Ceramic electronic components

Abstract

We provide highly reliable ceramic electronic components and enable thinning of the dielectric layer without reducing the dielectric constant. [Solution] A ceramic electronic component 100 according to one embodiment of the present invention comprises a body 110 including a dielectric layer 111 and internal electrodes 121, 122, and external electrodes 131, 132 disposed on the body 110 and connected to the internal electrodes 121, 122. The dielectric layer 111 includes a plurality of crystal grains and crystal grain boundaries 14 disposed between adjacent crystal grains. The crystal grain boundaries 14 include Sn, a rare earth element, and a first minor component. The rare earth element includes Dy, the first minor component includes Si, and the plurality of crystal grains may mainly consist of BaTiO3.

Description

Technical Field

[0001] The present invention relates to a ceramic electronic component. Background Art

[0002] A multi-layered ceramic capacitor (MLCC), which is one type of ceramic electronic component, is a chip-shaped capacitor mounted on a printed circuit board of various electronic products such as video equipment including liquid crystal displays (LCD) and plasma display panel (PDP), computers, smartphones and mobile phones, and functions to charge or discharge electricity.

[0003] Such a multi-layered ceramic capacitor can be used as a component for various electronic devices due to its advantages of being compact, ensuring high capacitance, and being easy to mount. In recent years, as various electronic devices such as computers and mobile devices have become smaller and have higher output, demands for size reduction and higher capacitance of multi-layered ceramic capacitors have also been increasing.

[0004] To achieve size reduction and higher capacitance of multi-layered ceramic capacitors, it is necessary to reduce the thickness of dielectric layers and internal electrodes and increase the number of laminated layers. At present, the thickness of dielectric layers has reached a level of approximately 0.6 µm, and the trend toward thinner layers is progressing. However, as the thickness of the dielectric layer decreases, the electric field applied to the dielectric at the same operating voltage increases, so ensuring the reliability of the dielectric is essential. Summary of the Invention Problems to be Solved by the Invention

[0005] One of several objects of the present invention is to provide a ceramic electronic component with excellent reliability.

[0006] One of the several objectives of this invention is to thin the dielectric layer without reducing the dielectric constant.

[0007] However, the object of the present invention is not limited to the above-described content and can be more easily understood in the process of describing specific embodiments of the present invention. [Means for solving the problem]

[0008] A ceramic electronic component according to one embodiment of the present invention comprises a body including a dielectric layer and internal electrodes, and external electrodes disposed on the body and connected to the internal electrodes, wherein the dielectric layer includes a plurality of crystal grains and crystal grain boundaries disposed between adjacent crystal grains, the crystal grain boundaries include Sn, a rare earth element and a first minor component, the rare earth element includes Dy, the first minor component includes Si, and the plurality of crystal grains may mainly consist of BaTiO3.

[0009] In one embodiment of the present invention, the ceramic electronic component can further be such that when the elemental ratio of Sn, rare earth elements, and the first minor component contained in the grain boundary is Sn:rare earth elements:first minor component = 1:x:y, x is between 0.01 and 10.0, and y is between 0.01 and 10.0. [Effects of the Invention]

[0010] One of the various effects of the present invention is that reliability can be improved by arranging a secondary phase containing Sn, rare earth elements, and liquid phase elements at the dielectric grain boundaries.

[0011] One of the various effects of the present invention is that reliability can be improved by controlling the Sn distribution contained in the grain boundaries and within the grains.

[0012] However, the diverse yet significant advantages and effects 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. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic perspective view of a ceramic electronic component according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view along the line I-I' in Figure 1. [Figure 3] This is a schematic cross-sectional view along the line II-II' in Figure 1. [Figure 4] This is an exploded perspective view showing a disassembled body of a ceramic electronic component according to one embodiment of the present invention. [Figure 5] Figure 2 is an enlarged view of region P, and is a schematic diagram showing the crystal grain structure of a dielectric layer according to one embodiment of the present invention. [Figure 6] This graph shows the Sn concentration distribution in the first crystal grain. [Figure 7] This graph shows the Sn concentration distribution in the second crystal grain. [Figure 8] These are images of a cross-section of the dielectric layer of the invention example scanned using STEM (a), an image of the Sn element mapped using STEM-EDS (b), and an image of the Dy element mapped using STEM-EDS (c). [Figure 9] The images show (a) a cross-section of the dielectric layer of the comparative example scanned using STEM, (b) an image of the Sn element mapped using STEM-EDS, and (c) an image of the Dy element mapped using STEM-EDS. [Modes for carrying out the invention]

[0014] 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 with average skill in the art. 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.

