Dielectric powder, method for manufacturing the same, and multilayer ceramic capacitor containing the same

Abstract

This invention provides a dielectric powder in which core damage to the dielectric matrix is ​​minimized. [Solution] A dielectric powder comprising: a core containing barium (Ba) and titanium (Ti); a first layer disposed on at least a portion of the core; and a second layer disposed on at least a portion of the first layer; wherein at least one of the first and second layers contains one or more first elements selected from silicon (Si) and aluminum (Al), and the first and second layers contain one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn); a multilayer ceramic capacitor utilizing this; and a method for manufacturing the same.

Description

【Technical Field】 【0001】 The present disclosure relates to a dielectric powder, a method for manufacturing the same, and a multilayer ceramic capacitor including the same. 【Background Art】 【0002】 As electronic components using ceramic materials, there are capacitors, inductors, piezoelectric elements, varistors, thermistors, and the like. Among such ceramic electronic components, a multilayer ceramic capacitor (MLCC) can be used in various electronic devices due to its advantages of being small in size, having a high capacitance, and being easy to mount. 【0003】 For example, a multilayer ceramic capacitor (MLCC) can be used as a chip-shaped capacitor that is mounted on the substrates of various electronic products such as liquid crystal display devices (LCDs), plasma display panel (PDP) panels, organic light-emitting diode (OLED) video devices, computers, personal mobile terminals, and smartphones, and serves to charge or discharge electricity. 【0004】 In recent years, with the miniaturization of multilayer ceramic capacitors, the importance of reducing the particle size of the dielectric base powder and the distribution of additives has increased. 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 One embodiment provides a dielectric powder with minimized core damage to the dielectric base material. 【0006】 Another embodiment provides a method for manufacturing the dielectric powder. 【0007】 Another embodiment provides a multilayer ceramic capacitor with excellent temperature characteristics and reliability. [Means for solving the problem] 【0008】 One embodiment provides a dielectric powder comprising: a core containing barium (Ba) and titanium (Ti); a first layer disposed on at least a portion of the core; and a second layer disposed on at least a portion of the first layer, wherein at least one of the first and second layers contains one or more first elements selected from silicon (Si) and aluminum (Al), and the first and second layers contain one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). 【0009】 The first and second layers contain tin (Sn), and when TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) line analysis is performed on a linear section from the center of the dielectric powder to either boundary, the first layer may be a region where the tin (Sn) is present in an amount of 0.2 moles or more per 100 moles of titanium (Ti), while the core and the second layer may be regions where the tin (Sn) is present in an amount of less than 0.2 moles per 100 moles of titanium (Ti). 【0010】 The content of the second element may be even higher in the first layer than in the second layer. 【0011】 The first layer and the second layer may contain the first element. 【0012】 The first and second layers may contain the second element in oxide form. 【0013】 At least one of the first and second layers contains silicon (Si), and the first and second layers may contain tin (Sn). 【0014】 The first and second layers may contain silicon (Si) and tin (Sn). 【0015】 Another embodiment provides a multilayer ceramic capacitor utilizing the dielectric powder, comprising a capacitor body including a dielectric layer and an internal electrode layer, and an external electrode disposed outside the capacitor body, wherein the dielectric layer includes a plurality of dielectric grains and grain boundaries disposed between the plurality of dielectric grains, and at least one of the plurality of dielectric grains has a core-shell structure including a core portion and a shell portion disposed on at least a part of the core portion, and the shell portion and the grain boundaries include one or more first elements selected from silicon (Si) and aluminum (Al), and one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). 【0016】 In the shell portion, the molar ratio of the second element to the first element may be greater than 0.15 and less than 1.0. 【0017】 The molar ratio of the second element contained in the shell portion to the second element contained in the grain boundary may be 2.0 or more and less than 6.0. 【0018】 The core portion may include barium (Ba) and titanium (Ti). 【0019】 The shell portion and the grain boundaries may contain silicon (Si) and tin (Sn). 【0020】 Another embodiment provides a method for producing the dielectric powder, comprising the steps of: adding a metal alkoxide compound to a solution containing a barium titanate compound and subjecting it to hydrothermal treatment to primary coat the surface of the barium titanate compound with the metal alkoxide compound; and adding a metal oxide after the primary coating and subjecting it to hydrothermal treatment to secondary coat the surface of the metal alkoxide compound with the metal oxide, wherein the metal alkoxide compound comprises one or more metals selected from silicon (Si) and aluminum (Al), and the metal oxide comprises one or more metals selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn), providing a method for producing dielectric powder. 【0021】 The metal alkoxide compound may include one or more selected from tetraethyl orthosilicate (TEOS), aluminum isopropoxide, and aluminum ethoxide. 【0022】 The metal alkoxide compound can be added in an amount such that the metal of the metal alkoxide compound is 0.1 to 1 mole part per 100 mole parts of the barium titanate compound. 【0023】 The metal oxide may include one or more selected from tin oxide (SnO2), copper oxide (CuO), iron oxide (FeO, Fe3O4, Fe2O3), zinc oxide (ZnO), and manganese dioxide (MnO2). 【0024】 The metal oxide can be added in an amount such that the metal content of the metal oxide is 0.1 to 3 moles per 100 moles of the barium titanate-based compound. 【0025】 In the step of primary coating, the hydrothermal treatment can be carried out at a temperature of 100°C to 300°C. 【0026】 In the step of performing the secondary coating, the hydrothermal treatment can be performed at a temperature of 150°C to 350°C. 【Effects of the Invention】 【0027】 The dielectric powder according to one embodiment can minimize the core damage of the dielectric base material due to the doping of the additive. A multilayer ceramic capacitor to which such a dielectric powder is applied can improve temperature characteristics and reliability. 【Brief Description of the Drawings】 【0028】 [Figure 1] It is a schematic diagram showing the dielectric powder according to one embodiment. [Figure 2] It is a perspective view showing a multilayer ceramic capacitor according to one embodiment. [Figure 3] It is a cross-sectional view of the multilayer ceramic capacitor cut along the I-I' line in FIG. 2. [Figure 4] It is a cross-sectional view of the multilayer ceramic capacitor cut along the II-II' line in FIG. 2. [Figure 5] It is an exploded perspective view showing the laminated structure by disassembling the capacitor body in FIG. 2. [Figure 6] It is a schematic diagram showing the dielectric layer according to one embodiment. [Figure 7A] It is an HR-TEM (High-Resolution Transmission Electron Microscope) analysis image of the dielectric powder according to Production Example 1. [Figure 7B] It is an IFFTHR-TEM (Inverse Fourier Transform High-Resolution Transmission Electron Microscope) analysis image of the dielectric powder according to Production Example 1. [Figure 8] It is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of the dielectric powder according to Production Example 1. [Figure 9] It is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) line analysis image of the dielectric powder according to Production Example 1. [Figure 10] This is an image of the TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) mapping analysis of the dielectric layer according to Example 1. [Figure 11] This is a TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) line analysis image of the dielectric layer according to Example 1. [Figure 12] This graph shows the reliability of the multilayer ceramic capacitor according to Example 1. [Figure 13] This graph shows the reliability of the multilayer ceramic capacitor related to Comparative Example 1. [Modes for carrying out the invention] 【0029】 Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those with ordinary skill in the art to which the present invention pertains can easily implement it. In order to clearly illustrate the present invention in the drawings, unnecessary parts have been omitted, and the same or similar components are given the same reference numerals throughout the specification. In addition, some components in the attached drawings are exaggerated, omitted, or shown schematically, and the size of each component does not fully reflect its actual size. 【0030】 The accompanying drawings are provided for the purpose of easily understanding the embodiments disclosed herein and should not be understood as limiting the technical ideas disclosed herein, but rather as including all modifications, equivalents, or substitutions that fall within the concept and scope of the invention. 【0031】 Terms including ordinal numbers, such as "first," "second," etc., can be used to describe various components, but the components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from another. 【0032】 Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on top of" or "above" another part, this includes not only when it is "directly above" the other part, but also when there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, being "on top of" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on top of" or "above" in the opposite direction to gravity. 