can be achieved. The Mg / Ba element ratio d is preferably 0.05 or greater, and more preferably 0.08 or greater, whereby a high insulation resistance can be achieved. In addition, the Mg / Ba element ratio d is preferably 0.25 or less, and more preferably 0.20 or less, whereby a high insulation resistance can be achieved. The Mn / Ba element ratio e is more preferably 0.05 or greater, and further preferably 0.08 or greater, whereby a high insulation resistance can be achieved. In addition, the Mn / Ba element ratio e is more preferably 0.25 or less, and further preferably 0.20 or less, whereby a high insulation resistance can be achieved. The Ni / Ba element ratio f is preferably 0.05 or greater, and more preferably 0.10 or greater, whereby a high insulation resistance can be achieved. In addition, the Ni / Ba element ratio f is preferably 0.35 or less, and more preferably 0.30 or less, whereby a high insulation resistance can be achieved.

[0061] The second crystalline particles 42 can further contain at least one of calcium, scandium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, and molybdenum. This is because the decrease in the resistivity of the dielectric ceramic composition can be suppressed.

[0062] The fact that the dielectric ceramic composition contains the second crystalline particles 42 can be confirmed by the following steps.

[0063] First, the surface of the dielectric ceramic composition is exposed. The exposure method is not particularly limited and a method such as cutting or grinding of the element can be used. At this time, in order to sufficiently observe the internal ceramic structure, it is preferable to use diamond grinding paste or the like having a final particle size of 2 micrometers or less, to obtain a smoothness that can be judged as a mirror surface. The above-mentioned method such as cutting or grinding of the element is appropriate when observation is performed using an SEM. In addition, a thin piece having a thickness of 100 nm or less can also be obtained from the surface of the dielectric ceramic composition having a smoothness that can be judged as a mirror surface, using an ion beam or the like. The above-mentioned thin piece is appropriate when observation is performed using a STEM.

[0064] Next, the composition of the second crystalline particles 42 is identified by EDS or WDS, EPMA, and LA-ICPMS, or the like, attached to an SEM or a STEM.

[0065] For example, in the EDS measurement, the intensity of the K line of titanium, the K line of magnesium, the K line of manganese, and the K line of nickel is determined with respect to the K line or L line of barium, simply speaking. In more detail, according to these intensities, the atomic number effect, the absorption effect, and the fluorescence excitation effect are corrected (ZAF correction), the ratio of the element content of each element with respect to barium is calculated, and the ratio of each element is calculated. In the case where the sample thickness is sufficiently thin, for example, 10 nm or less, the ratio coefficient (K factor) used in the Cliff-Lorimer method can be used for correction, and the ratio of each element is calculated. In addition, in addition to the correction used in the Cliff-Lorimer method, the absorption effect of the sample can be considered for correction, and the ratio of each element is calculated. The absorption effect of the sample can be corrected by finding the thickness and the density of the sample. The thickness of the sample can be found, for example, by obtaining a convergent-beam electron diffraction (CBED) pattern under double-beam excitation conditions, and analyzing the rocking curve obtained by observation with a diffraction disc. The particle for obtaining the CBED pattern can use the main phase crystal particle 40 or the like. The density of the sample can use the value of the density of barium titanate, that is, 6.02 g / cm 3 or the like.

[0066] In the EDS measurement, particularly in the measurement using the Lα line of barium and the Kα line of titanium, the energy peaks are close, and it is sometimes difficult to sufficiently compare the element content. Therefore, in the measurement, it is desirable to obtain the Lβ2 line and the LIII ab line of barium, which do not overlap the peaks, with sufficient intensity. Specifically, it is desirable that the intensity of this peak is 10,000 counts or more. At this time, the intensity of the characteristic X-ray of barium can be used to calculate the element content, and even if the Lα line of barium and the Kα line of titanium overlap, the intensity of the Kα line of titanium can be determined, and the element content can be evaluated with high accuracy.

