Multilayer ceramic capacitor and method of fabricating the same

Abstract

To provide a multilayer ceramic capacitor with excellent accelerated life reliability.SOLUTION: A multilayer ceramic capacitor and is a method of fabricating the same are provided, the capacitor comprising: a capacitor body including a dielectric layer and an internal electrode layer; and an external electrode disposed outside the capacitor body. The internal electrode layer includes at least one lost portion defined as a region in which continuity of the internal electrode layer is disconnected, and the lost portion includes a Mg concentrated region containing magnesium (Mg) as a main element. The dielectric layer includes an interface adjacent region defined to be a region from the interface between the dielectric layer and the internal electrode layer to a depth surface of 80 nm to 100 nm into the dielectric layer, and the interface adjacent region contains magnesium (Mg). The magnesium (Mg) contained in the interface adjacent region of the dielectric layer has a lower atom% content than the magnesium (Mg) contained in the Mg concentrated region of the lost portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

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

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

[0004] Recently, there is a strong demand for high performance and miniaturization of multilayer ceramic capacitors. To realize high-capacity and small-sized multilayer ceramic capacitors, it is necessary to make the dielectric layers thinner. To ensure reliability characteristics under the design conditions of the thin dielectric layer, uniform distribution of additives and grain growth control technology are important, and distribution of additive elements and content ratio control that contribute to improving reliability are important. Summary of the Invention [Problem to be solved by the invention]

[0005] One embodiment provides a multilayer ceramic capacitor with excellent accelerated life 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 arranged on the outside of the capacitor body, the internal electrode layer including at least one defect portion defined by a region where the continuity of the internal electrode layer is interrupted, the defect portion including an Mg-enriched region including magnesium (Mg) as a main element, the dielectric layer including an interface vicinity region defined by a region from an interface between the dielectric layer and the internal electrode layer to a depth surface of 80 nm to 100 nm into the dielectric layer, the interface vicinity region including magnesium (Mg), and the magnesium (Mg) included in the interface vicinity region of the dielectric layer has a lower atomic % content than the magnesium (Mg) included in the Mg-enriched region of the defect portion.

[0008] The magnesium (Mg) contained in the Mg-enriched region of the defect portion can be contained in an amount of 1.6 atomic % to 11.1 atomic % with respect to the total amount of components in the Mg-enriched region.

[0009] The Mg-enriched region of the defect may further include barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or combinations thereof.

[0010] The Mg-enriched region of the defect portion may contain the titanium (Ti), and the magnesium (Mg) contained in the Mg-enriched region of the defect portion is contained in an amount of 12.68 to 22,000 molar parts per 100 molar parts of the titanium (Ti). can .

[0011] The Mg-enriched region of the defect portion may contain the nickel (Ni), and the magnesium (Mg) contained in the Mg-enriched region of the defect portion is contained in an amount of 4.75 to 71.58 molar parts per 100 molar parts of the nickel (Ni). can .

[0012] The magnesium (Mg) contained in the Mg-enriched region of the defect portion is contained in a molar ratio of 1.010 to 13.701 relative to the magnesium (Mg) contained in the interface vicinity region of the dielectric layer. can .

[0013] The magnesium (Mg) contained in the Mg-enriched region of the defect can combine with at least one of nickel (Ni) and oxygen (O) to form a secondary phase.

[0014] The magnesium (Mg) contained in the interface vicinity region of the dielectric layer is 0.8 atomic % to 4.2 atomic % with respect to the total amount of components in the interface vicinity region. can .

[0015] The near-interface region of the dielectric layer may further include barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or combinations thereof.

[0016] The interface vicinity region of the dielectric layer may contain the titanium (Ti), and the magnesium (Mg) contained in the interface vicinity region of the dielectric layer is contained in an amount of 5.0 to 29.7 molar parts per 100 molar parts of the titanium (Ti). can .

[0017] Another embodiment of the present invention includes the steps of: preparing a dielectric slurry by mixing a barium titanate-based main component powder and a subcomponent powder including a magnesium (Mg)-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, The internal electrode layer includes at least one defect defined by a region where the continuity of the internal electrode layer is interrupted, the defect includes an Mg-concentrated region containing magnesium (Mg) as a main element, the dielectric layer includes an interface vicinity region defined by a region from an interface between the dielectric layer and the internal electrode layer to a depth of 80 nm to 100 nm into the dielectric layer, the interface vicinity region includes magnesium (Mg), and the magnesium (Mg) contained in the interface vicinity region of the dielectric layer has a lower atomic % content than the magnesium (Mg) contained in the Mg-concentrated region of the defect.

[0018] The magnesium (Mg)-containing compound is mixed in an amount of 0.01 to 3 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder. can .

[0019] The secondary component powder may further include a dysprosium (Dy)-containing compound, a terbium (Tb)-containing compound, a manganese (Mn)-containing compound, a vanadium (V)-containing compound, an aluminum (Al)-containing compound, a silicon (Si)-containing compound, a tin (Sn)-containing compound, or a combination thereof.

[0020] With respect to 100 mol parts of the barium titanate-based main component powder, the dysprosium (Dy)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, the terbium (Tb)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, the manganese (Mn)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, the vanadium (V)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, the aluminum (Al)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, the silicon (Si)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts, and the tin (Sn)-containing compound may be contained in an amount of 0.01 mol parts to 5 mol parts. can .

[0021] The conductive paste layer is made of a conductive paste containing nickel (Ni). can . Effect of the Invention

[0022] The multilayer ceramic capacitor according to an embodiment has improved accelerated life reliability due to an increase in potential barrier height at the interface between the dielectric layer and the internal electrode layer. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view illustrating a multilayer ceramic capacitor according to an embodiment; [Diagram 2] 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. [Diagram 3] 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. [Figure 4] 3 is a schematic diagram showing a portion of the active area A in FIG. 2. [Figure 5A] 4 is a TEM-EDS analysis image of an active area of ​​the multilayer ceramic capacitor according to Example 1. [Figure 5B] 4 is a TEM-EDS analysis image of an active area of ​​the multilayer ceramic capacitor according to Comparative Example 1. [Figure 6] 4 is an EDS line profile analysis graph for an interface between a dielectric layer and an internal electrode layer of the multilayer ceramic capacitor according to Example 1. [Figure 7] 4 is a graph showing the accelerated life reliability of the multilayer ceramic capacitor according to Example 1. [Figure 8] 1 is a graph showing the accelerated life reliability of the multilayer ceramic capacitor according to Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention will be described in detail so that a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. In the drawings, parts that are unnecessary for the explanation are omitted in order to clearly explain the present invention, and the same reference numerals are used for the same or similar components throughout the specification. In addition, in the accompanying drawings, some components are exaggerated, omitted, or shown in a schematic manner, and the size of each component does not completely reflect the actual size.

