Multilayer ceramic capacitor and method for manufacturing the same

Abstract

To provide multilayer ceramic capacitors with improved reliability and low resistance characteristics. [Solution] A multilayer ceramic capacitor according to an example of the present disclosure includes a capacitor body comprising a dielectric layer 111 and an internal electrode 121, and an external electrode located outside the capacitor body and comprising Ni and an auxiliary element comprising at least one of Sn, Al, Zn, In, and Co, wherein the internal electrode includes a first interface region 123 in contact with the external electrode, and the first interface region comprises an alloy comprising both Ni and the auxiliary element.

Description

[Technical Field]

[0001] The disclosures of this application relate to multilayer ceramic capacitors and methods 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 can be used as chip-type capacitors mounted on the substrates of many electronic products such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic light-emitting diodes (OLEDs), computers, personal mobile devices, and smartphones, playing a role in charging or discharging electricity.

[0004] Recently, with the miniaturization of electronic products, there has been a demand for ultra-miniaturization and ultra-high capacitance in multilayer ceramic capacitors. To this end, multilayer ceramic capacitors are being manufactured with thinner dielectric layers and internal electrode layers, and a structure that stacks a greater number of dielectric and internal electrode layers. These ultra-miniaturized and ultra-high capacitance multilayer ceramic capacitors are now being used in fields requiring high levels of reliability, such as electric vehicles, and therefore demand high stability and reliability to meet these requirements. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] According to one aspect of this disclosure, it is possible to provide multilayer ceramic capacitors with improved reliability and low resistance characteristics.

[0006] According to another aspect of this disclosure, a method for manufacturing multilayer ceramic capacitors with improved reliability and low-resistance characteristics can be provided.

[0007] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0008] In one embodiment, the multilayer ceramic capacitor includes a capacitor body comprising a dielectric layer and internal electrodes; and external electrodes located outside the capacitor body and comprising Ni and an auxiliary element comprising at least one of Sn, Al, Zn, In, and Co; wherein the internal electrodes include a first interface region in contact with the external electrodes, and the first interface region comprises an alloy comprising both Ni and the auxiliary element.

[0009] The first interface region can be defined as a region where the content of the auxiliary element, measured by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) along the direction from the interface between the internal electrode and the external electrode toward the interior of the internal electrode, is 5 mol% or more of the total amount of Ni and the auxiliary element.

[0010] The external electrode includes an electrode layer electrically connected to the internal electrode, and the electrode layer may include Ni and the auxiliary element.

[0011] The electrode layer includes a second interface region in contact with the internal electrode, and the second interface region may include an alloy of Ni and the auxiliary element.

[0012] The second interface region can be defined as a region where the content of the auxiliary elements, measured by SEM-EDS along the direction from the interface between the electrode layer and the internal electrode toward the interior of the electrode layer, is 5 mol% to 20 mol% of the total amount of Ni and the auxiliary elements.

[0013] The first interface region and the second interface region can be connected.

[0014] The electrode layer does not necessarily have to contain Cu.

[0015] The amount of Ni in the total amount of Ni and auxiliary elements contained in the external electrode may be 80 mol% to 95 mol%.

[0016] The content of the auxiliary element in the total amount of Ni and the auxiliary element contained in the external electrode can be 5 mol% to 20 mol%.

[0017] The Ni contained in the external electrode may be in the form of Ni metal.

[0018] The internal electrode contains Ni, and the internal electrode and the external electrode can be electrically connected through the alloy.

[0019] The external electrode may further include glass.

[0020] The glass content may be 1 to 40 parts by weight per 100 parts by weight of the total amount of Ni and the auxiliary elements contained in the external electrode.

[0021] The external electrode comprises a plurality of Ni metals and a plurality of the auxiliary elements, and the average particle size of the Ni metals and the average particle size of the auxiliary elements contained in the external electrode can be 0.05 μm to 10 μm, respectively.

[0022] According to the manufacturing method of a multilayer ceramic capacitor according to an embodiment, an electrode layer forming paste is applied to one surface of a capacitor body including a dielectric layer and an internal electrode, and the electrode layer forming paste is sintered to form an electrode layer of an external electrode. The electrode layer forming paste contains Ni and an auxiliary element including at least one of Sn, Al, Zn, In, and Co, the internal electrode includes a first interface region in contact with the external electrode, and the first interface region can include an alloy of Ni and the auxiliary element.

[0023] The sintering can be performed at 500°C to 850°C.

[0024] The electrode layer includes a second interface region in contact with the internal electrode, and the second interface region can include an alloy of Ni and the auxiliary element.

[0025] The content of Ni in the total amount of Ni and the auxiliary element contained in the electrode layer forming paste can be 80 mol% to 95 mol%.

[0026] The content of the auxiliary element in the total amount of Ni and the auxiliary element contained in the electrode layer forming paste can be 5 mol% to 20 mol%.

Advantages of the Invention

[0027] According to an example of the present disclosure, the electrical connectivity between the external electrode and the internal electrode of the multilayer ceramic capacitor can be improved, and the capacitance characteristics and moisture resistance reliability can be enhanced.

[0028] According to an example of the present disclosure, cracks in the radial direction of the multilayer ceramic capacitor can be suppressed, and the structural stability and reliability can be enhanced.

