Multilayer ceramic capacitor and manufacturing method of them

Abstract

To provide a multilayer ceramic capacitor having an excellent characteristic of a reliability variation and a manufacturing method of them.SOLUTION: A multilayer ceramic capacitor according to an embodiment, contains: a capacitor body containing a dielectric layer and an internal electrode layer; and an external electrode that is arranged to an outside of the capacitor body. The dielectric layer contains a plurality of dielectric crystal grains, each dielectric crystal grain contains a core part and a shell part surrounding at least one part of the core part, and the shell part contains: a main component of a barium titanate system containing barium (Ba) and titanium (Ti); and a rare earth element (R) containing dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination of them. A R / Ba atom ratio variation coefficient (CV) obtained by a formula 1 in the shell part and a R / Ti atom ratio variation coefficient (CV) exceeds 0 and is less than 0.19.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a multilayer ceramic capacitor and a manufacturing method thereof. [Background technology]

[0002] Electronic components that use ceramic materials include capacitors, inductors, piezoelectric elements, varistors, thermistors, etc. Among these ceramic electronic components, multilayer ceramic capacitors (MLCCs) have the advantages of being small, high capacity, and easy to mount, and can be used in a variety of electronic devices.

[0003] For example, multilayer ceramic capacitors (MLCCs) can be used as chip-type capacitors that are mounted on substrates of various electronic products such as visual devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light-emitting diodes (OLEDs), computers, personal portable terminals, and smartphones to charge or discharge electricity.

[0004] Recently, as MLCCs become more highly integrated, they are becoming thinner and thinner, and there is a demand to ensure high reliability under such thin layer designs. Summary of the Invention [Problem to be solved by the invention]

[0005] One embodiment provides a multilayer ceramic capacitor with excellent reliability variation characteristics.

[0006] Another embodiment provides a method for manufacturing the multilayer ceramic capacitor. [Means for solving the problem]

[0007] One embodiment provides a multilayer ceramic capacitor including a capacitor body including a dielectric layer and an internal electrode layer, and an external electrode disposed on an outside of the capacitor body, the dielectric layer including a plurality of dielectric crystal grains, the dielectric crystal grains including a core portion and a shell portion surrounding at least a portion of the core portion, the shell portion including a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum) or a combination thereof, and a coefficient of variation (CV) of an R / Ba atomic ratio and a coefficient of variation (CV) of an R / Ti atomic ratio in the shell portion obtained by the following Equation 1 is more than 0 and less than 0.19.

[0008] [Formula 1] Coefficient of variation of atomic ratio (CV) = {standard deviation of atomic ratio (σ) / average of atomic ratio} (In the above formula 1, the standard deviation (σ) of the atomic ratio is the square root of the mean of the squares of the deviations.)

[0009] The rare earth element in the shell portion may include dysprosium (Dy), and the Dy / Ba atomic ratio variation coefficient and the Dy / Ti atomic ratio variation coefficient obtained by Equation 1 in the shell portion may be more than 0 and less than 0.19.

[0010] The R / Ba atomic ratio in the shell portion may be 0.015 to 0.02.

[0011] The rare earth element in the shell portion may include dysprosium (Dy), and the Dy / Ba atomic ratio in the shell portion may be 0.015 to 0.02.

[0012] The R / Ti atomic ratio in the shell portion may be 0.012 to 0.02.

[0013] The rare earth element in the shell portion may include dysprosium (Dy), and the Dy / Ti atomic ratio in the shell portion may be 0.012 to 0.02.

[0014] The core portion may include a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof.

[0015] The R / Ba atomic ratio in the core portion may be 0.005 to 0.01.

[0016] The rare earth element in the core portion may include dysprosium (Dy), and the Dy / Ba atomic ratio in the core portion may be 0.005 to 0.01.

[0017] The R / Ti atomic ratio in the core portion may be 0.004 to 0.01.

[0018] The rare earth element in the core portion may include dysprosium (Dy), and the Dy / Ti atomic ratio in the core portion may be 0.004 to 0.01.

[0019] Another embodiment of the present invention relates to a method for manufacturing a dielectric powder having a surface coated with a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum) or a combination thereof, the steps of: manufacturing a dielectric green sheet using a dielectric slurry including the dielectric powder, forming a conductive paste layer on a surface of the dielectric green sheet, laminating the dielectric green sheets having the conductive paste layer formed thereon to manufacture a dielectric green sheet laminate, and firing the dielectric green sheet laminate to manufacture a capacitor body including a dielectric layer and an internal electrode layer. forming an external electrode on one surface of a capacitor body, the dielectric layer including a core portion and a shell portion surrounding at least a portion of the core portion, the shell portion including a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum) or a combination thereof, wherein the R / Ba atomic ratio coefficient of variation (CV) and the R / Ti atomic ratio coefficient of variation (CV) in the shell portion obtained by Equation 1 are greater than 0 and less than 0.19.

[0020] The step of preparing the dielectric powder may include mixing a barium titanate-based main component and a rare earth element complex compound.

[0021] The rare earth element complex compound may include a dysprosium (Dy) complex compound, a terbium (Tb) complex compound, an yttrium (Y) complex compound, a La (lanthanum) complex compound, or a combination thereof.

[0022] The rare earth element complex compound can be mixed in an amount of 0.1 to 5 parts by mol with respect to 100 parts by mol of the barium titanate-based main component. Effect of the Invention

[0023] The multilayer ceramic capacitor according to an embodiment has a dielectric in which an additive component is uniformly distributed, thereby improving reliability variation characteristics. [Brief description of the drawings]

[0024] [Figure 1] 1 is a perspective view illustrating a multilayer ceramic capacitor according to an embodiment; [Diagram 2] 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. [Diagram 3] 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. [Figure 4] FIG. 2 is a schematic diagram illustrating a structure of a dielectric grain according to one embodiment. [Diagram 5] 1 is a low-magnification TEM image of a dielectric layer according to Example 1. [Figure 6] 1 is a high-magnification TEM image of a dielectric layer according to Example 1. [Figure 7] 1 is a low-magnification TEM image of a dielectric layer according to Comparative Example 1. [Figure 8] 1 is a high-magnification TEM image of a dielectric layer according to Comparative Example 1. [Figure 9] 4 is a graph showing the high-temperature stress reliability of the multilayer ceramic capacitor according to Example 1. [Figure 10] 1 is a graph showing high-temperature stress reliability of the multilayer ceramic capacitor according to Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. In the drawings, parts that are unnecessary for the explanation are omitted in order to clearly explain the present invention, and the same or similar components are given the same reference numerals throughout the specification. In addition, in the accompanying drawings, some components are exaggerated, omitted, or illustrated in a schematic manner, and the size of each component does not completely reflect the actual size.

