Method for manufacturing a multilayer ceramic capacitor and multilayer ceramic capacitor

Abstract

To provide a manufacturing method of a multilayer ceramic capacitor and a multilayer ceramic capacitor, which ensure moisture resistance reliability by improving the sintering density of a margin portion and prevent cracks caused by a step difference and pores.SOLUTION: A manufacturing method includes the steps of: preparing a ceramic green sheet 211 in which a plurality of internal electrode patterns 221 are formed with a predetermined distance therebetween; forming a ceramic laminate 220 by laminating a plurality of the ceramic green sheets in a first direction; cutting the ceramic laminate to have a side surface from which an end of the internal electrode pattern is exposed in a second direction perpendicular to the first direction; forming a margin portion on the side surface from which the end of the internal electrode pattern is exposed; and forming a ceramic body including a dielectric layer and an internal electrode by firing the cut-out ceramic laminate. The step of forming a margin portion includes a step of flowing ceramic pastes 22, 23 from an upper portion to a lower portion of the cut-out ceramic laminate.SELECTED DRAWING: Figure 5e

Description

[Technical Field]

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

[0002] Generally, electronic components using ceramic materials, such as capacitors, inductors, piezoelectric elements, varistors, or thermistors, comprise a ceramic body made of ceramic material, internal electrodes formed inside the body, and external electrodes provided on the surface of the ceramic body so as to be connected to the internal electrodes.

[0003] Recently, as electronic products have become smaller and more multifunctional, chip components have also tended to become smaller and more sophisticated. As a result, there is a demand for multilayer ceramic capacitors that are small in size and have high capacitance.

[0004] Conventionally, margins were formed by firing the remaining area of ​​the ceramic green sheet, excluding the region where the internal electrode pattern was formed. However, this process of laminating, pressing, and cutting tens to hundreds of layers of ceramic green sheet resulted in steps and warping of the internal electrode pattern. This led to a decrease in the reliability of multilayer ceramic capacitors.

[0005] To solve these problems, conventional methods have been employed in which the internal electrodes are exposed in the width direction of the chip, thereby maximizing the area of ​​the internal electrodes in the width direction through a design without margins. After fabricating such a chip, a margin portion is separately attached to the exposed electrode surface in the width direction of the chip before firing to complete the process.

[0006] However, conventionally, when manufacturing multilayer ceramic capacitors as described above, the dielectric composition for forming the margin portion was not differentiated from the dielectric composition of the ceramic body, and the dielectric composition of the ceramic body was used as is.

[0007] This resulted in a decrease in the physical packing density of the dielectric material within the margin, leading to a problem of reduced density in the margin. Furthermore, a problem arose where the interfacial gap between the end of the internal electrode and the junction surface of the margin was not filled due to a sintering mismatching phenomenon between the dielectric material in the margin and the internal electrode during the sintering process. This resulted in a decrease in the moisture resistance reliability of the multilayer ceramic capacitor.

[0008] Furthermore, in the conventional technology described above, a ceramic green sheet that acts as a margin is physically pressed onto a green chip that has been cut without a margin, and then a sintered body with a rigid body is constructed by high-temperature heat treatment. Therefore, if the adhesive strength between the margin-forming sheet and the electrode exposed surface is insufficient in the pre-sintering stage, it may lead to serious defects such as detachment of the margin and interface cracks.

[0009] Furthermore, during the high-temperature heat treatment process, the shrinkage of the internal electrodes causes a volume change inside the chip, which can create voids between the electrode ends and the margin. These voids may act as starting points for crack formation or become pathways for moisture penetration, potentially leading to a decrease in moisture resistance reliability. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2019-016688 [Overview of the project] [Problems that the invention aims to solve]

[0011] One of the objectives of the present invention is to solve the problem of reduced moisture resistance reliability due to a decrease in sintering density in the margin portion of multilayer ceramic capacitors.

[0012] One of the objectives of the present invention is to solve the problem of cracks and other defects caused by steps and pores.

