Multilayer ceramic capacitor and method of manufacturing the same

Abstract

To provide a multilayer ceramic capacitor having excellent high-temperature TCC (capacitance change rate) characteristics and reliability, and to provide a method of manufacturing the same.SOLUTION: According to an aspect of the present disclosure, a multilayer ceramic capacitor includes a capacitor body including a dielectric layer and an internal electrode layer, and an external electrode disposed on an outer surface of the capacitor body, wherein the dielectric layer includes a plurality of dielectric grains, a grainboundary disposed between the plurality of dielectric grains, and a triple point at which three grain boundaries are disposed in contact with each other, and the dielectric layer includes a secondary phase disposed at the triple point and including Dy, Al, and Si.SELECTED DRAWING: Figure 6b

Description

[Technical Field]

[0001] The present disclosure relates to a multilayer ceramic capacitor and a method for manufacturing the same. [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) are small in size, have high capacitance, and are easy to mount, making them suitable for use 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, and serve to charge or discharge electricity.

[0004] Recently, as multilayer ceramic capacitors are used in various fields such as IT and electrical equipment, they are being required to have more severe temperature characteristics. Summary of the Invention [Problem to be solved by the invention]

[0005] One embodiment provides a multilayer ceramic capacitor with excellent high temperature TCC (rate of capacitance change) characteristics and reliability.

[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 the outside of the capacitor body, the dielectric layer including a plurality of dielectric grains, grain boundaries disposed between the plurality of dielectric grains, and triple junctions where three grain boundaries are in contact with each other, and the dielectric layer including a secondary phase including Dy, Al, and Si disposed at the triple junctions.

[0008] The secondary phase may contain Dy in an amount of 15 atomic % or more and 25 atomic % or less relative to the total amount of the secondary phase.

[0009] The secondary phase may contain Al in an amount of 5 atomic % or more and 6 atomic % or less relative to the total amount of the secondary phase.

[0010] The secondary phase may contain Si in an amount of 70 atomic % or more and 80 atomic % or less relative to the total amount of the secondary phase.

[0011] The dielectric layer may include a barium titanate-based main component and a secondary component including Dy, Al, and Si.

[0012] The secondary components may further include one or more elements selected from the group consisting of Tb, V, Mn, and Mg.

[0013] The secondary phase Dy may be contained in the dielectric layer in an amount of 0.95 atomic parts or more and 1.15 atomic parts or less with respect to the 100 atomic parts of Ti contained in the barium titanate-based main component.

[0014] The secondary phase Al may be contained in the dielectric layer in an amount of 0.30 atomic parts or more and 0.34 atomic parts or less relative to 100 atomic parts of Ti contained in the barium titanate-based main component.

[0015] The secondary phase Si may be contained in the dielectric layer in an amount of 4.0 atomic parts or more and 4.4 atomic parts or less relative to 100 atomic parts of Ti contained in the barium titanate-based main component.

[0016] The area occupied by the secondary phase may be 0.15% or more and 1% or less of the total area of ​​the dielectric layer.

[0017] Another embodiment provides a method for manufacturing a multilayer ceramic capacitor, the method comprising the steps of: preparing a dielectric slurry by mixing a barium titanate-based main component powder with auxiliary component powders including a Dy-containing compound, an Al-containing compound, and a Si-containing compound; preparing a dielectric green sheet using the dielectric slurry and forming a conductive paste layer on a surface of the dielectric green sheet; laminating the dielectric green sheets on which the conductive paste layer is formed 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, wherein the dielectric layer includes a plurality of dielectric grains, grain boundaries disposed between the plurality of dielectric grains, and triple junctions where three grain boundaries are adjacent to each other, and the dielectric layer includes a secondary phase including Dy, Al, and Si disposed at the triple junctions.

[0018] The Dy-containing compound may be mixed in an amount of 0.5 to 1.2 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

[0019] The Al-containing compound may be mixed in an amount of 0.1 to 0.5 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

[0020] The Si-containing compound may be mixed in an amount of 1 part by mol or more and 5 parts by mol or less with respect to 100 parts by mol of the barium titanate-based main component powder.

[0021] The auxiliary component powder may further include at least one selected from the group consisting of a Tb-containing compound, a V-containing compound, a Mn-containing compound, and a Mg-containing compound.

[0022] The baking can be carried out for a maintenance time of 10 seconds to 3 minutes.

[0023] The firing can be carried out at a temperature of 1160°C or higher and 1250°C or lower. [Effects of the Invention]

[0024] In the multilayer ceramic capacitor according to an embodiment, the solid dissolution of additives in the barium titanate-based dielectric is suppressed, thereby improving high-temperature TCC (rate of capacitance change) characteristics while maintaining high reliability. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view illustrating a multilayer ceramic capacitor according to an embodiment; [Figure 2] FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. [Figure 3] 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. [Figure 4] 2 is an exploded perspective view showing the laminated structure of the internal electrode layers in the capacitor body of FIG. 1. FIG. [Figure 5] FIG. 2 is a schematic diagram illustrating a cross section of a dielectric layer according to one embodiment. [Figure 6a] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Example 1. [Figure 6b] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Example 1. [Figure 6c] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Example 1. [Figure 6d] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Example 1. [Figure 7a]1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Comparative Example 1. [Figure 7b] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Comparative Example 1. [Figure 7c] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Comparative Example 1. [Figure 7d] 1 is a TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis image of a dielectric layer according to Comparative Example 1. [Figure 8] 1 is a graph showing the temperature coefficient of capacitance (TCC) of multilayer ceramic capacitors according to Example 1, Comparative Example 1, and Comparative Example 2. [Figure 9] 4 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Example 1. [Figure 10] 10 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Comparative Example 1. [Figure 11] 10 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Comparative Example 2. [Figure 12] 4 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Example 1. [Figure 13] 10 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Comparative Example 1. [Figure 14] 10 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, 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 order to clearly explain the present invention in the drawings, parts unnecessary for explanation are omitted, and the same reference numerals are used throughout the specification to refer to the same or similar components. Furthermore, in the accompanying drawings, some components are exaggerated, omitted, or illustrated schematically, and the size of each component does not entirely reflect the actual size.

