Dielectric composition, multilayer ceramic electronic component, manufacturing method of dielectric composition, and manufacturing method of multilayer ceramic electronic component

Abstract

To provide a dielectric composition, a multilayer ceramic electronic component, a manufacturing method of a dielectric composition, and a manufacturing method of a multilayer ceramic electronic component, capable of achieving both a long life and the excellent temperature characteristics of capacity.SOLUTION: A dielectric composition includes: a main component containing barium titanate; a first additive containing zirconium in an amount of 2 at% or more and 10 at% or less with respect to titanium of the barium titanate; a second additive containing 0.2 at% or more and 3.5 at% or less of europium with respect to titanium of the barium titanate, and a content of a rear earth element other than the europium is less than that of the europium; a third additive containing 0.5 at% or more and 4.5 at% or less of manganese with respect to titanium of the barium titanate; and a fourth additive containing at least one of strontium and calcium in an amount of 0.1 at% or more and 3 at% or less with respect to titanium in the barium titanate.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a dielectric composition, a multilayer ceramic electronic component, a method for manufacturing a dielectric composition, and a method for manufacturing a multilayer ceramic electronic component.

Background Art

[0002] In high-frequency communication systems typified by mobile phones, multilayer ceramic capacitors are used to remove noise. Also, multilayer ceramic capacitors are used in electronic circuits related to human life, such as in-vehicle electronic control devices. Since high reliability is required for multilayer ceramic capacitors, techniques for improving reliability have been disclosed (for example, see Patent Documents 1 to 5).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] For the dielectric of multilayer ceramic capacitors, sintered bodies with a core-shell structure have been used, where barium titanate forms the core and a shell containing various additives in solid solution surrounds the core. This is because it allows for the acquisition of a material with excellent capacitance-temperature characteristics and a stable microstructure even during the firing process. Magnesium (Mg) is a typical additive that constitutes the shell. However, magnesium is a simple acceptor that does not undergo valence fluctuations and generates oxygen vacancies, which are known to negatively affect the reliability of multilayer ceramic capacitors under electrical neutral conditions. Therefore, there has been a problem in that the reliability cannot be sufficiently high for high-reliability applications.

[0005] Next, for high-reliability applications, multilayer ceramic capacitors that can be used at high temperatures up to 150°C are required. However, barium titanate, the main component of the dielectric layer, has a Curie point of approximately 125°C, and its capacitance decreases significantly above the Curie point. Therefore, without special measures, it is not possible to satisfy the EIA standard temperature characteristic X8R (capacitance change rate from -55°C to 150°C within ±15% of the 25°C capacitance). One improvement method is to add ytterbium (Yb) to the dielectric layer to shift the Curie point to the higher temperature side and satisfy X8R. However, since ytterbium acts as an acceptor, it does not provide sufficient reliability for high-reliability applications, similar to magnesium mentioned above. Another method involves mixing BaTi2O5 (470°C), which has a high Curie point, with BaTiO3. However, BaTi2O5 has a low dielectric constant at room temperature and cannot exhibit high capacitance.

[0006] The present invention has been made in view of the above problems, and aims to provide a dielectric composition, a multilayer ceramic electronic component, a method for manufacturing the dielectric composition, and a method for manufacturing the multilayer ceramic electronic component that can achieve both a long lifespan and excellent capacitance-temperature characteristics. [Means for solving the problem]

[0007] The dielectric composition according to the present invention comprises a main component containing barium titanate, a first additive containing zirconium in an amount of 2 at% to 10 at% relative to the titanium of the barium titanate, a second additive containing europium in an amount of 0.2 at% to 3.5 at% relative to the titanium of the barium titanate, with other rare earth elements being less abundant than europium, a third additive containing manganese in an amount of 0.5 at% to 4.5 at% relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium or calcium in an amount of 0.1 at% to 3 at% relative to the titanium of the barium titanate.

[0008] The dielectric composition described above may include a dielectric crystal having a core portion in which europium is solid-solved, and a shell portion covering the core portion, the shell portion having a higher zirconium concentration than the core portion.

[0009] In the dielectric composition described above, the second additive comprises divalent europium and trivalent europium, and the divalent europium may constitute 21% to 80% of the total europium contained in the second additive.

[0010] In the dielectric composition described above, the first additive may contain zirconium in an amount of 2 at% to 8 at% relative to the titanium of the barium titanate.

[0011] In the dielectric composition described above, the second additive may contain europium in an amount of 0.5 at% to 3 at% relative to the titanium of the barium titanate.

[0012] In the dielectric composition described above, the third additive may contain manganese in an amount of 0.5 at% to 3 at% relative to the titanium of the barium titanate.

[0013] In the dielectric composition described above, the fourth additive may contain at least one of strontium or calcium in an amount of 0.1 at% to 1 at% relative to the titanium of the barium titanate.

[0014] The multilayer ceramic electronic component according to the present invention comprises a plurality of dielectric layers comprising: a main component containing barium titanate; a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate; a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, with less rare earth elements other than europium; a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate; and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, with 0.1 at% to 3 at%; a plurality of internal electrode layers laminated through each of the plurality of dielectric layers; and external electrodes electrically connected to the plurality of internal electrodes.

[0015] In the above-described multilayer ceramic electronic component, the plurality of dielectric layers may include a dielectric crystal having a core portion in which europium is solid-solved and a shell portion that covers the core portion and has a higher zirconium concentration than the core portion.

[0016] In the above-described multilayer ceramic electronic component, the second additive comprises divalent europium and trivalent europium, and the divalent europium may constitute 21% to 80% of the total europium contained in the second additive.

[0017] In the above-described multilayer ceramic electronic component, the first additive may contain zirconium in an amount of 2 at% to 8 at% relative to the titanium of the barium titanate.

[0018] In the above-described multilayer ceramic electronic component, the second additive may contain europium in an amount of 0.5 at% to 3 at% relative to the titanium of the barium titanate.

[0019] In the above-mentioned multilayer ceramic electronic component, the third additive may contain manganese in an amount of 0.5 at% to 3 at% relative to the titanium of the barium titanate.

[0020] In the above multilayer ceramic electronic component, the fourth additive may contain at least one of strontium or calcium in an amount of 0.1 at% or more and 1 at% or less based on titanium in the barium titanate.

[0021] The above multilayer ceramic electronic component may satisfy the X8R characteristic.

