Multilayer ceramic electronic components and dielectric ceramic compositions

Abstract

The present invention provides multilayer ceramic electronic components and dielectric ceramic compositions that can ensure reliability. [Solution] The dielectric material comprises a plurality of dielectric particles 30 having a first rare earth element selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, and a second rare earth element selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium, wherein the elemental ratio of the first rare earth element to the second rare earth element is 65:35 to 35:65, and a dielectric layer 11 having a segregated phase 40 mainly composed of silicon oxide at the grain boundary triple points of the plurality of dielectric particles 30, a plurality of internal electrode layers 12 facing each other with the dielectric layer 11 in between, and external electrodes 20a, 20b electrically connected to the plurality of internal electrode layers 12.

Description

[Technical Field]

[0001] This invention relates to multilayer ceramic electronic components and dielectric ceramic compositions. [Background technology]

[0002] In recent years, multilayer ceramic electronic components such as multilayer ceramic capacitors are increasingly being used in applications requiring operation under high voltages of up to 100V, such as large-scale data centers and automotive power systems. Therefore, ensuring reliability under high voltage conditions is becoming increasingly important for the materials that make up these multilayer ceramic electronic components. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-50136 [Overview of the project] [Problems that the invention aims to solve]

[0004] For example, oxide ions (O) within the crystal lattice are considered a major factor determining the reliability of multilayer ceramic electronic components at high voltages. 2- One method to ensure reliability is to reduce the concentration of defects as much as possible after sintering and to slow down the rate at which defects accumulate at the electrode interface when voltage is applied.

[0005] When using a metal less noble than hydrogen, such as nickel, as the metal for the internal electrode layer, a firing process in a reducing atmosphere is required to prevent oxidation of the electrode metal. However, in multilayer ceramic electronic components, for example, those primarily composed of barium titanate, a ferroelectric material, to ensure high capacity, a reducing atmosphere is necessary to prevent the oxidation of titanium ions (Ti). 4+ It is partially reduced to Ti 3+Oxide ion defects are generated to maintain the overall electrical neutrality of the oxide. Therefore, there are limits to reducing the concentration of oxide ion defects after sintering. Oxide ion defects are thought to move due to the internal electric field when a voltage is applied and eventually accumulate at the interface between the internal electrode layer and the dielectric layer. As this accumulation progresses, the electrical resistance at the interface is lost, and the electrical reliability of the entire multilayer ceramic electronic component is lost.

[0006] This invention has been made in view of the above problems, and aims to provide multilayer ceramic electronic components and dielectric ceramic compositions that can ensure reliability. [Means for solving the problem]

[0007] The multilayer ceramic electronic component according to the present invention has a plurality of dielectric particles comprising a first rare earth element selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, and a second rare earth element selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium, wherein the elemental ratio of the first rare earth element to the second rare earth element is 65:35 to 35:65, and comprises a dielectric layer having a segregated phase mainly composed of silicon oxide at the grain boundary triple points of the plurality of dielectric particles, a plurality of internal electrode layers facing each other with the dielectric layer in between, and an external electrode electrically connected to the plurality of internal electrode layers.

[0008] In the above-described multilayer ceramic electronic component, the segregation phase may be adjacent to 50% or more of the plurality of dielectric particles.

[0009] In the above-described multilayer ceramic electronic component, the average diameter of the segregated phase may be 10 nm or more.

[0010] In the dielectric particles of the multilayer ceramic electronic component described above, the content of the first rare earth element and the second rare earth element may be 1.5 mol% or more and 6.0 mol% or less.

[0011] In the above multilayer ceramic electronic component, the first rare earth element may be europium, and the second rare earth element may be yttrium.

[0012] In the above multilayer ceramic electronic component, the dielectric particles may mainly comprise a ceramic material having a perovskite structure.

[0013] In the above multilayer ceramic electronic component, the ceramic material may be barium titanate.

[0014] The porcelain composition according to the present invention has a plurality of dielectric particles containing at least one first rare earth element selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium and at least one second rare earth element selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, lutetium. The elemental number ratio between the first rare earth element and the second rare earth element is from 65:35 to 35:65, and the segregation phase mainly comprising silicon oxide is present at the grain boundary triple points of the plurality of dielectric particles.

Advantages of the Invention

[0015] According to the present invention, it is possible to provide a multilayer ceramic electronic component and a dielectric porcelain composition capable of ensuring reliability.

Brief Description of the Drawings

[0016] [Figure 1] It is a partial cross-sectional perspective view of a multilayer ceramic capacitor. [Figure 2] It is a cross-sectional view taken along line A-A of FIG. 1. [Figure 3] It is a cross-sectional view taken along line B-B of FIG. 1. [Figure 4] (a) and (b) are enlarged views near the external electrodes. [Figure 5] It is a schematic cross-sectional view of the dielectric layer. [Figure 6]It is an enlarged cross-sectional view around the dielectric particles. [Figure 7] It is a diagram illustrating the flow of a method for manufacturing a multilayer ceramic capacitor. [Figure 8] (a) and (b) are diagrams illustrating the printing process. [Figure 9] It is a diagram illustrating the crimping process. [Figure 10] It is a diagram tracing the BSE image of the sample of Example 1. [Figure 11] It is a diagram tracing the BSE image of the sample of Comparative Example 1. [Figure 12] It is a diagram tracing the BSE image of the sample of Comparative Example 2. [Figure 13] It is a diagram showing the results of the reliability test of Example 1. [Figure 14] It is a diagram showing the results of the reliability test of Comparative Example 1. [Figure 15] It is a diagram showing the results of the reliability test of Comparative Example 2.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments will be described while referring to the drawings.