[0027] The attached drawings are merely for the purpose of facilitating understanding of the embodiments disclosed in this specification, and it should be understood that the attached drawings do not limit the technical ideas disclosed in this specification, and include all modifications, equivalents, and alternatives included in the idea and technical scope of the present invention.

[0028] Terms including ordinal numbers such as "first," "second," etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

[0029] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly on" another 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. Furthermore, 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.

[0030] Throughout the specification, the use of terms such as "comprises" or "having" is intended to specify the presence of a stated feature, number, step, operation, component, part, or combination thereof, but should be understood not to preclude the presence or addition of one or more other features, numbers, 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.

[0031] Also, throughout the specification, "on a plane" means when the subject part is viewed from above, and "on a cross section" means when the subject part is cut vertically and viewed from the side.

[0032] Furthermore, throughout the specification, when the term "connected" is used, it 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, that two or more components are not only physically connected but also electrically connected, or that two or more components are referred to by different names depending on their position or function but are nonetheless one unit.

[0033] Hereinafter, a multilayer ceramic capacitor according to an embodiment will be described with reference to FIGS.

[0034] FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to an embodiment, FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. 1, FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. 1, and FIG. 4 is an exploded perspective view showing the stacked structure of internal electrode layers in the capacitor body of FIG. 1.

[0035] The L axis, W axis, and T axis shown in FIGS. 1 to 4 indicate the length direction, width direction, and thickness direction, respectively, 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 may be used as the same concept as the stacking direction of the dielectric layers 111. The length direction (L axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet-shaped component and substantially perpendicular to the thickness direction (T axis direction). For example, it may be a direction in which the first external electrode 131 and the second external electrode 132 are located on both sides. The width direction (W axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet-shaped component and substantially perpendicular to the thickness direction (T axis direction) and the length direction (L axis direction). The length of the length direction (L axis direction) of the sheet-shaped component may be longer than the length of the width direction (W axis direction).

[0036] 1 to 4, a multilayer ceramic capacitor 100 according to an embodiment includes a capacitor body 110 and external electrodes 131 and 132 disposed on the outside 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).

[0037] The capacitor body 110 may be, for example, generally hexahedral in shape.

[0038] For the sake of convenience in 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 that are connected to the first surface and the second surface and face each other in the length direction (L-axis direction) are defined as the third surface and the fourth surface, and the two surfaces that are connected to the first surface and the second surface and the third surface and the fourth surface and face each other in the width direction (W-axis direction) are defined as the fifth surface and the sixth surface.

[0039] As an example, the first surface, which is the bottom surface, may be the surface facing the mounting direction. Furthermore, the first to sixth surfaces may be flat, but this is not a limitation of the embodiment. For example, the first to sixth surfaces may be curved surfaces with convex central portions, and the corners at the boundaries between the surfaces may be rounded.

[0040] 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.

[0041] 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.

[0042] At this time, the boundaries between the adjacent dielectric layers 111 of the capacitor body 110 may be integrated to such an extent that they are difficult to identify without using a scanning electron microscope (SEM).

[0043] The capacitor body 110 may include an active area and a cover area 112 , 113 .

[0044] 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 electrode layer 121 or the second internal electrode layer 122 stacked along the thickness direction (T-axis direction) overlaps.

[0045] The cover regions 112 and 113 are thickness direction margins and can be arranged on the first and second surfaces of the active region in the thickness direction (T axis direction), respectively. These cover regions 112 and 113 can be a single dielectric layer 111 or two or more dielectric layers 111 stacked on the upper and lower surfaces of the active region, respectively.

[0046] Additionally, the capacitor body 110 may further include a side margin region.

[0047] The side margin regions are widthwise margins and may be disposed on both opposing ends of the active region in the widthwise direction (W-axis direction), i.e., on the fifth and sixth surfaces, respectively. The side margin regions may be formed by, when 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 portion 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 surface of the dielectric green sheet, and then firing the laminate; however, the method of formation is not limited to this.

[0048] The cover regions 112 and 113 and the side margin regions serve to prevent damage to the first internal electrode layer 121 and the second internal electrode layer 122 due to physical or chemical stress.

[0049] The dielectric layers, internal electrode layers, and external electrodes will be described in detail below.

[0050] [Dielectric layer] The dielectric layer will be described with reference to FIG.

[0051] FIG. 5 is a schematic diagram illustrating a cross section of a dielectric layer according to one embodiment.

[0052] 5, the dielectric layer 111 may include a plurality of dielectric grains 10, grain boundaries 20 disposed between a plurality of adjacent dielectric grains 10, and triple junctions 30 where three grain boundaries 20 meet. The triple junction 30 refers to a point where three grain boundaries 20 meet, and at least one triple junction 30 may be included in the dielectric layer.