[0015] Furthermore, in order to clearly illustrate the present invention in the drawings, parts unrelated to the explanation have been omitted, and the sizes and thicknesses of each illustrated component are shown arbitrarily for the convenience of explanation; therefore, the present invention is not necessarily limited by the illustrations. Also, components with the same function within the scope of the same idea can be described using the same reference numerals. Moreover, throughout the specification, "including" a component means that other components may be included, rather than excluding them, unless otherwise stated to the contrary.

[0016] In drawings, the first direction can be defined as the lamination direction or the thickness (T) direction, the second direction as the length (L) direction, and the third direction as the width (W) direction.

[0017] [Ceramic electronic components] Figure 1 is a schematic perspective view of a ceramic electronic component according to one embodiment of the present invention; Figure 2 is a schematic cross-sectional view along the line I-I' in Figure 1; Figure 3 is a schematic cross-sectional view along the line II-II' in Figure 1; Figure 4 is an exploded perspective view showing the main body of a ceramic electronic component according to one embodiment of the present invention; and Figure 5 is an enlarged view of region P in Figure 2, which is a schematic diagram showing the crystal grain structure of the dielectric layer according to one embodiment of the present invention.

[0018] Hereinafter, a ceramic electronic component 100 according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. A multi-layered ceramic capacitor (hereinafter referred to as "MLCC") will be described as an example of the ceramic electronic component, but the present invention is not limited thereto, and can be applied to various ceramic electronic components using ceramic materials, such as inductors, piezoelectric elements, varistors, or thermistors.

[0019] A ceramic electronic component 100 according to an embodiment of the present invention includes a main body 110 including dielectric layers 111 and internal electrodes 121 and 122, and external electrodes 131 and 132 disposed on the main body and connected to the internal electrodes, wherein the dielectric layer 111 includes a plurality of crystal grains 11, 12, 13 and grain boundaries 14 disposed between adjacent crystal grains, the grain boundaries 14 include a secondary phase containing Sn, a rare earth element and a liquid phase element, the rare earth element includes one or more of Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, Tb, Tm, La, Gd, and Yb, and the liquid phase element can include one or more of Si, Mg and Al.

[0020] In the main body 110, dielectric layers 111 and internal electrodes 121 and 122 may be alternately stacked.

[0021] There is no particular limitation on the specific shape of the main body 110, and as illustrated, the main body 110 may be in a hexahedral shape or a shape similar thereto. Due to shrinkage of the ceramic powder contained in the main body 110 during the firing process, the main body 110 is not a perfect hexahedron with completely straight edges, but can be substantially hexahedral.

[0022] The main body 110 may have first and second surfaces 1 and 2 opposed to each other in a first direction, third and fourth surfaces 3 and 4 connected to the first and second surfaces 1 and 2 and opposed to each other in a second direction, and fifth and sixth surfaces 5 and 6 connected to the first and second surfaces 1 and 2, connected to the third and fourth surfaces 3 and 4, and opposed to each other in a third direction.

[0023] The multiple dielectric layers 111 forming the main 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).

[0024] The dielectric layer 111 includes a plurality of crystal grains 11, 12, 13 and crystal grain boundaries 14 arranged between adjacent crystal grains, wherein the crystal grain boundaries 14 include a secondary phase containing Sn, a rare earth element, and a liquid phase element, the rare earth element includes one or more of Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, Tb, Tm, La, Gd, and Yb, and the liquid phase element may include one or more of Si, Mg, and Al.

[0025] Multilayer ceramic capacitors (MLCCs), a type of ceramic electronic component, are trending towards higher capacitance and thinner layers. To reduce the thickness of the dielectric layer, the base material must be finely milled. However, simply milling the base material makes it difficult to control grain growth, which can lead to localized thinning of the dielectric layer. This reduction in grain boundary resistance, corresponding to a decrease in the number of grain boundaries, can act as a major cause of breakdown voltage (BDV) and reliability degradation.

[0026] One way to strengthen grain boundary resistance is to increase the amount of liquid phase elements added. However, if the amount of liquid phase elements added is excessive, it can induce side effects such as an increase in firing temperature. Therefore, a method is needed that can strengthen grain boundary resistance while minimizing the increase in liquid phase elements.

[0027] According to one embodiment of the present invention, grain boundary resistance can be strengthened while minimizing the increase in liquid phase elements by including a secondary phase containing Sn, rare earth elements, and liquid phase elements at the grain boundary. Generally, rare earth elements and liquid phase elements can be included in the grain boundary 14, but if Sn is not included in the grain boundary 14, the effect of improving grain boundary resistance may be insufficient, and the content of liquid phase elements may become excessive in order to ensure a sufficient improvement in grain boundary resistance. When Sn is included in the grain boundary, grain boundary resistance can be effectively improved by forming a secondary phase with rare earth elements and liquid phase elements. This makes it possible to achieve high reliability while thinning the dielectric layer.

