Multilayered capacitor

Abstract

To provide a multilayered capacitor having excellent electrode connectivity and interfacial bonding force, and further having excellent reliability.SOLUTION: A multilayered capacitor according to an embodiment includes a capacitor body including a dielectric layer 111 and internal electrodes 121 and 122, and external electrodes 131 and 132 disposed outside the capacitor body. The dielectric layer includes a central portion of the dielectric layer and an interface portion located on a surface of the central portion of the dielectric layer. The interface portion of the dielectric layer is in contact with each internal electrode and includes Sn, and the internal electrodes each include a first compound represented by the following chemical formula 1. Mn+1A1-xSnxXn...1. M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof. A includes one or more selected from the group consisting of elements present from Group 11 elements to Group 16 elements. X includes C, N, or a combination thereof. 0<x≤1 is satisfied, and n is an integer of 1 to 4.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a multilayer capacitor.

Background Art

[0002] Recently, with the rapid progress of the multifunctionalization and miniaturization of electronic devices, the miniaturization and performance improvement of electronic components have also been rapidly advanced. In addition, the requirements for the high reliability of electrical devices used in automobiles or network devices, etc., and electronic components for industrial use have also increased significantly.

[0003] In order to meet such market requirements, the technological development competition of passive components such as inductors, capacitors, or resistors has been accelerating. In particular, many efforts are required to take the lead in the market in the development of various products of multilayer ceramic capacitors (MLCCs), which are passive components with continuously increasing applications and usage amounts.

[0004] In addition, a multilayer capacitor is a capacitor manufactured in a form in which dielectric layers and internal electrodes are stacked, and is used in various electronic devices such as mobile phones, notebook computers, and LCD (liquid crystal) TVs.

[0005] Recently, with the development of technology, multilayer capacitors have been required to be miniaturized and have a higher capacitance. For this purpose, technology development has been carried out to enhance the connectivity of the internal electrodes in contact with the dielectric layers to increase the effective electrode area, or to make the dielectric material and the internal electrode material finer.

[0006] However, when the above materials are made finer, the melting point decreases, and the thermal shrinkage start temperature of the materials may decrease. In particular, in the case of the metal materials contained in the internal electrodes, since the rate of decrease in the thermal shrinkage start temperature is higher than that of the ceramic materials contained in the dielectric layers, the thermal shrinkage temperature difference between the dielectric layers and the internal electrodes becomes larger.

[0007] The greater the difference in the thermal contraction temperature between the dielectric layer and the internal electrode, the greater the likelihood that the electrode connectivity will decrease after firing the dielectric layer and the internal electrode, and the electrical capacitance and reliability of the multilayer capacitor will deteriorate.

[0008] Currently, in order to reduce the difference in the thermal contraction temperature between the dielectric layer and the internal electrode, a method of adding a nano-sized barium titanate (BaTiO3) co-material during the manufacture of the internal electrode is used.

[0009] However, when the content of the barium titanate co-material increases, the film density of the internal electrode decreases, and a side effect occurs in which the co-material diffused into the dielectric layer during the firing process increases the thickness of the dielectric layer and decreases the capacitance of the capacitor.

Summary of the Invention

Problems to be Solved by the Invention

[0010] One embodiment of the present invention provides a multilayer capacitor having excellent electrode connectivity and interfacial bonding strength and excellent reliability.

[0011] However, the problems to be solved by the embodiments are not limited to the above-described problems, and can be variously extended within the scope of the technical idea included in the embodiments.

Means for Solving the Problems

[0012] A multilayer capacitor according to one embodiment of the present invention includes a capacitor body including a dielectric layer and an internal electrode, and an external electrode disposed outside the capacitor body. The dielectric layer includes a central portion of the dielectric layer and an interfacial portion located on the surface of the central portion of the dielectric layer, and the interfacial portion of the dielectric layer is in contact with the internal electrode. The interfacial portion of the dielectric layer contains Sn. The internal electrode contains a first compound represented by the following Chemical Formula 1.

[0013] [Chemical Formula 1] M n+1 A 1-x Snx X n In the formula (1), M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements, X includes C, N, or a combination thereof, 0 < x ≤ 1, and n is an integer from 1 to 4.

[0014] The M may include Ti, Zr, Hf, Nb, or a combination thereof.

[0015] The first compound may include Ti2SnC, Zr2SnC, Nb2SnC, Hf2SnC, Hf2SnN, Ti3SnC2, or a combination thereof.

[0016] The content of Sn at the interface of the dielectric layer may be 0.1 at% to 0.5 at%.

[0017] The internal electrode includes a central portion of the internal electrode and an interface portion located on the surface of the central portion of the internal electrode, and the interface portion of the internal electrode is in contact with the dielectric layer. The central portion of the internal electrode may include the first compound and a third compound represented by the following Chemical Formula 3.

[0018] [Chemical Formula 3] M n+1 X n In the formula (3), M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, X includes C, N, or a combination thereof, n is an integer from 1 to 4.

[0019] The interface portion of the internal electrode may include Sn and the third compound.

[0020] The third compound may include Ti2C, Zr2C, Nb2C, Hf2C, Hf2N, Ti3C2, or a combination thereof.

[0021] The content of Sn at the interface of the internal electrode may be 0.01 at% to 0.3 at%.

[0022] The central part and the interface part of the dielectric layer contain a main component and a sub-component. The main component is Ba m TiO3 (0.995 ≤ m ≤ 1.010), (Ba 1-X Ca x ) m (Ti 1-y Zr y )O3 (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), Ba m (Ti 1-x Zr x )O3 (0.995 ≤ m ≤ 1.010, x ≤ 0.10), (Ba 1-X Ca x ) m (Ti 1-y Sn y )O3 (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), or a combination thereof.

[0023] The sub-component may include dysprosium (Dy), manganese (Mn), vanadium (V), silicon (Si), aluminum (Al), barium (Ba), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), lanthanum (La), chromium (Cr), hafnium (Hf), yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof.

[0024] A multilayer capacitor according to another embodiment includes a capacitor body including a dielectric layer and internal electrodes, and external electrodes disposed outside the capacitor body. The dielectric layer includes a central portion of the dielectric layer and an interface portion located on the surface of the central portion of the dielectric layer. The interface portion of the dielectric layer is in contact with the internal electrodes. The interface portion of the dielectric layer contains Sn. The internal electrodes contain a second compound represented by Chemical Formula 2 below and Sn.

[0025] [Chemical Formula 2] M n+1 AX n In Chemical Formula 2 above, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof. A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements. X includes C, N, or a combination thereof. n is an integer from 1 to 4.

[0026] The second compound can include Ti2CdC, Sc2InC, Sc2SnC, Ti2AlC, Ti2GaC, Ti2InC, Ti2TlC, V2AlC, V2GaC, Cr2GaC, Ti2AlN, Ti2GaN, Ti2InN, V2GaN, Cr2GaN, Ti2GeC, Ti2SnC, Ti2PbC, V2GeC, Cr2AlC, Cr2GeC, V2PC, V2AsC, Ti2SC, Zr2InC, Zr2TlC, Nb2AlC, Nb2GaC, Nb2InC, Mo2GaC, Zr2InN, Zr2TlN, Zr2SnC, Zr2PbC, Nb2SnC, Nb2PC, Nb2AsC, Zr2SC, Nb2SC, Hf2InC, Hf2TlC, Ta2AlC, Ta2GaC, Hf2SnC, Hf2PbC, Hf2SnN, Hf2SC, Zr2AlC, Ti2ZnC, Ti2ZnN, V2ZnC, Nb2CuC, Mn2GaC, Mo2AuC, Ti2AuN, Ti3AlC2, Ti3GaC2, Ti3InC2, V3AlC2, Ti3SiC2, Ti3GeC2, Ti3SnC2, Ta3AlC2, Ti3ZnC2, Zr3AlC2, Ti4AlN3, V4AlC3, Ti4GaC3, Ti4SiC3, Ti4GeC3, Nb4AlC3, Ta4AlC3, (Mo,V)4AlC3, Mo4VAlC4, or a combination thereof.