Brief Description of the Drawings

[0029] [Figure 1] It is a perspective view showing a multilayer ceramic capacitor according to an example. [Figure 2]This is a cross-sectional view of a multilayer ceramic capacitor cut along the line I-I' in Figure 1. [Figure 3] This is a cross-sectional view of a multilayer ceramic capacitor cut along the line II-II' in Figure 1. [Figure 4] This is a magnified partial cross-sectional view of portion A in Figure 2. [Figure 5] This is a scanning electron microscopy (SEM) analysis image of a multilayer ceramic capacitor according to Example 7. [Figure 6] This is an SEM analysis image of a multilayer ceramic capacitor according to Comparative Example 7. [Figure 7] This graph shows the capacitances of the multilayer ceramic capacitors produced in Example 7 and Comparative Example 7. [Modes for carrying out the invention]

[0030] 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 the drawings, unnecessary parts have been omitted in order to clearly illustrate the present invention, and the same or similar components are denoted by the same reference numerals throughout the specification. In addition, 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.

[0031] The accompanying drawings are for the sole purpose of facilitating the understanding of the embodiments disclosed herein, and the accompanying drawings shall not limit the technical ideas disclosed herein, and shall be understood to include all modifications, equivalents, or substitutions that fall within the concept and scope of the invention.

[0032] Terms including ordinal numbers, such as "first," "second," etc., may be used to describe a variety of components, but the components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from another.

[0033] Furthermore, when a layer, membrane, region, plate, or other part is said to be "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when one part is said to be "directly above" another part, it means that there is no other part in between. Also, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" in the opposite direction of gravity.

[0034] Throughout the specification, terms such as “includes” or “having” are intended to indicate the presence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and should not be understood 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, unless otherwise stated, that it may include other components rather than excluding them.

[0035] 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.

[0036] Furthermore, throughout the specification, the term "connected" does not only mean that two or more components are directly connected, but may 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 based on their location or function.

[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 a multilayer ceramic capacitor cut along the line I-I' in Figure 1. Figure 3 is a conceptual cross-sectional view of a 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 stacking directions of the capacitor body 110, respectively. Here, the stacking direction (T-axis direction) is the direction perpendicular to the broad surface (main surface) of the sheet-shaped component, and can be used with the same concept as the direction in which the dielectric layer 111 is stacked, for example. The length direction (L-axis direction) is the direction extending parallel to the broad surface (main surface) of the sheet-shaped component, and is approximately perpendicular to the stacking direction (T-axis direction), and may be the direction in which the first external electrode 131 and the second external electrode 132 are located on both sides, for example. The width direction (W-axis direction) is the direction extending parallel to the broad surface (main surface) of the sheet-shaped component, and is approximately perpendicular to the stacking 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 longer than the length in the width direction (W-axis direction).

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

[0041] For the sake of explanation, in the capacitor body 110, the two surfaces facing each other in the stacking direction (T-axis direction) are defined as the first and second surfaces, the two surfaces connected to the first and second surfaces and facing each other in the length direction (L-axis direction) are defined as the third and fourth surfaces, and the two surfaces connected to the first and second surfaces and connected to the third and fourth surfaces and facing each other in the width direction (W-axis direction) are defined as the fifth and sixth surfaces.

[0042] The first surface, which is the lower surface of the capacitor body 110, can 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 electrodes 121 and 122. The capacitor body 110 may include multiple dielectric layers 111. The internal electrodes 121 and 122 may include a first internal electrode 121 and a second internal electrode 122 that are alternately and repeatedly arranged in the stacking direction (T-axis direction).

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

[0046] The boundaries between adjacent dielectric layers 111 can be so integrated that they are difficult to confirm 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 121 or the second internal electrode 122 stacked along the stacking direction (T-axis direction).

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

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

[0050] The side margin region can be positioned adjacent to the fifth and sixth surfaces of the active region in the width direction (W-axis direction), respectively, as a width-direction margin portion. 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 the conductive paste layer is not applied to the sides 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, by using the barium titanate-based compound as the dielectric base material, the dielectric properties of the multilayer ceramic capacitor 100 can be ensured.

[0053] The barium titanate-based compounds mentioned above 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] The dielectric layer 111 may further contain minor components.

[0055] 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 the like. These can be used individually or in combination of two or more.

[0056] In one 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.

[0057] For example, the average thickness of the dielectric layer 111 can be determined by the arithmetic mean of the dielectric layer 111 thickness measured at 10 points separated by a predetermined interval from the reference point, using a scanning electron microscope (SEM) analysis image of a cross-section (LT section) obtained by cutting the dielectric layer 111 perpendicular to the width direction (L-axis direction) at the center of the width direction (W-axis direction) of the multilayer ceramic capacitor 100 in the length direction (L-axis direction) and the stacking direction (T-axis direction). The interval of the 10 points can be adjusted by the scale of the SEM image, for example, between 1 μm and 100 μm, between 1 μm and 50 μm, or between 1 μm and 10 μm. In this case, all 10 points must be located within the dielectric layer 111. If all 10 points are not located within the dielectric layer 111, the position of the reference point can be changed or the interval of the 10 points can be adjusted.

