Multilayer ceramic capacitor and method for manufacturing the same

Abstract

This invention provides a multilayer ceramic capacitor with improved reliability and stability, and a method for manufacturing the same. [Solution] A multilayer ceramic capacitor according to an example of the present disclosure includes a capacitor body comprising a dielectric layer and an internal electrode layer, and an external electrode located outside the capacitor body, wherein the dielectric layer comprises glass having a secondary phase comprising Ga and Li.

Description

[Technical Field]

[0001] This disclosure relates to a multilayer ceramic capacitor and a method for manufacturing the same. [Background technology]

[0002] Electronic components that use ceramic materials include capacitors, inductors, piezoelectric elements, varistors, and thermistors. Among these ceramic electronic components, multilayer ceramic capacitors (MLCCs) can be used in a wide variety of electronic devices due to their advantages of being small, yet guaranteeing high capacitance and being easy to mount.

[0003] For example, multilayer ceramic capacitors (MLCCs) can be used as chip-type capacitors mounted on substrates of various electronic products such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic light-emitting diodes (OLEDs), computers, personal portable devices, and smartphones, playing a role in charging or discharging electricity.

[0004] Recently, as multilayer ceramic capacitors have been used in a variety of fields such as IT and automotive electronics, there is a growing demand for features such as robust temperature characteristics. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] According to one aspect of this disclosure, it is possible to provide a multilayer ceramic capacitor with improved reliability and stability.

[0006] According to another aspect of this disclosure, a method for manufacturing a multilayer ceramic capacitor with improved reliability and stability can be provided.

[0007] However, the problems that the embodiments of this disclosure aim to solve are not limited to those described above, and can be extended in various ways within the scope of the technical ideas contained in this disclosure. [Means for solving the problem]

[0008] A multilayer ceramic capacitor according to one embodiment includes a capacitor body comprising a dielectric layer and an internal electrode layer, and an external electrode located outside the capacitor body, wherein the dielectric layer comprises glass having a secondary phase comprising Ga and Li.

[0009] The secondary phase may include compound forms in which Ga and Li are bonded.

[0010] The glass may further contain at least one auxiliary element selected from the group consisting of Al, Mg, and Si.

[0011] The secondary phase may include a form in which the auxiliary elements are bonded together with Ga and Li.

[0012] The ratio of the signal intensity of Li to the signal intensity of Ga, measured by transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDS) on the aforementioned glass (I Li / I Ga ) may be between 0.1 and 3.

[0013] The dielectric layer may include a plurality of the glass, and the average particle size of the glass may be 100 nm to 500 nm.

[0014] The dielectric layer may include a plurality of the glass particles, and the maximum particle size of the glass particles may be less than 1 μm.

[0015] The secondary phase may originate from a complex compound containing Ga and Li.

[0016] The dielectric layer may further contain a barium titanate-based main component.

[0017] The glass is provided as a sub-component of the dielectric layer.

[0018] According to a method for manufacturing a multilayer ceramic capacitor according to another embodiment, a sub-component containing a complex compound containing Ga and Li, and a barium titanate-based main component powder are mixed to produce a dielectric slurry. A dielectric green sheet is produced using the dielectric slurry, and a conductive paste layer is formed on the dielectric green sheet. The dielectric green sheets are laminated to produce a dielectric green sheet laminate. The dielectric green sheet laminate is fired to produce a capacitor body including a dielectric layer and an internal electrode layer. An external electrode is formed on the capacitor body. The dielectric layer contains a glass having a secondary phase containing Ga and Li.

[0019] The complex compound can be contained in a liquid state.

[0020] The molar ratio of Ga contained in the complex compound may be 0.1 to 9 molar parts with respect to 100 molar parts of the barium titanate-based main component powder.

[0021] The molar ratio (M Li / M Ga ) of Li contained in the complex compound to the molar number of Ga contained in the complex compound may be 1 to 3.

[0022] The sub-component may further contain at least one selected from the group consisting of an Al-containing compound, a Mg-containing compound, and a Si-containing compound.

[0023] A multilayer ceramic capacitor according to another embodiment includes a capacitor body including a dielectric layer and an internal electrode layer, and an external electrode located outside the capacitor body, and the dielectric layer contains a glass having Ga and Li.

[0024] The glass may further contain at least one auxiliary element selected from the group consisting of Al, Mg, and Si.

[0025] The ratio of the signal intensity of Li to the signal intensity of Ga, measured by transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDS) on the aforementioned glass (I Li / I Ga ) may be between 0.1 and 3.

[0026] The dielectric layer may include a plurality of the glass, and the average particle size of the glass may be 100 nm to 500 nm. [Effects of the Invention]

[0027] According to one example of this disclosure, the dielectric layer contains a glass having a secondary phase in which Ga and Li are combined, thereby suppressing the volatilization of highly volatile Li. As a result, the firing temperature of the dielectric layer is reduced through Li, while the density is improved, thereby improving the capacitance characteristics, stability, and moisture resistance reliability of the multilayer ceramic capacitor. [Brief explanation of the drawing]

[0028] [Figure 1] This is a perspective view conceptually illustrating a multilayer ceramic capacitor as an example. [Figure 2] Figure 1 shows a conceptual cross-sectional view of a multilayer ceramic capacitor cut along the line I-I'. [Figure 3] This is a conceptual cross-sectional view of a multilayer ceramic capacitor cut along the line II-II' in Figure 1. [Figure 4]These are high-angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM) analysis images and mapping images of cross-sections of dielectric samples according to the examples. [Figure 5] This is a transmission electron microscope-electron energy loss spectroscopy (TEM-EELS) graph of a cross-section of a dielectric sample according to the example. [Figure 6] This is a particle size distribution diagram of glass measured in the cross-section of a dielectric sample according to the example. [Figure 7] This is a scanning electron microscope (SEM) analysis image of a cross-section of a dielectric sample according to the example. [Figure 8] This is an SEM analysis image of the cross-section of a dielectric sample in a comparative example. [Figure 9] This graph shows the density change of dielectric samples with respect to firing temperature in the examples and comparative examples. [Figure 10] This graph shows the change in dielectric constant of dielectric samples with respect to firing temperature in the examples and comparative examples. [Figure 11] This graph shows the changes in the content of Li, Ga, and Al in dielectric samples from the examples, depending on the firing temperature. [Figure 12] This graph shows the changes in the Li / Al atomic ratio and Li / Ga atomic ratio of dielectric samples according to the examples, depending on the firing temperature. [Figure 13] This is a conceptual schematic diagram illustrating a helium (He) gas permeability detector used to measure the density of dielectric materials. [Figure 14] This graph shows the analysis results of dielectric samples using a He gas permeability analyzer in the examples and comparative examples. [Figure 15] This graph shows the results of the moisture resistance reliability evaluation of multilayer ceramic capacitors based on the examples. [Figure 16] This graph shows the results of the humidity resistance reliability evaluation of multilayer ceramic capacitors using comparative examples. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described in detail below with reference to the attached drawings so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. In order to clearly illustrate the present invention, unnecessary parts have been omitted from the drawings, and the same or similar components are denoted by the same reference numerals throughout the specification. Furthermore, some components in the attached drawings are exaggerated, omitted, or shown schematically, and the size of each component does not fully reflect its actual size.