【0033】 Throughout the specification, terms such as “includes” or “have” should be understood as indicating the presence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, without prejudice to the possibility of the presence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof. Therefore, when a part “includes” a component, this means, unless otherwise stated, that it may include other components rather than excluding them. 【0034】 Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly. 【0035】 Furthermore, throughout the specification, the term "connected" does not only mean that two or more components are directly connected, but can also mean that two or more components are indirectly connected through other components, that they are not only physically connected but also electrically connected, or that they are integrated by location or function, even if they are referred to by different names. 【0036】 Furthermore, throughout the specification, when it says "included as a main component," this means that of the at least one component present in a given area, one component has the highest content relative to the total amount of components. 【0037】 A dielectric powder according to one embodiment will be described with reference to Figure 1. 【0038】 Figure 1 is a schematic diagram showing a dielectric powder according to one embodiment. 【0039】 Referring to Figure 1, a dielectric powder 10 according to one embodiment may include a core 11, a first layer 12 disposed on at least a portion of the core, and a second layer 13 disposed on at least a portion of the first layer 12. For example, the first layer 12 is disposed on the entire surface of the core 11, and the second layer 13 is disposed on the entire surface of the first layer 12. 【0040】 In Figure 1, the structure is illustrated in which the first layer 12 surrounds the entire core 11 and the second layer 13 surrounds the entire first layer 12. However, this is merely one example of a dielectric powder structure and is not limited to this. 【0041】 The core 11 may contain barium (Ba) and titanium (Ti). At least one of the first layer 12 and the second layer 13 may contain one or more first elements selected from silicon (Si) and aluminum (Al), and the first layer 12 and the second layer 13 may contain one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). 【0042】 The components of the core 11 are derived from a barium titanate-based compound, which is the dielectric matrix, and the components of the first layer 12 and the second layer 13 are derived from additives. That is, the additives dope the double-layer structure of the first layer 12 and the second layer 13 on at least a portion of the core 11, thereby minimizing damage to the core due to doping with the additives. Therefore, a dielectric powder having the above structure and components can improve the dielectric temperature characteristics. 【0043】 The first element, which is included in at least one of the first layer 12 and the second layer 13, may include, for example, silicon (Si). Alternatively, as an example, the first element may be included in both the first layer 12 and the second layer 13. 【0044】 The second element contained in the first layer 12 and the second layer 13 originates from an internal diffusion additive and may include, for example, tin (Sn). 【0045】 The second element may be present in a higher content in the first layer 12 than in the second layer 13. When the content of the second element, such as Sn, is higher in the first layer 12 than in the second layer 13, the diffusion of the additive by-components into the dielectric crystal grains can be suppressed, thereby improving the temperature characteristics of the dielectric. 【0046】 The second element can exist in oxide form in the first layer 12 and the second layer 13. 【0047】 For example, at least one of the first layer 12 and the second layer 13 may contain silicon (Si), and both the first layer 12 and the second layer 13 may contain tin (Sn). 【0048】 As a further example, both the first layer 12 and the second layer 13 may contain silicon (Si) and tin (Sn). 【0049】 The structure of the dielectric powder 10 can be confirmed by HR-TEM (high-resolution transmission electron microscope) or IFFTHR-TEM (inverse Fourier transform high-resolution transmission electron microscope) analysis. 【0050】 Specifically, the dielectric powder 10 can be measured using HR-TEM or IFFTHR-TEM under conditions of an acceleration voltage of 200kV and a magnification of 630k. The core 11, the first layer 12, and the second layer 13 can be distinguished and identified through the measured image. 【0051】 Furthermore, the structure and composition of the dielectric powder 10 can also be confirmed by TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy). 【0052】 Specifically, the dielectric powder 10 can be measured using a TEM (transmission electron microscope) under conditions of an acceleration voltage of 200kV and a magnification of 630k. Energy-dispersive spectroscopy (EDS) analysis can then be performed on the measured TEM image to confirm the structure and composition of the dielectric powder. Furthermore, EDS line analysis can be performed on a straight section from the center of the dielectric powder to either boundary using the measured TEM image to confirm the composition of the dielectric powder. 【0053】 For example, when the first layer 12 and the second layer 13 contain Sn, when performing TEM-EDS line analysis on a straight section from the center of the dielectric powder to either boundary, the core 11, the first layer 12, and the second layer 13 can be distinguished based on the point where the amount of Sn is 0.2 moles relative to 100 moles of Ti. That is, the first layer 12 can be defined as the region where the amount of Sn is 0.2 moles or more relative to 100 moles of Ti, and the core 11 and the second layer 13 can be defined as the region where the amount of Sn is less than 0.2 moles relative to 100 moles of Ti. The internal region toward the center of the dielectric powder relative to the first layer 12 can be defined as the core 11, and the external region toward the outside relative to the first layer 12 can be defined as the second layer 13. 【0054】 The dielectric powder mentioned above can be manufactured by the following method. 【0055】 It can be manufactured by the following steps: adding a metal alkoxide compound to a solution containing a barium titanate compound and performing a hydrothermal treatment to primary coat the surface of the barium titanate compound with the metal alkoxide compound; and adding a metal oxide after the primary coating and performing a hydrothermal treatment to secondary coat the surface of the metal alkoxide compound with the metal oxide. 【0056】 Barium titanate compounds are compounds containing barium (Ba) and titanium (Ti), and may include one or more selected from, for example, BaTiO3, Ba(Ti,Zr)O3, Ba(Ti,Sn)O3, (Ba,Ca)TiO3, (Ba,Ca)(Ti,Ca)O3, (Ba,Ca)(Ti,Zr)O3, (Ba,Ca)(Ti,Sn)O3, (Ba,Sr)TiO3, (Ba,Sr)(Ti,Zr)O3, and (Ba,Sr)(Ti,Sn)O3. 【0057】 The metal alkoxide compound may be an alkoxide compound containing one or more metals selected from silicon (Si) and aluminum (Al). In one embodiment of the dielectric powder 10, the first element may be derived from the metal alkoxide compound that is primary coated on the surface of the barium titanate compound. 【0058】 The metal oxide may be an oxide containing one or more metals selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). In one embodiment of the dielectric powder 10, the second element may be derived from the metal oxide that is secondary-coated on the surface of the primary-coated metal alkoxide compound. 【0059】 According to a method for manufacturing dielectric powder according to one embodiment, a first layer is formed as a barrier layer that prevents the movement of internal diffusion additives corresponding to the metal oxide to be secondary coated by primary coating a metal alkoxide compound on the surface of the barium titanate compound. Furthermore, by secondary coating a metal oxide on the surface of the primary coated metal alkoxide compound, a second layer is additionally formed on the first barrier layer as a barrier layer corresponding to the internal diffusion additive layer, thereby minimizing damage to the core. In other words, by forming a double additive layer, core damage due to additive doping can be minimized, and the temperature characteristics of the dielectric can be easily ensured. 【0060】 Specifically, the primary coating can be formed by adding a metal alkoxide compound to a solution containing barium titanate compound powder after grain growth is complete, and then forming a first layer as a barrier layer on the powder surface through a dissolution and reprecipitation process. That is, after hydrolysis of the added metal alkoxide compound, reaction products with Ba and Ti are precipitated on the surface of the barium titanate compound through polymerization and neutralization reactions, thereby forming a coating layer. 【0061】 The solution containing the barium titanate compound may be an aqueous solution or an organic solution, for example, an aqueous solution. In the case of an aqueous solution, for example, it may be a solution with a pH higher than 7. 【0062】 The metal alkoxide compound may include one or more selected from, for example, tetraethyl orthosilicate (TEOS), aluminum isopropoxide, and aluminum ethoxide. 【0063】 The metal alkoxide compound can be added in a content where the metal of the metal alkoxide compound is 0.1 to 1 mole part per 100 mole parts of the barium titanate compound, for example, the metal such as Si can be added in a content of 0.1 to 0.8 mole parts or 0.2 to 0.6 mole parts. When the metal alkoxide compound is added within the above content range, a first layer can be easily formed as a barrier layer that prevents the movement of internal diffusion additives. 【0064】 In the primary coating step, the hydrothermal treatment can be performed at a temperature of 100°C to 300°C, for example, 150°C to 250°C. When the hydrothermal treatment is performed within this temperature range during primary coating, the metal alkoxide compound is stably hydrolyzed, allowing for easy primary coating of the barium titanate compound onto its surface. 【0065】 Furthermore, during the primary coating step, the temperature can be maintained and the mixture stirred for a certain period of time, for example, more than 30 minutes, to ensure sufficient hydrolysis of the metal alkoxide compound. The reaction time and temperature can also be adjusted depending on the amount and type of metal alkoxide compound added, and the reaction temperature may be below the temperature required for grain growth of the barium titanate compound. 