Multilayer capacitor

Abstract

The present disclosure provides a multilayer capacitor, which may include: a capacitor body including a dielectric layer and an inner electrode; and an external electrode disposed outside the capacitor body, in which the capacitor body may include titanium (Ti) and indium (In), and in the entire capacitor body, a content of indium (In) may be 0.2 to 4 moles based on 100 moles of titanium (Ti).

Description

Technical Field

[0001] The present disclosure relates to a multilayer capacitor. Background Art

[0002] Recently, as electronic devices have rapidly become multifunctional and miniaturized, the size of electronic components has also rapidly decreased as performance has improved. In addition, the demand for high reliability of electrical devices used in automobiles, network equipment, etc. and industrial electronic components has greatly increased.

[0003] In order to meet such market demands, competition in the technical development of passive components such as inductors, capacitors or resistors is accelerating. In particular, for multilayer capacitors, which are passive components and whose use and applications are increasing, many efforts are needed to occupy the market by developing various products of multilayer capacitors (e.g., multilayer ceramic capacitors (MLCC)).

[0004] Also, the multilayer capacitor is manufactured by stacking dielectric layers and internal electrodes, and is used in various electronic devices such as mobile phones, laptop computers, televisions (TVs) (including liquid crystal displays (LCDs)), and the like.

[0005] With the recent technological progress, multilayer capacitors are required to be miniaturized and have high capacity, which requires reducing the thickness of the inner electrode and the thickness of the dielectric layer. As the thickness of the dielectric layer decreases, the electric field strength applied to each layer becomes relatively strong, which leads to a decrease in the reliability of the capacitor and a problem that the capacitance is also reduced due to the deterioration of the electrode connectivity. Summary of the invention

[0006] The present disclosure is directed to providing a multilayer capacitor capable of improving connectivity of internal electrodes and improving reliability.

[0007] However, the problems to be solved by the present disclosure are not limited to the above-mentioned problems, and can be variously extended within the scope of the technical ideas included in the embodiments.

[0008] A multilayer capacitor may include: a capacitor body including a dielectric layer and an inner electrode; and an outer electrode disposed outside the capacitor body.

[0009] The capacitor body may include titanium (Ti) and indium (In).

[0010] In the entire capacitor body, the content of indium (In) may be 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0011] The dielectric layer may include a main component including a barium titanate-based compound and a sub-component including indium (In).

[0012] The internal electrode may include indium (In) and a conductive metal other than indium.

[0013] The dielectric layer may include a central portion and an interface portion located on a surface of the central portion and contacting the internal electrode.

[0014] When the molar content of In based on 100 moles of Ti in the interface portion is A and the molar content of In based on 100 moles of Ti in the central portion is B, A>B may be satisfied.

[0015] A≥2B can be satisfied.

[0016] A may be 1.0 mol to 1.5 mol.

[0017] B may be 0.5 mol to 1.0 mol.

[0018] The internal electrode may include a central portion and an interface portion located on a surface of the central portion and contacting the dielectric layer.

[0019] When the molar content of In based on 100 mol of Ni in the interface portion is C and the molar content of In based on 100 mol of Ni in the central portion is D, C>D may be satisfied.

[0020] C≥3D can be satisfied.

[0021] C may be 0.5 mol to 1.0 mol.

[0022] D may be from 0.05 mol to 0.5 mol.

[0023] A multilayer capacitor may include: a capacitor body including a dielectric layer and an inner electrode; and an outer electrode disposed outside the capacitor body.

[0024] The multilayer capacitor may include titanium (Ti) and indium (In). In the entire multilayer capacitor, the content of indium (In) may be 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0025] The external electrode may include a sintered metal layer contacting the capacitor body.

[0026] The sintered metal layer may include indium (In) and a conductive metal other than indium.

[0027] The dielectric layer may include a central portion and an interface portion located on a surface of the central portion and contacting the internal electrode.

[0028] When the molar content of In based on 100 moles of Ti in the interface portion is A and the molar content of In based on 100 moles of Ti in the central portion is B, A>B may be satisfied.

[0029] A≥2B can be satisfied.

[0030] A may be 1.0 mol to 1.5 mol.

[0031] B may be 0.5 mol to 1.0 mol.

[0032] The internal electrode may include a central portion and an interface portion located on a surface of the central portion and contacting the dielectric layer.

[0033] When the molar content of In based on 100 mol of Ni in the interface portion is C and the molar content of In based on 100 mol of Ni in the central portion is D, C>D may be satisfied.

[0034] C≥3D can be satisfied.

[0035] C may be 0.5 mol to 1.0 mol.

[0036] D may be from 0.05 mol to 0.5 mol.

[0037] A multilayer capacitor may include: a capacitor body including an inner electrode including indium (In) and a dielectric layer including titanium (Ti) and indium (In); and an outer electrode disposed outside the capacitor body.

[0038] In the entire capacitor body, the content of indium (In) may be 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0039] Indium (In) may exist at an interface between the dielectric layer and the internal electrode.

[0040] The dielectric layer may include a main component including a barium titanate-based compound.

[0041] The inner electrode may further include a conductive metal other than indium.

[0042] The conductive metal may include nickel (Ni).

[0043] The barium titanate-based compound may include barium titanate.

[0044] A multilayer capacitor may include: a capacitor body including a dielectric layer and an inner electrode; and an outer electrode disposed outside the capacitor body.

[0045] The capacitor body may include titanium (Ti) and indium (In). In the entire capacitor body, the content of indium (In) may be 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0046] The dielectric layer may include a central portion and an interface portion located on a surface of the central portion and contacting the internal electrode.

[0047] When the molar content of In based on 100 moles of Ti in the interface portion is A and the molar content of In based on 100 moles of Ti in the central portion is B, A>B may be satisfied.

[0048] The internal electrode may include a central portion and an interface portion, the interface portion of the internal electrode being located on a surface of the central portion of the internal electrode and contacting the dielectric layer.

[0049] When a molar content of In based on 100 moles of Ni in the interface portion of the inner electrode is C and a molar content of In based on 100 moles of Ni in the central portion of the inner electrode is D, C>D may be satisfied.

[0050] A≥2B and C≥3D can be satisfied.

[0051] A may be 1.0 mol to 1.5 mol, B may be 0.5 mol to 1.0 mol, C may be 0.5 mol to 1.0 mol, and D may be 0.05 mol to 0.5 mol.

[0052] The dielectric layer may include a main component including a barium titanate-based compound and a sub-component including indium (In).

[0053] The internal electrode may include indium (In) and a conductive metal other than indium.

[0054] According to the multilayer capacitor according to the embodiment, connectivity of internal electrodes may be improved, and reliability may be improved.

[0055] Various beneficial advantages and effects of the present disclosure are not limited to the above description and will be more easily understood in the course of describing specific embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a perspective view showing a multilayer capacitor according to an embodiment.

[0057] Figure 2 It is along Figure 1 A cross-sectional view of the multilayer capacitor taken along line II'.

[0058] Figure 3 It is shown Figure 1 An exploded perspective view of the capacitor body.