[0022] The method for manufacturing a dielectric composition according to the present invention includes a step of forming a ceramic green sheet containing a main component containing barium titanate, a first additive containing zirconium in an amount of 2 at% or more and 10 at% or less based on titanium in the barium titanate, a second additive containing europium in an amount of 0.2 at% or more and 3.5 at% or less based on titanium in the barium titanate and having less rare earth elements other than europium than europium, a third additive containing manganese in an amount of 0.5 at% or more and 4.5 at% or less based on titanium in the barium titanate, and a fourth additive containing at least one of strontium or calcium in an amount of 0.1 at% or more and 3 at% or less based on titanium in the barium titanate, and a step of firing the ceramic green sheet at a heating rate of 5000 °C / h or more and 10000 °C / h or less.

[0023] A method for manufacturing a multilayer ceramic electronic component according to the present invention includes a coating step of forming a ceramic green sheet comprising: a main component containing barium titanate; a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate; a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, with less rare earth elements other than europium; a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate; and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, with 0.1 at% to 3 at%; an internal electrode formation step of forming an internal electrode pattern on the ceramic green sheet; a compression step of laminating the ceramic green sheets on which the internal electrode pattern has been formed; and a firing step of firing the laminated ceramic green sheets at a heating rate of 5000°C / h to 10000°C / h to form a plurality of dielectric layers and a plurality of internal electrodes.

[0024] The above-described method for manufacturing multilayer ceramic electronic components may further include a re-oxidation step in which the plurality of dielectric layers and the plurality of internal electrodes are heat-treated after the firing step. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a dielectric composition that can achieve both a long lifespan and excellent capacitance-temperature characteristics, a multilayer ceramic electronic component, a method for manufacturing the dielectric composition, and a method for manufacturing the multilayer ceramic electronic component. [Brief explanation of the drawing]

[0026] [Figure 1] This is a partial cross-sectional perspective view of a multilayer ceramic capacitor. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a cross-sectional view along line BB in Figure 1. [Figure 4](a) is a diagram illustrating core-shell particles, and (b) is a schematic cross-sectional view of the dielectric layer. [Figure 5] This diagram illustrates a flow chart of the manufacturing process for multilayer ceramic capacitors. [Figure 6] This is a schematic diagram of the SEM image of the stacked dielectric layer and internal electrode layer in the capacitance region for Example 1. [Figure 7] This is a schematic diagram of a TEM image of a dielectric layer in the capacitance region. [Figure 8] (a) shows the measurement results of TEM-EDS analysis on the shell portion, and (b) shows the measurement results of TEM-EDS analysis on the core portion. [Figure 9] This is a schematic diagram of the SEM image of the stacked dielectric layer and internal electrode layer in the capacitance region for Comparative Example 11. [Modes for carrying out the invention]

[0027] The embodiments will be described below with reference to the drawings.

[0028] (Embodiment) Figure 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor 100 according to an embodiment. Figure 2 is a cross-sectional view taken along line AA in Figure 1. Figure 3 is a cross-sectional view taken along line BB in Figure 1. As illustrated in Figures 1 to 3, the multilayer ceramic capacitor 100 comprises a multilayer chip 10 having a substantially rectangular parallelepiped shape and external electrodes 20a and 20b provided on two opposing end faces of either of the multilayer chips 10. Of the four faces of the multilayer chip 10 other than the two end faces, the two faces other than the top and bottom faces in the stacking direction are referred to as side faces. The external electrodes 20a and 20b extend to the top, bottom, and two side faces of the multilayer chip 10 in the stacking direction. However, the external electrodes 20a and 20b are spaced apart from each other.

[0029] The multilayer chip 10 has a structure in which dielectric layers 11 containing a ceramic material that functions as a dielectric and internal electrode layers 12 containing a base metal material are alternately stacked. The edges of each internal electrode layer 12 are alternately exposed to the end face of the multilayer chip 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. Consequently, the multilayer ceramic capacitor 100 has a structure in which multiple dielectric layers 11 are stacked via internal electrode layers 12. Furthermore, in the laminate of dielectric layers 11 and internal electrode layers 12, the outermost layer in the stacking direction is an internal electrode layer 12, and the top and bottom surfaces of the laminate are covered by a cover layer 13. The cover layer 13 mainly consists of a ceramic material. For example, the cover layer 13 may have the same composition as the dielectric layer 11 or a different composition. Furthermore, the configuration is not limited to that shown in Figures 1 to 3, as long as the internal electrode layer 12 is exposed on two different surfaces and is electrically connected to different external electrodes.

[0030] 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.

[0031] The internal electrode layer 12 mainly consists of base metals such as Ni (nickel), Cu (copper), and Sn (tin). Precious metals such as Pt (platinum), Pd (palladium), Ag (silver), and Au (gold), or alloys containing these, may also be used as the internal electrode layer 12. The thickness of the internal electrode layer 12 is, for example, 0.1 μm to 3 μm, 0.1 μm to 1 μm, or 0.1 μm to 0.5 μm.

[0032] The dielectric layer 11 is a dielectric composition, mainly composed of a ceramic material having a perovskite structure represented by the general formula ABO3. Note that this perovskite structure is an ABO3 structure that deviates from the stoichiometric composition. 3-α This includes the following. In this embodiment, barium titanate (BaTiO3) is used as the ceramic material. The thickness of the dielectric layer 11 is, for example, 0.2 μm to 10 μm, 0.2 μm to 5 μm, or 0.2 μm to 2 μm.

[0033] 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 region 14. In other words, the capacitance region 14 is the region where adjacent internal electrode layers 12 connected to different external electrodes face each other.

[0034] 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.

[0035] As illustrated in Figure 3, in the stacked chip 10, the region extending from the two sides of the stacked chip 10 to the internal electrode layer 12 is called the side margin 16. That is, the side margin 16 is a region provided to cover the ends of the multiple internal electrode layers 12 stacked in the stacked structure that extend to the two sides. The side margin 16 is also a region that does not generate electrical capacitance.

[0036] The dielectric layer 11 in the capacitance region 14 mainly consists of barium titanate and includes a first additive containing zirconium (Zr), a second additive containing europium (Eu), a third additive containing manganese (Mn), and a fourth additive containing at least one of strontium or calcium.