[0013] However, the objectives of the present invention are not limited to those described above and can be more easily understood in the process of describing specific embodiments of the present invention. [Means for solving the problem]

[0014] According to one embodiment of the present invention, a method for manufacturing a multilayer ceramic capacitor is provided, comprising the steps of: providing a ceramic green sheet on which a plurality of internal electrode patterns are formed at predetermined intervals; stacking a plurality of the ceramic green sheets in a first direction to form a ceramic laminate; cutting the ceramic laminate such that the ends of the internal electrode patterns are exposed on a side surface in a second direction perpendicular to the first direction; forming a margin portion on the side surface where the ends of the internal electrode patterns are exposed; and firing the cut ceramic laminate to form a ceramic body including a dielectric layer and internal electrodes, wherein the step of forming the margin portion includes pouring ceramic paste from the top to the bottom of the cut ceramic laminate.

[0015] According to another embodiment of the present invention, a multilayer ceramic capacitor is provided, comprising a ceramic body including a dielectric layer and a plurality of internal electrodes stacked in a first direction with the dielectric layer in between; margin portions arranged on both sides of the ceramic body facing each other in a second direction perpendicular to the first direction; and external electrodes arranged on both sides facing each other in a third direction perpendicular to the first and second directions and connected to the internal electrodes, wherein the margin portions have a higher density than the dielectric layer. [Effects of the Invention]

[0016] One of the effects of the present invention is to improve the sintering density of the margin portion of a multilayer ceramic capacitor and ensure moisture resistance reliability.

[0017] One of the effects of the present invention is to ensure high reliability of multilayer ceramic capacitors by preventing cracks caused by steps and pores. [Brief explanation of the drawing]

[0018] [Figure 1] It is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 2] It is a schematic perspective view of the ceramic body of a multilayer ceramic capacitor. [Figure 3] It is a cross-sectional view schematically showing a cut cross-section along the line I-I' in FIG. 1. [Figure 4] It is a cross-sectional view schematically showing a cut cross-section along the line II-II' in FIG. 1. [Figure 5a] It is a cross-sectional view and a perspective view schematically showing a manufacturing method of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 5b] It is a cross-sectional view and a perspective view schematically showing a manufacturing method of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 5c] It is a cross-sectional view and a perspective view schematically showing a manufacturing method of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 5d] It is a cross-sectional view and a perspective view schematically showing a manufacturing method of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 5e] It is a cross-sectional view and a perspective view schematically showing a manufacturing method of a multilayer ceramic capacitor according to an embodiment of the present invention. [Figure 6a] It is a schematic perspective view of a multilayer body according to an embodiment of the present invention. [Figure 6b] It is a schematic perspective view of a multilayer body according to an embodiment of the present invention. <从这里开始,前面的内容是根据要求进行的准确翻译,但从这一行开始,原始文本中存在重复的内容,按照任务要求,应保持原始文本的重复格式,因此这里继续重复前面的翻译内容,以确保格式的一致性。]] [Figure 7a] It is a graph showing the results of a moisture resistance reliability test according to a comparative example. [Figure 7b] It is a graph showing the results of a moisture resistance reliability test according to an embodiment of the present invention. [Figure 8a] It is an image obtained by photographing the interface between the margin part of a comparative example and the ceramic body with a scanning electron microscope (SEM). [Figure 8b]This is an image of the interface between the margin portion and the ceramic body of the example, captured by a scanning electron microscope (SEM). [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described below with reference to specific embodiments and accompanying drawings. However, embodiments of the present invention can be modified into several other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to give a more complete explanation of the present invention to a person of the ordinary skill. Accordingly, the shapes and sizes of elements in the drawings may be enlarged or reduced (or highlighted or simplified) for a clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

[0020] Furthermore, in order to clearly illustrate the present invention in the drawings, parts unrelated to the explanation have been omitted, and the size and thickness of each component shown in the drawings are shown arbitrarily for the convenience of explanation; therefore, the present invention is not necessarily limited by the illustrations. Also, components that have the same function within the scope of the same idea are described using the same reference numerals. Moreover, throughout the specification, when a part "includes" a certain component, unless otherwise stated to the contrary, it does not mean that other components are excluded, but rather that other components may be further included.

[0021] In drawings, the first direction can be defined as the lamination direction or thickness (T) direction, the second direction as the width (W) direction, and the third direction as the length (L) direction.