[0027] The content of Sn at the interface of the dielectric layer can be 0.1 at% to 0.5 at%.

[0028] The internal electrode includes a central portion of the internal electrode and an interface portion located on the surface of the central portion of the internal electrode, and the interface portion of the internal electrode is in contact with the dielectric layer. The central portion of the internal electrode can include the second compound and a third compound represented by the following Chemical Formula 3.

[0029] [Chemical Formula 3] M n+1 X n In Chemical Formula 3, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof. X contains C, N, or a combination thereof, n is an integer from 1 to 4.

[0030] The interface portion of the internal electrode can contain Sn and the third compound.

[0031] The third compound can contain Ti2C, Zr2C, Nb2C, Hf2C, Hf2N, Ti3C2, or a combination thereof.

[0032] The content of Sn in the interface portion of the internal electrode can be from 0.01 at% to 0.3 at%.

[0033] The central portion and the interface portion of the dielectric layer contain a main component and a sub-component, The main component is Ba m TiO3 (0.995 ≦ m ≦ 1.010), (Ba 1-X Ca x ) m (Ti 1-y Zr y )O3 (0.995 ≦ m ≦ 1.010, 0 ≦ x ≦ 0.10, 0 < y ≦ 0.20), Ba m (Ti 1-x Zr x )O3 (0.995 ≦ m ≦ 1.010, x ≦ 0.10), (Ba 1-X Ca x ) m (Ti 1-y Sn y )O3 (0.995 ≦ m ≦ 1.010, 0 ≦ x ≦ 0.10, 0 < y ≦ 0.20), or a combination thereof.

[0034] The sub-components may include dysprosium (Dy), manganese (Mn), vanadium (V), silicon (Si), aluminum (Al), barium (Ba), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), lanthanum (La), chromium (Cr), hafnium (Hf), yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or combinations thereof.

Advantages of the Invention

[0035] According to the multilayer capacitor according to the embodiment of the present invention, it has advantages of excellent electrode connectivity and interfacial bonding strength, and excellent reliability.

[0036] However, the various and beneficial advantages and effects of the present invention are not limited to the above-described content, and should be more easily understood in the process of describing the specific embodiments of the present invention.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0038] Hereinafter, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it with reference to the attached drawings. In order to clearly explain the present invention in the drawings, parts unnecessary for the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification. Also, the attached drawings are only for facilitating the understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and it must be understood that all modifications, equivalents, or alternatives included in the idea and technical scope of the present invention are included.

[0039] Terms including ordinal numbers such as first and second can be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

[0040] When a certain component is referred to as being "connected to" or "attached to" another component, it should be understood that it may be directly connected to, attached to, or facing the other component, but there may also be other components in between. On the contrary, when a certain component is referred to as being "directly connected to" or "directly attached to" another component, it should be understood that there are no other components in between.

[0041] Throughout the specification, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be construed as precluding 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 component, this means that it can further comprise other components rather than excluding other components unless there is a contrary description.

[0042] FIG. 1 is a perspective view showing a multilayer capacitor 100 according to an embodiment, FIG. 2 is a cross-sectional view of the multilayer capacitor 100 cut along the line I-I' of FIG. 1, and FIG. 3 is an exploded perspective view showing the laminated structure of the internal electrodes in the capacitor body 110 of FIG. 1.

[0043] To clearly explain this embodiment, if directions are defined, the L-axis, W-axis, and T-axis shown in the drawings indicate the length direction, width direction, and thickness direction of the capacitor body 110, respectively. Here, the thickness direction (T-axis direction) may be a direction perpendicular to the broad surface (main surface) of the sheet-shaped component, and as an example, it can be used as the same concept as the lamination direction in which the dielectric layer 111 is laminated. The length direction (L-axis direction) may be a direction extending parallel to the broad surface (main surface) of the sheet-shaped component and substantially perpendicular to the thickness direction (T-axis direction), and as an example, it may be the 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 broad 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), and the length of the sheet-shaped component in the length direction (L-axis direction) may be longer than the length in the width direction (W-axis direction).

[0044] Referring to FIGS. 1 to 3, a multilayer capacitor 100 according to an embodiment may include a capacitor body 110, and a first external electrode 131 and a second external electrode 132 disposed at both ends facing the length direction (L-axis direction) of the capacitor body 110.

[0045] The capacitor body 110 may be, for example, in a roughly hexahedral shape.

[0046] In this embodiment, for convenience of explanation, both surfaces of the capacitor body 110 facing each other in the thickness direction (T-axis direction) are defined as the first surface and the second surface, both surfaces connected to the first surface and the second surface and facing each other in the length direction (L-axis direction) are defined as the third surface and the fourth surface, and both surfaces connected to the first surface and the second surface and connected to the third surface and the fourth surface and facing each other in the width direction (W-axis direction) are defined as the fifth surface and the sixth surface.

[0047] As an example, the first surface, which is the lower surface, can be the surface facing the mounting direction. Also, the first surface to the sixth surface may be flat, but this embodiment is not limited thereto. For example, the first surface to the sixth surface may be a curved surface convex at the center, and the corners that are the boundaries of each surface may be rounded.

[0048] The shape, dimensions, and the number of stacked dielectric layers 111 of the capacitor body 110 are not limited to those shown in the drawings of this embodiment.

[0049] The capacitor body 110 is formed by stacking a plurality of dielectric layers 111 in the thickness direction (T-axis direction) and then firing, and includes a first internal electrode layer 121 and a second internal electrode layer 122 that are alternately arranged in the thickness direction (T-axis direction) with the plurality of dielectric layers 111 interposed therebetween.

[0050] At this time, the boundaries between the respective adjacent dielectric layers 111 of the capacitor body 110 can be integrated to such an extent that it is difficult to confirm without using a scanning electron microscope (SEM).

[0051] In addition, the capacitor body 110 can include an active region and cover regions 112 and 113.

[0052] The active region is a portion that contributes to the capacitance formation of the stacked capacitor 100. As an example, 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.

[0053] The cover regions 112 and 113 are margin portions in the thickness direction and can be respectively disposed on the first and second surface sides of the active region in the thickness direction (T-axis direction). Such cover regions 112 and 113 may be a single dielectric layer 111 or two or more dielectric layers 111 respectively stacked on the upper and lower surfaces of the active region.

[0054] In addition, the capacitor body 110 can further include a side cover region. The side cover region is a margin portion in the width direction and can be respectively disposed on the fifth and sixth surface sides of the active region in the width direction (W-axis direction). Such a side cover region can be formed by applying a conductive paste layer for internal electrode formation only to a partial region of the surface of the dielectric green sheet when applying the conductive paste layer to the surface of the dielectric green sheet, stacking dielectric green sheets without applying the conductive paste layer to both side surfaces of the surface of the dielectric green sheet, and then firing.

[0055] The cover regions 112 and 113 and the side cover region serve to prevent damage to the first internal electrode layer 121 and the second internal electrode layer 122 due to physical or chemical stress.