[0026] The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and the attached drawings do not limit the technical ideas disclosed in this specification, and it should be understood that the drawings include all modifications, equivalents, and alternatives included in the idea and technical scope of the present invention.

[0027] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited to the terms. The terms are used only to distinguish one component from another.

[0028] In addition, when a part such as a layer, film, region, or plate is said to be "on" or "above" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. In addition, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" the side opposite to gravity.

[0029] Throughout the specification, the terms "comprise" or "have" and the like are intended to specify the presence of any feature, numeral, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the presence or additional possibility of one or more other features, numerals, steps, operations, components, parts, or combinations thereof. Thus, when a part is said to "comprise" a certain element, this means that it can further include other elements, but not to the exclusion of other elements, unless specifically stated to the contrary.

[0030] Also, throughout the specification, "in a plane" means when the subject part is viewed from above, and "in cross section" means when the subject part is cut vertically and viewed from the side.

[0031] Furthermore, throughout the specification, when the term "connected" is used, this does not only mean that two or more components are directly connected, but also that two or more components are indirectly connected through other components, or that they are not only physically connected but also electrically connected, or that they are referred to by different names depending on their location or function but are integrated.

[0032] Hereinafter, a multilayer ceramic capacitor according to an embodiment will be described with reference to FIGS.

[0033] FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to one embodiment, FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. 1, and FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. 1.

[0034] The L axis, W axis, and T axis shown in FIGS. 1 to 3 respectively indicate the length direction, width direction, and thickness direction of the capacitor body 110. Here, the thickness direction (T axis direction) may be a direction perpendicular to the wide surface (main surface) of the sheet-shaped component, and can be used as the same concept as the lamination direction in which the dielectric layers 111 are laminated, for example. The length direction (L axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet-shaped component and approximately perpendicular to the thickness direction (T axis direction), and can be a direction in which the first external electrode 131 and the second external electrode 132 are located on both sides, for example. The width direction (W axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet-shaped component and approximately perpendicular to the thickness direction (T axis direction) and the length direction (L axis direction), and the length of the sheet-shaped component in the length direction (L axis direction) may be longer than the length of the width direction (W axis direction).

[0035] 1 to 3, a multilayer ceramic capacitor 100 according to the present embodiment includes a capacitor body 110 and external electrodes 131 and 132 disposed on the outer side of the capacitor body 110. The external electrodes 131 and 132 may include a first external electrode 131 and a second external electrode 132 disposed on opposite ends of the capacitor body 110 in a longitudinal direction (L-axis direction).

[0036] The capacitor body 110 may be, for example, generally hexahedral in shape.

[0037] For the convenience of describing one embodiment, the two surfaces of the capacitor body 110 that face each other in the thickness direction (T-axis direction) are defined as the first surface and the second surface, the two surfaces connected to the first surface and the second surface and facing each other in the length direction (L-axis direction) are defined as the third surface and the fourth surface, and the two surfaces connected to the first surface and the second surface, connected to the third surface and the fourth surface, and facing each other in the width direction (W-axis direction) are defined as the fifth surface and the sixth surface.

[0038] As an example, the first surface, which is the lower surface, may be the surface facing the mounting direction. The first to sixth surfaces may be flat, but the embodiment is not limited to this. For example, the first to sixth surfaces may be curved surfaces with a convex center, and the corners that are the boundaries between the surfaces may be rounded.

[0039] The shape and size of the capacitor body 110 and the number of laminated dielectric layers 111 are not limited to those shown in the drawings of this embodiment.

[0040] The capacitor body 110 includes a plurality of dielectric layers 111 and internal electrode layers 121 and 122. Specifically, the capacitor body 110 includes a plurality of dielectric layers 111 and first internal electrodes 121 and second internal electrodes 122 that are alternately arranged in the thickness direction (T-axis direction) with the dielectric layers 111 sandwiched therebetween.

[0041] At this time, the boundaries between the adjacent dielectric layers 111 of the capacitor body 110 may be integrated to such an extent that it is difficult to confirm them without using a scanning electron microscope (SEM).

[0042] The capacitor body 110 may have an active region. The active region is a region where the dielectric layers 111 and the internal electrode layers 121 and 122 are alternately arranged, and is a portion that contributes to forming the capacitance of the multilayer ceramic capacitor 100. Specifically, the active region may be a region where the first internal electrodes 121 or the second internal electrodes 122 stacked in the thickness direction (T-axis direction) overlap each other.

[0043] In addition, the capacitor body 110 may further include a cover portion and a side margin portion.

[0044] The cover portion is a thickness direction margin portion and can be disposed on the first surface side and the second surface side of the active region in the thickness direction (T-axis direction). Such a cover portion can be a single dielectric layer 111 or two or more dielectric layers 111 laminated on the upper and lower surfaces of the active region, respectively.

[0045] The side margins can be regarded as side cover parts, and can be disposed on both opposing ends of the active area in the width direction (W-axis direction), i.e., on the fifth and sixth surface sides, respectively. The side margins can be formed by applying a conductive paste layer for an internal electrode layer to the surface of a dielectric green sheet, applying the conductive paste layer only to a part of the surface of the dielectric green sheet, laminating dielectric green sheets not coated with the conductive paste layer on both side surfaces of the dielectric green sheet, and then firing the laminate, but the method is not limited to this.

[0046] The cover portion and the side margin portion serve to prevent the first internal electrode 121 and the second internal electrode 122 from being damaged by physical or chemical stress.

[0047] The dielectric layer 111 includes dielectric grains. The structure of the dielectric grains will be described with reference to FIG.

[0048] FIG. 4 is a schematic diagram illustrating a structure of a dielectric grain according to one embodiment.

[0049] Referring to FIG. 4, a dielectric crystal grain 10 according to an embodiment has a core-shell structure including a core portion 11 and a shell portion 12 surrounding at least a portion of the core portion 11 .

[0050] The shell portion 12 may include a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element. The rare earth element may include dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof.

[0051] The rare earth element may be uniformly distributed on the surface of the core portion 11 in the shell portion 12. According to an embodiment, the rare earth element may be uniformly distributed on the surface of the core portion 11, which is a dielectric material, by ionizing an additive component such as a rare earth element. Specifically, a multilayer ceramic capacitor in which the rare earth element is uniformly distributed in the dielectric layer 111 may be obtained by using a dielectric powder in which the additive component is chemically adsorbed and coated on the surface of a barium titanate-based main component.