[0022] Referring to Figures 1 to 4, the multilayer ceramic capacitor 100 includes a ceramic body 110 containing a dielectric layer 111 and a plurality of internal electrodes 121, 122 stacked in a first direction with the dielectric layer 111 in between; margin portions 112, 113 arranged on both sides of the ceramic body 110 facing each other in a second direction perpendicular to the first direction; and external electrodes 131, 132 arranged on both sides facing each other in a third direction perpendicular to the first and second directions and connected to the internal electrodes 121, 122. Furthermore, the ceramic body 110 may include a capacitance forming portion Ac, which contributes to the capacitance formation of the multilayer ceramic capacitor 100, formed by repeatedly stacking a plurality of internal electrodes 121, 122 with the dielectric layer 111 in between; and upper and lower cover portions 114, 115, which are stacked on the upper and lower surfaces of the capacitance forming portion Ac in a first direction or thickness direction, respectively.

[0023] Conventionally, margin portions 112 and 113 were formed by physically pressing a ceramic green sheet for forming margin portions 112 and 113 onto the ceramic body 110 and then heat-treating it. Alternatively, margin portions 112 and 113 were formed using a ceramic green sheet having the same dielectric composition as the ceramic green sheet forming the dielectric layer 111. This resulted in a problem where the physical charge density of the dielectric was low within the margin portions 112 and 113, reducing the density of the margin portions 112 and 113, and consequently lowering the moisture resistance reliability of the multilayer ceramic capacitor 100.

[0024] This embodiment aims to solve the problem and provides a method for manufacturing a multilayer ceramic capacitor and a multilayer ceramic capacitor with excellent moisture resistance reliability by preventing the occurrence of steps due to the internal electrodes 121 and 122 and improving the density of the margin portions 112 and 113.

[0025] First, with reference to Figures 5a to 5e, a method for manufacturing a multilayer ceramic capacitor according to one embodiment of the present invention will be described in detail.

[0026] A method for manufacturing a multilayer ceramic capacitor according to one embodiment of the present invention includes the steps of: providing a ceramic green sheet 211 on which a plurality of internal electrode patterns 221, 222 are formed at predetermined intervals; stacking a large number of the ceramic green sheets 211 in a first direction to form a ceramic laminate 220; cutting the ceramic laminate 220 such that the ends of the internal electrode patterns 221, 222 are exposed on a side surface in a second direction perpendicular to the first direction; forming margin portions 212, 213 on the side surfaces where the ends of the internal electrode patterns 221, 222 are exposed; and firing the cut ceramic laminate 220 to form a ceramic body including a dielectric layer and internal electrodes, wherein the step of forming the margin portions 212, 213 includes the step of pouring ceramic paste 22, 23 from the top to the bottom of the cut ceramic laminate 220.

[0027] As shown in Figure 5a, a plurality of first internal electrode patterns 221 are formed on the ceramic green sheet 211 at predetermined intervals. In this case, the first internal electrode patterns can be striped, and the plurality of first internal electrode patterns 221 can be formed parallel to each other.

[0028] The ceramic green sheet 211 is produced by mixing ceramic powder, a binder, and a solvent to create a ceramic slurry, and then fabricating the ceramic slurry into a sheet with a thickness of several micrometers using a doctor blade method or similar. When the ceramic green sheet 211 is fired, it becomes the dielectric layer 111 that constitutes the ceramic body 110.

[0029] The above ceramic powder is not particularly limited as long as sufficient capacitance can be obtained. For example, barium titanate powder, lead-composite perovskite powder, or strontium titanate powder can be used. The above barium titanate powder may include BaTiO3-based ceramic powder, and examples of the above ceramic powder include BaTiO3, BaTiO3 in which Ca (calcium), Zr (zirconium), etc. are partially solid-dissolved (BaTiO3).1-x Ca x )TiO3, Ba(Ti 1-y Ca y )O3, (Ba 1-x Ca x )(Ti 1-y Zr y )O3 or Ba(Ti 1-y Zr y )O3 and the like can be mentioned.

[0030] At this time, the average thickness td of the ceramic green sheet 211 can be arbitrarily changed in consideration of the size and capacitance of the multilayer ceramic capacitor, and can be 0.6 μm or less for miniaturization and high capacitance of the multilayer ceramic capacitor, but the present invention is not limited thereto. The average thickness td of the ceramic green sheet 211 can be measured from an image obtained by scanning the ceramic green sheet 211 with a scanning electron microscope (SEM), and the thickness can be measured at a number of points on one ceramic green sheet 211 to measure an average value. Further, measurement of such an average value can be extended to a number of ceramic green sheets 211 to measure a more generalized average value. By satisfying that the thickness td of the ceramic green sheet is 0.6 μm or less, the average thickness of the dielectric layer 111 after firing can be 0.4 μm or less.