[0030] The accompanying drawings are provided solely to facilitate understanding of the embodiments disclosed herein, and it should be understood that the accompanying drawings do not limit the technical ideas disclosed herein and include all modifications, equivalents, or substitutions that fall within the concept and scope of the invention.

[0031] Terms including ordinal numbers, such as "first," "second," etc., are used to describe a variety of components, but the components are not limited by such terms. The terms are used solely for the purpose of distinguishing one component from another.

[0032] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on top of" or "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, being "on top of" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on top of" or "above" the opposite side of gravity.

[0033] Throughout the specification, terms such as “includes” or “have” are intended to specify the presence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preemptively exclude the presence or possibility of adding one or more other features, figures, stages, operations, components, parts, or combinations thereof. Therefore, when a part “includes” a component, this means that it may include other components rather than excluding them, unless otherwise stated.

[0034] Furthermore, throughout the specification, "on a plane" refers to the view of the subject from above, and "on a cross-section" refers to the view of a cross-section obtained by cutting the subject perpendicularly, viewed from the side.

[0035] Furthermore, throughout the specification, the term "connected" does not only mean that two or more components are directly connected, but can also mean that two or more components are indirectly connected through other components, that they are not only physically connected but also electrically connected, or that they are a single unit despite being referred to by different names depending on their location or function.

[0036] In the following, a multilayer ceramic capacitor according to an example of this disclosure will be described with reference to Figures 1 to 3.

[0037] Figure 1 is a conceptual perspective view showing an example of a multilayer ceramic capacitor. Figure 2 is a conceptual cross-sectional view of the multilayer ceramic capacitor cut along the line I-I' in Figure 1. Figure 3 is a conceptual cross-sectional view of the multilayer ceramic capacitor cut along the line II-II' in Figure 1.

[0038] Referring to Figures 1 to 3, the multilayer ceramic capacitor 100 can include a capacitor body 110 and external electrodes 131 and 132 positioned outside the capacitor body 110. The external electrodes 131 and 132 can include a first external electrode 131 and a second external electrode 132 positioned at opposite ends of the capacitor body 110 in the longitudinal direction (L-axis direction).

[0039] The L-axis, W-axis, and T-axis shown in Figures 1 to 3 represent the length, width, and thickness directions of the capacitor body 110, respectively. Here, the thickness direction (T-axis direction) may be perpendicular to the broad surface (main surface) of the sheet-shaped component, and can be used as the same concept as the stacking direction in which the dielectric layer 111 is stacked, for example. The length direction (L-axis direction) extends parallel to the broad surface (main surface) of the sheet-shaped component and may be roughly perpendicular to the thickness direction (T-axis direction), for example, 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) extends parallel to the broad surface (main surface) of the sheet-shaped component and may be roughly perpendicular to the thickness direction (T-axis direction) and the length direction (L-axis direction), and the length in the length direction (L-axis direction) of the sheet-shaped component may be even greater than the length in the width direction (W-axis direction).

[0040] In one example, the capacitor body 110 may have a substantially hexahedral shape.

[0041] For the sake of explanation, in the following, we define the two surfaces of the capacitor body 110 that face each other in the thickness direction (T-axis direction) as the first and second surfaces, the two surfaces connected to the first and second surfaces that face each other in the length direction (L-axis direction) as the third and fourth surfaces, and the two surfaces connected to the first and second surfaces that face each other in the width direction (W-axis direction) as the fifth and sixth surfaces.

[0042] The first surface, which is the lower surface of the capacitor body 110, may be the surface facing the mounting direction of the multilayer ceramic capacitor 100. At least one of the first to sixth surfaces may be flat. Alternatively, at least one of the first to sixth surfaces may be a curved surface with a convex central portion, and the corners that form the boundaries of each surface may be rounded.

[0043] The shape, dimensions, and number of dielectric layers 111 of the capacitor body 110 are not limited to those shown in the drawings of this disclosure.

[0044] The capacitor body 110 may include a dielectric layer 111 and internal electrode layers 121, 122. The capacitor body 110 may include multiple dielectric layers 111.

[0045] The capacitor body 110 may include a plurality of dielectric layers 111, and first internal electrode layers 121 and second internal electrode layers 122 that are alternately arranged in the thickness direction (T-axis direction) with the dielectric layers 111 in between.

[0046] The boundaries between adjacent dielectric layers 111 can become so integrated that they are difficult to detect without using a scanning electron microscope (SEM).

[0047] The capacitor body 110 may include an active region. The active region may be a part that contributes to the capacitance formation of the multilayer ceramic capacitor 100. For example, the active region may be an overlapping region of the first internal electrode layer 121 or the second internal electrode layer 122, which are stacked along the thickness direction (T-axis direction).

[0048] The capacitor body 110 may further include a cover area and a side margin area.

[0049] The cover region is a thickness-direction margin and can be arranged adjacent to the first and second surfaces of the active region in the thickness direction (T-axis direction). For example, a single dielectric layer 111 or two or more dielectric layers 111 are laminated on the upper and lower surfaces of the active region to provide the cover region.

[0050] The side margin region is a widthwise margin portion and can be positioned adjacent to the fifth and sixth surfaces of the active region in the widthwise direction (W-axis direction). The side margin region can be formed by laminating dielectric green sheets in which a conductive paste layer is applied only to a portion of the dielectric green sheet surface, and dielectric green sheets without a conductive paste layer applied to both side surfaces of the dielectric green sheet surface, and then firing them.

[0051] For example, damage to the first internal electrode 121 and the second internal electrode 122 due to physical or chemical stress can be prevented through the cover region and the side margin region.

[0052] The dielectric layer 111 may contain a barium titanate-based compound as its main component. For example, the dielectric properties of the multilayer ceramic capacitor 100 can be ensured by using the barium titanate-based compound as the dielectric base material.

[0053] The aforementioned barium titanate-based compounds may include BaTiO3, BaZrO3, BaSnO3, CaTiO3, CaZrO3, CaSnO3, SrTiO3, SrZrO3, SrSnO3, and the like. These can be used individually or in combination of two or more.

[0054] For example, the dielectric layer 111 may include glass having a secondary phase containing gallium (Ga) and lithium (Li). Ga and Li do not exist individually within the dielectric layer 111 but rather in a combined secondary phase form, which can suppress the volatilization of highly volatile Li. This allows for a reduction in the firing temperature of the dielectric layer 111 through Li, while simultaneously improving density, thereby improving the capacitance characteristics, stability, and moisture resistance reliability of the multilayer ceramic capacitor 100.