[0028] There is no particular limit to the content of Sn, rare earth elements, and liquid phase elements contained in the above secondary phase. For example, when the atomic ratio of Sn, rare earth elements, and liquid phase elements contained in the above secondary phase is Sn:rare earth elements:liquid phase elements = 1:x:y, x can be between 0.01 and 10.0, and y can be between 0.01 and 10.0.

[0029] At this time, the atomic weights of Sn, rare earth elements, and liquid phase elements contained in the grain boundary 14 can be measured by creating a line profile using STEM-EDS, where the line has a length of 5 nm perpendicular to the grain boundary and its center coincides with the center of the grain boundary.

[0030] In one embodiment, the rare earth element may be Dy, and the liquid phase element may be Si. This allows the grain boundaries to include a Sn-Dy-Si secondary phase.

[0031] In one embodiment, the plurality of crystal grains include at least one first crystal grain 13, and the first crystal grain has a core-shell structure including a core 13a and a shell 13b surrounding the core, and the shell 13b of the first crystal grain may include a first region 13b1 surrounding the core and a second region 13b2 surrounding the first region.

[0032] Referring to Figure 6, if we define the average Sn content of the grain boundary 14 as Cg, and define the average Sn content of the core 13a, first region 13b1, and second region 13b2 of the first crystal grain as C1, C2, and C3, respectively, then we can satisfy C2>Cg>C3>C1.

[0033] In other words, the Sn content can have the lowest value in the core 13a, the highest value in the first region 13b1 surrounding the core, and a concentration gradient in the second region 13b2 where the Sn content decreases and then increases again as it approaches the grain boundary 14.

[0034] By satisfying this Sn concentration gradient, grain growth can be suppressed, a secondary phase containing Sn, rare earth elements, and liquid phase elements can be easily formed at the grain boundaries, and grain boundary resistance can be effectively improved.

[0035] In one embodiment, Cg, C1, C2, and C3 can satisfy one or more of the following conditions: Cg≧1.1*C3, Cg≧2.0*C1, and C2≧1.3*Cg. That is, they can satisfy one or two of the following conditions: Cg≧1.1*C3, Cg≧2.0*C1, and C2≧1.3*Cg, or they can satisfy all of the following conditions: Cg≧1.1*C3, Cg≧2.0*C1, and C2≧1.3*Cg.

[0036] When the average Sn content (Cg) of the grain boundary is 1.1 times or more than the average Sn content (C3) of the second region, it has the effect of improving the dielectric strength.

[0037] When the average Sn content (Cg) at the grain boundaries is 2.0 times or more than the average Sn content (C1) at the core, it has the effect of suppressing the overgrowth of crystal grains.

[0038] When the average Sn content (C2) of the first region is 1.3 times or more than the average Sn content (Cg) of the grain boundaries, it has the effect of improving high-temperature reliability.

[0039] On the other hand, the concentration gradient of rare earth elements can also have a shape similar to that of the Sn concentration gradient.

[0040] In other words, if we define the average content of rare earth elements at the grain boundary 14 as Cg', and define the average content of rare earth elements at the core 13a, first region 13b1, and second region 13b2 of the first crystal grain as C1, C2', and C3', respectively, then we can satisfy C2'>Cg'>C3'>C1'.

[0041] Furthermore, the above Cg', C1', C2', and C3' can satisfy one or more of the following conditions: Cg'≧1.1*C3', Cg'≧2.0*C1', and C2'≧1.3*Cg'. That is, they can satisfy one or two of the following conditions: Cg'≧1.1*C3', Cg'≧2.0*C1', and C2'≧1.3*Cg', or they can satisfy all of the following conditions: Cg'≧1.1*C3', Cg'≧2.0*C1', and C2'≧1.3*Cg'.

[0042] In one embodiment, the number of first crystal grains 13 can be 5% or more and 50% or less of the total number of crystal grains.

[0043] If the number proportion of the first crystal grain 13 is less than 5%, it is difficult to incorporate a secondary phase containing Sn, rare earth elements, and liquid phase elements at the grain boundaries, which may result in insufficient grain boundary resistance.

[0044] On the other hand, if the number proportion of the first crystal grain 13 exceeds 50%, grain growth may be excessively suppressed, potentially leading to a decrease in dielectric constant, and it may be difficult to secure a dielectric constant of 2600 or higher.

[0045] On the other hand, there is no particular need to limit the method for controlling the number ratio of the first crystal grains 13. For example, when using a dielectric composition containing a BaTiO3-based dielectric powder having a core-shell structure, with a Sn content in the shell of 0.5 mol% or more and 2.0 mol% or less, and a size of 70 nm or less, the number ratio of the first crystal grains 13 can be more easily controlled to 5% or more and 50% or less. When using a dielectric powder in which the size of the BaTiO3-based dielectric powder exceeds 70 nm and the Sn content in the shell exceeds 2.0 mol%, the proportion of the first crystal grains may become excessively high.