[0037] In the capacitance region 14 of such a multilayer ceramic capacitor 100, if at least a portion of the barium titanate crystal particles (dielectric crystals) contained in the dielectric layer 11 have a core-shell structure, the dielectric layer 11 in the capacitance region 14 will have a high dielectric constant, excellent temperature characteristics, and a stable microstructure will coexist.

[0038] Magnesium is a typical additive that makes up the shell. However, magnesium is a simple acceptor whose valency does not change, and it dissolves in the barium titanate of the dielectric layer 11, creating oxygen vacancies, which may limit its reliability.

[0039] (Regarding the first additive) Therefore, in this embodiment, the dielectric layer 11 of the capacitance region 14 contains the first additive, so that at least a portion of the barium titanate crystal grains contained in the dielectric layer 11 has a core-shell structure in which barium titanate forms the main component of the core and zirconium (Zr) diffusion layer forms the shell. The shell is mainly composed of barium titanate.

[0040] As illustrated in Figure 4(a), the core-shell particle 30 comprises a roughly spherical core portion 31 and a shell portion 32 that surrounds and covers the core portion 31. The core portion 31 is a crystalline portion in which the added compound is not solid-dissolved or the amount of added compound solid-dissolved is small. The shell portion 32 is a crystalline portion in which the added compound is solid-dissolved and has a higher concentration of the added compound than the concentration of the added compound in the core portion 31. In this embodiment, the zirconium concentration in the shell portion 32 is higher than the zirconium concentration in the core portion 31. Alternatively, zirconium is diffused in the shell portion 32, but not in the core portion 31.

[0041] Figure 4(b) is a schematic cross-sectional view of the dielectric layer 11. As illustrated in Figure 4(b), the dielectric layer 11 comprises multiple crystalline particles 17 of the main component ceramic. At least a portion of these crystalline particles 17 are the core-shell particles 30 described in Figure 4(a). By covering the core portion 31 with a shell portion 32 that has a high zirconium concentration and high reduction resistance, a material with a stable structure and high reliability can be obtained while maintaining a high dielectric constant.

[0042] Furthermore, if zirconium diffuses and solid-dissolves in barium titanate, it lowers the Curie temperature of barium titanate. Therefore, if the zirconium diffusion layer is made thicker than necessary, the capacitance change rate at high temperatures will increase, and the multilayer ceramic capacitor 100 may fail to meet the X8R characteristics. Generally, zirconium undergoes solid-solution diffusion in barium titanate, leading to rapid grain growth. Therefore, it is difficult to suppress grain growth by limiting the thickness of the diffusion layer to achieve X8R characteristics. For example, if the heating rate in the firing process is set to about 10°C / h, the diffusion of rare earth elements is excessively promoted, and all solid-solution particles are formed. In this case, solid solution of zirconium and rare earth elements progresses, resulting in a long lifespan, but the dielectric constant is low, sintering stability decreases, and the capacitance temperature characteristics tend to worsen. In this embodiment, the zirconium diffusion distance is limited, and the zirconium concentration in the shell portion 32 is higher than in the core portion 31, so the multilayer ceramic capacitor 100 meets the X8R characteristics.

[0043] In the dielectric layer 11 of the capacitance region 14, if the amount of zirconium is small, it may not be possible to maintain a core-shell structure having a core portion with a low zirconium concentration and a shell portion with a high zirconium concentration, leading to localized abnormal growth, which may result in a short lifespan and failure to obtain X8R characteristics. Therefore, in this embodiment, a lower limit is set on the amount of zirconium relative to titanium in barium titanate, which is the main component of the dielectric layer 11 (the amount of zirconium (at%) when titanium is set to 100 at%). Specifically, the amount of zirconium relative to titanium is set to 2 at% or more. In this case, the particle size of the crystal grains 17 becomes almost uniform, and a stable core-shell structure with an elemental distribution in which a high concentration of Zr is arranged in the shell portion 32 can be formed. The amount of zirconium relative to titanium is preferably 2 at% or more, and more preferably 4 at% or more.

[0044] On the other hand, if the amount of zirconium in the dielectric layer 11 in the capacitance region 14 is large, the relative permittivity of the dielectric layer 11 will become low (for example, 1500 or less), and the X8R characteristics may not be satisfied. Therefore, in this embodiment, an upper limit is set on the amount of zirconium relative to titanium. Specifically, in the dielectric layer 11 in the capacitance region 14, the amount of zirconium relative to titanium is set to 10 at% or less. This ensures that a sufficient relative permittivity is obtained. The amount of zirconium relative to titanium is preferably 8 at% or less, and more preferably 6 at% or less.

[0045] (Regarding the second additive) However, adding zirconium to the dielectric layer 11 expands the lattice constant of the barium titanate crystal, causing rare earth elements such as holmium (Ho), dysprosium (Dy), and yttrium (Y), which are essential for lifespan, to dissolve more in the Ti site than in the Ba site, resulting in an acceptor excess and thus limiting the lifespan improvement effect.

[0046] Therefore, the inventors investigated rare earth elements with large ionic radii that readily substitute and solid-solve in the Ba site of barium titanate. As a result, they found that adding europium (Eu) improved the lifetime by about an order of magnitude compared to rare earth elements such as holmium, dysprosium, and yttrium. The reason why europium improves lifetime is not fully understood, but it is thought that europium is stable in both divalent and trivalent states, and among rare earth element ions that fluctuate between divalent and trivalent states and are stable in divalent states, it has the largest ionic radius, thus selectively substituting and solid-solving in the Ba site. Other rare earth elements are stable in trivalent states and unstable in divalent states.

[0047] 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]

[0048] Europium also becomes more solidly soluble in the shell portion 32 than in the core portion 31. Therefore, the europium concentration in the shell portion 32 is higher than the europium concentration in the core portion 31.

[0049] In the dielectric layer 11 of the capacitance region 14, if the amount of europium relative to titanium in barium titanate, which is the main component of the dielectric layer 11 (the amount of europium (at%) when titanium is set to 100 at%, there is a risk that a sufficiently long lifespan cannot be obtained. Therefore, in this embodiment, a lower limit is set for the amount of europium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of europium relative to titanium is set to 0.2 at% or more. Preferably, the amount of europium relative to titanium is 0.5 at% or more, and more preferably 1 at% or more.