[0055] The glass can be provided as a minor component of the dielectric layer 111.

[0056] The aforementioned minor components may include manganese (Mn), chromium (Cr), silicon (Si), aluminum (Al), magnesium (Mg), tin (Sn), antimony (Sb), germanium (Ge), gallium (Ga), indium (In), barium (Ba), lanthanum (La), yttrium (Y), actinium (Ac), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), hafnium (Hf), vanadium (V), and others. These can be used individually or in combination of two or more.

[0057] As used herein, the term "secondary phase" can refer to a new phase deposited after firing of the dielectric layer 111 or the capacitor body 110. For example, when firing a dielectric green sheet laminate containing a barium titanate-based main component and minor components (e.g., the glass), elements such as Ga and Li are not dissolved in the barium titanate lattice but are deposited in the form of a secondary phase.

[0058] The secondary phase may include a compound in which Ga and Li are bonded. As an example, a compound in which Ga and Li are chemically bonded is provided as the secondary phase. This allows Ga to bond with Li, suppressing the volatilization of Li. This allows the firing temperature of the dielectric layer 111 to be reduced.

[0059] For example, the secondary phase may be derived from a complex compound containing Ga and Li. The complex compound is introduced in liquid form to form a liquid glass precursor, and the liquid glass precursor is calcined to form the aforementioned glass.

[0060] For example, the glass may further contain at least one auxiliary element selected from the group consisting of Al, Mg, and Si. The secondary phase can be formed by combining the auxiliary element with Ga and Li. For example, the secondary phase may include a form in which the auxiliary element is bonded with Ga and Li.

[0061] The presence of the secondary phase and the components contained in the secondary phase can be confirmed through high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) analysis, energy dispersive X-ray spectroscopy (EDS) mapping analysis, and transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS) analysis.

[0062] The multilayer ceramic capacitor 100 is fixed with an epoxy resin, and polished with a polishing machine so that a cross-section (L-T cross-section) cut perpendicularly to the length direction (L-axis direction) and the stacking direction (T-axis direction) in the width direction from the center in the width direction (W-axis direction) of the multilayer ceramic capacitor 100 is exposed. The polishing is performed so that half of the length in the width direction (W-axis direction) is removed. A HAADF-STEM analysis image is obtained for the dielectric layer 111 of the active region in the exposed L-T cross-section. The HAADF-STEM analysis can be performed using Tecnai Osiris 200 kV of FEI (USA) for a square region with a horizontal length of 10 μm and a vertical length of 10 μm. EDS mapping analysis is performed on the obtained HAADF-STEM analysis image to obtain a mapping image in which specific elements (for example, Ga, Mg, Al, etc.) are visually distinguished. For the region where Ga exists in the mapping image in which Ga is displayed as being distinguished in the mapping image, transmission electron microscope - electron energy loss spectroscopy (TEM-Electron Energy Loss Spectroscopy, TEM-EELS) can be performed. The TEM-EELS analysis can be performed using JEM-ARM200F (TEM) of JEOL and GIF Quantum (EELS) of Gatan for a square region with a horizontal length of 10 μm and a vertical length of 10 μm. Through the TEM-EELS analysis, the presence or absence of Li can be grasped within the region where Ga exists. Thereby, the presence and constituent components of the glass having a secondary phase containing Ga and Li can be confirmed.

[0063] The ratio (I Ga ) of the signal intensity (I Li ) of Li to the signal intensity (I Li ) of Ga measured by performing transmission electron microscope - energy dispersive X-ray spectroscopy (TEM-EDS) on the glass (I Ga) may be 0.1 to 3. Within this range, sufficient Li bonded to Ga remains in the dielectric layer 111, further reducing the firing temperature of the dielectric layer 111 and further improving its density.

[0064] For example, the dielectric layer 111 may include multiple of the aforementioned glass elements.

[0065] The average particle size of the glass may be between 100 nm and 500 nm. Within this range, over-aggregation of the glass is suppressed, and the low-temperature sintering characteristics and density of the dielectric layer 111 can be further improved. The average particle size may also be the average of the long axis lengths of each glass element.

[0066] The maximum particle size of the glass may be less than 1 μm. This further improves the dispersibility of the glass and increases its density.

[0067] The grain size of the glass can be measured from the mapping image described above. As an example, the active region of the LT cross section can be divided into three equal parts in the thickness direction, and the mapping image can be obtained at three points (a total of nine points) in each of the upper, middle, and lower active regions. The length of the major axis of each glass particle observed from the entire mapping image can be measured, and the average grain size can be determined by averaging these lengths. The largest value among the length of the major axis of the glass particles observed in the mapping image can be evaluated as the maximum grain size.

[0068] For example, the average thickness (average length in the T-axis direction) of the dielectric layer 111 may be approximately 1.0 μm to 8.0 μm. In another example, the average thickness (average length in the T-axis direction) of the dielectric layer 111 may be 2 μm to 6 μm. Within this range, the reliability of the multilayer ceramic capacitor 100 can be further improved.

[0069] The average thickness of the dielectric layer 111 can be measured by performing SEM analysis on a cross-section (LT cross-section) obtained by cutting the multilayer ceramic capacitor 100 perpendicular to the width direction in the length direction (L-axis direction) and the stacking direction (T-axis direction) from the center in the width direction (W-axis direction). The average thickness of the dielectric layer 111 can be determined by using the center point in the length direction (L-axis direction) or width direction (W-axis direction) of the dielectric layer 111 as a reference point in the SEM analysis image, and taking the arithmetic mean of the dielectric layer 111 thickness measured at 10 points separated by a predetermined interval from the reference point. The interval of the 10 points can be adjusted by the scale of the scanning electron microscope (SEM) image, for example, the interval may be 1 μm to 100 μm, 1 μm to 50 μm, or 1 μm to 10 μm. In this case, all 10 points must be located within the dielectric layer 111, and 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.

[0070] The first internal electrode 121 and the second internal electrode 122 of the internal electrode layers 121 and 122 can have different polarities. For example, the first internal electrode 121 and the second internal electrode 122 can be arranged alternately so as to face each other along the T-axis direction with the dielectric layer 111 in between. For example, one end of the first internal electrode 121 is exposed through the third surface of the capacitor body 110, and one end of the second internal electrode 122 is exposed through the fourth surface of the capacitor body 110.

[0071] The first internal electrode 121 and the second internal electrode 122 are electrically insulated by a dielectric layer 111 placed between them.

[0072] The end of the first internal electrode 121, exposed through the third surface of the capacitor body 110, can be electrically connected to the first external electrode 131. For example, the end of the second internal electrode 122, exposed through the fourth surface of the capacitor body 110, can be electrically connected to the second external electrode 132.

[0073] The first internal electrode 121 and the second internal electrode 122 may each include a conductive metal. For example, the conductive metal may include metals such as Ni, Cu, Ag, Pd, Au, Al, Zr, or alloys thereof (e.g., Ag-Pd alloy).

