Multilayer ceramic capacitor

Abstract

A multilayer ceramic capacitor 1 comprises: an element body 10 including a plurality of dielectric ceramic layers 20 and a plurality of internal electrode layers 30 laminated in the thickness direction T; and external electrodes 11, 12 provided on the surface of the element body 10 and electrically connected to the internal electrode layers 30. The element body 10 includes an effective part 10B in which the plurality of internal electrode layers 30 overlap each other in the thickness direction T with the dielectric ceramic layers 20 interposed therebetween. The dielectric ceramic layers 20 include crystal particles 40 composed of a perovskite composite oxide. The perovskite composite oxide includes a rare earth element (Re) and barium (Ba), and further includes at least one of calcium (Ca) and strontium (Sr) and at least one of titanium (Ti) and zirconium (Zr). In the dielectric ceramic layer 20 located in the effective part 10B, when a region surrounded by grain boundaries 41 of the crystal particles 40 is defined as a grain 42, the rare earth element (Re) exists in a state of a solid solution in at least a central region of the grain 42. In the peak intensities measured by an X-ray diffraction method with respect to the dielectric ceramic layer 20 located in the effective part 10B, when Ic is defined as the peak intensity on the (400) plane corresponding to a cubic perovskite composite oxide and It is defined as the peak intensity on the (004) plane corresponding to a tetragonal perovskite composite oxide, 1<Ic / It<2 is satisfied.

Description

Multilayer ceramic capacitor

[0001] This invention relates to a multilayer ceramic capacitor.

[0002] Patent Document 1 describes a multilayer ceramic capacitor in which a dielectric layer composed of barium titanate crystal particles with a calcium concentration of 0.2 atomic percent or less and barium calcium titanate crystal particles with a calcium concentration of 0.4 atomic percent or more, and an internal electrode layer are alternately stacked, wherein the barium titanate crystal particles and the barium calcium titanate crystal particles contain magnesium, two rare earth elements (one of yttrium and holmium and one of terbium and dysprosium), and vanadium, and the magnesium and yttrium on the surface side of the barium titanate crystal particles A multilayer ceramic capacitor is disclosed, characterized in that the ratio of the content of magnesium contained in the central part of the barium titanate crystal grain and the content of one of the rare earth elements (yttrium and holmium) to the content of one of the rare earth elements (yttrium and holmium) is greater than the ratio of the content of magnesium contained in the central part of the barium titanate calcium crystal grain and the content of one of the rare earth elements (yttrium and holmium) to the content of magnesium on the surface side of the barium titanate calcium crystal grain and the content of one of the rare earth elements (yttrium and holmium) to).

[0003] Patent Document 2 describes a method in which barium titanate is the main component, and vanadium is added to 100 moles of barium that constitutes the barium titanate. ２ O ５ In terms of conversion, 0.05 to 0.3 moles of magnesium in MgO equivalent, 0 to 0.1 moles of manganese in MnO equivalent, and one rare earth element (RE) selected from yttrium, dysprosium, holmium, and erbium. ２ O ３A multilayer ceramic capacitor is disclosed that uses a dielectric ceramic that contains 0.5 to 1.5 moles of barium titanate in conversion terms, further containing calcium, and whose crystalline particles are mainly composed of the above-mentioned barium titanate with a calcium concentration of 0.4 atomic percent or more, characterized in that, in the X-ray diffraction chart of the dielectric ceramic, the diffraction intensity of the (004) plane showing tetragonal barium titanate is greater than the diffraction intensity of the (400) plane showing cubic barium titanate.

[0004] Japanese Patent Publication No. 2008-135638 Japanese Patent Publication No. 2009-51717

[0005] According to Patent Document 1, barium titanate crystal particles have a high cubic crystal structure in the core-shell structure, and by coexisting these highly cubic barium titanate crystal particles with barium calcium titanate crystal particles, it is possible to obtain a multilayer ceramic capacitor that has high insulation resistance even after firing and exhibits little decrease in insulation resistance with time changes during high-temperature load testing.

[0006] However, in multilayer ceramic capacitors in which the dielectric layer (hereinafter also referred to as the dielectric ceramic layer) is composed of crystalline particles based on a core-shell structure, as described in Patent Document 1, localized electric field concentration may occur when a high-intensity electric field is applied, potentially leading to a decrease in insulation resistance over time during high-temperature load testing. Therefore, from the viewpoint of obtaining multilayer ceramic capacitors with a long high-temperature load life, there is still room for improvement.

[0007] Furthermore, according to Patent Document 2, by making the diffraction intensity of the (004) plane, which represents tetragonal barium titanate, greater than the diffraction intensity of the (400) plane, which represents cubic barium titanate, in the X-ray diffraction chart of the dielectric ceramic, it is possible to achieve a high dielectric constant and a temperature dependence of the relative permittivity that satisfies the EIA standard X7R characteristics. Furthermore, according to Patent Document 1, it is possible to obtain a dielectric ceramic that can be made in which high insulation resistance can be obtained even when the applied voltage is low, and in which the decrease in insulation resistance when the voltage is increased is small (low voltage dependence of insulation resistance).

[0008] However, in multilayer ceramic capacitors, such as those described in Patent Document 2, where the dielectric layer is composed of crystal grains with a higher proportion of tetragonal grains than cubic grains, the proportion of the ferroelectric layer increases, which may result in a relatively small effective capacitance (capacitance when voltage is applied). Therefore, there is room for improvement from the perspective of obtaining a multilayer ceramic capacitor with a large effective capacitance (capacitance when voltage is applied).

[0009] This invention was made to solve the above problems and aims to provide a multilayer ceramic capacitor with a long high-temperature load life and a large effective capacitance.

[0010] The multilayer ceramic capacitor of the present invention comprises a base body including a plurality of dielectric ceramic layers and a plurality of internal electrode layers stacked in the thickness direction, and an external electrode provided on the surface of the base body and electrically connected to the internal electrode layer, wherein the base body includes an effective portion in which the plurality of internal electrode layers overlap each other in the thickness direction via the dielectric ceramic layer, the dielectric ceramic layer includes crystalline particles composed of a perovskite-type composite oxide, and the perovskite-type composite oxide includes a rare earth element (Re) and barium (Ba), as well as at least one of calcium (Ca) and strontium (Sr) The present invention further comprises titanium (Ti) and zirconium (Zr), wherein, in the dielectric ceramic layer of the effective portion, when the region surrounded by the grain boundaries of the crystal grains is defined as a grain, the rare earth element (Re) is solid-dissolved in at least the central region of the grain, and when the peak intensity measured by X-ray diffraction for the dielectric ceramic layer of the effective portion is defined as follows: Ic is the peak intensity on the (400) plane corresponding to the cubic perovskite-type composite oxide, and It is the peak intensity on the (004) plane corresponding to the tetragonal perovskite-type composite oxide, the present invention is characterized in that 1 < Ic / It < 2 is satisfied.

[0011] According to the present invention, it is possible to provide a multilayer ceramic capacitor with a long high-temperature load life and a large effective capacitance.

[0012] Figure 1 is a schematic perspective view showing an example of a multilayer ceramic capacitor of the present invention. Figure 2 is an example of an LT cross-sectional view along the length direction L and thickness direction T on line II-II of the multilayer ceramic capacitor shown in Figure 1. Figure 3 is an example of a WT cross-sectional view along the width direction W and thickness direction T on line III-III of the multilayer ceramic capacitor shown in Figure 1. Figure 4 is an example of an LW cross-sectional view along the length direction L and width direction W on line IV-IV of the multilayer ceramic capacitor shown in Figure 1. Figure 5A is an example of an enlarged cross-sectional view of the dielectric ceramic layer sandwiched between internal electrode layers in the effective portion. Figure 5B is a schematic diagram showing an example of crystal grains constituting the dielectric ceramic layer in the region enclosed by the dashed line in Figure 5A.

[0013] Hereinafter, the multilayer ceramic capacitor of the present invention will be described. Note that the present invention is not limited to the following configuration, and may be appropriately modified without departing from the gist of the present invention. Also, a combination of a plurality of the individual preferred configurations described below is also within the scope of the present invention.

[0014] The drawings shown below are schematic diagrams, and their dimensions, scales of aspect ratios, etc. may differ from those of actual products.

[0015] In this specification, unless otherwise specified, terms indicating the relationship between elements (e.g., "parallel", "perpendicular", etc.) and terms indicating the shape of elements do not only mean a strictly literal aspect, but also mean a substantially equivalent range, for example, a range including a difference of about several percent.

[0016] [Multilayer Ceramic Capacitor] The multilayer ceramic capacitor of the present invention includes a body including a plurality of dielectric ceramic layers and a plurality of internal electrode layers laminated in the thickness direction, and external electrodes provided on the surface of the body and electrically connected to the internal electrode layers. The body includes an effective portion in which the plurality of internal electrode layers overlap each other in the thickness direction via the dielectric ceramic layers. The dielectric ceramic layer includes crystal grains composed of a perovskite-type composite oxide. The perovskite-type composite oxide contains a rare earth element (Re) and barium (Ba), and further contains at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr). When a region surrounded by grain boundaries of the crystal grains is defined as a grain in the dielectric ceramic layer of the effective portion, the rare earth element (Re) is dissolved in at least the central region of the grain. Among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, when the peak intensity of the (400) plane corresponding to the cubic perovskite-type composite oxide is defined as Ic, and the peak intensity of the (004) plane corresponding to the tetragonal perovskite-type composite oxide is defined as It, it satisfies 1 < Ic / It < 2.