[0059] Figure 4These are TEM images of the central portion of the dielectric layer (marked with "BT"), the interface between the dielectric layer and the internal electrode (marked with "Ni-BT interface"), and the central portion of the internal electrode (marked with "Ni") observed by transmission electron microscopy (TEM) in a cross-sectional sample of a multilayer capacitor.

[0060] Figure 5 yes Figure 4 TEM image of Ti mapped out.

[0061] Figure 6 yes Figure 4 TEM image of In mapped out.

[0062] Figure 7 yes Figure 4 TEM image of Ni mapped out. DETAILED DESCRIPTION

[0063] Hereinafter, the present disclosure will be described more fully with reference to the accompanying drawings showing embodiments of the present disclosure. The drawings and descriptions are considered to be illustrative rather than restrictive in nature. Throughout the specification, the same reference numerals represent the same elements. In addition, the accompanying drawings are provided only to allow easy understanding of the embodiments disclosed in the present specification, and should not be interpreted as limiting the spirit disclosed in the present specification, and it should be understood that the present disclosure includes all modifications, equivalents and alternatives that do not depart from the scope and spirit of the present disclosure. In addition, in the drawings, some components are exaggerated, omitted or schematically depicted, and the size of each component does not necessarily represent the actual size.

[0064] Unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0065] Throughout the specification, "stacking direction" refers to the direction in which constituent elements are stacked in sequence, and may also be a "thickness direction" perpendicular to the wide surface (main surface) of the constituent element at the sheet level, which corresponds to the T-axis direction. In addition, "side" refers to a direction extending from the edge of the constituent element at the sheet level in parallel to the wide surface (main surface), which may be a "plane direction", and corresponds to the L-axis direction in the drawings. In addition, the W-axis direction in the drawings may be a "width direction".

[0066] Hereinafter, various exemplary embodiments and modifications will be described in detail with reference to the accompanying drawings.

[0067] Figure 1 is a perspective view showing a multilayer capacitor 100 according to an embodiment. Figure 2 It is along Figure 1 1 is a cross-sectional view of the multilayer capacitor 100 taken along line II′ in FIG. Figure 3It is shown Figure 1 Exploded perspective view of the capacitor body 110 in FIG.

[0068] When defining directions to clearly describe the present embodiment, the L-axis direction, W-axis direction, and T-axis direction shown in the drawings represent 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 wide surface (main surface) of the sheet component, for example, it may be used with the same concept as the stacking direction of the stacked dielectric layer 111. The length direction (L-axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet component and substantially perpendicular to the thickness direction (T-axis direction), for example, it may be a direction in which the first external electrode 131 and the second external electrode 132 are opposite to each other. The width direction (W-axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet component and substantially perpendicular to the thickness direction (T-axis direction), and the length of the sheet component in the length direction (L-axis direction) may be longer than the length in the width direction (W-axis direction).

[0069] Reference Figures 1 to 3 , the multilayer capacitor 100 according to the embodiment may include a capacitor body 110 and external electrodes 131 and 132 disposed outside the capacitor body 110. The external electrodes 131 and 132 include a first external electrode 131 and a second external electrode 132 disposed at both ends of the capacitor body 110 opposite to each other in the length direction (L-axis direction).

[0070] According to the embodiment, the multilayer capacitor 100 includes a capacitor body 110 and external electrodes 131 and 132 arranged outside the capacitor body 110, the capacitor body 110 includes a dielectric layer 111 and internal electrodes 121 and 122, the capacitor body 110 includes titanium (Ti) and indium (In), and in the entire capacitor body 110, the content of indium (In) is 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0071] As an example, the capacitor body 110 may include titanium (Ti) and indium (In), for example, the dielectric layer 111 may include In as a dielectric subcomponent, and the internal electrodes 121 and 122 may include a Ni—In alloy.

[0072] According to another embodiment, a multilayer capacitor 100 includes a capacitor body 110 and external electrodes 131 and 132 arranged outside the capacitor body 110, the capacitor body 110 includes a dielectric layer 111 and internal electrodes 121 and 122, the multilayer capacitor 100 includes titanium (Ti) and indium (In), and in the entire multilayer capacitor, the content of indium (In) is 0.2 mol to 4 mol based on 100 mol of titanium (Ti).

[0073] For example, the sintered metal layer included in the external electrodes 131 and 132 may include indium (In).

[0074] Indium (In) is an element with a stronger tendency to oxidize than nickel (Ni). When such In is added to a conductive paste for forming an internal electrode and fired in a reducing atmosphere when manufacturing the multilayer capacitor 100, most of In is contained in the interface between the dielectric layer 111 and the internal electrodes 121 and 122.

[0075] Since a sufficient amount of In may be included in the interface between the dielectric layer 111 and the internal electrodes 121 and 122, the interface bonding strength between the dielectric layer 111 and the internal electrodes 121 and 122 may be improved, and In may serve as a semiconductor barrier wall that prevents electrons from moving from the internal electrodes 121 and 122 to the dielectric layer 111 and from moving from the dielectric layer 111 to the internal electrodes 121 and 122.

[0076] In addition, In included in the interface portion at one side of the dielectric layer 111 is oxidized to In 3+ , and replace the Ti site of the barium titanate-based compound. 3+ When In replaces the Ti site of barium titanate-based compounds, 3+ It can act as an acceptor, thereby improving the reliability of the multilayer capacitor 100.

[0077] In addition, In included in the interface portion at one side of the internal electrodes 121 and 122 may form an alloy with Ni as a metal included in the internal electrodes 121 and 122 , thereby improving smoothness and connectivity of the internal electrodes 121 and 122 .

[0078] When the content of In based on 100 mol of Ti in the entire capacitor body 110 is less than 0.2 mol, the effect of improving the reliability of the multilayer capacitor 100 is minimal because a sufficient amount of In is not contained in the interface between the dielectric layer 111 and the internal electrodes 121 and 122, and when the content of In based on 100 mol of Ti in the entire capacitor body 110 is more than 4 mol, the reliability of the multilayer capacitor 100 may be deteriorated because vacancies in the Ti sites in the barium titanate-based compound are eliminated.

[0079] In addition, when the content of In based on 100 mols of Ti in the entire multilayer capacitor 100 is less than 0.2 mol, the effect of improving the reliability of the multilayer capacitor 100 is extremely small because a sufficient amount of In is not contained in the interface between the dielectric layer 111 and the internal electrodes 121 and 122, and when the content of In based on 100 mols of Ti in the entire multilayer capacitor 100 is more than 4 mols, the reliability of the multilayer capacitor 100 may be deteriorated because vacancies in the Ti sites in the barium titanate-based compound are eliminated.

[0080] A method of measuring the content of In based on Ti in the capacitor body 110 or the multilayer capacitor 100 is as follows.

[0081] First, a sample in which the external electrodes 131 and 132 are removed from the multilayer capacitor 100 by grinding or polishing may be prepared, or the multilayer capacitor 100 in which the external electrodes 131 and 132 are not removed may be prepared as a sample.