【0066】 Furthermore, for the secondary coating, a second barrier layer can be formed on the powder surface by adding a metal oxide to a solution containing barium titanate-based compound powder, which has a first barrier layer formed in the primary coating, and then dissolving and reprecipitation the metal oxide through a dissolution and reprecipitation process. 【0067】 The metal oxide may include one or more selected from, for example, tin oxide (SnO2), copper oxide (CuO), iron oxide (FeO, Fe3O4, Fe2O3), zinc oxide (ZnO), and manganese dioxide (MnO2). The metal oxide can be used, for example, in the form of a sol solution in which the metal oxide is dispersed in a basic solvent. 【0068】 The metal oxide can be added in a content of 0.1 to 3 moles of metal per 100 moles of barium titanate compound, for example, 0.2 to 2.5 moles or 0.5 to 2.0 moles of metal such as Sn. When the metal oxide is added within the above content range, a second layer of internal diffusion additive is easily formed on the first layer, thereby minimizing damage to the core. 【0069】 In the secondary coating step, the hydrothermal treatment can be performed at a temperature of 150°C to 350°C, for example, at a temperature of 200°C to 300°C. When the hydrothermal treatment is performed within this temperature range during secondary coating, the metal oxide dissolves stably and re-deposits, allowing for easy secondary coating of the barium titanate compound surface. 【0070】 Furthermore, in the secondary coating step, the temperature can be maintained and the mixture stirred for a certain period of time, for example, more than 2 hours, to ensure sufficient dissolution of the metal oxide. The reaction time and temperature can also be adjusted depending on the amount and type of metal oxide added, and the reaction temperature may be below the temperature required for grain growth of the barium titanate compound. 【0071】 The multilayer ceramic capacitors using the dielectric powder mentioned above will be explained below with reference to Figures 2 to 5. 【0072】 Figure 2 is a perspective view showing a multilayer ceramic capacitor according to one embodiment; Figure 3 is a cross-sectional view of the multilayer ceramic capacitor cut along the line I-I' in Figure 2; Figure 4 is a cross-sectional view of the multilayer ceramic capacitor cut along the line II-II' in Figure 2; and Figure 5 is an exploded perspective view showing the multilayer structure when the capacitor body of Figure 2 is disassembled. 【0073】 The L-axis, W-axis, and T-axis shown in Figures 2 to 5 represent the length, width, and thickness directions of the capacitor body 110, respectively. Here, the thickness direction (T-axis direction) may be perpendicular to the broad surface (main surface) of the sheet-shaped component, and can be used in the same way as the stacking direction in which the dielectric layer 111 is stacked, for example. The length direction (L-axis direction) is a direction that extends alongside the broad surface (main surface) of the sheet-shaped component and can be approximately perpendicular to the thickness direction (T-axis direction), and may 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) is a direction that extends alongside the broad surface (main surface) of the sheet-shaped component and may be approximately perpendicular to the thickness direction (T-axis direction) and the length direction (L-axis direction), and the length in the length direction (L-axis direction) of the sheet-shaped component may be longer than the length in the width direction (W-axis direction). 【0074】 Referring to Figures 2 to 5, a multilayer ceramic capacitor 100 according to one embodiment includes a capacitor body 110 and external electrodes 131 and 132 disposed outside the capacitor body 110. The external electrodes 131 and 132 may include a first external electrode 131 and a second external electrode 132 disposed at opposing ends of the capacitor body 110 in the longitudinal direction (L-axis direction). 【0075】 The capacitor body 110 may, for example, have a roughly hexahedral shape. 【0076】 For the convenience of explaining 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 and second surfaces, the two surfaces connected to the first and second surfaces that face each other in the length direction (L-axis direction) are defined as the third and fourth surfaces, and the two surfaces connected to the first and second surfaces that face each other in the width direction (W-axis direction) are defined as the fifth and sixth surfaces. 【0077】 For example, the first surface, which is the bottom surface, is the surface facing the mounting direction. Also, the first to sixth surfaces are flat, but one embodiment is not limited to this. For example, the first to sixth surfaces may be curved surfaces with a convex central portion, and the corners that form the boundaries of each surface may be rounded. 【0078】 The shape, size, and number of dielectric layers 111 of the capacitor body 110 are not limited to those shown in the drawings of this embodiment. 【0079】 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 a first internal electrode layer 121 and a second internal electrode layer 122 that are alternately arranged in the thickness direction (T-axis direction) between the dielectric layers 111. 【0080】 At this time, the boundaries between adjacent dielectric layers 111 of the capacitor body 110 can be integrated to such an extent that they are difficult to confirm without using a scanning electron microscope (SEM). 【0081】 The capacitor body 110 may include an active region and cover regions 112, 113. 【0082】 The active region is a region in which the dielectric layer 111 and the internal electrode layers 121 and 122 are alternately stacked, and is the part that contributes to the capacitance formation of the multilayer ceramic capacitor 100. Specifically, the active region may be a region in which the first internal electrode layer 121 or the second internal electrode layer 122, which are stacked along the thickness direction (T-axis direction), are superimposed (overlapped). 【0083】 The cover regions 112 and 113 can be positioned as thickness-direction margins on the first and second surfaces of the active region in the thickness direction (T-axis direction), respectively. Such cover regions 112 and 113 may be formed by a single dielectric layer 111 or by two or more dielectric layers 111 being laminated on the upper and lower surfaces of the active region, respectively. 【0084】 Furthermore, the capacitor body 110 may also include a side margin region. 【0085】 The side margin region can be located as a widthwise margin portion at the opposite ends of the active region in the widthwise direction (W-axis direction), i.e., on the fifth and sixth surfaces, respectively. The side margin region is formed by applying a conductive paste layer for the internal electrode layer to the surface of the dielectric green sheet, applying the conductive paste layer only to a portion of the surface of the dielectric green sheet, and then stacking dielectric green sheets without the conductive paste layer on both sides of the surface of the dielectric green sheet and firing, but the formation method is not limited to this. 【0086】 The cover regions 112, 113 and the side margin regions serve to prevent damage to the internal electrode layers 121, 122 due to physical or chemical stress. 【0087】 Dielectric layer A dielectric layer according to one embodiment will be described with reference to Figure 6. 【0088】 Figure 6 is a schematic diagram showing a dielectric layer according to one embodiment. 【0089】 Referring to Figure 6, the dielectric layer 111 may include a plurality of dielectric crystal grains 20 and grain boundaries 30 arranged between the plurality of dielectric crystal grains 20. 【0090】 At least one of the multiple dielectric crystal grains 20 may have a core-shell structure including a core portion 21 and a shell portion 22 disposed on at least a part of the core portion 21. For example, the shell portion 22 is disposed on the entire surface of the core portion 21. 【0091】 The dielectric layer 111 is formed from a dielectric slurry containing the aforementioned dielectric powder. 【0092】 Specifically, the core portion 21 contains barium (Ba) and titanium (Ti), and the shell portion 22 and grain boundaries 30 may contain one or more first elements selected from silicon (Si) and aluminum (Al), and one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). When both the shell portion 22 and grain boundaries 30 contain the first and second elements, damage to the core portion due to doping of the dielectric matrix with additives can be minimized, thereby ensuring a multilayer ceramic capacitor with improved temperature characteristics and reliability. In other words, the dielectric layer 111 according to one embodiment has a structure and composition due to the diffusion control effect of the additive components by a first barrier layer formed by a coating of a metal alkoxide compound and a second barrier layer formed by a coating of a metal oxide, by utilizing the dielectric powder described above, thereby improving the temperature characteristics and reliability of the multilayer ceramic capacitor. 【0093】 The components of the core 21 can be derived from barium titanate-based compounds used as dielectric base materials during the production of the dielectric powder described above. Barium titanate-based compounds have a high dielectric constant and contribute to the formation of the dielectric constant of the multilayer ceramic capacitor 100. 【0094】 As an example, barium titanate compounds may include one or more selected from BaTiO3, Ba(Ti,Zr)O3, Ba(Ti,Sn)O3, (Ba,Ca)TiO3, (Ba,Ca)(Ti,Zr)O3, (Ba,Ca)(Ti,Sn)O3, (Ba,Sr)TiO3, (Ba,Sr)(Ti,Zr)O3, and (Ba,Sr)(Ti,Sn)O3. 【0095】 The first element may originate from a metal alkoxide compound that is primary coated onto the surface of the barium titanate compound during the production of the dielectric powder described above, and the second element may originate from a metal oxide that is secondary coated onto the surface of the primary coated metal alkoxide compound during the production of the dielectric powder. 【0096】 For example, the shell portion 22 and the grain boundary 30 may contain silicon (Si) and tin (Sn). 