[0017] In the multilayer ceramic capacitor of the present invention, the perovskite-type composite oxide constituting the crystal particles of the dielectric ceramic layer contains a rare earth element (Re). As a result, various characteristics such as the reliability of the multilayer ceramic capacitor of the present invention and the temperature characteristics of the dielectric constant are improved.

[0018] On the other hand, the perovskite-type composite oxide constituting the crystal particles of the dielectric ceramic layer may contain many oxygen vacancies generated in the firing process. These oxygen vacancies tend to reduce the insulation resistance when accompanied by electron compensation, and also tend to move under an electric field, resulting in a time-dependent decrease in the insulation resistance.

[0019] In contrast, in the multilayer ceramic capacitor of the present invention, in the dielectric ceramic layer of the effective portion, when the region surrounded by the grain boundaries of the crystal particles is regarded as a grain, the rare earth element (Re) is dissolved in at least the central region of the grain. In the multilayer ceramic capacitor of the present invention in which the rare earth element (Re) is dissolved in at least the central region of the grain, for example, compared with a multilayer ceramic capacitor having a so-called core-shell structure in which the rare earth element (Re) is not dissolved in the central region (core portion) of the grain but is dissolved in the peripheral region (shell portion) of the central region, in the crystal particles of the dielectric ceramic layer of the effective portion, the dissolved rare earth element (Re) is more likely to act as a donor or acceptor, so that it is more likely to prevent the movement of oxygen vacancies or suppress the generation of conduction electrons. Therefore, in the multilayer ceramic capacitor of the present invention, the deterioration of the insulation resistance is reduced and the high-temperature load life is prolonged.

[0020] Furthermore, in the multilayer ceramic capacitor of the present invention, when the peak intensity measured by X-ray diffraction for the dielectric ceramic layer of the effective portion is denoted as Ic for the (400) plane corresponding to the cubic perovskite composite oxide and as It for the (004) plane corresponding to the tetragonal perovskite composite oxide, the condition 1 < Ic / It < 2 is satisfied. As a result, in the multilayer ceramic capacitor of the present invention, the proportion of cubic perovskite composite oxide is somewhat higher than that of tetragonal perovskite composite oxide in the crystal grains of the dielectric ceramic layer of the effective portion, thus increasing the effective capacitance of the multilayer ceramic capacitor.

[0021] Based on the above, the multilayer ceramic capacitor of the present invention makes it possible to realize a multilayer ceramic capacitor with a long high-temperature load life and a large effective capacitance.

[0022] The following describes a specific example of the multilayer ceramic capacitor of the present invention.

[0023] Figure 1 is a schematic perspective view showing an example of the multilayer ceramic capacitor of the present invention.

[0024] The multilayer ceramic capacitor 1 shown in Figure 1 comprises a base body 10, an external electrode 11, and an external electrode 12.

[0025] In the base body 10, the length direction, width direction, and thickness direction are defined by the double-headed arrows L, W, and T, respectively. The length direction L, the width direction W, and the thickness direction T are perpendicular to each other.

[0026] The base body 10 is, for example, a rectangular parallelepiped. In this case, the base body 10 has a first main surface 10a and a second main surface 10b that are opposite to the thickness direction T, a first side surface 10c and a second side surface 10d that are opposite to the width direction W, and a first end surface 10e and a second end surface 10f that are opposite to the length direction L.

[0027] At least one of the corners and edges of the base body 10 may be rounded. Here, the corners of the base body 10 are the parts where the three faces of the base body 10 intersect. The edges of the base body 10 are the parts where the two faces of the base body 10 intersect.

[0028] The external electrode 11 is provided on the surface of the base body 10. In the example shown in Figure 1, the external electrode 11 is provided on the first end face 10e of the base body 10. As shown in Figure 1, the external electrode 11 may wrap around from the first end face 10e of the base body 10 to a part of the first main surface 10a, the second main surface 10b, the first side surface 10c, and the second side surface 10d.

[0029] The external electrode 12 is provided on the surface of the base body 10. In the example shown in Figure 1, the external electrode 12 is provided on the second end face 10f of the base body 10. As shown in Figure 1, the external electrode 12 may wrap around from the second end face 10f of the base body 10 to a part of the first main surface 10a, the second main surface 10b, the first side surface 10c, and the second side surface 10d.

[0030] The dimensions of the multilayer ceramic capacitor 1 are not particularly limited. For example, in the multilayer ceramic capacitor 1, the length L dimension is 0.4 mm or more and 5.7 mm or less, the width W dimension is 0.2 mm or more and 5.0 mm or less, and the thickness T dimension is 0.125 mm or more and 5.0 mm or less.

[0031] Figure 2 is an example of a cross-sectional view (LT) along the length direction L and thickness direction T on line II-II of the multilayer ceramic capacitor shown in Figure 1. Figure 3 is an example of a cross-sectional view (WT) along the width direction W and thickness direction T on line III-III of the multilayer ceramic capacitor shown in Figure 1. Figure 4 is an example of a cross-sectional view (LW) along the length direction L and width direction W on line IV-IV of the multilayer ceramic capacitor shown in Figure 1.

[0032] The base body 10 includes a plurality of dielectric ceramic layers 20 and a plurality of internal electrode layers 30 stacked in the thickness direction T.

[0033] The base body 10 includes an inner layer portion 10A in which a plurality of dielectric ceramic layers 20 and a plurality of internal electrode layers 30 are alternately stacked in the thickness direction T. The inner electrode layer 30 closest to the first main surface 10a is located at the end of the inner layer portion 10A on the first main surface 10a side, and the inner electrode layer 30 closest to the second main surface 10b is located at the end of the inner layer portion 10A on the second main surface 10b side.

[0034] The base body 10 includes an effective portion 10B in which a plurality of internal electrode layers 30 overlap each other in the thickness direction T via a dielectric ceramic layer 20. In the base body 10, the effective portion 10B is included in the inner layer portion 10A. At the end of the effective portion 10B on the first main surface 10a side, the internal electrode layer 30 closest to the first main surface 10a is located, and at the end of the effective portion 10B on the second main surface 10b side, the internal electrode layer 30 closest to the second main surface 10b is located.

[0035] The base body 10 may include an outer layer 10C outside the inner layer 10A, where only dielectric ceramic layers 20 are laminated in the thickness direction T. The outer layer 10C is located on both main surface sides of the base body 10 relative to the inner layer 10A (the first main surface 10a side and the second main surface 10b side), and includes dielectric ceramic layers 20 located between each main surface and the internal electrode layer 30 closest to that main surface (between the first main surface 10a and the internal electrode layer 30 closest to the first main surface 10a, and between the second main surface 10b and the internal electrode layer 30 closest to the second main surface 10b). In other words, in the base body 10, the region sandwiched in the thickness direction T by both outer layer portions 10C is the inner layer 10A.

[0036] The internal electrode layer 30 includes a first internal electrode layer 31 and a second internal electrode layer 32 that are alternately arranged in the thickness direction T.

[0037] The first internal electrode layer 31 extends to the first end face 10e of the base body 10, where it is electrically connected to the external electrode 11.

[0038] The second internal electrode layer 32 extends to the second end face 10f of the base body 10, where it is electrically connected to the external electrode 12.

[0039] The first internal electrode layer 31 and the second internal electrode layer 32, which face each other with the dielectric ceramic layer 20 in between, are not electrically connected. Therefore, when a voltage is applied between the first internal electrode layer 31 and the second internal electrode layer 32 via the external electrodes 11 and 12, charge accumulates in the effective portion 10B. The charge accumulated in the effective portion 10B generates capacitance, thereby enabling the device to function as a capacitive element.

[0040] Figure 5A is an example of an enlarged cross-sectional view of the dielectric ceramic layer sandwiched between internal electrode layers in the effective portion. Figure 5B is a schematic diagram showing an example of the crystal grains constituting the dielectric ceramic layer in the region enclosed by the dashed line in Figure 5A.

[0041] The dielectric ceramic layer 20 is made of ceramic. Specifically, the dielectric ceramic layer 20 contains crystalline particles 40 (see Figures 5A and 5B) made of a perovskite-type composite oxide.

[0042] The dielectric ceramic layer 20 preferably contains crystalline grains 40 composed of a perovskite-type composite oxide as its main component. In this specification, the main component means the component that accounts for the largest mass percentage in the ceramic. The mass percentage of the main component is not particularly limited as long as it is less than 100% by mass, and may be, for example, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more.

[0043] The perovskite-type composite oxide constituting the crystal grain 40 has the general formula ABO ３ This is represented as (A represents the A-site element, B represents the B-site element, and O represents the oxygen element). In the perovskite-type composite oxide constituting the crystal grain 40, the molar ratio of the A-site element to the B-site element is not strictly limited to 1:1, and deviations in the molar ratio of the A-site element to the B-site element are permitted as long as the perovskite-type crystal structure is maintained.

[0044] In the following, the crystal grains 40 composed of the above-mentioned perovskite-type composite oxide will also be referred to as main crystal grains.

[0045] The perovskite-type composite oxide constituting the crystal grains 40 contains rare earth elements (Re) and barium (Ba), and further contains at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr).