[0031] The first internal electrode pattern 221 can be formed by an internal electrode conductive paste containing a conductive metal. The method of forming the first internal electrode pattern 221 on the ceramic green sheet 211 is not particularly limited, and for example, it can be formed by a screen printing method or a gravure printing method. Further, the internal electrode conductive paste can contain a co-material powder, a dispersant, and a solvent, and the present invention is not limited thereto.

[0032] The conductive metals mentioned above may include, but are not limited to, one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

[0033] Furthermore, although not shown in the figures, a second internal electrode pattern 222 can be formed on another ceramic green sheet 211 at predetermined intervals. The ceramic green sheet 211 on which the first internal electrode pattern 221 is formed can be referred to as the first ceramic green sheet, and the ceramic green sheet 211 on which the second internal electrode pattern 222 is formed can be referred to as the second ceramic green sheet.

[0034] Next, as shown in Figure 5b, the first and second ceramic green sheets 211 can be alternately stacked in the first direction so that the first internal electrode pattern 221 and the second internal electrode pattern 222 are intersecting. After firing, the first and second internal electrode patterns 221 and 222 can become the first and second internal electrodes 121 and 122 of the ceramic body 110.

[0035] At this time, the average thickness te of the internal electrode patterns 221 and 222 can be arbitrarily changed considering the size and capacitance of the multilayer ceramic capacitor, and can be 0.5 μm or less in order to miniaturize and increase the capacitance of the multilayer ceramic capacitor, but the present invention is not limited thereto. The average thickness te of the internal electrode patterns 221 and 222 can be measured from an image obtained by scanning the internal electrode patterns 221 and 222 with a scanning electron microscope (SEM), and the average value can be measured by measuring the thickness at many points on one internal electrode pattern 221 or 222. Furthermore, such measurement of the average value can be extended to many internal electrode patterns 221 and 222 to measure a more generalized average value. By satisfying that the thickness te of the internal electrode patterns 221 and 222 is 0.6 μm or less, the average thickness of the internal electrodes 121 and 122 after firing can be 0.4 μm or less.

[0036] Next, referring to Figure 5c, a ceramic laminate 220 can be formed by stacking a large number of ceramic green sheets 211, on which the first and second internal electrode patterns 221 and 222 are formed, in the first direction. Next, as shown in Figure 5d, the ceramic laminate 220 can be cut along mutually orthogonal C1-C1 and C2-C2 cutting lines such that the ends of the internal electrode patterns 221 and 222 are exposed on the sides in the second direction. More specifically, by cutting along the C1-C1 cutting line, the ceramic laminate 220 can be divided into a laminate body 210 having the form of multiple laminate bars. At this time, the ends of the first and second internal electrode patterns 221 and 222 can be exposed on the cut surface of the laminate body 210. After this, by cutting along the C2-C2 cutting line, the laminate body 210 can be divided into a laminate body 210 having the form of multiple laminate chips.

[0037] Next, as shown in Figure 5e, first and second margin portions 212 and 213 can be formed on the sides of multiple laminated bodies 210 where the ends of the internal electrode patterns 221 and 222 are exposed. At this time, the step of forming the first and second margin portions 212 and 213 may include the step of pouring ceramic paste 22 and 23 from the top to the bottom of the cut ceramic laminate 220.

[0038] Conventionally, margin portions 212 and 213 were formed by firing the remaining region of the ceramic green sheet 211, excluding the region where the internal electrode patterns 221 and 222 were formed. However, during the process of laminating, pressing, and cutting tens to hundreds of layers of ceramic green sheet 211, a step difference occurred, causing the internal electrode patterns 221 and 222 to warp.

[0039] Furthermore, conventionally, in order to solve the problem of the above-mentioned step difference occurring, a ceramic green sheet for forming the margin portion was attached by physical pressure, and then the margin portions 212 and 213 were formed by high-temperature heat treatment. As a result, if the adhesive strength between the ceramic green sheet for forming the margin portion and the laminated body 210 was insufficient, problems arose such as poor appearance due to detachment of the margin portion, crack formation, and reduced moisture resistance reliability.