【0097】 The structure and composition of the dielectric layer 111 can be confirmed by TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy). TEM-EDS can be measured using the following method. 【0098】 After curing the multilayer ceramic capacitor 100 in an epoxy mixture, the W-axis and T-axis planes (WT planes) of the capacitor body 110 are polished to a depth of 1 / 2 in the L-axis direction to obtain a cross-sectional sample that allows observation of the active region where the dielectric layer 111 and the internal electrode layers 121 and 122 intersect. Subsequently, the active region of the cross-sectional sample is divided into three equal parts: the upper region, the middle region, and the lower region. Each region is then measured using a TEM (transmission electron microscope) so that at least one dielectric layer and one internal electrode layer are visible. The TEM can be measured using a Xe-FIB (focused ion beam) under conditions of an acceleration voltage of 200kV and a magnification of 450k. Subsequently, EDS (energy-dispersive spectroscopy) analysis of the dielectric layer is performed on the TEM image of the measured cross-sectional sample to confirm the structure and composition of the dielectric crystal grains 20 and grain boundaries 30 having a core-shell structure. 【0099】 At this time, the element Dy, a minor component, can also be utilized as a method to more clearly identify the core portion 21, the shell portion 22, and the grain boundaries 30. For example, when performing TEM-EDS line analysis along the long axis passing through the center of a dielectric crystal grain having the core-shell structure, the region where Dy is greater than approximately 0.3 moles per 100 moles of Ti can be defined as a grain boundary, the region where Dy is between approximately 0.15 moles and approximately 0.3 moles per 100 moles of Ti can be defined as the shell portion, and the region where Dy is less than approximately 0.15 moles per 100 moles of Ti can be defined as the core portion. 【0100】 According to one embodiment, the molar ratio of the second element to the first element in the shell portion 22 may be greater than 0.15 and less than 1.0, for example, 0.2 to 0.9, 0.3 to 0.8, or 0.4 to 0.6. When the molar ratio of the second element to the first element in the shell portion 22 is within the above range, the temperature characteristics and reliability of the multilayer ceramic capacitor can be improved by minimizing damage to the core portion due to doping of the dielectric base material with additives. 【0101】 Furthermore, the molar ratio of the second element contained in the shell portion 22 to the second element contained in the grain boundary 30 may be 2.0 or more and less than 6.0, for example, 3.0 or more and less than 6.0, or 4.0 or more and less than 6.0. When the molar ratio of the second element in the shell portion 22 to the second element in the grain boundary 30 is within the above range, the temperature characteristics and reliability of the multilayer ceramic capacitor can be improved by minimizing damage to the core portion due to doping of the dielectric base material with additives. 【0102】 In other words, in one embodiment of the dielectric layer 111, by utilizing the aforementioned dielectric powder, the first layer, which is a barrier layer formed by a coating of a metal alkoxide compound, and the second layer, which is a barrier layer formed by a coating of a metal oxide, have a diffusion control effect on the additive components, so that the additive components are present in a predetermined ratio range between the shell portion and the grain boundaries. This makes it possible to obtain a multilayer ceramic capacitor with excellent temperature characteristics and reliability. 【0103】 The molar ratio of the second element to the first element in the shell portion 22, and the molar ratio of the second element in the shell portion 22 to the second element at the grain boundary 30, can be measured as follows. 【0104】 After curing the multilayer ceramic capacitor 100 in an epoxy mixture, the W-axis and T-axis planes (WT planes) of the capacitor body 110 are polished to a depth of 1 / 2 in the L-axis direction to obtain a cross-sectional sample that allows observation of the active region where the dielectric layer 111 and the internal electrode layers 121 and 122 intersect. Subsequently, the active region of the cross-sectional sample is divided into three equal parts: the upper region, the middle region, and the lower region. Each region is then measured using a TEM (transmission electron microscope) so that at least one dielectric layer and one internal electrode layer are visible. The TEM can be measured using a Xe-FIB (focused ion beam) under conditions of an acceleration voltage of 200kV and a magnification of 450k. 【0105】 Next, in the TEM images of the upper, central, and lower regions, dielectric crystal grains having at least one core-shell structure can be selected for each region. Then, EDS line analysis can be performed on the linear interval from the center of the dielectric crystal grain to either grain boundary. For example, three dielectric crystal grains can be selected from the upper region, four from the central region, and three from the lower region, and EDS line analysis can be performed on each of the ten grains in total. 【0106】 Next, the molar ratio of the second element (E2) to the first element (E1) in the shell portion 22 can be determined by measuring the E2 / E1 molar ratio within the shell portion for each dielectric crystal grain and taking the average value for a total of 10 grains. At this time, the E2 / E1 molar ratio within the shell portion for each dielectric crystal grain can be determined by measuring the E2 / E1 molar ratio at three equally spaced points within the shell portion for a single dielectric crystal grain and taking the average value. The E2 / E1 molar ratio at each point may be the molar ratio of the E1 and E2 content measured at that point based on 100 molar parts of Ti. 【0107】 Furthermore, the molar ratio of the second element in the shell portion 22 to the second element at the grain boundary 30 can be determined by measuring the molar ratio of the second element in the shell portion to the second element at the grain boundary for each dielectric crystal grain, and then calculating the average value for a total of 10 measurements. In this case, the molar ratio of the second element in the shell portion to the second element at the grain boundary for each dielectric crystal grain can be determined by measuring the content of the second element at three equally spaced points within the shell portion and three equally spaced points within the grain boundary for a single dielectric crystal grain, measuring the molar ratio of the second element in the shell portion to the second element at the grain boundary for any three points, and then calculating the average value. In addition, the content of the second element at each point can be measured based on 100 molar parts of Ti at that point. 【0108】 In addition to the components mentioned above, the dielectric layer 111 may further contain one or more subcomponents selected from manganese (Mn), chromium (Cr), silicon (Si), aluminum (Al), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), barium (Ba), lanthanum (La), yttrium (Y), actinium (Ac), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), ruthenium (Lu), hafnium (Hf), and vanadium (V), for example, dysprosium (Dy) may be included. 【0109】 The average thickness (average length in the T-axis direction) of the dielectric layer 111 may be 0.1 μm to 8.0 μm, for example, 0.1 μm to 6.0 μm. When the average thickness of the dielectric layer 111 is within the above range, the reliability of the multilayer ceramic capacitor is excellent. 【0110】 The average thickness of the dielectric layer 111 can be measured by scanning electron microscopy (SEM) analysis after curing the multilayer ceramic capacitor 100 in an epoxy mixture, polishing it, and then ion milling it. The SEM can be used to measure under conditions such as 10kV and 100x magnification, so that at least one, three, five, or ten layers of the dielectric layer 111 are visible in the active region where the dielectric layer 111 and the internal electrode layers 121 and 122 intersect. Using the SEM image, the average thickness of the dielectric layer 111 can be determined at 10 points spaced at predetermined intervals from the midpoint of the dielectric layer 111 in the length direction (L-axis direction) or width direction (W-axis direction). The spacing of the 10 points can be adjusted by the scale of the SEM image, for example, between 1μm and 100μm, between 1μm and 50μm, or between 1μm and 10μm. In this case, all 10 points must be located within the dielectric layer 111. If all 10 points are not located within the dielectric layer 111, the position of the reference point can be changed or the spacing between the 10 points can be adjusted. Furthermore, by extending this average value measurement to 10 dielectric layers and measuring the average value, the average thickness of the dielectric layers can be more generalized. 【0111】 internal electrode layer The internal electrode layers 121 and 122, namely the first internal electrode layer 121 and the second internal electrode layer 122, are electrodes having opposite polarities and are alternately arranged facing each other along the T-axis direction with the dielectric layer 111 in between, with one end of each being exposed through the third and fourth surfaces of the capacitor body 110. 【0112】 The first internal electrode layer 121 and the second internal electrode layer 122 can be electrically insulated from each other by the dielectric layer 111 placed in between them. 【0113】 The ends of the first internal electrode layer 121 and the second internal electrode layer 122, which are alternately exposed through the third and fourth surfaces of the capacitor body 110, can be electrically connected to the first external electrode 131 and the second external electrode 132, respectively. 【0114】 The internal electrode layers 121 and 122 contain a conductive metal, and may include one or more metals and alloys thereof, such as Ni, Cu, Ag, Pd, and Au. 【0115】 Furthermore, the internal electrode layers 121 and 122 may also contain dielectric particles with the same composition as the ceramic material contained in the dielectric layer 111. 【0116】 The internal electrode layers 121 and 122 can be formed using a conductive paste containing a conductive metal. The conductive paste can be printed using screen printing or gravure printing. 