[0046] The perovskite-type composite oxide constituting the crystal grains 40 contains rare earth elements (Re). This improves various properties of the multilayer ceramic capacitor 1, such as reliability and the temperature characteristics of the dielectric constant.

[0047] On the other hand, the perovskite-type composite oxide constituting the crystalline grains 40 of the dielectric ceramic layer 20 may contain many oxygen vacancies generated during the firing process. These oxygen vacancies tend to reduce the insulation resistance when accompanied by electronic compensation, and they also tend to move under an electric field, leading to a decrease in insulation resistance over time.

[0048] In contrast, in the multilayer ceramic capacitor 1, when the region surrounded by grain boundaries 41 of the crystal grains 40 in the dielectric ceramic layer 20 of the effective portion 10B is defined as a grain 42 (see Figure 5B), the rare earth element (Re) is solid-dissolved in at least the central region of the grain 42. In the multilayer ceramic capacitor 1 in which the rare earth element (Re) is solid-dissolved in at least the central region of the grain 42 in this way, compared to a multilayer ceramic capacitor having a so-called core-shell structure in which the rare earth element (Re) is solid-dissolved in the peripheral region (shell) of the central region (core) of the grain 42 and not in the central region (core), the solid-dissolved rare earth element (Re) in the crystal grains 40 of the dielectric ceramic layer 20 of the effective portion 10B is more likely to act as a donor or acceptor, thus making it easier to hinder the movement of oxygen vacancies or to suppress the generation of conduction electrons. Therefore, in the multilayer ceramic capacitor 1, the degradation of insulation resistance is reduced, and the high-temperature load life is extended.

[0049] The rare earth element (Re) only needs to be dissolved in at least the central region of the grain 42. Specifically, the rare earth element (Re) may be dissolved only in the central region of the grain 42, or it may be dissolved in the central region as well as in regions other than the central region of the grain 42. In particular, it is preferable that the rare earth element (Re) is dissolved throughout the entire grain 42, and more preferably that it is uniformly dissolved throughout the entire grain 42.

[0050] For the multilayer ceramic capacitor 1, the distribution of rare earth elements (Re) in the grains 42 of the dielectric ceramic layer 20 of the effective portion 10B is confirmed by the following method. First, the multilayer ceramic capacitor 1 is embedded in a thermosetting resin and then polished to expose the WT cross section (see Figure 3) along the width direction W and thickness direction T of the effective portion 10B. Next, a sample containing the dielectric ceramic layer 20 is cut out from the exposed WT cross section of the effective portion 10B using the FIB (Focused Ion Beam) lift-out method. Subsequently, the position of grains 42 in the dielectric ceramic layer 20 is confirmed using a field emission transmission electron microscope (FE-TEM) on the cut-out sample. Then, elemental analysis of the grains 42 is performed using an energy dispersive X-ray spectrometer (EDX) attached to a scanning transmission electron microscope (STEM), and a mapping image showing the elemental distribution within the grains 42 is obtained. The distribution of rare earth elements (Re) in the grains 42 is then confirmed from the obtained mapping image. In the multilayer ceramic capacitor 1, the mapping image described above confirms that rare earth elements (Re) are distributed in at least the central region of the grain 42, and this state is considered to be that the rare earth elements (Re) are solid-dissolved in at least the central region of the grain 42.

[0051] Rare earth elements (Re) are a collective term for the elements that make up the group in the periodic table consisting of scandium (Sc) with atomic number 21, yttrium (Y) with atomic number 39, and lanthanum (La) with atomic number 57 to lutetium (Lu) with atomic number 71.

[0052] The perovskite-type composite oxide constituting the crystal grain 40 may contain one type of rare earth element (Re), or it may contain a combination of multiple types of rare earth elements (Re).

[0053] If the perovskite-type composite oxide constituting the crystal grain 40 contains a combination of multiple types of rare earth elements (Re), it is sufficient that at least one type of rare earth element (Re) is solid-dissolved in at least the central region of the grain 42.

[0054] Rare earth elements (Re) may be contained only in the main crystal grains, or they may be contained in the main crystal grains as well as in grain boundaries or triple points, etc.

[0055] When rare earth elements (Re) are present in the main crystal grains, they may occupy the A site, the B site, or both sites of the perovskite-type composite oxide.

[0056] The rare earth element (Re) is not particularly limited in type, but it preferably contains at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), and ytterbium (Yb), and more preferably contains dysprosium (Dy).

[0057] Dysprosium (Dy) is an element located near the middle of the lanthanide group in the periodic table, and its ionic radius is also of an intermediate size. Therefore, dysprosium (Dy) can be solid-solved in both the A and B sites of perovskite-type composite oxides. Thus, when a rare earth element (Re) contains dysprosium (Dy), and the dysprosium (Dy) is solid-solved in both the A and B sites of the perovskite-type composite oxide, it leads to a further improvement in the reliability of the multilayer ceramic capacitor 1.

[0058] The perovskite-type composite oxide constituting the crystal grains 40 may contain only dysprosium (Dy) as the rare earth element (Re), or it may contain dysprosium (Dy) in addition to other rare earth elements (Re).

[0059] The perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba) in addition to rare earth elements (Re), and further contains at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr).

[0060] The aforementioned barium (Ba), calcium (Ca), strontium (Sr), titanium (Ti), and zirconium (Zr) may be contained only in the main crystal grains, or they may be contained in the main crystal grains as well as in grain boundaries or triple points, etc.

[0061] When barium (Ba) is included in the main crystal grains, it is preferable that it occupies the A site of the perovskite-type composite oxide.

[0062] When at least one of calcium (Ca) and strontium (Sr) is included in the main crystal grains, it is preferable that it occupies the A site of the perovskite-type composite oxide.

[0063] It is preferable that at least one of titanium (Ti) and zirconium (Zr), when included in the main crystal grains, occupies the B site of the perovskite-type composite oxide.

[0064] The perovskite-type composite oxide constituting the crystal grains 40 contains at least one of titanium (Ti) and zirconium (Zr), and it is preferable that it contains titanium (Ti). In this case, the perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba) and titanium (Ti), so barium titanate (BaTiO) ３ It could also be said that it contains compounds of the ) type.

[0065] Barium titanate (BaTiO) ３ ) is a ferroelectric material exhibiting a high dielectric constant. Therefore, the dielectric ceramic layer 20 has barium titanate (BaTiO) as a perovskite-type composite oxide constituting the crystal grains 40. ３ The inclusion of a compound of the ) type increases the dielectric constant of the dielectric ceramic layer 20, which in turn makes it possible to increase the capacitance of the multilayer ceramic capacitor 1.

[0066] Barium titanate (BaTiO ３ ) has a large temperature dependence of dielectric constant near the Curie temperature Tc. Therefore, the dielectric ceramic layer 20 contains a barium titanate (BaTiO ３ )-based compound as the perovskite-type composite oxide constituting the crystal particles 40, and a rare earth element (Re) is dissolved in at least the central region of the grain 42, which is a region surrounded by the grain boundaries 41 of the crystal particles 40, so that the temperature change of the dielectric constant of the dielectric ceramic layer 20 becomes flatter in a wide temperature range including the Curie temperature Tc.

[0067] Barium titanate (BaTiO ３ )-based compounds are not particularly limited as long as they are perovskite-type composite oxides mainly containing barium (Ba) and titanium (Ti). For example, the barium titanate (BaTiO ３ )-based compound may be a compound in which at least a part of barium (Ba) and titanium (Ti) contained in barium titanate (BaTiO ３ ) is substituted with other elements. For example, in barium titanate (BaTiO ３ ), a part of barium (Ba) may be substituted with an alkaline earth metal element such as calcium (Ca) or strontium (Sr), and a part of titanium (Ti) may be substituted with a transition metal element such as zirconium (Zr).

[0068] The perovskite-type composite oxide constituting the crystal particles 40 may further contain at least one metal element (M) selected from the group consisting of vanadium (V), molybdenum (Mo), niobium (Nb), and tantalum (Ta). In this case, it is preferable that the perovskite-type composite oxide constituting the crystal particles 40 contains vanadium (V). These metal elements (M) may be contained only in the main crystal particles, or may be contained in grain boundaries or triple points in addition to the main crystal particles.

[0069] The perovskite-type composite oxide constituting the crystal grains 40 may further contain elements other than the rare earth elements (Re), barium (Ba), calcium (Ca), strontium (Sr), titanium (Ti), zirconium (Zr), and metallic elements (M) mentioned above. Examples of other elements include manganese (Mn), magnesium (Mg), silicon (Si), and aluminum (Al). These other elements may be contained only in the main crystal grains, or they may be contained in the main crystal grains as well as in grain boundaries or triple points, etc.

[0070] In the multilayer ceramic capacitor 1, when the peak intensities measured by X-ray diffraction (XRD) for the dielectric ceramic layer 20 of the effective portion 10B are denoted as Ic, the peak intensity on the (400) plane corresponding to the cubic perovskite composite oxide, and It, the peak intensity on the (004) plane corresponding to the tetragonal perovskite composite oxide, then the condition 1 < Ic / It < 2 is satisfied. As a result, in the multilayer ceramic capacitor 1, the proportion of cubic perovskite composite oxide is somewhat higher than that of tetragonal perovskite composite oxide in the crystal grains 40 of the dielectric ceramic layer 20 of the effective portion 10B, thus increasing the effective capacitance of the multilayer ceramic capacitor 1.