[0067] When the crystalline particle is confirmed to have a Ti / Ba element ratio c of 1.50 ≤ c ≤ 3.50, a Mg / Ba element ratio d of 0.03 ≤ d ≤ 0.30, a Mn / Ba element ratio e of 0.03 ≤ e ≤ 0.30, and a Ni / Ba element ratio f of 0.03 ≤ f ≤ 0.40 by the above method, the crystalline particle is determined to be the second crystalline particle 42. That is, the second crystalline particle 42 is a barium titanate composite oxide that has a larger element ratio of titanium, magnesium, manganese, and nickel to barium than the main phase crystalline particle 40 composed of barium titanate existing in the surroundings, and has a smaller element ratio of titanium, magnesium, manganese, and nickel to barium than the first crystalline particle 41. At this time, in the case of using SEM for observation, in observation using a backscattered electron image (BSE image), the second crystalline particle 42 is characterized in that the brightness is relatively low and appears dark compared to the main phase crystalline particle 40. In the case of using STEM for observation, in observation using a high-angle annular dark-field STEM image (HAADF-STEM image), the second crystalline particle 42 is characterized in that the brightness is relatively low and appears dark compared to the main phase crystalline particle 40. In the case of quantifying the manganese content and the nickel content of the second crystalline particle 42, simply, the intensity of the K line of manganese and the K line of nickel to the K line or L line of barium is used for quantification. In more detail, the ratio of the element content of each element to barium is calculated as the ratio of each element by correcting the atomic number effect, the absorption effect, and the fluorescence excitation effect (ZAF correction) from these intensities. In the case of a sufficiently thin sample having a thickness of, for example, 10 nm or less, the ratio factor (K factor) used in the Cliff-Lorimer method can be used for correction as the ratio of each element. In addition to the correction used in the Cliff-Lorimer method, the absorption effect of the sample can be considered for correction as the ratio of each element. The absorption effect of the sample can be corrected by finding the thickness and the density of the sample. The thickness of the sample can be found, for example, by obtaining a convergent-beam electron diffraction (CBED) pattern under double-beam excitation conditions, and analyzing the rocking curve obtained by observation with a diffraction disc. The particle from which the CBED pattern is obtained can be the main phase crystalline particle 40 or the like. The density of the sample can be, for example, the density of barium titanate, which is 6.02 g / cm 3 and the like.

[0068] Further, when the particle size of the second crystalline particles 42 is smaller than the spatial resolution in the EDS analysis using the SEM, the composition of the second crystalline particles 42 is preferably identified by a scanning transmission electron microscope (STEM).

[0069] Further, the dielectric ceramic composition can contain, in addition to the main phase crystalline particles 40, the first crystalline particles 41, and the second crystalline particles 42, third crystalline particles 43, voids 44, and the like, which are different in composition or crystal structure from these. For example, when 400 or more fields of view are confirmed in the main phase crystalline particles 40, the first crystalline particles 41, the second crystalline particles 42, and the third crystalline particles 43 in the cross section of the dielectric ceramic composition, the area ratio of the third crystalline particles 43 is 0.050% or more and 15.0% or less.

[0070] The third crystalline particles 43 are crystalline particles of silica (Si02), enstatite (MgSi03), barium-magnesium silicate (BaMgSi04), silico-titanium barium stone (Ba2TiSi208), and the like. By containing the third crystalline particles, the dielectric ceramic composition can be sufficiently densified by firing at 1300°C or lower. Instead of the third crystalline particles 43, glass particles of silica (Si02), enstatite (MgSi03), barium-magnesium silicate (BaMgSi04), silico-titanium barium stone (Ba2TiSi208), and the like can be contained in the dielectric ceramic composition.

[0071] The dielectric ceramic composition can contain, in addition to the main phase crystalline particles 40, the first crystalline particles 41, the second crystalline particles 42, and the third crystalline particles 43, a secondary compound generated from an added substance such as magnesio-titanite (MgTi03), manganese-nickel oxide ((Mn, Ni)O), and red-titanium-manganese ore (MnTi03) or an electrode source.

[0072] As exemplified as above, the first crystalline particles 41 and the second crystalline particles 42 are preferably located at the grain boundaries of the main phase crystalline particles 40. This is because the decrease in the resistivity of the dielectric ceramic composition can be suppressed. Figure 1 The first crystalline particles 41 and the second crystalline particles 42 are preferably located at the grain boundary triple points of the main phase crystalline particles 40. This is because the decrease in the resistivity of the dielectric ceramic composition can be suppressed. Further, the grain boundary triple point refers to the boundary of 3 crystalline grain boundaries.

[0073] The third crystalline particles 43 are preferably located at the grain boundaries of the main phase crystalline particles 40. This is because the decrease in the relative dielectric constant of the dielectric ceramic composition can be suppressed.

[0074]

[0075] ​The third crystal particles 43 are preferably located at the triple junction of the grain boundaries of the main phase crystal particles 40. This is because it is possible to suppress a decrease in the relative dielectric constant of the dielectric ceramic composition.

[0076] The rare earth element is preferably contained in the sheath portion 412 of the main phase crystal particles 40. This is because it is possible to improve the lifetime of the dielectric ceramic composition.

[0077] The element ratio of the content of titanium with respect to the content of barium in the entirety of the main phase crystal particles 40, the first crystal particles 41, the second crystal particles 42, and the third crystal particles 43 is preferably greater than 0.940 and 0.980 or less. This is because it is possible to produce sufficient first crystal particles 41 and second crystal particles 42.

[0078] (Second Embodiment) In the second embodiment, a multilayer ceramic capacitor 100 using the dielectric ceramic composition according to the first embodiment will be described.