[0053] According to an embodiment, the dielectric layer 111 may include a secondary phase disposed at the triple point 30. In this case, the secondary phase may include elements of dysprosium (Dy), aluminum (Al), and silicon (Si).

[0054] The secondary phase may refer to a new phase precipitated after firing a dielectric green sheet laminate. In other words, when firing a dielectric green sheet laminate obtained using a dielectric slurry prepared by mixing a barium titanate-based main component and a minor component corresponding to an additive, the additive, such as a rare earth element, may not be dissolved in the barium titanate lattice but may be precipitated in the form of a secondary phase.

[0055] Furthermore, Dy, Al, and Si contained in the secondary phase may be chemically bonded to each other and exist in the form of a compound.

[0056] When a plurality of triple junctions 30 exist in the dielectric layer, the secondary phase may be included in at least one of the plurality of triple junctions 30 .

[0057] As the amount of additives, such as rare earth elements such as Dy, added together with the barium titanate-based main component to form the dielectric layer increases, the deterioration of temperature characteristics such as the temperature coefficient of capacitance (TCC) accelerates. However, since the amount of additives also improves reliability, it is difficult to simply reduce the amount of additives. According to one embodiment, temperature characteristics such as the TCC characteristic can be improved while maintaining reliability characteristics by varying the degree of solid solubility in the barium titanate-based main component without reducing the amount of additives. That is, according to one embodiment, when a secondary phase containing Dy, Al, and Si is located at the triple point 30 in the dielectric layer 111, the solid solubility of the additive in the barium titanate dielectric is suppressed, thereby improving high-temperature TCC characteristics while maintaining high reliability.

[0058] The presence of a secondary phase containing Dy, Al, and Si at the triple point 30 in the dielectric layer 111 can be confirmed through TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) analysis.

[0059] Specifically, the multilayer ceramic capacitor 100 is immersed in an epoxy mixture and cured. The W-axis and T-axis surfaces (WT surfaces) of the capacitor body 110 are then polished to a depth of 1 / 2 in the L-axis direction, fixed, and maintained in a vacuum atmosphere chamber 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. The active region of the cross-sectional sample can then be measured using a transmission electron microscope (TEM) to reveal at least one layer, for example, one to five layers, of the dielectric layer 111. For example, the TEM can be performed using a focused ion beam (Xe-FIB) at an acceleration voltage of 200 kV in an area of ​​approximately 400 nm × 400 nm where at least one layer of the dielectric layer 111 is visible in the active region. Next, EDS (energy dispersive spectroscopy) analysis is performed on the TEM image of the measured cross-sectional sample, and it can be confirmed that a secondary phase containing Dy, Al, and Si exists at the triple junction, which is the point where any three grain boundaries meet within the dielectric layer 111.

[0060] The dysprosium (Dy) content in the secondary phase may be 15 atomic % to 25 atomic % of the total amount of the secondary phase, for example, 17 atomic % to 23 atomic %, 18 atomic % to 22 atomic %, or 19 atomic % to 21 atomic %. When the Dy content in the secondary phase is within this range, solid dissolution of the additive into the barium titanate dielectric is suppressed, thereby improving high-temperature TCC characteristics while maintaining excellent reliability characteristics.

[0061] The aluminum (Al) content in the secondary phase may be 5 to 6 atomic percent of the total amount of the secondary phase, for example, 5.1 to 5.9 atomic percent, 5.2 to 5.8 atomic percent, or 5.3 to 5.7 atomic percent. When the Al content in the secondary phase is within this range, the additive is prevented from dissolving in the barium titanate dielectric, thereby improving high-temperature TCC characteristics while maintaining excellent reliability.

[0062] The silicon (Si) content in the secondary phase may be 70 atomic % to 80 atomic % of the total amount of the secondary phase, for example, 72 atomic % to 78 atomic %, 73 atomic % to 77 atomic %, or 74 atomic % to 76 atomic %. When the Si content in the secondary phase is within this range, the additive is prevented from dissolving in the barium titanate dielectric, thereby improving high-temperature TCC characteristics while maintaining excellent reliability characteristics.

[0063] The dielectric layer 111 may contain a barium titanate-based main component and a sub-component.

[0064] The barium titanate-based main component is a dielectric base material, which has a high dielectric constant and contributes to forming the dielectric constant of the multilayer ceramic capacitor 100 .

[0065] The barium titanate-based main component is a compound containing barium (Ba) and titanium (Ti), and may include, 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, (Ba,Sr)(Ti,Sn)O3, or combinations thereof.

[0066] The minor components can include Dy, Al, and Si. The minor components are distinct from the secondary phases present at the triple points 30 and can be present in at least one of the grains 10 and the grain boundaries 20 in the dielectric layer 111.

[0067] The secondary components may further include one or more elements selected from terbium (Tb), vanadium (V), manganese (Mn), and magnesium (Mg).

[0068] The Dy contained in the secondary phase may be present in an amount of 0.95 to 1.15 atomic parts, for example, 0.98 to 1.12 atomic parts, or 1.0 to 1.10 atomic parts, relative to the 100 atomic parts of Ti, the barium titanate-based main component, in the dielectric layer 111. When the Dy content of the secondary phase in the entire dielectric layer is within this range, solid dissolution of the additive into the barium titanate dielectric is suppressed, thereby improving high-temperature TCC characteristics while maintaining excellent reliability characteristics.