[0018] (Embodiment) FIG. 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor 100 according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1. As illustrated in FIGS. 1 to 3, the multilayer ceramic capacitor 100 includes a body 10 having a substantially rectangular parallelepiped shape, and external electrodes 20a and 20b provided on two opposing end faces of the body 10. Among the four surfaces of the body 10 other than the two end faces, the two surfaces other than the upper and lower surfaces in the stacking direction are referred to as side surfaces. The external electrodes 20a and 20b extend to the upper surface, lower surface, and two side surfaces of the body 10 in the stacking direction. However, the external electrodes 20a and 20b are spaced apart from each other.

[0019] In Figures 1 to 3, the Z-axis direction (first direction) is the stacking direction, and is the direction in which each internal electrode layer faces another. The X-axis direction (second direction) is the length direction of the base body 10, and is the direction in which the two end faces of the base body 10 face each other, and is the direction in which the external electrode 20a and external electrode 20b face each other. The Y-axis direction (third direction) is the width direction of the internal electrode layer, and is the direction in which the two sides of the base body 10 (excluding the two end faces) face each other. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually orthogonal.

[0020] The base body 10 has a structure in which dielectric layers 11 containing a ceramic material (dielectric porcelain composition) that functions as a dielectric and internal electrode layers 12 are alternately stacked. The edges of each internal electrode layer 12 are alternately exposed to the end face of the base body 10 where the external electrode 20a is provided and the end face where the external electrode 20b is provided. As a result, each internal electrode layer 12 is alternately electrically connected to the external electrode 20a and the external electrode 20b. In the laminate of dielectric layers 11 and internal electrode layers 12, the inner electrode layer 12 is arranged as the outermost layer in the stacking direction, and the upper and lower surfaces of the laminate are covered by a cover layer 13. The cover layer 13 mainly consists of a ceramic material. For example, the composition of the cover layer 13 may be the same as or different from that of the dielectric layer 11. Note that the configuration is not limited to Figures 1 to 3, as long as the inner electrode layer 12 is exposed to two different surfaces and electrically connected to different external electrodes.

[0021] The dimensions of the multilayer ceramic capacitor 100 are, for example, 0.25 mm in length, 0.125 mm in width, and 0.125 mm in height, or 0.4 mm in length, 0.2 mm in width, and 0.2 mm in height, or 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height, or 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, or 3.2 mm in length, 1.6 mm in width, and 1.6 mm in height, or 4.5 mm in length, 3.2 mm in width, and 2.5 mm in height, but are not limited to these dimensions.

[0022] The internal electrode layer 12 is mainly composed of base metals such as nickel (Ni), copper (Cu), tin (Sn), or alloys containing these. As the internal electrode layer 12, noble metals such as platinum (Pt), palladium (Pd), silver (Ag), gold (Au), or alloys containing these may be used. The thickness of the internal electrode layer 12 is, for example, 5.0 μm or less, 3.0 μm or less, and 1.0 μm or less. The thickness of the internal electrode layer 12 can be measured by observing the cross-section of the multilayer ceramic capacitor 100 with a SEM (scanning electron microscope), measuring the thickness at 10 points each for 10 different internal electrode layers 12, and deriving the average value of all measurement points.

[0023] The dielectric layer 11 is mainly composed of, for example, a ceramic material having a perovskite structure represented by the general formula ABO3. Note that the perovskite structure contains ABO 3-α deviating from the stoichiometric composition. For example, as the ceramic material, at least one selected from barium titanate (BaTiO3), calcium zirconate (CaZrO3), calcium titanate (CaTiO3), strontium titanate (SrTiO3), magnesium titanate (MgTiO3), Ba 1-x-y Ca x Sr y Ti 1-z Zr z O3 (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ z ≤ 1), etc. can be selected and used. Ba 1-x-y Ca x Sr y Ti 1-z Zr zO3 includes barium strontium titanate, barium calcium titanate, barium zirconate, barium zirconate titanate, calcium zirconate titanate, and barium calcium zirconate titanate. For example, in the dielectric layer 11, the main component ceramic is present in an amount of 90 at% or more. The thickness of the dielectric layer 11 is, for example, 1 μm to 15 μm, 2 μm to 12 μm, and 3 μm to 10 μm. The thickness of the dielectric layer 11 can be measured by observing the cross-section of the multilayer ceramic capacitor 100 with an SEM (scanning electron microscope), measuring the thickness at 10 points for each of 10 different dielectric layers 11, and deriving the average value of all measurement points.

[0024] The dielectric layer 11 may contain additives. Examples of additives to the dielectric layer 11 include oxides of zirconium (Zr), hafnium (Hf), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), chromium (Cr), rare earth elements (yttrium (Y), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), and ytterbium (Yb)), or oxides containing cobalt (Co), nickel (Ni), lithium (Li), boron (B), sodium (Na), potassium (K), or silicon (Si), or glass containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon.

[0025] As illustrated in Figure 2, the region where the internal electrode layer 12 connected to the external electrode 20a and the internal electrode layer 12 connected to the external electrode 20b face each other is a region in the multilayer ceramic capacitor 100 where capacitance is generated. Therefore, this region where capacitance is generated is referred to as the capacitance section 14. In other words, the capacitance section 14 is a region where adjacent internal electrode layers 12 connected to different external electrodes face each other.

[0026] The region where internal electrode layers 12 connected to external electrode 20a face each other without being connected to an internal electrode layer 12 connected to external electrode 20b is called the end margin 15. Similarly, the region where internal electrode layers 12 connected to external electrode 20b face each other without being connected to an internal electrode layer 12 connected to external electrode 20a is also called the end margin 15. In other words, the end margin 15 is the region where internal electrode layers 12 connected to the same external electrode face each other without being connected to an internal electrode layer 12 connected to a different external electrode. The end margin 15 is a region where no capacitance is generated.