[0079] Figure 3 is a partial cross-sectional perspective view of the multilayer ceramic capacitor 100. Figure 4 is a cross-sectional view of A-A line of Figure 3 Figure 5 is a cross-sectional view of B-B line of Figure 3 As illustrated in Figures 3 to 5 , the multilayer ceramic capacitor 100 includes a laminate sheet 10 having a substantially rectangular parallelepiped shape and external electrodes 20a, 20b provided to arbitrary opposite two end surfaces of the laminate sheet 10. Further, of four surfaces of the laminate sheet 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, 20b extend to the upper surface, the lower surface, and the two side surfaces of the laminate sheet 10 in the stacking direction. Of these, the external electrodes 20a, 20b are spaced apart from each other by a gap.

[0080] The laminate sheet 10 has a structure in which a dielectric layer 11 containing a dielectric ceramic composition and an internal electrode layer 12 containing a base metal material are alternately stacked. The end edges of each internal electrode layer 12 are alternately exposed to the end surface on which the external electrode 20a is provided and the end surface on which the external electrode 20b is provided of the laminate sheet 10. Thus, the external electrode 20a and the external electrode 20b are alternately conducted in each internal electrode layer 12. As a result, the multilayer ceramic capacitor 100 has a structure in which a plurality of dielectric layers 11 are stacked with the internal electrode layer 12 interposed therebetween. In addition, in the laminate of the dielectric layer 11 and the internal electrode layer 12, the internal electrode layer 12 is disposed on the outermost layer in the stacking direction, and the upper surface and the lower surface of the laminate are covered with a cover layer 13. The cover layer 13 has a ceramic material as a main component. For example, the material of the cover layer 13 is the same as the main component of the ceramic material of the dielectric layer 11.

[0081] ​The dimensions of the multilayer ceramic capacitor 100 are, 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 long, 3.2 mm wide, and 2.5 mm high, but are not limited to these dimensions.

[0082] The internal electrode layer 12 is mainly composed of base metals such as Ni (nickel), Cu (copper), and Sn (tin). As the internal electrode layer 12, precious metals such as Pt (platinum), Pd (palladium), Ag (silver), and Au (gold), or alloys containing these precious metals, can be used.

[0083] like Figure 4 As illustrated, the regions of the inner electrode layer 12 connected to the external electrode 20a and the inner electrode layer 12 connected to the external electrode 20b, respectively, are the regions in the multilayer ceramic capacitor 100 that generate capacitance. Therefore, this region that generates capacitance is called the capacitance region 14. That is, the capacitance region 14 is the region in which adjacent inner electrode layers 12 connected to different external electrodes are opposite each other.

[0084] The region of the internal electrode layers 12 connected to the external electrode 20a that is not separated from each other by the internal electrode layers 12 connected to the external electrode 20b is called the end margin 15. Similarly, the region of the internal electrode layers 12 connected to the external electrode 20b that is not separated from each other by the internal electrode layers 12 connected to the external electrode 20a is also an end margin 15. In other words, the end margin 15 is the region of the internal electrode layers 12 connected to the same external electrode that is not separated from the internal electrode layers 12 connected to different external electrodes. The end margin 15 is a region that does not generate capacitance.

[0085] like Figure 5 As illustrated, in the laminate 10, the region extending from the two sides of the laminate 10 to the inner electrode layer 12 is referred to as the side edge 16. That is, the side edge 16 is a region that covers the ends of the plurality of inner electrode layers 12 stacked in the above-described laminate structure extending to the two side sides. The side edge 16 is also a region that does not generate capacitance.

[0086] In the multilayer ceramic capacitor 100 according to this embodiment, at least a portion of the dielectric layer 11 in the capacitance region 14 contains Figure 1 The illustrated main phase crystalline particles 40 and first crystalline particles 41. This enables high reliability and high insulation resistance.

[0087] Next, a manufacturing method of the multilayer ceramic capacitor 100 will be described. Figure 6 is a view illustrating a flow of the manufacturing method of the multilayer ceramic capacitor 100.

[0088] (Manufacturing process of raw material powder) First, a dielectric ceramic composition used for forming the dielectric layer 11 is prepared. The A-site element and the B-site element included in the dielectric layer 11 are generally included 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 belonging to tetragonal system near room temperature, and shows a high relative dielectric constant. This barium titanate can generally be synthesized by reacting a titanium raw material such as titanium dioxide and a barium raw material such as barium carbonate. As a method of synthesizing barium titanate as a main component of the dielectric layer 11, various methods are known, such as a solid phase method, a sol-gel method, a hydrothermal method, and the like. In the present embodiment, any one of these methods can be employed.

[0089] A prescribed additive is added to the barium titanate powder obtained by the above method. As an example, an additive in the range shown in the example of the dielectric ceramic composition according to the first embodiment is used. As needed, an oxide or a glass containing Zr (zirconium), V (vanadium), Cr (chromium), Co (cobalt), Ni (nickel), Li (lithium), B (boron), Na (sodium), K (potassium) can be used. In addition, as needed, an oxide of Sc (scandium), Y (yttrium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium) can be added as a rare earth element.