[0071] When Ic / It ≤ 1, the proportion of cubic perovskite-type composite oxide in the crystalline grains 40 of the dielectric ceramic layer 20 of the effective portion 10B does not become higher than that of tetragonal perovskite-type composite oxide, and therefore the effective capacitance of the multilayer ceramic capacitor 1 does not increase.

[0072] When Ic / It ≥ 2, the proportion of cubic perovskite composite oxide becomes too high compared to tetragonal perovskite composite oxide in the crystalline grains 40 of the dielectric ceramic layer 20 of the effective portion 10B. As a result, the effective capacitance of the multilayer ceramic capacitor 1 increases in terms of the rate of change of capacitance, but decreases in terms of the absolute value of capacitance. In addition, the nominal capacitance of the multilayer ceramic capacitor 1 decreases.

[0073] In the multilayer ceramic capacitor 1, it is preferable that 1.1 < Ic / It < 1.9 is satisfied.

[0074] For the multilayer ceramic capacitor 1, the peak intensity originating from the crystal structure of the dielectric ceramic layer 20 in the effective portion 10B is measured using X-ray diffraction in the following manner. First, the multilayer ceramic capacitor 1 is embedded in a thermosetting resin and then polished to expose the LW cross-section (see Figure 4) along the length L and width W of the effective portion 10B. Next, an X-ray diffraction chart showing the crystal structure of the dielectric ceramic layer 20 is obtained using X-ray diffraction on the exposed LW cross-section of the effective portion 10B at room temperature (for example, in a temperature range of 20°C to 30°C). Then, the peak intensity Ic on the (400) plane corresponding to the cubic perovskite composite oxide and the peak intensity It on the (004) plane corresponding to the tetragonal perovskite composite oxide are measured in the obtained X-ray diffraction chart. In the multilayer ceramic capacitor 1, the above-described X-ray diffraction chart satisfies 1 < Ic / It < 2.

[0075] When measuring the peak intensity derived from the crystal structure in the dielectric ceramic layer 20 of the effective portion 10B, irradiating the LW cross-section of the effective portion 10B with X-rays, as described above, is done to reduce the influence of the outer layer 10C compared to, for example, irradiating the WT cross-section of the effective portion 10B with X-rays. In this way, when irradiating the LW cross-section of the effective portion 10B with X-rays, the influence of the outer layer 10C is reduced, allowing for a larger X-ray irradiation area. A larger X-ray irradiation area leads to improved accuracy in peak intensity measurement.

[0076] When irradiating the LW cross-section of the effective portion 10B with X-rays, the target of the X-ray irradiation may be only the dielectric ceramic layer 20, only the internal electrode layer 30, or both the dielectric ceramic layer 20 and the internal electrode layer 30. In any case, an X-ray diffraction chart showing the crystal structure of the dielectric ceramic layer 20 can be extracted by analysis.

[0077] As described above, in the multilayer ceramic capacitor 1, in the dielectric ceramic layer 20 of the effective portion 10B, rare earth elements (Re) are solid-dissolved in at least the central region of the grain 42, and the condition 1 < Ic / It < 2 is satisfied, thus enabling the realization of a multilayer ceramic capacitor with a long high-temperature load life and a large effective capacitance.

[0078] In the multilayer ceramic capacitor 1, when the lattice volume Vb is measured by X-ray diffraction for the dielectric ceramic layer 20 of the effective portion 10B, it is 64.1 Å. ３ ≤Vb ≤ 64.6 Å ３ (6.41 x 10 －２９ I understand ３ ≤ Vb ≤ 6.46 × 10 －２９ I understand ３ It is preferable that the following conditions are met. In this case, the high-temperature load life of the multilayer ceramic capacitor 1 will be extended.

[0079] Vb < 64.1 Å ３ (6.41 x 10 －２９ I understand ３ In this case, the high-temperature load life of the multilayer ceramic capacitor 1 is unlikely to be extended.

[0080] Vb > 64.6 Å ３ (6.46 x 10 －２９ I understand ３ In this case, the high-temperature load life of the multilayer ceramic capacitor 1 is unlikely to be extended.

[0081] In the multilayer ceramic capacitor 1, 64.4 Å ３ ≤Vb ≤ 64.6 Å ３ (6.44 x 10 －２９ I understand ３ ≤ Vb ≤ 6.46 × 10 －２９ I understand ３ It is more preferable that the following conditions are met.

[0082] For the multilayer ceramic capacitor 1, the lattice volume Vb in the dielectric ceramic layer 20 of the effective portion 10B is determined by performing Rietveld analysis on the X-ray diffraction chart used when measuring the peak intensity by X-ray diffraction, as described above.

[0083] Regarding the lattice volume, it is appropriate to determine it using the dielectric ceramic layer 20 of the effective portion 10B, where the voltage load is actually applied, within the inner layer 10A, rather than the dielectric ceramic layer 20 of the outer layer 10C. In the multilayer ceramic capacitor 1, (1) stress is easily applied to the dielectric ceramic layer 20 of the effective portion 10B due to shrinkage of the internal electrode layer 30 that occurs during the firing process during manufacturing, and (2) elements easily diffuse from the internal electrode layer 30 to the dielectric ceramic layer 20 of the effective portion 10B during the firing process during manufacturing. For these reasons, the lattice volume of the dielectric ceramic layer 20 of the effective portion 10B is more likely to change than the lattice volume of the dielectric ceramic layer 20 of the outer layer 10C. In other words, in the multilayer ceramic capacitor 1, the lattice volume of the dielectric ceramic layer 20 is likely to differ between the effective portion 10B and the outer layer 10C. Based on the above, in designing the reliability of the multilayer ceramic capacitor 1, it is appropriate to determine the lattice volume using the dielectric ceramic layer 20 of the effective portion 10B, rather than the dielectric ceramic layer 20 of the outer layer 10C.

[0084] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains rare earth elements (Re) and titanium (Ti), in the dielectric ceramic layer 20 of the effective portion 10B, the region formed from the interface of three or more adjacent grains 42 is defined as the triple point region TJ (see Figure 5B), the region centered on the same plane as the interface of two adjacent grains 42, with a width of 10 nm that does not include the triple point region TJ, is defined as the grain boundary region GB (see Figure 5B), and the region within the grain interior of the grain 42 that does not include the triple point region TJ and the grain boundary region GB is defined as the intragrain region GI (see Figure 5B), and it is preferable that GI(Re / Ti) > 0.005 is satisfied when the atomic concentration ratio of the rare earth element (Re) to titanium (Ti) in the intragrain region GI is defined as GI(Re / Ti). In this case, the rare earth element (Re) is uniformly dissolved throughout the entire grain 42, which extends the high-temperature load life of the multilayer ceramic capacitor 1.

[0085] When GI(Re / Ti) ≤ 0.005, it is difficult for the rare earth element (Re) to be uniformly dissolved throughout the entire grain 42, and therefore the high-temperature load life of the multilayer ceramic capacitor 1 is not likely to be extended.

[0086] In the multilayer ceramic capacitor 1, it is more preferable that 0.005 < GI(Re / Ti) ≤ 0.1 is satisfied, even more preferable that 0.007 ≤ GI(Re / Ti) ≤ 0.1 is satisfied, and particularly preferable that 0.01 ≤ GI(Re / Ti) ≤ 0.07 is satisfied.

[0087] When the perovskite-type composite oxide constituting the crystal grains 40 contains a combination of multiple types of rare earth elements (Re), it is preferable that the sum of the atomic concentrations of the multiple types of rare earth elements (Re) satisfies GI(Re / Ti) > 0.005, more preferably 0.005 < GI(Re / Ti) ≤ 0.1, even more preferably 0.007 ≤ GI(Re / Ti) ≤ 0.1, and particularly preferably 0.01 ≤ GI(Re / Ti) ≤ 0.07.

[0088] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains calcium (Ca) and titanium (Ti), it is preferable that in the dielectric ceramic layer 20 of the effective portion 10B, when the atomic concentration ratio of calcium (Ca) to titanium (Ti) in the intragranular region GI is defined as GI(Ca / Ti), the condition 0.005 ≤ GI(Ca / Ti) ≤ 0.1 is satisfied.

[0089] If GI(Ca / Ti) < 0.005 or GI(Ca / Ti) > 0.1, the reliability of the multilayer ceramic capacitor 1 at high temperatures tends to decrease.

[0090] When GI(Ca / Ti) > 0.1, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0091] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains strontium (Sr) and titanium (Ti), it is preferable that in the dielectric ceramic layer 20 of the effective portion 10B, when the atomic concentration ratio of strontium (Sr) to titanium (Ti) in the intragranular region GI is defined as GI(Sr / Ti), the condition 0.005 ≤ GI(Sr / Ti) ≤ 0.1 is satisfied.

[0092] If GI(Sr / Ti) < 0.005 or GI(Sr / Ti) > 0.1, the reliability of the multilayer ceramic capacitor 1 at high temperatures tends to decrease.

[0093] When GI(Sr / Ti) > 0.1, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0094] In the multilayer ceramic capacitor 1, if the perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba) and titanium (Ti), and further contains at least one of calcium (Ca) and strontium (Sr), it is preferable that in the dielectric ceramic layer 20 of the effective portion 10B, when the atomic concentration ratio of the total of barium (Ba), calcium (Ca), and strontium (Sr) to titanium (Ti) in the intragranular region GI is defined as GI(Ba+Ca+Sr / Ti), the following condition is satisfied: 1.00 ≤ GI(Ba+Ca+Sr / Ti) ≤ 1.03. For example, if the perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba), titanium (Ti), and calcium (Ca), but does not contain strontium (Sr), GI(Ba+Ca+Sr / Ti) may be expressed as GI(Ba+Ca / Ti).