[0050] On the other hand, if the amount of europium relative to titanium is too high in the dielectric layer 11 of the capacitance region 14, the dielectric layer 11 may become semiconductor-like, and a long lifespan may not be obtained. Therefore, in this embodiment, an upper limit is set on the amount of europium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of europium relative to titanium is set to 3.5 at% or less. Preferably, the amount of europium relative to titanium is 3 at% or less, and more preferably 2 at% or less.

[0051] Furthermore, if the amount of divalent europium added to the dielectric layer 11 in the capacitance region 14 is small, a sufficiently long lifespan may not be obtained. Therefore, it is preferable to set a lower limit on the amount of divalent europium in the dielectric layer 11 in the capacitance region 14. For example, in the dielectric layer 11 in the capacitance region 14, it is preferable that divalent europium accounts for 21% or more of the total europium, and more preferably 26% or more.

[0052] In order to increase the proportion of divalent europium, it is necessary to reduce a large amount of trivalent europium. However, during the annealing process to reduce europium to divalent europium, grain growth may occur in the dielectric layer 11 during the period in which a large amount of trivalent europium is reduced. If grain growth occurs, the lifespan of the dielectric layer 11 may decrease. Therefore, if grain growth occurs in the dielectric layer 11, the effect of grain growth on reducing the lifespan may offset the effect of improving the lifespan of the valence of europium, and the internal electrode layer 12 may not be able to maintain its structure due to grain growth, potentially causing a short circuit. For this reason, it is preferable to set an upper limit on the amount of divalent europium in the dielectric layer 11 of the capacitance region 14. For example, in the dielectric layer 11 of the capacitance region 14, it is preferable that divalent europium accounts for 80% or less of the total europium, more preferably 70% or less, and even more preferably 59% or less.

[0053] (Regarding the third additive) However, some europium may dissolve in the Ba site as a trivalent electron, potentially acting as a donor and degrading the insulating properties. The inventors have found that co-doping with manganese (Mn), which reduces excess electrons, is effective in addressing this issue. Manganese not only enhances insulating properties, but its valency can be increased through re-oxidation treatment, reducing oxygen vacancies and further improving the lifespan.

[0054] In the dielectric layer 11 of the capacitance region 14, if the amount of manganese relative to titanium in barium titanate, the main component of the dielectric layer 11 (the amount of manganese (at%) when titanium is set to 100 at%, then there will be an acceptor shortage in the dielectric layer 11, and a long lifespan may not be obtained by making the dielectric layer 11 semiconductor-like. Therefore, in this embodiment, a lower limit is set on the amount of manganese relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of manganese relative to titanium is set to 0.5 at% or more. The amount of manganese relative to titanium is preferably 0.5 at% or more, and more preferably 1 at% or more.

[0055] On the other hand, in the dielectric layer 11 of the capacitance region 14, if the amount of manganese relative to titanium is high, the amount of oxygen vacancies may become excessive due to an excess of acceptors, which may reduce the lifespan. Therefore, in this embodiment, an upper limit is set on the amount of manganese relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of manganese relative to titanium is set to 4.5 at% or less. Preferably, the amount of manganese relative to titanium is 3 at% or less, and more preferably 2 at% or less.

[0056] (Regarding the fourth additive) The inventors have found that by adding at least one of strontium and calcium to the dielectric layer 11 of the capacitance region 14, in addition to manganese, the insulating properties of the dielectric layer 11 are improved, thereby extending the lifespan of the multilayer ceramic capacitor 100.

[0057] As shown in Table 1, Ba 2+It has an ionic radius of 1.61 Å in 12-coordinate. In contrast, Ca 2+ It has 12 coordination and an ionic radius of 1.34 Å. Sr 2+ Strontium has an ionic radius of 1.4 Å in 12-coordinate state. Thus, strontium and calcium have ionic radii close to those of barium. Therefore, strontium and calcium are generally thought to be solid-dissolved in the Ba site of barium titanate and are unlikely to act as acceptors. For this reason, regarding insulation, it is thought that divalent strontium and calcium, by solid-dissolving in the Ba site in place of some europium, reduce the solid-dissolution ratio of trivalent europium and improve insulation. On the other hand, regarding improved lifetime, it is thought that the solid-dissolution of divalent strontium and calcium ions, which have smaller ionic radii than divalent Ba ions, in barium titanate reduces the lattice, restricting the movement of oxygen vacancies and making dielectric breakdown less likely.

[0058] In the dielectric layer 11 of the capacitance region 14, if the amount of strontium relative to titanium in barium titanate, the main component of the dielectric layer 11 (the amount of strontium (at%) when titanium is set to 100 at%, it may not be possible to sufficiently improve the insulating properties of the dielectric layer 11. Therefore, in this embodiment, a lower limit is set for the amount of strontium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of strontium relative to titanium is set to 0.1 at% or more. Preferably, the amount of strontium relative to titanium is 0.2 at% or more, and more preferably 0.5 at% or more.

[0059] On the other hand, in the dielectric layer 11 of the capacitance region 14, if the amount of strontium relative to titanium is high, grain growth may progress, potentially reducing the lifespan. Therefore, in this embodiment, an upper limit is set on the amount of strontium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of strontium relative to titanium is set to 3 at% or less. Preferably, the amount of strontium relative to titanium is 2 at% or less, and more preferably 1 at% or less.

[0060] In the dielectric layer 11 of the capacitance region 14, if the amount of calcium relative to titanium in barium titanate, the main component of the dielectric layer 11 (calcium amount (at%) when titanium is set to 100 at%, it may not be possible to sufficiently improve the insulating properties of the dielectric layer 11. Therefore, in this embodiment, a lower limit is set for the amount of calcium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of calcium relative to titanium is set to 0.1 at% or more. Preferably, the amount of calcium relative to titanium is 0.2 at% or more, and more preferably 0.5 at% or more.

[0061] On the other hand, in the dielectric layer 11 of the capacitance region 14, if the amount of calcium relative to titanium is high, grain growth may progress and the lifespan may be reduced. Therefore, in this embodiment, an upper limit is set on the amount of calcium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of calcium relative to titanium is set to 3 at% or less. Preferably, the amount of calcium relative to titanium is 2 at% or less, and more preferably 1 at% or less.