[0058] The first internal electrode 121 and the second internal electrode 122 may have different polarities. For example, the first internal electrode 121 and the second internal electrode 122 may be arranged alternately facing each other along the T-axis direction with the dielectric layer 111 in between. For example, one end of the first internal electrode 121 may be exposed through the third surface of the capacitor body 110, and one end of the second internal electrode 122 may be exposed through the fourth surface of the capacitor body 110.

[0059] The first internal electrode 121 and the second internal electrode 122 can be electrically insulated by a dielectric layer 111 placed between them.

[0060] 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.

[0061] 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, or alloys thereof (e.g., Ag-Pd alloy).

[0062] 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.

[0063] The first internal electrode 121 and the second internal electrode 122 may be formed using a conductive paste containing a conductive metal. For example, the conductive paste may be printed by screen printing or gravure printing.

[0064] For example, the average thickness of the first internal electrode 121 and the second internal electrode 122 may be 0.1 μm to 2 μm. Within this range, miniaturization and thinning of the multilayer ceramic capacitor 100 can be achieved, thereby further reducing the resistance.

[0065] The average thickness of the first internal electrode 121 and the second internal electrode 122 can be measured by SEM analysis. The SEM analysis is substantially the same as the method for measuring the average thickness of the dielectric layer 111 described above.

[0066] The capacitor body 110 can be formed by firing a laminate in which multiple dielectric layers 111 and internal electrodes 121 and 122 are stacked.

[0067] Referring to Figure 2, the first external electrode 131 and the second external electrode 132 can have different polarities from each other.

[0068] The first external electrode 131 can be electrically connected to the portion of the first internal electrode 121 that is exposed. For example, the second external electrode 132 can be electrically connected to the portion of the second internal electrode 122 that is exposed.

[0069] When a predetermined voltage is applied to the first external electrode 131 and the second external electrode 132, charge can be accumulated between the opposing first internal electrode 121 and the second internal electrode 122. The capacitance of the multilayer ceramic capacitor 100 can 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.

[0070] The first external electrode 131 and the second external electrode 132 may include first and second connecting portions (not shown) which are located 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 also include first and second band portions (not shown) which are located 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.

[0071] The first and second band portions can extend to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 at the first and second connection portions, 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.

[0072] The external electrodes 131 and 132 may include electrode layers 10 and 20 located on the surface of the capacitor body 110.

[0073] The first external electrode 131 may include a first electrode layer 10 that is directly located on the surface of the capacitor body 110 (e.g., the third surface) and electrically connected to the first internal electrode 121. For example, the second external electrode 132 may include a second electrode layer 20 that is directly located on the surface of the capacitor body 110 (e.g., the fourth surface) and electrically connected to the second internal electrode 122.

[0074] Figure 4 is an enlarged partial cross-sectional view of portion A in Figure 2.

[0075] Referring to Figure 4, the external electrodes 131, 132 or electrode layers 10, 20 may include a conductive metal 11 and glass 12. In one example, the glass 12 may be dispersed within the conductive metal 11. The conductive metal 11 and glass 12 may be included in the electrode layers 10, 20.

[0076] The conductive metal 11 contains nickel (Ni) 11a and may contain auxiliary elements 11b, which include at least one of tin (Sn), aluminum (Al), zirconium (Zr), indium (In), and cobalt (Co). Ni may be provided as the main component of the conductive metal 11 and / or electrode layers 10, 20. This can suppress radial cracking of the multilayer ceramic capacitor 100 and improve structural stability and reliability.

[0077] In one example, multiple auxiliary elements 11b can be dispersed within the Ni main component 11a.

[0078] The Ni contained in the external electrodes 131 and 132 may be in the form of Ni metal. For example, the Ni contained in the external electrodes 131 and 132 does not necessarily have to contain secondary structures such as Ni oxide.

[0079] The electrode layers 10 and 20 do not necessarily have to contain copper (Cu). By using Ni instead of Cu as the main component of the electrode layers 10 and 20, damage to the multilayer ceramic capacitor 100 can be suppressed, and structural stability and reliability can be improved.

[0080] The glass 12 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.

[0081] 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).

[0082] The glass content can be 1 to 40 parts by weight per 100 parts by weight of the total amount of conductive metal 11 (Ni and auxiliary element 11b) contained in the external electrodes 131 and 132. Within this range, the density and stability of the external electrodes 131 and 132 can be further improved.

[0083] The aforementioned internal electrodes 121 and 122 may include a first interface region 123 that is in contact with the external electrodes 131 and 132.

[0084] The first interface region 123 may include an alloy of Ni and auxiliary element 11b. This improves the electrical connectivity between the external electrodes 131, 132 and the internal electrodes 121, 122, thereby improving the capacitance characteristics and reliability of the multilayer ceramic capacitor 100. The alloy may contain both Ni and auxiliary element 11b, or represent an alloy in which Ni and auxiliary element 11b are bonded. For example, the alloy may include a Ni-Sn alloy.

[0085] For example, the Ni in the alloy may come from the internal electrodes 121, 122 and / or the external electrodes 131, 132.