[0027] As illustrated in Figure 3, in the element 10, the side margin 16 is a region provided to cover the two side edges (the edges in the Y-axis direction) of the dielectric layer 11 and the internal electrode layer 12. In other words, the side margin 16 is a region provided outside the capacitance portion 14 in the Y-axis direction. The side margin 16 is also a region that does not generate capacitance.

[0028] In the YZ cross-section, the cover layer 13 and the side margins 16 form the outer periphery of the capacitance portion 14. Therefore, in the following, the portion forming the outer periphery of the capacitance portion 14 in the YZ cross-section may be collectively referred to as the outer periphery. The cover layer 13 refers to the portion of the outer periphery in the Y-axis direction that is above the uppermost internal electrode layer 12. Thus, the capacitance portion 14 and a pair of side margins are sandwiched between the two cover layers 13.

[0029] Figure 4(a) is an enlarged cross-sectional view near the external electrode 20a. Figure 4(b) is an enlarged cross-sectional view near the external electrode 20b. Hatches are omitted in Figures 4(a) and 4(b). As illustrated in Figures 4(a) and 4(b), the external electrodes 20a and 20b have a structure in which a plating layer 22 is provided on a base layer 21. The base layer 21 mainly consists of nickel, copper, etc. The base layer 21 may also contain ceramic particles as a co-material, or it may contain glass components. The plating layer 22 mainly consists of metals such as nickel, copper, aluminum, zinc, tin, or alloys of two or more of these. The plating layer 22 may be a plating layer of a single metal component, or it may be multiple plating layers of different metal components. For example, the plating layer 22 has a structure in which a first plating layer 23, a second plating layer 24, and a third plating layer 25 are formed in order from the base layer 21 side. The first plating layer 23 is, for example, a copper plating layer. The second plating layer 24 is, for example, a nickel plating layer. The third plating layer 25 is, for example, a tin plating layer.

[0030] Figure 5 is a schematic cross-sectional view of the dielectric layer 11. As illustrated in Figure 5, the dielectric layer 11 has a structure in which a plurality of dielectric particles 30 constituting the main phase are sintered. For example, the dielectric layer 11 may have one dielectric particle 30 in the thickness direction, or it may have a structure in which a plurality of dielectric particles 30 are continuous via grain boundaries, as shown in Figure 5.

[0031] Here, we consider the elements into which the dielectric particles 30 are solid-solved. Oxides with a perovskite structure, such as barium titanate, are characterized by having two types of sites in the crystal where cations exist. Sites occupied by +2 valence metal elements are called A sites, and sites occupied by +4 valence metal elements are called B sites. The ion size of A sites is relatively large. Therefore, A sites tend to be occupied mainly by ionic radii of 0.1 nm or more. B sites tend to be occupied by ionic ions with relatively small ion sizes. When the combined valence of the A site metal elements and B site metal elements is +6, an ideal perovskite oxide without defects is formed.

[0032] However, when a base metal is used in the internal electrode layer, some of the +4 valent metal elements become +3 valent during high-temperature reduction firing. Due to the 3d electrons of the +3 valent metal elements, high electrical conductivity is observed, and furthermore, the concentration of oxide ion defects (sometimes called oxygen defects) increases due to the requirement of electrical neutrality. Therefore, multilayer ceramic capacitors made using pure perovskite material may have low insulation after firing, poor reliability, and may not be suitable for practical use.

[0033] When rare earth elements are ionized, their valence is typically +3 unless treated in a special atmosphere. Furthermore, the size of rare earth element ions is smaller than that of +2 ions at site A, but larger than that of +4 ions at site B. Therefore, rare earth elements can occupy either site A or site B. When a rare earth element ion occupies site A, it becomes positively charged in excess of the charge of its original site, thus acting as a donor in terms of its electronic structure, and electrons are donated into the band structure. When a rare earth element ion occupies site B, its charge is insufficient compared to its original site, and it acts as an acceptor, electrons are recovered, and the oxide ion vacancy concentration increases.

[0034] Adding rare earth elements that tend to occupy only the A-site of the perovskite structure after reduction firing reduces the oxide ion defect concentration as donors but increases the electron concentration, leading to conductivity. If the rare earth element occupies only the B-site of the perovskite structure after reduction firing, the effect of electron donors can be offset, but the concentration of oxide ion defects increases further to compensate for the charge deficiency, which is unfavorable for reliability. However, if a single rare earth element that can occupy both the A-site and the B-site is added, both sites will be occupied simultaneously in a certain ratio during firing, and the donor and acceptor effects will cancel each other out, suppressing both the generation of oxide ion defects and the increase in electron concentration. For these reasons, it has been necessary to use only rare earth elements with an affinity for both the A-site and the B-site and a limited range of appropriate ion sizes as additives, aiming to reduce electron and oxide ion defects by occupying both sites and improving reliability.

[0035] However, in the case of adding a single rare earth element, the allocation of A and B sites as solid solution destinations is inevitably determined by the interplay of various additives other than the rare earth element and the firing conditions. Furthermore, it is possible that not all of the added rare earth elements react with the perovskite material and form a solid solution during firing. Perovskite materials used in multilayer ceramic capacitors often use additives other than rare earth elements, such as transition metals from the fourth period (vanadium to copper), transition metals from the fifth period (zirconium to silver), zinc, magnesium, aluminum, calcium, and strontium. In addition, silicon is added in the form of silicon oxide (SiO2) with the aim of forming a liquid phase during firing and contributing to improved sinterability. Of these additives, the fourth and fifth period transition metals, zinc, magnesium, aluminum, calcium, and strontium can be readily dissolved in perovskite materials after cationization. However, due to differences in chemical properties, silicon cannot be dissolved in perovskite-type oxide crystals. On the other hand, rare earth element silicates can be easily formed from rare earth elements and silicon oxide. Therefore, some of the added rare earth elements that could not be dissolved in the perovskite material during firing may remain as crystalline impurities in the perovskite phase in the form of rare earth element silicates after firing. Similarly, additives other than rare earth elements that do not dissolve in the perovskite will exist in the form of silicate crystals.