[0062] Furthermore, when additives such as zirconium or manganese are dissolved in barium titanate, the Curie temperature of barium titanate may shift to a lower temperature than 125°C, potentially worsening the capacitance change rate at high temperatures. However, in this embodiment, the Curie point shifts to a higher temperature (e.g., 130°C), suppressing the deterioration of the capacitance change rate at high temperatures, and allowing the multilayer ceramic capacitor 100 to satisfy the X8R characteristics. The reason why the Curie point shifts to the higher temperature side is not fully understood, but it is presumed that the cause is the internal stress generated at the interface between the core portion 31, where the crystal lattice has contracted due to the solid solution of some europium beyond the shell portion 32 to the core portion 31, and the shell portion 32, where the crystal lattice has expanded due to the addition of a high concentration of zirconium.

[0063] Next, in the dielectric layer 11 of the capacitance region 14, if the amount of rare earth elements other than europium added is too large, the lifetime improvement effect of europium will be weakened, and a sufficient lifetime may not be obtained. Therefore, it is preferable to set an upper limit on the amount of rare earth elements other than europium added. Specifically, in the dielectric layer 11 of the capacitance region 14, it is preferable to make the atomic concentration of rare earth elements other than europium less than the atomic concentration of europium. If there are multiple types of rare earth elements other than europium, it is preferable to make the total atomic concentration of these multiple types of rare earth elements less than the atomic concentration of europium.

[0064] As described above, according to this embodiment, the dielectric layer 11 in the capacitance region is mainly composed of barium titanate and includes a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate, a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, thereby achieving both a long lifespan and excellent capacitance-temperature characteristics.

[0065] Next, the manufacturing method of the multilayer ceramic capacitor 100 will be described. Figure 5 is a diagram illustrating the flow of the manufacturing method of the multilayer ceramic capacitor 100.

[0066] (Process for producing raw material powder) First, a dielectric material is prepared for forming the dielectric layer 11. The A-site and B-site elements contained in the dielectric layer 11 are usually present in the form of a sintered body of ABO3 particles. For example, barium titanate is a tetragonal compound having a perovskite structure and exhibits a high dielectric constant. This barium titanate can generally be obtained by synthesizing barium titanate by reacting a titanium raw material such as titanium dioxide with a barium raw material such as barium carbonate. Various methods have been conventionally known for synthesizing the main component ceramic of the dielectric layer 11, such as the solid-phase method, the sol-gel method, and the hydrothermal method. In this embodiment, any of these can be employed.

[0067] A predetermined additive compound is added to the obtained ceramic powder according to the purpose. Examples of additive compounds include oxides of zirconium, magnesium, manganese, strontium, calcium, vanadium (V), chromium (Cr), europium, and oxides or glasses of cobalt (Co), nickel, lithium (Li), boron (B), sodium (Na), potassium (K), and silicon (Si). If necessary, oxides of rare earth elements other than europium (scandium (Sc), yttrium, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium, holmium, erbium (Er), thulium (Tm), Yb, and lutetium (Lu)) may also be added.

[0068] For example, a ceramic material is prepared by wet-mixing a ceramic raw material powder with a compound containing an additive, drying, and grinding. For example, the ceramic material obtained as described above may be ground to adjust the particle size as needed, or the particle size may be adjusted by combining this with a classification process. A dielectric material is obtained through the above steps. In the dielectric material, the amount of zirconium relative to titanium in barium titanate is 2 at% to 10 at%, the amount of europium relative to titanium is 0.2 at% to 3.5 at%, the amount of manganese relative to titanium is 0.5 at% to 4.5 at%, and at least one of the amount of strontium and calcium relative to titanium is 0.1 at% to 3 at%.

[0069] (Coating process) Next, a binder such as polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the obtained dielectric material and wet-mixed. Using the resulting slurry, a strip-shaped ceramic green sheet, for example, with a thickness of 0.5 μm or more, is coated onto a substrate using a die coater or doctor blade method and then dried.

[0070] (Internal electrode formation process) Next, a metal conductive paste containing an organic binder for forming internal electrodes is printed onto the surface of the ceramic green sheet by screen printing, gravure printing, or the like, to arrange an internal electrode pattern that alternately leads 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.

[0071] (Crimping process) Subsequently, the ceramic green sheet with the internal electrode pattern printed on it is punched out to a predetermined size, and with the substrate peeled off, the punched ceramic green sheet is stacked for a predetermined number of layers (e.g., 100 to 1000 layers) such 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 out to a pair of external electrodes 20a and 20b with different polarities. Cover sheets for forming the cover layer 13 are pressed onto the top and bottom of the stacked ceramic green sheet and cut to a predetermined chip size (e.g., 1.0 mm x 0.5 mm).

[0072] (Firing process) The ceramic laminate thus obtained is subjected to binder removal treatment in an N2 atmosphere, and then a metal paste that will serve as the base layer for the external electrodes 20a and 20b is applied by the dip method, and the oxygen partial pressure is 10 -12 MPa~10 -9 The product is fired in a reducing atmosphere at MPa and 1160°C to 1280°C for 5 minutes to 10 hours.

[0073] Furthermore, if the heating rate is set to a slow rate of about 10°C / h, the diffusion of rare earth elements and zirconium is promoted in the dielectric material barium titanate, and totally solid-solution particles are formed. In this case, a long lifetime can be obtained, but the dielectric constant becomes low, and the sintering stability and capacitance temperature characteristics tend to deteriorate. Therefore, in this embodiment, by setting the heating rate to 5000°C / h or more and 10000°C / h or less (for example, 6000°C / h), the diffusion of zirconium is suppressed, and a core-shell structure with a large zirconium concentration gradient can be formed.

[0074] Furthermore, by adjusting the firing conditions such as the particle size, firing temperature, and firing time of the barium titanate powder in the dielectric material, the median diameter of the crystal grains 17 in the dielectric layer 11 of the capacitance region 14 obtained after firing can be adjusted.

[0075] (Re-oxidation process) In order to return oxygen to the partially reduced main phase, barium titanate, of the dielectric layer 11 fired in a reducing atmosphere, heat treatment may be performed at approximately 1000°C in a mixed gas of N2 and water vapor, or at 500°C to 700°C in air, without oxidizing the internal electrode layer 12. This process is called the re-oxidation process.

[0076] (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. [Examples]

[0077] Below, a multilayer ceramic capacitor according to the embodiment was fabricated and its characteristics were investigated.