[0052] The barium titanate-based main component is a dielectric base material that has a high dielectric constant and contributes to the formation of the dielectric constant of the multilayer ceramic capacitor 100 .

[0053] The main component of barium titanate is, for example, BaTiO 3 , Ba(Ti,Zr)O 3 , Ba(Ti,Sn)O 3 , (Ba,Ca)TiO 3 , (Ba,Ca)(Ti,Ca)O 3 , (Ba,Ca)(Ti,Zr)O 3 , (Ba,Ca)(Ti,Sn)O 3 , (Ba,Sr)TiO 3 , (Ba,Sr)(Ti,Zr)O 3 , (Ba,Sr)(Ti,Sn)O 3 , or a combination thereof.

[0054] According to one embodiment, additive components such as rare earth elements are uniformly distributed on the surface of the core portion 11, i.e., uniformly distributed inside the dielectric layer 111, thereby improving the reliability variation characteristics of the multilayer ceramic capacitor.

[0055] Specifically, when the rare earth element is R, the coefficient of variation (CV) of the R / Ba atomic ratio in the shell portion 12 may be more than 0 and less than 0.19, for example, 0.01 to 0.17. The coefficient of variation (CV) of the R / Ti atomic ratio in the shell portion 12 may be more than 0 and less than 0.19, for example, 0.01 to 0.17. When the coefficient of variation of the R / Ba atomic ratio and the coefficient of variation of the R / Ti atomic ratio are each within the above range, it means that a rare earth element such as dysprosium (Dy) is uniformly distributed in the shell portion 12, specifically on the surface of the core portion 11, and thus a thin-layer multilayer ceramic capacitor having excellent reliability variation characteristics can be obtained.

[0056] The coefficient of variation (CV) of the R / Ba atomic ratio and the coefficient of variation (CV) of the R / Ti atomic ratio are each obtained by the following formula 1.

[0057] [Formula 1] Coefficient of variation of atomic ratio (CV) = {standard deviation of atomic ratio (σ) / average of atomic ratio} In the above formula 1, the standard deviation (σ) of the atomic ratio is calculated by squaring the deviations, adding them up, and then dividing the sum by the number of measurements to find the square root. That is, it means the square root of the average of the squares of the deviations as shown in the following formula 2.

[0058]

number

[0059] As an example, the rare earth element (R) contained in the shell portion 12 may be dysprosium (Dy). In this case, the coefficient of variation (CV) of the Dy / Ba atomic ratio obtained by the above formula 1 in the shell portion 12 may be more than 0 and less than 0.19, for example, 0.01 to 0.17. Also, the coefficient of variation (CV) of the Dy / Ti atomic ratio obtained by the above formula 1 in the shell portion 12 may be more than 0 and less than 0.19, for example, 0.01 to 0.17.

[0060] The R / Ba atomic ratio in the shell portion 12 may be 0.015 to 0.02, for example, 0.016 to 0.019. When the R / Ba atomic ratio in the shell portion 12 is within the above range, the high-temperature stress reliability of the multilayer ceramic capacitor can be improved.

[0061] As an example, the rare earth element (R) contained in the shell portion 12 may be dysprosium (Dy). In this case, the Dy / Ba atomic ratio in the shell portion 12 may be 0.015 to 0.02, for example, 0.016 to 0.019.

[0062] The R / Ti atomic ratio in the shell portion 12 may be 0.012 to 0.02, for example, 0.012 to 0.017. When the R / Ti atomic ratio in the shell portion 12 is within the above range, the high-temperature stress reliability of the multilayer ceramic capacitor can be improved.

[0063] As an example, the rare earth element (R) contained in the shell portion 12 may be dysprosium (Dy). In this case, the Dy / Ti atomic ratio in the shell portion 12 may be 0.012 to 0.02, for example, 0.012 to 0.017.

[0064] In the shell portion 12, the R / Ba atomic ratio, the R / Ti atomic ratio, and the coefficient of variation (CV) of the atomic ratio can be obtained by TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) analysis.

[0065] Specifically, the multilayer ceramic capacitor 100 is immersed in an epoxy mixture and cured, and then the W-axis and T-axis directions (WT directions) of the capacitor body 110 are polished to a depth of 1 / 2 in the L-axis direction, and then fixed and held in a vacuum atmosphere chamber to obtain a cross-sectional sample so that an active region where the dielectric layer 111 and the internal electrode layers 121 and 122 intersect can be observed. Then, the active region of the cross-sectional sample can be measured with a transmission electron microscope (TEM). For example, the TEM can be measured at an acceleration voltage of 200 kV using a Xe-FIB (focused ion beam) in an area of ​​about 1.3 μm×1.3 μm where at least one layer of the dielectric layer 111 is visible in the active region. Then, in the transmission electron microscope (TEM) image of the measured cross-sectional sample, EDS analysis can be performed on points in each shell part of at least one dielectric crystal grain in one dielectric layer, for example, points in each shell part of 1 to 20, 2 to 10, or 3 to 7 dielectric crystal grains. It may be an arithmetic average value of the R / Ba atomic ratio and the R / Ti atomic ratio at a point in each shell portion of the at least one dielectric crystal grain.

[0066] The core portion 11 may include a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element. The rare earth element may include dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof.

[0067] The barium titanate-based main component is a dielectric base material that has a high dielectric constant and contributes to the formation of the dielectric constant of the multilayer ceramic capacitor 100 .

[0068] The main component of barium titanate is, for example, BaTiO 3 , Ba(Ti,Zr)O 3 , Ba(Ti,Sn)O 3 , (Ba,Ca)TiO 3 , (Ba,Ca)(Ti,Ca)O 3, (Ba,Ca)(Ti,Zr)O 3 , (Ba,Ca)(Ti,Sn)O 3 , (Ba,Sr)TiO 3 , (Ba,Sr)(Ti,Zr)O 3 , (Ba,Sr)(Ti,Sn)O 3 , or a combination thereof.

[0069] During the manufacture of the dielectric powder, the rare earth element is contained in the core portion 11 by internal diffusion of the rare earth element coated on the surface of the barium titanate-based main component.

[0070] According to one embodiment, the core portion 11 contains a rare earth element such as dysprosium (Dy), thereby improving the thin layer reliability of the multilayer ceramic capacitor.

[0071] Specifically, when the rare earth element is R, the R / Ba atomic ratio in the core region 11 may be 0.005 to 0.01, for example, 0.006 to 0.009. When the R / Ba atomic ratio in the core region 11 is within the above range, the high temperature stress reliability of the multilayer ceramic capacitor can be improved.