[0046] In one embodiment, referring to Figure 7, the plurality of crystal grains may include at least one second crystal grain 12, and the second crystal grain 12 has a core-shell structure including a core 12a and a shell 12b surrounding the core, and when the average Sn content of the core and shell of the second crystal grain is defined as C4 and C5, respectively, the condition Cg > C5 > C4 can be satisfied.

[0047] Furthermore, the above Cg, C4, and C5 can satisfy the conditions Cg ≥ 1.1 * C5 and Cg ≥ 2.0 * C4.

[0048] Unlike the first crystal grain 11, the shell 12b of the second crystal grain 12 does not have a first region with a Sn content higher than that of the grain boundary. The Sn content of the shell 12b of the second crystal grain 12 can be similar to that of the second region 11b2 of the shell of the first crystal grain, and the ratio of Sn content to that of the core or grain boundary can also be similar to that of the second region 11b2 of the shell of the first crystal grain.

[0049] Furthermore, the plurality of crystal grains may include at least one third crystal grain 13, and the third crystal grain 13 may have Sn uniformly distributed throughout its interior.

[0050] In one embodiment, the plurality of crystal grains may contain BaTiO3 as the main component.

[0051] Furthermore, in addition to the aforementioned Sn, rare earth elements, and liquid phase elements, the material may contain at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn as a minor component, and at least one of Zr, Al, Mg, and Ca as a minor component.

[0052] Such additional components can be added to the base material powder or added in a form coated onto the base material powder.

[0053] On the other hand, the thickness (td) of the dielectric layer 111 does not need to be particularly limited.

[0054] However, when the dielectric layer is formed thinly with a thickness of less than 0.6 μm, in particular when the thickness of the dielectric layer is 0.4 μm or less, reliability may be reduced.

[0055] As described above, according to one embodiment of the present invention, by including a secondary phase containing Sn, rare earth elements, and liquid phase elements in the grain boundary 14, the grain boundary resistance can be increased and reliability can be improved, so that excellent reliability can be ensured even when the thickness of the dielectric layer 111 is 0.4 μm or less.

[0056] Therefore, when the thickness of the dielectric layer 111 is 0.4 μm or less, the reliability improvement effect due to grain boundary resistance enhancement of the present invention can become more pronounced.

[0057] The thickness (td) of the dielectric layer 111 can represent the average thickness of the dielectric layer 111 arranged between the first and second internal electrodes 121 and 122.

[0058] The average thickness of the dielectric layer 111 can be measured by scanning an image of the cross-section of the main body 110 in the length and thickness direction (LT) using a scanning electron microscope (SEM).

[0059] For example, the thickness of any dielectric layer extracted from an image obtained by scanning the cross-sections in the first and second directions (length and thickness directions) of the main body 110, which has been cut in the center of the third direction (width direction), using a scanning electron microscope (SEM), can be measured at 30 equally spaced points in the length direction, and the average value can be calculated.

[0060] The thickness measured at the 30 equally spaced points mentioned above can be measured in the capacitance forming region (Ac), which represents the area where the first and second internal electrodes 121 and 122 overlap each other.

[0061] The main body 110 includes a capacitance forming portion (Ac) in which capacitance is formed, which includes a first internal electrode 121 and a second internal electrode 122 disposed inside the main body 110 and arranged facing each other with a dielectric layer 111 in between, and cover portions 112 and 113 formed on the upper and lower parts of the capacitance forming portion (Ac) in the first direction.

[0062] Furthermore, the capacitance forming portion (Ac) is a portion that contributes to the formation of the capacitance of the capacitor, and can be formed by repeatedly stacking a plurality of first and second internal electrodes 121 and 122 with a dielectric layer 111 in between.

[0063] The cover portions 112 and 113 may include an upper cover portion 112 positioned above the volume forming portion (Ac) in the first direction and a lower cover portion 113 positioned below the volume forming portion (Ac) in the first direction.

[0064] The upper cover portion 112 and the lower cover portion 113 described above can be formed by stacking a single dielectric layer or two or more dielectric layers in the thickness direction on the upper and lower surfaces of the capacitance forming portion (Ac), respectively, and can basically serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0065] The upper cover portion 112 and the lower cover portion 113 described above do not include internal electrodes and may contain the same material as the dielectric layer 111.

[0066] In other words, the upper cover portion 112 and the lower cover portion 113 may include a ceramic material, for example, a barium titanate (BaTiO3) based ceramic material.

[0067] On the other hand, the thickness of the cover portions 112 and 113 is not particularly limited. However, in order to more easily achieve miniaturization and high capacitance of ceramic electronic components, the thickness (tp) of the cover portions 112 and 113 can be 20 μm or less.