[0069] The Al contained in the secondary phase may be present in an amount of 0.30 atomic parts to 0.34 atomic parts, for example, 0.31 atomic parts to 0.33 atomic parts, relative to the Ti100 atomic parts of the barium titanate-based main component in the dielectric layer 111. When the Al content of the secondary phase in the entire dielectric layer is within this range, solid dissolution of the additive into the barium titanate dielectric is suppressed, thereby improving high-temperature TCC characteristics while maintaining excellent reliability characteristics.

[0070] The Si content in the secondary phase may be 4.0 atomic parts or more and 4.4 atomic parts or less, for example, 4.1 atomic parts or more and 4.3 atomic parts or less, relative to the Ti100 atomic parts of the barium titanate-based main component in the dielectric layer 111. When the Si content in the secondary phase in the entire dielectric layer is within this range, solid dissolution of the additive into the barium titanate dielectric is suppressed, thereby improving high-temperature TCC characteristics while maintaining excellent reliability characteristics.

[0071] The area occupied by the secondary phase in the dielectric layer 111 may be 0.15% to 1% of the total area of ​​the dielectric layer, for example, 0.18% to 0.9%, 0.2% to 0.8%, or 0.25% to 0.7%. The total area of ​​the dielectric layer may have a range of, for example, 400 nm±200 nm×400 nm±200 nm.

[0072] The contents of Dy, Al, and Si in the secondary phase and the dielectric layer, and the area of ​​the secondary phase can be confirmed through the above-mentioned TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis.

[0073] The average thickness (average length in the T-axis direction) of the dielectric layers 111 may be 0.1 μm or more and 8.0 μm or less, for example, 0.1 μm or more and 6.0 μm or less. When the average thickness of the dielectric layers 111 is within this range, the reliability of the multilayer ceramic capacitor is excellent.

[0074] The average thickness of the dielectric layer 111 can be measured by immersing the multilayer ceramic capacitor 100 in an epoxy mixture, curing it, polishing it, and then ion milling it, followed by scanning electron microscope (SEM) analysis. The scanning electron microscope may be, for example, a Verios G4 product from Thermofisher Scientific, with measurement conditions of 10 kV, 0.2 nA, and an analysis magnification of 100x. Measurements may be performed to show at least one, three, five, or ten dielectric layers 111. The center of the dielectric layer 111 in the length direction (L-axis direction) or width direction (W-axis direction) in the SEM image may be used as a reference point, and the arithmetic average of the thicknesses of the dielectric layer 111 at 10 points spaced at predetermined intervals from the reference point may be used. The interval between the 10 points can be adjusted according to the scale of the 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 10 points must be located within the dielectric layer 111. If all 10 points are not located within the dielectric layer 111, the positions of the reference points can be changed or the interval between the 10 points can be adjusted.

[0075] [Internal electrode layer] The internal electrode layers 121, 122, i.e., the first internal electrode layer 121 and the second internal electrode layer 122, are electrodes having different polarities and are alternately arranged facing each other along the T-axis direction with the dielectric layer 111 sandwiched therebetween, and one end is exposed through the third and fourth surfaces of the capacitor body 110, respectively.

[0076] 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 disposed therebetween.

[0077] 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.

[0078] The first internal electrode layer 121 and the second internal electrode layer 122 include a conductive metal, such as Ni, Cu, Ag, Pd, Au, or an alloy thereof, such as an Ag—Pd alloy.

[0079] Furthermore, the first internal electrode layers 121 and the second internal electrode layers 122 may contain dielectric particles of the same composition as the ceramic material contained in the dielectric layers 111 .

[0080] The first internal electrode layer 121 and the second internal electrode layer 122 can be formed using a conductive paste containing a conductive metal. The conductive paste can be printed by screen printing or gravure printing.

[0081] The average thickness of the first internal electrode layer 121 and the second internal electrode layer 122 may be 0.1 μm or more and 2 μm or less. The average thickness of the first internal electrode layer 121 and the second internal electrode layer 122 can be measured by scanning electron microscope (SEM) analysis. Here, the scanning electron microscope (SEM) analysis is the same as the method used to measure the average thickness of the dielectric layer 111 described above, so a description thereof will be omitted.

[0082] 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 stacked.

[0083] [External electrode] The external electrodes 131 and 132, i.e., the first external electrode 131 and the second external electrode 132, are supplied with voltages of different polarities and can be electrically connected to the exposed portions of the first internal electrode layer 121 and the second internal electrode layer 122, respectively.

[0084] With the above configuration, when a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charges are accumulated between the opposing first internal electrode layer 121 and second internal electrode layer 122. 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 that overlap each other along the T-axis direction in the active region.

[0085] 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 layer 121 and the second internal electrode layer 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.

[0086] The first and second band portions extend from the first and second connection portions to parts of the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. The first and second band portions may serve to improve the bonding strength between the first and second external electrodes 131 and 132.

[0087] 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.

[0088] The sintered metal layer may include a conductive metal and glass.

[0089] 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 a copper (Cu) alloy. 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.

[0090] The glass may include a mixed oxide composition, such as one or more oxides 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 oxides selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0091] 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.

[0092] 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 disposed extending 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 disposed extending to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. That is, the conductive resin layer may be formed on the sintered metal layer to completely cover the sintered metal layer.

[0093] The conductive resin layer includes a resin and a conductive metal.

[0094] The resin contained in the conductive resin layer is not particularly limited as long as it has bonding and impact absorption 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.