[0078] (Example 1) Barium titanate, ZrO2, rare earth oxides, MnCO3, SrCO3, CaCO3, SiO2, and an organic solvent were weighed in predetermined ratios and mixed and ground using φ0.5 mm zirconia beads. The zirconium content (Zr / Ti) of the barium titanate relative to titanium was set to 4 at%. The europium content (Eu / Ti) relative to titanium was set to 1 at%. The manganese content relative to titanium was set to 1 at%. The strontium content relative to titanium was set to 1 at%. No rare earth elements other than europium were added.

[0079] A ceramic green sheet was coated with a slurry obtained by adding a binder, an internal electrode pattern was printed with Ni paste, the layers were stacked, and cut into 1005 shapes to fabricate a 1005-shaped ceramic laminate. The ceramic laminate was heated to 1230°C at a heating rate of 6000°C / h for high-speed firing. To reduce oxygen defects caused by reduction firing, the multilayer ceramic capacitors were re-oxidized in a nitrogen atmosphere at 1000°C after firing.

[0080] The thickness of the dielectric layer after firing was 2.0 μm. The thickness of the dielectric layer was measured by polishing it with a polishing machine until the cross-section shown in Figure 6 was exposed, and then using images of the cross-section taken with an SEM (Scanning Electron Microscope), measuring the length at 20 points from each of five different fields of view, for a total of 100 measurements, and taking the average value of these measurements. As shown in Figure 6, the crystal grain size is almost uniform in the dielectric layer 11 of the capacitance region. This is thought to be because abnormal grain growth was suppressed by setting the amount of zirconium relative to titanium to between 2 at% and 10 at%.

[0081] Figure 7 shows a TEM (Transmission Electron Microscope) image of the dielectric layer in the capacitance region. As shown in Figure 7, a core portion 31 and a shell portion 32 covering the core portion 31 were identified in the dielectric layer in the capacitance region after firing. Figure 8(a) shows the measurement results of TEM-EDS (Energy Dispersive X-ray Spectroscopy) analysis of the shell portion 32. Figure 8(b) shows the measurement results of TEM-EDS analysis of the core portion 31. As shown in Figures 8(a) and 8(b), it can be seen that the zirconium concentration is higher in the shell portion 32 than in the core portion 31. Europium was also detected in the core portion 31.

[0082] X8R characteristics were measured at 1 kHz, 1 Vrms, in the range of -55°C to 150°C. Dielectric constant was calculated from the capacitance at 25°C using dielectric thickness and electrode area. Life evaluation was performed by testing 10 samples at a high temperature and high electric field of 150°C and 50 V / μm until all samples failed, and the average time was used as the life value. Table 2 shows the results of the accelerated life test and the X8R characteristic evaluation. For accelerated life, a value of 3000 min or more was judged as a pass ("○"), and less than 3000 min was judged as a fail ("×"). For temperature characteristics, a value of "○" was judged as a pass if the X8R characteristics were met, and a value of "×" was judged as a fail if the X8R characteristics were not met. If both of these items were passed, the overall judgment was a pass ("○"), and if even one item was failed, the overall judgment was a fail ("×").

[0083] For Example 1, the overall evaluation was judged as a pass ("○"). This is thought to be because the dielectric layer 11 in the capacitance region was mainly composed of barium titanate and contained a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate, a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, which enabled both a long lifespan and excellent capacitance-temperature characteristics. Similar results were obtained when the same amount of calcium was used instead of strontium.

[0084] (Comparative Example 1) In Comparative Example 1, ytterbium was used instead of europium. All other conditions were the same as in Example 1.

[0085] (Comparative Example 2) In Comparative Example 2, holmium was used instead of europium. All other conditions were the same as in Example 1.

[0086] (Comparative Example 3) In Comparative Example 3, dysprosium was used instead of europium. All other conditions were the same as in Example 1.

[0087] (Comparative Example 4) In Comparative Example 4, terbium was used instead of europium. All other conditions were the same as in Example 1.

[0088] (Comparative Example 5) In Comparative Example 5, gadolinium was used instead of europium. All other conditions were the same as in Example 1.

[0089] (Comparative Example 6) In Comparative Example 6, neodymium was used instead of europium. Other conditions were the same as in Example 1.

[0090] (Comparative Example 7) In Comparative Example 7, praseodymium was used instead of europium. Other conditions were the same as in Example 1.

[0091] (Comparative Example 8) In Comparative Example 8, cerium was used instead of europium. All other conditions were the same as in Example 1.

[0092] (Comparative Example 9) In Comparative Example 9, lanthanum was used instead of europium. All other conditions were the same as in Example 1.

[0093] For Comparative Examples 1-9, the accelerated lifetime and X8R characteristics were measured and an overall evaluation was performed, similar to Example 1. In all of Comparative Examples 1-9, the accelerated lifetime was judged to be unsatisfactory. This is thought to be because rare earth elements other than europium were used. Furthermore, in all of Comparative Examples 2-9, the X8R characteristics were not met. This is also thought to be because rare earth elements other than europium were used. Similar results were obtained in Comparative Examples 1-9 when the same amount of calcium was used instead of strontium.

[0094] (Comparative Example 10) In Comparative Example 10, the amount of zirconium relative to titanium was set to 0.5 at%. Other conditions were the same as in Example 1.

[0095] (Comparative Example 11) In Comparative Example 11, the amount of zirconium relative to titanium was set to 1 at%. Other conditions were the same as in Example 1. (Example 2) In Example 2, the amount of zirconium relative to titanium was set to 2 at%. Other conditions were the same as in Example 1.

[0096] (Example 3) In Example 3, the amount of zirconium relative to titanium was set to 6 at%. Other conditions were the same as in Example 1.

[0097] (Example 4) In Example 4, the amount of zirconium relative to titanium was set to 8 at%. Other conditions were the same as in Example 1.

[0098] (Example 5) In Example 5, the amount of zirconium relative to titanium was set to 10 at%. Other conditions were the same as in Example 1.

[0099] (Comparative Example 12) In Comparative Example 12, the amount of zirconium relative to titanium was set to 20 at%. Other conditions were the same as in Example 1.