[0072] As an example, the rare earth element (R) contained in the core region 11 may be dysprosium (Dy). In this case, the Dy / Ba atomic ratio in the core region 11 may be 0.005 to 0.01, for example, 0.006 to 0.009.

[0073] The R / Ti atomic ratio in the core portion 11 may be 0.004 to 0.01, for example, 0.004 to 0.008. When the R / Ti atomic ratio in the core portion 11 is within the above range, the high-temperature stress reliability of the multilayer ceramic capacitor can be improved.

[0074] As an example, the rare earth element (R) contained in the core region 11 may be dysprosium (Dy). In this case, the Dy / Ti atomic ratio in the core region 11 may be 0.004 to 0.01, for example, 0.004 to 0.008.

[0075] In the core portion 11, the R / Ba atomic ratio, the R / Ti atomic ratio, and the coefficient of variation (CV) of the atomic ratio can be obtained by TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) analysis.

[0076] Specifically, in a transmission electron microscope (TEM) image of a cross-sectional sample measured by the same method as described above, EDS analysis can be performed on a point in each core part of at least one dielectric crystal grain in one dielectric layer, for example, 1 to 20, 2 to 10, or 3 to 7 dielectric crystal grains. The R / Ba atomic ratio and the R / Ti atomic ratio at the point in each core part of the at least one dielectric crystal grain may be arithmetically averaged.

[0077] The average thickness (average length in the T-axis direction) of the dielectric layers 111 may be 2.0 μm to 8.0 μm, for example, 2.4 μm to 7.8 μm. When the average thickness of the dielectric layers 111 is within the above range, the multilayer ceramic capacitor has excellent reliability.

[0078] The average thickness of the dielectric layer 111 may be measured by immersing the multilayer ceramic capacitor 100 in an epoxy mixture, curing the multilayer ceramic capacitor 100, polishing the multilayer ceramic capacitor 100, and then performing ion milling and analyzing the multilayer ceramic capacitor 100 with a scanning electron microscope (SEM). The scanning electron microscope may be, for example, a Verios G4 product from Thermofisher Scientific, and the measurement conditions may be 10 kV, 0.2 nA, and the analysis magnification may be 100 times. Measurement may be performed so that at least one, three, five, or ten dielectric layers 111 are obtained. The average thickness of the dielectric layer 111 may be an arithmetic average value of the thicknesses of the dielectric layer 111 at ten points spaced apart from the reference point at a predetermined interval, with the center of the dielectric layer 111 in the length direction (L-axis direction) or width direction (W-axis direction) being set as a reference point in the scanning electron microscope (SEM) image. The interval between the 10 points may be adjusted according to the scale of a scanning electron microscope (SEM) image, and may be, for example, 1 μm to 100 μm, 1 μm to 50 μm, or 1 μm to 10 μm. In this case, all of the 10 points must be located within the dielectric layer 111, and if all of the 10 points are not located within the dielectric layer 111, the position of the reference point may be changed or the interval between the 10 points may be adjusted.

[0079] The first internal electrode 121 and the second internal electrode 122 are electrodes having different polarities and are alternately arranged to face each other along the T-axis direction with the dielectric layer 111 in between, and one end is exposed through the third and fourth surfaces of the capacitor body 110, respectively.

[0080] The first internal electrode 121 and the second internal electrode 122 are electrically insulated from each other by a dielectric layer 111 disposed between them.

[0081] Ends of the first internal electrode 121 and the second internal electrode 122 alternately exposed through the third and fourth surfaces of the capacitor body 110 are electrically connected to the first external electrode 131 and the second external electrode 132, respectively.

[0082] The first internal electrode 121 and the second internal electrode 122 include a conductive metal, and may include, for example, a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy thereof, for example, an Ag-Pd alloy.

[0083] The first internal electrode 121 and the second internal electrode 122 may also contain dielectric particles of the same composition as the ceramic material contained in the dielectric layer 111 .

[0084] The first internal electrode 121 and the second internal electrode 122 can be formed using a conductive paste containing a conductive metal. The conductive paste can be printed by screen printing or gravure printing.

[0085] The average thickness of the first internal electrode 121 and the second internal electrode 122 may be 0.1 μm to 2 μm. The average thickness of the first internal electrode 121 and the second internal electrode 122 can be measured by scanning electron microscope (SEM) analysis. Here, the scanning electron microscope (SEM) analysis is the same as the method for measuring the average thickness of the dielectric layer 111 described above, so the description thereof will be omitted.

[0086] The capacitor body 110 may be formed by firing a laminate in which a plurality of dielectric layers 111 and internal electrode layers 121 and 122 are laminated.

[0087] The first external electrode 131 and the second external electrode 132 are provided with voltages of different polarities and are electrically connected to the exposed portions of the first internal electrode 121 and the second internal electrode 122, respectively.

[0088] With the above-mentioned configuration, when a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charges are stored between the opposing first internal electrode 121 and second internal electrode 122. At this time, the capacitance of the multilayer ceramic capacitor 100 is proportional to the overlap area of ​​the first internal electrode 121 and the second internal electrode 122 that overlap each other along the T-axis direction in the active region.

[0089] The first external electrode 131 and the second external electrode 132 may each include a first connection portion and a second connection portion arranged on the third and fourth surfaces of the capacitor body 110, respectively, and connected to the first internal electrode 121 and the second internal electrode 122, and a first band portion and a second band portion arranged at the corner where the third and fourth surfaces of the capacitor body 110 meet the first and second surfaces or the fifth and sixth surfaces.

[0090] The first and second band parts extend from the first and second connecting parts to parts of the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. The first and second band parts can serve to improve the bonding strength between the first and second external electrodes 131 and 132.

[0091] The first external electrode 131 and the second external electrode 132 may each include a sintered metal layer in contact with the capacitor body 110, a conductive resin layer disposed to cover the sintered metal layer, and a plating layer disposed to cover the conductive resin layer.

[0092] The sintered metal layer can include a conductive metal and glass.

[0093] The conductive metal may include copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), lead (Pb), alloys thereof, or combinations thereof, for example, copper (Cu) may include copper (Cu) alloys. When the conductive metal includes copper, metals other than copper may be included in an amount of 5 molar parts or less per 100 molar parts of copper.

[0094] The glass may include a mixed oxide composition, such as one or more selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide. The transition metal may be selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni), the alkali metal may be selected from the group consisting of lithium (Li), sodium (Na), and potassium (K), and the alkaline earth metal may be one or more selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0095] Alternatively, the conductive resin layer may be formed on the sintered metal layer, for example, to completely cover the sintered metal layer. Alternatively, the first external electrode 131 and the second external electrode 132 may not include a sintered metal layer, in which case the conductive resin layer may be in direct contact with the capacitor body 110.