[0074] The first internal electrode 121 and the second internal electrode 122 may also contain dielectric particles of the same composition as the ceramic material contained in the dielectric layer 111.

[0075] The first internal electrode 121 and the second internal electrode 122 can be formed using a conductive paste containing a conductive metal. The method for printing the conductive paste can include screen printing or gravure printing.

[0076] The average thickness of the first internal electrode 121 and the second internal electrode 122 may be 0.1 μm to 2 μm. The average thickness of the first internal electrode 121 and the second internal electrode 122 can be measured by scanning electron microscopy (SEM) analysis. Here, the explanation of scanning electron microscopy (SEM) analysis is the same as the method used to measure the average thickness of the dielectric layer 111 described above, so it will be omitted.

[0077] The capacitor body 110 can be formed by firing a laminate in which multiple dielectric layers 111 and internal electrode layers 121 and 122 are stacked.

[0078] Referring to Figure 2, the first external electrode 131 and the second external electrode 132 can have different polarities from each other.

[0079] The first external electrode 131 is electrically connected to the portion of the first internal electrode 121 that is exposed. For example, the second external electrode 132 is electrically connected to the portion of the second internal electrode 122 that is exposed.

[0080] When a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charge accumulates between the opposing first internal electrode 121 and the second internal electrode 122. The capacitance of the multilayer ceramic capacitor 100 may be proportional to the overlapping area on the plane of the first internal electrode 121 and the second internal electrode 122, which overlap each other in the stacking direction (T-axis direction) in the active region.

[0081] The first external electrode 131 and the second external electrode 132 may include first and second connection portions (not shown) which are arranged on the third and fourth surfaces of the capacitor body 110, respectively, and connected to the first internal electrode 121 and the second internal electrode 122, respectively. The first external electrode 131 and the second external electrode 132 may each include first and second band portions (not shown) which are arranged at the corners where the third and fourth surfaces, the first and second surfaces, or the fifth and sixth surfaces of the capacitor body 110 meet.

[0082] The first band portion and the second band portion extend from the first and second connection portions to a portion of the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110, respectively. The fixing strength of the first external electrode 131 and the second external electrode 132 can be improved through the first and second band portions.

[0083] The first external electrode 131 and the second external electrode 132 may each include a sintered metal layer in contact with the capacitor body 110, a conductive resin layer disposed to cover the sintered metal layer, and a plating layer disposed to cover the conductive resin layer.

[0084] The sintered metal layer may include conductive metal and glass.

[0085] The conductive metal may include copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), lead (Pb), alloys thereof, or combinations thereof. For example, copper (Cu) may include copper (Cu) alloys. If the conductive metal includes copper, the other metals are included in an amount of 5 moles or less per 100 moles of copper.

[0086] The glass may contain a composition of mixed oxides, and may include, for example, at least one selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide.

[0087] Transition metals may include at least one selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni). Alkali metals may include at least one selected from the group consisting of lithium (Li), sodium (Na), and potassium (K). Alkaline earth metals may include at least one selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

[0088] Selectively, the conductive resin layer is formed on the sintered metal layer, for example, in a form that completely covers the sintered metal layer. For example, the first external electrode 131 and the second external electrode 132 do not have to include the sintered metal layer, in which case the conductive resin layer can be in direct contact with the capacitor body 110.

[0089] The conductive resin layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110, and the length of the region where the conductive resin layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 (i.e., the band portion) may be greater than the length of the region where the sintered metal layer extends to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 (i.e., the band portion). For example, the conductive resin layer can be formed on top of the sintered metal layer and can completely cover the sintered metal layer.

[0090] The conductive resin layer comprises a resin and a conductive metal.

[0091] The resin contained in the conductive resin layer is not particularly limited as long as it has bonding and shock-absorbing properties and can be mixed with conductive metal powder to form a paste, and may include, for example, phenolic resin, acrylic resin, silicone resin, epoxy resin, or polyimide resin.

[0092] The conductive metal contained in the conductive resin layer may be spherical, flake-shaped, or a combination thereof. For example, the conductive metal may consist only of flake-shaped metal, only of spherical metal, or a mixture of flake-shaped and spherical metal.

[0093] Here, spherical can include forms that are not perfectly spherical, for example, forms in which the ratio of the length of the major axis to the length of the minor axis (major axis / minor axis) is 1.45 or less. Flake powder means powder having a flat and elongated shape, and is not particularly limited, but for example, the ratio of the length of the major axis to the length of the minor axis (major axis / minor axis) may be 1.95 or more.

[0094] The first external electrode 131 and the second external electrode 132 may further include a plating layer disposed on the outside of the conductive resin layer.

[0095] The plating layer may include nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), or lead (Pb), either alone or in alloys thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, or it may be a configuration in which a nickel (Ni) plating layer and a tin (Sn) plating layer are sequentially laminated, or it may be a configuration in which a tin (Sn) plating layer, a nickel (Ni) plating layer, and a tin (Sn) plating layer are sequentially laminated. Furthermore, the plating layer may include multiple nickel (Ni) plating layers and / or multiple tin (Sn) plating layers.

[0096] The aforementioned plating layer improves the mountability, structural reliability, external durability, and heat resistance of the multilayer ceramic capacitor 100 on the substrate, and further reduces the equivalent series resistance (ESR).

[0097] The following describes a method for manufacturing a multilayer ceramic capacitor 100 as an example.

[0098] A method for manufacturing a multilayer ceramic capacitor 100 may include the steps of manufacturing a capacitor body 110 including a dielectric layer 111 and internal electrodes 121 and 122, and forming external electrodes 131 and 132 on the outside of the capacitor body 110.

[0099] For example, a calcined powder can be obtained by mixing and heat-treating a barium titanate (BaTiO3)-based main component powder and a secondary component containing a complex compound with Ga and Li. A dielectric slurry can be produced by adding an organic vehicle or an aqueous vehicle to the calcined powder, heating and mixing it.

[0100] The barium titanate-based main component powder is a compound containing barium (Ba) and titanium (Ti), and may include, for example, BaTiO3, Ba(Ti,Zr)O3, Ba(Ti,Sn)O3, (Ba,Ca)TiO3, (Ba,Ca)(Ti,Ca)O3, (Ba,Ca)(Ti,Zr)O3, (Ba,Ca)(Ti,Sn)O3, (Ba,Sr)TiO3, (Ba,Sr)(Ti,Zr)O3, (Ba,Sr)(Ti,Sn)O3, or combinations thereof.

[0101] The complex compound can be provided in liquid form. For example, the complex compound can be provided as a Ga-Li liquid glass precursor containing Ga and Li. This suppresses the volatilization of Li during firing and further improves the dispersibility of the glass having a secondary phase containing Ga and Li within the dielectric layer 111.