[0100] For Examples 2-5 and Comparative Examples 10-12, the accelerated lifetime and X8R characteristics were measured and an overall evaluation was performed, similar to Example 1. Examples 2-5 were judged to pass ("〇"). This is thought to be because the dielectric layer 11 in the capacitance region was mainly composed of barium titanate and contained a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate, a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, which allowed for both a long lifetime and excellent capacitance-temperature characteristics. In contrast, Comparative Examples 10 and 11 failed the accelerated lifetime test. This is thought to be because the low amount of zirconium added prevented the maintenance of the core-shell structure described in Figures 4(a) and 4(b), leading to localized abnormal grain growth and a failure to achieve the desired lifespan. Figure 9 shows an SEM image of the stacked cross-section of the dielectric layer 11 and the internal electrode layer 12 in the capacitance region for Comparative Example 11. As shown in Figure 9, abnormal grain growth was confirmed to have occurred in the dielectric layer in the capacitance region. In Comparative Example 13, the temperature characteristics were unsatisfactory. This is thought to be because the amount of zirconium added was too high. Similar results were obtained for Examples 2-4 and Comparative Examples 10-13 even when the same amount of calcium was used instead of strontium.

[0101] (Comparative Example 13) In Comparative Example 13, the amount of europium relative to titanium was set to 0.05 at%. Other conditions were the same as in Example 1.

[0102] (Comparative Example 14) In Comparative Example 14, the amount of europium relative to titanium was set to 0.1 at%. Other conditions were the same as in Example 1.

[0103] (Example 6) In Example 6, the amount of europium relative to titanium was set to 0.5 at%. Other conditions were the same as in Example 1.

[0104] (Example 7) In Example 7, the amount of europium relative to titanium was set to 2 at%. Other conditions were the same as in Example 1.

[0105] (Example 8) In Example 8, the amount of europium relative to titanium was set to 3 at%. Other conditions were the same as in Example 1.

[0106] (Comparative Example 15) In Comparative Example 15, the amount of europium relative to titanium was set to 4 at%. Other conditions were the same as in Example 1.

[0107] For Examples 6-8 and Comparative Examples 13-15, the accelerated lifetime and X8R characteristics were measured and an overall evaluation was performed, similar to Example 1. Examples 6-8 received a passing grade ("〇"). This is thought to be because the dielectric layer 11 in the capacitance region was mainly composed of barium titanate and contained a first additive with 2 at% to 10 at% zirconium relative to the titanium of the barium titanate, a second additive with 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, a third additive with 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate, and a fourth additive with 0.1 at% to 3 at% strontium or calcium relative to the titanium of the barium titanate, which allowed for both a long lifetime and excellent capacitance-temperature characteristics. In contrast, Comparative Examples 14 and 15 failed the accelerated lifetime test. This is thought to be because the amount of europium added was insufficient, preventing sufficient long lifetime development. Comparative Example 16 also failed the accelerated lifetime test. This is thought to be because the amount of europium added was too high, preventing the semiconductor effect from extending the lifetime. Similar results were obtained in Examples 6-8 and Comparative Examples 13-15 when the same amount of calcium was used instead of strontium.

[0108] (Comparative Example 16) In Comparative Example 16, the amount of manganese relative to titanium was set to 0.1 at%. Other conditions were the same as in Example 1.

[0109] (Example 9) In Example 9, the amount of manganese relative to titanium was set to 0.5 at%. Other conditions were the same as in Example 1.

[0110] (Example 10) In Example 10, the amount of manganese relative to titanium was set to 2 at%. Other conditions were the same as in Example 1.

[0111] (Example 11) In Example 11, the amount of manganese relative to titanium was set to 3 at%. Other conditions were the same as in Example 1.

[0112] (Comparative Example 17) In Comparative Example 17, the amount of manganese relative to titanium was set to 5 at%. Other conditions were the same as in Example 1.

[0113] (Comparative Example 18) In Comparative Example 18, the amount of manganese relative to titanium was set to 10 at%. Other conditions were the same as in Example 1.

[0114] For Examples 9-11 and Comparative Examples 16-18, the accelerated lifetime and X8R characteristics were measured and an overall evaluation was performed, similar to Example 1. In Examples 8-10, the overall evaluation was judged as passing ("○"). This is thought to be because the dielectric layer 11 in the capacitance region was mainly composed of barium titanate and contained a first additive containing 2 at% to 10 at% zirconium relative to the titanium of the barium titanate, a second additive containing 0.2 at% to 3.5 at% europium relative to the titanium of the barium titanate, a third additive containing 0.5 at% to 4.5 at% manganese relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium or calcium relative to the titanium of the barium titanate, which allowed for both a long lifetime and excellent capacitance-temperature characteristics. In contrast, Comparative Example 17 failed the accelerated lifetime test. This is thought to be because there was an acceptor shortage, causing the dielectric layer to become semiconductor-like. In Comparative Examples 17 and 18, the accelerated lifetime also failed. This is thought to be due to an excess of acceptors. Similar results were obtained in Examples 9-11 and Comparative Examples 16-18 when the same amount of calcium was used instead of strontium.

[0115] (Comparative Example 19) In Comparative Example 19, the amount of strontium relative to titanium was set to 0.05 at%. Other conditions were the same as in Example 1.

[0116] (Example 12) In Example 12, the amount of strontium relative to titanium was set to 0.1 at%. Other conditions were the same as in Example 1.

[0117] (Example 13) In Example 13, the amount of strontium relative to titanium was set to 0.3 at%. Other conditions were the same as in Example 1.

[0118] (Example 14) In Example 14, the amount of strontium relative to titanium was set to 0.5 at%. Other conditions were the same as in Example 1.

[0119] (Comparative Example 20) In Comparative Example 20, the amount of strontium relative to titanium was set to 5 at%. Other conditions were the same as in Example 1.

[0120] (Comparative Example 21) In Comparative Example 21, the amount of strontium relative to titanium was set to 10 at%. Other conditions were the same as in Example 1.

[0121] For Examples 12-14 and Comparative Examples 19-21, accelerated lifetime and X8R characteristics were measured and an overall evaluation was performed, similar to Example 1. Examples 12-14 received a passing grade ("〇"). This is thought to be because the dielectric layer 11 in the capacitance region was mainly composed of barium titanate and contained a first additive containing 1 at% to 10 at% zirconium relative to the titanium in the barium titanate, a second additive containing 0.1 at% to 4 at% europium relative to the titanium in the barium titanate, a third additive containing 0.5 at% to 5 at% manganese relative to the titanium in the barium titanate, and a fourth additive containing at least one of strontium or calcium relative to the titanium in the barium titanate, resulting in both a long lifetime and excellent capacitance-temperature characteristics. In contrast, Comparative Example 19 failed the X8R characteristics test. This is thought to be because the amount of strontium added was insufficient. In Comparative Examples 20-21, the accelerated life test was unsuccessful. This is thought to be because the amount of strontium added was too high, resulting in grain growth. Similar results were obtained in Examples 12-14 and Comparative Examples 19-21 when the same amount of calcium was used instead of strontium.