[0096] The conductive resin layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110, and the length of the region (i.e., band portion) where the conductive resin layer is extended to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 may be longer than the length of the region (i.e., band portion) where the sintered metal layer is extended to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. That is, the conductive resin layer is formed on the sintered metal layer to completely cover the sintered metal layer.

[0097] The conductive resin layer includes a resin and a conductive metal.

[0098] The resin contained in the conductive resin layer is not particularly limited as long as it has bonding and impact absorbing properties and can be mixed with the conductive metal powder to form a paste, and may include, for example, a phenolic resin, an acrylic resin, a silicone resin, an epoxy resin, or a polyimide resin.

[0099] The conductive metal contained in the conductive resin layer serves to electrically connect with the first internal electrode 121 and the second internal electrode 122 or the sintered metal layer.

[0100] The conductive metal contained in the conductive resin layer may have a spherical shape, a flake shape, or a combination thereof, that is, the conductive metal may be only in a flake shape, only in a spherical shape, or in a mixed shape of a flake shape and a spherical shape.

[0101] Here, the spherical shape may include a shape that is not a perfect sphere, for example, a shape in which the ratio of the major axis to the minor axis (major axis / minor axis) is 1.45 or less. The flake-shaped powder means a powder having a flat and elongated shape, and is not particularly limited, and may be, for example, a ratio of the major axis to the minor axis (major axis / minor axis) of 1.95 or more.

[0102] The first external electrode 131 and the second external electrode 132 may further include a plating layer disposed on the outer side of the conductive resin layer.

[0103] The plating layer may include nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), or lead (Pb) alone or in alloys thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or may be a form in which a nickel (Ni) plating layer and a tin (Sn) plating layer are sequentially laminated, or a form in which a tin (Sn) plating layer, a nickel (Ni) plating layer, and a tin (Sn) plating layer are sequentially laminated. The plating layer may also include a plurality of nickel (Ni) plating layers and / or a plurality of tin (Sn) plating layers.

[0104] The plating layer can improve the mountability of the multilayer capacitor 100 on a substrate, structural reliability, durability against the outside, heat resistance, and equivalent series resistance (ESR).

[0105] A method for manufacturing the multilayer ceramic capacitor 100 according to an embodiment will be described below.

[0106] The multilayer ceramic capacitor 100 according to an embodiment may be manufactured through the steps of: preparing a dielectric powder having a surface of a barium titanate-based main component coated with a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum) or a combination thereof; preparing a dielectric green sheet using a dielectric slurry including the dielectric powder, forming a conductive paste layer on a surface of the dielectric green sheet; laminating the dielectric green sheets having the conductive paste layer formed thereon to prepare a dielectric green sheet laminate; firing the dielectric green sheet laminate to prepare a capacitor body including a dielectric layer and an internal electrode layer; and forming an external electrode on one surface of the capacitor body.

[0107] Dielectric powder corresponding to dielectric grains, i.e., a dielectric powder in which the surface of a barium titanate-based main component is coated with a rare earth element such as dysprosium (Dy), can be prepared by mixing a barium titanate-based main component and a rare earth element complex compound.

[0108] To realize high-performance multilayer ceramic capacitors, it is necessary to make the dielectric thin and to make the additive microstructure uniform to a high level. The additive components in the form of oxides vary in size from tens of nm to several μm, and in order to disperse them uniformly, attempts are being made to crush the oxide additives into smaller pieces by performing strong milling. However, there are obstacles such as impurities mixed in during the crushing process and changes in the component ratio of the additive components and the dielectric material due to incomplete crushing, so there are limitations to the physical crushing process.

[0109] According to one embodiment, unlike a method of physically mixing an additive component in the form of an oxide with a barium titanate-based main component, the ionized additive component can be chemically adsorbed with the barium titanate-based main component to induce a more uniform distribution of the additive component.

[0110] The barium titanate-based main component can be produced by various methods such as solid-phase synthesis, hydrothermal synthesis, and sol-gel method.

[0111] The rare earth element complex compound may include a dysprosium (Dy) complex compound, a terbium (Tb) complex compound, an yttrium (Y) complex compound, a La (lanthanum) complex compound, or a combination thereof.

[0112] The rare earth element complex compound may be a compound in which the rare earth element is dispersed in an organic compound such as a carbonyl compound and has an ionic form.

[0113] The use of an ionized additive component, i.e., a rare earth element complex compound, induces a uniform coating on the surface of the barium titanate-based main component, thereby ensuring a dielectric layer in which the rare earth element is uniformly distributed on the surface of the barium titanate-based main component.

[0114] The rare earth element complex compound may be mixed in an amount of 0.1 to 5 parts by mol, for example, 0.5 to 4 parts by mol, relative to 100 parts by mol of the barium titanate-based main component. When the rare earth element complex compound is mixed within the above content range, the rare earth element is uniformly coated on the surface of the barium titanate-based main component.

[0115] The dielectric slurry can be prepared by additionally mixing additives such as a dispersant, a binder, a plasticizer, a lubricant, an antistatic agent, and a solvent in addition to the obtained dielectric powder.