[0036] When adding rare earth elements, consider a method that consciously uses multiple types of rare earth elements, and always uses different types suitable for site A and site B of the perovskite material. Prepare rare earth elements with large ion sizes for site A, and rare earth elements with small ion sizes for site B. If the two types work together to form solid solutions at sites A and B respectively, they can efficiently form solid solutions in the perovskite material. Furthermore, the sum of the valencies of the two rare earth element ions is +6, and in perovskite-type oxide structures, the donor and acceptor effects are exactly canceled out, thus suppressing the generation of oxide ion defects and electron generation. When adding a single rare earth element, for example, depending on differences in firing temperature and atmosphere, there is room for variation in the occupancy ratio between site A and site B, and ideal solid solution at both sites may not always be achieved. However, by adding two types of rare earth elements with different site orientations, solid solution at both sites A and B can always be expected in the desired form, regardless of changes in firing conditions.

[0037] If all additives other than silicon dioxide react with the perovskite, the resulting structure after calcination will consist of a phase of oxide particles based on the perovskite and a phase composed almost entirely of silicon dioxide. The phase composed almost entirely of silicon dioxide is a segregated phase mainly composed of silicon dioxide, not a silicate of rare earth elements. For silicon dioxide to be the main component in the segregated phase means, for example, that the silicon dioxide content in the segregated phase is 50 mol% or more.

[0038] For example, assuming the B site of the perovskite material is 100 mol%, the amount of silicon dioxide added is about 2 mol% or less, and at most about 5 mol% or less. Therefore, in terms of volume, the perovskite-type oxide particles are overwhelmingly more numerous, and the segregated phase, which is mainly composed of silicon dioxide, is located outside the perovskite material particles, at the grain boundaries.

[0039] When comparing metal oxides and silicon oxide, although both contain oxygen atoms, their bonding patterns are significantly different. In metal oxides, oxygen is ionized into oxide ions (O₂).2- It is well known that these defects can diffuse, and in fact, certain metal oxides are used as ionic conductors. On the other hand, in silicon oxide, whether it is crystalline silicon oxide or when forming glass, oxygen and silicon form a strong covalent bond, and for oxygen to diffuse in the form of an ion, this strong covalent bond must be repeatedly broken and reformed. Therefore, the diffusion of oxide ions in silicon oxide is very slow and is almost never clearly observed.

[0040] As a result, when additives other than silicon dioxide are incorporated into the oxide lattice to form a perovskite phase, and only silicon dioxide remains at the grain boundaries on the outside of the oxide, the energy barrier when oxide ion defects diffuse across the grain boundaries increases, making it possible to suppress the migration rate of oxide ion defects in the material as a whole. Consequently, the rate of accumulation of oxide ion defects at the electrode-oxide interface when voltage is applied is slowed down, improving the reliability of multilayer ceramic capacitors.

[0041] Based on the above findings, the multilayer ceramic capacitor 100 according to this embodiment has a configuration that ensures reliability.

[0042] Figure 6 is an enlarged cross-sectional view of the area around the dielectric particles 30. As illustrated in Figure 6, a grain boundary triple point is formed by three or more dielectric particles 30. A grain boundary triple point is the boundary between three or more dielectric particles. A segregated phase 40, mainly composed of silicon oxide, is located at the grain boundary triple point.

[0043] The dielectric particles 30 include a first rare earth element with a large ionic radius and a second rare earth element with a smaller ionic radius than the first rare earth element. In this embodiment, at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium is used as the first rare earth element. At least one selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium is used as the second rare earth element.

[0044] Table 1 shows the ionic radii of each rare earth element in six coordination states. The source of Table 1 is "RDShannon, Acta Crystallogr., A32, 751 (1976)". [Table 1]

[0045] Through diligent research by the inventors, it has been discovered that when the dielectric particles 30 contain both the above-mentioned first rare earth element and second rare earth element, and the elemental ratio of the first rare earth element to the second rare earth element is 65:35 to 35:65, a characteristic structure is created at the grain boundaries of the dielectric particles 30. Furthermore, it has been found that the migration of oxide ions is suppressed when a segregated phase 40 mainly composed of silicon oxide is arranged at the triple junction of the grain boundaries of the dielectric particles 30. The reliability of the dielectric layer 11 is ensured by suppressing the migration of oxide ions. Here, if the dielectric particles 30 contain multiple types of first rare earth elements from among lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, the number of first rare earth elements is the total number of elements of the multiple types of first rare earth elements. In dielectric particles 30, if multiple types of secondary rare earth elements are included as secondary rare earth elements, the number of elements of the above secondary rare earth elements is the total number of elements of the multiple types of secondary rare earth elements.

[0046] The first rare earth element is not particularly limited as long as it is at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, and the second rare earth element is not particularly limited as long as it is at least one selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium, however, it is preferable to use europium as the first rare earth element and yttrium as the second rare earth element. The detailed mechanism is not fully understood, but it is thought that sintering and solid solution proceed particularly quickly when europium and yttrium are combined, and therefore a favorable effect is likely to be obtained when fired under the same conditions.

[0047] In dielectric particles 30, if the content of the first rare earth element is too low compared to the content of the second rare earth element, reliability may decrease. On the other hand, if the content of the first rare earth element is too high compared to the content of the second rare earth element, the insulating properties may be insufficient, making it unsuitable for use as a dielectric. In this embodiment, the elemental ratio of the first rare earth element to the second rare earth element is preferably 60:40 to 40:60, and more preferably 55:45 to 45:55.