[0086] The internal electrodes 121, 122 and the external electrodes 131, 132 can be electrically connected through the alloy. For example, the Ni in the internal electrodes 121, 122 and the Ni in the external electrodes 131, 132 can be electrically connected through the alloy. During sintering, the auxiliary element 11b can form a eutectic point between Ni and the auxiliary element 11b at the boundary between the external electrodes 131, 132 and the internal electrodes 121, 122, thereby forming an alloy of Ni and the auxiliary element 11b. The connectivity between the external electrodes 131, 132 and the internal electrodes 121, 122 can be enhanced through the alloy, improving capacitance characteristics and moisture resistance reliability.

[0087] The first interface region 123 can be defined as a region where the content of auxiliary element 11b, measured by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) or transmission electron microscopy-EDS (TEM-EDS) along the direction from the interface between the internal electrodes 121, 122 and the external electrodes 131, 132 toward the interior of the internal electrodes 121, 122, is 5 mol% or more of the total amount of Ni and auxiliary element 11b. Alternatively, the first interface region 123 may be a region extending approximately 1 μm from the interface between the internal electrodes 121, 122 and the external electrodes 131, 132 toward the interior of the internal electrodes 121, 122.

[0088] The electrode layers 10 and 20 include a second interface region 13 that contacts the internal electrodes 121 and 122, and the second interface region 13 may contain the aforementioned alloy of Ni and auxiliary element 11b. This can further enhance the connectivity between the external electrodes 131 and 132 and the internal electrodes 121 and 122, thereby improving the capacitance characteristics of the multilayer ceramic capacitor 100.

[0089] The second interface region 13 can be defined as the region where the content of auxiliary element 11b, measured by SEM-EDS along the direction toward the interior of the electrode layers 10 and 20 from the interface between the electrode layers 10 and 20 and the internal electrodes 121 and 122, is 5 mol% to 20 mol% of the total amount of Ni and auxiliary element 11b. Alternatively, the second interface region 13 may be the region extending approximately 1 μm in the direction toward the interior of the electrode layers 10 and 20 from the interface between the electrode layers 10 and 20 and the internal electrodes 121 and 122.

[0090] The first interface region 123 and the second interface region 13 can be separated by a virtual line extending along the interface between the dielectric layer 111 and the electrode layers 10 and 20, or the interface between the capacitor body 110 and the external electrodes 131 and 132. For example, the virtual line can extend in the stacking direction (T-axis direction) along the interface between the dielectric layer 111 and the electrode layers 10 and 20. The first interface region 123 can be located on one side in the length direction (L-axis direction) relative to the virtual line, and the second interface region 13 can be located on the other side in the length direction (L-axis direction).

[0091] The first interface region 123 and the second interface region 13 can be connected. For example, the first interface region 123 and the second interface region 13 can be provided as a single, substantially integrated region. For instance, Ni and auxiliary element 11b form the alloy at a eutectic point by sintering, and the first interface region 123 and the second interface region 13 can be defined by the location of the alloy.

[0092] The presence / content of Ni, auxiliary elements 11b, and the alloy contained in the first interface region 123 and the second interface region 13 can be confirmed and measured by performing SEM analysis and EDS mapping 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) at the center in the width direction (W-axis direction) of the capacitor. The multilayer ceramic capacitor 100 can be fixed with epoxy resin and polished with a polishing machine so that the LT cross-section is exposed. The polishing can be performed so that half of the length in the width direction (W-axis direction) is removed. One to six rectangular regions of 40 μm horizontally and 40 μm vertically can be set on the exposed LT cross-section so that the internal electrodes 121, 122 and electrode layers 10, 20 are included, and SEM analysis images can be obtained for each of the rectangular regions. By performing EDS mapping and line scan / point scan on the aforementioned SEM analysis image, the region where Ni and auxiliary element 11b exist and the content of Ni and auxiliary element 11b can be measured. The region where Ni and auxiliary element 11b overlap at least partially can be evaluated as the region where the alloy exists. By averaging the SEM-EDS analysis results for the entire square region, information (location, content, etc.) about Ni, auxiliary element 11b, and the alloy can be obtained. Through the SEM-EDS analysis, the content of glass 12 relative to the total amount of conductive metal 11 can also be measured.

[0093] The Ni 11a content in the total amount of Ni 11a and auxiliary element 11b contained in the external electrodes 131 and 132 can be 80 mol% to 95 mol%. Within this range, the capacitance characteristics of the multilayer ceramic capacitor 100 are further improved, thereby further enhancing the coupling stability of the internal electrodes 121 and 122 and the external electrodes 131 and 132.

[0094] The content of auxiliary element 11b in the total amount of Ni 11a and auxiliary element 11b contained in the external electrodes 131 and 132 can be 5 mol% to 20 mol%. Within this range, the driving reliability of the multilayer ceramic capacitor 100 can be further improved, thereby suppressing the deterioration of capacitance characteristics.

[0095] In one example, the external electrodes 131 and 132 may contain multiple Ni metal particles and multiple auxiliary elements 11b. The average particle size of the Ni metal and auxiliary elements 11b contained in the external electrodes 131 and 132 may be 0.05 μm to 10 μm, respectively. Within this range, the density of the external electrodes 131 and 132 can be further improved, and the alloy of Ni and auxiliary elements can be formed more smoothly. The average particle size can be calculated by measuring the maximum long axis of at least 100 particles for each element in the SEM analysis image of the LT cross-section and creating a particle size distribution cumulative curve. The average particle size represents the particle size at the point where the particle size distribution cumulative curve reaches 50%. The average particle size may be referred to as D50.