[0095] When GI(Ba+Ca+Sr / Ti) < 1.00, the insulation resistance of the multilayer ceramic capacitor 1 tends to decrease.

[0096] When GI(Ba+Ca+Sr / Ti) > 1.03, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0097] For the multilayer ceramic capacitor 1, the various atomic concentration ratios in the intragranular region GI of the dielectric ceramic layer 20 of the effective portion 10B are determined by image analysis of the mapping image used to confirm the distribution state of rare earth elements (Re) in the grain 42, as described above. In this case, the various atomic concentration ratios in the intragranular region GI are determined by point analysis of any location in the intragranular region GI of the dielectric ceramic layer 20 of the effective portion 10B, excluding the triple point region TJ and the grain boundary region GB. Note that the triple point region TJ refers to the region containing the triple point, not the triple junction itself. Also, the grain boundary region GB refers to the region containing the grain boundary 41, not the grain boundary 41 itself.

[0098] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains rare earth elements (Re) and titanium (Ti), it is preferable that the average atomic concentration ratio of the rare earth element (Re) to titanium (Ti) in the entire dielectric ceramic layer 20 of the effective portion 10B satisfies 0.007 ≤ GD(Re / Ti) ≤ 0.1. In this case, the rare earth element (Re) is uniformly dissolved in the entire dielectric ceramic layer 20, thus extending the high-temperature load life of the multilayer ceramic capacitor 1.

[0099] When GD(Re / Ti) < 0.007, it is difficult for the rare earth element (Re) to be uniformly dissolved throughout the dielectric ceramic layer 20, and therefore the high-temperature load life of the multilayer ceramic capacitor 1 is not easily extended.

[0100] When GD(Re / Ti) > 0.1, different phases are more likely to be generated in the dielectric ceramic layer 20, which tends to reduce the reliability of the multilayer ceramic capacitor 1 at high temperatures.

[0101] In the multilayer ceramic capacitor 1, it is more preferable that 0.01 ≤ GD(Re / Ti) ≤ 0.07 is satisfied.

[0102] When the perovskite-type composite oxide constituting the crystal grains 40 contains a combination of multiple types of rare earth elements (Re), it is preferable that the sum of the atomic concentrations of the multiple types of rare earth elements (Re) satisfies 0.007 ≤ GD(Re / Ti) ≤ 0.1, and more preferably that it satisfies 0.01 ≤ GD(Re / Ti) ≤ 0.07.

[0103] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains calcium (Ca) and titanium (Ti), it is preferable that the average atomic concentration ratio of calcium (Ca) to titanium (Ti) in the entire dielectric ceramic layer 20 of the effective portion 10B satisfies 0.005 ≤ GD(Ca / Ti) ≤ 0.1, where GD(Ca / Ti) is the average atomic concentration ratio of calcium (Ca) to titanium (Ti).

[0104] If GD(Ca / Ti) < 0.005 or GD(Ca / Ti) > 0.1, the reliability of the multilayer ceramic capacitor 1 at high temperatures tends to decrease.

[0105] When GD(Ca / Ti) > 0.1, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0106] In the multilayer ceramic capacitor 1, when the perovskite-type composite oxide constituting the crystal grains 40 contains strontium (Sr) and titanium (Ti), it is preferable that in the entire dielectric ceramic layer 20 of the effective portion 10B, the average atomic concentration ratio of strontium (Sr) to titanium (Ti) is GD(Sr / Ti), and the condition 0.005 ≤ GD(Sr / Ti) ≤ 0.1 is satisfied.

[0107] If GD(Sr / Ti) < 0.005 or GD(Sr / Ti) > 0.1, the reliability of the multilayer ceramic capacitor 1 at high temperatures tends to decrease.

[0108] When GD(Sr / Ti) > 0.1, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0109] In the multilayer ceramic capacitor 1, if the perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba) and titanium (Ti), and further contains at least one of calcium (Ca) and strontium (Sr), it is preferable that in the entire dielectric ceramic layer 20 of the effective portion 10B, when the average atomic concentration ratio of the total of barium (Ba), calcium (Ca), and strontium (Sr) to titanium (Ti) is GD(Ba+Ca+Sr / Ti), the condition 1.00 ≤ GD(Ba+Ca+Sr / Ti) ≤ 1.03 is satisfied. For example, if the perovskite-type composite oxide constituting the crystal grains 40 contains barium (Ba), titanium (Ti), and calcium (Ca), but does not contain strontium (Sr), GD(Ba+Ca+Sr / Ti) may be expressed as GD(Ba+Ca / Ti).

[0110] When GD(Ba+Ca+Sr / Ti) < 1.00, the insulation resistance of the multilayer ceramic capacitor 1 tends to decrease.

[0111] When GD(Ba+Ca+Sr / Ti) > 1.03, the effective capacitance and nominal capacitance of the multilayer ceramic capacitor 1 tend to be small.

[0112] For a multilayer ceramic capacitor 1, the average atomic concentration ratios of various elements in the entire dielectric ceramic layer 20 of the effective portion 10B are determined by the following method. First, the effective portion 10B is obtained by polishing the multilayer ceramic capacitor 1. Next, the obtained effective portion 10B is pulverized, and the pulverized internal electrode layer 30 is removed to obtain the pulverized dielectric ceramic layer 20. Subsequently, the atomic concentrations of various elements are measured by performing a compositional analysis of the pulverized dielectric ceramic layer 20 using dielectric coupled plasma atomic emission spectroscopy (ICP-AES). In this case, for example, the atomic concentrations of various elements are measured using the dielectric coupled plasma atomic emission spectrometer "iCAP6300" manufactured by Thermo Fisher Scientific Inc., with a measurement wavelength range of 166 nm or more and 847 nm or less. Then, the atomic concentration ratio of the target element is determined from the atomic concentrations of the obtained elements, and this is taken as the average atomic concentration ratio of the various elements in the entire dielectric ceramic layer 20 of the effective part 10B.

[0113] Furthermore, when determining the average atomic concentration ratios of various elements in the entire dielectric ceramic layer 20 of the effective portion 10B, if it is difficult to perform compositional analysis on the pulverized dielectric ceramic layer 20 using dielectric-coupled plasma emission spectroscopy (ICP-AES), the compositional analysis will be performed using wavelength-dispersive X-ray fluorescence spectroscopy (WD-XRF). In this case, for example, pretreatment will be performed using the glass bead method, and the atomic concentrations of various elements will be measured with a measurement diameter of 30 nmφ.

[0114] The average thickness of the dielectric ceramic layer 20 is not particularly limited, but is preferably 3.5 μm or less, more preferably 2.0 μm or less, even more preferably 1.0 μm or less, and particularly preferably 0.8 μm or less. The average thickness of the dielectric ceramic layer 20 is preferably within the above range, especially in the effective portion 10B. In this case, the deterioration of the insulating properties due to the dielectric ceramic layer 20 in the multilayer ceramic capacitor 1 is suppressed. Furthermore, in the multilayer ceramic capacitor 1, the dielectric ceramic layer 20 is made thinner, which makes it easier to increase the capacitance.

[0115] The average thickness of the dielectric ceramic layer 20 may be, for example, 0.2 μm or more.

[0116] The average thickness of the dielectric ceramic layer 20 is measured by the following method. First, the multilayer ceramic capacitor 1 is embedded in a thermosetting resin and then polished to expose the WT cross-section (see Figure 3) of the base body 10 (effective portion 10B) along the width direction W and thickness direction T. Next, the exposed WT cross-section of the base body 10 is observed with a scanning electron microscope (SEM), and a center line is drawn passing through the center of the WT cross-section of the base body 10 along the thickness direction T. Two lines are then drawn along the thickness direction T at equally spaced positions on both sides of this center line in the width direction W. The thickness of the dielectric ceramic layer 20 is then measured along these five lines, and the average of the five measured values ​​is taken as the average thickness of the dielectric ceramic layer 20.

[0117] The number of dielectric ceramic layers 20 is not particularly limited, but may be, for example, 50 or more layers and 1000 or less layers.

[0118] The average grain size of the grains 42 in the dielectric ceramic layer 20 is not particularly limited, but is preferably 200 nm or more and 500 nm or less.

[0119] The average grain size of the grains 42 in the dielectric ceramic layer 20 is measured by analyzing cross-sectional images scanned with a scanning electron microscope (SEM). For example, the average grain size of the grains 42 is measured using software that measures average grain size in accordance with the "JIS G 0551:2013" standard.

[0120] The internal electrode layer 30 contains, for example, a conductive metal. Examples of conductive metals included in the internal electrode layer 30 include nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), and alloys containing at least one of these.

[0121] The internal electrode layer 30 may contain components other than conductive metals. Examples of other components include ceramic components that act as co-materials. Examples of ceramic components include perovskite-type composite oxides contained in the dielectric ceramic layer 20, such as barium titanate (BaTiO2). ３ Examples include compounds of the ) system.