[0040] On the other hand, according to one embodiment of the present invention, after cutting the ceramic laminate 220 so that the ends of the internal electrode patterns 221 and 222 are exposed on the sides, separate ceramic pastes 22 and 23 are poured from the top to the bottom of the cut ceramic laminate 220 to form the first and second margin portions 212 and 213. This prevents the occurrence of steps caused by the internal electrode patterns 221 and 222, and provides a highly reliable multilayer ceramic capacitor.

[0041] Furthermore, since the ceramic pastes 22 and 23 are poured from the top to the bottom of the cut ceramic laminate 220 to form the first and second margin portions 212 and 213, it is possible to prevent cosmetic defects and crack formation due to the attachment and detachment of the margin portions 212 and 213, thereby improving the moisture resistance reliability of the multilayer ceramic capacitor.

[0042] Furthermore, according to one embodiment of the present invention, margin portions 212 and 213 can be formed with ceramic pastes 22 and 23 that have a high packing density of ceramic powder. Since the liquid ceramic pastes 22 and 23 have a higher packing density and dispersibility of ceramic powder than the ceramic slurry that forms the ceramic green sheet 211, fewer pores are produced when forming the margin portions 212 and 213, and margin portions 212 and 213 with high sintering density can be realized. As a result, the margin portions 112 and 113 of the multilayer ceramic capacitor 100 after firing can have a higher density than the dielectric layer 111.

[0043] The average thickness of the margin portions 112 and 113 after firing can be arbitrarily changed considering the size and capacitance of the multilayer ceramic capacitor 100, and can be between 2 μm and 15 μm. The average thickness of the margin portions 112 and 113 can be measured from images obtained by scanning the cross-sections of the multilayer ceramic capacitor 100 in the first and second directions using a scanning electron microscope (SEM), and the average value can be determined by measuring the thickness of the margin portions 112 and 113 at a number of points.

[0044] According to one embodiment of the present invention, the ceramic pastes 22 and 23 can have a higher viscosity than the ceramic slurry used to form the ceramic green sheet 211. The higher viscosity of the ceramic pastes 22 and 23 means that the ceramic pastes 22 and 23 have a higher packing density of ceramic powder than the ceramic slurry. Because the ceramic pastes 22 and 23 have a higher viscosity than the ceramic slurry used to form the ceramic green sheet 211, gravity can prevent the ceramic pastes 22 and 23 from becoming unevenly distributed in the lower region of the side surface of the laminated body 210. This allows the ceramic pastes 22 and 23 to be uniformly applied to the upper and lower regions of the side surface of the laminated body 210, and the ceramic pastes 22 and 23, which have excellent packing density and dispersibility of ceramic powder, can be used to form margin portions 212 and 213 with excellent sintering density.

[0045] Conventional ceramic slurries have a viscosity in the range of 1,000 to 3,000 CPS (10 rpm), but the viscosity of ceramic pastes 22 and 23 according to one embodiment of the present invention can be 20,000 to 40,000 CPS (10 rpm). When the viscosity of ceramic pastes 22 and 23 falls within the above range, the high viscosity makes it difficult to apply the ceramic pastes 22 and 23 to the sides of the laminated body 210 using conventional manufacturing methods. Therefore, by including a step of flowing the ceramic laminate from the top to the bottom of the ceramic laminate 220, it is possible to apply the pastes to the sides of the laminated body 210. This makes it possible to realize a multilayer ceramic capacitor 100 with high density in the margin portions 112 and 113 after firing.

[0046] According to one embodiment of the present invention, the step of forming margin portions 212 and 213 may further include a step of suctioning the ceramic paste 22 and 23 from the bottom of the cut ceramic laminate 220. More specifically, the ceramic paste 22 and 23 can be suctioned by placing a suction device 300 between a plurality of laminate bodies 210 formed by cutting the ceramic laminate 220. In the case of ceramic paste 22 and 23 with a high filling density of ceramic powder and high viscosity, gravity alone may not allow it to flow from the top to the bottom of the side surface of the laminate body 210. In this case, the step of suctioning the ceramic paste 22 and 23 with the suction device 300 may further include a step of applying the ceramic paste 22 and 23 to the side surface of the laminate body 210 with a uniform thickness.