[0025] It should be understood that the attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and do not limit the technical ideas disclosed in this specification, but include all modifications, equivalents, or alternatives included in the idea and technical scope of the present invention.

[0026] 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.

[0027] In addition, when a part such as a layer, film, region, or plate is said to be "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where 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. Furthermore, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" the opposite direction of gravity.

[0028] It should be understood that, throughout the specification, the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Thus, when a part "comprises" 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.

[0029] 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.

[0030] Furthermore, throughout the specification, when the term "connected" is used, this does not only mean that two or more components are directly connected, but also that two or more components are indirectly connected via other components, and can mean not only that they are physically connected but also that they are electrically connected, or that they are referred to by different names depending on their position or function.

[0031] Hereinafter, a multilayer ceramic capacitor according to an embodiment will be described with reference to FIGS.

[0032] FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to one embodiment, FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line II' in FIG. 1, FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor taken along line II-II' in FIG. 1, and FIG. 4 is a schematic view showing a portion of an active area A in FIG. 2.

[0033] The L axis, W axis, and T axis shown in Figs. 1 to 4 respectively indicate the longitudinal direction, width direction, and thickness direction of the capacitor body 110. Here, the thickness direction (T axis direction) may be a direction perpendicular to the wide surface (main surface) of the sheet-shaped component, and may be used in the same concept as the lamination direction in which the dielectric layers 111 are laminated, for example. The longitudinal direction (L axis direction) is a direction extending in parallel to the wide surface (main surface) of the sheet-shaped component and approximately perpendicular to the thickness direction (T axis direction), and may be, for example, 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 in parallel to the wide surface (main surface) of the sheet-shaped component and approximately perpendicular to the thickness direction (T axis direction) and the longitudinal direction (L axis direction), and the length of the longitudinal direction (L axis direction) of the sheet-shaped component is longer than the length of the width direction (W axis direction).

[0034] 1 to 4, a multilayer ceramic capacitor 100 according to an embodiment includes a capacitor body 110 and external electrodes 131, 132 disposed on the outer side of the capacitor body 110. The external electrodes 131, 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).

[0035] Capacitor Body For example, the capacitor body 110 may have a substantially hexahedral shape.

[0036] For the convenience of describing one embodiment, in capacitor body 110, the two surfaces that face each other in the thickness direction (T-axis direction) are defined as the first surface and the second surface, and the two surfaces that are connected to the first surface and the second surface, the two surfaces that face each other in the longitudinal 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 the two surfaces that face each other in the width direction (W-axis direction) are defined as the fifth surface and the sixth surface.

[0037] As an example, the first surface of the lower surface is the surface facing the mounting direction. The first to sixth surfaces may be flat, but the embodiment is not limited to this. For example, the first to sixth surfaces may be curved surfaces with a convex center, and the corners that are the boundaries between the surfaces may be rounded.

[0038] 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 figure of this embodiment.

[0039] 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 between them.

[0040] At this time, the boundaries between the adjacent dielectric layers 111 of the capacitor body 110 are integrated to such an extent that it is difficult to confirm them without using a scanning electron microscope (SEM).

[0041] The capacitor body 110 may include an active area A. The active area is a portion that contributes to forming the capacitance of the multilayer capacitor 100. As an example, the active area may be an area where the first internal electrode 121 or the second internal electrode 122 stacked along the thickness direction (T-axis direction) overlaps.

[0042] Additionally, the capacitor body 110 may further include a cover region and a side margin region.

[0043] The cover regions are margins in the thickness direction and may be located in the thickness direction (T-axis direction) on the first and second surface sides of the active region A. Such a cover region may be a single dielectric layer 111 or two or more dielectric layers 111 laminated on the upper and lower surfaces of the active region A, respectively.

[0044] The side margin regions are widthwise margins and may be located on the fifth and sixth surfaces of the active region in the widthwise direction (W-axis direction). Such side margin regions are formed by applying a conductive paste layer for an internal electrode to only a part of the surface of the dielectric green sheet when applying the conductive paste layer to the surface of the dielectric green sheet, laminating dielectric green sheets on both sides of the surface of the dielectric green sheet without applying the conductive paste layer, and then firing the laminate.

[0045] The cover region and the side margin region serve to prevent the first internal electrode 121 and the second internal electrode 122 from being damaged by physical or chemical stress.

[0046] The first internal electrode 121 and the second internal electrode 122 are electrodes having different polarities and are alternately arranged so as to face each other along the T-axis direction across the dielectric layer 111, and one end can be exposed through the third and fourth surfaces of the capacitor body 110, respectively.

[0047] The first internal electrode 121 and the second internal electrode 122 can be electrically insulated from each other by a dielectric layer 111 disposed therebetween.

[0048] Ends of the first internal electrode 121 and the second internal electrode 122 alternately exposed through the third and fourth surfaces of the capacitor body 110 can be electrically connected to the first external electrode 131 and the second external electrode 132, respectively.

[0049] The first internal electrode 121 and the second internal electrode 122 include a conductive metal, and may include, for example, a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy thereof, for example, an Ag-Pd alloy.

[0050] Furthermore, the first internal electrode 121 and the second internal electrode 122 may contain dielectric particles having the same composition as the ceramic material contained in the dielectric layer 111 .

[0051] The first internal electrode 121 and the second internal electrode 122 are formed using a conductive paste containing a conductive metal. The conductive paste can be printed by screen printing or gravure printing.

[0052] 4, the internal electrode layers 121 and 122 according to an embodiment include at least one missing portion L defined as a region where the continuity of the internal electrode layers is interrupted. For example, the number of missing portions L may be two or more in one internal electrode layer, for example, 2 to 300, for example, 2 to 180. As an example, the number of missing portions L may be 2 to 300 based on the LT plane (longitudinal-thickness plane), and 2 to 180 based on the WT plane (width-thickness plane).

[0053] The capacitor body 110 is formed by firing a laminate in which a plurality of dielectric layers and internal electrode layers are stacked in the thickness direction (T-axis direction). At this time, the metal-based internal electrode layers are fired at a relatively lower temperature than the ceramic dielectric layers, so that the internal electrode layers may be overfired when the dielectric layers are fired, causing excessive shrinkage and breakage. As a result, the internal electrode layers 121 and 122 have the portions where such breakage occurs, i.e., missing portions L.

[0054] The defect portion L includes an Mg-enriched region C containing magnesium (Mg) as a main element. Specifically, the defect portion L may contain various components due to the movement and diffusion of nickel (Ni) and the like used as a main component when forming the internal electrode layers 121, 122, and the main and subcomponents used when forming the dielectric layer 111. The Mg-enriched region C containing magnesium (Mg) as a main element is present in such a defect portion L. The Mg-enriched region C may be a region in the defect portion L where the concentration of the Mg element increases.