[0090] Further, in order to generate the first crystalline particles 41, it is preferable to add an additive having titanium as a main component in an amount of 0.002 mol or more and 0.06 mol or less in terms of titanium oxide (TiO2) and an additive having magnesium as a main component in an amount of 0.002 mol or more and 0.05 mol or less in terms of magnesium oxide (MgO) with respect to 1 mol of barium titanate. Thereby, the first crystalline particles 41 are generated. Further, as the additive having titanium as a main component, in addition to titanium oxide, titanium hydroxide (Ti(OH)4), titanium chloride (TiCl4), titanium carbide (TiC), titanium sulfide (TiS2), or the like can be used. In addition, as the additive having magnesium as a main component, in addition to magnesium oxide, magnesium hydroxide (MgOH), magnesium chloride (MgCl2), magnesium carbonate (MgCO3), magnesium sulfide (MgS), or the like can be used.

[0091] Furthermore, to generate the second crystalline particles 42, it is preferable to add, relative to 1 mole of barium titanate, an additive with titanium as the main component, in an amount of 0.002 mol to 0.08 mol (equivalent to titanium oxide (TiO2)), an additive with magnesium as the main component, in an amount of 0.002 mol to 0.05 mol (equivalent to magnesium oxide (MgO)), and an additive with manganese as the main component, in an amount of 0.002 mol to 0.05 mol (equivalent to manganese carbonate (MnCO3)). This generates the second crystalline particles 42. As the titanium-based additive, in addition to titanium oxide, titanium hydroxide (Ti(OH)4), titanium chloride (TiCl4), titanium carbide (TiC), titanium sulfide (TiS2), etc., can also be used. Similarly, as the magnesium-based additive, in addition to magnesium oxide, magnesium hydroxide (MgOH), magnesium chloride (MgCl2), magnesium carbonate (MgCO3), magnesium sulfide (MgS), etc., can also be used. In addition, as an additive with manganese as the main component, besides manganese carbonate, manganese monoxide (MnO), manganese trioxide (Mn3O4), manganese dioxide (MnO2), etc. can be used.

[0092] For example, a compound containing additives is wet-mixed with barium titanate powder, followed by drying and pulverization to prepare a ceramic material containing barium titanate powder and additives. For example, the ceramic material obtained as described above can be pulverized as needed to adjust the particle size, or combined with a grading process to achieve uniform particle size. Through the above steps, a dielectric ceramic composition is obtained.

[0093] (Coating process) Next, a binder such as 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 mixing is performed. Using the obtained slurry, ceramic green sheet 51 is coated onto a substrate, for example, by mold coating or blade coating, and then dried. The substrate is, for example, polyethylene terephthalate (PET) film. Figures illustrating the coating process are omitted.

[0094] (Internal electrode formation process) Next, as Figure 7 As illustrated in (a), a metallic conductive paste containing an organic binder for forming internal electrodes is printed onto the surface of the ceramic green sheet 51 by screen printing, gravure printing, or the like, thereby arranging internal electrode patterns 52 that alternately extend to a pair of external electrodes with different polarities. Ceramic particles are added to the metallic conductive paste as a common material. The main composition of the ceramic particles is not particularly limited, but it is preferably the same as the main ceramic component of the dielectric layer 11. For example, barium titanate with an average particle size of 50 nm or less can be uniformly dispersed.

[0095] Next, in the dielectric ceramic composition obtained through the raw material powder preparation process, binders such as ethyl cellulose and organic solvents such as terpineol are added, and the mixture is kneaded using a roller mill to obtain a dielectric pattern paste for the reverse patterning layer. For example... Figure 7 As illustrated in (a), on the ceramic green sheet 51, a dielectric pattern 53 is arranged by printing a dielectric pattern paste in the peripheral area where the internal electrode pattern 52 is not printed, thus filling the height difference with the internal electrode pattern 52. The ceramic green sheet 51 with the internal electrode pattern 52 and the dielectric pattern 53 printed on it is referred to as a stacked unit.

[0096] Then, as Figure 7 As illustrated in (b), the stacked units are stacked in such a way that the inner electrode layer 12 and the dielectric layer 11 are different from each other, and in such a way that the two end faces of the inner electrode layer 12 alternately expose their end edges in the longitudinal direction of the dielectric layer 11 and alternately extend to a pair of external electrodes 20a, 20b with different polarities. For example, the number of layers of the inner electrode pattern 52 is set to 100 to 1000.

[0097] (Crimping process) like Figure 8 As illustrated, a predetermined number (e.g., 2 to 10 layers) of cover sheets 54 are stacked on top of and below the laminated body containing the stacked units, and then heat-pressed together. The ceramic material for the cover sheets 54 can be, for example, the dielectric ceramic composition described above. Then, it is cut to a predetermined sheet size (e.g., 1.0 mm × 0.5 mm).

[0098] (Firing process) The ceramic laminate obtained in this process is subjected to debinding treatment in N2 atmosphere and atmospheric atmosphere, and then coated with metal paste to form the base layer of the external electrodes 20a and 20b by dip coating. The coating is then subjected to an oxygen partial pressure of 10. -12 ~10 -9 The ceramic capacitor 100 is fired at 1100–1300°C for 10 minutes to 2 hours in a reducing atmosphere of atm. Furthermore, rapid heating is performed during the firing process. For example, the heating rate during the firing process is 6000°C / h. This shortens the actual firing time and results in a higher production rate.