[0068] Furthermore, margin portions 114 and 115 can be arranged on the side surface of the volume forming portion (Ac).

[0069] The margin portions 114 and 115 may include a margin portion 114 located on the fifth surface 5 of the main body 110 and a margin portion 115 located on the sixth surface 6. That is, the margin portions 114 and 115 can be located on both sides of the ceramic main body 110 in the width direction.

[0070] As shown in Figure 3, the margin portions 114 and 115 can refer to the regions between the interface between both ends of the first and second internal electrodes 121 and 122 and the body 110 in a cross-section of the main body 110 cut in the width-thickness (WT) direction.

[0071] The margins 114 and 115 can essentially serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0072] The margin portions 114 and 115 can be formed by applying a conductive paste to the ceramic green sheet, except for the portion where the margin portion is formed, to form internal electrodes.

[0073] Furthermore, in order to suppress the step caused by the internal electrodes 121 and 122, the internal electrodes after lamination can be cut so that they are exposed on the fifth and sixth surfaces 5 and 6 of the main body, and then a single dielectric layer or two or more dielectric layers can be laminated in the width direction on both sides of the capacitance forming portion (Ac) to form margin portions 114 and 115.

[0074] The internal electrodes 121 and 122 are stacked alternately with the dielectric layer 111.

[0075] The internal electrodes 121 and 122 may include first and second internal electrodes 121 and 122. The first and second internal electrodes 121 and 122 are arranged alternately facing each other with the dielectric layer 111 constituting the main body 110 in between, and can be exposed on the third and fourth surfaces 3 and 4 of the main body 110, respectively.

[0076] Referring to Figure 2, the first internal electrode 121 is separated from the fourth surface 4 and exposed via the third surface 3, and the second internal electrode 122 is separated from the third surface 3 and exposed via the fourth surface 4.

[0077] In this case, the first and second internal electrodes 121 and 122 can be electrically isolated from each other by the dielectric layer 111 placed in between.

[0078] Referring to Figure 4, the main body 110 can be formed by alternately stacking ceramic green sheets printed with the first internal electrode 121 and ceramic green sheets printed with the second internal electrode 122, and then firing them.

[0079] The internal electrodes 121 and 122 may contain nickel (Ni). However, the material used to form the internal electrodes 121 and 122 is not particularly limited, and any material with excellent electrical conductivity can be used. For example, the internal electrodes 121 and 122 may contain one or more of the following: nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

[0080] Furthermore, the internal electrodes 121 and 122 can be formed by printing a conductive paste for internal electrodes containing one or more of the following on a ceramic green sheet: nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof. The printing method for the conductive paste for internal electrodes can be screen printing or gravure printing, and the present invention is not limited thereto.

[0081] On the other hand, the thickness (te) of the internal electrodes 121 and 122 does not need to be particularly limited.

[0082] However, when the internal electrode is formed thinly with a thickness of less than 0.6 μm, especially when the thickness of the internal electrode is 0.4 μm or less, reliability may be reduced.

[0083] As described above, according to one embodiment of the present invention, by including a secondary phase containing Sn, rare earth elements, and liquid phase elements in the grain boundary 14, the grain boundary resistance can be increased and reliability can be improved. Therefore, even when the thickness of the internal electrodes 121 and 122 is 0.4 μm or less, excellent reliability can be ensured.

[0084] Therefore, when the thickness of the internal electrodes 121 and 122 is 0.4 μm or less, the reliability improvement effect due to grain boundary resistance enhancement of the present invention can be more pronounced, and miniaturization and high capacitance of ceramic electronic components can be achieved more easily.

[0085] The thickness (te) of the internal electrodes 121 and 122 mentioned above can be said to represent the average thickness of the internal electrodes 121 and 122.

[0086] The average thickness of the internal electrodes 121 and 122 can be measured by scanning an image of the cross-section of the main body 110 in the length and thickness direction (LT) using a scanning electron microscope (SEM).

[0087] For example, the thickness of arbitrary first and second internal electrodes 121 and 122 extracted from images obtained by scanning the first and second cross-sections (length and thickness directions) of the main body 110, which have been cut in the center of the third direction (width direction), at 30 equally spaced points in the length direction, can be measured and the average value can be determined.

[0088] The 30 equally spaced points mentioned above can be measured in the capacitance forming region (Ac), which represents the area where the internal electrodes 121 and 122 overlap each other.

[0089] External electrodes 131 and 132 can be arranged on the third surface 3 and fourth surface 4 of the main body 110.

[0090] The external electrodes 131 and 132 are arranged on the third and fourth surfaces 3 and 4 of the main body 110, respectively, and may include first and second external electrodes 131 and 132 that are connected to first and second internal electrodes 121 and 122, respectively.