[0048] If the total content of the first and second rare earth elements in the dielectric particles 30 is too low, there is a risk that they will not be able to adequately occupy the A and B sites of the perovskite material. Therefore, it is preferable to set a lower limit on the total content of the first and second rare earth elements in the dielectric particles 30. In this embodiment, the total content of the first and second rare earth elements in the dielectric particles 30 is preferably 1.5 mol% or more, more preferably 2.0 mol% or more, and even more preferably 3.0 mol% or more, when the B site metal element such as titanium is set to 100 mol%.

[0049] On the other hand, if the total content of the first rare earth element and the second rare earth element in the dielectric particles 30 is too high, there is a risk that the relative permittivity will decrease excessively to below 1,000. Therefore, it is preferable to set an upper limit on the total content of the first rare earth element and the second rare earth element in the dielectric particles 30. In this embodiment, the total content of the first rare earth element and the second rare earth element in the dielectric particles 30 is preferably 6.0 mol% or less, more preferably 5.0 mol% or less, and even more preferably 4.5 mol% or less, when the B-site metal element such as titanium is set to 100 mol%.

[0050] In the dielectric layer 11, if the amount of segregated phase 40 is too small, the movement of oxide ion defects may not be sufficiently suppressed. Therefore, it is preferable to set a lower limit on the amount of segregated phase 40 in the dielectric layer 11. In this embodiment, in a cross-section including the stacking direction of the dielectric layer 11, it is preferable that at least 50% of the dielectric particles 30 contained in the dielectric layer 11 are in contact with one of the segregated phases 40, more preferably at least 75% of the dielectric particles 30 are in contact with one of the segregated phases 40, and even more preferably at least 90% of the dielectric particles 30 are in contact with one of the segregated phases 40.

[0051] Furthermore, in a cross-section including the stacking direction of the dielectric layer 11, the area ratio of the segregation phase 40 is preferably 0.1% or more, more preferably 0.5% or more, and even more preferably 1.0% or more. The area ratio of the segregation phase 40 is determined by binarizing the SEM image and using the ratio of the total area of ​​the black portion to the total area of ​​the SEM image.

[0052] On the other hand, if there is too much segregated phase 40 in the dielectric layer 11, the relative permittivity of the sintered body as a whole may decrease, and it may not be able to function as a dielectric. Therefore, it is preferable to set an upper limit on the amount of segregated phase 40 in the dielectric layer 11. In this embodiment, in a cross-section including the stacking direction of the dielectric layer 11, the area ratio of the segregated phase 40 is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less.

[0053] If the segregated phase 40 is too small, the movement of oxide ions may not be sufficiently suppressed. Therefore, it is preferable to set a lower limit on the average diameter of the segregated phase 40. In this embodiment, the average diameter of the segregated phase 40 is preferably 10 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. The average diameter of the segregated phase 40 can be calculated by binarizing the SEM image, calculating the diameter of circles with an area equivalent to the area of ​​each black region, and averaging these diameters.

[0054] On the other hand, if the segregated phase 40 is too large, the dielectric constant of the sintered body as a whole may decrease, making it difficult to obtain its dielectric function. Therefore, it is preferable to set an upper limit on the average diameter of the segregated phase 40. In this embodiment, the average diameter of the segregated phase 40 is preferably 200 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less.

[0055] Next, the manufacturing method of the multilayer ceramic capacitor 100 will be described. Figure 7 is a diagram illustrating the flow of the manufacturing method of the multilayer ceramic capacitor 100.

[0056] (Process for producing raw material powder) First, a dielectric material for forming the dielectric layer 11, a cover material for forming the cover layer 13, and an inverse pattern material for forming the side margin 16 are prepared. The dielectric material, cover material, and inverse pattern material include barium titanate powder having a perovskite structure. For example, barium titanate is a tetragonal compound having a perovskite structure and exhibits a high dielectric constant. Barium titanate powder can generally be synthesized by reacting a titanium raw material such as titanium dioxide with a barium raw material such as barium carbonate. Various methods for synthesizing barium titanate powder are conventionally known, such as the solid-phase method, the sol-gel method, and the hydrothermal method. Any of these can be used in this embodiment.

[0057] The obtained barium titanate powder is then mixed with predetermined additive compounds according to the purpose to produce dielectric materials, cover materials, and reverse pattern materials, respectively. Examples of additive compounds include oxides of zirconium, hafnium, magnesium, manganese, molybdenum, vanadium, chromium, rare earth elements (yttrium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, and ytterbium), or oxides containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon, or glasses containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon. The addition of oxides of the first and second rare earth elements may be done at the same time, but it is preferable that the particle size of the raw material for the second rare earth element is the same as or smaller than the particle size of the raw material for the first rare earth element. Alternatively, complex raw materials can be used as rare earth raw materials. In that case, it is preferable to add the rare earth elements later than the other additives, and more preferably to add them last.

[0058] (Coating process) A dielectric material is wet-mixed with a binder such as polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer. Using the resulting slurry, a dielectric green sheet 51 is coated onto a substrate by, for example, a die coater or a doctor blade and then dried. The substrate is, for example, polyethylene terephthalate (PET) film.

[0059] (Printing process) Next, as illustrated in Figure 8(a), a metal conductive paste for forming internal electrodes containing an organic binder is printed on the surface of the dielectric green sheet 51 by screen printing, gravure printing, or the like, thereby arranging an internal electrode pattern 52 that is alternately drawn out to a pair of external electrodes with different polarities. Ceramic particles are added to the metal conductive paste as a co-material. The main component of the ceramic particles is not particularly limited, but it is preferable that it is the same as the main component ceramic of the dielectric layer 11. For example, barium titanate with an average particle diameter of 50 nm or less may be uniformly dispersed.