[0047] Referring to Figure 6a, the step of forming the margin portions 212 and 213 can be carried out by providing multiple laminated bodies 210 in a laminated bar state formed by cutting the ceramic laminate 220, and applying the ceramic paste 22 and 23 to the laminated bodies 210 in a laminated bar state by flowing it from the top to the bottom of the side surface of the laminated bodies 210. Multiple laminated bodies 210 in a laminated bar state can be formed by cutting the ceramic laminate 220 along the C1-C1 cutting line.

[0048] Furthermore, referring to Figure 6b, the step of forming the margin portions 212 and 213 can be carried out by providing multiple laminated bodies 210 in a laminated chip state formed by cutting the ceramic laminate 220, and applying the ceramic paste 22 and 23 to the laminated bodies 210 in a laminated chip state by flowing it from the top to the bottom of the side surface of the laminated bodies 210. Multiple laminated bodies 210 in a laminated chip state can be formed by cutting the ceramic laminate 220 along the cutting lines C1-C1 and C2-C2.

[0049] Subsequently, by firing the multiple cut laminated bodies 210, a ceramic body 110 including a dielectric layer 111 and internal electrodes 121 and 122 can be formed. Furthermore, in the ceramic body 110, first and second external electrodes 131 and 132 can be formed on the fifth and sixth surfaces 5 and 6 of the ceramic body 110, where the first and second internal electrodes 121 and 122 are alternately exposed. The first and second external electrodes 131 and 132 can be formed by dipping the ceramic body 110 into a conductive paste for external electrodes and firing it, but the present invention is not limited thereto, and the external electrodes 131 and 132 can also be formed by attaching or transferring a sheet, or by electroless plating or sputtering.

[0050] The following describes in detail another embodiment of the present invention: a multilayer ceramic capacitor.

[0051] According to another embodiment of the present invention, a multilayer ceramic capacitor 100 is provided, comprising a ceramic body 110 including a dielectric layer 111 and a plurality of internal electrodes 121, 122 stacked in a first direction with the dielectric layer in between; margin portions 112, 113 arranged on both sides of the ceramic body 110 facing each other in a second direction perpendicular to the first direction; and external electrodes 131, 132 arranged on both sides facing each other in a third direction perpendicular to the first and second directions and connected to the internal electrodes 121, 122, wherein the margin portions 112, 113 have a higher density than the dielectric layer 111.

[0052] There are no particular restrictions on the specific shape of the ceramic body 110, but as shown in the figure, the ceramic body 110 can be hexahedral or a similar shape. Due to the shrinkage of the ceramic powder contained in the ceramic body 110 during the firing process and the polishing of the edges, the ceramic body 110 may not be a perfectly straight hexahedron, but it can be substantially hexahedral.

[0053] The ceramic body 110 may have first and second surfaces 1 and 2 facing each other in a first direction, third and fourth surfaces 3 and 4 connected to the first and second surfaces 1 and 2 and facing each other in a second direction, and fifth and sixth surfaces 5 and 6 connected to the first and second surfaces 1 and 2 and connected to the third and fourth surfaces 3 and 4 and facing each other in a third direction.

[0054] The multiple dielectric layers 111 forming the ceramic body 110 are in a fired state, and the boundaries between adjacent dielectric layers 111 can be integrated to such an extent that they are difficult to confirm without using a scanning electron microscope (SEM).

[0055] The internal electrodes 121 and 122 can be arranged alternately with the dielectric layer 111, and the first internal electrode 121 and the second internal electrode 122 can be arranged facing each other with the dielectric layer 111 in between.

[0056] In other words, the first and second internal electrodes 121 and 122 are a pair of electrodes having different polarities from each other. They can be formed by printing a conductive paste for internal electrodes containing a conductive metal to a predetermined thickness onto the dielectric layer 111, with the dielectric layer 111 in between, so that they are alternately exposed through the fifth and sixth surfaces 5 and 6 of the ceramic body 110 along the stacking direction of the dielectric layer 111, and they can be electrically insulated from each other by the dielectric layer 111 placed in between.