[0055] According to an embodiment, when the Mg-enriched region C exists in the defect portion L of the internal electrode layer 121, 122, it serves to reduce the Mg concentration in the dielectric layer 111 at the interface between the dielectric layer 111 and the internal electrode layer 121, 122, thereby suppressing the phenomenon in which the Mg element in the dielectric is excessively dissolved as an acceptor. In addition, since the oxygen vacancy concentration is reduced by suppressing the excessive dissolution of Mg in the dielectric, the potential barrier height at the interface between the dielectric layer 111 and the internal electrode layer 121, 122 is increased, thereby improving the accelerated life reliability.

[0056] Specifically, the Mg-enriched region C may contain magnesium (Mg) in an amount of 1.6 atomic % to 11.1 atomic % with respect to the total amount of components present in the Mg-enriched region C, for example, 2.0 atomic % to 10.0 atomic %. When the Mg-enriched region C has magnesium (Mg) present in the above concentration range, the potential barrier height at the interface between the dielectric layer and the internal electrode layer is increased, thereby improving the accelerated life reliability.

[0057] In addition, the Mg-enriched region C of the defect portion L may further include barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or a combination thereof. Here, barium (Ba) and titanium (Ti) are derived from the main component material used when forming the dielectric layer 111, and may be components that have migrated and diffused to the defect portion L of the internal electrode layers 121 and 122. In addition, dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), and tin (Sn) are derived from the auxiliary component material used when forming the dielectric layer 111, and may be components that have migrated and diffused to the defect portion L of the internal electrode layers 121 and 122. Nickel (Ni) may be a component derived from the main component material used when forming the internal electrode layers 121, 122.

[0058] As an example, the Mg-enriched region C of the defect portion L can contain magnesium (Mg) and titanium (Ti). In this case, the magnesium (Mg) contained in the Mg-enriched region C may be 12.68 molar parts or more relative to 100 molar parts of titanium (Ti), for example, 12.68 molar parts to 22000 molar parts, 15 molar parts to 20000 molar parts. When magnesium (Mg) is contained within the Mg-enriched region C within the above content range, excellent accelerated life reliability can be obtained due to an increase in the height of the potential barrier at the interface between the dielectric layer and the internal electrode layer.

[0059] As another example, the Mg-enriched region C of the defect portion L may contain magnesium (Mg) and nickel (Ni). In this case, the magnesium (Mg) contained in the Mg-enriched region C is 4.75 to 71.58 molar parts, for example, 5.0 to 60.0 molar parts, relative to 100 molar parts of nickel (Ni). When magnesium (Mg) is contained within the Mg-enriched region C within the above content range, excellent accelerated life reliability can be achieved due to an increase in the height of the potential barrier at the interface between the dielectric layer and the internal electrode layer.

[0060] The magnesium (Mg) contained in the Mg-enriched region C of the defect portion L is contained in a molar ratio of 1.010 to 13.701 relative to the magnesium (Mg) contained in the interface vicinity region R of the dielectric layer 111, for example, in a molar ratio of 1.1 to 11.0. When the molar ratio of magnesium (Mg) in the Mg-enriched region C and the interface vicinity region R is within the above range, the phenomenon in which the Mg element in the dielectric layer 111 is excessively dissolved as an acceptor is suppressed, thereby reducing the oxygen vacancy concentration. As a result, the potential barrier height at the interface between the dielectric layer 111 and the internal electrode layers 121 and 122 is increased, thereby improving the accelerated life reliability.

[0061] Magnesium (Mg) contained in the Mg-enriched region C of the defect portion L can combine with at least one of nickel (Ni) and oxygen (O) to form a secondary phase. When magnesium (Mg) takes the form of a secondary phase together with at least one of nickel (Ni) and oxygen (O), it serves to reduce the Mg concentration in the dielectric layer 111 at the interface between the dielectric layer 111 and the internal electrode layers 121 and 122, thereby making it possible to suppress the phenomenon in which the Mg element in the dielectric layer 111 becomes excessively dissolved as an acceptor.

[0062] The average thickness of the first internal electrode 121 and the second internal electrode 122 may be 0.1 μm to 2 μm. This is determined by taking the center point of the first internal electrode 121 or the second internal electrode 122 in the longitudinal direction (L-axis direction) or width direction (W-axis direction) as a reference point in a scanning electron microscope (SEM) image of the cross-sectional sample measured as described above, and calculating the arithmetic average value of the thicknesses of the first internal electrode 121 or the second internal electrode 122 at 10 points spaced apart by a predetermined distance from the reference point. 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 first internal electrode 121 or the second internal electrode 122, and if all 10 points are not located within the first internal electrode 121 or the second internal electrode 122, the position of the reference point can be changed or the interval between the 10 points can be adjusted.

[0063] The dielectric layer 111 according to one embodiment may include a barium titanate based main component including barium (Ba) and titanium (Ti).

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

[0065] As an example, the main component of barium titanate is BaTiO 3 , Ba(Ti,Zr)O 3 , Ba(Ti,Sn)O 3 , (Ba,Ca)TiO 3 , (Ba,Ca)(Ti,Zr)O 3 , (Ba,Ca)(Ti,Sn)O 3 , (Ba,Sr)TiO 3 , (Ba,Sr)(Ti,Zr)O 3 , (Ba,Sr)(Ti,Sn)O 3 , or a combination thereof.

[0066] The dielectric layer 111 may further include a minor component containing magnesium (Mg). In addition to magnesium (Mg), the minor component may further include, for example, dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), or a combination thereof, but is not limited thereto.

[0067] The dielectric layer 111 may include an interface vicinity region R defined as a region from the interface between the dielectric layer 111 and the internal electrode layers 121, 122 to a depth surface of 80 nm to 100 nm into the dielectric layer 111. The interface vicinity region R may be located adjacent to the Mg concentrated region C of the defect portion L, for example.

[0068] The interface vicinity region R of the dielectric layer 111 contains magnesium (Mg).

[0069] The magnesium (Mg) contained in the interface vicinity region R of the dielectric layer 111 may have a lower atomic % content than the magnesium (Mg) contained in the Mg enriched region C of the defect portion L. This is a result of reducing the Mg concentration in the dielectric layer 111 in the interface vicinity region R of the dielectric layer 111 adjacent to the Mg enriched region C by forming the Mg enriched region C of the defect portion L. As a result, when the magnesium (Mg) contained in the interface vicinity region R has a lower atomic % content than the magnesium (Mg) contained in the Mg enriched region C, it is possible to suppress the phenomenon in which the Mg element in the dielectric layer 111 is excessively dissolved as an acceptor. In addition, the reduction in oxygen vacancy concentration due to the suppression of the excessive Mg solid solution in the dielectric layer 111 leads to an increase in the potential barrier height at the interface between the dielectric layer 111 and the internal electrode layers 121 and 122, and the accelerated life reliability can be improved.