[0102] The complex compound may further contain ligands such as organic substances, in which case Ga and Li may be provided as complex ions. The organic substances and / or ligands can be selected without limitation as long as they can bond with Ga and Li.

[0103] For example, the molar ratio of Ga contained in the complex compound may be 0.1 to 9 moles per 100 moles of the barium titanate-based main component powder. Within this range, Ga combines with Li, further suppressing the volatilization of Li. This further improves the density and glass dispersibility of the dielectric layer 111.

[0104] The molar ratio (M) of Li contained in the complex compound to the number of moles of Ga contained in the complex compound. Li / M Ga ) may be 1 to 3. Within this range, a sufficient secondary phase containing Ga and Li is formed, further suppressing the volatilization of Li. This can further increase the density and dielectric constant of the dielectric layer 111 and further decrease its porosity.

[0105] The content of Ga, Li, and other elements contained in the barium titanate-based main component powder and the complex compound can be measured using inductively coupled plasma-optical emission spectroscopy (ICP-OES). For example, the content of Ga, Li, and other elements contained in the barium titanate-based main component powder and the complex compound can be measured using PerkinElmer's Avio500 instrument.

[0106] The aforementioned auxiliary component may further include at least one selected from the group consisting of Al-containing compounds, Mg-containing compounds, and Si-containing compounds. The Al-containing compound, Mg-containing compound, and Si-containing compound may each be an oxide, nitride, or salt compound, or they may be used in sol form dispersed in an organic solvent.

[0107] The dielectric slurry can be manufactured by further mixing in additives such as dispersants, binders, plasticizers, lubricants, and antistatic agents with a solvent.

[0108] The dispersant may include a phosphate ester-based dispersant, a polycarboxylic acid-based dispersant, or a combination thereof. The dispersant can be mixed in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the barium titanate compound, for example, 0.3 to 3 parts by weight. When the dispersant is mixed within the above content range, the dispersibility of the dielectric slurry is further improved, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0109] The binder may include acrylic resin, polyvinyl butyl resin, polyvinyl acetal resin, ethyl cellulose resin, and the like. The binder can be added in an amount of 0.1 to 50 parts by weight per 100 parts by weight of the barium titanate compound, for example, 3 to 30 parts by weight. When the binder is mixed within the above content range, the dispersibility of the dielectric slurry is further improved, and the amount of impurities contained in the manufactured dielectric layer can be further reduced.

[0110] The plasticizer may include phthalate compounds such as dioctyl phthalate, benzyl butyl phthalate, dibutyl phthalate, dihexyl phthalate, di(2-ethylhexyl) phthalate, and di(2-ethylbutyl) phthalate; adipic acid compounds such as dihexyl adipic acid and di(2-ethylhexyl) adipic acid; glycol compounds such as ethylene glycol, diethylene glycol, and triethylene glycol; and glycol ester compounds such as triethylene glycol dibutyrate, triethylene glycol di(2-ethylbutyrate), and triethylene glycol di(2-ethylhexanoate). The plasticizer can be added in an amount of 0.1 to 20 parts by weight per 100 parts by weight of the barium titanate compound, for example, 1 to 10 parts by weight. When the plasticizer is mixed within the above content range, the dispersibility of the dielectric slurry is further improved, and the amount of impurities contained in the manufactured dielectric layer can be reduced.

[0111] The solvent may be an aqueous solvent such as water; an alcoholic solvent such as ethanol, methanol, benzyl alcohol, or methoxyethanol; a glycolic solvent such as ethylene glycol or diethylene glycol; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone; an esteric solvent such as butyl acetate, ethyl acetate, carbitol acetate, or butyl carbitol acetate; an etheric solvent such as methyl cellosolve, ethyl cellosolve, butyl ether, or tetrahydrofuran; or an aromatic solvent such as benzene, toluene, or xylene. The solvent may include an alcoholic solvent or an aromatic solvent, for example, considering the solubility and dispersibility of various additives contained in the dielectric slurry. The solvent can be mixed in an amount of 50 to 1000 parts by weight per 100 parts by weight of the barium titanate compound, for example, 100 to 500 parts by weight. When the solvent is mixed within the above content range, the dielectric slurry components can be thoroughly mixed, and the solvent can then be easily removed.

[0112] The dielectric slurry can be mixed using a wet ball mill or a stirring mill. When using zirconia balls in a wet ball mill, a large number of zirconia balls with diameters from 0.1 mm to 10 mm can be used for wet mixing for 8 to 48 hours, or 10 to 24 hours.

[0113] The manufactured dielectric slurry is formed as a dielectric layer 111 after firing.

[0114] Methods for forming the manufactured dielectric slurry into a sheet shape include tape forming methods such as the doctor blade method and the calender roll method, and for example, an on-roll molding coater with a head discharge type can be used. A dielectric green sheet can then be obtained by drying the molded body.

[0115] To form the conductive paste layer that will become the internal electrode layers 121 and 122 after firing, a conductive paste can be manufactured by mixing conductive powder made of a conductive metal or an alloy thereof, a binder, and a solvent. Additionally, barium titanate powder can be mixed in as a co-material if necessary. The co-material can suppress the sintering of the conductive powder during the firing process. The conductive paste layer can be formed by applying the conductive paste in a predetermined pattern to the surface of a dielectric green sheet using various printing methods such as screen printing or transfer methods.

[0116] The conductive powder may include nickel (Ni) or a nickel (Ni) alloy.

[0117] Next, a dielectric green sheet laminate can be manufactured by laminating multiple dielectric green sheets with internal electrode patterns in a layered manner and then applying pressure in the lamination direction. Dielectric green sheets and internal electrode patterns can be laminated such that dielectric green sheets are positioned on the upper and lower surfaces of the dielectric green sheet laminate in the lamination direction.

[0118] The manufactured dielectric green sheet laminate can be selectively cut to predetermined dimensions by dicing or other methods.

[0119] The dielectric green sheet laminate can be solidified and dried to remove plasticizers and other substances as needed, and after solidification and drying, it can be barrel polished using a horizontal centrifugal barrel polishing machine or the like. In barrel polishing, the dielectric green sheet laminate is placed in a barrel container along with media and polishing fluid, and rotational motion or vibration is applied to the barrel container to polish away unwanted parts such as burrs generated during cutting. After barrel polishing, the dielectric green sheet laminate is washed with a cleaning solution such as water and dried.

[0120] The dielectric green sheet laminate can be subjected to a binder removal process and a firing process to obtain the capacitor body 110.

[0121] The conditions for the binder removal process can be appropriately adjusted depending on the main component composition of the dielectric layer and the main component composition of the internal electrodes. For example, the heating rate during the binder removal process may be 5°C / hour to 300°C / hour, the support temperature may be 180°C to 400°C, and the temperature maintenance time may be 0.5 hours to 24 hours. The binder removal atmosphere may be air or a reducing atmosphere.