[0096] For example, the external electrodes 131 and 132 may further include plating layers 30 and 40 located on the electrode layers 10 and 20.

[0097] The external electrodes 131 and 132 may selectively further include a conductive resin layer (not shown) located between the electrode layers 10 and 20 and the plating layers 30 and 40.

[0098] The conductive resin layer may extend to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110. In this case, the length of the region where the conductive resin layer is located (e.g., the band portion) may be longer than the length of the region where the electrode layers 10 and 20 extend to the first and second surfaces or the fifth and sixth surfaces of the capacitor body 110 (e.g., the band portion). For example, the conductive resin layer may completely cover the electrode layers 10 and 20.

[0099] The conductive resin layer may include a resin and a conductive member.

[0100] The resin is not particularly limited as long as it has bonding properties and shock absorption and can be mixed with conductive member powder to make a paste, and may include, for example, phenolic resin, acrylic resin, silicone resin, epoxy resin, or polyimide resin.

[0101] The conductive member can be electrically connected to the internal electrodes 121, 122 or the electrode layers 10, 20.

[0102] The conductive member may be spherical, flake-shaped, or a combination thereof. For example, the conductive member may consist solely of flakes, solely of spheres, or may include a mixture of flakes and spheres.

[0103] The aforementioned spherical shape may include forms that are not perfectly spherical, for example, a form in which the ratio of the length of the long axis to the short axis (long axis / short axis) is 1.45 or less. Flake-like powder refers to powder having a flat and elongated shape and is not particularly limited, but for example, the ratio of the length of the long axis to the short axis (long axis / short axis) may be 1.95 or more.

[0104] The external electrodes 131 and 132 may further include plating layers 30 and 40 that are arranged to cover the aforementioned conductive resin layer.

[0105] The plating layers 30 and 40 may include a first plating layer 30 disposed on the first electrode layer 10 and a second plating layer 40 disposed on the second electrode layer 20.

[0106] The plating layers 30 and 40 may include nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof. These can be used individually or in combination of two or more.

[0107] The plating layers 30 and 40 may be nickel (Ni) plating layers or tin (Sn) plating layers. For example, the plating layers 30 and 40 may include a configuration in which nickel (Ni) plating layers and tin (Sn) plating layers are sequentially laminated, or a configuration in which tin (Sn) plating layers, nickel (Ni) plating layers, and tin (Sn) plating layers are sequentially laminated. For example, the plating layers 30 and 40 may also include multiple nickel (Ni) plating layers and / or multiple tin (Sn) plating layers.

[0108] The plating layers 30 and 40 can improve the mountability of the multilayer ceramic capacitor 100 on the substrate, its structural reliability, its durability against external elements, its heat resistance, and its equivalent series resistance (ESR).

[0109] The following describes a method for manufacturing a multilayer ceramic capacitor 100 using other examples.

[0110] 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, 122; and forming external electrodes 131, 132 on the outside of the capacitor body 110.

[0111] In the manufacturing process of the capacitor body 110, a dielectric paste that will become the dielectric layer 111 after firing and a conductive paste that will become the internal electrodes 121 and 122 after firing can be prepared.

[0112] A dielectric powder can be uniformly mixed and dried through wet mixing or the like, and then heat-treated under predetermined conditions to obtain a calcined powder. The dielectric paste can be produced by adding an organic vehicle or an aqueous vehicle to the calcined powder, heating and mixing it.

[0113] A dielectric green sheet can be obtained by forming the dielectric paste into a sheet using a technique such as the doctor blade method. For example, the dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, minor component compounds, and / or glass.

[0114] Conductive paste for internal electrodes can be prepared by kneading conductive powder, which consists of a conductive metal or an alloy thereof, with a binder or solvent.

[0115] The conductive paste for the internal electrode may contain indium (In).

[0116] The conductive paste for the internal electrode may contain ceramic powder (for example, barium titanate powder) as a co-material. The co-material can suppress the sintering of the conductive powder during the firing process.

[0117] The conductive paste for the internal electrodes can be applied to the surface of a dielectric green sheet in a predetermined pattern using various printing methods such as screen printing or transfer methods. A dielectric green sheet laminate can be obtained by laminating multiple dielectric green sheets on which the internal electrode pattern is formed and applying pressure in the lamination direction. The dielectric green sheet and the internal electrode pattern can be laminated such that the dielectric green sheet is located on the upper and lower surfaces of the dielectric green sheet laminate in the lamination direction.

[0118] Selectively, the dielectric green sheet laminate can be cut to predetermined dimensions by dicing or the like.

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

[0120] The capacitor body 110 can be obtained by performing a binder removal process and a firing process on the dielectric green sheet laminate.

[0121] The conditions for the binder removal process can be appropriately adjusted by 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 holding temperature may be 180°C to 400°C, and the temperature holding time may be 0.5 hours to 24 hours. The binder removal atmosphere may be air or a reducing atmosphere.