[0122] The average thickness of the internal electrode layer 30 is not particularly limited, but may be, for example, 0.3 μm or more and 0.7 μm or less. It is preferable that the average thickness of the internal electrode layer 30 be within the above range, especially in the effective portion 10B. In this case, defects such as breaks in the internal electrode layer 30 are suppressed in the multilayer ceramic capacitor 1. Furthermore, in the multilayer ceramic capacitor 1, the proportion of the electrically functional dielectric ceramic layer 20 in the effective portion 10B is less likely to decrease, thus reducing the capacitance.

[0123] The average thickness of the internal electrode layer 30 is determined by measuring the thickness of the internal electrode layer 30 along a total of five lines used when measuring the average thickness of the dielectric ceramic layer 20, as described above, and taking the average of the five obtained measurements.

[0124] The configuration of the external electrodes 11 and 12 is not particularly limited. The external electrodes 11 and 12 may have a laminated structure in which, for example, a base layer, a first plating layer, and a second plating layer are sequentially laminated from the end face side of the base body 10.

[0125] The base layer contains metals such as nickel (Ni) and copper (Cu). In addition to the above-mentioned metals, the base layer may also contain ceramic powder that acts as a co-material.

[0126] The first plating layer is, for example, a nickel (Ni) plating layer.

[0127] The second plating layer is, for example, a tin (Sn) plating layer.

[0128] A conductive resin layer may be provided between the underlayer and the first plating layer. The conductive resin layer is, for example, a layer containing conductive metal particles such as copper (Cu), silver (Ag), and nickel (Ni), and a resin.

[0129] The external electrodes 11 and 12 are not particularly limited in their form, as long as they are electrically connected to the internal electrode layer 30 and function as external input / output terminals.

[0130] [Manufacturing Method for Multilayer Ceramic Capacitors] The manufacturing method for the multilayer ceramic capacitor of the present invention is not particularly limited, as long as the above-mentioned requirements are satisfied.

[0131] The present invention provides a method for manufacturing a multilayer ceramic capacitor, comprising the steps of: producing a green sheet containing, for example, a rare earth element (Re) and barium (Ba), and further containing at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr) (green sheet production step); applying a conductive paste to the surface of the green sheet to obtain a green sheet with an internal electrode pattern formed on it (internal electrode pattern formation step); stacking and pressing a plurality of green sheets to obtain a stacked block (stacking step); cutting the obtained stacked block to obtain a stacked chip (cutting step); subjecting the obtained stacked chip to a binder removal process and a firing process to obtain a base body (firing step); and forming external electrodes on the obtained base body (external electrode formation step). Details of each step are described below.

[0132] <Green Sheet Manufacturing Process> In the green sheet manufacturing process, a green sheet is produced that contains rare earth elements (Re) and barium (Ba), as well as at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr).

[0133] The green sheet is a precursor to the dielectric ceramic layer, and becomes the dielectric ceramic layer after firing.

[0134] The green sheet contains the main component raw materials and additive raw materials of the dielectric ceramic layer.

[0135] The method for producing the green sheet is not particularly limited. For example, a dielectric material may be prepared by mixing an additive material with a main component material, a binder and a solvent may be added to the obtained dielectric material and mixed to form a slurry, and a green sheet may be formed from the obtained slurry.

[0136] The main raw material is a perovskite-type complex oxide powder, for example, barium titanate (BaTiO2). ３ Powders of ) compounds are used. Perovskite-type complex oxides may be synthesized by known ceramic synthesis methods such as solid-phase reaction methods, hydrothermal synthesis methods, and alkoxide methods, using at least one known ceramic raw material selected from the group consisting of oxides, carbonates, hydroxides, nitrates, organic acid salts, alkoxides, and chelating compounds.

[0137] Barium titanate (BaTiO) is a perovskite-type composite oxide. ３ When synthesizing ) compounds, for example, in addition to barium (Ba) raw materials, titanium (Ti) raw materials, and rare earth element (Re) raw materials, at least one of calcium (Ca) raw materials and strontium (Sr) raw materials is wet-mixed in a ball mill, dried, and then heated.

[0138] As barium (Ba) raw materials, known ceramic raw materials such as barium (Ba) oxides, carbonates, and acetates can be used.

[0139] As titanium (Ti) raw materials, known ceramic raw materials such as titanium (Ti) oxides, carbonates, acetates, and chlorides can be used.

[0140] As rare earth element (Re) raw materials, known ceramic raw materials such as oxides, carbonates, and acetates of rare earth elements (Re) can be used.

[0141] As calcium (Ca) raw materials, known ceramic raw materials such as calcium (Ca) oxides and carbonates can be used.

[0142] As strontium (Sr) raw materials, known ceramic raw materials such as strontium (Sr) oxides and carbonates can be used.

[0143] As additive raw materials, for example, raw materials for other additive components such as vanadium (V), manganese (Mn), magnesium (Mg), silicon (Si), and aluminum (Al) are used. Furthermore, barium titanate (BaTiO) is used as a perovskite-type composite oxide. ３ When using a compound of the ) type, use barium titanate (BaTiO ３ To adjust the composition of the ) system compound, barium carbonate (BaCO3) ３ Barium (Ba) raw materials such as ) and titanium dioxide (TiO) ２ Titanium (Ti) raw materials such as ) may be added as additive raw materials.

[0144] When adding and mixing a binder and solvent to a dielectric material to form a slurry, known methods may be used, for example, an organic binder and an organic solvent may be mixed with the dielectric material.

[0145] As the organic binder, known binders such as polyvinyl butyral-based binders can be used.

[0146] As organic solvents, known solvents such as toluene and ethyl alcohol can be used.

[0147] Additives such as plasticizers may be added to the slurry as needed.

[0148] When forming the green sheet from the slurry, known methods such as the doctor blade method or the lip method may be used.

[0149] <Internal electrode pattern formation process> In the internal electrode pattern formation process, a conductive paste is applied to the surface of a green sheet to obtain a green sheet with an internal electrode pattern formed on it.

[0150] The internal electrode pattern becomes the internal electrode layer after the firing process.

[0151] The conductive paste contains, for example, a conductive metal. Examples of conductive metals used in the conductive paste include nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), and alloys containing at least one of these.

[0152] The conductive paste may further contain a ceramic component that acts as a co-material in addition to the conductive metal described above. As the ceramic component, for example, the main component raw material of a dielectric ceramic layer may be used.

[0153] When applying the conductive paste, known methods such as screen printing or gravure printing may be used.

[0154] <Lamination Process> In the lamination process, multiple green sheets are laminated and compressed to obtain a laminated block.

[0155] As the green sheet, a green sheet with an internal electrode pattern formed on it is used, but a portion of the green sheet without an internal electrode pattern may also be used.

[0156] When laminating and pressing multiple green sheets together, known methods may be used.

[0157] <Cutting Process> In the cutting process, the obtained laminated block is cut to obtain laminated chips.

[0158] When cutting the laminated block, it is sufficient to obtain a laminated chip of a predetermined size and to ensure that at least a portion of the internal electrode pattern is exposed on the end face of the laminated chip.

[0159] <Firing Process> In the firing process, the obtained laminated chips are subjected to a binder removal process and a firing process to obtain a base material.

[0160] During the firing process, the green sheet and the internal electrode pattern are co-sintered to form a dielectric ceramic layer and an internal electrode layer, respectively.

[0161] The conditions for performing the binder removal process on the multilayer chip may be determined, for example, according to the type of organic binder contained in the green sheet and the internal electrode pattern.

[0162] When performing a firing treatment on a laminated chip, it is preferable to do so at a temperature at which the laminated chip becomes sufficiently densified. For example, the firing treatment on the laminated chip may be performed under conditions of holding it at a temperature of 1200°C or higher and 1300°C or lower for 1 hour or more and 10 hours or less.

[0163] When firing the stacked chips, a perovskite-type composite oxide, such as barium titanate (BaTiO), is used. ３ It is preferable to carry out the process in an atmosphere in which the compound is not reduced and oxidation of the internal electrode pattern, such as oxidation of conductive metals, is suppressed. For example, an atmosphere with an oxygen partial pressure of 1.9 × 10⁻⁶. －１１ MPa or higher, 6.4 x 10 －９ Nitrogen (N) at a pressure of MPa or less ２ )-hydrogen (H ２ ) - Water vapor (H ２ O) The laminated chips may be subjected to a firing process in an airflow.

[0164] When performing the firing process on the laminated chips, for example, it may be carried out under conditions of a heating rate of 400°C / min. By increasing the heating rate during the firing process, grain growth can be suppressed.

[0165] When firing laminated chips, by including large amounts of glass components such as silicon (Si) and aluminum (Al) as additive raw materials, rare earth elements (Re) can be dissolved and discharged into the grain boundary region GB (see Figure 5B).

[0166] The laminated chips after firing may be subjected to further annealing treatment.

[0167] <External electrode formation process> In the external electrode formation process, external electrodes are formed on the obtained base body.

[0168] In forming the external electrodes, known methods may be used. For example, external electrodes may be formed by applying and baking a conductive paste containing at least one metal selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), etc., to the end face of the base body exposed by drawing out the internal electrode layer. Alternatively, external electrodes may be formed by applying a conductive paste to both end faces of the laminated chip before firing and then performing a firing process. Furthermore, electrodes formed by the above methods may be used as a base layer, and a plating film of nickel (Ni), tin (Sn), etc., may be formed on top of it.