[0122] (Comparative Example 22) In Comparative Example 22, holmium was added at a concentration of 1 at% relative to titanium, in addition to the conditions of Example 1.

[0123] For Comparative Example 22, the accelerated lifetime and X8R characteristics were measured in the same manner as in Example 1, and an overall evaluation was made. Comparative Example 22 failed both the accelerated lifetime and temperature characteristics. This is thought to be because europium was not present in a greater quantity than other rare earth elements. [Table 2]

[0124] 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]

[0125] 10 stacked chips 11 Dielectric layer 12 Internal electrode layer 13. Cover layer 14 capacity area 15 End margin 16 Side margins 20a,20b external electrode 100 Multilayer Ceramic Capacitors

Claims

1. A main component including barium titanate; A first additive containing zirconium in an amount of 2 at% to 10 at% relative to the titanium of the barium titanate; a second additive containing europium in an amount of 0.2 at% or more and 3.5 at% or less relative to the titanium of the barium titanate, and containing rare earth elements other than europium in an amount less than that of europium; A third additive containing manganese in an amount of 0.5 at% or more and 4.5 at% or less relative to the titanium of the barium titanate; and a fourth additive containing at least one of strontium and calcium in an amount of 0.1 at % or more and 3 at % or less relative to the titanium in the barium titanate.

2. 2. The dielectric composition according to claim 1, comprising a dielectric crystal having a core portion in which europium is dissolved and a shell portion that covers said core portion and has a higher zirconium concentration than said core portion.

3. 3. The dielectric composition according to claim 1, wherein the second additive contains divalent europium and trivalent europium, and the divalent europium accounts for 21% or more and 80% or less of the total europium contained in the second additive.

4. 4. The dielectric composition according to claim 1, wherein the first additive contains zirconium in an amount of 2 at % or more and 8 at % or less relative to the titanium in the barium titanate.

5. 5. The dielectric composition according to claim 1, wherein the second additive contains europium in an amount of 0.5 at % or more and 3 at % or less relative to the titanium in the barium titanate.

6. The dielectric composition according to claim 1 , wherein the third additive contains manganese in an amount of 0.5 at % or more and 3 at % or less relative to the titanium in the barium titanate.

7. 7. The dielectric composition according to claim 1, wherein the fourth additive contains at least one of strontium and calcium in an amount of 0.1 at % or more and 1 at % or less relative to the titanium of the barium titanate.

8. a plurality of dielectric layers including a main component including barium titanate, a first additive including zirconium at 2 at% or more and 10 at% or less relative to the titanium of the barium titanate, a second additive including europium at 0.2 at% or more and 3.5 at% or less relative to the titanium of the barium titanate, and containing rare earth elements other than europium in an amount less than europium, a third additive including manganese at 0.5 at% or more and 4.5 at% or less relative to the titanium of the barium titanate, and a fourth additive including at least one of strontium and calcium at 0.1 at% or more and 3 at% or less relative to the titanium of the barium titanate; a plurality of internal electrode layers laminated with the plurality of dielectric layers interposed therebetween; and external electrodes electrically connected to the plurality of internal electrodes.

9. 9. The multilayer ceramic electronic component according to claim 8, wherein the plurality of dielectric layers include dielectric crystals having a core portion in which europium is dissolved and a shell portion that covers the core portion and has a higher zirconium concentration than the core portion.

10. 10. The multilayer ceramic electronic component according to claim 8, wherein the second additive contains divalent europium and trivalent europium, and the divalent europium accounts for 21% or more and 80% or less of the total europium contained in the second additive.

11. 11. The multilayer ceramic electronic component according to claim 8, wherein the first additive contains zirconium in an amount of 2 at % to 8 at % relative to the titanium in the barium titanate.

12. 12. The multilayer ceramic electronic component according to claim 8, wherein the second additive contains europium in an amount of 0.5 at % to 3 at % relative to the titanium in the barium titanate.

13. 13. The multilayer ceramic electronic component according to claim 8, wherein the third additive contains manganese in an amount of 0.5 at % to 3 at % relative to the titanium in the barium titanate.

14. 14. The multilayer ceramic electronic component according to claim 8, wherein the fourth additive contains at least one of strontium and calcium in an amount of 0.1 at % to 1 at % relative to the titanium in the barium titanate.

15. The multilayer ceramic electronic component according to claim 8 , which satisfies X8R characteristics.

16. a step of forming a ceramic green sheet including a main component containing barium titanate, a first additive containing zirconium at 2 at% to 10 at% relative to the titanium of the barium titanate, a second additive containing europium at 0.2 at% to 3.5 at% relative to the titanium of the barium titanate and containing fewer rare earth elements other than europium than europium, a third additive containing manganese at 0.5 at% to 4.5 at% relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium and calcium at 0.1 at% to 3 at% relative to the titanium of the barium titanate; and firing the ceramic green sheet at a temperature increase rate of 5,000° C. / h or more and 10,000° C. / h or less.

17. a coating process for forming a ceramic green sheet including a main component containing barium titanate, a first additive containing zirconium at 2 at% to 10 at% relative to the titanium of the barium titanate, a second additive containing europium at 0.2 at% to 3.5 at% relative to the titanium of the barium titanate and containing fewer rare earth elements other than europium than europium, a third additive containing manganese at 0.5 at% to 4.5 at% relative to the titanium of the barium titanate, and a fourth additive containing at least one of strontium and calcium at 0.1 at% to 3 at% relative to the titanium of the barium titanate; an internal electrode forming step of forming an internal electrode pattern on the ceramic green sheet; a pressure bonding step of stacking the ceramic green sheets on which the internal electrode patterns are formed; and a firing step of firing the laminated ceramic green sheets at a temperature rise rate of 5,000°C / h or more and 10,000°C / h or less to form a plurality of dielectric layers and a plurality of internal electrodes.

18. 18. The method for producing a multilayer ceramic electronic component according to claim 17, further comprising a reoxidation step of heat-treating the plurality of dielectric layers and the plurality of internal electrodes after the firing step.

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