[0099] (Annealing process) Subsequently, at an oxygen partial pressure of 10 -12 ~10 -9 Annealing at 900–1150°C for 30 minutes to 2 hours in a reducing atmosphere of atm, followed by slow cooling. The cooling rate is, for example, 200°C / h. Through this operation, at least a portion of the dielectric layer 11 in the capacitance region 14 can be formed. Figure 1The main phase crystalline particles 40 are exemplified, and the first crystalline particles 41 are formed.

[0100] (Re-oxidation treatment step) Thereafter, re-oxidation treatment is performed at 600°C to 1000°C in an N2 atmosphere.

[0101] (Plating treatment step) Thereafter, on the base layer of the external electrodes 20a, 20b, metal coating of Cu, Ni, Sn, or the like is performed by plating treatment. Through the above steps, the multilayer ceramic capacitor 100 is completed.

[0102] With the manufacturing method according to the present embodiment, the first crystalline particles 41 can be formed in at least a part of the dielectric layer 11 of the capacity region 14. Figure 1 The main phase crystalline particles 40 are exemplified, and the first crystalline particles 41 are formed. Thereby, high reliability can be achieved, and high insulation resistance can be achieved.

[0103] The direct current resistivity p (Ω·cm) of the multilayer ceramic capacitor is measured by the following method.

[0104] First, the multilayer ceramic capacitor 100 that has undergone the firing step, the annealing step, the re-oxidation treatment step, and the plating treatment step is subjected to measurement of the direct current I (nA). Next, for the multilayer ceramic capacitor 100, the direct current resistivity p (Ω·cm) is measured. Figure 4 and Figure 5 The A-A line section and the B-B line section exemplified are made to expose the capacity region 14 by a method such as cutting or grinding, and a state in which smoothness that can be judged as a mirror surface is obtained using diamond polishing paste or the like with a final particle size of 2 micrometers or less, and the effective area of the internal electrode layer 12 is calculated. The effective area S is calculated from S = L x W x (N - 1) according to the length L (X-axis direction) of the internal electrode layer 12 in the capacity region 14 and the number of layers N, and Figure 4 the width W (Y-axis direction) of the internal electrode layer 12 in the capacity region 14. Figure 5 In addition, the respective thicknesses of the dielectric layer 11 at this time are also measured, and the average thickness t is calculated. At this time, the direct current resistivity p (Ω·cm) is calculated from p = V / IxS / t when the direct current voltage at the time of measurement is V (V).

[0105] Further, in each of the above embodiments, the multilayer ceramic capacitor is described as an example of the multilayer ceramic electronic component, but is not limited thereto. For example, other multilayer ceramic electronic components such as a varistor, a thermistor, or the like can be used.

[0106] Example (Example 1) A barium titanate powder having an average particle diameter of 150 nm was prepared, and to 100 mol of the barium titanate powder, 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 obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.980.

[0107] The dielectric ceramic composition was mixed with ethanol, toluene, and a PVB (polyvinyl butyral) resin to prepare a dielectric paste. The paste was formed into a ceramic green sheet by a die coater, and was dried. A metal conductive paste containing a main component metal of the internal electrode layer 12, a co-material, a binder (ethyl cellulose), a solvent, and other additives as needed was prepared by a planetary ball mill, and was screen-printed on the ceramic green sheet. Eleven pieces of the layer stack on which the metal conductive paste was printed were stacked on the ceramic green sheet, and cover sheets were stacked on the upper and lower surfaces of the layer stack. Then, a laminate was obtained by hot-pressing, and was cut into a prescribed shape. The obtained laminate was debindered in a N2 atmosphere, and a metal conductive paste containing a metal filler having Ni as a main component, a co-material, a binder, a solvent, and the like for a base layer was applied to each of the two end surfaces and the side surfaces of the laminate, and was dried. Then, the metal conductive paste for the base layer and the laminate were simultaneously fired at 1300°C in a reducing atmosphere to obtain a sintered body. The temperature increase rate was set to 6000°C / h. The sintered body had a shape and size of 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height. Then, annealing treatment was performed at 900 to 1150°C for one hour. Then, reoxidation treatment was performed at 950°C. Then, plating treatment was performed to form a plated Cu layer, a plated Ni layer, and a plated Sn layer on the surface of the base layer, and a multilayer ceramic capacitor 100 was obtained. The average thickness of the dielectric layer 11 was 2.0 μm.

[0108] (Example 2) In Example 2, to 100 mol of a barium titanate powder, 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 obtain a dielectric ceramic composition. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1250°C. The annealing time was set to one hour. The other conditions were the same as in Example 1.

[0109] (Example 3) In Example 3, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1250°C. The annealing time was set to 0.5 hours. The other conditions were the same as in Example 1.