[0082] Subsequently, 0.1 g of the sample was weighed and placed in a pressurized bottle, and a mixture was prepared by adding 6 ml of hydrochloric acid and 2 ml of nitric acid. The mixture was then heat treated at about 180 ° C for about 1 hour, and a dissolved sample was prepared by additional ultrasonic treatment. After filtering the dissolved sample through a 0.45 μm filter, the content (moles) of Ti and In included in the sample was analyzed by using an inductively coupled plasma emission spectrometer (ICP-OES). Even if not described in the present disclosure, other methods and / or other tools understood by those of ordinary skill in the art may be used.

[0083] The content of In based on Ti can be obtained by performing the above analysis on 5 or more multilayer capacitors and calculating the arithmetic mean of the measured values.

[0084] Capacitor body

[0085] The capacitor body 110 may have, for example, a substantially hexahedral shape.

[0086] In this embodiment, for the sake of convenience of explanation, in the capacitor body 110, surfaces opposite to each other in the thickness direction (T-axis direction) are defined as a first surface and a second surface, surfaces connected to the first surface and the second surface and opposite to each other in the length direction (L-axis direction) are defined as a third surface and a fourth surface, and surfaces connected to the first surface and the second surface, connected to the third surface and the fourth surface and opposite to each other in the width direction (W-axis direction) are defined as a fifth surface and a sixth surface.

[0087] For example, the first surface as the lower surface may be a mounting surface. In addition, the first to sixth surfaces may be flat, but the present embodiment is not limited thereto, and for example, the first to sixth surfaces may be curved surfaces having a convex central portion, and the edges of each surface as boundaries may be rounded.

[0088] The shape and size of the capacitor body 110 and the number of stacked dielectric layers 111 are not limited to those shown in the drawings of the present embodiment.

[0089] The capacitor body 110 is formed by stacking a plurality of dielectric layers 111 in a thickness direction (T-axis direction) and then firing them, and includes a plurality of dielectric layers 111 and a plurality of first internal electrodes 121 and a plurality of second internal electrodes 122, the first internal electrodes 121 and the second internal electrodes 122 being alternately arranged in the thickness direction (T-axis direction), and the dielectric layer 111 is interposed between the first internal electrodes 121 and the second internal electrodes 122.

[0090] Here, the respective dielectric layers 111 of the capacitor body 110 adjacent to each other may be integrated to such an extent that it is difficult to recognize a boundary therebetween without using a scanning electron microscope (SEM).

[0091] Furthermore, capacitor body 110 may include an active area and footprints 112 and 113 .

[0092] The active region contributes to generating capacitance of the multilayer capacitor 100. For example, the active region may be a region where the first and second internal electrodes 121 and 122 are stacked and overlap each other in a thickness direction (T-axis direction).

[0093] The cover regions 112 and 113 may be respectively disposed as thickness direction edge portions on the upper and lower surfaces of the active region opposite to each other in the thickness direction (T-axis direction). The cover regions 112 and 113 may be formed by stacking a single dielectric layer 111 or two or more dielectric layers 111 on the upper and lower surfaces of the active region, respectively.

[0094] In addition, the capacitor body 110 may further include a side covering area. The side covering area is an edge portion and may be respectively provided on two side surfaces of the effective area that are opposite to each other in the width direction (W-axis direction). Such a side covering area may be formed by coating a conductive paste for forming an internal electrode only on a portion of the surface of the dielectric green sheet except for a portion where the side covering area is to be formed, and then obtaining the side covering area by stacking, cutting, and sintering operations; or, coating a conductive paste for an internal electrode on the entire surface of the dielectric green sheet, obtaining a dielectric green sheet stack by stacking and cutting, and then obtaining the side covering area by stacking dielectric green sheets not coated with the conductive paste on both side surfaces of the dielectric green sheet stack and firing them.

[0095] The cover regions 112 and 113 and the side cover regions serve to prevent damage to the first and second internal electrodes 121 and 122 due to physical stress and / or chemical stress.

[0096] Dielectric layer

[0097] The dielectric layer 111 may include a dielectric material, and the dielectric material may include a main component and a subsidiary component.

[0098] The main component is a dielectric matrix material with a high dielectric constant and contributes to the capacitance of the multilayer capacitor 100.

[0099] As an example, the main component can be a barium titanate-based compound. For example, it can be a dielectric material containing 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.

[0100] As an example, the main component may 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.

[0101] As an example, the secondary component may include indium (In), and indium (In) can be oxidized to In 3+ , and can replace the Ti site of the barium titanate-based compound.

[0102] In addition, the secondary component may further include dysprosium (Dy), vanadium (V), manganese (Mn), chromium (Cr), silicon (Si), aluminum (Al), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), barium (Ba), lanthanum (La), 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), hafnium (Hf) or a combination thereof. The dielectric material may also contain ceramic additives, organic solvents, binders, dispersants or a combination thereof.

[0103] As an example, the dielectric material may include a plurality of dielectric grains, and at least one of the plurality of dielectric grains may have a core-shell structure.

[0104] The dielectric grain having the core-shell structure includes a core and a shell surrounding at least a portion of the core. For example, indium (In) included in the subcomponent may be contained in the region of the shell.

[0105] The core and shell have different molar ratios of secondary components to the main component, for example, the molar ratio of secondary components to the main component can change rapidly at the boundary between the core and the shell. Therefore, the boundary between the core and the shell can be easily identified, which can be confirmed by transmission electron microscopy-energy dispersive X-ray spectrometer (TEM-EDX) analysis.

[0106] For example, the core may not include a secondary component, but if it does, it only includes trace amounts of the secondary component. Thus, the core may consist of only a pure primary component without impurities, but the pure primary component may generally have a higher dielectric constant than the primary component doped with the impurity element. Thus, the core may be used to maintain the dielectric constant.

[0107] Compared with the core, the shell includes more secondary components. In the shell, the secondary components doped in the B site of the main component (perovskite ABO3 structure) have the effect of improving the band gap energy of other rare earth elements and doping elements diffused into the dielectric grains. Therefore, the secondary components can play the role of a barrier to inhibit the diffusion of other rare earth elements and doping elements into the dielectric grains. The shell can play the role of inhibiting the growth of dielectric grains, and can contribute to the micronization of dielectric grains. In addition, in the shell, the secondary components doped in the A site of the main component can play the role of improving reliability and dielectric constant.

[0108] As an example, In may be located in the central portion of the dielectric layer 111 and on the surface of the central portion of the dielectric layer 111. In may be included in an interface portion of the dielectric layer 111 contacting the internal electrodes 121 and 122.

[0109] The central portion of the dielectric layer 111 may refer to a central point between a point on one side surface of the dielectric layer and a point on the other side surface of the dielectric layer at the shortest distance from the point in the T-axis direction in a cross section taken in the L-axis direction and the T-axis direction at the center of the capacitor body 110 in the W-axis direction. In addition, in addition to the central point, the central portion of the dielectric layer 111 may also refer to an area within ±30% of the thickness of the dielectric layer in the T-axis direction based on the central point.