[0116] The dispersant may include, for example, a phosphate-based dispersant, a polycarboxylic acid-based dispersant, or a combination thereof. The dispersant may be mixed in an amount of 0.1 to 5 parts by weight, for example, 0.3 to 3 parts by weight, based on 100 parts by weight of the barium titanate-based main component. When the dispersant is mixed within the above content range, the dispersibility of the dielectric slurry is excellent, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0117] The binder may be, for example, an acrylic resin, a polyvinyl butyl resin, a polyvinyl acetal resin, an ethyl cellulose resin, etc. The binder may be added in an amount of 0.1 to 50 parts by weight, for example, 3 to 30 parts by weight, based on 100 parts by weight of the barium titanate-based main component. When the binder is mixed within the above content range, the dispersibility of the dielectric slurry is excellent, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0118] The plasticizer may be, for example, a phthalic acid-based compound such as dioctyl phthalate, benzyl butyl phthalate, dibutyl phthalate, dihexyl phthalate, di(2-ethylhexyl) phthalate, or di(2-ethylbutyl) phthalate; an adipic acid-based compound such as dihexyl adipate or di(2-ethylhexyl) adipate; a glycol-based compound such as ethylene glycol, diethylene glycol, or triethylene glycol; or a glycol ester-based compound such as triethylene glycol dibutyrate, triethylene glycol di(2-ethylbutyrate), or triethylene glycol di(2-ethylhexanoate). The plasticizer may be added in an amount of 0.1 to 20 parts by weight, for example, 1 to 10 parts by weight, based on 100 parts by weight of the barium titanate-based main component. When the plasticizer is mixed within the above content range, the dispersibility of the dielectric slurry is excellent, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0119] The solvent may be an aqueous solvent such as water; an alcohol solvent such as ethanol, methanol, benzyl alcohol, or methoxyethanol; a glycol solvent such as ethylene glycol or diethylene glycol; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone; an ester solvent such as butyl acetate, ethyl acetate, carbitol acetate, or butyl carbitol acetate; an ether solvent such as methyl cellosolve, ethyl cellosolve, butyl ether, or tetrahydrofuran; or an aromatic solvent such as benzene, toluene, or xylene. For example, the solvent may be an alcohol solvent or an aromatic solvent in consideration of the solubility and dispersibility of various additives contained in the dielectric slurry. The solvent may be mixed in an amount of 50 parts by weight to 1000 parts by weight, for example, 100 parts by weight to 500 parts by weight, relative to 100 parts by weight of the barium titanate-based main component. When the solvent is mixed within the above content range, the dielectric slurry components can be sufficiently mixed, and the solvent can be easily removed thereafter.

[0120] A wet ball mill or stirring mill can be used to mix the dielectric slurry containing the dielectric powder in which the surface of the barium titanate-based main component is coated with a rare earth element. When using zirconia balls in a wet ball mill, wet mixing can be performed for 8 to 48 hours or 10 to 24 hours using a large number of zirconia balls with diameters of 0.1 mm to 10 mm.

[0121] The produced dielectric slurry is formed into a dielectric layer after firing.

[0122] The produced dielectric slurry can be molded into a sheet shape using a tape molding method such as a doctor blade method or a calendar roll method, for example, a head-discharging on-roll molding coater, and then the molded product can be dried to obtain a dielectric green sheet.

[0123] To form a conductive paste layer that will become an internal electrode layer after firing, a conductive paste can be manufactured by mixing a conductive powder made of a conductive metal or its alloy, a binder, and a solvent. If necessary, barium titanate powder may also be mixed in as a co-material. The co-material can suppress the sintering of the conductive powder during the firing process. The conductive paste is applied in a predetermined pattern to the surface of the dielectric green sheet by various printing methods such as screen printing or transfer methods to form a conductive paste layer.

[0124] The conductive powder may include nickel (Ni) or a nickel (Ni) alloy.

[0125] Next, the dielectric green sheets on which the internal electrode patterns are formed are laminated in a plurality of layers and pressed in the lamination direction to manufacture a dielectric green sheet laminate. At this time, the dielectric green sheets and the internal electrode patterns can be laminated so that the dielectric green sheets are located on the upper and lower surfaces of the dielectric green sheet laminate in the lamination direction.

[0126] The manufactured dielectric green sheet laminate may be optionally cut into a predetermined size by dicing or the like.

[0127] Furthermore, the dielectric green sheet laminate can be solidified and dried to remove plasticizers, etc., if necessary, and after solidification and drying, can be barrel polished using a horizontal centrifugal barrel polishing machine or the like. In barrel polishing, the dielectric green sheet laminate is placed in a barrel container together with media and polishing liquid, and unnecessary parts such as burrs generated during cutting can be polished by applying rotational motion, vibration, etc. to the barrel container. Furthermore, after barrel polishing, the dielectric green sheet laminate can be washed with a cleaning liquid such as water and dried.

[0128] The dielectric green sheet laminate can then be debindered and fired to produce a capacitor body.

[0129] The binder removal treatment conditions can be appropriately adjusted depending on the components of the dielectric layers and the internal electrode layers. For example, the temperature rise rate during the binder removal treatment may be 5°C / hour to 300°C / hour, the support temperature may be 180°C to 400°C, and the temperature maintenance time may be 0.5 hours to 24 hours. During the binder removal treatment, the atmosphere may be air or a reducing atmosphere.

[0130] The firing conditions can be appropriately adjusted depending on the main component composition of the dielectric layer and the main component composition of the internal electrodes. For example, firing can be performed at a temperature of 1100°C to 1400°C, for example, 1200°C to 1350°C. Also, firing can be performed for 0.5 hours to 8 hours, for example, 1 hour to 3 hours. Also, firing can be performed in a reducing atmosphere, for example, an atmosphere of a humidified mixed gas of nitrogen and hydrogen. When the internal electrodes contain nickel (Ni) or nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere is 1.0×10 -14 MPa~1.0×10 -10 It may be MPa.

[0131] After the firing treatment, annealing can be performed if necessary. Annealing is a treatment for reoxidizing the dielectric layer, and annealing can be performed when the firing treatment is performed in a reducing atmosphere. The conditions of the annealing treatment can also be appropriately adjusted depending on the components of the dielectric layer. For example, the temperature during annealing may be 950°C to 1150°C, the time may be 0 hours to 20 hours, and the temperature increase rate may be 50°C / hour to 500°C / hour. The annealing atmosphere may be humidified nitrogen gas (N 2 ) atmosphere, with an oxygen partial pressure of 1.0×10 -9 MPa~1.0×10 -5 It may be MPa.

[0132] In the binder removal treatment, firing treatment, or annealing treatment, a wetter or the like can be used to wet the nitrogen gas or mixed gas, and in this case, the water temperature can be 5° C. to 75° C. The binder removal treatment, firing treatment, and annealing treatment can be performed consecutively or independently.

[0133] Optionally, the third and fourth faces of the manufactured capacitor body 110 may be subjected to surface treatment such as sandblasting, laser irradiation, barrel polishing, etc. By performing such surface treatment, ends of the first and second internal electrodes are exposed on the outermost surfaces of the third and fourth faces, which may improve electrical connection between the first and second external electrodes and the first and second internal electrodes, making it easier to form an alloy part.

[0134] Then, an external electrode is formed on one surface of the manufactured capacitor body 110 .

[0135] As an example, a sintered metal layer can be formed by applying a paste for forming a sintered metal layer as an external electrode and then sintering the applied paste.

[0136] The paste for forming the sintered metal layer may include a conductive metal and glass. The conductive metal and glass are the same as those described above, and therefore will not be described again. The paste for forming the sintered metal layer may selectively include a binder, a solvent, a dispersant, a plasticizer, an oxide powder, and the like. The binder may be, for example, ethyl cellulose, acrylic, butyral, and the solvent may be, for example, an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, or an aqueous solvent.