[0169] The Ic / It ratio described above (Ic: peak intensity on the (400) plane corresponding to the cubic perovskite composite oxide among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, and It: peak intensity on the (004) plane corresponding to the tetragonal perovskite composite oxide among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion) can be controlled by the amount and state of solid solution of rare earth elements (Re), calcium (Ca), strontium (Sr), etc., in relation to the crystal grains of the dielectric ceramic layer. For example, by increasing the amount of solid solution of rare earth elements (Re), calcium (Ca), strontium (Sr), etc., in the crystalline grains of the dielectric ceramic layer, or by ensuring that the solid solution state of rare earth elements (Re), calcium (Ca), strontium (Sr), etc., in the crystalline grains of the dielectric ceramic layer is such that the rare earth elements (Re), calcium (Ca), strontium (Sr), etc., are solidly dissolved in at least the central region of the grain, it is possible to achieve 1 < Ic / It < 2.

[0170] The amount and state of solid solution of rare earth elements (Re), calcium (Ca), strontium (Sr), etc., in the crystalline particles of the dielectric ceramic layer can be controlled by adjusting the amount (blending ratio) of rare earth element (Re), calcium (Ca), and strontium (Sr) raw materials added, or by adjusting the heating conditions, during the process of producing the dielectric raw materials described above (green sheet production process), and by adjusting the firing conditions during the process of firing the laminated chips described above (firing process). For example, in the process of producing the dielectric raw materials described above (green sheet production process), by increasing the amount of rare earth element (Re) raw materials, calcium (Ca) raw materials, and strontium (Sr) raw materials added (mixing amount), or by heating at a high temperature after mixing (stirring) each raw material, or by firing at a high temperature in the process of firing the laminated chip described above (firing process), it is possible to make the dielectric ceramic layer of the effective part in a state where rare earth elements (Re), calcium (Ca), strontium (Sr), etc. are solidly dissolved in at least the central region of the grain.

[0171] The multilayer ceramic capacitor of the present invention is manufactured as described above.

[0172] The multilayer ceramic capacitor of the present invention is not limited to the above-described form, and various applications and modifications can be made within the scope of the present invention regarding the configuration, manufacturing conditions, etc., of the multilayer ceramic capacitor.

[0173] The following are examples that more specifically disclose the multilayer ceramic capacitor of the present invention. However, the present invention is not limited to the following examples.

[0174] [Examples 1-7, Comparative Examples 1-4] The multilayer ceramic capacitors of Examples 1-7 and Comparative Examples 1-4 were manufactured according to the following procedure.

[0175] First, barium carbonate (BaCO2) ３ ) powder, titanium dioxide (TiO ２ ) powder, calcium carbonate (CaCO3) ３ ) powder, and dysprosium oxide (Dy ２ O３ The raw material powder was wet-mixed in a ball mill, and the dried powder was heated to obtain dielectric powder.

[0176] Next, a polyvinyl butyral-based binder and a plasticizer were added to the obtained dielectric powder, and then toluene and ethyl alcohol were added to form a slurry using a wet mill. This slurry was then molded to obtain a green sheet. The obtained green sheet had a thickness of 1.7 μm after sintering and densification.

[0177] Next, a conductive paste mainly composed of nickel (Ni) was screen printed onto the surface of the obtained green sheet to form an internal electrode pattern for the conductive paste layer, which would serve as the internal electrode layer.

[0178] Subsequently, green sheets with conductive paste layers formed on their surfaces were stacked so that the sides with the conductive paste layers extended were alternating. Layers of green sheets without conductive paste layers were then placed above and below them, and the entire assembly was pressed together to obtain a laminated block.

[0179] Next, the resulting laminated block was cut to obtain laminated chips. The cutting from the laminated block to the laminated chip was done so that the size of the manufactured multilayer ceramic capacitor would be 3.2 mm in length, 1.6 mm in width, and 1.6 mm in thickness.

[0180] Next, nitrogen (N) is added to the resulting stacked chip. ２ The binder was removed by burning it off through heat treatment at 280°C in an airflow. Subsequently, the oxygen partial pressure was 1.6 × 10⁻⁶. －９ Nitrogen (N) at MPa ２ )-hydrogen (H ２ ) - Water vapor (H ２ O) The laminated chips were subjected to a firing treatment at 1260°C for 2 hours in an airflow. This yielded the raw material.

[0181] Then, a conductive paste mainly composed of copper (Cu) was applied to the end face of the base body, which was exposed after the internal electrode layer was pulled out. This paste was then baked at 800°C to form a base layer, and then a nickel (Ni) plating layer and a tin (Sn) plating layer were sequentially formed on the surface of the base layer. This formed the external electrode on the surface of the base body.

[0182] As described above, multilayer ceramic capacitors of Examples 1 to 7 and Comparative Examples 1 to 4 were manufactured. The obtained multilayer ceramic capacitors had dimensions of 3.2 mm in length, 1.6 mm in width, and 1.6 mm in thickness. The average thickness of the dielectric ceramic layer was 1.7 μm.

[0183] In manufacturing the multilayer ceramic capacitors of Examples 1 to 7 and Comparative Examples 1 to 4, the amount and state of solid solution of dysprosium (Dy) (rare earth element (Re)) and calcium (Ca) in the crystalline particles of the dielectric ceramic layer were controlled so that the Ic / It (Ic: peak intensity on the (400) plane corresponding to the cubic perovskite composite oxide among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, It: peak intensity on the (004) plane corresponding to the tetragonal perovskite composite oxide among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion) satisfy the values ​​shown in Table 1. The amount and state of solid solution of dysprosium (Dy) (rare earth element (Re)) and calcium (Ca) in the crystalline particles of the dielectric ceramic layer were controlled in the process of obtaining the dielectric powder described above, so that dysprosium oxide (Dy) ２ O ３ ) powder and calcium carbonate (CaCO3) ３ This was controlled by adjusting the amount of powder added (mixing ratio), adjusting the heating conditions, and by adjusting the firing conditions during the firing process of the laminated chips described above.

[0184] [Evaluation] The multilayer ceramic capacitors of Examples 1 to 7 and Comparative Examples 1 to 4 were evaluated as follows. The results are shown in Table 1.

[0185] <Distribution of Rare Earth Elements (Re)> For multilayer ceramic capacitors, the distribution of rare earth elements (Re) in the grains of the dielectric ceramic layer in the effective portion was confirmed using the method described above. A JEM-F200 / Noran System 7 electron microscope manufactured by JEOL Ltd. was used for this purpose. In the obtained mapping image, a "○" indicated that rare earth elements (Re) were distributed in at least the central region of the grains, and a "×" indicated that rare earth elements (Re) were not distributed in the central region of the grains.

[0186] <Peak Intensity Ratio Ic / It> For multilayer ceramic capacitors, the peak intensity ratio Ic / It, derived from the crystal structure of the dielectric ceramic layer in the effective portion, was determined by the method described above. A Rigaku Corporation "SmartLab Small Region XRD" X-ray diffractometer was used for this purpose. The collimator diameter was 50 μmφ, and the measurement range was set to 20° or more and 85° or less (θ ± 180°).

[0187] <Lattice Volume Vb> For multilayer ceramic capacitors, the lattice volume Vb in the dielectric ceramic layer of the effective portion was determined by the method described above.

[0188] <Atomic Concentration Ratios> For multilayer ceramic capacitors, the atomic concentration ratios GI(Re / Ti), GI(Ca / Ti), and GI(Ba+Ca / Ti) in the intragranular region of the dielectric ceramic layer of the entire effective part were determined by the method described above. Although not shown in Table 1, the average atomic concentration ratios GD(Re / Ti), GD(Ca / Ti), and GD(Ba+Ca / Ti) in the dielectric ceramic layer of the effective part were approximately the same as GI(Re / Ti), GI(Ca / Ti), and GI(Ba+Ca / Ti), respectively.

[0189] <High-Temperature Load Life (MTTF Ratio)> First, a Highly Accelerated Life Test (HALT) was performed on the multilayer ceramic capacitors to determine the Mean Time To Failure (MTTF). In the Highly Accelerated Life Test (HALT), a high-temperature load was applied to the sample (multilayer ceramic capacitor) under the conditions of a test temperature of 175°C and a test voltage of 50V. The time at which the insulation resistance of the sample fell below 20kΩ was defined as the failure time. The above procedure was performed on 72 samples manufactured under the same conditions to determine the failure time for each sample.

[0190] Next, the data from each sample was plotted on Weibull probability paper to obtain the Weibull distribution. The relationship between failure time and cumulative failure rate was linearly regressed on the obtained Weibull distribution, and its slope was determined as the shape parameter m. Furthermore, the failure time t at which the cumulative failure rate reached 63.2% was read from the obtained Weibull distribution. Finally, the mean time to failure (MTTF) at a test voltage of 50V was determined using the shape parameter m and the failure time t.

[0191] The mean time to failure (MTTF) of each example of the multilayer ceramic capacitor obtained as described above was then used to determine the ratio (MTTF ratio) to the mean time to failure (MTTF) of the multilayer ceramic capacitor of Example 5.

[0192] <Effective Capacitance Ratio> The effective capacitance of a multilayer ceramic capacitor was measured at an electric field strength of 10 kV / mm under the conditions of frequency: 1 kHz, effective voltage: 1 Vrms, using an LCR meter "E4980A" manufactured by KEYSIGHT Corporation.