[0110] The interface portion of the dielectric layer 111 is a region other than the central portion of the dielectric layer 111, and may indicate a point spaced 2 nm apart from an interface provided between the dielectric layer 111 and the internal electrodes 121 and 122 in the T-axis direction toward the central portion of the dielectric layer 111. In addition, in addition to the point, the interface portion of the dielectric layer may also indicate a region within ±30% of the thickness of the dielectric layer in the T-axis direction based on the point.

[0111] In an embodiment, when the molar content of In based on 100 moles of Ti in the interface portion of the dielectric layer 111 is referred to as A, and the molar content of In based on 100 moles of Ti in the central portion of the dielectric layer 111 is referred to as B, A>B may be satisfied. For example, A and B may satisfy A≥1.5B or A≥2B.

[0112] In an embodiment, the content A of In based on 100 mol of Ti in the interface portion of the dielectric layer 111 may be 1.0 mol to 1.5 mol, for example, 1.0 mol to 1.4 mol or 1.2 mol to 1.4 mol.

[0113] In an embodiment, the content B of In based on 100 mol of Ti in the central portion of the dielectric layer 111 may be 0.5 mol to 1.0 mol, for example, 0.5 mol to 0.8 mol or 0.6 mol to 0.8 mol.

[0114] When the above numerical range is satisfied, since a sufficient amount of In is included in the interface between the dielectric layer and the internal electrode, the interface bonding strength between the dielectric layer and the internal electrode may be improved, and a multilayer capacitor with improved reliability may be implemented.

[0115] The In content B in the central portion of the dielectric layer 111 and the In content A in the interface portion of the dielectric layer 111 can be measured as follows.

[0116] First, after the multilayer capacitor 100 is placed in the epoxy resin mixture and cured, the side surfaces of the multilayer capacitor 100 in the L-axis direction and the T-axis direction are polished to the 1 / 2 point of the capacitor body 110 in the W-axis direction, fixed, and kept in a vacuum atmosphere chamber, thereby preparing a cross-sectional sample of the multilayer capacitor 100 cut in the L-axis direction and the T-axis direction at the center of the capacitor body 110 in the W-axis direction (hereinafter referred to as a "cross-sectional sample").

[0117] Then, by observing the cross-sectional sample with a transmission electron microscope (TEM), the Figure 4 Transmission electron microscopy images are shown.

[0118] Figure 4These are TEM images of the central portion of the dielectric layer (marked with "BT"), the interface between the dielectric layer and the internal electrode (marked with "Ni-BT interface"), and the central portion of the internal electrode (marked with "Ni") observed by transmission electron microscopy (TEM) in a cross-sectional sample of a multilayer capacitor. Figure 5 yes Figure 4 TEM image of Ti mapped out. Figure 6 yes Figure 4 TEM image of In mapped out. Figure 5 to Figure 6 The light grey areas in the indicate the presence of the identified elements.

[0119] Reference Figures 4 to 6 , select 5 or more arbitrary dielectric layers 111 in the TEM image of the cross-sectional sample, and select 5 equally spaced points corresponding to the central portion of the dielectric layer 111 and 5 equally spaced points corresponding to the interface portion of the dielectric layer 111. The selected points are subjected to transmission electron microscopy (TEM)-energy dispersive X-ray spectroscopy (EDS) quantitative analysis. Figure 5 and Figure 6 As shown, after mapping Ti and In out of the cross-sectional sample, the contents of Ti and In are measured, and the values ​​of A and B can be obtained by calculating the arithmetic mean of the measured values. Even if not described in the present disclosure, other methods and / or other tools understood by those of ordinary skill in the art may be used.

[0120] 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 2.5 μm or less, 1.5 μm or less, or 0.5 μm or less. When the average thickness of the dielectric layer 111 is less than 0.05 μm, it may be difficult to confirm the improvement of reliability.

[0121] The average thickness of the dielectric layer 111 may be measured as follows.

[0122] First, a scanning electron microscope image obtained by observing a cross-sectional sample with a scanning electron microscope (SEM) is prepared.

[0123] In a scanning electron microscope (SEM) image of a cross-sectional sample, the average thickness of the dielectric layer 111 can be obtained in the following manner: the central point of the dielectric layer 111 in the length direction (L-axis direction) or the width direction (W-axis direction) is used as a reference point, and the arithmetic mean of the thickness of the dielectric layer 111 at 10 points spaced apart from the reference point at predetermined intervals is calculated.

[0124] The predetermined interval of the 10 dots may be adjusted according to the scale of a scanning electron microscope (SEM) image, for example, from about 1 μm to about 100 μm, from about 1 μm to about 50 μm, or from about 1 μm to about 10 μm. The interval here may refer to the interval between two adjacent dots.

[0125] Here, the 10 points must all be located in the dielectric layer 111 , but when the 10 points are not all located in the dielectric layer 111 , the reference point may be repositioned or the intervals of the 10 points may be adjusted.

[0126] Inner electrode

[0127] The first internal electrode 121 and the second internal electrode 122 are electrodes having different polarities and are alternately arranged opposite to each other along the thickness direction, and the dielectric layer 111 is interposed between the first internal electrode 121 and the second internal electrode 122, and one end of the first internal electrode 121 and one end of the second internal electrode 122 can be exposed through the third surface and the fourth surface of the capacitor body 110, respectively.

[0128] The first and second internal electrodes 121 and 122 may be electrically insulated from each other by a dielectric layer 111 disposed therebetween.

[0129] Ends of the first and second internal electrodes 121 and 122 alternately exposed through the third and fourth surfaces of the capacitor body 110 are respectively connected to the first and second external electrodes 131 and 132 to be electrically connected.

[0130] In an embodiment, the first and second internal electrodes 121 and 122 may include a conductive metal. As an example, the conductive metal may include a metal such as Ni, Cu, Ag, Pd, Au, or an alloy thereof (eg, Ag-Pd alloy).

[0131] The first internal electrode 121 and the second internal electrode 122 may further include indium (In), and may include an alloy of the above-mentioned conductive metal and indium (In). For example, when the above-mentioned conductive metal is Ni, the first internal electrode 121 and the second internal electrode 122 may include Ni and In, for example, a Ni-In alloy. In other words, the first internal electrode 121 and the second internal electrode 122 may include indium (In) and a conductive metal other than indium (In). In addition, the first internal electrode 121 and the second internal electrode 122 may include dielectric particles having the same composition as the ceramic material included in the dielectric layer 111.

[0132] The first and second internal electrodes 121 and 122 may be formed using a conductive paste including a conductive metal, and a screen printing method, a gravure printing method, or the like may be used as a printing method of the conductive paste.

[0133] As an example, In may be located in 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. In may be included in interface portions of the internal electrodes 121 and 122 contacting the dielectric layer 111.

[0134] The central portion of the internal electrodes 121 and 122 may refer to a central point between a point on one side surface of the internal electrode and a point on the other side surface of the internal electrode at the shortest distance from the point in the T-axis direction in a cross section taken in the L-axis direction and the T-axis direction at the center of the capacitor body 110 in the W-axis direction. In addition, in addition to the central point, the central portion of the internal electrodes 121 and 122 may also refer to an area within ±30% of the thickness of the internal electrode in the T-axis direction based on the central point.