[0137] The paste for forming a sintered metal layer can be applied to the outer surface of the capacitor body 110 using various printing methods such as a dipping method, screen printing, etc., a coating method using a dispenser, a spraying method using a spray, etc. The paste for forming a sintered metal layer is applied to at least the third and fourth surfaces of the capacitor body 110, and can also be selectively applied to a part of the first, second, fifth, or sixth surface on which the band portions of the first and second external electrodes are formed.

[0138] Thereafter, the capacitor body 110 on which the paste for forming a sintered metal layer has been applied is dried and sintered at a temperature of 700° C. to 1000° C. for 0.1 to 3 hours to form a sintered metal layer.

[0139] Alternatively, a conductive resin layer forming paste may be applied to the outer surface of the obtained capacitor body 110 and then cured to form a conductive resin layer.

[0140] The paste for forming the conductive resin layer may include a resin, and optionally a conductive metal or a non-conductive filler. The conductive metal and the resin are the same as those described above, and therefore will not be described again. The paste for forming the conductive resin layer may optionally include a binder, a solvent, a dispersant, a plasticizer, an oxide powder, etc. Examples of the binder include ethyl cellulose, acrylic, butyral, etc., and the solvent may be an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, etc., or an aqueous solvent.

[0141] As an example, the conductive resin layer may be formed by dipping the capacitor body 110 into a paste for forming the conductive resin layer and then curing it, or by printing the paste for forming the conductive resin layer on the surface of the capacitor body 110 using a screen printing method or a gravure printing method, or by applying the paste for forming the conductive resin layer on the surface of the capacitor body 110 and then curing it.

[0142] Next, a plating layer is formed on the outer side of the conductive resin layer.

[0143] For example, the plating layer may be formed by a plating method, such as sputtering or electric deposition.

[0144] The above-mentioned embodiments will be described in more detail with reference to the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the invention. EXAMPLES

[0145] (Manufacturing multilayer ceramic capacitors) Example 1 Barium titanate powder and an ionic dysprosium (Dy) carbonyl compound were mixed in an amount of 3 mol parts per 100 mol parts of the barium titanate powder to prepare a dielectric powder in which the surface of the barium titanate powder was coated with Dy.

[0146] The produced dielectric powder was mixed to produce a dielectric slurry. The mixing was carried out using a zirconium ball (ZrO- 2 The mixture was mixed with ethanol / toluene and a wetting dispersant, polyvinyl butyral (PVB) resin as a binder, using a 100% alcohol-based ball as a dispersion medium, and then mechanically milled.

[0147] The prepared dielectric slurry was used in a head-discharging on-roll forming coater to prepare a dielectric green sheet.

[0148] A conductive paste layer containing nickel (Ni) was printed on the surface of a dielectric green sheet, and the dielectric green sheets (width x length x height = 3.2 mm x 2.5 mm x 2.5 mm) on which the conductive paste layer was formed were stacked and pressed to produce a dielectric green sheet laminate.

[0149] The dielectric green sheet laminate is subjected to a plasticization process at 400°C or less in a nitrogen atmosphere, and then sintered at a temperature of 1300°C or less and a hydrogen concentration of 1.0%. 2 It was fired under the following conditions.

[0150] Then, a multilayer ceramic capacitor was manufactured through processes such as forming external electrodes and plating.

[0151] Comparative Example 1 Barium titanate powder, and dysprosium oxide (Dy 2 O 3 The dielectric slurry was prepared by mixing 3 parts by mole of zirconium balls (ZrO 2 The mixture was mixed with ethanol / toluene and a wetting dispersant, polyvinyl butyral (PVB) resin as a binder, using a 100% alcohol-based ball as a dispersion medium, and then mechanically milled.

[0152] A multilayer ceramic capacitor was manufactured in the same manner as in Example 1 using the prepared dielectric slurry.

[0153] Evaluation 1: TEM-EDS analysis The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were subjected to TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) analysis, and the results are shown in FIGS.

[0154] The TEM-EDS analysis was performed as follows. The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were immersed in an epoxy mixture and cured, and then the W-axis and T-axis directions (WT directions) of the capacitor body 110 were polished to a depth of 1 / 2 in the L-axis direction, and then fixed and held in a vacuum atmosphere chamber to obtain a cross-sectional sample so that the active area where the dielectric layers and the internal electrode layers intersect could be observed. The active area of ​​the cross-sectional sample was measured using a TEM. The TEM was performed using a Xe-FIB (focused ion beam) at an acceleration voltage of 200 kV in an area of ​​about 1.3 μm×1.3 μm where at least one layer of the dielectric layer 111 was visible in the active area, and the results are shown in FIGS. 5 and 7.

[0155] As shown in Figures 6 and 8, which are transmission electron microscope (TEM) images of the measured cross-sectional sample, EDS analysis was performed on five core and five shell points of each dielectric grain in one dielectric layer. The EDS analysis was used to determine the arithmetic mean values ​​of the Dy / Ba atomic ratio and the Dy / Ti atomic ratio at the five core points and the arithmetic mean values ​​of the Dy / Ba atomic ratio and the Dy / Ti atomic ratio at the five shell points, and the results are shown in Tables 1 and 2 below.

[0156] Fig. 5 is a low-magnification TEM image of the dielectric layer according to Example 1, and Fig. 6 is a high-magnification TEM image of the dielectric layer according to Example 1. Fig. 7 is a low-magnification TEM image of the dielectric layer according to Comparative Example 1, and Fig. 8 is a high-magnification TEM image of the dielectric layer according to Comparative Example 1.

[0157] Table 1 below shows the EDS analysis results for the dielectric layers of the multilayer ceramic capacitor according to Example 1, and Table 2 below shows the EDS analysis results for the dielectric layers of the multilayer ceramic capacitor according to Comparative Example 1.

[0158] [Table 1]

[0159] [Table 2]

[0160] Referring to Figures 5 and 7, in the case of Example 1 according to one embodiment, i.e., in the case of Example 1 manufactured by a coating method using ionized rare earth elements, it can be seen that rare earth elements such as dysprosium (Dy) are uniformly distributed on the surface of barium titanate within the shell portion.

[0161] Also, from Tables 1 and 2, it can be seen that the rare earth element (R) / Ba atomic ratio variation coefficient and the rare earth element (R) / Ti atomic ratio variation coefficient in the shell part are all less than 0.19 in Example 1. On the other hand, it can be seen that the R / Ba atomic ratio variation coefficient and the R / Ti atomic ratio variation coefficient in the shell part are all 0.19 or more in Comparative Example 1. This shows that the dielectric layer of the multilayer ceramic capacitor according to an embodiment has rare earth elements uniformly distributed on the surface of barium titanate.