[0095] The conductive metal contained in the conductive resin layer serves to electrically connect the first internal electrode layer 121 and the second internal electrode layer 122 or the sintered metal layer.

[0096] 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 in a flake shape only, a spherical shape only, or a mixture of a flake shape and a spherical shape.

[0097] Here, the spherical shape may include shapes that are not perfectly spherical, for example, shapes 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, but may, for example, have a ratio of the major axis to the minor axis (major axis / minor axis) of 1.95 or more.

[0098] 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.

[0099] 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), either singly 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 nickel (Ni) plating layer and a tin (Sn) plating layer stacked in sequence, or a tin (Sn) plating layer, a nickel (Ni) plating layer, and a tin (Sn) plating layer stacked in sequence. The plating layer may also include multiple nickel (Ni) plating layers and / or multiple tin (Sn) plating layers.

[0100] The plating layer can improve the mountability of the multilayer capacitor 100 to a substrate, structural reliability, durability against external influences, heat resistance, and equivalent series resistance (ESR).

[0101] [Manufacturing method of multilayer ceramic capacitor] A method for manufacturing the multilayer ceramic capacitor 100 according to an embodiment will now be described.

[0102] The multilayer ceramic capacitor 100 according to one embodiment may be manufactured through the steps of: preparing a dielectric slurry by mixing a barium titanate-based main component powder with a sub-component powder including a Dy-containing compound, an Al-containing compound, and a Si-containing compound; preparing a dielectric green sheet using the dielectric slurry and forming a conductive paste layer on a surface of the dielectric green sheet; laminating the dielectric green sheets on which the conductive paste layer is formed 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.

[0103] The barium titanate-based main component powder is a compound containing barium (Ba) and titanium (Ti), and may include, 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, (Ba,Sr)(Ti,Sn)O3, or combinations thereof.

[0104] The Dy-containing compound, Al-containing compound, and Si-containing compound may each be an oxide, nitride, or salt compound, or may be used in the form of a sol dispersed in an organic solvent.

[0105] The Dy-containing compound may be mixed in an amount of 0.5 to 1.2 molar parts, for example, 0.6 to 1.1 molar parts, or 0.7 to 1.0 molar parts, per 100 molar parts of the barium titanate-based main component powder. When the Dy-containing compound is mixed in this amount range, secondary phase formation is induced, suppressing the dissolution of the additive into the barium titanate dielectric, thereby improving high-temperature TCC characteristics while maintaining high reliability.

[0106] The Al-containing compound may be mixed in an amount of 0.1 to 0.5 molar parts, for example, 0.2 to 0.4 molar parts, per 100 molar parts of the barium titanate-based main component powder. When the Al-containing compound is mixed in this amount range, secondary phase formation is induced, suppressing the dissolution of the additive into the barium titanate dielectric, thereby improving high-temperature TCC characteristics while maintaining high reliability.

[0107] The Si-containing compound may be mixed in an amount of 1 to 5 molar parts, for example, 1.5 to 4.5 molar parts, or 2 to 4 molar parts, per 100 molar parts of the barium titanate-based main component powder. When the Si-containing compound is mixed in this amount range, secondary phase formation is induced, suppressing the dissolution of the additive into the barium titanate dielectric, thereby improving high-temperature TCC characteristics while maintaining high reliability.

[0108] The auxiliary component powder may further include one or more selected from the group consisting of a Tb-containing compound, a V-containing compound, a Mn-containing compound, and a Mg-containing compound.

[0109] The dielectric slurry can be prepared by additionally mixing additives such as dispersants, binders, plasticizers, lubricants, antistatic agents, and solvents.

[0110] The dispersant may include, for example, a phosphate ester-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, per 100 parts by weight of the barium titanate-based compound. When the dispersant is mixed within this content range, the dispersibility of the dielectric slurry is excellent, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0111] The binder may be, for example, an acrylic resin, a polyvinyl butyral 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, per 100 parts by weight of the barium titanate-based compound. When the binder is mixed within this content range, the dispersibility of the dielectric slurry is excellent, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0112] Examples of plasticizers include phthalic acid 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 adipate and di(2-ethylhexyl) adipate; glycol compounds such as ethylene glycol, diethylene glycol, and triethylene glycol; and glycol ester compounds such as triethylene glycol dibutyrate, triethylene glycol di(2-ethylbutyrate), and 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, per 100 parts by weight of the barium titanate compound. When the plasticizer is mixed within the above content range, the dielectric slurry has excellent dispersibility and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0113] The solvent may be an aqueous solvent such as water; an alcoholic solvent such as ethanol, methanol, benzyl alcohol, or 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 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. The solvent may be an alcoholic solvent or an aromatic solvent, taking into consideration the solubility and dispersibility of the various additives contained in the dielectric slurry. The solvent may be mixed in an amount of 50 to 1,000 parts by weight, for example, 100 to 500 parts by weight, per 100 parts by weight of the barium titanate compound. When the solvent is mixed within the above content range, the dielectric slurry components can be thoroughly mixed and subsequent solvent removal is easy.

[0114] The dielectric slurry can be mixed using a wet ball mill or an agitator mill. When using zirconia balls in a wet ball mill, the mixture can be wet mixed for 8 to 48 hours, or 10 to 24 hours, using a large number of zirconia balls with a diameter of 0.1 mm to 10 mm.

[0115] The produced dielectric slurry is formed into a dielectric layer after firing.