[0110] (Example 4) In Example 4, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1250°C. The annealing time was set to 2 hours. The other conditions were the same as in Example 1.

[0111] (Example 5) In Example 5, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO26.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.943. The firing temperature was set to 1200°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0112] (Example 6) In Example 6, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.2 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1280°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0113] (Example 7) In Example 7, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 1.0 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1250°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0114] (Example 8) In Example 8, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 2.0 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1250°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0115] (Example 9) In Example 9, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO20.2 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1300°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0116] (Example 10) In Example 10, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO20.5 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1300°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0117] (Example 11) In Example 11, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO22.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1200°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0118] (Example 12) In Example 12, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO35.0 mol, adding SiO20.5 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1300°C. The annealing time was set to 0.5 hour. The other conditions were the same as in Example 1.

[0119] (Example 13) In Example 13, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO30.2 mol, adding SiO20.5 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1300°C. The annealing time was set to 2 hours. The other conditions were the same as in Example 1.

[0120] (Comparative Example 1) In Comparative Example 1, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO21.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.990. The firing temperature was set to 1320°C. The annealing time was set to 2 hours. The other conditions were the same as in Example 1.

[0121] (Comparative Example 2) In Comparative Example 2, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO28.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.5 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.926. The firing temperature was set to 1160°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0122] (Comparative Example 3) In Comparative Example 3, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 0.05 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1300°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0123] (Comparative Example 4) In Comparative Example 4, a dielectric ceramic composition was obtained by adding Gd2O30.75 mol, adding TiO24.0 mol, adding MnCO31.5 mol, adding SiO21.0 mol, and adding MgO 5.0 mol, with respect to 100 mol of barium titanate powder. The Ba / Ti element ratio was 0.962. The firing temperature was set to 1200°C. The annealing time was set to 1 hour. The other conditions were the same as in Example 1.

[0124] (Comparative Example 5) In Comparative Example 5, 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 with respect 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 set to 1250°C. The annealing time was set to 0 hours. That is, no annealing treatment was performed. The other conditions were the same as in Example 1.

[0125] The conditions of Examples 1 to 13 and Comparative Examples 1 to 5 are shown in Table 1.

[0126] [Table 1] With respect to each of the multilayer ceramic capacitors of Examples 1 to 13 and Comparative Examples 1 to 5, the direct current I at 150°C when 60V was applied for 30 seconds was measured using an insulation impedance meter, and the resistivity p was calculated. In addition, the first crystalline particles were confirmed to satisfy 5.00 ≤ Ti / Ba element ratio a ≤ 7.00 and 0.50 ≤ Mg / Ba element ratio b ≤ 1.50 in the dielectric layer. In addition, the Ti / Ba element ratio a, the Mg / Ba element ratio b, the Mn / Ba element ratio g, and the Ni / Ba element ratio h in the first crystalline particles were measured. In addition, the second crystalline particles having a large element ratio of titanium, magnesium, manganese, and nickel with respect to barium compared to the main phase crystalline particles composed of barium titanate existing in the surroundings and a small element ratio of titanium, magnesium, manganese, and nickel with respect to barium compared to the first crystalline particles were confirmed. In addition, the Ti / Ba element ratio c, the Mg / Ba element ratio d, the Mn / Ba element ratio e, and the Ni / Ba element ratio f in the second crystalline particles were measured. The results are shown in Table 2.

[0127] In Example 1, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.32, the Mg / Ba element ratio b was 1.00, the Mn / Ba element ratio g was 2.28, and the Ni / Ba element ratio h was 1.76. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 1.62, the Mg / Ba element ratio d was 0.14, the Mn / Ba element ratio e was 0.14, and the Ni / Ba element ratio f was 0.18. The resistivity p was 2.9 x 10 11 Ω·cm.

[0128] In Example 2, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.60, the Mg / Ba element ratio b was 1.11, the Mn / Ba element ratio g was 2.85, and the Ni / Ba element ratio h was 2.02. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.16, the Mg / Ba element ratio d was 0.13, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.20. The resistivity p was 9.5 x 10 11 Ω·cm.

[0129] In Example 3, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.66, the Mg / Ba element ratio b was 1.14, the Mn / Ba element ratio g was 3.42, and the Ni / Ba element ratio h was 1.01. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.31, the Mg / Ba element ratio d was 0.12, the Mn / Ba element ratio e was 0.03, and the Ni / Ba element ratio f was 0.37. The resistivity p was 2.1 x 10 11 Ω·cm.

[0130] In Example 4, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.71, the Mg / Ba element ratio b was 1.10, the Mn / Ba element ratio g was 1.71, and the Ni / Ba element ratio h was 3.03. In addition, the second crystalline particles were not confirmed. The resistivity p was 4.1 x 10 10 Ω·cm.

[0131] In Example 5, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 6.85, the Mg / Ba element ratio b was 1.08, the Mn / Ba element ratio g was 0.15, and the Ni / Ba element ratio h was 2.10. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 3.23, the Mg / Ba element ratio d was 0.11, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.19. The resistivity p was 1.5 x 10 11 Ω·cm.