[0056] Internal electrode The first internal electrode 121 and the second internal electrode 122 are electrodes having different polarities from each other, and are alternately arranged so as to face each other along the T-axis direction with the dielectric layer 111 interposed therebetween, and one end of each is exposed through the third and fourth surfaces of the capacitor body 110.

[0057] 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.

[0058] The ends of the first internal electrode 121 and the second internal electrode 122 that are alternately exposed through the third and fourth surfaces of the capacitor body 110 can be connected to the first external electrode 131 and the second external electrode 132, respectively, and electrically connected.

[0059] In one embodiment, the internal electrodes 121, 122 contain a first compound represented by the following Chemical Formula 1.

[0060] [Chemical Formula 1] M n+1 A 1-x Sn x X n In Chemical Formula 1, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements, X includes C, N, or a combination thereof, 0 < x ≦ 1, and n is an integer from 1 to 4.

[0061] As an example, M can include Ti, Zr, Hf, Nb, or a combination thereof.

[0062] As an example, A can include any one or more selected from the group consisting of Group 11 elements to Group 16 elements. As an example, A can include Group 13 elements, Group 14 elements, and combinations thereof. As a specific example, A can include Al, Ga, In, Tl, Si, Ge, Sn, Pb, Zn, Cd, P, As, S, Cu, Au, or a combination thereof.

[0063] As a specific example, the first compound can include Ti2SnC, Zr2SnC, Nb2SnC, Hf2SnC, Hf2SnN, Ti3SnC2, or a combination thereof.

[0064] The first compound may be a MAX phases compound containing Sn.

[0065] The MAX phase compound is a compound having all the characteristics of metals and ceramics, and is characterized by very excellent thermal conductivity and electrical conductivity, high strength and modulus.

[0066] As an example, since the sintering temperature of the MAX phase compound is higher than that of metals such as Ni, the difference in sintering temperature between the dielectric material of the dielectric layer 111 and the MAX phase compound may not be large. Thus, when the internal electrodes 121, 122 containing the MAX phase compound and the dielectric layer 111 are fired together, no mismatching problem occurs between the dielectric layer 111 and the internal electrodes 121, 122, so that breaks in the internal electrodes 121, 122 and thickness expansion can be prevented, and electrode connectivity can be significantly improved.

[0067] As an example, when the conductive paste for forming the internal electrode layer containing the first compound is applied to the dielectric green sheet and fired simultaneously, a part of Sn in the first compound decomposes and can diffuse to the interface between the dielectric layer 111 and the internal electrodes 121, 122.

[0068] As an example, the first compound can form a joint at the interface between the dielectric layer 111 and the internal electrodes 121, 122 by transient liquid diffusion bonding during the firing process.

[0069] As a specific example, during the firing process of the first compound, Sn decomposes and Sn temporarily exists in a liquid form at the interface between the dielectric layer 111 and the internal electrodes 121, 122, and the formed liquid substance can solidify isothermally while bonding the dielectric layer 111 and the internal electrodes 121, 122.

[0070] In another embodiment, the internal electrodes 121 and 122 contain a second compound represented by Chemical Formula 2 below and Sn.

[0071] [Chemical Formula 2] M n+1 AX n In Chemical Formula 2 above, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof; A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements; X includes C, N, or a combination thereof; and n is an integer from 1 to 4.

[0072] As an example, A can include Group 13 elements, Group 14 elements, and combinations thereof. As a specific example, A can include Al, Ga, In, Tl, Si, Ge, Sn, Pb, Zn, Cd, P, As, S, Cu, Au, or combinations thereof.

[0073] As an example, the second compound can include Ti2CdC, Sc2InC, Sc2SnC, Ti2AlC, Ti2GaC, Ti2InC, Ti2TlC, V2AlC, V2GaC, Cr2GaC, Ti2AlN, Ti2GaN, Ti2InN, V2GaN, Cr2GaN, Ti2GeC, Ti2SnC, Ti2PbC, V2GeC, Cr2AlC, Cr2GeC, V2PC, V2AsC, Ti2SC, Zr2InC, Zr2TlC, Nb2AlC, Nb2GaC, Nb2InC, Mo2GaC, Zr2InN, Zr2TlN, Zr2SnC, Zr2PbC, Nb2SnC, Nb2PC, Nb2AsC, Zr2SC, Nb2SC, Hf2InC, Hf2TlC, Ta2AlC, Ta2GaC, Hf2SnC, Hf2PbC, Hf2SnN, Hf2SC, Zr2AlC, Ti2ZnC, Ti2ZnN, V2ZnC, Nb2CuC, Mn2GaC, Mo2AuC, Ti2AuN, Ti3AlC2, Ti3GaC2, Ti3InC2, V3AlC2, Ti3SiC2, Ti3GeC2, Ti3SnC2, Ta3AlC2, Ti3ZnC2, Zr3AlC2, Ti4AlN3, V4AlC3, Ti4GaC3, Ti4SiC3, Ti4GeC3, Nb4AlC3, Ta4AlC3, (Mo,V)4AlC3, Mo4VAlC4, or combinations thereof.

[0074] The second compound is classified into the above-described first compound and can be a general MAX phases compound in which A may or may not contain Sn.

[0075] When the conductive paste for forming the internal electrode layer containing the second compound and Sn is applied to the dielectric green sheet and fired simultaneously, the Sn can diffuse to the interface between the dielectric layer 111 and the internal electrodes 121 and 122.

[0076] As an example, in the process of firing the second compound and Sn, Sn diffuses to the interface between the dielectric layer 111 and the internal electrodes 121 and 122 and exists in a liquid form, and the formed liquid substance can join the dielectric layer 111 and the internal electrodes 121 and 122 while solidifying isothermally.

[0077] When joining the dielectric layer 111 and the internal electrodes 121 and 122 by the method described above, the interfacial bonding force is improved by the liquid substance formed at the interface, enabling the two layers to be easily joined, and the mechanical properties of the joint are excellent.

[0078] In addition, a joint having physicochemical properties similar to those of the substances contained in the dielectric layer 111 and the internal electrodes 121 and 122 is formed, and peeling and cracking of the interface can be suppressed by reducing the difference in thermal shrinkage temperature between the internal electrodes 121 and 122 and the dielectric layer 111.

[0079] As a result, since the interfacial bonding force between the internal electrodes 121 and 122 and the dielectric layer 111 is excellent, stable capacitor characteristics (such as reliability and electrical characteristics) can be realized.

[0080] Figure 4 is a scanning electron microscope (SEM) image of a part of the cross-section of a multilayer capacitor according to an embodiment. The SEM image of the cross-section of the multilayer capacitor can be prepared by the following method.

[0081] First, after placing the multilayer capacitor 100 in an epoxy mixture and curing it, the sides of the capacitor body 110 in the L-axis direction and the T-axis direction are polished to the 1 / 2 point in the W-axis direction, fixed, and maintained in a vacuum atmosphere chamber, and a cross-section sample (hereinafter referred to as "cross-section sample") cut from the center of the capacitor body 110 in the W-axis direction in the L-axis direction and the T-axis direction is prepared. Then, the cross-section sample is observed with a scanning electron microscope (SEM) to prepare an SEM image.

[0082] Referring to Figure 4, by differentiating the bright and dark parts by methods such as binarizing the SEM image of the cross-section sample, the central parts of the internal electrodes 121 and 122 and the interface parts of the internal electrodes 121 and 122 can be confirmed.

[0083] Referring to FIG. 4, the internal electrodes 121 and 122 can include the interface portions of the internal electrodes 121 and 122 that are located at the central portions of the internal electrodes 121 and 122 and on the surfaces of the central portions of the internal electrodes 121 and 122 and are in contact with the dielectric layer 111.