[0116] The produced dielectric slurry can be formed into a sheet shape using a tape forming method such as a doctor blade method or a calendar roll method, for example, a head-discharging on-roll forming coater, and then the formed product can be dried to obtain a dielectric green sheet.

[0117] To form a conductive paste layer that will become an internal electrode layer after firing, a conductive paste can be prepared 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 sintering of the conductive powder during firing. The conductive paste layer is formed by applying the conductive paste in a predetermined pattern to the surface of a dielectric green sheet using various printing methods such as screen printing or transfer printing.

[0118] The conductive powder may include nickel (Ni) or a nickel (Ni) alloy.

[0119] Next, a plurality of dielectric green sheets on which the internal electrode patterns are formed are laminated and pressed in the lamination direction to manufacture a dielectric green sheet laminate. At this time, the dielectric green sheets and the internal electrode layer patterns can be laminated so that the dielectric green sheets are positioned on the upper and lower surfaces of the dielectric green sheet laminate in the lamination direction.

[0120] The manufactured dielectric green sheet laminate may optionally be cut into a predetermined size by dicing or the like.

[0121] 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 a polishing solution, and the barrel container is subjected to rotational motion, vibration, etc., to polish away unnecessary parts such as burrs generated during cutting. After barrel polishing, the dielectric green sheet laminate is washed with a cleaning liquid such as water and dried.

[0122] The dielectric green sheet laminate can then be debindered (plasticized) and fired to produce a capacitor body.

[0123] The binder removal treatment conditions can be appropriately adjusted depending on the components of the dielectric layer and the internal electrode layer. For example, the temperature rise rate during 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. The binder removal treatment may be performed in air or a reducing atmosphere.

[0124] 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 electrode layer. For example, firing can be performed at a temperature of 1160°C to 1250°C, such as 1180°C to 1240°C, 1190°C to 1230°C, or 1200°C to 1220°C. Furthermore, firing can be performed for a maintenance time of 10 seconds to 3 minutes, such as 20 seconds to 2.5 minutes, 30 seconds to 2 minutes, or 40 seconds to 1.5 minutes. Furthermore, firing can be performed in a reducing atmosphere, such as an atmosphere containing a humidified mixed gas of nitrogen and hydrogen, under conditions of, for example, a hydrogen concentration of 1.0% or less. When the internal electrode layer contains nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere can be 1.0 x 10 -14 MPa or more 1.0 x 10 -10 MPa or less.

[0125] After the firing treatment, annealing can be performed if necessary. Annealing is a treatment for reoxidizing the dielectric layer, and can be performed when firing treatment is performed in a reducing atmosphere. The conditions for the annealing treatment can also be appropriately adjusted depending on the components of the dielectric layer. For example, the annealing temperature can be 950°C or higher and 1150°C or lower, the annealing time can be 0 hours or higher and 20 hours or lower, and the temperature rise rate can be 50°C / hour or higher and 500°C / hour or lower. The annealing atmosphere can be a humidified nitrogen gas (N2) atmosphere, and the oxygen partial pressure can be 1.0 x 10 -9 MPa or more 1.0 x 10 -5 MPa or less.

[0126] In the binder removal treatment, firing treatment, or annealing treatment, a wetter or the like can be used to humidify nitrogen gas or mixed gas, and in this case, the water temperature can be 5° C. or higher and 75° C. or lower. The binder removal treatment, firing treatment, and annealing treatment can be performed consecutively or independently.

[0127] Optionally, the third and fourth surfaces 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 electrode layers are exposed on the outermost surfaces of the third and fourth surfaces, which improves electrical connection between the first and second external electrodes and the first and second internal electrode layers, making it easier to form alloy parts.

[0128] Next, an external electrode is formed on one surface of the manufactured capacitor body 110 .

[0129] For example, a sintered metal layer can be formed as an external electrode by applying a paste for forming a sintered metal layer and then sintering the paste.

[0130] The paste for forming the sintered metal layer may contain a conductive metal and glass. The description of the conductive metal and glass is the same as that described above, so repeated description will be omitted. The paste for forming the sintered metal layer may optionally contain a binder, a solvent, a dispersant, a plasticizer, an oxide powder, etc. Examples of binders that can be used include ethyl cellulose, acrylic, butyral, etc., and examples of solvents that can be used include organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, etc., or aqueous solvents.

[0131] The paste for forming a sintered metal layer can be applied to the outer surface of the capacitor body 110 by various printing methods such as dipping, screen printing, etc., application using a dispenser, spraying 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 parts of the first, second, fifth, or sixth surfaces on which the band portions of the first and second external electrodes are formed.

[0132] Thereafter, the capacitor body 110 coated with the paste for forming a sintered metal layer 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.

[0133] Alternatively, a conductive resin layer can be formed by applying a paste for forming a conductive resin layer to the outer surface of the obtained capacitor body 110 and then curing the paste.

[0134] 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 resin are the same as those described above, so repeated description will be omitted. The paste for forming the conductive resin layer may also include, optionally, a binder, a solvent, a dispersant, a plasticizer, an oxide powder, etc. Examples of binders that can be used include ethyl cellulose, acrylic, butyral, etc., and solvents that can be used include organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, etc., or aqueous solvents.

[0135] For example, the conductive resin layer may be formed by dipping the capacitor body 110 in 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.

[0136] Next, a plating layer is formed on the outside of the conductive resin layer.

[0137] For example, the plating layer can be formed by a plating method, such as sputtering or electric deposition.