[0060] Next, an ethylcellulose-based binder and an organic solvent such as terpineol-based solvent are added to the reverse pattern material and kneaded in a roll mill to obtain a reverse pattern paste. As illustrated in Figure 8(a), the reverse pattern 53 is placed on the dielectric green sheet 51 by printing the reverse pattern paste in the peripheral area where the internal electrode pattern 52 is not printed, thereby filling the step between it and the internal electrode pattern 52. The dielectric green sheet 51 with the internal electrode pattern 52 and the reverse pattern 53 printed on it is called a laminated unit.

[0061] Subsequently, as illustrated in Figure 8(b), stacking units are carried out so that the internal electrode layer 12 and the dielectric layer 11 are staggered, and the edges of the internal electrode layer 12 are alternately exposed on both ends of the dielectric layer 11 in the longitudinal direction, alternately leading to a pair of external electrodes 20a and 20b with different polarities. For example, the number of stacked internal electrode patterns 52 is set to 100 to 1000 layers.

[0062] (Crimping process) Next, an ethylcellulose-based binder and an organic solvent such as terpineol-based solvent are added to the cover material and kneaded in a roll mill to obtain a cover sheet 54. As illustrated in Figure 9, a predetermined number of cover sheets 54 are laminated on the top and bottom of a laminate in which laminated units are stacked and then heat-pressed together. After that, they are cut to predetermined chip dimensions (for example, 1.0 mm x 0.5 mm).

[0063] (Coating process) The ceramic laminate obtained in this way is subjected to a binder removal treatment in an N2 atmosphere, an air atmosphere, etc., and then a metal paste, which will serve as the base layer for the external electrodes 20a and 20b, is applied by a dipping method.

[0064] (Firing process) Subsequently, the mixture is heated in a reducing atmosphere using a N2-H2-H2O mixed gas at a rate of 100°C / h to 300°C / h from 700°C to 1000°C, and held for 1 to 4 hours to remove the binder. Then, the heating rate is increased to 100°C / h to 400°C / h, and the temperature is raised to 1100°C to 1300°C, held for 0.1 to 4 hours for firing, and then the temperature is lowered to room temperature. The atmosphere during firing can be the same as that used for binder removal, but increasing the H2 ratio compared to the binder removal stage will promote sintering and allow for the formation of more segregation.

[0065] (Re-oxidation process) Subsequently, a re-oxidation treatment may be performed in an N2 gas atmosphere at 600°C to 1000°C.

[0066] (Plating process) Subsequently, a metal coating of Cu, Ni, Sn, etc. is applied to the underlayer of the external electrodes 20a and 20b by plating. Through these steps, the multilayer ceramic capacitor 100 is completed.

[0067] In the embodiments described above, multilayer ceramic capacitors were explained as examples of multilayer ceramic electronic components, but the invention is not limited to them. For example, other multilayer ceramic electronic components such as varistors and thermistors may be used. [Examples]

[0068] Below, a multilayer ceramic capacitor according to the embodiment was fabricated and its characteristics were investigated.

[0069] (Example 1) Barium titanate, prepared by solid-phase synthesis, was used as the base for 100 mol%, and europium was weighed to 1.8 mol% (0.9 mol% in the form of Eu2O3), yttrium to 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Magnesium, vanadium, manganese, and zirconium were added as additives. This mixed powder was dispersed in zirconia beads with ethanol, toluene, and a dispersant. After dispersion, the slurry was filtered to separate it from the zirconia beads, and then PVB (polyvinyl butyral) resin was mixed as a binder to obtain the slurry. Therefore, in Example 1, the elemental ratio of the first rare earth element to the second rare earth element was 50:50.

[0070] The slurry obtained in this way was coated onto a PET film using a die coater to form a dielectric green sheet with a thickness of 0.5 μm. After drying this dielectric green sheet, nickel paste was printed to form the internal electrode pattern. The dielectric green sheets with the printed internal electrode pattern were laminated. At this time, the positive electrode pattern and negative electrode pattern were laminated alternately. Dielectric layers of the same composition, each 50 μm thick, were stacked above and below as protective layers and heat-pressed. After sintering the plate-shaped molded body thus produced, it was cut into individual pieces (chips) with dimensions of 1.0 mm × 0.5 mm. After cutting, nickel paste was dipped into the two opposing surfaces of the chips where the internal electrode lead-out portions were exposed to form terminal electrodes.

[0071] The prepared chips were heated to 800°C at a rate of 100°C / h in a reducing atmosphere using a mixed gas of N2-H2-H2O, held for 2 hours, and then the binder was removed. After that, the heating rate was increased to 200°C / h, the temperature was raised to 1250°C and held for 2 hours, and then the temperature was lowered to room temperature. The sintered chips were then re-oxidized at 800°C in a dry N2 atmosphere. A multilayer ceramic capacitor was thus obtained.

[0072] (Comparative Example 1) In Comparative Example 1, barium titanate prepared by solid-phase synthesis was used as the base amount (100 mol%), and europium was weighed to 3.6 mol% (1.8 mol% in the form of Eu2O3) and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Yttrium was not used. All other conditions were the same as in Example 1.

[0073] (Comparative Example 2) In Comparative Example 2, barium titanate prepared by solid-phase synthesis was used as the base amount (100 mol%), and yttrium was weighed to a concentration of 3.6 mol% (1.8 mol%) in the form of Y2O3, and silicon to a concentration of 1.0 mol% (1.0 mol%) in the form of SiO2. Europium was not used. All other conditions were the same as in Example 1.

[0074] (Presence or absence of segregation phase) BSE images (backscattered electron images) of the cross-section of the dielectric layer were obtained for each sample in Example 1 and Comparative Examples 1 and 2. Figure 10 is a traced BSE image of the sample from Example 1. Figure 11 is a traced BSE image of the sample from Comparative Example 1. Figure 12 is a traced BSE image of the sample from Comparative Example 2.