[0070] The interface vicinity region R of the dielectric layer 111 may contain magnesium (Mg) at 0.8 atomic % to 4.2 atomic % with respect to the total amount of components present in the interface vicinity region R, for example, 1.0 atomic % to 3.5 atomic %. This is because the Mg concentration in the dielectric layer 111 is reduced in the interface vicinity region R of the dielectric layer 111 adjacent to the Mg concentrated region C by forming the Mg concentrated region C in the missing portion L of the internal electrode layers 121, 122. As a result, when the magnesium (Mg) in the interface vicinity region R has the above content range, it is possible to suppress the phenomenon in which the Mg element in the dielectric layer 111 is excessively dissolved as an acceptor, which leads to an increase in the height of the potential barrier at the interface, thereby improving the accelerated life reliability.

[0071] The interface vicinity region R of the dielectric layer 111 may further contain barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or a combination thereof. The origin of the above components is the same as that of the components contained in the Mg-enriched region C of the defect portion L.

[0072] As an example, the interface vicinity region R of the dielectric layer 111 may contain magnesium (Mg) and titanium (Ti). In this case, the magnesium (Mg) contained in the interface vicinity region R is 5.0 to 29.7 molar parts, for example, 8.0 to 25.0 molar parts, relative to 100 molar parts of titanium (Ti). When magnesium (Mg) is contained within the interface vicinity region R within the above content range, the height of the potential barrier at the interface between the dielectric layer and the internal electrode layer is increased, thereby providing excellent accelerated life reliability.

[0073] The average thickness (average length in the T-axis direction) of the dielectric layer 111 may be 0.2 μm to 8.0 μm, for example, 2.4 μm to 7.8 μm. When the average thickness of the dielectric layer 111 is within the above range, the reliability of the multilayer ceramic capacitor is excellent. This is determined by taking the center point of the dielectric layer 111 in the longitudinal direction (L-axis direction) or width direction (W-axis direction) as a reference point in a scanning electron microscope (SEM) image of the cross-sectional sample measured as described above, and calculating the arithmetic average value of the thickness of the dielectric layer 111 at 10 points spaced apart from the reference point by a predetermined distance. 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 of the 10 points must be located within the dielectric layer 111, and if all of the 10 points are not located within the dielectric layer 111, the position of the reference point can be changed or the interval between the 10 points can be adjusted.

[0074] 4 is shown for understanding the defect portion L, the Mg-enriched region C, and the interface vicinity region R, and only a portion of the defect portion L, the Mg-enriched region C, and the interface vicinity region R is shown for convenience, and the present invention is not limited to this drawing. In other words, all the regions where the continuity is interrupted in the internal electrode layers 121 and 122 may be the defect portion L, and all the regions in the defect portion L that contain the Mg element as a main element or where the concentration of the Mg element increases may be the Mg-enriched region C, and the interface vicinity region R may be present anywhere where the interface between the dielectric layer 111 and the internal electrode layers 121 and 122 exists, and may be present on the other surface in addition to one surface of one internal electrode layer.

[0075] According to one embodiment, the Mg element and content present in the interface vicinity region R between the Mg-concentrated region C formed in the defect portion L of the internal electrode layers 121, 122 and the dielectric layer 111 are confirmed by TEM-EDS (transmission electron microscopy-energy dispersive spectroscopy) analysis.

[0076] Specifically, the multilayer ceramic capacitor 100 is placed in an epoxy mixture and cured, and then the L-axis and T-axis direction surfaces (LT surfaces) of the capacitor body 110 are polished to a depth of 1 / 2 in the W-axis direction, and then fixed and maintained in a vacuum atmosphere chamber to obtain a cross-sectional sample so that the active area A where the dielectric layer 111 and the internal electrode layers 121 and 122 intersect can be observed. Next, the active area A of the cross-sectional sample, for example, the upper, center, and side portions of the active area, can be measured with a transmission electron microscope (TEM). The transmission electron microscope is performed using a Xe-FIB (focused ion beam) under conditions of an acceleration voltage of 200 kV and an analysis magnification of 110k times, and the dielectric layer 111 and the internal electrode layers 121 and 122 can be measured so that at least one layer, for example, 3 to 100 layers and 5 to 50 layers, respectively, can be seen. Next, the presence and content of magnesium (Mg) element can be confirmed by EDS analysis in the transmission electron microscope (TEM) image of the measured cross-sectional sample. Specifically, the formation of an Mg-enriched region C can be confirmed in the missing portion L of the internal electrode layers 121, 122, and the content of magnesium (Mg) element present in the region R near the interface between the Mg-enriched region C and the dielectric layer 111 can be confirmed. The content of the Mg element may be an average value measured at at least one point, for example, two points, three points, or five points, in each of the upper, center, and side portions of the active area.

[0077] external electrode The first external electrode 131 and the second external electrode 132 are provided with voltages of different polarities and are electrically connected to exposed portions of the first internal electrode 121 and the second internal electrode 122, respectively.

[0078] With this configuration, when a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charges are stored between the opposing first internal electrode 121 and second internal electrode 122. At this time, the capacitance of the multilayer ceramic capacitor 100 is proportional to the overlap area of ​​the first internal electrode 121 and the second internal electrode 122 that overlap each other along the T-axis direction in the active region.

[0079] The first external electrode 131 and the second external electrode 132 may each include first and second connection portions arranged on the third and fourth surfaces of the capacitor body 110 and connected to the first internal electrode 121 and the second internal electrode 122, respectively, and first and second band portions arranged at corners where the third and fourth surfaces of the capacitor body 110 meet the first and second surfaces or the fifth and sixth surfaces.

[0080] The first and second band portions may extend from the first and second connection portions to parts of the first and second faces or the fifth and sixth faces of the capacitor body 110. The first and second band portions may serve to improve the bonding strength between the first external electrode 131 and the second external electrode 132.

[0081] 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 arranged to cover the sintered metal layer, and a plating layer arranged to cover the conductive resin layer.

[0082] The sintered metal layer can include a conductive metal and glass.

[0083] The conductive metal may include copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), lead (Pb), alloys thereof, or combinations thereof, for example, copper (Cu) may include copper (Cu) alloys. When the conductive metal includes copper, the metal other than copper is included in an amount of 5 molar parts or less per 100 molar parts of copper.