[0122] The conditions for the firing 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 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 is a reducing atmosphere, and may be, 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 under the firing atmosphere is 1.0 × 10⁻⁶. -14 MPa ~ 1.0 × 10 -10 It could be in MPa.

[0123] After the firing process, annealing may be performed as needed. This annealing is a process to re-oxidize 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 0 to 20 hours, and the heating rate 50°C / hour to 500°C / hour. The annealing atmosphere is a humidified nitrogen gas (N2) atmosphere, and the oxygen partial pressure is 1.0 × 10⁻⁶. -9 MPa ~ 1.0 × 10 -5 It could be in MPa.

[0124] In debindering, calcining, 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. Debindering, calcining, 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 can be exposed on the 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 allows for the easy formation of an alloy portion.

[0126] External electrodes 131 and 132 can be manufactured by applying an electrode layer forming paste to the outer surface of the capacitor body 110 and sintering it to form electrode layers 10 and 20.

[0127] The electrode layer forming paste may include a conductive metal 11 and a glass composition. The glass 12 may be formed by firing the glass composition.

[0128] The conductive metal 11 may include Ni and an auxiliary element comprising at least one of Sn, Al, Zn, In, and Co. Sintering may form an alloy of the auxiliary element and Ni, thereby improving the connection between the internal electrodes 121, 122 and the external electrodes 131, 132.

[0129] The glass composition may include at least one selected from the group consisting of Si oxide, Al oxide, Fe oxide, Sn oxide, Zn oxide, Li oxide, Na oxide, K oxide, Ba oxide, Ca oxide, Sr oxide, B oxide, Ni oxide, Mn oxide, Ge oxide, Cu oxide, In oxide, Co oxide, Ti oxide, and P oxide.

[0130] For example, the glass composition may include Li2O, Na2O, K2O, SiO2, Al2O3, FeO, Fe2O3, Fe3O4, NiO, Ni2O3, Ni3O4, In2O3, TiO2, P2O5, BaO, CaO, SrO, B2O3, ZnO, SnO, SnO2, Cu2O, CuO, CoO, Co2O3, GeO2, MnO, Mn2O, Mn2O3, Mn3O4, etc. These can be used individually or in combination of two or more.

[0131] Glass 12 can be manufactured by mixing the components of a glass composition, heat-treating it at a certain temperature or higher, rapidly cooling it, and then atomizing it, or by using gas phase, liquid phase, or spray pyrolysis methods.

[0132] The electrode layer forming paste may further contain a binder, a solvent, a dispersant, a plasticizer, an oxide powder, and the like.

[0133] The binder may include, for example, ethylcellulose, acrylic, or butyral, and the solvent may include, for example, organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or aqueous solvents.

[0134] The Ni content in the electrode layer forming paste and the total amount of Ni in the auxiliary elements can be 80 mol% to 95 mol%. Within this range, the capacitance characteristics of the multilayer ceramic capacitor 100 are further improved, thereby further enhancing the coupling stability of the internal electrodes 121, 122 and the external electrodes 131, 132.

[0135] The content of the auxiliary elements in the total amount of Ni and the auxiliary elements contained in the electrode layer forming paste can be 5 mol% to 20 mol%. Within this range, the driving reliability of the multilayer ceramic capacitor 100 can be further improved, thereby suppressing the deterioration of capacitance characteristics.

[0136] As a method for applying the electrode 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. The electrode layer forming paste is applied to at least the third and fourth surfaces of the capacitor body 110, and may 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.

[0137] The sintering can be carried out at a temperature of 500°C to 850°C. Within this range, a sufficient alloy of Ni and auxiliary elements can be formed, and the bonding stability of the internal electrodes 121, 122 and the external electrodes 131, 132 can be further improved.

[0138] Next, a conductive resin layer-forming paste can be selectively applied to the outer surface of the capacitor body 110 on which the electrode layers 10 and 20 are formed, and then cured to form a conductive resin layer.

[0139] The conductive resin layer-forming paste may contain a resin and, selectively, a conductive metal or a non-conductive filler. The explanations regarding conductive metals and resins are the same as those given above, so redundant explanations will be omitted. The conductive resin layer-forming paste may also 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 organic solvents such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, toluene, or aqueous solvents.

[0140] As an example, the conductive resin layer may 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.

[0141] Plating layers 30 and 40 can be formed on the outside of the conductive resin layer.

[0142] The plating layers 30 and 40 can be formed by a plating method, and can also be formed by sputtering or electroplating (electric deposition).

[0143] The internal electrodes 121 and 122 of the multilayer ceramic capacitor 100 formed by the manufacturing method described above include a first interface region 123 that is in contact with the external electrodes 131 and 132, and the first interface region 123 may contain an alloy of Ni and the aforementioned auxiliary elements.

[0144] The electrode layers 10 and 20 include a second interface region 13 that is in contact with the internal electrodes 121 and 122, and the second interface region 13 may contain an alloy of Ni and the aforementioned auxiliary elements.

[0145] The following are specific examples of the present disclosure. However, the examples described below are for illustrative purposes only.