【0117】 The average thickness of the internal electrode layers 121 and 122 may be 0.1 μm to 2 μm. 【0118】 The average thickness of the internal electrode layers 121 and 122 can be measured by scanning electron microscopy (SEM) analysis. Specifically, using an SEM image of a cross-sectional sample obtained in the same manner as the method for measuring the average thickness of the dielectric layer 111, the average thickness of the internal electrode layers 121 and 122 can be determined at 10 points spaced at predetermined intervals from the reference point, with the reference point being the center point in the length direction (L-axis direction) or width direction (W-axis direction) of the internal electrode layers 121 and 122. The interval between the 10 points can be adjusted by the scale of the SEM image, for example, between 1 μm and 100 μm, 1 μm and 50 μm, or 1 μm and 10 μm. In this case, all 10 points must be located within the internal electrode layers 121 and 122. If all 10 points are not located within the internal electrode layers 121 and 122, the position of the reference point can be changed or the interval between the 10 points can be adjusted. Furthermore, by extending this average value measurement to 10 internal electrode layers and measuring the average value, the average thickness of the internal electrode layers can be more generalized. 【0119】 The capacitor body 110 can be formed by firing a laminate in which multiple dielectric layers 111 and internal electrode layers 121 and 122 are stacked. 【0120】 external electrode External electrodes 131 and 132, namely the first external electrode 131 and the second external electrode 132, are supplied with voltages of different polarities from each other and can be electrically connected to the exposed portions of the first internal electrode layer 121 and the second internal electrode layer 122, respectively. 【0121】 With the above configuration, when a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charge is accumulated between the first internal electrode layer 121 and the second internal electrode layer 122, which face each other. At this time, the capacitance of the multilayer ceramic capacitor 100 is proportional to the overlapping area of ​​the first internal electrode layer 121 and the second internal electrode layer 122, which overlap each other along the T-axis in the active region. 【0122】 The first external electrode 131 and the second external electrode 132 are arranged on the third and fourth surfaces of the capacitor body 110, respectively, and may include first and second connecting portions that connect to the first internal electrode layer 121 and the second internal electrode layer 122, and first and second band portions that are arranged at the corners where the third and fourth surfaces of the capacitor body 110 meet the first and second surfaces or the fifth and sixth surfaces. 【0123】 The first and second band portions can extend to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 at the first and second connection portions, respectively. The first and second band portions can serve to improve the adhesion strength of the first external electrode 131 and the second external electrode 132. 【0124】 The external electrodes 131 and 132 may include a sintered metal layer in contact with the capacitor body 110, a conductive resin layer positioned to cover the sintered metal layer, and a plating layer positioned to cover the conductive resin layer. 【0125】 The sintered metal layer may contain conductive metals and glass. 【0126】 Conductive metals 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. If the conductive metal contains copper, other metals may be included in amounts of 5 moles or less per 100 moles of copper. 【0127】 The glass may contain a composition of mixed oxides, for example, 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). 【0128】 Selectively, the conductive resin layer can be formed on a sintered metal layer, for example, in a form that completely covers the sintered metal layer. On the other hand, the first external electrode 131 and the second external electrode 132 do not have to include a sintered metal layer, in which case the conductive resin layer can be in direct contact with the capacitor body 110. 【0129】 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., the band portion) in which the conductive resin layer extends 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., the band portion) in which the sintered metal layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. In other words, the conductive resin layer can be formed on the sintered metal layer and can be formed in a manner that completely covers the sintered metal layer. 【0130】 The conductive resin layer contains resin and conductive metal. 【0131】 The resin contained in the conductive resin layer is not particularly limited as long as it has bonding and shock-absorbing properties and can be mixed with conductive metal powder to form a paste, and may include, for example, phenolic resin, acrylic resin, silicone resin, epoxy resin, or polyimide resin. 【0132】 The conductive metal contained in the conductive resin layer serves to electrically connect with the internal electrode layers 121, 122, or the sintered metal layer. 【0133】 The conductive metal contained in the conductive resin layer may be spherical, flake-shaped, or a combination thereof. That is, the conductive metal may consist solely of flakes, solely of spheres, or a mixture of flakes and spheres. 【0134】 Here, "spherical" can include forms that are not perfectly spherical, for example, forms in which the ratio of the length of the long axis to the short axis (long axis / short axis) is 1.45 or less. "Flake powder" means powder having a flat and elongated form and is not particularly limited, but for example, the ratio of the length of the long axis to the short axis (long axis / short axis) may be 1.95 or more. 【0135】 The external electrodes 131 and 132 may further include a plating layer positioned outside the conductive resin layer. 【0136】 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), or alloys thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or a configuration in which nickel (Ni) plating layers and tin (Sn) plating layers are sequentially laminated, or a configuration in which tin (Sn) plating layers, nickel (Ni) plating layers, and tin (Sn) plating layers are sequentially laminated. The plating layer may also include multiple nickel (Ni) plating layers and / or multiple tin (Sn) plating layers. 【0137】 The plating layer can improve the mountability of the multilayer ceramic capacitor 100 on the substrate, structural reliability, durability against external elements, heat resistance, and equivalent series resistance (ESR). 【0138】 The following describes a method for manufacturing a multilayer ceramic capacitor 100 according to one embodiment. 【0139】 A multilayer ceramic capacitor 100 according to one embodiment can be manufactured by the following steps: manufacturing a dielectric slurry containing the aforementioned dielectric powder; manufacturing a dielectric green sheet using the dielectric slurry and forming a conductive paste layer on the surface of the dielectric green sheet; laminating the dielectric green sheets on which the conductive paste layer is formed to manufacture a dielectric green sheet laminate; firing the dielectric green sheet laminate to manufacture a capacitor body including a dielectric layer and an internal electrode layer; and forming an external electrode on one surface of the capacitor body. 【0140】 Dielectric powder can be manufactured by first coating the surface of a barium titanate-based compound with a metal alkoxide-based compound, as described above, and then secondarily coating the surface of the primary-coated metal alkoxide-based compound with a metal oxide. 【0141】 The dielectric slurry may further contain auxiliary component powders, i.e., auxiliary component-containing compounds. 【0142】 Compounds containing minor components may include compounds containing one or more minor components selected from manganese (Mn), chromium (Cr), silicon (Si), aluminum (Al), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), barium (Ba), lanthanum (La), yttrium (Y), actinium (Ac), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), ruthenium (Lu), hafnium (Hf), and vanadium (V). For example, compounds containing dysprosium (Dy) may be included. 【0143】 The compound containing the minor component may be at least one of the oxide, nitrate, and salt compounds of the minor component, or it may be a compound in sol form dispersed in an organic solvent. 【0144】 The compound containing the minor component may be included in an amount of 0.9 to 1.5 moles of the minor component per 100 moles of the barium titanate compound. 【0145】 Dielectric slurry can be manufactured by adding solvents and other additives such as dispersants, binders, plasticizers, lubricants, and antistatic agents. 【0146】 The dispersant may include, for example, phosphate ester-based dispersants, polycarboxylic acid-based dispersants, or combinations thereof. The dispersant may be mixed in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the barium titanate compound, for example, 0.3 to 3 parts by weight. 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. 【0147】 The binder may be, for example, an acrylic resin, polyvinyl butyl resin, polyvinyl acetal resin, or ethyl cellulose resin. The binder can be added in an amount of 0.1 to 50 parts by weight per 100 parts by weight of the barium titanate compound, for example, 3 to 30 parts by weight. 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. 【0148】 The plasticizer may be, for example, phthalate compounds such as dioctyl phthalate, benzyl butyl phthalate, dibutyl phthalate, dihexyl phthalate, di(2-ethylhexyl) phthalate, and di(2-ethylbutyl) phthalate; adipic acid compounds such as dihexyl adipic acid and bis(2-ethylhexyl) adipic acid; glycol compounds such as ethylene glycol, diethylene glycol, and triethylene glycol; or glycol ester compounds such as triethylene glycol dibutyrate, triethylene glycol di(2-ethylbutylate), and triethylene glycol di(2-ethylhexanoate). The plasticizer can be added in an amount of 0.1 to 20 parts by weight per 100 parts by weight of the barium titanate compound, for example, 1 to 10 parts by weight. 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. 