[0057] The external electrodes 131 and 132 are formed on the outside of the ceramic body 110 and connected to the internal electrodes 121 and 122. Specifically, they may include first and second external electrodes 131 and 132 arranged on fifth and sixth surfaces 5 and 6 of the ceramic body 110, respectively, which face each other in the third direction. As a result, the first external electrode 131 can be connected to a plurality of first internal electrodes 121 exposed through the fifth surface 5 of the ceramic body 110, and the second external electrode 132 can be connected to a plurality of second internal electrodes 122 exposed through the sixth surface 6 of the ceramic body 110.

[0058] In this case, the external electrodes 131 and 132 can be fired electrodes containing a conductive metal and glass, and the conductive metal can be, for example, one of silver (Ag), lead (Pb), platinum (Pt), nickel (Ni), and copper (Cu), or an alloy thereof, but the present invention is not limited thereto.

[0059] The external electrodes 131 and 132 described above can consist of multiple layers, and a plating layer can be placed on the external electrodes 131 and 132. The plating layer can serve to improve the mounting characteristics of the multilayer ceramic capacitor 100.

[0060] The above-mentioned plating layer may contain one or more of Ni, Sn, Cu, Pd, and their alloys, and may consist of multiple layers. In particular, it may include a nickel (Ni) plating layer and a tin (Sn) plating layer that are sequentially laminated on the external electrodes 131 and 132.

[0061] The margin portions 112 and 113 include a first margin portion 112 and a second margin portion 113, respectively, which are positioned on the third and fourth surfaces 3 and 4 of the ceramic body 110 facing the second direction, and together with the upper and lower cover portions 114 and 115, they can serve to prevent damage to the internal electrodes 121 and 122 due to physical or chemical stress.

[0062] In this case, the margin portions 112 and 113 can have a higher density than the dielectric layer 111. Furthermore, the margin portions 112 and 113 can have a higher density than the upper and lower cover portions 114 and 115. As an example of a method for measuring density, the cross-sections of the ceramic body 110 in the first and second directions can be photographed with a scanning electron microscope (SEM), and the density can be measured by using a computer program such as SigmaScan Pro to measure the dielectric area ratio of the margin portions 112 and 113 excluding the pore area relative to the total area of ​​the SEM images. However, the present invention is not limited to this.

[0063] The margin portions 112 and 113 are formed by firing a ceramic paste with a high packing density of ceramic powder, and the dielectric layer 111 is formed by firing a ceramic green sheet with a lower packing density of ceramic powder than the ceramic paste. Therefore, the margin portions 112 and 113 can have a higher sintering density than the dielectric layer 111.

[0064] In this case, the density at the interface between the margin portions 112 and 113 and the ceramic body 110 can be 98% or more. This prevents external moisture from penetrating from the interface between the margin portions 112 and 113 and the ceramic body 110, thereby providing a multilayer ceramic capacitor 100 with excellent moisture resistance reliability. As an example of a method for measuring the density at the interface, the density can be measured in a region of length in the first direction × length in the second direction = 10 μm × 10 μm, based on the surfaces where the margin portions 112 and 113 and the ceramic body 110 are in contact in the cross-sections of the ceramic body 110 in the first and second directions, but the present invention is not limited to this. Furthermore, as described above, the density at the interface between the margin portions 112 and 113 and the ceramic body 110 can be measured by taking images of the cross-sections of the ceramic body 110 in the first and second directions using a scanning electron microscope (SEM), and then measuring the SEM images using a computer program such as SigmaScan Pro. At this time, by measuring the density at multiple cross-sections in the first and second directions and calculating the average value, the density at the interface between the margin portions 112 and 113 and the ceramic body 110 can be further generalized.

[0065] The multilayer ceramic capacitor 100 according to the other embodiment of the present invention described above may have the same configuration as the embodiment of the multilayer ceramic capacitor 100 according to the embodiment described above. Therefore, any description that overlaps with the embodiment described above will be omitted.

[0066] [Examples] After forming a ceramic laminate 220 by stacking ceramic green sheets 211 on which internal electrode patterns 221 and 222 were formed, the ceramic laminate was cut to form multiple laminated bodies 210, and margin portions 212 and 213 were formed on the sides of the laminated bodies 210. Thereafter, the laminated bodies 210 were subjected to a plasticization process at a temperature of 400°C or less in a nitrogen atmosphere and fired at a firing temperature of 1250°C or less and a hydrogen concentration of 1%H2 or less to provide a ceramic body 110 including a dielectric layer 111 and internal electrodes 121 and 122.