[0084] The glass may include a mixed oxide composition, such as one or more selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide. The transition metal may be selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni), the alkali metal may be selected from the group consisting of lithium (Li), sodium (Na), and potassium (K), and the alkaline earth metal may be one or more selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0085] 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.

[0086] The conductive resin layer extends on 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 arranged extending on the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 is longer than the length of the region (i.e., band portion) where the sintered metal layer is arranged extending on the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. In other words, the conductive resin layer is formed on the sintered metal layer to completely cover the sintered metal layer.

[0087] The conductive resin layer includes a resin and a conductive metal.

[0088] The resin contained in the conductive resin layer is not particularly limited as long as it has bonding and impact absorbing properties and can be mixed with the conductive metal powder to form a paste, and may include, for example, a phenolic resin, an acrylic resin, a silicone resin, an epoxy resin, or a polyimide resin.

[0089] The conductive metal contained in the conductive resin layer serves to electrically connect with the first internal electrode 121 and the second internal electrode 122 or the sintered metal layer.

[0090] The conductive metal contained in the conductive resin layer may have a spherical shape, a flake shape, or a combination thereof, that is, the conductive metal may be only flake-shaped, only spherical, or a mixture of flake-shaped and spherical shapes.

[0091] Here, the term "spherical" may include shapes that are not completely spherical, and may include shapes in which the ratio of the major axis to the minor axis (major axis / minor axis) is 1.45 or less. The term "flaky powder" refers to a powder having a flat and elongated shape, and is not particularly limited, and may include shapes in which the ratio of the major axis to the minor axis (major axis / minor axis) is 1.95 or more, for example.

[0092] 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.

[0093] The plating layer may include nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), or lead (Pb) alone or in combination with an alloy thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or may be a layer in which a nickel (Ni) plating layer and a tin (Sn) plating layer are sequentially laminated, or a layer in which a tin (Sn) plating layer, a nickel (Ni) plating layer, and a tin (Sn) plating layer are sequentially laminated. The plating layer may include a plurality of nickel (Ni) plating layers and / or a plurality of tin (Sn) plating layers.

[0094] The plating layer can improve the mountability of the multilayer ceramic capacitor 100 to a substrate, structural reliability, durability against the outside, heat resistance, and equivalent series resistance (ESR).

[0095] A method for manufacturing the multilayer ceramic capacitor 100 according to an embodiment will now be described.

[0096] Manufacturing method of multilayer ceramic capacitor The multilayer ceramic capacitor 100 according to one embodiment can be manufactured through the steps of: preparing a dielectric slurry by mixing a barium titanate-based main component powder and a secondary component powder including a magnesium (Mg)-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.

[0097] First, a barium titanate-based main component powder and a subcomponent powder containing a magnesium (Mg)-containing compound are mixed together to produce a dielectric slurry.

[0098] The barium titanate-based main component powder is the same as the barium titanate-based main component contained in the dielectric layer, and therefore a description thereof will be omitted here.

[0099] The magnesium (Mg)-containing compound is mixed in an amount of 0.01 to 3 mol parts, for example 0.05 to 1.5 mol parts, relative to 100 mol parts of the barium titanate-based main component powder. When the magnesium (Mg)-containing compound is mixed within the above content range, an Mg-enriched region C is formed in the defect portion L of the internal electrode layer, thereby reducing the Mg concentration in the dielectric layer at the interface between the dielectric layer and the internal electrode layer. Therefore, the phenomenon in which the Mg element in the dielectric layer is excessively dissolved as an acceptor is suppressed, thereby reducing the oxygen vacancy concentration and increasing the height of the potential barrier at the interface between the dielectric layer and the internal electrode layer, thereby obtaining a multilayer ceramic capacitor with excellent accelerated life reliability.

[0100] The auxiliary component powder may further include a dysprosium (Dy)-containing compound, a terbium (Tb)-containing compound, a manganese (Mn)-containing compound, a vanadium (V)-containing compound, an aluminum (Al)-containing compound, a silicon (Si)-containing compound, a tin (Sn)-containing compound, or a combination thereof.

[0101] The auxiliary component powder may be an oxide or salt compound, or may be used in the form of a sol dispersed in an organic solvent.

[0102] The dysprosium (Dy)-containing compound is contained in an amount of 0.01 to 5 mol parts relative to 100 mol parts of the barium titanate-based main component powder, the terbium (Tb)-containing compound is contained in an amount of 0.01 to 5 mol parts relative to 100 mol parts of the barium titanate-based main component powder, the manganese (Mn)-containing compound is contained in an amount of 0.01 to 5 mol parts relative to 100 mol parts of the barium titanate-based main component powder, and the vanadium (V)-containing compound is contained in an amount of 0.01 to 5 mol parts relative to 100 mol parts of the barium titanate-based main component powder. The auxiliary component powders are contained in an amount of 0.01 to 5 molar parts relative to 100 molar parts of the component powders, the aluminum (Al)-containing compound is contained in an amount of 0.01 to 5 molar parts relative to 100 molar parts of the barium titanate-based main component powder, the silicon (Si)-containing compound is contained in an amount of 0.01 to 5 molar parts relative to 100 molar parts of the barium titanate-based main component powder, and the tin (Sn)-containing compound is contained in an amount of 0.01 to 5 molar parts relative to 100 molar parts of the barium titanate-based main component powder. When the auxiliary component powders are contained within the above content ranges, a multilayer ceramic capacitor having high capacity, high reliability, and excellent voltage resistance characteristics can be obtained.

[0103] The dielectric slurry may be prepared by additionally mixing additives such as a dispersant, a binder, a plasticizer, a lubricant, an antistatic agent, and a solvent.

[0104] The dispersant may include, for example, a phosphate-based dispersant, a polycarboxylic acid-based dispersant, or a combination thereof. The dispersant is 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 main component powder. 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.

[0105] The binder may be, for example, an acrylic resin, a polyvinyl butyl resin, a polyvinyl acetal resin, an ethyl cellulose resin, etc. The binder is 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 main component powder. 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.

[0106] The plasticizer may be, for example, a phthalic acid compound such as dioctyl phthalate, benzyl butyl phthalate, dibutyl phthalate, dihexyl phthalate, di(2-ethylhexyl) phthalate, or di(2-ethylbutyl) phthalate; an adipic acid compound such as dihexyl adipate or di(2-ethylhexyl) adipate; a glycol compound such as ethylene glycol, diethylene glycol, or triethylene glycol; or a glycol ester compound such as triethylene glycol dibutyrate, triethylene glycol di(2-ethylbutyrate), or triethylene glycol di(2-ethylhexanoate). The plasticizer is added in an amount of 0.1 to 20 parts by weight, for example, 1 to 10 parts by weight, relative to 100 parts by weight of the barium titanate-based main component powder. 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.