[0084] The central portions of the internal electrodes 121 and 122 can mean the intermediate point between a point on one side surface of any one of the internal electrodes and a point on the other side surface of the internal electrode that is located at the shortest distance from the point in the cross-section obtained by cutting the capacitor body 110 in the L-axis direction and the T-axis direction from the center in the W-axis direction. Also, it can mean not only the intermediate point but also the region within ±30% in the T-axis direction with respect to the intermediate point.

[0085] The interface portions of the internal electrodes 121 and 122 can mean the point that is 5 μm separated in the T-axis direction from the interface disposed between the dielectric layer 111 and the internal electrodes 121 and 122 toward the central portions of the internal electrodes 121 and 122 in a region other than the central portions of the internal electrodes 121 and 122.

[0086] As an example, the interface portions of the internal electrodes 121 and 122 can mean the points from 1 / 4 to 1 / 2 of the thickness of the internal electrode in the T-axis direction from the interface disposed between the dielectric layer 111 and the internal electrodes 121 and 122 toward the central portions of the internal electrodes 121 and 122.

[0087] Also, it can mean not only the said point but also the region within ±30% in the T-axis direction with respect to the point.

[0088] As an example, the central portions of the internal electrodes 121 and 122 can include the first compound and the third compound represented by the following Chemical Formula 3.

[0089] As another example, the central portions of the internal electrodes 121 and 122 can include the second compound and the third compound represented by the following Chemical Formula 3.

[0090] As an example, the interface portion of the internal electrodes 121 and 122 can contain Sn and a third compound represented by the following Chemical Formula 3.

[0091] [Chemical Formula 3] M n+1 X n In Chemical Formula 3, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, X includes C, N, or a combination thereof, and n is an integer from 1 to 4.

[0092] As an example, M can include Ti, Zr, Hf, Nb, or a combination thereof.

[0093] As a specific example, the third compound can include Ti2C, Zr2C, Nb2C, Hf2C, Hf2N, Ti3C2, or a combination thereof.

[0094] The third compound can be a compound after Sn has decomposed and escaped from the first compound described above, or a compound after A has decomposed and escaped from the second compound described above.

[0095] As an example, when the conductive paste for forming the internal electrode layer containing the first compound is fired, Sn contained in the first compound may decompose and exist at the interface portion of the internal electrodes 121 and 122, and the third compound, which is the compound after Sn has decomposed and escaped, may be contained in the central portion of the internal electrodes 121 and 122, the interface portion of the internal electrodes 121 and 122, or both.

[0096] As another example, when the conductive paste for forming the internal electrode layer containing the second compound and Sn is fired, Sn may diffuse and exist at the interface portion of the internal electrodes 121 and 122, and the third compound, which is the compound after A has decomposed and escaped from the second compound, may be contained in the central portion of the internal electrodes 121 and 122, the interface portion of the internal electrodes 121 and 122, or both.

[0097] FIG. 5 is a graph showing the elemental content (atomic %) by SEM-EDS analysis at the position shown in FIG. 4, where (a) and (b) show the elemental content at the center of the internal electrode, and (c) shows the elemental content at the interface of the internal electrode.

[0098] As an example, the content of Sn (atomic %; at%) at the interface of the internal electrodes 121 and 122 may be 0.01 at% or more, 0.05 at% or more, or 0.1 at% or more, and may be 0.3 at% or less, 0.2 at% or less, or 0.15 at% or less. When the above numerical range is satisfied, a laminated capacitor with excellent electrode connectivity and interfacial bonding strength can be realized.

[0099] As an example, the internal electrodes 121 and 122 may further contain a conductive metal, and the conductive metal may further contain, for example, metals such as Ni, Cu, Ag, Pd, or Au, or alloys thereof, such as an Ag-Pd alloy.

[0100] Also, the first internal electrode 121 and the second internal electrode 122 may contain dielectric particles of the same composition system as the ceramic material contained in the dielectric layer 111.

[0101] The first internal electrode 121 and the second internal electrode 122 can be formed using a conductive paste containing a conductive metal. As the printing method of the conductive paste, a screen printing method or a gravure printing method can be used.

[0102] As an example, the average thickness of the first internal electrode 121 and the second internal electrode 122 may be 0.05 μm or more, 0.1 μm or more, 0.2 μm or more, or 0.25 μm or more, and may be 10 μm or less, 5 μm or less, or 1 μm or less.

[0103] The average thickness of the first internal electrodes 121 and 122 can be measured by the following method.

[0104] In the scanning electron microscope (SEM) image of the cross-sectional sample, taking the central point in the L-axis direction or the W-axis direction of the first internal electrode 121 or the second internal electrode 122 as a reference point, the arithmetic mean value of the thicknesses of the internal electrodes 121 and 122 at 10 points separated from the reference point by a predetermined interval can be obtained, and the average thickness of the internal electrode can be obtained.

[0105] 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, an interval of 1 μm to 100 μm, 1 μm to 50 μm, or 1 μm to 10 μm.

[0106] At this time, all 10 points must be located within the first internal electrode 121 or the second internal electrode 122. 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.

[0107] Dielectric layer When manufacturing a multilayer capacitor according to an embodiment, when the conductive paste for forming an internal electrode layer containing the first compound is applied to a dielectric green sheet and fired, Sn can be decomposed by the first compound and diffuse into the dielectric layer 111.

[0108] When manufacturing a multilayer capacitor according to another embodiment, when the conductive paste for forming an internal electrode layer containing the second compound and Sn is applied to a dielectric green sheet and fired, the Sn can diffuse into the dielectric layer 111.

[0109] The diffused Sn may be present at the interface between the dielectric layer 111 and the internal electrodes 121 and 122, thereby realizing a multilayer capacitor with excellent interfacial bonding force between the dielectric layer 111 and the internal electrodes 121 and 122.

[0110] Referring to FIG. 4, in a stacked capacitor according to an embodiment, the dielectric layer 111 is located at the center of the dielectric layer 111 and on the surface of the center of the dielectric layer 111, and includes the interface portion of the dielectric layer 111 that contacts the internal electrodes 121 and 122.

[0111] The central portion of the dielectric layer 111 can mean the intermediate point between one point on one side surface of any one dielectric layer and one point on the other side surface of the dielectric layer located at the shortest distance from the point in the cross-section obtained by cutting in the L-axis direction and the T-axis direction from the center in the W-axis direction of the capacitor body 110. Also, it can mean not only the intermediate point but also the region within ±30% in the T-axis direction based on the intermediate point.

[0112] The interface portion of the dielectric layer 111 can mean a point 5 μm away in the T-axis direction from the interface disposed between the dielectric layer 111 and the internal electrodes 121 and 122 toward the central portion of the dielectric layer 111 in a region other than the central portion of the dielectric layer 111.

[0113] As an example, the interface portion of the dielectric layer 111 can mean a point from 1 / 4 to 1 / 2 of the thickness of the dielectric layer in the T-axis direction from the interface disposed between the dielectric layer 111 and the internal electrodes 121 and 122 toward the central portion of the dielectric layer 111.

[0114] Also, it can mean not only the point but also the region within ±30% in the T-axis direction based on the point.

[0115] FIG. 5 is a graph showing the element content (atomic %) by SEM-EDS analysis at the position shown in FIG. 4, where (d) shows the element content at the interface portion of the dielectric layer and (e) shows the element content at the central portion of the dielectric layer.

[0116] Referring to FIGS. 4 and 5, the interface portion of the dielectric layer 111 contains Sn.