[0135] The interface portion of the internal electrodes 121 and 122 may be a region other than the central portion of the internal electrodes 121 and 122, and may indicate a point spaced 2 nm apart from an interface provided between the dielectric layer 111 and the internal electrodes 121 and 122 in the T-axis direction toward the central portion of the internal electrodes 121 and 122. In addition, in addition to the point, the interface portion of the internal electrodes 121 and 122 may also indicate a region within ±30% of the thickness of the internal electrode in the T-axis direction based on the point.

[0136] In an embodiment, when the molar content of In based on 100 moles of Ni in the interface portion of the internal electrodes 121 and 122 (e.g., the average molar content) is referred to as C, and the molar content of In based on 100 moles of Ni in the central portion of the internal electrodes 121 and 122 (e.g., the average molar content) is referred to as D, C>D may be satisfied. For example, C and D may satisfy C≥1.5D, and, for example, may satisfy C≥2D or C≥3D.

[0137] In an embodiment, an average content C of In based on 100 mol of Ni in the interface portion of the internal electrodes 121 and 122 may be 0.5 mol to 1.0 mol, for example, 0.5 mol to 0.8 mol or 0.6 mol to 0.8 mol.

[0138] In an embodiment, an average content D of In based on 100 mol of Ni in the central portion of the internal electrodes 121 and 122 may be 0.05 mol to 0.5 mol, for example, 0.05 mol to 0.3 mol or 0.1 mol to 0.3 mol.

[0139] When the above numerical range is satisfied, since a sufficient amount of In is included in the interface between the dielectric layer 111 and the internal electrodes 121 and 122, the interface bonding strength between the dielectric layer 111 and the internal electrodes 121 and 122 can be improved, and the smoothness and connectivity of the internal electrodes 121 and 122 can be improved.

[0140] An average content D of In in the central portions of the internal electrodes 121 and 122 and an average content C of In in the interface portions of the internal electrodes 121 and 122 may be measured as follows.

[0141] Figure 4 These are TEM images of the central portion of the dielectric layer (marked with "BT"), the interface between the dielectric layer and the internal electrode (marked with "Ni-BT interface"), and the central portion of the internal electrode (marked with "Ni") observed by transmission electron microscopy (TEM) in a cross-sectional sample of a multilayer capacitor. Figure 6 yes Figure 4 TEM image of In mapped out. Figure 7 yes Figure 4 TEM image of Ni mapped out. Figure 6 to Figure 7 The light grey areas in the indicate the presence of the identified elements.

[0142] In such Figure 4 Five or more arbitrary internal electrodes 121 and 122 are selected in the TEM image of the cross-sectional sample shown, and five equally spaced points corresponding to the central portions of the internal electrodes 121 and 122 and five equally spaced points corresponding to the interface portions of the internal electrodes 121 and 122 are selected.

[0143] The selected points were subjected to transmission electron microscopy (TEM)-energy dispersive X-ray spectroscopy (EDS) quantitative analysis. Figure 6 and Figure 7 As shown, the contents of Ni and In are measured after mapping Ni and In in the cross-sectional sample, and the values ​​of C and D can be obtained by calculating the arithmetic mean of the measured values. Even if not described in the present disclosure, other methods and / or other tools understood by those of ordinary skill in the art may be used.

[0144] As examples, the average thickness of the first internal electrode 121 and / or 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 1 μm or less, 0.5 μm or less, 0.4 μm or less, or 0.3 μm or less.

[0145] The average thickness of the first internal electrode 121 and / or the second internal electrode 122 may be measured as follows.

[0146] In a scanning electron microscope (SEM) image of a cross-sectional sample, the average thickness of the internal electrode can be obtained as follows: taking the arithmetic mean of the thicknesses of the first internal electrode 121 and / or the second internal electrode 122 at 10 points spaced apart from a reference point at predetermined intervals, wherein the reference point is the central point of the first internal electrode 121 and / or the second internal electrode 122 in the length direction (L-axis direction) or the width direction (W-axis direction).

[0147] The predetermined interval of the 10 dots may be adjusted according to the scale of a scanning electron microscope (SEM) image, for example, from about 1 μm to about 100 μm, from about 1 μm to about 50 μm, or from about 1 μm to about 10 μm. The interval here may refer to the interval between two adjacent dots.

[0148] Here, all 10 points must be located within the first inner electrode 121 and / or the second inner electrode 122, but when all 10 points cannot be located within the first inner electrode 121 and / or the second inner electrode 122, the reference point may be repositioned or the intervals between the 10 points may be adjusted.

[0149] External electrode

[0150] The first and second external electrodes 131 and 132 are supplied with voltages having different polarities and are electrically connected to exposed portions of the first and second internal electrodes 121 and 122 , respectively.

[0151] According to 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. At this time, the capacitance of the multilayer capacitor 100 is proportional to the overlapping area in which the first internal electrode 121 and the second internal electrode 122 overlap each other along the T-axis direction in the active region.

[0152] The first outer electrode 131 may include a first connection portion arranged on the third surface of the capacitor body 110 and connected to the first inner electrode 121, and may also include a first band portion arranged at each corner where the third surface of the capacitor body 110 intersects with the first and second surfaces and / or the fifth and sixth surfaces of the capacitor body 110, and the second outer electrode 132 may include a second connection portion arranged on the fourth surface of the capacitor body 110 and connected to the second inner electrode 122, and may also include a second band portion arranged at each corner where the fourth surface of the capacitor body 110 intersects with the first and second surfaces and / or the fifth and sixth surfaces of the capacitor body 110.

[0153] The first band portion may also extend from the first connection portion to a portion of the first surface and a portion of the second surface and / or a portion of the fifth surface and a portion of the sixth surface of the capacitor body 110, and the second band portion may also extend from the second connection portion to a portion of the first surface and a portion of the second surface and / or a portion of the fifth surface and a portion of the sixth surface of the capacitor body 110. The first band portion and the second band portion may be used to improve the bonding strength of the first external electrode 131 and the second external electrode 132 to the capacitor body 110, respectively.

[0154] For example, the first and second external electrodes 131 and 132 respectively include a sintered metal layer contacting the capacitor body 110 , a conductive resin layer configured to cover the sintered metal layer, and a plated layer configured to cover the conductive resin layer.

[0155] The sintered metal layer may include a conductive metal.

[0156] The sintered metal layer may include at least one of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti) and lead (Pb) (e.g., alloys thereof) as a conductive metal, for example, the sintered metal layer including copper (Cu) may mean including a copper (Cu) alloy. The sintered metal layer may also include indium (In). For example, when the conductive metal is Cu, the sintered metal layer may include Cu and In, and as an example, may include a Cu-In alloy. When the conductive metal includes copper, a metal other than copper may be included in an amount less than or equal to about 5 moles based on 100 moles of copper.

[0157] As an example, the sintered metal layer may further include glass. In this case, the sintered metal layer may include a composition in which an oxide is mixed with glass, for example, the oxide may be at least one selected from silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide. The transition metal may be selected from zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni); the alkali metal may be selected from lithium (Li), sodium (Na), and potassium (K); and the alkaline earth metal may be selected from magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0158] Optionally, the conductive resin layer is formed on the sintered metal layer, for example, the conductive resin layer may be formed to completely cover the sintered metal layer. In addition, the first and second external electrodes 131 and 132 may not include the sintered metal layer, and in this case, the conductive resin layer may directly contact the capacitor body 110.