[0107] The solvent may be an aqueous solvent such as water; an alcoholic solvent such as ethanol, methanol, benzyl alcohol, or methoxyethanol; a glycol solvent such as ethylene glycol or diethylene glycol; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone; an ester solvent such as butyl acetate, ethyl acetate, carbitol acetate, or butyl carbitol acetate; an ether solvent such as methyl cellosolve, ethyl cellosolve, butyl ether, or tetrahydrofuran; or an aromatic solvent such as benzene, toluene, or xylene. The solvent may be an alcoholic solvent or an aromatic solvent, for example, in consideration of the solubility and dispersibility of various additives contained in the dielectric slurry. The solvent is mixed in an amount of 50 parts by weight to 1000 parts by weight, for example, 100 parts by weight to 500 parts by weight, relative to 100 parts by weight of the barium titanate-based main component powder. When the solvent is mixed within the above content range, the dielectric slurry components are sufficiently mixed, and the solvent can be easily removed thereafter.

[0108] A wet ball mill or stirring mill can be used to mix the barium titanate-based main component powder and subcomponent powder. When using zirconia balls in a wet ball mill, wet mixing can be performed for 8 to 48 hours or 10 to 24 hours using multiple zirconia balls with diameters of 0.1 mm to 10 mm.

[0109] The prepared dielectric slurry is formed into a dielectric layer after firing.

[0110] The produced dielectric slurry can be molded into a sheet shape using a tape molding method such as a doctor blade method or a calendar roll method, for example, a head-discharging on-roll molding coater, and then the molded body can be dried to obtain a dielectric green sheet.

[0111] To form a conductive paste layer that will become an internal electrode layer after firing, a conductive paste can be manufactured by mixing a conductive powder made of a conductive metal or its alloy, a binder, and a solvent. If necessary, barium titanate powder can be mixed in as a co-material. The co-material can suppress the sintering of the conductive powder during the firing process. The conductive paste is applied in a predetermined pattern to the surface of the dielectric green sheet by various printing methods such as screen printing or transfer methods to form a conductive paste layer.

[0112] The conductive powder may include nickel (Ni) or a nickel (Ni) alloy.

[0113] Next, the dielectric green sheets on which the internal electrode patterns are formed are laminated in a plurality of layers, and then pressed in the lamination direction to manufacture a dielectric green sheet laminate. At this time, the dielectric green sheets and the internal electrode patterns can be laminated so that the dielectric green sheets are located on the upper and lower surfaces of the dielectric green sheet laminate in the lamination direction.

[0114] The manufactured dielectric green sheet laminate may be selectively cut into a predetermined size by dicing or the like.

[0115] Furthermore, the dielectric green sheet laminate can be solidified and dried to remove plasticizers, etc., as necessary, and after solidification and drying, can be barrel polished using a horizontal centrifugal barrel machine, etc. In barrel polishing, the dielectric green sheet laminate is placed in a barrel container together with media and polishing liquid, and unnecessary parts such as burrs generated during cutting can be polished by applying rotational motion, vibration, etc. to the barrel container. Furthermore, after barrel polishing, the dielectric green sheet laminate can be washed with a cleaning liquid such as water and dried.

[0116] The dielectric greensheet laminate can then be debindered and fired to produce a capacitor body.

[0117] The binder removal treatment conditions can be appropriately adjusted depending on the components of the dielectric layers and the internal electrode layers. For example, the temperature rise rate during the binder removal treatment may be 5°C / hour to 300°C / hour, the support temperature may be 180°C to 400°C, and the temperature maintenance time may be 0.5 hours to 24 hours. The atmosphere during the binder removal treatment may be air or a reducing atmosphere.

[0118] The firing conditions can be appropriately adjusted depending on the composition of the main components of the dielectric layers and the main components of the internal electrodes. For example, firing is performed at a temperature of 1100°C to 1400°C, for example, 1200°C to 1350°C. The firing is performed for 0.5 hours to 8 hours, for example, 1 hour to 3 hours. The firing is performed in a reducing atmosphere, for example, an atmosphere of a humidified mixed gas of nitrogen and hydrogen. When the internal electrodes contain nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere is 1.0×10 -14 MPa~1.0×10 -10 It may be MPa.

[0119] After the firing treatment, annealing can be carried out as necessary. Annealing is a treatment for reoxidizing the dielectric layer, and annealing can be carried out when the firing treatment is carried out in a reducing atmosphere. The conditions of the annealing treatment can also be appropriately adjusted depending on the components of the dielectric layer. For example, the temperature during annealing may be 950°C to 1150°C, the time may be 0 hours to 20 hours, and the temperature increase rate may be 50°C / hour to 500°C / hour. The annealing atmosphere may be humidified nitrogen gas (N 2 ) atmosphere, and the oxygen partial pressure is 1.0×10 -9 MPa~1.0×10 -5 It may be MPa.

[0120] In the binder removal treatment, firing treatment, or annealing treatment, for example, a wetter can be used to moisten the nitrogen gas or mixed gas, and in this case, the water temperature may be 5° C. to 75° C. The binder removal treatment, firing treatment, and annealing treatment may be performed consecutively or independently.

[0121] Optionally, surface treatment such as sandblasting, laser irradiation, barrel polishing, etc. may be performed on the third and fourth faces of the manufactured capacitor body 110. By performing such surface treatment, the ends of the first and second internal electrodes are exposed on the outermost surfaces of the third and fourth faces, which improves the electrical connection between the first and second external electrodes and the first and second internal electrodes, making it easier to form an alloy part.

[0122] Next, an external electrode is formed on one surface of the manufactured capacitor body 110 .

[0123] As an example, a paste for forming a sintered metal layer can be applied to the external electrodes and then sintered to form a sintered metal layer.

[0124] The paste for forming the sintered metal layer may include a conductive metal and glass. The conductive metal and glass have been described above, and therefore will not be described again. The paste for forming the sintered metal layer may selectively include a binder, a solvent, a dispersant, a plasticizer, an oxide powder, and the like. The binder may be, for example, ethyl cellulose, acrylic, butyral, and the solvent may be, for example, an organic solvent or an aqueous solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene.

[0125] The method of applying the sintered metal layer forming paste to the outer surface of the capacitor body 110 can be a dipping method, various printing methods such as screen printing, an application method using a dispenser, a spraying method using a spray, etc. The sintered metal layer forming paste is applied to at least the third and fourth surfaces of the capacitor body 110, and is 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.

[0126] Thereafter, the capacitor body 110 on which the paste for forming a sintered metal layer is applied is dried and sintered at a temperature of 700° C. to 1000° C. for 0.1 to 3 hours to form a sintered metal layer.