[0091] Referring to Figure 1, the external electrodes 131 and 132 can be positioned to cover both end faces of the side margin portions 114 and 115 in the second direction.

[0092] In this embodiment, a structure is described in which the ceramic electronic component 100 has two external electrodes 131 and 132. However, the number and shape of the external electrodes 131 and 132 can be changed depending on the shape of the internal electrodes 121 and 122 or for other purposes.

[0093] On the other hand, the external electrodes 131 and 132 can be formed using any material that has electrical conductivity, such as metal, and the specific material can be determined by considering electrical properties, structural stability, etc. Furthermore, they can have a multilayer structure.

[0094] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a placed on the main body 110, and plating layers 131b and 132b formed on the electrode layers 131a and 132a.

[0095] As a more specific example for electrode layers 131a and 132a, the electrode layers 131a and 132a can be firing electrodes containing a conductive metal and glass, or resin-based electrodes containing a conductive metal and resin.

[0096] Furthermore, the electrode layers 131a and 132a can be formed in a manner in which a fired electrode and a resin-based electrode are formed sequentially on the main body. Also, the electrode layers 131a and 132a can be formed by transferring a sheet containing a conductive metal onto the main body, or by transferring a sheet containing a conductive metal onto a fired electrode.

[0097] The conductive metal contained in the electrode layers 131a and 132a can be a material with excellent electrical conductivity, and is not particularly limited. For example, the conductive metal can be one or more of nickel (Ni), copper (Cu), and their alloys.

[0098] The plating layers 131b and 132b play a role in improving mounting characteristics. The types of plating layers 131b and 132b are not particularly limited and can be plating layers containing one or more of Ni, Sn, Pd, and their alloys, and can be formed in multiple layers.

[0099] As a more specific example for the plating layers 131b and 132b, the plating layers 131b and 132b can be Ni plating layers or Sn plating layers, and can be configured such that a Ni plating layer and an Sn plating layer are formed sequentially on the electrode layers 131a and 132a, or can be configured such that an Sn plating layer, a Ni plating layer, and an Sn plating layer are formed sequentially. Furthermore, the plating layers 131b and 132b can also include multiple Ni plating layers and / or multiple Sn plating layers.

[0100] There is no particular limit to the size of the ceramic electronic component 100.

[0101] However, in order to achieve both miniaturization and high capacitance simultaneously, it is necessary to reduce the thickness of the dielectric layer and internal electrodes and increase the number of layers. Therefore, the reliability and insulation resistance improvement effects of the present invention can be more pronounced in ceramic electronic components 100 having a size of 1005 (length × width, 1.0 mm × 0.5 mm) or less.

[0102] Therefore, considering manufacturing tolerances, external electrode size, etc., the reliability improvement effect of the present invention can be more pronounced when the length of the ceramic electronic component 100 is 1.1 mm or less and the width is 0.55 mm or less. Here, the length of the ceramic electronic component 100 refers to the size of the ceramic electronic component 100 in the second direction, and the width of the ceramic electronic component 100 refers to the size of the ceramic electronic component 100 in the third direction.

[0103] (Example of experiment) After preparing the dielectric composition, a conductive paste for internal electrodes containing Ni was applied to a ceramic green sheet containing the dielectric composition to form an internal electrode pattern. Subsequently, the ceramic green sheets with the internal electrode pattern formed on them were stacked to obtain a laminate, which was then cut into chip units and fired to prepare a prototype multilayer ceramic capacitor (Proto-type MLCC).

[0104] In the example of the invention, a dielectric composition was used that contained dielectric powder having a core-shell structure with a shell containing 2 moles of Sn per 100 moles of BaTiO3 and a core made of BaTiO3, with an average size of 70 nm.

[0105] In the comparative example, a dielectric composition containing BaTiO3 powder but without Sn was used.

[0106] A prototype multilayer ceramic capacitor (Proto-type MLCC) was cut in the first and second directions at the center of the third direction, and then an image was scanned using a STEM at the center of the first and second directions. Figure 8 shows an image of the cross-section of the dielectric layer of the inventive example scanned using a STEM (a), an image of the Sn element mapped using STEM-EDS (b), and an image of the Dy element mapped using STEM-EDS (c). Figure 9 shows an image of the cross-section of the dielectric layer of the comparative example scanned using a STEM (a), an image of the Sn element mapped using STEM-EDS (b), and an image of the Dy element mapped using STEM-EDS (c).

[0107] Referring to Figure 8, it was confirmed that Sn and Dy are present at the grain boundaries in the region indicated by the square. Furthermore, Si was also confirmed to be present at the grain boundaries. Therefore, it was confirmed that a Sn-Dy-Si secondary phase exists at the grain boundaries.