[0159] The conductive resin layer may extend to the first and second surfaces and / or the fifth and sixth surfaces of the capacitor body 110, and the length of the region (i.e., the band portion) where the conductive resin layer extends to the first and second surfaces and / 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 to the first and second surfaces and / or the fifth and sixth surfaces of the capacitor body 110. That is, the conductive resin layer may be formed on the sintered metal layer and completely cover the sintered metal layer.

[0160] The conductive resin layer includes resin and conductive metal.

[0161] The resin included in the conductive resin layer is not particularly limited as long as it has adhesiveness and impact absorption and can be mixed with the conductive metal powder to form a paste. For example, the resin included in the conductive resin layer may include phenolic resin, acrylic resin, silicone resin, epoxy resin or polyimide resin.

[0162] The conductive metal included in the conductive resin layer serves to be electrically connected to the first and second internal electrodes 121 and 122 or the sintered metal layer.

[0163] The conductive metal included in the conductive resin layer may have a spherical shape, a flake shape, or a combination thereof. That is, the conductive metal may be formed only in a flake shape, or may be formed only in a spherical shape, or may have a mixed shape of a flake shape and a spherical shape.

[0164] Here, the spherical shape may also include a shape that is not a perfect sphere, and may include, for example, a shape in which the length ratio between the major axis and the minor axis (major axis / minor axis) may be less than or equal to about 1.45. The flake shape means a flat and elongated shape, and is not particularly limited, for example, the length ratio between the major axis and the minor axis (major axis / minor axis) may be greater than or equal to about 1.95.

[0165] The first and second external electrodes 131 and 132 may further include a plating layer outside the conductive resin layer.

[0166] The plating layer may include a single nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti) or lead (Pb) or an alloy thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or may have a form in which a nickel (Ni) plating layer and a tin (Sn) plating layer are stacked in sequence, or a tin (Sn) plating layer, a nickel (Ni) plating layer and a tin (Sn) plating layer may be stacked in sequence. In addition, the plating layer may include a plurality of nickel (Ni) plating layers and / or a plurality of tin (Sn) plating layers.

[0167] The plating layer may improve the mountability, structural reliability, exterior durability, heat resistance, and equivalent series resistance (ESR) of the multilayer capacitor 100 with a board.

[0168] Method for manufacturing multilayer capacitor

[0169] A method of manufacturing a multilayer capacitor according to another embodiment may include: manufacturing a capacitor body including a dielectric layer and an inner electrode; and forming an outer electrode outside the capacitor body.

[0170] First, the production of the capacitor body will be described.

[0171] In the manufacturing process of the capacitor body, a dielectric paste for forming a dielectric layer after firing and a conductive paste for forming an internal electrode after firing are prepared.

[0172] For example, the dielectric paste is prepared by the following method. Dielectric powder is uniformly mixed by a method such as wet mixing, dried, and then heat-treated under predetermined conditions to obtain a calcined powder. An organic vehicle or an aqueous vehicle is added to the obtained calcined powder and kneaded to prepare the dielectric paste.

[0173] The dielectric green sheet is obtained by forming the obtained dielectric paste into a sheet using a technique such as a doctor blade method. In addition, if necessary, the dielectric paste may contain an additive selected from various dispersants, plasticizers, binders, subcomponent compounds, and glass.

[0174] The conductive paste for the internal electrode is prepared by kneading a conductive powder made of a conductive metal or an alloy thereof with a binder or a solvent.

[0175] As an example, the conductive paste for the internal electrode may be prepared to include indium (In).

[0176] If necessary, the conductive paste for the internal electrode may include ceramic powder (eg, barium titanate powder) as a co-material (ie, the same material as that of the dielectric layer). The co-material may be used to suppress sintering of the conductive powder during a firing process.

[0177] On the surface of the dielectric green sheet, a conductive paste for the internal electrode is applied in a predetermined pattern by various printing methods such as a screen printing method or a transfer method. After stacking a plurality of dielectric green sheets on which the internal electrode pattern is formed, a dielectric green sheet stack is obtained by pressing in a stacking direction. At this time, the dielectric green sheets not including the internal electrode pattern may be stacked so that the dielectric green sheets may be disposed on the upper and lower surfaces of the dielectric green sheet stack in the stacking direction.

[0178] Optionally, the obtained dielectric green sheet stack may be cut into a predetermined size by dicing or the like.

[0179] In addition, the dielectric green sheet stack may be cured and dried to remove the plasticizer and the like, and after curing-drying, barrel polishing may be performed by using a centrifugal barrel machine and the like. In barrel polishing, the dielectric green sheet stack is added to a barrel container containing a medium and a polishing liquid, and then a rotational motion or vibration is applied to the barrel container to polish unnecessary portions such as burrs generated during cutting. In addition, after barrel polishing, the dielectric green sheet stack is washed with a cleaning solution such as water and the like and dried.

[0180] The dielectric green sheet stack is processed to remove the binder and fired to obtain a capacitor body.

[0181] The binder removal may be performed under conditions appropriately adjusted according to the main component composition of the dielectric layer and / or the main component composition of the inner electrode. For example, the binder removal may be performed by increasing the temperature at about 5° C. / hour to about 300° C. / hour and maintaining at about 180° C. to about 400° C. for about 0.5 hour to about 24 hours. The binder removal may be performed in an air atmosphere or a reducing atmosphere.

[0182] The firing treatment may be performed under conditions appropriately adjusted according to the main component composition of the dielectric layer and / or the main component composition of the inner electrode. For example, the firing may be performed in the following manner: at about 1200° C. to about 1350° C. (e.g., about 1220° C. to about 1300° C.) for about 0.5 hour to about 8 hours (e.g., about 1 hour to about 3 hours). The firing may be performed in a reducing atmosphere (e.g., an atmosphere in which a mixed gas of nitrogen (N2) and hydrogen (H2) is humidified). When the inner electrode includes nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure under the firing atmosphere may be about 1.0×10 -14 MPa to about 1.0×10 -10 MPa.

[0183] After the firing process, annealing may be performed if necessary. Annealing is performed to reoxidize the dielectric layer, and annealing may be performed when firing is performed in a reducing atmosphere. Annealing may be performed under conditions appropriately adjusted according to the main component composition of the dielectric layer, etc. For example, annealing may be performed by increasing the temperature at about 50°C / hour to about 500°C / hour, and maintaining at about 950°C to about 1150°C for about 0 hours to about 20 hours. Annealing may be performed in a humidified nitrogen (N2) atmosphere, wherein the oxygen partial pressure may be about 1.0×10 -9 MPa to about 1.0×10 -5 MPa.

[0184] In the binder removal process, the firing process or the annealing process, a wetting agent or the like may be used to wet nitrogen gas, mixed gas, etc., wherein the temperature of the wetting agent may be about 5° C. to about 75° C. The binder removal process, the firing process and the annealing process may be performed continuously or independently.