[0122] The firing conditions can be appropriately adjusted depending on the main component composition of the dielectric layer and the main component composition of the internal electrodes. For example, the firing temperature may be 1200°C to 1350°C or 1220°C to 1300°C, and the firing 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, a humidified atmosphere of a mixed gas of nitrogen gas (N2) and hydrogen gas (H2). If the internal electrodes 121 and 122 contain nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere should be 1.0 × 10⁻⁶. -14 MPa ~ 1.0 × 10 -10 MPa is also acceptable.

[0123] After the firing process, annealing can be performed as needed. This annealing process is for re-oxidizing the dielectric layer and can be performed when the firing process is carried out in a reducing atmosphere. The conditions for the annealing process can also be appropriately adjusted depending on the main component composition of the dielectric layer. For example, the annealing temperature may be 950°C to 1150°C, the duration may be 0 to 20 hours, and the heating rate may be 50°C / hour to 500°C / hour. The annealing atmosphere may be a humidified nitrogen gas (N2) atmosphere, and the oxygen partial pressure may be 1.0 × 10⁻⁶. -9 MPa ~ 1.0 × 10 -5 MPa is also acceptable.

[0124] For debinding, calcination, or annealing processes, a wetter, for example, can be used to humidify nitrogen gas or a mixed gas, in which case the water temperature may be between 5°C and 75°C. Debinding, calcination, and annealing processes can be performed continuously or independently.

[0125] Selectively, surface treatments such as sandblasting, laser irradiation, or barrel polishing can be performed on the third and fourth surfaces of the obtained capacitor body 110. Through such surface treatments, the ends of the first internal electrode 121 and the second internal electrode 122 are exposed on the outermost surfaces of the third and fourth surfaces. This improves the electrical connection between the first external electrode 131 and the second external electrode 132 and the first internal electrode 121 and the second internal electrode 122, and facilitates the formation of the alloy portion.

[0126] External electrodes 131 and 132 can be formed on one surface of the manufactured capacitor body 110.

[0127] For example, a sintered metal layer can be formed by applying a paste for forming a sintered metal layer and then sintering it.

[0128] The paste for forming a sintered metal layer may contain the aforementioned conductive metals and glass. Furthermore, the paste for forming a sintered metal layer may selectively contain a binder, solvent, dispersant, plasticizer, oxide powder, etc. The binder may include, for example, ethyl cellulose, acrylic, butyral, and the solvent may include, for example, organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, or aqueous solvents.

[0129] As a method for applying the sintered metal layer forming paste to the outer surface of the capacitor body 110, various printing methods such as dipping and screen printing, application methods using dispensers, and spraying methods using sprays can be used.

[0130] The sintered metal layer forming paste is applied to at least the third and fourth surfaces of the capacitor body 110, and can also be applied to a portion of the first, second, fifth, or sixth surfaces where the band portions of the first and second external electrodes are selectively formed.

[0131] Subsequently, the capacitor body 110 coated with the paste for forming the sintered metal layer is dried, and the sintered metal layer can be formed by sintering it at a temperature of 700°C to 1000°C for 0.1 to 3 hours.

[0132] Selectively, a conductive resin layer can be formed on the outer surface of the obtained capacitor body 110 by applying a paste for forming a conductive resin layer and then curing it.

[0133] The paste for forming a conductive resin layer may contain a resin and, selectively, a conductive metal or a non-conductive filler. The descriptions of conductive metals and resins are the same as those given above, so repeated explanations will be omitted. The paste for forming a conductive resin layer may also selectively contain a binder, solvent, dispersant, plasticizer, oxide powder, etc. The binder may be, for example, ethyl cellulose, acrylic, butyral, etc., and the solvent may be an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, or an aqueous solvent.

[0134] As an example, the conductive resin layer can be formed by dipping the capacitor body 110 into a conductive resin layer forming paste and then curing it, or by printing the conductive resin layer forming paste onto the surface of the capacitor body 110 using a screen printing method or gravure printing method, or by applying the conductive resin layer forming paste to the surface of the capacitor body 110 and then curing it.

[0135] A plating layer can be formed on the outside of the conductive resin layer.

[0136] For example, the plating layer can be formed by a plating method, and can also be formed by sputtering or electroplating (electric deposition).

[0137] The following provides specific examples of the present disclosure. However, the examples described below are for illustrative or illustrative purposes only. [Examples]

[0138] [Examples] (Manufacturing of dielectric samples) A dielectric slurry was prepared by adding and mixing 100 moles of barium titanate (BaTiO3) powder as the main component, and Ga-Li liquid complex compound, MgCO3, Al2O3, and SiO2 as minor components in amounts of 2.2 moles, 0.467 moles, 0.12 moles, and 1.38 moles, respectively, to ethanol solvent per 100 moles of barium titanate. Specifically, a dielectric slurry was prepared by mixing 12 kg of barium titanate and approximately 500 g of the aforementioned minor components in 40 kg of ethanol solvent.

[0139] In the Ga-Li liquid complex compound, the ratio of moles of Ga to moles of Li was adjusted to 1:3.

[0140] The aforementioned mixing was carried out by mechanical milling after adding ethanol / toluene, a wetting dispersant, and polyvinyl butyral (PVB) resin as a binder, using zirconia balls (ZrO2 balls) as the dispersion medium.

[0141] Dielectric green sheets were manufactured using a head-dispensing type on-roll molding coater with the manufactured dielectric slurry.

[0142] A dielectric green sheet laminate was manufactured by laminating and pressing the dielectric green sheets together.

[0143] The dielectric green sheet laminate was cut to a predetermined size and fired at 1075°C to produce a dielectric sample.

[0144] (Manufacturing of multilayer ceramic capacitors) A dielectric green sheet was manufactured, similar to the dielectric sample mentioned earlier.

[0145] A dielectric green sheet laminate was manufactured by printing a conductive paste layer containing Ni on the surface of the dielectric green sheet, and then laminating and pressing the dielectric green sheets on which the conductive paste layer was formed.

[0146] The dielectric green sheet laminate was calcined at a temperature of 400°C or lower and in a nitrogen atmosphere, maintaining the calcination temperature at 1210°C and a hydrogen concentration of 0.11% for 51 seconds.

[0147] Next, the multilayer ceramic capacitor was manufactured through processes such as the addition of external electrodes and plating.

[0148] [Comparative Example] A dielectric slurry was prepared by adding and mixing 100 moles of barium titanate (BaTiO3) powder as the main component, and MgCO3, Al2O3, and SiO2 as minor components in amounts of 0.467 moles, 0.12 moles, and 1.38 moles, respectively, to 100 moles of barium titanate in an ethanol solvent.

[0149] Dielectric samples and multilayer ceramic capacitors were manufactured in the same manner as in the examples, except that the dielectric slurry described above was used.

[0150] [Evaluation 1: HAADF-STEM, EDS mapping, and TEM-EELS analysis] Figure 4 shows HAADF-STEM analysis images (Figure 4(a)) and mapping images (Figures 4(b), (c), and (d)) of the cross-section of a dielectric sample according to the example.