【0149】 The solvent may be an aqueous solvent such as water; an alcoholic solvent such as ethanol, methanol, benzyl alcohol, or 2-methoxyethanol; a glycolic solvent such as ethylene glycol or diethylene glycol; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone; an esteric solvent such as butyl acetate, ethyl acetate, carbitol acetate, or butyl carbitol acetate; an etheric solvent such as methyl cellosolve, ethyl cellosolve, butyl ether, or tetrahydrofuran; or an aromatic solvent such as benzene, toluene, or xylene. The solvent can be an alcoholic or aromatic solvent, for example, considering the solubility and dispersibility of the various additives contained in the dielectric slurry. The solvent can be mixed in an amount of 50 to 1000 parts by weight per 100 parts by weight of the barium titanate compound, for example, 100 to 500 parts by weight. When the solvent is mixed within the above content range, the dielectric slurry components can be thoroughly mixed, and subsequent removal of the solvent is also easy. 【0150】 The aforementioned dielectric slurry can be mixed using a wet ball mill or a stirring mill. When using zirconia balls in a wet ball mill, a large number of zirconia balls with diameters ranging from 0.1 mm to 10 mm can be used for wet mixing for 8 to 48 hours, or 10 to 24 hours. 【0151】 The manufactured dielectric slurry is formed as a dielectric layer after firing. 【0152】 Methods for forming the manufactured dielectric slurry into a sheet shape include tape molding methods such as the doctor blade method and the calender roll method, or, for example, using an on-roll molding coater with a head discharge system. A dielectric green sheet can then be obtained by drying the molded body. 【0153】 After firing, a conductive paste can be manufactured by mixing conductive powder made of a conductive metal or an alloy thereof, a binder, and a solvent to form a conductive paste layer that will become the internal electrode layer. Additionally, barium titanate powder may be mixed in as a co-material if necessary. The co-material can suppress the sintering of the conductive powder during the firing process. The conductive paste layer is then formed on the surface of the dielectric green sheet by applying the conductive paste in a predetermined pattern using various printing methods such as screen printing or transfer methods. 【0154】 The conductive powder may include nickel (Ni) or a nickel (Ni) alloy. 【0155】 Next, a dielectric green sheet laminate is manufactured by stacking multiple dielectric green sheets with internal electrode patterns formed on them in layers, and then pressing them in the stacking direction. At this time, the dielectric green sheets and internal electrode layer patterns can be stacked such that dielectric green sheets are located on the upper and lower surfaces of the dielectric green sheet laminate in the stacking direction. 【0156】 The step of cutting the manufactured dielectric green sheet laminate to predetermined dimensions by dicing or other means can be selectively performed. 【0157】 Furthermore, the dielectric green sheet laminate can be solidified and dried to remove plasticizers and other substances as needed, and after solidification and drying, it 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 along with media and polishing fluid, and unwanted parts such as burrs generated during cutting can be polished off by applying rotational motion or vibration to the barrel container. After barrel polishing, the dielectric green sheet laminate can be washed with a cleaning solution such as water and then dried. 【0158】 Next, the dielectric green sheet laminate can be debindered (calcined) and fired to manufacture a capacitor body. 【0159】 The debinding treatment conditions can be appropriately adjusted according to the components of the dielectric layer and the internal electrode layer. For example, the heating rate during debinding may be 5°C / hour to 300°C / hour, the support temperature 180°C to 400°C, and the temperature maintenance time 0.5 hours to 24 hours. The atmosphere during debinding may be air or a reducing atmosphere. 【0160】 The firing conditions can be appropriately adjusted according to the composition of the main components of the dielectric layer and the internal electrode layer. For example, firing can be carried out at a temperature of 1100°C to 1400°C, for example, 1200°C to 1350°C. Furthermore, firing can be carried out for 0.5 hours to 8 hours, for example, 1 hour to 3 hours. Also, firing can be carried out in a reducing atmosphere, for example, a humidified atmosphere of a mixed gas of nitrogen and hydrogen, for example, under conditions of a hydrogen concentration of 1.0% or less. If the internal electrode layer contains nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere should be 1.0 × 10⁻⁶. -14 MPa ~ 1.0 × 10 -10 MPa is also acceptable. 【0161】 After firing, annealing can be performed as needed. Annealing is a process to re-oxidize the dielectric layer, and can be performed when firing is carried out in a reducing atmosphere. The conditions for the annealing process can also be adjusted as appropriate according to the composition of the dielectric layer. For example, the temperature during annealing may be 950°C to 1150°C, the time may be 0 to 20 hours, and the heating rate may be 50°C / hour to 500°C / hour. The annealing atmosphere may be a humidified nitrogen gas (N2) atmosphere, and the oxygen partial pressure may be 1.0 × 10⁻⁶. -9 MPa ~ 1.0 × 10 -5 MPa is also acceptable. 【0162】 For humidifying nitrogen gas or mixed gases during debinding, calcination, or annealing, a wetter, for example, can be used, in which case the water temperature may be between 5°C and 75°C. Debinding, calcination, and annealing can be performed continuously or independently. 【0163】 Selectively, the third and fourth surfaces of the manufactured capacitor body 110 can be subjected to surface treatments such as sandblasting, laser irradiation, and barrel polishing. By performing such surface treatments, the edges of the first and second internal electrode layers can be exposed on the outermost surfaces of the third and fourth surfaces, thereby improving the electrical connection between the first and second external electrodes and the first and second internal electrode layers, and facilitating the formation of the alloy portion. 【0164】 Next, an external electrode is formed on one surface of the manufactured capacitor body 110. 【0165】 For example, a paste for forming a sintered metal layer can be applied to an external electrode and then sintered to form a sintered metal layer. 【0166】 The paste for forming a sintered metal layer may contain conductive metals and glass. The explanation of conductive metals and glass is the same as described above, so a repetition is omitted. The paste for forming a sintered metal layer may also selectively contain binders, solvents, dispersants, plasticizers, oxide powders, etc. Binders can be, for example, ethyl cellulose, acrylic, butyral, etc., and solvents can be organic solvents or aqueous solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, etc. 【0167】 Methods for applying the sintered metal layer-forming paste to the outer surface of the capacitor body 110 include the dip method, various printing methods such as screen printing, application methods using dispensers, and spraying methods using sprayers. The sintered metal layer-forming paste is applied to at least the third and fourth surfaces of the capacitor body 110, and can also be applied to parts of the first, second, fifth, or sixth surfaces where the band portions of the first and second external electrodes are selectively formed. 【0168】 Subsequently, the capacitor body 110 coated with the paste for forming a sintered metal layer is dried and then fired at a temperature of 700°C to 1000°C for 0.1 to 3 hours to form a sintered metal layer. 【0169】 Selectively, a conductive resin layer can be formed by applying a conductive resin layer-forming paste to the outer surface of the obtained capacitor body 110 and then curing it. 【0170】 The paste for forming a conductive resin layer may contain a resin and, selectively, a conductive metal or a non-conductive filler. The descriptions of conductive metals and resins are the same as above, so a repetition is omitted. The paste for forming a conductive resin layer may also selectively contain a binder, solvent, dispersant, plasticizer, oxide powder, etc. Binders can be, for example, ethyl cellulose, acrylic, or butyral, and solvents can be organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or aqueous solvents. 【0171】 For example, the conductive resin layer can be formed by dipping the capacitor body 110 into a conductive resin layer forming paste and then curing it, printing the conductive resin layer forming paste onto the surface of the capacitor body 110 using screen printing or gravure printing, or applying the conductive resin layer forming paste to the surface of the capacitor body 110 and then curing it. 【0172】 Next, a plating layer is formed on the outside of the conductive resin layer. 【0173】 For example, the plating layer can be formed by a plating method, and may be formed by sputtering or electroplating (electric deposition). 【0174】 The embodiments described above will be explained in more detail below through the examples provided. However, the following examples are for illustrative purposes only and do not limit the scope of rights. 【0175】 (Manufacturing of dielectric powder) Manufacturing Example 1 A slurry was prepared by dispersing BaTiO3 powder in an aqueous solution, to which tetraethyl orthosilicate (TEOS) was added. The slurry was then subjected to hydrothermal treatment at 200°C to create a primary coating of TEOS on the surface of the BaTiO3. At this time, TEOS was added in a concentration of 0.24 moles of Si per 100 moles of BaTiO3. Subsequently, SnO2 was added to the slurry containing the primary coated intermediate, and the slurry was subjected to hydrothermal treatment at 250°C to create a secondary coating of SnO2 on the surface of the primary coated TEOS, thereby producing a dielectric powder. At this time, SnO2 was added in the form of a sol dispersed in aqueous ammonia, and the concentration of SnO2 was 1 mole of Sn per 100 moles of BaTiO3. 【0176】 Manufacturing Example 2 The dielectric powder was manufactured in the same manner as in Manufacturing Example 1, except that TEOS was added in a quantity such that Si was 0.41 molar parts per 100 molar parts of BaTiO3. 