[0067] At this time, the moisture resistance reliability and density were measured for an example manufactured according to an embodiment of the present invention in which ceramic paste 22 and 23 is poured from the top to the bottom of the cut ceramic laminate 220, and for a comparative example in which a ceramic green sheet was attached to form a margin portion as in the conventional method. At this time, the moisture resistance reliability evaluation was performed under 1-2Vr, 8585 conditions (85°C, relative humidity 85%).

[0068] Figure 7a is a graph evaluating the humidity resistance reliability of the comparative example, and Figure 7b is a graph evaluating the humidity resistance reliability of the example. According to Figures 7a and 7b, it can be seen that problems occurred with the humidity resistance reliability in the comparative example, while it can be confirmed that the humidity resistance reliability was excellent in the example.

[0069] Figure 8a shows cross-sections of the comparative example ceramic body 110 cut in the first and second directions, with images of a portion of the interface between the margin portions 112 and 113 and the ceramic body 110 captured by a scanning electron microscope (SEM). Figure 8b shows cross-sections of the example ceramic body 110 cut in the first and second directions, with images of a portion of the interface between the margin portions 112 and 113 and the ceramic body 110 captured by a scanning electron microscope (SEM).

[0070] Subsequently, the density at the interface between the margin portions 112 and 113 and the ceramic body 110 was measured by using the SigmaScan Pro program to measure the ratio of dielectric area excluding pores at the interface between the margin portions 112 and 113 and the ceramic body 110. The density was measured for three samples each of the examples and comparative examples, and was measured in a region of length in the first direction × length in the second direction = 10 μm × 10 μm, based on the surface where the margin portions 112 and 113 and the ceramic body 110 are in contact.

[0071] In the comparative example, the average density at the interface between the margin portions 112 and 113 and the ceramic body 110 was 97.4%, while in the example, the average density at the interface between the margin portions 112 and 113 and the ceramic body 110 was 98.92%. This confirms that the density at the interface between the margin portions 112 and 113 and the ceramic body 110 is improved in the example.

[0072] The present invention is not limited by the embodiments described above and the accompanying drawings, but rather is limited by the claims provided. Therefore, various forms of substitution, modification, and alteration are possible by persons with ordinary skill in the art, without departing from the technical idea of ​​the present invention as described in the claims, and these also fall within the scope of the present invention. [Explanation of symbols]

[0073] 100 Multilayer Ceramic Capacitors 110 Ceramic body 112 First Margin Section 113 Second Margin Section 114 Upper cover section 115 Lower cover section 121 1st internal electrode 122 2nd internal electrode 131 1st external electrode 132 2nd external electrode 211 Ceramic Green Sheet 221 First internal electrode pattern 222 Second internal electrode pattern 210 Laminated Body 220 Ceramic Laminate 22, 23 Ceramic paste 300 Suction device

Claims

1. The steps include providing a ceramic green sheet on which multiple internal electrode patterns are formed at predetermined intervals, The steps include: stacking a large number of the aforementioned ceramic green sheets in a first direction to form a ceramic laminate; The steps include cutting the ceramic laminate such that the end of the internal electrode pattern has a side surface exposed in a second direction perpendicular to the first direction, The steps include forming a margin portion on the side surface where the end of the internal electrode pattern is exposed, The process includes the step of firing the cut ceramic laminate to form a ceramic body including a dielectric layer and internal electrodes, A method for manufacturing a multilayer ceramic capacitor, wherein the step of forming the margin portion includes the step of pouring ceramic paste from the top to the bottom of the cut ceramic laminate.

2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the ceramic paste has a higher viscosity than the ceramic slurry used to form the ceramic green sheet.

3. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the step of forming the margin portion further includes the step of sucking the ceramic paste from the lower part of the cut ceramic laminate.

4. The method for manufacturing a multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the margin portion has a higher density than the dielectric layer.

5. The method for manufacturing a multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the step of forming the margin portion is performed in a state in which the ceramic laminate is cut and a plurality of laminated bars are formed.

6. The method for manufacturing a multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the step of forming the margin portion is performed in a plurality of stacked chip states formed by cutting the ceramic stack.

7. A method for manufacturing a multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the average thickness of the margin portion is 2 μm to 15 μm.

8. A method for manufacturing a multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the average thickness of the dielectric layer is 0.4 μm or less.

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