[0138] The above-described embodiments will be described in more detail with reference to the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the invention. [Example]

[0139] (multilayer ceramic capacitor manufacturing) [Example 1] A dielectric slurry was produced by mixing barium titanate (BaTiO3) main component powder with dysprosium oxide (Dy2O3), aluminum oxide (Al2O3), and silicon dioxide (SiO2) as secondary component powders in amounts of 1 molar part, 0.3 molar parts, and 3 molar parts, respectively, per 100 molar parts of barium titanate (BaTiO3).

[0140] When preparing the dielectric slurry, zirconia balls (ZrO2 balls) were used as a dispersion medium, and ethanol / toluene, a wetting dispersant, and polyvinyl butyral (PVB) resin as a binder were added together, followed by mechanical milling.

[0141] The prepared dielectric slurry was used in a head-discharging on-roll forming coater to prepare a dielectric green sheet.

[0142] A conductive paste layer containing nickel (Ni) was printed on the surface of the dielectric green sheet, and the dielectric green sheets on which the conductive paste layer was formed were stacked and pressed together to manufacture a dielectric green sheet laminate.

[0143] The dielectric green sheet laminate was subjected to a plasticization process at 400°C or less in a nitrogen atmosphere, and then fired at a firing temperature of 1210°C for a maintenance time of 51 seconds under conditions of a hydrogen concentration of 0.11%.

[0144] Next, a multilayer ceramic capacitor was manufactured through processes such as external electrodes and plating.

[0145] [Comparative Example 1] A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that the firing was performed at a firing temperature of 1140° C. for 5 minutes with a hydrogen concentration of 0.11%.

[0146] Comparative Example 2 A multilayer ceramic capacitor was manufactured in the same manner as in Example 1, except that the firing was performed at a firing temperature of 1140° C. for 4 minutes with a hydrogen concentration of 0.11%.

[0147] [Evaluation 1: TEM-EDS analysis] The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were subjected to TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis, and the results are shown in FIGS. 6a to 6d and 7a to 7d.

[0148] Specifically, the multilayer ceramic capacitors fabricated in Example 1 and Comparative Example 1 were immersed in an epoxy mixture and cured. The W-axis and T-axis (WT) planes of the capacitor body were then polished to a depth of 1 / 2 in the L-axis direction. The capacitors were then fixed and placed in a vacuum chamber to obtain cross-section samples for observing the active region where the dielectric layers and internal electrode layers intersect. The active region of the cross-section sample was then measured using a transmission electron microscope (TEM) to visualize at least one layer of the dielectric layer. The TEM images were measured using a focused ion beam (Xe-FIB) at an accelerating voltage of 200 kV over an area of ​​approximately 400 nm × 400 nm, where at least one layer of the dielectric layer was visible. The TEM images of the cross-section samples were then analyzed using energy dispersive spectroscopy (EDS).

[0149] 6a to 6d are TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis images of the dielectric layer according to Example 1, and FIGS. 7a to 7d are TEM-EDS (Transmission Electron Microscope-Energy Dispersive Spectroscopy) analysis images of the dielectric layer according to Comparative Example 1.

[0150] 6a to 6d, it can be seen that in Example 1, the Dy content in the grain boundaries in the dielectric layer is low, and secondary phases containing Dy, Al, and Si are present at triple junctions, which are points where three grain boundaries meet in the dielectric layer. In contrast, it can be seen from Figures 7a to 7d that in Comparative Example 1, Dy is mainly distributed in the grain boundaries, and secondary phases containing Dy, Al, and Si are not present.

[0151] [Evaluation 2: TCC characteristics] The temperature coefficient of capacitance (TCC) characteristics of the multilayer ceramic capacitors manufactured in Example 1 and Comparative Examples 1 and 2 were measured, and the results are shown in FIG. 8 and Table 1 below.

[0152] Specifically, TCC was measured under the conditions of 1 kHz, 0.01 V, and a maintenance time of 5 minutes.

[0153] [Table 1]

[0154] FIG. 8 is a graph showing the temperature coefficient of capacitance (TCC) of the multilayer ceramic capacitors according to Example 1, Comparative Example 1, and Comparative Example 2.

[0155] 8 and Table 1, Example 1, in which a secondary phase containing Dy, Al, and Si exists at the triple points in the dielectric layer, exhibits excellent TCC characteristics, with a capacitance change of ±22% at temperatures lower and higher than room temperature, compared to Comparative Example 1, in which no secondary phase was present, and Comparative Example 2, in which a secondary Si phase was present. This indicates that temperature characteristics such as TCC are improved by suppressing the solid solution of additives such as rare earth elements. This demonstrates that the multilayer ceramic capacitor according to one embodiment has excellent TCC characteristics.

[0156] [Rating 3: Reliability] The multilayer ceramic capacitors manufactured in Example 1 and Comparative Examples 1 and 2 were measured for high temperature severe reliability (HALT) and moisture resistance reliability, and the results are shown in FIGS.

[0157] Specifically, 40 multilayer ceramic capacitors each manufactured in Example 1 and Comparative Examples 1 and 2 were prepared and mounted on a measurement board. The high temperature severe reliability (HALT) was measured using an ESPEC (PV-222, HALT) device under conditions of 125°C, 12 hours, and 9.45V, and the humidity resistance reliability was measured using an ESPEC (PR-3J, 8585) device under conditions of 85°C, relative humidity (RH) 85%, 9.45V, and 12 hours.