[0075] As shown in Figure 10, in the sample of Example 1, a segregated phase 40 (the black area in Figure 10) mainly composed of silicon oxide was observed at the triple point of the dielectric particles of the main phase. This is thought to be because europium was used as the first rare earth element and yttrium as the second rare earth element, and the elemental ratio of the first and second rare earth elements was set to 50:50. In contrast, no segregated phase mainly composed of silicon oxide was observed in the samples of Comparative Examples 1 and 2. This is thought to be because only one of the first or second rare earth elements was used.

[0076] (Reliability testing) Next, reliability tests were performed on 10 samples each for Example 1 and Comparative Examples 1 and 2. In the reliability tests, the behavior leading to dielectric breakdown was investigated when a voltage of 50V per μm was continuously applied at a temperature of 150°C. Figure 13 shows the results for Example 1, Figure 14 shows the results for Comparative Example 1, and Figure 15 shows the results for Comparative Example 2. In all of Figures 13 to 15, the horizontal axis represents elapsed time (minutes), and the vertical axis represents current (μA).

[0077] If the average lifespan was 1,000 minutes or more, the reliability test was judged as a pass ("○"), otherwise it was judged as a fail ("×").

[0078] As shown in Figure 13, in Example 1, the time to dielectric breakdown was approximately 10,000 minutes on average and 19,000 minutes at its longest. Therefore, Example 1 was judged to have passed the reliability test ("○"). This is a surprising result, indicating that sufficient reliability was obtained in Example 1. This is thought to be because the segregated phase, mainly composed of silicon oxide, was positioned at the triple point of the dielectric particles, thereby suppressing the movement of oxide ions.

[0079] In contrast, as shown in Figure 14, the average time to dielectric breakdown in Comparative Example 1 was approximately 600 minutes, with a maximum of approximately 900 minutes. Also, as shown in Figure 15, the average time to dielectric breakdown in Comparative Example 2 was approximately 300 minutes, with a maximum of 500 minutes. Therefore, Comparative Examples 1 and 2 were judged to have failed the reliability test ("×"). From these results, it can be concluded that in Comparative Examples 1 and 2, the segregated phase mainly composed of silicon dioxide did not segregate, and thus the movement of oxide ions was not suppressed. These results are shown in Table 2. [Table 2]

[0080] (Example 2) In Example 2, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 2.34 mol% (1.17 mol% in the form of Gd2O3), yttrium to 1.26 mol% (0.63 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 65:35. All other conditions were the same as in Example 1.

[0081] (Example 3) In Example 3, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 1.8 mol% (0.9 mol% in the form of Gd2O3), yttrium to 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0082] (Example 4) In Example 4, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 1.26 mol% (0.63 mol% in the form of Gd2O3), yttrium to 2.34 mol% (1.17 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 35:65. All other conditions were the same as in Example 1.

[0083] (Example 5) In Example 5, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: europium 2.34 mol% (1.17 mol% in the form of Eu2O3), yttrium 1.26 mol% (0.63 mol% in the form of Y2O3), and silicon 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 65:35. All other conditions were the same as in Example 1.

[0084] (Example 6) In Example 6, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: europium 1.26 mol% (0.63 mol% in the form of Eu2O3), yttrium 2.34 mol% (1.17 mol% in the form of Y2O3), and silicon 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 35:65. All other conditions were the same as in Example 1.

[0085] (Example 7) In Example 7, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and lanthanum was weighed to 1.8 mol% (0.9 mol% in the form of La2O3), yttrium to 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0086] (Example 8) In Example 8, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and neodymium was weighed to 1.8 mol% (0.9 mol% in the form of Nd2O3), yttrium to 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0087] (Example 9) In Example 9, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 1.8 mol% (0.9 mol% in the form of Gd2O3), scandium to 1.8 mol% (0.9 mol% in the form of Sc2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0088] (Example 10) In Example 10, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: europium 1.8 mol% (0.9 mol% in the form of Eu2O3), scandium 1.8 mol% (0.9 mol% in the form of Sc2O3), and silicon 1.0 mol% (1.0 mol% in the form of SiO2). Thus, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0089] (Example 11) In Example 11, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 1.8 mol% (0.9 mol% in the form of Gd2O3), holmium to 1.8 mol% (0.9 mol% in the form of Ho2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0090] (Example 12) In Example 12, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to 1.8 mol% (0.9 mol% in the form of Gd2O3), holmium to 1.8 mol% (0.9 mol% in the form of Ho2O3), and silicon to 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 40:60. All other conditions were the same as in Example 1.

[0091] (Example 13) In Example 13, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: gadolinium at 1.8 mol% (0.9 mol% in the form of Gd2O3), ytterbium at 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon at 1.0 mol% (1.0 mol% in the form of SiO2). Thus, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0092] (Comparative Example 3) In Comparative Example 3, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: terbium 1.8 mol% (0.9 mol% in the form of Tb2O3), ytterbium 1.8 mol% (0.9 mol% in the form of Y2O3), and silicon 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0093] (Comparative Example 4) In Comparative Example 4, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: 1.8 mol% dysprosium (0.9 mol% in the form of Dy2O3), 1.8 mol% ytterbium (0.9 mol% in the form of Y2O3), and 1.8 mol% silicon (1.8 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0094] (Comparative Example 5) In Comparative Example 5, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: 1.8 mol% dysprosium (0.9 mol% in the form of Dy2O3), 1.8 mol% holmium (0.9 mol% in the form of Ho2O3), and 1.0 mol% silicon (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0095] (Comparative Example 6) In Comparative Example 6, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and the following elements were weighed out: gadolinium 1.8 mol% (0.9 mol% in the form of Gd2O3), dysprosium 1.8 mol% (0.9 mol% in the form of Dy2O3), and silicon 1.0 mol% (1.0 mol% in the form of SiO2). Therefore, the elemental ratio of the first rare earth element to the second rare earth element was 50:50. All other conditions were the same as in Example 1.