[0132] In Example 6, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.82, the Mg / Ba element ratio b was 0.54, the Mn / Ba element ratio g was 2.74, and the Ni / Ba element ratio h was 2.04. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.20, the Mg / Ba element ratio d was 0.03, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.16. The resistivity p was 2.0 x 10 11 Ω·cm.

[0133] In Example 7, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.71, the Mg / Ba element ratio b was 1.21, the Mn / Ba element ratio g was 2.72, and the Ni / Ba element ratio h was 2.02. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.09, the Mg / Ba element ratio d was 0.16, the Mn / Ba element ratio e was 0.11, and the Ni / Ba element ratio f was 0.24. The resistivity p was 6.6 x 10 11 Ω·cm.

[0134] In Example 8, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.60, the Mg / Ba element ratio b was 1.44, the Mn / Ba element ratio g was 2.91, and the Ni / Ba element ratio h was 1.94. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.03, the Mg / Ba element ratio d was 0.29, the Mn / Ba element ratio e was 0.11, and the Ni / Ba element ratio f was 0.24. The resistivity p was 2.9 x 10 11 Ω·cm.

[0135] In Example 9, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.15, the Mg / Ba element ratio b was 0.78, the Mn / Ba element ratio g was 2.88, and the Ni / Ba element ratio h was 1.96. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.18, the Mg / Ba element ratio d was 0.12, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.22. The resistivity p was 5.1 x 10 11 Ω·cm.

[0136] In Example 10, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.26, the Mg / Ba element ratio b was 0.92, the Mn / Ba element ratio g was 2.89, and the Ni / Ba element ratio h was 2.00. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.24, the Mg / Ba element ratio d was 0.12, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.22. The resistivity p was 4.9 x 10 11 Ω·cm.

[0137] In Example 11, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 6.72, the Mg / Ba element ratio b was 1.33, the Mn / Ba element ratio g was 1.91, and the Ni / Ba element ratio h was 1.98. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.22, the Mg / Ba element ratio d was 0.12, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.22. The resistivity p was 3.9 x 10 11 Ω·cm.

[0138] In Example 12, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.38, the Mg / Ba element ratio b was 0.92, the Mn / Ba element ratio g was 4.13, and the Ni / Ba element ratio h was 0.07. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.76, the Mg / Ba element ratio d was 0.12, the Mn / Ba element ratio e was 0.02, and the Ni / Ba element ratio f was 0.32. The resistivity p was 2.3 x 10 10 Ω·cm.

[0139] In Example 13, the first crystalline particles were confirmed. In the first crystalline particles, the Ti / Ba element ratio a was 5.43, the Mg / Ba element ratio b was 0.97, the Mn / Ba element ratio g was 0.05, and the Ni / Ba element ratio h was 4.12. In addition, the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 1.83, the Mg / Ba element ratio d was 0.13, the Mn / Ba element ratio e was 0.32, and the Ni / Ba element ratio f was 0.05. The resistivity p was 2.4 x 10 10 Ω·cm.

[0140] In Comparative Example 1, neither the first crystalline particles nor the second crystalline particles were confirmed. The resistivity p was 4.4 x 10 9 Ω·cm.

[0141] In Comparative Example 2, the first crystalline particles were not confirmed, but the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 3.05, the Mg / Ba element ratio d was 0.11, the Mn / Ba element ratio e was 0.11, and the Ni / Ba element ratio f was 0.18. The specific resistance p was 1.3 x 10 9 Ω·cm.

[0142] In Comparative Example 3, the first crystalline particles were not confirmed, but the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.37, the Mg / Ba element ratio d was 0.00, the Mn / Ba element ratio e was 0.35, and the Ni / Ba element ratio f was 0.38. The specific resistance p was 5.8 x 10 9 Ω·cm.

[0143] In Comparative Example 4, the first crystalline particles were not confirmed, but the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.09, the Mg / Ba element ratio d was 0.31, the Mn / Ba element ratio e was 0.11, and the Ni / Ba element ratio f was 0.22. The specific resistance p was 1.8 x 10 9 Ω·cm.

[0144] In Comparative Example 5, the first crystalline particles were not confirmed, but the second crystalline particles were confirmed. In the second crystalline particles, the Ti / Ba element ratio c was 2.16, the Mg / Ba element ratio d was 0.13, the Mn / Ba element ratio e was 0.12, and the Ni / Ba element ratio f was 0.20. The specific resistance p was 8.0 x 10 9 Ω·cm.

[0145] The results of Examples 1 to 13 and Comparative Examples 1 to 5 are shown in Table 2.

[0146] [Table 2] As shown in Table 2, in Examples 1 to 13, the specific resistance p (Ω-cm) was confirmed to be 10 10 orders of magnitude or more, and a high insulation resistance was achieved. This can be considered to be due to the generation of the first crystalline particles in addition to the main phase crystalline particles.