[0146] Examples 1 to 10 (Manufacturing of multilayer ceramic capacitors) After manufacturing dielectric green sheets using barium titanate (BaTiO3) as the main component powder, a conductive paste layer containing Ni was printed onto the surface of the dielectric green sheets. Dielectric green sheet laminates (width × length × height = 3.2 mm × 2.5 mm × 2.5 mm) with the conductive paste layer formed thereon were laminated and pressed together to manufacture dielectric green sheet laminates. Capacitor bodies were manufactured by firing the dielectric green sheet laminates at a temperature of 1300°C or less and a hydrogen concentration of 1.0%H2 or less in a calcination process at a nitrogen atmosphere at a temperature of 400°C or less.

[0147] An electrode layer forming paste was prepared by mixing and dispersing 65% by weight of Ni, 5% by weight of Sn, 10% by weight of glass composition, 15% by weight of binder, and 5% by weight of dispersant (total 100% by weight). The glass composition contains 9.0 mol% lithium oxide (Li2O), 10 mol% sodium oxide (Na2O), 1.5 mol% iron(III) oxide (Fe2O3), 6.3 mol% zinc oxide (ZnO), 21 mol% barium oxide (BaO), 11 mol% silicon dioxide (SiO2), 8 mol% calcium oxide (CaO), 12 mol% aluminum oxide (Al2O3), 20.2 mol% boron trioxide (B2O3), and 1 mol% tin(IV) oxide (SnO2) (total 100 mol%).

[0148] The electrode layer forming paste was applied to the outer surface of the capacitor body and dried, and then sintered at 400°C to 850°C as shown in Table 1 below to form the electrode layer of the external electrode. The sintering could be carried out in an N2 gas atmosphere or an N2 and H2 mixed gas atmosphere, and was carried out in an N2 gas atmosphere. Next, a Ni plating layer and a Sn plating layer were sequentially formed on the surface of the electrode layer to manufacture a multilayer ceramic capacitor.

[0149] Comparative Examples 1 to 10 The multilayer ceramic capacitors of Comparative Examples 1 to 10 were manufactured in the same manner as those of Examples 1 to 10, except that Sn was not added to the paste for forming the electrode layer.

[0150] Evaluation 1: SEM analysis The multilayer ceramic capacitors from Example 7 and Comparative Example 7 were placed horizontally and fixed around the perimeter with epoxy resin.

[0151] The multilayer ceramic capacitor was polished using a polishing machine so that the cross-section (LT cross-section) obtained by cutting perpendicular to the width direction (W-axis direction) in the length direction (L-axis direction) and the stacking direction (T-axis direction) at the center in the width direction (W-axis direction) of the aforementioned multilayer ceramic capacitor was exposed.

[0152] A rectangular region measuring 40 μm horizontally and 40 μm vertically was defined in the center of the exposed LT cross section in the stacking direction (T-axis direction), including the internal electrode layer and the electrode layer. SEM imaging was performed on this rectangular region. The SEM imaging was performed using a Thermofisher Scientific Verios G4 under an accelerating voltage of 200 kV.

[0153] Figure 5 shows an SEM analysis image of the multilayer ceramic capacitor according to Example 7. Figure 6 shows an SEM analysis image of the multilayer ceramic capacitor according to Comparative Example 7.

[0154] Referring to Figures 5 and 6, in Example 7, the disconnection between the internal and external electrodes was reduced compared to Comparative Example 7, which had the same sintering temperature, and the connectivity was improved.

[0155] Rating 2: Capacity Rating The capacitance of the multilayer ceramic capacitors of the above-described examples and comparative examples was measured by applying the rated voltage.

[0156] Specifically, the capacitance was measured using an Agilent 4268A from HP / Agilent under conditions of 1 kHz and 1 V.

[0157] The measurement results were evaluated as follows. ◎: 90% to 100% of the maximum measured capacity ○: More than 60% and less than 90% of the measured maximum volume △: More than 30% and less than 60% of the measured maximum capacity ×: Less than 30% of the maximum measured capacity

[0158] Figure 7 is a graph showing the capacitances of the multilayer ceramic capacitors according to Example 7 and Comparative Example 7.

[0159] Referring to Figure 7, the capacitance characteristics in Example 7 were relatively improved compared to Comparative Example 7, which had the same sintering temperature.

[0160] Evaluation 3: Evaluation of Equivalent Series Resistance (ESR) Forty multilayer ceramic capacitors, each manufactured according to the examples and comparative examples described above, were welded to an aluminum belt to prepare samples. The ESR of these samples was measured using a KEYSIGHT E4980A model under conditions of 100 kHz and 1.5 ± 0.5 V. ◎: 100% to 110% of the minimum measured ESR ○: Greater than 110% and less than or equal to 130% of the minimum measured ESR. △: Greater than 130% and less than or equal to 160% of the minimum measured ESR. ×: Over 160% of the minimum measured ESR

[0161] Evaluation 4: Evaluation of moisture resistance reliability For the multilayer ceramic capacitors manufactured according to the examples and comparative examples described above, the change in insulation resistance (IR) was measured for 20 hours under conditions of 95°C, 95% relative humidity, and 12V using an ESPEC PR-3J apparatus to evaluate their moisture resistance reliability.