[0108] In contrast, in the case of Figure 9, it was confirmed that Dy is present at the grain boundary, but Sn is not.

[0109] The reliability of the inventive examples and comparative examples was evaluated by high-temperature accelerated lifetime testing.

[0110] In the high-temperature accelerated life test, 100 sample chips each of the inventive example and the comparative example were prepared. A voltage of 9.45V was applied at 105°C for 12 hours, and sample chips whose insulation resistance decreased to 1 / 10 or less of the initial value were judged to be defective.

[0111] In the comparative example, 22 out of 100 samples were determined to be defective. In contrast, in the inventive example, only 1 out of 100 samples was determined to be defective, demonstrating a significant improvement in reliability.

[0112] Although embodiments of the present invention have been described in detail above, the present invention is not limited by the embodiments described above and the accompanying drawings, but is limited by the claims provided. Therefore, within the scope of the technical idea of ​​the present invention as described in the claims, various forms of substitution, modification, and alteration are possible by persons with ordinary skill in the art, and these also fall within the scope of the present invention. For example, the embodiments of each of the following items also fall within the scope of the present invention. (Item 1) A main body including a dielectric layer and internal electrodes, The main body comprises an external electrode arranged thereon and connected to the internal electrode, The dielectric layer has a plurality of crystal grains and crystal grain boundaries arranged between adjacent crystal grains. The aforementioned grain boundary includes a secondary phase containing Sn, a rare earth element, and a first minor component. The aforementioned rare earth elements include one or more of the following: Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, Tb, Tm, La, Gd, and Yb. A ceramic electronic component wherein the first minor component contains one or more of Si, Mg, and Al. (Item 2) The ceramic electronic component described in item 1, wherein the elemental ratio of Sn, rare earth elements, and the first minor component contained in the secondary phase is Sn:rare earth elements:first minor component = 1:x:y, where x is between 0.01 and 10.0, and y is between 0.01 and 10.0. (Item 3) The ceramic electronic component described in item 1, wherein the rare earth element is Dy and the first minor component is Si. (Item 4) The plurality of crystal grains include at least one first crystal grain, The first crystal grain has a core-shell structure including a core and a shell surrounding the core, and the shell of the first crystal grain includes a first region surrounding the core and a second region surrounding the first region. When the average Sn content of the grain boundary is defined as Cg, and the average Sn content of the core, first region, and second region of the first grain are defined as C1, C2, and C3, respectively, A ceramic electronic component as described in item 1, satisfying the conditions C2 > Cg > C3 > C1. (Item 5) The aforementioned Cg, C1, C2, and C3 satisfy one or more of the following conditions: Cg ≥ 1.1 * C3, Cg ≥ 2.0 * C1, and C2 ≥ 1.3 * Cg, as described in item 4. (Item 6) When the average content of rare earth elements at the grain boundary is defined as Cg', and the average content of rare earth elements at the core, first region, and second region of the first grain is defined as C1', C2', and C3', respectively, A ceramic electronic component as described in item 4, satisfying the conditions C2'>Cg'>C3'>C1'. (Item 7) The ceramic electronic component described in item 6, wherein Cg', C1', C2', and C3' satisfy one or more of the following conditions: Cg'≧1.1*C3', Cg'≧2.0*C1', and C2'≧1.3*Cg'. (Item 8) A ceramic electronic component according to any one of items 4 to 7, wherein the number of the first crystal grains is 5% or more and 50% or less of the total number of the plurality of crystal grains. (Item 9) The plurality of crystal grains include at least one second crystal grain, The second crystal grain has a core-shell structure including a core and a shell surrounding the core. When the average Sn content of the core and shell of the second crystal grain is defined as C4 and C5, A ceramic electronic component described in any one of items 4 through 7, satisfying the conditions Cg > C5 > C4. (Item 10) The aforementioned Cg, C4, and C5 satisfy Cg ≥ 1.1 * C5 and Cg ≥ 3.0 * C4, and are ceramic electronic components as described in item 9. (Item 11) The plurality of crystal grains include at least one third crystal grain, The ceramic electronic component described in item 9, wherein Sn is uniformly distributed within the third crystal grain. (Item 12) The plurality of crystal grains are ceramic electronic components according to any one of items 1 to 7, with BaTiO3 as the main component. (Item 13) The ceramic electronic component according to any one of items 1 to 7, wherein the average thickness of the dielectric layer is 0.4 μm or less. (Item 14) The ceramic electronic component according to any one of items 1 to 7, wherein the average thickness of the internal electrodes is 0.4 μm or less. (Item 15) A main body including a dielectric layer and internal electrodes, The body includes an external electrode that is arranged on the main body and connected to the internal electrode, The dielectric layer includes a plurality of crystal grains and crystal grain boundaries arranged between adjacent crystal grains. The plurality of crystal grains include at least one first crystal grain, The first crystal grain has a core-shell structure including a core and a shell surrounding the core, and the shell of the first crystal grain includes a first region surrounding the core and a second region surrounding the first region. When the average Sn content of the grain boundary is defined as Cg, and the average Sn content of the core, first region, and second region of the first grain are defined as C1, C2, and C3, respectively, A ceramic electronic component that satisfies C2 > Cg > C3 > C1, and satisfies at least one of the following conditions: Cg ≥ 1.1 * C3, Cg ≥ 2.0 * C1, and C2 ≥ 1.3 * Cg. (Item 16) When the average content of rare earth elements at the grain boundary is defined as Cg', and the average content of rare earth elements at the core, first region, and second region of the first grain is defined as C1', C2', and C3', respectively, A ceramic electronic component as described in item 15, satisfying C2'>Cg'>C3'>C1' and one or more of the following: Cg'≧1.1*C3', Cg'≧2.0*C1', and C2'≧1.3*Cg'. (Item 17) The aforementioned grain boundary includes a secondary phase containing Sn, a rare earth element, and a first minor component. The aforementioned rare earth elements include one or more of the following: Y, Dy, Ho, Er, Gd, Ce, Nd, Sm, Tb, Tm, La, Gd, and Yb. The ceramic electronic component according to item 15 or 16, wherein the first minor component comprises one or more of Si, Mg, and Al. (Item 18) The secondary phase is Sn-Dy-Si, as described in item 17, for the ceramic electronic component. [Explanation of Symbols]