【0177】 Manufacturing Example 3 The dielectric powder was manufactured in the same manner as in Manufacturing Example 1, except that SnO2 was added in an amount of 1.5 moles of Sn per 100 moles of BaTiO3. 【0178】 Manufacturing Example 4 The dielectric powder was manufactured in the same manner as in Manufacturing Example 1, except that SnO2 was added in an amount of 2 moles of Sn per 100 moles of BaTiO3. 【0179】 Comparative Manufacturing Example 1 Dielectric powder was produced by adding SnO2 to a slurry in which BaTiO3 powder was dispersed in an aqueous solution, and then hydrothermally treating it at 250°C to coat the surface of the BaTiO3 with SnO2. At this time, SnO2 was added in the form of a sol dispersed in ammonia water, and the amount of SnO2 added was 1 mole part of Sn per 100 mole parts of BaTiO3. 【0180】 (Manufacturing of multilayer ceramic capacitors) Example 1 A dielectric slurry was prepared by mixing the dielectric powder produced in Production Example 1 with a secondary component powder containing Dy2O3. The Dy2O3 was mixed in such a way that it was 1.3 moles of Dy relative to 100 moles of BaTiO3 used in the production of the dielectric powder. During the production of the dielectric slurry, mixing was performed by mechanical milling after adding zirconia balls (ZrO2Ball) as a dispersion medium, along with ethanol / toluene, a wetting dispersant, and polyvinyl butyral (PVB) resin as a binder. 【0181】 Dielectric green sheets were manufactured using a head-dispensing type on-roll molding coater with the manufactured dielectric slurry. 【0182】 A dielectric green sheet laminate was manufactured by printing a conductive paste layer containing nickel (Ni) onto the surface of a dielectric green sheet, and then laminating and pressing the dielectric green sheets with the conductive paste layer formed on them. 【0183】 The dielectric green sheet laminate was fired under conditions of firing at a temperature of 1300°C or lower and a hydrogen concentration of 1.0%H2 or lower, after a firing process at a temperature of 400°C or lower and in a nitrogen atmosphere. 【0184】 Next, multilayer ceramic capacitors were manufactured through processes such as external electrode assembly and plating. 【0185】 Example 2 A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that the dielectric powder manufactured in Example 2 was used instead of the dielectric powder manufactured in Example 1. 【0186】 Example 3 A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that the dielectric powder manufactured in Example 3 was used instead of the dielectric powder manufactured in Example 1. 【0187】 Example 4 A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that the dielectric powder manufactured in Example 4 was used instead of the dielectric powder manufactured in Example 1. 【0188】 Comparative Example 1 A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that a dielectric slurry was prepared by mixing BaTiO3 and auxiliary component powders containing SiO2 and Dy2O3. 【0189】 Evaluation 1: Confirmation of the structure and composition of dielectric powder To confirm the structure of the dielectric powder produced in Production Example 1, HR-TEM (high-resolution transmission electron microscopy) analysis and IFFTHR-TEM (inverse Fourier transform high-resolution transmission electron microscopy) analysis were performed, and the results are shown in Figures 7A and 7B. 【0190】 HR-TEM and IFFTHR-TEM analyses were performed on the dielectric powder under conditions of an acceleration voltage of 200kV and a magnification of 630k. 【0191】 Figure 7A shows an HR-TEM (high-resolution transmission electron microscope) analysis image of the dielectric powder according to Manufacturing Example 1, and Figure 7B shows an IFFTHR-TEM (inverse Fourier transform high-resolution transmission electron microscope) analysis image of the dielectric powder according to Manufacturing Example 1. 【0192】 Referring to Figures 7A and 7B, it can be seen that the dielectric powder produced by Production Example 1 has a structure comprising a core, a first layer disposed on at least a portion of the core, and a second layer disposed on at least a portion of the first layer. It can also be seen that the BaTiO3 core is present inside without damage, and layers with altered crystalline structures due to the metal oxide coating are distributed on the outside. 【0193】 Furthermore, TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) analysis was performed to confirm the structure and composition of the dielectric powder produced in Production Example 1, and the results are shown in Figures 8 and 9. 【0194】 TEM-EDS analysis was performed as follows: The dielectric powder was measured using a TEM (transmission electron microscope) under conditions of an acceleration voltage of 200 kV and a magnification of 630 kV. The structure and composition of the dielectric powder were confirmed by performing EDS (energy-dispersive spectroscopy) analysis on the obtained TEM images. In addition, EDS line analysis was performed on a straight section from the center of the dielectric powder to either boundary on the obtained TEM images to confirm the composition of the dielectric powder. 【0195】 Figure 8 shows an image of TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) analysis of the dielectric powder related to Manufacturing Example 1, and Figure 9 shows an image of TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) line analysis of the dielectric powder related to Manufacturing Example 1. 【0196】 Referring to Figure 8, in the case of the dielectric powder manufactured in Manufacturing Example 1, it can be confirmed that it has a structure including a core, a first layer disposed on at least a portion of the core, and a second layer disposed on at least a portion of the first layer, and that both Si and Sn are present in the first and second layers. Furthermore, it can be confirmed that the barrier layer of the first layer prevents the metal oxide from diffusing further into the dielectric powder, thus forming a barrier layer of the second layer. 【0197】 Furthermore, referring to the TEM-EDS line analysis results in Figure 9, the core, first layer, and second layer can be distinguished based on the point where Sn is 0.2 moles per 100 moles of Ti. That is, the first layer is the region where Sn is 0.2 moles or more per 100 moles of Ti, and the core and second layer are the regions where Sn is less than 0.2 moles per 100 moles of Ti. The core can be defined as the internal region toward the center of the dielectric powder relative to the first layer, and the second layer as the external region toward the outside relative to the first layer. 【0198】 Evaluation 2: TEM-EDS analysis of the dielectric layer TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) analysis was performed on the dielectric layers of the multilayer ceramic capacitors manufactured in Examples 1-4 and Comparative Example 1 using the method described below, and the results are shown in Figures 10 and 11. 【0199】 After curing each multilayer ceramic capacitor in an epoxy mixture, the W-axis and T-axis planes (WT planes) of the capacitor body were polished to a depth of 1 / 2 in the L-axis direction to obtain cross-sectional samples that allowed observation of the active region where the dielectric layer and internal electrode layer intersected. Subsequently, the active region of the cross-sectional sample was divided into three equal parts: the upper region, the middle region, and the lower region. Each region was then measured using a TEM (transmission electron microscope) to ensure that at least one dielectric layer and one internal electrode layer were visible. The TEM was performed using a Xe-FIB (focused ion beam) under conditions of an acceleration voltage of 200kV and a magnification of 450k. Subsequently, energy-dispersive spectroscopy (EDS) analysis of the dielectric layer was performed on the TEM images of the measured cross-sectional samples. 【0200】 Furthermore, TEM-EDS line analysis was performed on the TEM images of the measured cross-sectional samples, along the long axis passing through the center of the dielectric crystal grains having a core-shell structure. 【0201】 Figure 10 shows a TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) mapping analysis image of the dielectric layer according to Example 1, and Figure 11 shows a TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) line analysis image of the dielectric layer according to Example 1. 【0202】 Referring to Figure 10, it can be seen that the dielectric layer of Example 1 includes dielectric crystal grains having a core-shell structure, and crystal grain boundaries, with Si and Sn present in both the shell portion and the crystal grain boundaries. 【0203】 Furthermore, referring to the TEM-EDS line analysis results in Figure 11, when performing TEM-EDS line analysis along the long axis passing through the center of a dielectric crystal grain having a core-shell structure, the region where Dy is greater than approximately 0.3 moles relative to 100 moles of Ti can be defined as the grain boundary, the region where Dy is between approximately 0.15 moles and approximately 0.3 moles relative to 100 moles of Ti can be defined as the shell region, and the region where Dy is less than approximately 0.15 moles relative to 100 moles of Ti can be defined as the core region. 【0204】 Furthermore, the Sn / Si molar ratio (X) in the shell region and the molar ratio of Sn in the shell region to Sn at the grain boundaries (Y) were measured using the method described below, and the results are shown in Table 1. 【0205】 In the TEM images of the upper, central, and lower regions within the active area, a total of 10 dielectric grains with core-shell structures were selected (3, 4, and 3 in each region). EDS line analysis was performed on the linear intervals from the center of each selected dielectric grain to either grain boundary. 【0206】 Next, in Table 1 below, X was determined by measuring the Sn / Si molar ratio within the shell for each dielectric crystal grain and taking the average value for a total of 10 grains. In this case, the Sn / Si molar ratio within the shell for each dielectric crystal grain was determined by measuring the Sn / Si molar ratio at three equally spaced points within the shell of a single dielectric crystal grain and taking the average value. Furthermore, the Sn / Si molar ratio at each point is the molar ratio of Sn and Si content measured relative to 100 molar parts of Ti at that point. 