[0162] Specifically, the measurement results were evaluated as follows. ◎: IR is 1.0 × 10 7 Exceeding Ω ○: IR is 1.0 × 106 Ω exceeds and 1.0×10 7 Ω or less △: IR is 1.0×10 5 Ω exceeds and 1.0×10 6 Ω or less ×: IR is 1.0×10 5 Ω less than

[0163] The sintering temperature and evaluation results of the conductive paste for electrodes are shown in Table 1 below.

[0164]

Table 1

[0165] Referring to Table 1 above, in the example where an alloy of Ni and auxiliary elements is located in the region where the internal electrode and the external electrode are in contact, the capacitance characteristics and moisture resistance reliability are improved and the ESR is reduced compared to the comparative example sintered at the same temperature.

Explanation of symbols

[0166] 10: First electrode layer 11: Conductive metal 11a: Ni 11b: Auxiliary element 12: Glass 13: Second interface region 20: Second electrode layer 30: First plating layer 40: Second plating layer 100: Multilayer ceramic capacitor 110: Capacitor body 111: Dielectric layer 121: First internal electrode 122: Second internal electrode 123: First interface region 131: First external electrode 132: Second external electrode

Claims

1. Capacitor body including dielectric layer and internal electrodes; and An external electrode located on the outside of the capacitor body, comprising Ni and an auxiliary element comprising at least one of Sn, Al, Zn, In, and Co; The internal electrode includes a first interface region that is in contact with the external electrode. The first interface region comprises a multilayer ceramic capacitor containing an alloy that includes both Ni and the auxiliary elements.

2. The multilayer ceramic capacitor according to claim 1, wherein the first interface region is defined as a region in which the content of the auxiliary element, as measured by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) along a direction toward the interior of the internal electrode from the interface between the internal electrode and the external electrode, is 5 mol% or more of the total amount of Ni and the auxiliary element.

3. The external electrode includes an electrode layer that is electrically connected to the internal electrode. The multilayer ceramic capacitor according to claim 1, wherein the electrode layer comprises Ni and the auxiliary elements.

4. The electrode layer includes a second interface region in contact with the internal electrode, The multilayer ceramic capacitor according to claim 3, wherein the second interface region comprises an alloy of Ni and the auxiliary elements.

5. The multilayer ceramic capacitor according to claim 4, wherein the second interface region is defined as a region in which the content of the auxiliary element, measured by SEM-EDS along a direction toward the interior of the electrode layer from the interface between the electrode layer and the internal electrode, is 5 mol% to 20 mol% of the total amount of Ni and the auxiliary element.

6. The multilayer ceramic capacitor according to claim 4, wherein the first interface region and the second interface region are connected.

7. The multilayer ceramic capacitor according to claim 3, wherein the electrode layer does not contain Cu.

8. The multilayer ceramic capacitor according to claim 1, wherein the Ni content in the total amount of Ni and auxiliary elements contained in the external electrode is 80 mol% to 95 mol%.

9. The multilayer ceramic capacitor according to claim 1, wherein the content of the auxiliary element in the total amount of Ni and the auxiliary element contained in the external electrode is 5 mol% to 20 mol%.

10. The multilayer ceramic capacitor according to claim 1, wherein the Ni contained in the external electrode is in the form of Ni metal.

11. The multilayer ceramic capacitor according to claim 1, wherein the internal electrode contains Ni, and the internal electrode and the external electrode are electrically connected through the alloy.

12. The multilayer ceramic capacitor according to claim 1, further comprising glass for the external electrode.

13. The glass content is 1 to 40 parts by weight per 100 parts by weight of the total amount of Ni and the auxiliary elements contained in the external electrode, as described in claim 12.

14. The multilayer ceramic capacitor according to claim 1, wherein the external electrode comprises a plurality of Ni metals and a plurality of the auxiliary elements, and the average particle size of the Ni metals and the average particle size of the auxiliary elements contained in the external electrode are 0.05 μm to 10 μm, respectively.

15. A step of applying an electrode layer forming paste to one surface of a capacitor body including a dielectric layer and internal electrodes; and The step includes sintering the electrode layer forming paste to form the electrode layer of the external electrode; The electrode layer forming paste comprises Ni and an auxiliary element containing at least one of Sn, Al, Zn, In, and Co. The internal electrode includes a first interface region that is in contact with the external electrode. A method for manufacturing a multilayer ceramic capacitor, wherein the first interface region includes an alloy of Ni and the auxiliary elements.

16. The method for manufacturing a multilayer ceramic capacitor according to claim 15, wherein the sintering is performed at 500°C to 850°C.

17. The electrode layer includes a second interface region in contact with the internal electrode, The method for manufacturing a multilayer ceramic capacitor according to claim 15, wherein the second interface region includes an alloy of Ni and the auxiliary elements.

18. The method for manufacturing a multilayer ceramic capacitor according to claim 15, wherein the Ni content in the total amount of Ni and auxiliary elements contained in the electrode layer forming paste is 80 mol% to 95 mol%.

19. The method for manufacturing a multilayer ceramic capacitor according to claim 15, wherein the content of the auxiliary element in the total amount of Ni and the auxiliary element contained in the electrode layer forming paste is 5 mol% to 20 mol%.

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