[0117] As an example, the dielectric layer 111 including the central portion of the dielectric layer 111 and the interface portion of the dielectric layer 111 contains a dielectric, and the dielectric can include a main component and a sub-component.

[0118] The main component is the base material of the dielectric, has a high dielectric constant, and contributes to the formation of the dielectric constant of the multilayer capacitor 100.

[0119] As an example, the main component may be a barium titanate-based compound, for example, Ba m TiO3 (0.995 ≤ m ≤ 1.010), (Ba 1-X Ca x ) m (Ti 1-y Zr y )O3 (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), Ba m (Ti 1-x Zr x )O3 (0.995 ≤ m ≤ 1.010, x ≤ 0.10), (Ba 1-X Ca x ) m (Ti 1-y Sn y )O3 (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), or a dielectric material containing a combination thereof may be used.

[0120] As an example, the main component can include BaTiO3, Ba(Ti,Zr)O3, Ba(Ti,Sn)O3, (Ba,Ca)TiO3, (Ba,Ca)(Ti,Zr)O3, (Ba,Ca)(Ti,Sn)O3, (Ba,Sr)TiO3, (Ba,Sr)(Ti,Zr)O3, (Ba,Sr)(Ti,Sn)O3, or a combination thereof.

[0121] As an example, the sub-component may include dysprosium (Dy), manganese (Mn), vanadium (V), silicon (Si), aluminum (Al), barium (Ba), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), lanthanum (La), chromium (Cr), hafnium (Hf), yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof.

[0122] The dielectric layer 111 may further include a ceramic additive, an organic solvent, a binder, a dispersant, or a combination thereof.

[0123] As an example, the content of Sn (at%) at the interface of the dielectric layer 111 may be 0.1 at% or more, 0.15 at% or more, or 0.2 at% or more, and may be 0.5 at% or less, 0.4 at% or less, or 0.3 at% or less. When the above numerical range is satisfied, a laminated capacitor excellent in electrode connectivity and interface bonding strength can be realized.

[0124] As an example, the average thickness of the dielectric layer 111 may be 0.05 μm or more, 0.1 μm or more, or 0.2 μm or more, and may be 10 μm or less, 5 μm or less, or 1 μm or less.

[0125] The average thickness of the dielectric layer 111 can be measured by the following method.

[0126] First, prepare a scanning electron microscope image obtained by observing a cross-sectional sample with a scanning electron microscope (SEM).

[0127] In the scanning electron microscope (SEM) image of the cross-sectional sample, taking the central point in the L-axis direction or the W-axis direction of the dielectric layer 111 as the reference point, the arithmetic mean value of the thickness of the dielectric layer 111 at 10 points separated from the reference point by a predetermined interval can be obtained and used as the average thickness of the dielectric layer 111.

[0128] The interval between the 10 points can be adjusted according to the scale of the scanning electron microscope (SEM) image, and can be, for example, an interval of 1 μm to 100 μm, 1 μm to 50 μm, or 1 μm to 10 μm.

[0129] At this time, all 10 points must be located within the dielectric layer 111. If all 10 points are not located within the dielectric layer 111, the position of the reference point can be changed, or the interval between the 10 points can be adjusted.

[0130] External electrode The first external electrode 131 and the second external electrode 132 are provided with voltages of different polarities and are respectively connected to the exposed portions of the first internal electrode 121 and the second internal electrode 122 and can be electrically connected.

[0131] 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 first internal electrode 121 and the second internal electrode 122 facing each other. At this time, the capacitance of the multilayer capacitor 100 is proportional to the overlapping 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.

[0132] The first external electrode 131 and the second external electrode 132 are respectively disposed on the third surface and the fourth surface of the capacitor body 110, and include a first connection portion and a second connection portion connected to the first internal electrode 121 and the second internal electrode 122, the third surface and the fourth surface of the capacitor body 110, and a first band portion and a second band portion disposed at the corners where the first surface and the second surface or the fifth surface and the sixth surface are in contact.

[0133] The first band portion and the second band portion are each extended from the first connection portion and the second connection portion to a part of the first surface and the second surface or the fifth surface and the sixth surface of the capacitor body 110. The first band portion and the second band portion serve to improve the adhesion strength of the first external electrode 131 and the second external electrode 132.

[0134] As an example, each of the first external electrode 131 and the second external electrode 132 may include a sintered metal layer that contacts 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.

[0135] The sintered metal layer may include a conductive metal and glass.

[0136] As an example, the sintered metal layer 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 as the conductive metal. For example, copper (Cu) may include a copper (Cu) alloy. When the conductive metal includes copper, the metal other than copper may be included in an amount of 5 mol parts or less with respect to 100 mol parts of copper.

[0137] As an example, the sintered metal layer may include a composition in which an oxide is mixed as glass. For example, it may be 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 is selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni), the alkali metal is 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).

[0138] Optionally, the conductive resin layer is formed on the sintered metal layer, and for example, it can be formed in a form that completely covers the sintered metal layer. On the other hand, the first external electrode 131 and the second external electrode 132 may not include the sintered metal layer. In this case, the conductive resin layer may be in direct contact with the capacitor body 110.

[0139] The conductive resin layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. The length of the region (i.e., the band portion) where the conductive resin layer extends and is disposed on the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 may be longer than the length of the region (i.e., the band portion) where the sintered metal layer extends and is disposed on the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. That is, the conductive resin layer can be formed on the sintered metal layer and can be formed in a form that completely covers the sintered metal layer.

[0140] The conductive resin layer contains resin and conductive metal.

[0141] The resin contained in the conductive resin layer has bonding properties and shock absorption properties, and is not particularly limited as long as it can be mixed with the conductive metal powder to make a paste. For example, it can include phenolic resin, acrylic resin, silicone resin, epoxy resin, or polyimide resin.

[0142] The conductive metal contained in the conductive resin layer serves to be electrically connected to the first internal electrode 121 and the second internal electrode 122 or the sintered metal layer.

[0143] The conductive metal contained in the conductive resin layer can have a spherical shape, a flake shape, or a combination of these forms. That is, the conductive metal may consist only of the flake shape, or only of the spherical shape, or may be a form in which the flake shape and the spherical shape are mixed.

[0144] Here, the spherical shape can include forms that are not completely spherical. For example, it can include forms where the length 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 form, and is not particularly limited. For example, the length ratio of the major axis to the minor axis (major axis / minor axis) may be 1.95 or more.

[0145] The first external electrode 131 and the second external electrode 132 can further include a plating layer disposed outside the conductive resin layer.

[0146] The plating layer can include nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), etc. alone or alloys thereof. As an example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or may be a form in which a nickel (Ni) plating layer and a tin (Sn) plating layer are sequentially laminated, or may be a form in which a tin (Sn) plating layer, a nickel (Ni) plating layer, and a tin (Sn) plating layer are sequentially laminated. Also, the plating layer can include a plurality of nickel (Ni) plating layers and / or a plurality of tin (Sn) plating layers.

[0147] The plating layer can improve the mountability with the substrate of the multilayer capacitor 100, the structural reliability, the durability against the outside, the heat resistance, and the equivalent series resistance (ESR).

[0148] Manufacturing method of multilayer capacitor The manufacturing method of the multilayer capacitor according to another embodiment includes a step of manufacturing a capacitor body including a dielectric layer and an internal electrode, and a step of forming an external electrode outside the capacitor body.

[0149] First, the manufacturing of the capacitor body will be described.

[0150] In the manufacturing process of the capacitor body, a dielectric paste that becomes a dielectric layer after firing and a conductive paste that becomes an internal electrode after firing are prepared.