[0127] Alternatively, a conductive resin layer forming paste may be applied to the outer surface of the obtained capacitor body 110 and then cured to form a conductive resin layer.

[0128] The paste for forming the conductive resin layer may include a resin, and optionally a conductive metal or a non-conductive filler. The conductive metal and the resin have been described above, and therefore will not be described again. The paste for forming the conductive resin layer may optionally include a binder, a solvent, a dispersant, a plasticizer, an oxide powder, and the like. Examples of the binder include ethyl cellulose, acrylic, butyral, and the like, and examples of the solvent include organic solvents or aqueous solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, and toluene.

[0129] As an 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.

[0130] Next, a plating layer is formed on the outside of the conductive resin layer.

[0131] As an example, the plating layer is formed by a plating method, and may be formed by sputtering or electric deposition.

[0132] The above-mentioned embodiments will be described in more detail with reference to the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the invention.

[0133] (Manufacturing of multilayer ceramic capacitors) Example 1 and Comparative Example 1 Barium titanate (BaTiO 3 ) main component powder, and as subcomponent powder, 1.5 mol parts of magnesium oxide (MgO), dysprosium oxide (Dy 2 O 3 ) 3 mole parts, terbium oxide (Tb 2 O 3 ) 1.5 mole parts, manganese oxide (MnO 2 ) 1 mol part, vanadium oxide (V 2 O 5 ) 1 mol part, aluminum oxide (Al 2 O 3 ) 1 mol part, silicon dioxide (SiO 2 ) 3 molar parts and tin oxide (SnO 2 The content of each subcomponent powder was based on 100 mol parts of the main component powder of barium titanate. The mixing was performed using zirconium balls (ZrO 2 The mixture was mixed with ethanol / toluene, a wetting dispersant, and polyvinyl butyral (PVB) resin as a binder in a dispersion medium of 1000 ml of ethanol / toluene, and then mechanically milled.

[0134] The prepared dielectric slurry was used in a head-discharging on-roll forming coater to prepare a dielectric green sheet.

[0135] A conductive paste layer containing nickel (Ni) was printed on the surface of a dielectric green sheet, and the dielectric green sheets (width x length x height = 3.2 mm x 2.5 mm x 2.5 mm) on which the conductive paste layer was formed were stacked and pressed to produce a dielectric green sheet laminate.

[0136] The manufactured dielectric green sheet laminate was subjected to a plasticization process at 400° C. or less in a nitrogen atmosphere. In the case of Example 1, the firing temperature was 1150° C. to 1250° C. and the hydrogen concentration was 0.8%. 2 Under the following conditions, in the case of Comparative Example 1, the firing temperature was 1100°C to 1140°C and the hydrogen concentration was 0.9%H 2 The firing was carried out under the above conditions.

[0137] Next, a multilayer ceramic capacitor was manufactured through processes such as forming external electrodes and plating.

[0138] Evaluation 1: TEM-EDS analysis The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were subjected to TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) analysis, and the results are shown in FIGS. 5A and 5B.

[0139] The TEM-EDS analysis was performed as follows. The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were placed in an epoxy mixture and cured, and then the L-axis and T-axis faces (LT faces) of the capacitor body were polished to a depth of 1 / 2 in the W-axis direction, and then fixed and maintained in a vacuum atmosphere chamber to obtain a cross-sectional sample so that the active area where the dielectric layers and internal electrode layers intersect could be observed. The side portion of the active area (area A in Figure 2) of the cross-sectional sample was measured using a TEM. The TEM was performed using a Xe-FIB (focused ion beam) at an accelerating voltage of 200 kV and an analysis magnification of 110 kx, so that six dielectric layers and six internal electrode layers could be seen.

[0140] In the TEM image of the measured cross-sectional sample, the presence or absence of Mg-enriched regions in the defects of the internal electrode layers was confirmed by EDS mapping analysis, and the results are shown in FIGS. 5A and 5B.

[0141] FIG. 5A is a TEM-EDS analysis image of an active area of ​​the multilayer ceramic capacitor according to Example 1, and FIG. 5B is a TEM-EDS analysis image of an active area of ​​the multilayer ceramic capacitor according to Comparative Example 1.

[0142] 5A and 5B, in the case of Example 1 according to one embodiment, a Mg-enriched region containing Mg as a main element is formed in the defect portion of the internal electrode layer, that is, in the region where the continuity of the internal electrode layer is interrupted. In addition, it can be seen that Mg element is present in the interface vicinity region in the dielectric layer, which is adjacent to the Mg-enriched region and is located near the interface between the dielectric layer and the internal electrode layer. At this time, it can be seen that the Mg element present in the interface vicinity region in the dielectric layer has a lower concentration, i.e., a lower atomic % content, than the Mg element present in the Mg-enriched region of the defect portion of the internal electrode layer.

[0143] In contrast, in the case of Example 1 and Comparative Example 1 produced under different firing conditions, it can be seen that Mg-enriched regions are not well formed in the defective portions of the internal electrode layers.

[0144] Evaluation 2: EDS-line profile analysis The multilayer ceramic capacitor manufactured in Example 1 was subjected to EDS-line profile analysis, and the results are shown in FIG.

[0145] Specifically, in the TEM image of the cross-sectional sample measured in Evaluation 1, EDS line profile analysis was performed from the internal electrode layer to the dielectric layer to confirm the change in atomic percent concentration of Mg element in the region near the interface between the Mg-enriched region and the dielectric layer, and the results are shown in Figure 6.

[0146] FIG. 6 is a graph showing an EDS line profile analysis of the interface between the dielectric layer and the internal electrode layer of the multilayer ceramic capacitor according to Example 1. As shown in FIG.

[0147] 6, the 0nm to 250nm region where the Mg element concentration converges to 0 is a part having continuity of the internal electrode layer, the 270nm to 400nm region where the Mg element concentration increases corresponds to the vacant portion of the internal electrode layer, and the 400nm to 480nm region where the Mg element concentration decreases corresponds to the interface vicinity region of the dielectric layer. As a result, in the case of Example 1 according to one embodiment, it can be confirmed that there is a Mg enriched region where the Mg element concentration increases in the vacant portion of the internal electrode layer, and it can be seen that the Mg element concentration is relatively decreased in the interface vicinity region of the dielectric layer. From this, it can be seen that the phenomenon that the Mg element in the dielectric is excessively dissolved as an acceptor at the interface between the dielectric layer and the internal electrode layer is suppressed, and thus the potential barrier height is increased.

[0148] Rating 3: Accelerated life reliability The multilayer ceramic capacitors manufactured in Example 1 and Comparative Example 1 were measured for reliability in the following items, and the results are shown in FIGS.