[0151] Referring to Figure 4, HAADF-STEM analysis images were obtained for cross-sections (LT sections) cut perpendicular to the width direction in the length direction and stacking direction from the center of the width direction of the dielectric samples manufactured by the examples and comparative examples (Figure 4(a)). The HAADF-STEM analysis was performed on a square region of 10 μm horizontally and 10 μm vertically using a Tecnai Osiris 200kV from FEI (USA).

[0152] EDS mapping analysis was performed on the obtained HAADF-STEM analysis images to obtain mapping images in which the glass containing Mg, Al, and Ga was visually distinguished (Figures 4(b), (c), and (d)).

[0153] Figure 5 is a TEM-EELS graph of the LT cross-section of the dielectric sample according to the example. Figure 5(a) is a mapping image showing the glass containing Ga as in Figure 4(d). Figure 5(b) is a TEM-EELS analysis graph of the first and second square regions of Figure 5(a). The TEM-EELS analysis was performed on regions with dimensions of 10 μm horizontally and 10 μm vertically using JEOL's JEM-ARM200F (TEM) and Gatan's GIF Quantum (EELS).

[0154] Referring to Figure 5, the TEM-EELS analysis revealed a Li peak within the secondary phase region where Ga is present, confirming the existence of a glass having a secondary phase containing Ga and Li.

[0155] TEM-EDS analysis was performed on the first and second square regions in Figure 5(a), and the peak intensities of the elements contained in each region were measured. The measurement results are shown in Table 1 below. In Table 1, the peak intensity of the element measured in the first square region is shown as "E1", and the peak intensity of the element measured in the second square region is shown as "E2". In Table 1, the peak intensity of each element in the first square region is divided by the peak intensity of Ga and shown as "1 / Ga", and the peak intensity of each element in the second square region is divided by the peak intensity of Ga and shown as "2 / Ga".

[0156] [Table 1]

[0157] Referring to Table 1 above, the ratio of the signal intensity of Li to the signal intensity of Ga in the first and second square regions of Figure 5(a) is (I Li / I GaThe values ​​were measured at 0.45 and 0.48, respectively.

[0158] [Evaluation 2: Measurement of average and maximum particle size of glass] Figure 6 shows the particle size distribution of glass measured at the LT cross-section of the dielectric sample according to the example.

[0159] Figure 6(a) is a mapping image showing glass containing Ga, as in Figure 4(d). Figure 6(b) is a grain size distribution diagram of the glass observed in Figure 6(a).

[0160] Referring to Figure 6, the major axis length (grain size) of each glass element observed in the mapping image of the cross-section of the dielectric sample manufactured according to the embodiment was measured and shown in the grain size distribution diagram.

[0161] The average of the aforementioned particle sizes was evaluated as the average particle size. In the example, the average particle size (Avg in Figure 6) was measured to be 262.4 nm, which was relatively small. In addition, the maximum particle size of the glass in the example (Max in Figure 6) was measured to be approximately 432.01 nm. Therefore, the formation of glass aggregates with particle sizes of 1 μm or larger was sufficiently suppressed.

[0162] [Evaluation 3: Porosity measurement of dielectric samples] Figure 7 shows an SEM analysis image of the LT cross-section of the dielectric sample according to the embodiment.

[0163] SEM analysis can be performed using a Zeiss GeminiSEM300 (electron gun type) for areas of approximately 30 μm horizontally and vertically.

[0164] Referring to Figures 7 and 8, SEM analysis images were obtained for the LT cross-sections of dielectric samples manufactured according to the examples and comparative examples, respectively, and the number of pores and porosity were measured from the SEM analysis images.

[0165] The SEM analysis image of the example showed 96 pores and a porosity of 0.2125. The SEM analysis image of the comparative example showed 1481 pores and a porosity of 3.1228.

[0166] Referring to Figures 7 and 8, the example containing a glass with a secondary phase including Ga and Li showed a relative decrease in the number of pores and porosity compared to the comparative example. As a result, the density of the dielectric sample in the example was improved compared to the dielectric sample in the comparative example.

[0167] The number of pores and porosity of the examples and comparative examples were measured using MiDAS (Microstructure Image Database and Analysis System) 2.3.

[0168] [Evaluation 4: Measurement of density and dielectric constant of dielectric samples] Figure 9 is a graph showing the density change of dielectric samples with respect to firing temperature for the examples and comparative examples. Figure 10 is a graph showing the dielectric constant change of dielectric samples with respect to firing temperature for the examples and comparative examples.

[0169] The density and dielectric constant of dielectric samples from the examples and comparative examples were measured while varying the firing temperature from 1000°C to 1100°C.

[0170] The volume of the dielectric sample was calculated by measuring its length, width, and thickness, and its density was calculated by measuring its weight. The dielectric constant was measured according to ASTM D150-98.

[0171] Referring to Figures 9 and 10, the dielectric samples of the examples were measured to have higher density and dielectric constant at relatively lower temperatures than the dielectric samples of the comparative examples. Therefore, the density and capacitance characteristics of the dielectric samples of the examples were relatively improved compared to the comparative examples.

[0172] [Evaluation 5: Component analysis of dielectric samples based on firing temperature] Figure 11 is a graph showing the changes in the content of Li, Ga, and Al of dielectric samples according to the examples, depending on the firing temperature. Figure 12 is a graph showing the changes in the Li / Al atomic ratio and Li / Ga atomic ratio of dielectric samples according to the examples, depending on the firing temperature.

[0173] The content (moles) of Li, Al, and Ga elements per 100 moles of barium titanate main component powder was measured while varying the firing temperature of the dielectric samples in the examples from 1000°C to 1100°C and is shown in Figure 11. The molar ratios of Li to Al and Li to Ga are shown in Figure 12.

[0174] The content of each element was measured using inductively coupled plasma-mass spectrometry (ICP-MS). Specifically, the content of each element was measured using PerkinElmer's NexION 300S at different firing temperatures of dielectric samples.

[0175] [Evaluation 6: Analysis of Ga and Li volatility] During the production of dielectric samples, the molar ratio of Ga and Li in the Ga-Li liquid complex compound was adjusted as shown in Table 2 below, and the dielectric samples according to the reference example were produced by firing at the same temperature as in the examples.

[0176] The residual amounts of Li and Ga in the dielectric sample after firing were measured using PerkinElmer's NexION 300S, and the volatilization rate due to firing was calculated. The residual amounts represent the molar amounts of Li and Ga per 100 molar parts of barium titanate (BT) main component powder after firing.

[0177] The aforementioned volatility rate was calculated by dividing the difference between the input amount and the remaining amount by the input amount and multiplying by 100.

[0178] Table 2 shows the amounts of Li and Ga added per 100 moles of barium titanate (BT) main component powder. In Table 2, "-" indicates a trace amount that is not detected.