[0151] The dielectric paste is manufactured, for example, by the following method. Dielectric powder is uniformly mixed by means such as wet mixing, dried, and then heat-treated under predetermined conditions to obtain plastic powder. An organic vehicle or an aqueous vehicle is added to the obtained plastic powder and kneaded to prepare a dielectric paste.

[0152] The obtained dielectric paste is formed into a sheet by a technique such as the doctor blade method to obtain a dielectric green sheet. Further, the dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, sub-component compounds, or glass as necessary.

[0153] In one embodiment, the conductive paste for the internal electrode is prepared by kneading the above-described first compound with a binder and a solvent.

[0154] In another embodiment, the conductive paste for the internal electrode is prepared by kneading the above-described second compound and Sn with a binder and a solvent. In this case, the Sn can be contained at 1 wt% or more or 5 wt% or more with respect to 100 wt% of the conductive paste for the internal electrode, and can be contained at less than 20 wt%, 15 wt% or less, or 10 wt% or less.

[0155] Since the first compound and the second compound are as described above, detailed description thereof is omitted here.

[0156] On the surface of the dielectric green sheet, a conductive paste for internal electrodes is applied in a predetermined pattern by various printing methods such as screen printing or transfer methods. Then, after laminating the dielectric green sheets with internal electrode patterns over a plurality of layers, a dielectric green sheet laminate is obtained by pressing in the lamination direction. At this time, the dielectric green sheet and the internal electrode pattern can be laminated so that the dielectric green sheets are positioned on the upper and lower surfaces in the lamination direction of the dielectric green sheet laminate.

[0157] Optionally, the obtained dielectric green sheet laminate can be cut into a predetermined size by dicing or the like.

[0158] Also, the dielectric green sheet laminate can be solidified and dried to remove a plasticizer or the like as necessary, and can be barrel polished using a horizontal centrifugal barrel polishing machine or the like after solidification and drying. In barrel polishing, the dielectric green sheet laminate is put into a barrel container together with media and a polishing liquid, and by applying rotational motion, vibration, or the like to the barrel container, unnecessary portions such as burrs generated during cutting can be polished. Further, after barrel polishing, the dielectric green sheet laminate can be washed with a cleaning liquid such as water and dried.

[0159] The dielectric green sheet laminate is subjected to a debinding process and a firing process to obtain a capacitor body.

[0160] The conditions of the debinding process can be appropriately adjusted according to the main component composition of the dielectric layer and the main component composition of the internal electrode. For example, the heating rate during the debinding process may be 5°C / hour to 300°C / hour, the holding temperature may be 180°C to 400°C, and the temperature holding time may be 0.5 hour to 24 hours. The debinding atmosphere may be air or a reducing atmosphere.

[0161] The conditions of the firing process can be appropriately adjusted according to the main component composition of the dielectric layer and the main component composition of the internal electrodes. For example, the temperature during firing may be 1200°C to 1350°C, or 1220°C to 1300°C, and the time may be 0.5 hours to 8 hours, or 1 hour to 3 hours. The firing atmosphere may be a reducing atmosphere. For example, it may be an atmosphere in which a mixed gas of nitrogen gas (N2) and hydrogen gas (H2) is humidified.

[0162] After the firing process, annealing can be performed as necessary. Annealing is a process for re-oxidizing the dielectric layer. When the firing process is performed in a reducing atmosphere, annealing can be performed. The conditions of the annealing process can also be appropriately adjusted according to the main component composition of the dielectric layer, etc. For example, the temperature during annealing may be 950°C to 1150°C, the time may be 0 hours to 20 hours, and the heating rate may be 50°C / hour to 500°C / hour. The annealing atmosphere may be a humidified nitrogen gas (N2) atmosphere, and the oxygen partial pressure may be 1.0×10 -9 MPa to 1.0×10 -5 MPa.

[0163] In the debinding process, firing process, or annealing process, in order to humidify nitrogen gas, mixed gas, etc., for example, a wetter can be used. In this case, the water temperature may be 5°C to 75°C. The debinding process, firing process, and annealing process can be performed continuously or independently.

[0164] Optionally, surface treatment such as sandblasting, laser irradiation, or barrel polishing can be performed on the third and fourth surfaces of the obtained capacitor body. By performing such surface treatment, the ends of the first internal electrode and the second internal electrode are exposed on the outermost surfaces of the third and fourth surfaces, thereby improving the electrical connection between the first external electrode and the second external electrode and the first internal electrode and the second internal electrode, and facilitating the formation of an alloy portion.

[0165] Thereafter, a paste for forming a sintered metal layer can be applied to the outer surface of the obtained capacitor body and then sintered to form a sintered metal layer.

[0166] The paste for forming a sintered metal layer can contain a conductive metal and glass. Since the descriptions of the conductive metal and glass are as described above, repetitive explanations are omitted. Further, the paste for forming a sintered metal layer can selectively contain sub-components such as a binder, a solvent, a dispersant, a plasticizer, or oxide powder. For example, ethyl cellulose, acrylic, or butyral can be used as the binder, and organic solvents or aqueous solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene can be used as the solvent.

[0167] As a method for applying the paste for forming a sintered metal layer to the outer surface of the capacitor body, a dipping method, various printing methods such as screen printing, an application method using a dispenser, or a spraying method using a spray can be used. The paste for the sintered metal layer is applied to at least the third and fourth surfaces of the capacitor body, and can also be selectively applied to a part of the first surface, the second surface, the fifth surface, or the sixth surface where the band portions of the first external electrode and the second external electrode are formed.

[0168] Thereafter, the capacitor body 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 hour to 3 hours to form a sintered metal layer.

[0169] Optionally, a paste for forming a conductive resin layer can be applied to the outer surface of the obtained capacitor body and then cured to form a conductive resin layer.

[0170] The paste for forming a conductive resin layer can contain a resin and, optionally, a conductive metal or a non-conductive filler. Since the explanations regarding the conductive metal and the resin are as described above, repetitive explanations will be omitted. Also, the paste for forming a conductive resin layer can optionally contain sub-components such as a binder, a solvent, a dispersant, a plasticizer, or oxide powder. For example, as the binder, ethyl cellulose, acrylic, or butyral can be used, and as the solvent, organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or aqueous solvents can be used.

[0171] As an example, the method for forming a conductive resin layer can be to dip the capacitor body 110 into the paste for forming a conductive resin layer and then cure it, or to print the paste for forming a conductive resin layer on the surface of the capacitor body 110 by a screen printing method or a gravure printing method, or to apply the paste for forming a conductive resin layer on the surface of the capacitor body 110 and then cure it to form.

[0172] Thereafter, a plating layer is formed outside the conductive resin layer.

[0173] As an example, the plating layer can be formed by a plating method, and can also be formed by sputtering or electric deposition.

[0174] Hereinafter, specific embodiments of the invention will be presented. However, the embodiments described below are merely for specifically exemplifying or explaining the invention, and the scope of the invention should not be limited thereby.

Embodiment

[0175] Example 1 A slurry for a dielectric containing BaTiO3 was produced, and a dielectric green sheet was produced using the slurry for the dielectric with an on-roll coater of a head discharge method. Thereafter, a conductive paste for an internal electrode containing Ti2SnC was produced.

[0176] The conductive paste was printed on the surface of the dielectric green sheet, and a dielectric green sheet (width × length × height = 3.2 mm × 2.5 mm × 2.5 mm) having a conductive paste layer formed thereon was laminated and pressed to produce a dielectric green sheet laminate.