[0193] The ratio (effective capacitance ratio) of the effective capacitance of each example's multilayer ceramic capacitor to the effective capacitance of the multilayer ceramic capacitor of Comparative Example 4 was determined.

[0194]

[0195] As shown in Table 1, in the multilayer ceramic capacitors of Examples 1 to 7, where the dielectric ceramic layer of the effective portion has a solid solution of rare earth elements (Re) in at least the central region of the grain, and where 1 < Ic / It < 2, it was confirmed that the high-temperature load life was long (high MTTF ratio) and the effective capacitance was large (high effective capacitance ratio). Furthermore, in the multilayer ceramic capacitors of Examples 1 to 7, where GI(Re / Ti) > 0.005, it was confirmed that the rare earth elements (Re) were uniformly solid-dissolved throughout the entire grain. ３ ≤Vb ≤ 64.6 Å ３ While satisfying the above conditions, the multilayer ceramic capacitors of Examples 1, 2, 3, and 7, which have a large GI (Re / Ti) (for example, GI (Re / Ti) ≥ 0.05), were found to have a longer high-temperature load life compared to the multilayer ceramic capacitors of Examples 4, 5, and 6.

[0196] On the other hand, in Comparative Examples 1, 2, and 4, where Ic / It ≤ 1, it was confirmed that the effective capacitance was smaller (effective capacitance ratio was smaller) compared to the multilayer ceramic capacitors of Examples 1 to 7.

[0197] Furthermore, it was confirmed that the multilayer ceramic capacitor of Comparative Example 3 has a so-called core-shell structure in which the rare earth element (Re) is not solid-dissolved in the central region of the grain but solid-dissolved in the peripheral region of the central region. It was confirmed that the multilayer ceramic capacitor of Comparative Example 3, which has such a core-shell structure, has a shorter high-temperature load life (smaller MTF ratio) compared to the multilayer ceramic capacitors of Examples 1 to 7.

[0198] The above evaluation focused on the case where the rare earth element (Re) is dysprosium (Dy). However, similar evaluation results were confirmed for cases where the rare earth element (Re) is yttrium (Y), gadolinium (Gd), holmium (Ho), erbium (Er), or ytterbium (Yb).

[0199] This specification discloses the following:

[0200] <1> A substrate comprising a plurality of dielectric ceramic layers and a plurality of internal electrode layers stacked in the thickness direction, and an external electrode provided on the surface of the substrate and electrically connected to the internal electrode layer, wherein the substrate includes an effective portion in which the plurality of internal electrode layers overlap each other in the thickness direction via the dielectric ceramic layer, the dielectric ceramic layer comprises crystalline particles composed of a perovskite-type composite oxide, the perovskite-type composite oxide contains a rare earth element (Re) and barium (Ba), and further contains at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr), and in the dielectric ceramic layer of the effective portion, when the region surrounded by the grain boundaries of the crystalline particles is defined as a grain, the rare earth element (Re) is solid-dissolved in at least the central region of the grain. A multilayer ceramic capacitor characterized in that, among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, when Ic is the peak intensity on the (400) plane corresponding to the cubic perovskite composite oxide and It is the peak intensity on the (004) plane corresponding to the tetragonal perovskite composite oxide, 1 < Ic / It < 2 is satisfied.

[0201] <2> When the lattice volume Vb is measured by X-ray diffraction for the dielectric ceramic layer of the effective portion described above, it is 64.1 Å. ３ ≤Vb ≤ 64.6 Å ３ A multilayer ceramic capacitor as described in <1> that satisfies the following conditions.

[0202] <3> The multilayer ceramic capacitor according to <1> or <2>, wherein the perovskite-type composite oxide contains titanium (Ti).

[0203] <4> The multilayer ceramic capacitor according to <3>, wherein in the dielectric ceramic layer of the effective portion, a region formed from the interfaces of three or more adjacent grains is defined as a triple point region, a region with a width of 10 nm that does not include the triple point region is defined as a grain boundary region, a region within the grains that does not include the triple point region and the grain boundary region is defined as an intra-grain region, and when the atomic concentration ratio of the rare earth element (Re) to titanium (Ti) in the intra-grain region is defined as GI(Re / Ti), GI(Re / Ti) > 0.005.

[0204] <5> The multilayer ceramic capacitor according to <3> or <4>, wherein in the dielectric ceramic layer of the entire effective portion, when the average atomic concentration ratio of the rare earth element (Re) to titanium (Ti) is GD(Re / Ti), the condition 0.007 ≤ GD(Re / Ti) ≤ 0.1 is satisfied.

[0205] <6> A multilayer ceramic capacitor as described in <5>, satisfying 0.01 ≤ GD(Re / Ti) ≤ 0.07.

[0206] <7> A multilayer ceramic capacitor according to any one of <1> to <6>, wherein the above-mentioned rare earth element (Re) includes at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), and ytterbium (Yb).

[0207] <8> The multilayer ceramic capacitor described in <7>, wherein the rare earth element (Re) contains dysprosium (Dy).

[0208] <9> A multilayer ceramic capacitor according to any one of <1> to <8>, wherein the average thickness of the dielectric ceramic layer is 3.5 μm or less.

[0209] <10> The multilayer ceramic capacitor according to <9>, wherein the average thickness of the dielectric ceramic layer is 2.0 μm or less.

[0210] <11> The multilayer ceramic capacitor according to <10>, wherein the average thickness of the dielectric ceramic layer is 1.0 μm or less.

[0211] <12> The multilayer ceramic capacitor according to <11>, wherein the average thickness of the dielectric ceramic layer is 0.8 μm or less.

[0212] 1 Multilayer ceramic capacitor 10 Base body 10A Inner layer 10B Effective part 10C Outer layer 10a First main surface 10b Second main surface 10c First side surface 10d Second side surface 10e First end surface 10f Second end surface 11, 12 External electrodes 20 Dielectric ceramic layer 30 Internal electrode layer 31 First internal electrode layer 32 Second internal electrode layer 40 Crystal grain 41 Grain boundary 42 Grain GB Grain boundary region GI Intragrain region L Length direction T Thickness direction TJ Triple point region W Width direction

Claims

1. A substrate comprising a plurality of dielectric ceramic layers and a plurality of internal electrode layers stacked in the thickness direction, and an external electrode provided on the surface of the substrate and electrically connected to the internal electrode layer, wherein the substrate includes an effective portion in which the plurality of internal electrode layers overlap each other in the thickness direction via the dielectric ceramic layer, the dielectric ceramic layer comprises crystalline particles composed of a perovskite-type composite oxide, the perovskite-type composite oxide comprises a rare earth element (Re) and barium (Ba), and further comprises at least one of calcium (Ca) and strontium (Sr), and at least one of titanium (Ti) and zirconium (Zr), and in the dielectric ceramic layer of the effective portion, when the region surrounded by the grain boundaries of the crystalline particles is defined as a grain, the rare earth element (Re) is solid-dissolved in at least the central region of the grain. A multilayer ceramic capacitor characterized in that, among the peak intensities measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, when Ic is the peak intensity on the (400) plane corresponding to the cubic perovskite-type composite oxide and It is the peak intensity on the (004) plane corresponding to the tetragonal perovskite-type composite oxide, the condition 1 < Ic / It < 2 is satisfied.

2. When the lattice volume Vb is measured by X-ray diffraction for the dielectric ceramic layer of the effective portion, it is 64.1 Å. ３ ≤Vb ≤ 64.6 Å ３ A multilayer ceramic capacitor according to claim 1, satisfying the requirements.

3. The multilayer ceramic capacitor according to claim 1 or 2, wherein the perovskite-type composite oxide contains titanium (Ti).

4. In the dielectric ceramic layer of the effective portion, a region formed from the interface of three or more adjacent grains is defined as a triple point region, a region with a width of 10 nm that does not include the triple point region is defined as a grain boundary region, a region within the grain of the grain that does not include the triple point region and the grain boundary region is defined as an intra-grain region, and when the atomic concentration ratio of the rare earth element (Re) to titanium (Ti) in the intra-grain region is defined as GI(Re / Ti), the multilayer ceramic capacitor satisfies GI(Re / Ti) > 0.

005.

5. The multilayer ceramic capacitor according to claim 3 or 4, wherein in the dielectric ceramic layer of the entire effective portion, when the average atomic concentration ratio of the rare earth element (Re) to titanium (Ti) is GD(Re / Ti), the condition 0.007 ≤ GD(Re / Ti) ≤ 0.1 is satisfied.

6. The multilayer ceramic capacitor according to claim 5, satisfying 0.01 ≤ GD(Re / Ti) ≤ 0.

07.

7. The multilayer ceramic capacitor according to any one of claims 1 to 6, wherein the rare earth element (Re) includes at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), and ytterbium (Yb).

8. The multilayer ceramic capacitor according to claim 7, wherein the rare earth element (Re) comprises dysprosium (Dy).

9. The multilayer ceramic capacitor according to any one of claims 1 to 8, wherein the average thickness of the dielectric ceramic layer is 3.5 μm or less.

10. The multilayer ceramic capacitor according to claim 9, wherein the average thickness of the dielectric ceramic layer is 2.0 μm or less.

11. The multilayer ceramic capacitor according to claim 10, wherein the average thickness of the dielectric ceramic layer is 1.0 μm or less.

12. The multilayer ceramic capacitor according to claim 11, wherein the average thickness of the dielectric ceramic layer is 0.8 μm or less.

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