[0185] Optionally, the third surface and the fourth surface of the obtained capacitor body may be surface-treated by sandblasting, laser irradiation, barrel polishing, etc. This surface treatment may expose the ends of the first inner electrode and the second inner electrode on the third surface and the fourth surface, thereby improving the electrical connection between the first outer electrode and the first inner electrode and the electrical connection between the second outer electrode and the second inner electrode, and facilitating the formation of an alloy portion.

[0186] Subsequently, a paste for a sintered metal layer may be coated on the outer surface of the obtained capacitor body and then sintered to form a sintered metal layer.

[0187] The paste for forming the sintered metal layer may include conductive metal and glass. Conductive metal and glass are the same as above-mentioned conductive metal and glass, and will not be repeated. In addition, the paste for forming the sintered metal layer may optionally include the secondary components such as adhesive, solvent, dispersant, plasticizer or oxide powder. For example, adhesive may include ethyl cellulose, acrylic acid, butyral etc., and solvent may include organic solvent (such as, terpineol, butyl carbitol, ethanol, methyl ethyl ketone, acetone or toluene) or aqueous solvent.

[0188] The method of coating the paste for forming the sintered metal layer on the outer surface of the capacitor body may include a dipping method, various printing methods (such as screen printing, etc.), a coating method by using a dispenser, a spraying method by using a sprayer, etc. The paste for forming the sintered metal layer may be coated on at least the third surface and the fourth surface of the capacitor body, and optionally, on portions of the first surface, the second surface, the fifth surface, and / or the sixth surface where the band portions of the first external electrode and the second external electrode are to be formed.

[0189] Thereafter, the capacitor body on which the paste for forming a sintered metal layer is applied is dried and sintered at a temperature of about 700° C. to about 1000° C. for about 0.1 hour to about 3 hours to form a sintered metal layer.

[0190] Optionally, on the outer surface of the obtained capacitor body, a paste for forming a conductive resin layer is applied and cured to form a conductive resin layer.

[0191] The paste for forming the conductive resin layer may include resin and conductive metal, and optionally, may also include non-conductive filler. Conductive metal and resin are identical with above-mentioned conductive metal and resin, and will not be repeated. In addition, optionally, the paste for forming the conductive resin layer may include the secondary component such as adhesive, solvent, dispersant, plasticizer, oxide powder. For example, adhesive may include ethyl cellulose, acrylic acid, butyral etc., and solvent may use organic solvent (such as, terpineol, butyl carbitol, ethanol, methyl ethyl ketone, acetone or toluene) or aqueous solvent.

[0192] For example, the method of forming the conductive resin layer may include: immersing the capacitor body 110 in a paste for forming the conductive resin layer and curing it; screen printing or gravure printing the paste for forming the conductive resin layer on the surface of the capacitor body 110 and curing it; or coating the paste for forming the conductive resin layer on the surface of the capacitor body 110 and then curing it.

[0193] Subsequently, a plating layer is formed on the outside of the conductive resin layer.

[0194] For example, the plated layer may be formed by a plating method, or may be formed by sputtering or electroplating (electrodeposition).

[0195] Hereinafter, specific embodiments of the present disclosure are presented. However, the examples described below are only used to specifically illustrate or explain the present disclosure, and the scope of the present disclosure is not limited thereto.

[0196] (Example)

[0197] Example 1

[0198] The multilayer capacitor according to Example 1 was manufactured by weighing In so that the In content within the multilayer capacitor could be 0.21 mol based on 100 mol of Ti, and adjusting the oxygen partial pressure condition.

[0199] The In content in the multilayer capacitor can be obtained as follows.

[0200] First, a multilayer capacitor according to Example 1 was prepared as a sample, 0.1 g of the sample was weighed and placed in a pressurized bottle, and a mixture was prepared by adding 6 ml of hydrochloric acid and 2 ml of nitric acid. The mixture was then heat treated at about 180 ° C for about 1 hour, and a dissolved sample was prepared by additional ultrasonic treatment. After filtering the dissolved sample through a 0.45 μm filter, the content (molar) of Ti and In included in the sample was analyzed by using an inductively coupled plasma emission spectrometer (ICP-OES). The average content of In based on Ti can be obtained by performing the above analysis on 5 or more multilayer capacitors and taking the arithmetic mean of the measured values.

[0201] In addition, in the multilayer capacitor according to Example 1, the average content A of In in the interface portion of the dielectric layer and the average content B of In in the central portion of the dielectric layer (based on 100 mol of Ti) were measured, and the results are shown in Table 1 below. In addition, in the multilayer capacitor according to Example 1, the average content C of In in the interface portion of the inner electrode and the average content D of In in the central portion of the inner electrode (based on 100 mol of Ni) were measured, and the results are shown in Table 2 below.

[0202] Specifically, after the multilayer capacitor according to Example 1 is placed in an epoxy resin mixture and then cured, the side surfaces of the multilayer capacitor in the L-axis direction and the T-axis direction are polished to the 1 / 2 point of the capacitor body in the W-axis direction, fixed, and maintained in a vacuum atmosphere chamber, thereby preparing a cross-sectional sample of the multilayer capacitor cut in the L-axis direction and the T-axis direction at the center of the capacitor body 110 in the W-axis direction.

[0203] Subsequently, after acquiring a TEM image of the cross-sectional sample, 5 or more arbitrary dielectric layers and 5 or more arbitrary internal electrodes are selected from the image. Then, 5 equally spaced points corresponding to the central portion of the dielectric layer and 5 equally spaced points corresponding to the interface portion of the dielectric layer are selected, and 5 equally spaced points corresponding to the central portion of the internal electrode and 5 equally spaced points corresponding to the interface portion of the internal electrode are selected.

[0204] The Ti content and In content of the selected points were quantitatively analyzed and measured by transmission electron microscopy (TEM)-energy dispersive X-ray spectrometer (EDS), and the arithmetic mean of the measured values ​​was calculated to obtain A value, B value, C value and D value.

[0205] (Table 1)

[0206]

[0207] (Table 2)

[0208]

[0209] Examples 2 to 7 and Comparative Examples 1 to 5

[0210] The multilayer capacitors according to Examples 2 to 7 and Comparative Examples 1 to 5 were manufactured by weighing In so that the content of In within the multilayer capacitor could be the number of moles described in Table 3 below, and adjusting the oxygen partial pressure conditions.

[0211] (Evaluation example)

[0212] Evaluation Example 1: Measurement of Mean Time to Failure (MTTF)

[0213] Mean time to failure (MTTF) values ​​of the multilayer capacitors manufactured in Examples 1 to 7 and Comparative Examples 1 to 5 were measured by performing a high temperature load test under the conditions of 125° C. and 8V.

[0214] At this time, the time when the insulation resistance becomes less than or equal to 10 kΩ is set as a fixed time, the MTTF value of Comparative Example 1 is set as reference value 1, and relative values ​​of other examples and Comparative Examples are measured. The results are shown in Table 3 below.