[0096] (Comparative Example 7) In Comparative Example 7, barium titanate prepared by solid-phase synthesis was used as the base amount (100 mol%), and neodymium was weighed to a total of 3.6 mol% (1.8 mol%) in the form of Nd2O3, and silicon to a total of 1.0 mol% (1.0 mol%) in the form of SiO2. No second rare earth elements were used. All other conditions were the same as in Example 1.

[0097] (Comparative Example 8) In Comparative Example 8, barium titanate prepared by solid-phase synthesis was used as 100 mol%, and gadolinium was weighed to a total of 3.6 mol% (1.8 mol% in the form of Gd2O3) and silicon to a total of 1.0 mol% (1.0 mol% in the form of SiO2). No second rare earth elements were used. All other conditions were the same as in Example 1.

[0098] (Presence or absence of segregation phase) For each sample in Examples 2-13 and Comparative Examples 3-8, BSE images (backscattered electron images) of the cross-section of the dielectric layer were obtained to confirm the presence or absence of the segregation phase 40. In all of Examples 2-13, the segregation phase 40, mainly composed of silicon oxide, was confirmed at the triple point of the dielectric particles of the main phase. This is thought to be because one of the following was used as the first rare earth element: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, or gadolinium, and one of the following was used as the second rare earth element: yttrium, scandium, holmium, erbium, thulium, ytterbium, or lutetium, and the elemental ratio of the first and second rare earth elements was set to 65:35 or 35:65.

[0099] In contrast, no segregated phase mainly composed of silicon dioxide was observed in the samples of Comparative Examples 3 to 8. This is thought to be because terbium was used as the first rare earth element in Comparative Example 3, dysprosium was used as the first rare earth element in Comparative Examples 4 and 5, dysprosium was used as the second rare earth element in Comparative Example 6, and only the first rare earth element was used in Comparative Examples 7 and 8.

[0100] (Reliability testing) Next, similar to Example 1, reliability tests were performed on 10 samples for each of Examples 2-13 and Comparative Examples 3-8. The average lifetime until dielectric breakdown was 4,500 minutes for Example 2, 10,000 minutes for Example 3, 5,500 minutes for Example 4, 5,500 minutes for Example 5, 7,500 minutes for Example 6, 1,100 minutes for Example 7, 1,800 minutes for Example 8, 1,200 minutes for Example 9, 1,300 minutes for Example 10, 4,500 minutes for Example 11, 2,800 minutes for Example 12, 1,300 minutes for Example 13, 300 minutes for Comparative Example 3, 600 minutes for Comparative Example 4, 800 minutes for Comparative Example 5, 0 minutes for Comparative Example 6, 0 minutes for Comparative Example 7, and 0 minutes for Comparative Example 8.

[0101] Therefore, all of Examples 2 to 13 passed the reliability test and were judged as "passing" (○). This is a surprising result, indicating that sufficient reliability was obtained in Examples 2 to 13. This is thought to be because the segregated phase, mainly composed of silicon dioxide, was positioned at the triple point of the dielectric particles, thereby suppressing the movement of oxide ions.

[0102] In contrast, comparative examples 2-8 failed the reliability test ("×"). These results suggest that in comparative examples 2-8, the segregated phase, mainly composed of silicon dioxide, did not segregate, thus preventing the suppression of oxide ion movement. These results are shown in Table 3. [Table 3]

[0103] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0104] 10 Base Body 11 Dielectric layer 12 Internal electrode layer 13. Cover layer 14 Capacity part 15 End margin 16 Side margins 20a,20b external electrode 30 Dielectric Particles 40 Segregated phase 51 Dielectric Green Sheet 52 Internal electrode patterns 53 Reverse Pattern 54 Cover Sheets 100 Multilayer Ceramic Capacitors

Claims

1. A dielectric layer comprising a plurality of dielectric particles comprising a first rare earth element selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, and a second rare earth element selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium, wherein the elemental ratio of the first rare earth element to the second rare earth element is 65:35 to 35:65, and the dielectric layer having a segregated phase mainly composed of silicon oxide at the grain boundary triple points of the plurality of dielectric particles, Multiple internal electrode layers facing each other with the dielectric layer in between, A multilayer ceramic electronic component having an external electrode electrically connected to a plurality of internal electrode layers.

2. The multilayer ceramic electronic component according to claim 1, wherein the segregated phase is adjacent to 50% or more of the plurality of dielectric particles.

3. The multilayer ceramic electronic component according to claim 1, wherein the average diameter of the segregated phase is 10 nm or more.

4. The multilayer ceramic electronic component according to claim 1, wherein the content of the first rare earth element and the second rare earth element in the dielectric particles is 1.5 mol% or more and 6.0 mol% or less.

5. The multilayer ceramic electronic component according to claim 1, wherein the first rare earth element is europium and the second rare earth element is yttrium.

6. The multilayer ceramic electronic component according to claim 1, wherein the dielectric particles mainly consist of a ceramic material having a perovskite structure.

7. The multilayer ceramic electronic component according to claim 6, wherein the ceramic material is barium titanate.

8. A dielectric ceramic composition comprising a plurality of dielectric particles comprising a first rare earth element selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, and gadolinium, and a second rare earth element selected from yttrium, scandium, holmium, erbium, thulium, ytterbium, and lutetium, wherein the elemental ratio of the first rare earth element to the second rare earth element is 65:35 to 35:65, and the plurality of dielectric particles have a segregated phase mainly composed of silicon oxide at the grain boundary triple points.

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