[0158] FIG. 9 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Example 1, FIG. 10 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Comparative Example 1, and FIG. 11 is a graph showing the high-temperature severe reliability of the multilayer ceramic capacitor according to Comparative Example 2.

[0159] 9 to 11, it can be seen that Example 1, in which a secondary phase containing Dy, Al, and Si exists at the triple points in the dielectric layer, has excellent high-temperature severe reliability at a level equal to or higher than Comparative Example 1, in which no secondary phase exists, and Comparative Example 2, in which a Si secondary phase exists. This shows that the multilayer ceramic capacitor according to an embodiment has excellent high-temperature severe reliability.

[0160] FIG. 12 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Example 1, FIG. 13 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Comparative Example 1, and FIG. 14 is a graph showing the moisture resistance reliability of the multilayer ceramic capacitor according to Comparative Example 2.

[0161] 12 to 14, it can be seen that Example 1, in which secondary phases containing Dy, Al, and Si exist at triple points in the dielectric layer, has excellent moisture resistance reliability, at a level equal to or higher than Comparative Example 1, in which no secondary phases exist, and Comparative Example 2, in which Si secondary phases exist. This shows that the multilayer ceramic capacitor according to an embodiment has excellent moisture resistance reliability.

[0162] Although the preferred embodiment of the present invention has been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and it is to be understood that these modifications also fall within the scope of the present invention. [Explanation of symbols]

[0163] 10: Dielectric grain 20: Grain boundary 30: Triple point 100: Multilayer ceramic capacitor 110: Capacitor Body 111: Dielectric layer 121: First internal electrode layer 122: Second internal electrode layer 131: 1st external electrode 132:Second external electrode

Claims

1. a capacitor body including a dielectric layer and an internal electrode layer; an external electrode disposed outside the capacitor body; the dielectric layer includes a plurality of dielectric grains, grain boundaries disposed between the plurality of dielectric grains, and triple junctions where three of the grain boundaries are disposed adjacent to each other; The multilayer ceramic capacitor, wherein the dielectric layer includes a secondary phase including Dy, Al, and Si located at the triple points.

2. 2. The multilayer ceramic capacitor according to claim 1, wherein the Dy content of the secondary phase is 15 atomic % or more and 25 atomic % or less with respect to the total amount of the secondary phase.

3. 2. The multilayer ceramic capacitor according to claim 1, wherein the secondary phase contains Al in an amount of 5 atomic % to 6 atomic % based on the total amount of the secondary phase.

4. 2. The multilayer ceramic capacitor according to claim 1, wherein the secondary phase contains Si in an amount of 70 atomic % to 80 atomic % based on the total amount of the secondary phase.

5. 2. The multilayer ceramic capacitor according to claim 1, wherein the dielectric layer contains a barium titanate-based main component and a subcomponent containing Dy, Al, and Si.

6. The multilayer ceramic capacitor according to claim 5 , wherein the minor components further include one or more elements selected from the group consisting of Tb, V, Mn, and Mg.

7. 6. The multilayer ceramic capacitor according to claim 5, wherein the Dy of the secondary phase is contained in the dielectric layer in an amount of 0.95 atomic parts to 1.15 atomic parts relative to 100 atomic parts of Ti contained in the barium titanate-based main component.

8. 6. The multilayer ceramic capacitor according to claim 5, wherein the secondary phase Al is contained in the dielectric layer in an amount of 0.30 atomic parts or more and 0.34 atomic parts or less per 100 atomic parts of Ti contained in the barium titanate-based main component.

9. 6. The multilayer ceramic capacitor according to claim 5, wherein the secondary phase Si is contained in the dielectric layer in an amount of 4.0 atomic parts to 4.4 atomic parts per 100 atomic parts of Ti contained in the barium titanate-based main component.

10. The multilayer ceramic capacitor according to claim 1 , wherein the area occupied by the secondary phase is 0.15% to 1% of the total area of ​​the dielectric layer.

11. A step of preparing a dielectric slurry by mixing a barium titanate-based main component powder with subcomponent powders including a Dy-containing compound, an Al-containing compound, and a Si-containing compound; preparing a dielectric green sheet using the dielectric slurry, and forming a conductive paste layer on a surface of the dielectric green sheet; laminating the dielectric green sheets on which the conductive paste layers are formed 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; and forming an external electrode on one surface of the capacitor body; the dielectric layer includes a plurality of dielectric grains, grain boundaries disposed between the plurality of dielectric grains, and triple junctions where three of the grain boundaries are disposed adjacent to each other; The method for manufacturing a multilayer ceramic capacitor, wherein the dielectric layer includes a secondary phase including Dy, Al, and Si arranged at the triple junction.

12. The method for producing a multilayer ceramic capacitor according to claim 11, wherein the Dy-containing compound is mixed in an amount of 0.5 to 1.2 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

13. The method for producing a multilayer ceramic capacitor according to claim 11, wherein the Al-containing compound is mixed in an amount of 0.1 to 0.5 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

14. The method for producing a multilayer ceramic capacitor according to claim 11, wherein the Si-containing compound is mixed in an amount of 1 part by mol to 5 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

15. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the auxiliary component powder further comprises at least one selected from the group consisting of a Tb-containing compound, a V-containing compound, a Mn-containing compound, and a Mg-containing compound.

16. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the firing is performed for a duration of 10 seconds to 3 minutes.

17. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the firing is performed at a temperature of 1160°C or higher and 1250°C or lower.

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