[0147] The resistivity of Examples 1 to 3, 5 to 11 is higher than that of Examples 4, 12, 13. This can be considered to be due to the fact that, in Examples 1 to 3, 5 to 11, in addition to the first crystalline particles, second crystalline particles were confirmed, and the second crystalline particles satisfied 1.50 ≤ Ti / Ba element ratio c ≤ 3.50, 0.03 ≤ Mg / Ba element ratio d ≤ 0.30, 0.03 ≤ Mn / Ba element ratio e ≤ 0.30, 0.03 ≤ Ni / Ba element ratio f ≤ 0.40.

[0148] Further, for Examples 1 to 13, the main phase crystalline particles contained in the dielectric layer were evaluated for composition by EDS, and it was confirmed that the main phase crystalline particles had a core-sheath structure.

[0149] The above describes the embodiments of the present application in detail, but the present application is not limited to the specific embodiments, and various modifications and changes can be made within the gist of the present application recited in the scope of the claims.

[0150] Explanation of symbols 10 layer 11 dielectric layer 12 internal electrode layer 13 cover layer 14 capacity region 15 end edge 16 side edge 20a, 20b external electrode 40 main phase crystalline particle 41 first crystalline particle 42 second crystalline particle 43 third crystalline particle 44 void 51 ceramic green sheet 52 internal electrode pattern 53 dielectric pattern 54 cover sheet 55 side edge portion 100 layer-built ceramic capacitor

Claims

1. A dielectric ceramic composition, characterized in that: It has a main phase, first crystalline grains, and second crystalline grains. The main phase comprises barium titanate with a perovskite-type structure. The first crystalline particle contains barium, titanium, and magnesium. When the elemental ratio of titanium to barium is set as 'a' and the elemental ratio of magnesium to barium is set as 'b', the first crystalline particle satisfies 5.00 ≤ a ≤ 7.00 and 0.50 ≤ b ≤ 1.

50. The second crystalline particle contains barium, titanium, magnesium, manganese and nickel. When the elemental ratio of titanium to barium is set as c, the elemental ratio of magnesium to barium is set as d, the elemental ratio of manganese to barium is set as e, and the elemental ratio of nickel to barium is set as f, the second crystalline particle satisfies 1.50≤c≤3.50, 0.03≤d≤0.30, 0.03≤e≤0.30, and 0.03≤f≤0.

40.

2. The dielectric ceramic composition according to claim 1, characterized in that: The first crystalline particle also contains manganese and nickel. In the first crystalline particle, when the elemental ratio of manganese to barium is set as g and the elemental ratio of nickel to barium is set as h, the first crystalline particle satisfies 0.10≤g≤4.00 and 0.10≤h≤4.

00.

3. The dielectric ceramic composition according to claim 1, characterized in that: It also contains a third crystalline particle, which comprises at least one of silica, enstatite, barium magnesium silicate, or barium silicate.

4. The dielectric ceramic composition according to claim 1, characterized in that: The first crystalline grain and the second crystalline grain are located at the grain boundaries of the main phase.

5. The dielectric ceramic composition according to claim 1, characterized in that: The first crystalline grain and the second crystalline grain are located at the grain boundary trifles of the main phase.

6. The dielectric ceramic composition according to claim 3, characterized in that: The third crystalline grain is located at the grain boundary of the main phase.

7. The dielectric ceramic composition according to claim 3, characterized in that: The third crystalline grain is located at the grain boundary trifle of the main phase.

8. The dielectric ceramic composition according to claim 1, characterized in that: The main phase has a core and a sheath covering the core.

9. The dielectric ceramic composition according to claim 8, characterized in that: The sheath contains rare earth elements.

10. The dielectric ceramic composition according to claim 1, characterized in that: The elemental ratio of barium to titanium is 0.940 to 0.980, the elemental ratio of gadolinium to titanium is 0.005 to 0.05, and the elemental ratio of magnesium to titanium is 0.002 to 0.

02.

11. A dielectric ceramic composition, characterized in that: It has a main phase and first crystalline grains. The main phase comprises: a core containing barium titanate with a perovskite structure and a sheath covering the core. The first crystalline particle contains barium, titanium, and magnesium. When the elemental ratio of titanium to barium is set as a and the elemental ratio of magnesium to barium is set as b, the first crystalline particle satisfies 5.00≤a≤7.00 and 0.50≤b≤1.

50.

12. The dielectric ceramic composition according to claim 11, characterized in that: The first crystalline particle also contains manganese and nickel. In the first crystalline particle, when the elemental ratio of manganese to barium is set as g and the elemental ratio of nickel to barium is set as h, the first crystalline particle satisfies 0.10≤g≤4.00 and 0.10≤h≤4.

00.

13. A laminated ceramic electronic component, characterized in that, include: A plurality of dielectric layers comprising the dielectric ceramic composition of claim 1; Multiple internal electrodes facing each other across the multiple dielectric layers; and External electrodes that are electrically connected to the plurality of internal electrodes.

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