【0207】 Furthermore, in Table 1 below, Y was determined by measuring the molar ratio of Sn in the shell to Sn at the grain boundaries for each dielectric crystal grain and taking the average value for a total of 10 measurements. At this time, the molar ratio of Sn in the shell to Sn at the grain boundaries for each dielectric crystal grain was determined by measuring the Sn content at three equally spaced points within the shell and three equally spaced points within the grain boundaries of a single dielectric crystal grain, and then taking the average value after measuring the molar ratio of Sn in the shell to Sn at the grain boundaries for any three arbitrary points. In addition, the Sn content at each point was measured relative to 100 molar parts of Ti at that point. 【0208】 [Table 1] 【0209】 Rating 3: Relative permittivity The relative permittivity was measured for the multilayer ceramic capacitors of Examples 1-4 and Comparative Example 1 under conditions of 1 kHz and 0.5 V, and the results are shown in Table 2 below. 【0210】 Rating 4: Temperature characteristics The capacitance change rate (temperature coefficient of capacitance, TCC) was measured for the multilayer ceramic capacitors of Examples 1-4 and Comparative Example 1, and the results are shown in Table 2 below. 【0211】 TCC was measured under conditions of 1 kHz, 0.01 V, and a duration of 5 minutes. 【0212】 Rating 5: Reliability The accelerated lifetime reliability (MTTF) was measured for the multilayer ceramic capacitors of Examples 1-4 and Comparative Example 1 using the method described below, and the results are shown in Table 2 and Figures 12 and 13. 【0213】 The mean time to failure (MTTF) was measured for each of 20 samples under the conditions of 125°C, 9.45V, and 48 hours. 【0214】 Figure 12 is a graph showing the reliability of the multilayer ceramic capacitor according to Example 1, and Figure 13 is a graph showing the reliability of the multilayer ceramic capacitor according to Comparative Example 1. 【0215】 Referring to Figures 12 and 13, it can be seen that Example 1 has superior reliability compared to Comparative Example 1. 【0216】 [Table 2] 【0217】 Referring to Table 2 above, it can be seen that in Examples 1 to 4, compared to Comparative Example 1, the relative permittivity is higher, the capacitance change at high temperatures is smaller, the temperature characteristics are excellent, and the reliability is superior. From this, it can be seen that a multilayer ceramic capacitor using the dielectric powder according to one embodiment, in which the dielectric layer has dielectric crystal grains and crystal grain boundaries having a core-shell structure, and in which Si and Sn are included in the shell portion and crystal grain boundaries, exhibits excellent temperature characteristics and reliability. 【0218】 Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to implement it in various ways within the scope of the claims, description of the invention, and attached drawings, and this is naturally also within the scope of the present invention. [Explanation of Symbols] 【0219】 10 Dielectric powder 11 cores 12 1st layer 13 2nd layer 20 Dielectric crystal grains 21 Core section 22 Shell section 30 grain boundary 100 Multilayer Ceramic Capacitors 110 Capacitor Body 111 Dielectric layer 112 Coverage Area 113 Coverage Area 121 1st internal electrode layer 122 Second internal electrode layer 131 1st external electrode 132 2nd external electrode

Claims

[Claim 1] A core containing barium (Ba) and titanium (Ti); A first layer disposed on at least a portion of the core; A second layer disposed on at least a portion of the first layer; At least one of the first layer and the second layer contains one or more first elements selected from silicon (Si) and aluminum (Al), The first and second layers are dielectric powders comprising one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). [Claim 2] The first and second layers contain tin (Sn), When performing TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) line analysis on a linear section from the center of the dielectric powder to either boundary, The first layer is a region in which the amount of tin (Sn) is 0.2 moles or more relative to 100 moles of titanium (Ti), The dielectric powder according to claim 1, wherein the core and the second layer are regions in which the tin (Sn) is less than 0.2 moles per 100 moles of titanium (Ti). [Claim 3] The dielectric powder according to claim 1, wherein the content of the second element is higher in the first layer than in the second layer. [Claim 4] The dielectric powder according to claim 1, wherein the first layer and the second layer each contain the first element. [Claim 5] The dielectric powder according to claim 1, wherein the first layer and the second layer contain the second element in oxide form. [Claim 6] At least one of the first layer and the second layer contains silicon (Si), The dielectric powder according to claim 1, wherein the first layer and the second layer contain tin (Sn). [Claim 7] The dielectric powder according to claim 1, wherein the first layer and the second layer comprise silicon (Si) and tin (Sn). [Claim 8] A capacitor body including a dielectric layer and an internal electrode layer, and Includes external electrodes positioned outside the capacitor body, The dielectric layer includes a plurality of dielectric crystal grains and grain boundaries arranged between the plurality of dielectric crystal grains. At least one of the plurality of dielectric crystal grains has a core-shell structure including a core portion and a shell portion disposed on at least a part of the core portion. A multilayer ceramic capacitor in which the shell portion and the grain boundaries contain one or more first elements selected from silicon (Si) and aluminum (Al), and one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). [Claim 9] The multilayer ceramic capacitor according to claim 8, wherein the molar ratio of the second element to the first element in the shell portion is greater than 0.15 and less than 1.

0. [Claim 10] The multilayer ceramic capacitor according to claim 8, wherein the molar ratio of the second element contained in the shell portion to the second element contained in the grain boundary is 2.0 or more and less than 6.

0. [Claim 11] The multilayer ceramic capacitor according to claim 8, wherein the core portion comprises barium (Ba) and titanium (Ti). [Claim 12] The multilayer ceramic capacitor according to claim 8, wherein the shell portion and the grain boundaries contain silicon (Si) and tin (Sn). [Claim 13] A multilayer ceramic capacitor utilizing the dielectric powder described in any one of claims 1 to 7, A capacitor body including a dielectric layer and an internal electrode layer, and Includes external electrodes positioned outside the capacitor body, The dielectric layer includes a plurality of dielectric crystal grains and grain boundaries arranged between the plurality of dielectric crystal grains. At least one of the plurality of dielectric crystal grains has a core-shell structure including a core portion and a shell portion disposed on at least a part of the core portion. A multilayer ceramic capacitor in which the shell portion and the grain boundaries contain one or more first elements selected from silicon (Si) and aluminum (Al), and one or more second elements selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). [Claim 14] The multilayer ceramic capacitor according to claim 13, wherein the molar ratio of the second element to the first element in the shell portion is greater than 0.15 and less than 1.

0. [Claim 15] The multilayer ceramic capacitor according to claim 13, wherein the molar ratio of the second element contained in the shell portion to the second element contained in the grain boundary is 2.0 or more and less than 6.

0. [Claim 16] The multilayer ceramic capacitor according to claim 13, wherein the core portion comprises barium (Ba) and titanium (Ti). [Claim 17] The multilayer ceramic capacitor according to claim 13, wherein the shell portion and the grain boundaries contain silicon (Si) and tin (Sn). [Claim 18] A method for producing dielectric powder according to any one of claims 1 to 7, The process involves adding a metal alkoxide compound to a solution containing a barium titanate compound and subjecting it to hydrothermal treatment to apply a primary coating of the metal alkoxide compound to the surface of the barium titanate compound; The step of adding a metal oxide after the primary coating and subjecting it to hydrothermal treatment to secondary coating the surface of the metal alkoxide compound with the metal oxide; The aforementioned metal alkoxide compound comprises one or more metals selected from silicon (Si) and aluminum (Al). A method for producing dielectric powder, wherein the metal oxide comprises one or more metals selected from tin (Sn), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn). [Claim 19] The method for producing dielectric powder according to claim 18, wherein the metal alkoxide compound comprises one or more selected from tetraethyl orthosilicate (TEOS), aluminum isopropoxide, and aluminum ethoxide. [Claim 20] The method for producing dielectric powder according to claim 18, wherein the metal alkoxide compound is added in an amount such that the metal of the metal alkoxide compound is 0.1 to 1 mole part per 100 mole parts of the barium titanate compound. [Claim 21] The aforementioned metal oxide is tin oxide (SnO ２ ), copper oxide (CuO), iron oxide (FeO, Fe ３ O ４ Fe ２ O ３ ), zinc oxide (ZnO) and manganese dioxide (MnO) ２ A method for producing dielectric powder according to claim 18, comprising one or more selected from the following. [Claim 22] The method for producing dielectric powder according to claim 18, wherein the metal oxide is added in an amount such that the metal of the metal oxide is 0.1 to 3 moles per 100 moles of the barium titanate-based compound. [Claim 23] The method for producing dielectric powder according to claim 18, wherein in the step of primary coating, the hydrothermal treatment is performed at a temperature of 100°C to 300°C. [Claim 24] The method for producing dielectric powder according to claim 18, wherein in the step of secondary coating, the hydrothermal treatment is performed at a temperature of 150°C to 350°C.

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