[0179] [Table 2]

[0180] As shown in Table 2 above, in Reference Examples 7-9, where the amount of Ga added was less than 0.1 moles per 100 moles of barium titanate main component powder, Li and Ga were substantially completely evaporated.

[0181] The molar ratio of the amount of Li added to the amount of Ga added (M Li / M Ga In Reference Examples 1-3, where the ratio is 1-3, the volatilization of Li was relatively suppressed compared to Reference Examples 4-9. This reduces the particle size of the glass and improves dispersibility.

[0182] [Evaluation 7: Density analysis of dielectric samples] Dielectric samples prepared according to the examples and comparative examples were placed in a helium (He) gas permeation analyzer (Agilent GC / MS, 5977B), and the pressure of the He gas permeating through the dielectric samples was measured. Figure 13 is a conceptual schematic diagram illustrating the helium (He) gas permeation analyzer used to measure the density of dielectric samples.

[0183] Figure 14 is a graph showing the analysis results of dielectric samples using a He gas permeability analyzer for the examples and comparative examples.

[0184] Referring to Figure 14, the density of the dielectric sample in the example was relatively higher than that of the dielectric sample in the comparative example, and the pressure of the permeated He gas was measured to be lower in the example than in the comparative example.

[0185] [Evaluation 8: Characteristic Analysis of Multilayer Ceramic Capacitors] (Cp, DF, and BDV analysis) The capacitance (Cp), dissipation factor (DF), and breakdown voltage (BDV) were measured for the multilayer ceramic capacitors manufactured according to the examples and comparative examples.

[0186] Specifically, capacitance and loss coefficient were measured using an Agilent capacitance meter (model: 4268A). Dielectric breakdown voltage was measured using a Keithley high-resistance / low-current potentiometer (model: 6430).

[0187] (Moisture resistance reliability analysis) The humidity resistance reliability of the multilayer ceramic capacitors manufactured according to the examples and comparative examples was evaluated by measuring the change in internal resistance (IR) for 12 hours under conditions of 85°C, 85% relative humidity, and 15.75V using an ESPEC PR-3J 8585 apparatus.

[0188] Figure 15 is a graph showing the results of the humidity resistance reliability evaluation of a multilayer ceramic capacitor according to the example. Figure 16 is a graph showing the results of the humidity resistance reliability evaluation of a multilayer ceramic capacitor according to the comparative example.

[0189] Referring to Figures 15 and 16, in the example, the IR over time was maintained relatively stably compared to the comparative example. Therefore, the moisture resistance reliability was improved in the example compared to the comparative example.

[0190] The measurement results are shown in Table 3 below. The failure rate in Table 3 represents the percentage of multilayer ceramic capacitors that failed (inability to maintain IR) when the moisture resistance reliability evaluation described above was performed on multiple multilayer ceramic capacitors.

[0191] [Table 3]

[0192] As shown in Table 3 above, the examples including glass having a secondary phase containing Ga and Li showed relatively improved capacitance characteristics, low resistance characteristics, dielectric breakdown voltage, and drive reliability compared to the comparative examples. [Explanation of symbols]

[0193] 100: Multilayer ceramic capacitor 110: Capacitor body 111: Dielectric layer 121: 1st internal electrode 122:Second internal electrode 131: 1st external electrode 132:Second external electrode

Claims

1. A capacitor body including a dielectric layer and an internal electrode layer, The capacitor body includes an external electrode located on the outside, A multilayer ceramic capacitor comprising a dielectric layer containing glass having a secondary phase containing Ga and Li.

2. The multilayer ceramic capacitor according to claim 1, wherein the secondary phase includes a compound form in which Ga and Li are bonded.

3. The multilayer ceramic capacitor according to claim 1, wherein the glass further comprises at least one auxiliary element selected from the group consisting of Al, Mg, and Si.

4. The multilayer ceramic capacitor according to claim 3, wherein the secondary phase includes a form in which the auxiliary elements are bonded together with Ga and Li.

5. The ratio of the signal intensity of Li to the signal intensity of Ga, measured by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS) on the glass (I Ｌｉ / I Ｇａ The multilayer ceramic capacitor according to claim 1, wherein the coefficient of the coefficient is 0.1 or more and 3 or less.

6. The multilayer ceramic capacitor according to claim 1, wherein the dielectric layer comprises a plurality of the glass, and the average particle size of the glass is 100 nm or more and 500 nm or less.

7. The multilayer ceramic capacitor according to claim 1, wherein the dielectric layer comprises a plurality of the glass, and the maximum particle size of the glass is less than 1 μm.

8. The multilayer ceramic capacitor according to claim 1, wherein the secondary phase is derived from a complex compound containing Ga and Li.

9. The multilayer ceramic capacitor according to claim 1, wherein the dielectric layer further comprises a barium titanate-based main component.

10. The multilayer ceramic capacitor according to claim 9, wherein the glass is provided as a minor component of the dielectric layer.

11. A step of preparing a dielectric slurry by mixing a secondary component containing a complex compound containing Ga and Li, and a barium titanate-based main component powder, The steps include: manufacturing a dielectric green sheet using the dielectric slurry and forming a conductive paste layer on the dielectric green sheet; The steps include: manufacturing a dielectric green sheet laminate by stacking the dielectric green sheets; The steps include: firing the dielectric green sheet laminate to manufacture a capacitor body including a dielectric layer and an internal electrode layer; The step of forming an external electrode on the capacitor body is included, A method for manufacturing a multilayer ceramic capacitor, wherein the dielectric layer includes glass having a secondary phase containing Ga and Li.

12. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the complex compound is contained in liquid form.

13. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the molar ratio of Ga contained in the complex compound is 0.1 moles or more and 9 moles or less per 100 moles of the barium titanate-based main component powder.

14. The molar ratio (M) of Li contained in the complex compound to the number of moles of Ga contained in the complex compound. Ｌｉ / M Ｇａ The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein ) is 1 or more and 3 or less.

15. The method for manufacturing a multilayer ceramic capacitor according to claim 11, wherein the aforementioned minor component further comprises at least one selected from the group consisting of Al-containing compounds, Mg-containing compounds, and Si-containing compounds.

16. A capacitor body including a dielectric layer and an internal electrode layer, The capacitor body includes an external electrode located on the outside, The dielectric layer comprises glass containing Ga and Li, and is a multilayer ceramic capacitor.

17. The multilayer ceramic capacitor according to claim 16, wherein the glass further comprises at least one auxiliary element selected from the group consisting of Al, Mg, and Si.

18. The ratio of the signal intensity of Li to the signal intensity of Ga, measured by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS) on the glass (I Ｌｉ / I Ｇａ The multilayer ceramic capacitor according to claim 16, wherein the coefficient of the coefficient is 0.1 or more and 3 or less.

19. The multilayer ceramic capacitor according to claim 16, wherein the dielectric layer comprises a plurality of the glass, and the average particle size of the glass is 100 nm or more and 500 nm or less.

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