[0162] In addition, in the case of Example 1, which was manufactured using a coating method using ionized rare earth elements according to one embodiment, it was confirmed that the rare earth elements were internally diffused, and more rare earth elements such as dysprosium (Dy) were observed in the core portion than in Comparative Example 1.

[0163] Rating 2: Reliability The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were subjected to high temperature stress reliability (HALT) measurement, and the results are shown in FIGS.

[0164] Specifically, 76 multilayer ceramic capacitors each manufactured in Example 1 and Comparative Example 1 were prepared and mounted on a measurement board, and the high temperature stress reliability (HALT) was measured under the conditions of 105°C, 12 hours, and 9.45V using an ESPEC (PV-222, HALT) device.

[0165] FIG. 9 is a graph showing the high-temperature stress reliability of the multilayer ceramic capacitor according to Example 1, and FIG. 10 is a graph showing the high-temperature stress reliability of the multilayer ceramic capacitor according to Comparative Example 1.

[0166] 9 and 10, it can be seen that in one embodiment, Example 1, in which the coefficient of variation of the R / Ba atomic ratio and the coefficient of variation of the R / Ti atomic ratio in the shell portion are less than 0.19, has superior high-temperature stress reliability compared to Comparative Example 1.

[0167] Although a preferred embodiment of the present invention has been described above, the present invention is not limited thereto, and can be embodied in various modified forms within the scope of the claims, the description of the invention, and the accompanying drawings, which of course also fall within the scope of the present invention. [Explanation of symbols]

[0168] 100: Multilayer ceramic capacitor 110: Capacitor body 111: Dielectric layer 121: 1st internal electrode 122:Second internal electrode 131: 1st external electrode 132:Second external electrode 10: Dielectric grain 11: Core section 12: Shell part

Claims

1. a capacitor body including a dielectric layer and an internal electrode layer; an external electrode disposed on an outer side of the capacitor body; the dielectric layer includes a plurality of dielectric grains; the dielectric crystal grains include a core portion and a shell portion surrounding at least a portion of the core portion, The shell portion includes a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof; The coefficient of variation (CV) of the R / Ba atomic ratio and the coefficient of variation (CV) of the R / Ti atomic ratio in the shell portion, which are calculated by the following Equation 1, are more than 0 and less than 0.

19. [Formula 1] Coefficient of variation of atomic ratio (CV) = {standard deviation of atomic ratio (σ) / average of atomic ratio} (In the above formula 1, the standard deviation (σ) of the atomic ratio is the square root of the mean of the squares of the deviations.)

2. The rare earth element in the shell portion includes dysprosium (Dy), 2. The multilayer ceramic capacitor according to claim 1, wherein the Dy / Ba atomic ratio variation coefficient and the Dy / Ti atomic ratio variation coefficient in the shell portion obtained by Equation 1 are greater than 0 and less than 0.

19.

3. 2. The multilayer ceramic capacitor according to claim 1, wherein the R / Ba atomic ratio in the shell portion is 0.015 to 0.

02.

4. The rare earth element in the shell portion includes dysprosium (Dy), 2. The multilayer ceramic capacitor according to claim 1, wherein the Dy / Ba atomic ratio in the shell portion is 0.015 to 0.

02.

5. 2. The multilayer ceramic capacitor according to claim 1, wherein the R / Ti atomic ratio in the shell portion is 0.012 to 0.

02.

6. The rare earth element in the shell portion includes dysprosium (Dy), 2. The multilayer ceramic capacitor according to claim 1, wherein the Dy / Ti atomic ratio in the shell portion is 0.012 to 0.

02.

7. 2. The multilayer ceramic capacitor according to claim 1, wherein the core portion includes a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof.

8. 8. The multilayer ceramic capacitor according to claim 7, wherein the R / Ba atomic ratio in the core portion is 0.005 to 0.

01.

9. The rare earth element in the core portion includes dysprosium (Dy), 8. The multilayer ceramic capacitor according to claim 7, wherein the Dy / Ba atomic ratio in the core portion is 0.005 to 0.

01.

10. 8. The multilayer ceramic capacitor according to claim 7, wherein the R / Ti atomic ratio in the core portion is 0.004 to 0.

01.

11. The rare earth element in the core portion includes dysprosium (Dy), 8. The multilayer ceramic capacitor according to claim 7, wherein the Dy / Ti atomic ratio in the core portion is 0.004 to 0.

01.

12. A step of preparing a dielectric powder in which the surface of a barium titanate-based main component is coated with a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum) or a combination thereof; preparing a dielectric green sheet using a dielectric slurry containing the dielectric powder, and forming a conductive paste layer on a surface of the dielectric green sheet; laminating the dielectric green sheets having the conductive paste layers formed thereon to manufacture a dielectric green sheet laminate; sintering the dielectric green sheet laminate to manufacture a capacitor body including dielectric layers and internal electrode layers; forming an external electrode on one surface of the capacitor body; the dielectric layer includes a plurality of dielectric grains including a core portion and a shell portion surrounding at least a portion of the core portion; The shell portion includes a barium titanate-based main component including barium (Ba) and titanium (Ti), and a rare earth element (R) including dysprosium (Dy), terbium (Tb), yttrium (Y), La (lanthanum), or a combination thereof; In the shell portion, the coefficient of variation (CV) of the R / Ba atomic ratio and the coefficient of variation (CV) of the R / Ti atomic ratio obtained by the following Formula 1 are more than 0 and less than 0.

19. [Formula 1] Coefficient of variation of atomic ratio (CV) = {standard deviation of atomic ratio (σ) / average of atomic ratio} (In the above formula 1, the standard deviation (σ) of the atomic ratio is the square root of the mean of the squares of the deviations.)

13. The method of claim 12, wherein the step of preparing the dielectric powder comprises mixing a barium titanate-based main component and a rare earth complex compound.

14. 14. The method for producing a multilayer ceramic capacitor according to claim 13, wherein the rare earth element complex compound includes a dysprosium (Dy) complex compound, a terbium (Tb) complex compound, an yttrium (Y) complex compound, a La (lanthanum) complex compound, or a combination thereof.

15. The method for producing a multilayer ceramic capacitor according to claim 13, wherein the rare earth element complex compound is mixed in an amount of 0.1 to 5 parts by mol with respect to 100 parts by mol of the barium titanate-based main component.

Images