[0215] Evaluation Example 2: Electrostatic Capacitance

[0216] The electrostatic capacitances of the multilayer capacitors manufactured in Examples 1 to 7 and Comparative Examples 1 to 5 were measured under the conditions of 1 kHz and AC 0.5 V by using an LCR meter.

[0217] The electrostatic capacitance of Comparative Example 1 was used as Reference Value 1, and relative values ​​of other Examples and Comparative Examples were measured, and the results are shown in Table 3 below.

[0218] (Table 3)

[0219]

[0220]

[0221] Referring to Table 3, it can be confirmed that in the case of the multilayer capacitors according to Examples 1 to 7, the MTTF and capacitance of the capacitors are excellent compared to Comparative Example 1 in which In is not contained in the multilayer capacitor. In addition, it can be confirmed that in the case of Comparative Examples 2 to 4 in which the In content in the multilayer capacitor is low, the capacitance value of the capacitor is lower than or similar to the capacitance value of Comparative Example 1.

[0222] Furthermore, it was confirmed that in the case of Comparative Example 5 in which the In content in the multilayer capacitor was excessively large, the MTTF and capacitance of the capacitor were both lower than those of Comparative Example 1.

[0223] While the present disclosure has been described in conjunction with what are presently considered to be practical example embodiments, it is to be understood that the present disclosure is not limited to the disclosed embodiments. Rather, the present disclosure is intended to cover various modifications and equivalents included within the spirit and scope of the appended claims.

Claims

1. A multilayer capacitor comprising: a capacitor body including a dielectric layer and inner electrodes; as well as An external electrode, disposed outside the capacitor body, wherein the capacitor body comprises Ti and In, and In the entire capacitor body, the content of In is 0.2 mol to 4 mol based on 100 mol of Ti.

2. The multilayer capacitor according to claim 1, wherein The dielectric layer includes a main component including a barium titanate-based compound and a subcomponent including In.

3. The multilayer capacitor according to claim 1, wherein The internal electrode includes In and a conductive metal other than In.

4. The multilayer capacitor of claim 1, wherein: The dielectric layer includes a central portion and an interface portion, the interface portion being located on a surface of the central portion and contacting the internal electrode, and When the molar content of In based on 100 mol of Ti in the interface portion is A and the molar content of In based on 100 mol of Ti in the central portion is B, A>B is satisfied.

5. The multilayer capacitor according to claim 4, wherein Satisfies A≥2B.

6. The multilayer capacitor according to claim 4, wherein A is 1.0 mol to 1.5 mol.

7. The multilayer capacitor according to claim 4, wherein B is 0.5 mol to 1.0 mol.

8. The multilayer capacitor of claim 1, wherein: The inner electrode includes a central portion and an interface portion, the interface portion being located on a surface of the central portion and contacting the dielectric layer, and When the molar content of In based on 100 mol of Ni in the interface portion is C and the molar content of In based on 100 mol of Ni in the central portion is D, C>D is satisfied.

9. The multilayer capacitor according to claim 8, wherein Satisfies C≥3D.

10. The multilayer capacitor according to claim 8, wherein C is 0.5 mol to 1.0 mol.

11. The multilayer capacitor according to claim 8, wherein D is 0.05 mol to 0.5 mol.

12. A multilayer capacitor comprising: a capacitor body including a dielectric layer and inner electrodes; as well as An external electrode, disposed outside the capacitor body, Wherein, the multilayer capacitor comprises Ti and In, Wherein, in the entire multilayer capacitor, the content of In is 0.2 mol to 4 mol based on 100 mol of Ti.

13. The multilayer capacitor of claim 12, wherein: The external electrode includes a sintered metal layer contacting the capacitor body, and The sintered metal layer includes In and a conductive metal other than In.

14. The multilayer capacitor of claim 12, wherein: The dielectric layer includes a central portion and an interface portion, the interface portion being located on a surface of the central portion and contacting the internal electrode, and When the molar content of In based on 100 mol of Ti in the interface portion is A and the molar content of In based on 100 mol of Ti in the central portion is B, A>B is satisfied.

15. The multilayer capacitor according to claim 14, wherein Satisfies A≥2B.

16. The multilayer capacitor according to claim 14, wherein A is 1.0 mol to 1.5 mol.

17. The multilayer capacitor according to claim 14, wherein B is 0.5 mol to 1.0 mol.

18. The multilayer capacitor of claim 12, wherein: The inner electrode includes a central portion and an interface portion, the interface portion being located on a surface of the central portion and contacting the dielectric layer, and When the molar content of In based on 100 mol of Ni in the interface portion is C and the molar content of In based on 100 mol of Ni in the central portion is D, C>D is satisfied.

19. The multilayer capacitor according to claim 18, wherein Satisfies C≥3D.

20. The multilayer capacitor of claim 18, wherein: C is 0.5 mol to 1.0 mol.

21. The multilayer capacitor of claim 18, wherein: D is 0.05 mol to 0.5 mol.

22. A multilayer capacitor comprising: A capacitor body including an inner electrode and a dielectric layer, wherein the inner electrode includes In and the dielectric layer includes Ti and In; as well as An external electrode, disposed outside the capacitor body, wherein, in the entire capacitor body, the content of In is 0.2 mol to 4 mol based on 100 mol of Ti, and Wherein, In exists at the interface between the dielectric layer and the inner electrode.

23. The multilayer capacitor according to claim 22, wherein: The dielectric layer includes a main component including a barium titanate-based compound.

24. The multilayer capacitor according to claim 23, wherein The inner electrode further includes a conductive metal other than In.

25. The multilayer capacitor of claim 24, wherein: The conductive metal includes Ni.

26. The multilayer capacitor of claim 25, wherein: The barium titanate-based compound includes barium titanate.

27. A multilayer capacitor comprising: a capacitor body including a dielectric layer and inner electrodes; as well as An external electrode, disposed outside the capacitor body, Wherein, the capacitor body comprises Ti and In, Wherein, in the entire capacitor body, the content of In is 0.2 mol to 4 mol based on 100 mol of Ti, The dielectric layer includes a central portion and an interface portion, the interface portion being located on a surface of the central portion and contacting the internal electrode, When the molar content of In based on 100 mol of Ti in the interface portion is A and the molar content of In based on 100 mol of Ti in the central portion is B, A>B is satisfied, The inner electrode includes a central portion and an interface portion, the interface portion of the inner electrode being located on a surface of the central portion of the inner electrode and contacting the dielectric layer, and When the molar content of In based on 100 moles of Ni in the interface portion of the inner electrode is C and the molar content of In based on 100 moles of Ni in the central portion of the inner electrode is D, C>D is satisfied.

28. The multilayer capacitor of claim 27, wherein: A≥2B and C≥3D are satisfied.

29. The multilayer capacitor of claim 27, wherein: A is 1.0 mol to 1.5 mol, B is 0.5 mol to 1.0 mol, C is 0.5 mol to 1.0 mol, and D is 0.05 mol to 0.5 mol.

30. The multilayer capacitor of claim 29, wherein: The dielectric layer includes a main component including a barium titanate-based compound and a subcomponent including In.

31. The multilayer capacitor of claim 30, wherein: The internal electrode includes In and a conductive metal other than In.

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