[0177] The dielectric green sheet laminate was subjected to a plasticizing process in a nitrogen atmosphere at 400 °C or lower and then fired under conditions of a firing temperature of 1300 °C or lower and a hydrogen concentration of 1.0% or lower to produce a multilayer capacitor according to Example 1.

[0178] Example 2 A multilayer capacitor according to Example 2 was produced in the same manner as in Example 1, except that a conductive paste for an internal electrode was produced by mixing Ti3AlC2 and Sn instead of Ti2SnC. At this time, the Sn was contained at 1% by weight with respect to 100% by weight of the conductive paste for an internal electrode.

[0179] Example 3 A multilayer capacitor according to Example 3 was produced in the same manner as in Example 2, except that a conductive paste for an internal electrode was produced by mixing Ti3AlC2 and Sn so that the Sn was contained at 5% by weight with respect to 100% by weight of the conductive paste for an internal electrode.

[0180] Example 4 A multilayer capacitor according to Example 4 was produced in the same manner as in Example 2, except that a conductive paste for an internal electrode was produced by mixing Ti3AlC2 and Sn so that the Sn was contained at 20% by weight with respect to 100% by weight of the conductive paste for an internal electrode.

[0181] Comparative Example 1 A multilayer capacitor according to Comparative Example 1 was manufactured in the same manner as in Example 1, except that a conductive paste for an internal electrode was manufactured by including a co-material (BaTiO3) with Ni instead of Ti2SnC.

[0182] Comparative Example 2 A multilayer capacitor according to Comparative Example 1 was manufactured in the same manner as in Example 1, except that a conductive paste for an internal electrode was manufactured by including Ti3AlC2 instead of Ti2SnC.

[0183] (Evaluation Example) Evaluation Example 1: Measurement of the presence or absence of Sn and the Sn content at the interface of the dielectric layer After the multilayer capacitors manufactured in Examples 1 to 4 and Comparative Examples 1 and 2 were put into an epoxy mixture and cured, the side surfaces in the L-axis direction and T-axis direction of the capacitor body were polished to the 1 / 2 point in the W-axis direction, fixed, and maintained in a vacuum atmosphere chamber. Cross-sectional samples were prepared by cutting in the L-axis direction and T-axis direction from the center in the W-axis direction of the capacitor body. Then, the cross-sectional samples were observed with a scanning electron microscope to prepare SEM images.

[0184] The presence or absence of Sn and the Sn content (atomic %) were measured by SEM-EDS analysis using the SEM images of the cross-sectional samples.

[0185] Evaluation Example 2: Electrode connectivity evaluation The electrode connectivity of the multilayer capacitors manufactured in Examples 1 to 4 and Comparative Examples 1 and 2 was evaluated.

[0186] First, the cross-sectional samples were observed with a scanning electron microscope (SEM) to prepare SEM images.

[0187] Then, an arbitrary internal electrode was selected, a virtual line was drawn in the L-axis direction, and the ratio of the length of the uncut internal electrode to the total length of the internal electrode was measured.

[0188] Taking the ratio measured for the multilayer capacitor of Comparative Example 1 as a reference (usually denoted as "○"), the ratios measured for the remaining Examples 1 to 4 and Comparative Example 2 are expressed as relative values. If the value is higher than that of Comparative Example 1, it is evaluated as excellent (denoted as "◎"), and if it is lower, it is evaluated as insufficient (denoted as "△"), as shown in Table 1 below.

[0189] Evaluation Example 3: Reliability (MTTF) Evaluation The reliability (MTTF, Mean Time To Failure, average time to failure) of the multilayer capacitors manufactured in Examples 1 to 4 and Comparative Examples 1 to 2 was evaluated.

[0190] 400 samples of the multilayer capacitor were prepared each, and a high-temperature load test was performed on them under the conditions of 125°C and 8V. The time when the insulation resistance becomes 10 kΩ or less was taken as the failure time.

[0191] The MTTF values for 400 samples were derived, and the MTTF value of Comparative Example 1 was taken as the reference value (usually denoted as "○"). If the MTTF values measured for the remaining Examples 1 to 4 and Comparative Example 2 are higher than that of Comparative Example 1, they are evaluated as excellent (denoted as "◎"), and if they are lower, they are evaluated as insufficient (denoted as "△"), as shown in Table 1 below.

[0192] Evaluation Example 4: Capacitance Evaluation The capacitance was measured using an LCR meter under the conditions of 1 kHz and AC 0.5V, with the capacitance of Comparative Example 1 as a reference (usually denoted as "○").

[0193] If the capacitances measured for the remaining Examples 1 to 4 and Comparative Example 2 are higher than that of Comparative Example 1, they are evaluated as excellent (denoted as "◎"), and if they are lower, they are evaluated as insufficient (denoted as "△"), as shown in Table 1 below.

[0194] Evaluation Example 5: BDV (Break down voltage) Evaluation The breakdown voltage (BDV) was measured by applying a voltage in a sweep manner from 0 V to 1.00000 V in steps of 1100 V using a Keithley measuring device model 2410, and the voltage value at the moment when the current value reached 20 mA was measured as the BDV value. The BDV was measured in a silicon oil bath.

[0195] Taking the BDV of Comparative Example 1 as the reference value (usually marked as "○"), if the BDV values measured in the remaining Examples 1 to 4 and Comparative Example 2 are higher than that of Comparative Example 1, they are evaluated as excellent (marked as "◎"), and if lower, they are evaluated as insufficient (marked as "△"), as shown in Table 1 below.

[0196]

Table 1

[0197] Referring to Table 1, in the case of the multilayer capacitors according to Examples 1 to 3, it can be confirmed that by using the MAX phase compound as the internal electrode to reduce the mismatch with the dielectric layer during firing, the electrode connectivity and capacitance increased compared to Comparative Example 1.

[0198] Also, in the case of the multilayer capacitors according to Examples 1 to 3, an appropriate amount of Sn was contained at the interface of the dielectric layer, and the dielectric layer and the internal electrode could be well joined, and it can be confirmed that the reliability of the capacitor was improved compared to Comparative Example 1.

[0199] Also, in the case of the multilayer capacitors according to Examples 1 to 3, it can be confirmed that by not using a co-material, the electrical characteristics (BDV) were improved compared to Comparative Example 1.

[0200] In the case of the multilayer capacitor according to Example 4, it can be confirmed that excessive addition of Sn excessively suppressed the grain growth of the dielectric in the dielectric layer, resulting in a decrease in electrode connectivity, electrical characteristics, and reliability.

[0201] In the case of the multilayer capacitor according to Comparative Example 2, since the interface portion of the dielectric layer does not contain Sn, the dielectric layer and the internal electrode are not well joined and are peeled off, and it can be confirmed that the electrode reliability, capacitance, etc. are lower than those of Comparative Example 1.

[0202] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited thereto, and various modifications can be made and implemented within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is natural that these also belong to the scope of the present invention.

Explanation of Reference Numerals

[0203] 100: Multilayer capacitor 110: Capacitor body 111: Dielectric layer 112, 113: Cover region 121: First internal electrode 122: Second internal electrode 131: First external electrode 132: Second external electrode

Claims

1. A capacitor body including a dielectric layer and internal electrodes, and external electrodes disposed outside the capacitor body, wherein the dielectric layer includes a central portion and an interface portion located on the surface of the central portion of the dielectric layer, and the interface portion of the dielectric layer contacts the internal electrodes, wherein the interface portion of the dielectric layer contains Sn, wherein the internal electrodes contain a first compound represented by the following Chemical Formula 1, a multilayer capacitor: 【Chemical Formula 1】 M ｎ＋１ A １－ｘ Sn ｘ X ｎ In Chemical Formula 1, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements, X includes C, N, or a combination thereof, 0 < x ≤ 1, and n is an integer from 1 to 4.