[0149] MTTF (mean time to failure): 40 sample chips were mounted on a reliability board, and then measured at a temperature of 125°C, a voltage of 9.45V, and a test time of 48 hours to determine the mean time to failure (hr).

[0150] FIG. 7 is a graph showing the accelerated life reliability of the multilayer ceramic capacitor according to Example 1, and FIG. 8 is a graph showing the accelerated life reliability of the multilayer ceramic capacitor according to Comparative Example 1.

[0151] 7 and 8, it can be seen that Example 1, in which an Mg-enriched region exists in the defect portion of the internal electrode layer and the Mg element concentration is relatively decreased in the region near the interface of the dielectric layer, has superior accelerated life reliability compared to Comparative Example 1.

[0152] 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 description of the invention, and the accompanying drawings, which of course also fall within the scope of the present invention. [Explanation of symbols]

[0153] 100: Multilayer ceramic capacitor 110: Capacitor body 111: Dielectric layer 121: 1st internal electrode 122:Second internal electrode 131: 1st external electrode 132:Second external electrode A: Active area L: Defective part C: Mg enriched area R: Near-interface region

Claims

1. a capacitor body including a dielectric layer and an internal electrode layer; an external electrode disposed on an outer side of the capacitor body; The internal electrode layer includes at least one defect portion defined by a region where the continuity of the internal electrode layer is interrupted, and the defect portion includes an Mg-enriched region containing magnesium (Mg) as a main element, the dielectric layer includes a near-interface region defined by a region from an interface between the dielectric layer and the internal electrode layer to a depth surface of 80 nm to 100 nm into the dielectric layer, the near-interface region including magnesium (Mg); A multilayer ceramic capacitor, wherein the magnesium (Mg) contained in the interface vicinity region of the dielectric layer has a lower atomic % content than the magnesium (Mg) contained in the Mg-enriched region of the defect portion.

2. 2. The multilayer ceramic capacitor according to claim 1, wherein the magnesium (Mg) contained in the Mg-enriched region of the defect portion is 1.6 atomic % to 11.1 atomic % with respect to the total amount of components in the Mg-enriched region.

3. 2. The multilayer ceramic capacitor according to claim 1, wherein the Mg-enriched region of the defect further contains barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or a combination thereof.

4. The Mg-enriched region of the defect portion contains the titanium (Ti), 4. The multilayer ceramic capacitor according to claim 3, wherein the magnesium (Mg) contained in the Mg enriched region of the defect portion is contained in an amount of 12.68 to 22,000 parts by mole per 100 parts by mole of the titanium (Ti).

5. The Mg-enriched region of the defect portion contains the nickel (Ni), 4. The multilayer ceramic capacitor according to claim 3, wherein the magnesium (Mg) contained in the Mg-enriched region of the defect portion is contained in an amount of 4.75 to 71.58 parts by mol per 100 parts by mol of the nickel (Ni).

6. 2. The multilayer ceramic capacitor according to claim 1, wherein the magnesium (Mg) contained in the Mg-enriched region of the defect portion is contained in a molar ratio of 1.010 to 13.701 relative to the magnesium (Mg) contained in the interface vicinity region of the dielectric layer.

7. 2. The multilayer ceramic capacitor according to claim 1, wherein magnesium (Mg) contained in the Mg-enriched region of the defect portion combines with at least one of nickel (Ni) and oxygen (O) to form a secondary phase.

8. 2. The multilayer ceramic capacitor according to claim 1, wherein the magnesium (Mg) contained in the interface vicinity region of the dielectric layer is 0.8 atomic % to 4.2 atomic % with respect to the total amount of components in the interface vicinity region.

9. 2. The multilayer ceramic capacitor according to claim 1, wherein the interface near-region of the dielectric layer further comprises barium (Ba), titanium (Ti), nickel (Ni), dysprosium (Dy), terbium (Tb), manganese (Mn), vanadium (V), aluminum (Al), silicon (Si), tin (Sn), oxygen (O), or a combination thereof.

10. the interface vicinity region of the dielectric layer contains the titanium (Ti), 10. The multilayer ceramic capacitor according to claim 9, wherein the magnesium (Mg) contained in the interface vicinity region of the dielectric layer is 5.0 to 29.7 parts by mol per 100 parts by mol of the titanium (Ti).

11. A step of preparing a dielectric slurry by mixing a barium titanate-based main component powder and a sub-component powder including a magnesium (Mg)-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 having the conductive paste layers formed thereon to manufacture a dielectric green sheet laminate; sintering the dielectric green sheet laminate to manufacture a capacitor body including dielectric layers and internal electrode layers; and forming an external electrode on one surface of the capacitor body; The internal electrode layer includes at least one defect portion defined by a region where the continuity of the internal electrode layer is interrupted, and the defect portion includes an Mg-enriched region containing magnesium (Mg) as a main element, the dielectric layer includes a near-interface region defined as a region extending from an interface between the dielectric layer and the internal electrode layer to a depth of 80 nm to 100 nm into the dielectric layer, the near-interface region including magnesium (Mg); A method for manufacturing a multilayer ceramic capacitor, wherein the magnesium (Mg) contained in the interface vicinity region of the dielectric layer has a lower atomic % content than the magnesium (Mg) contained in the Mg concentrated region of the defect portion.

12. The method for producing a multilayer ceramic capacitor according to claim 11, wherein the magnesium (Mg)-containing compound is mixed in an amount of 0.01 to 3 parts by mol with respect to 100 parts by mol of the barium titanate-based main component powder.

13. 12. The method for producing a multilayer ceramic capacitor according to claim 11, wherein the auxiliary component powder further comprises a dysprosium (Dy)-containing compound, a terbium (Tb)-containing compound, a manganese (Mn)-containing compound, a vanadium (V)-containing compound, an aluminum (Al)-containing compound, a silicon (Si)-containing compound, a tin (Sn)-containing compound, or a combination thereof.

14. For 100 mol parts of the barium titanate-based main component powder, The dysprosium (Dy)-containing compound is present in an amount of 0.01 to 5 mole parts, The terbium (Tb)-containing compound is present in an amount of 0.01 to 5 mole parts, The manganese (Mn)-containing compound is present in an amount of 0.01 to 5 parts by mole, The vanadium (V)-containing compound is present in an amount of 0.01 to 5 mole parts, The aluminum (Al)-containing compound is present in an amount of 0.01 to 5 parts by mole, The silicon (Si)-containing compound is contained in an amount of 0.01 to 5 parts by mole, The method for producing a multilayer ceramic capacitor according to claim 13, wherein the tin (Sn)-containing compound is contained in an amount of 0.01 to 5 parts by mol.

15. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the conductive paste layer is made of a conductive paste containing nickel (Ni).

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