2. The multilayer capacitor according to Claim 1, wherein M includes Ti, Zr, Hf, Nb, or a combination thereof.

3. The first compound is Ti ２ SnC, Zr ２ SnC, Nb ２ SnC, Hf ２ SnC, Hf ２ SnN, Ti ３ SnC ２ , or a combination thereof, the multilayer capacitor according to claim 1.

4. The multilayer capacitor according to Claim 1, wherein the content of Sn in the interface portion of the dielectric layer is 0.1 at% or more and 0.5 at% or less.

5. The internal electrodes include a central portion and an interface portion located on the surface of the central portion of the internal electrodes, and the interface portion of the internal electrodes contacts the dielectric layer, wherein the central portion of the internal electrodes contains the first compound and a third compound represented by the following Chemical Formula 3, the multilayer capacitor according to Claim 1: 【Chemical Formula 3】 M ｎ＋１ X ｎ In Chemical Formula 3, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, X includes C, N, or a combination thereof, n is an integer from 1 to 4.

6. The multilayer capacitor according to Claim 5, wherein the interface portion of the internal electrodes contains Sn and the third compound.

7. The third compound is Ti ２ C, Zr ２ C, Nb ２ C, Hf ２ C, Hf ２ N, Ti ３ C ２ , or a combination thereof, the multilayer capacitor according to claim 5.

8. The multilayer capacitor according to Claim 6, wherein the content of Sn in the interface portion of the internal electrodes is 0.01 at% or more and 0.3 at% or less.

9. The central portion of the dielectric layer and the interface portion of the dielectric layer contain a main component and a sub-component, The main component is Ba ｍ TiO ３ (0.995 ≤ m ≤ 1.010), (Ba １－Ｘ Ca ｘ ) ｍ (Ti １－ｙ Zr ｙ )O ３ (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), Ba ｍ (Ti １－ｘ Zr ｘ )O ３ (0.995 ≤ m ≤ 1.010, x ≤ 0.10), (Ba １－Ｘ Ca ｘ ) ｍ (Ti １－ｙ Sn ｙ )O ３ (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), or a combination thereof, the multilayer capacitor according to claim 1.

10. The secondary component is dysprosium (Dy), manganese (Mn), vanadium (V), silicon (Si), aluminum (Al), barium (Ba), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), lanthanum (La), chromium (Cr), hafnium (Hf), yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof, and the multilayer capacitor according to claim 9.

11. A capacitor body including a dielectric layer and an internal electrode, and an external electrode disposed outside the capacitor body, The dielectric layer includes a central portion and an interface portion located on the surface of the central portion, and the interface portion of the dielectric layer is in contact with the internal electrode, The interface portion of the dielectric layer contains Sn, The internal electrode includes a second compound represented by the following Chemical Formula 2 and Sn, and a multilayer capacitor: [Chemical Formula 2] M ｎ＋１ AX ｎ In the above Chemical Formula 2, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, A includes any one or more selected from the group consisting of Group 11 elements to Group 16 elements, X includes C, N, or a combination thereof, n is an integer from 1 to 4.

12. The second compound is Ti ２ CdC, Sc ２ InC, Sc ２ SnC, Ti ２ AlC, Ti ２ GaC, Ti ２ InC, Ti ２ TlC, V ２ AlC, V ２ GaC, Cr ２ GaC, Ti ２ AlN, Ti ２ GaN, Ti ２ InN, V ２ GaN, Cr ２ GaN, Ti ２ GeC, Ti ２ SnC, Ti ２ PbC, V ２ GeC, Cr ２ AlC, Cr ２ GeC, V ２ PC, V ２ AsC, Ti ２ SC, Zr ２ InC, Zr ２ TlC, Nb ２ AlC, Nb ２ GaC, Nb ２ InC, Mo ２ GaC, Zr ２ InN, Zr ２ TlN, Zr ２ SnC, Zr ２ PbC, Nb ２ SnC, Nb ２ PC, Nb ２ AsC, Zr ２ SC, Nb ２ SC, Hf ２ InC, Hf ２ TlC, Ta ２ AlC, Ta ２ GaC, Hf ２ SnC, Hf ２ PbC, Hf ２ SnN, Hf ２ SC, Zr ２ AlC, Ti ２ ZnC, Ti ２ ZnN, V ２ ZnC, Nb ２ CuC, Mn ２ GaC, Mo ２ AuC, Ti ２ AuN, Ti ３ AlC ２ , Ti ３ GaC ２ , Ti ３ InC ２ , V ３ AlC ２ , Ti ３ SiC ２ , Ti ３ GeC ２ , Ti ３ SnC ２ , Ta ３ AlC ２ , Ti ３ ZnC ２ , Zr ３ AlC ２ , Ti ４ AlN ３ , V ４ AlC ３ , Ti ４ GaC ３ , Ti ４ SiC ３ , Ti ４ GeC ３ , Nb ４ AlC ３ , Ta ４ AlC ３ , (Mo, V) ４ AlC ３ , Mo ４ VAlC ４ The multilayer capacitor according to claim 11, comprising VAIC, or a combination thereof.

13. The content of Sn in the interface portion of the dielectric layer is 0.1 at% or more and 0.5 at% or less, and the multilayer capacitor according to claim 11.

14. The internal electrode includes a central portion and an interface portion located on the surface of the central portion of the internal electrode, and the interface portion of the internal electrode is in contact with the dielectric layer, The central portion of the internal electrode includes the second compound and a third compound represented by the following Chemical Formula 3, and the multilayer capacitor according to claim 11: [Chemical Formula 3] M ｎ＋１ X ｎ In the above Chemical Formula 3, M includes Ti, Zr, Hf, Sc, Cr, V, Nb, Ta, Mo, Mn, or a combination thereof, X includes C, N, or a combination thereof, n is an integer from 1 to 4.

15. The interface portion of the internal electrode includes Sn and the third compound, and the multilayer capacitor according to claim 14.

16. The third compound is Ti ２ C, Zr ２ C, Nb ２ C, Hf ２ C, Hf ２ N, Ti ３ C ２ or a combination thereof, the multilayer capacitor according to claim 14.

17. The laminated capacitor according to claim 15, wherein the content of Sn in the interface portion of the internal electrode is 0.01 at% or more and 0.3 at% or less.

18. The central portion and the interface portion of the dielectric layer contain a main component and a sub-component. The main component is Ba ｍ TiO ３ (0.995 ≤ m ≤ 1.010), (Ba １－Ｘ Ca ｘ ) ｍ (Ti １－ｙ Zr ｙ )O ３ (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), Ba ｍ (Ti １－ｘ Zr ｘ )O ３ (0.995 ≤ m ≤ 1.010, x ≤ 0.10), (Ba １－Ｘ Ca ｘ ) ｍ (Ti １－ｙ Sn ｙ )O ３ (0.995 ≤ m ≤ 1.010, 0 ≤ x ≤ 0.10, 0 < y ≤ 0.20), or a combination thereof, the multilayer capacitor according to claim 11.

19. The sub-component includes dysprosium (Dy), manganese (Mn), vanadium (V), silicon (Si), aluminum (Al), barium (Ba), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), lanthanum (La), chromium (Cr), hafnium (Hf), yttrium (Y), actinium (Ac), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof. The laminated capacitor according to claim 18.

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