[0113] 100 Ceramic Electronic Components 110 Main Unit 111 Dielectric layer 11. First crystal grain 12. Second crystal grain 13. Third crystal grain 14. Grain boundaries 112, 113 Cover section 114, 115 Side margin section 121, 122 Internal electrode 131, 132 External electrode 131a, 132a electrode layer 131b, 132b Plating layer

Claims

1. A main body including a dielectric layer and internal electrodes, The main body comprises an external electrode arranged thereon and connected to the internal electrode, The dielectric layer includes a plurality of crystal grains and grain boundaries arranged between adjacent crystal grains. The aforementioned grain boundary contains Sn, a rare earth element, and a first minor component. The rare earth element comprises Dy, the first minor component comprises Si, and the plurality of crystal grains comprises BaTiO ３ A ceramic electronic component containing as its main component.

2. The ceramic electronic component according to claim 1, wherein when the elemental ratio of Sn, rare earth elements, and the first minor component contained in the grain boundary is Sn:rare earth elements:first minor component = 1:x:y, x is 0.01 or more and 10.0 or less, and y is 0.01 or more and 10.0 or less.

3. The ceramic electronic component according to claim 1, wherein the first minor component further comprises one or more of Mg and Al.

4. The plurality of crystal grains include at least one first crystal grain, The first crystal grain has a core-shell structure including a core and a shell surrounding the core, and the shell of the first crystal grain includes a first region surrounding the core and a second region surrounding the first region. The ceramic electronic component according to claim 1, wherein the average Sn content of the grain boundary is defined as Cg, and the average Sn content of the core, first region, and second region of the first crystal grain are defined as C1, C2, and C3, respectively, satisfying C2 > Cg > C3 > C1.

5. The ceramic electronic component according to claim 4, wherein Cg, C1, C2, and C3 satisfy one or more of the following conditions: Cg ≥ 1.1 * C3, Cg ≥ 2.0 * C1, and C2 ≥ 1.3 * Cg.

6. When the average content of rare earth elements at the grain boundaries is defined as Cg', and the average content of rare earth elements at the core, first region, and second region of the first grain is defined as C1', C2', and C3', respectively, A ceramic electronic component according to claim 4, satisfying C2' > Cg' > C3' > C1'.

7. The ceramic electronic component according to claim 6, wherein Cg', C1', C2', and C3' satisfy one or more of the following conditions: Cg' ≥ 1.1 * C3', Cg' ≥ 2.0 * C1', and C2' ≥ 1.3 * Cg'.

8. The ceramic electronic component according to claim 4, wherein the number of the first crystal grains is 5% or more and 50% or less of the total number of the plurality of crystal grains.

9. The plurality of crystal grains include at least one second crystal grain, The second crystal grain has a core-shell structure including a core and a shell surrounding the core. When the average Sn content of the core and shell of the second crystal grain is defined as C4 and C5, A ceramic electronic component according to claim 4, satisfying Cg > C5 > C4.

10. The ceramic electronic component according to claim 9, wherein Cg, C4, and C5 satisfy Cg ≥ 1.1 * C5 and Cg ≥ 3.0 * C4.

11. The plurality of crystal grains include at least one third crystal grain, The ceramic electronic component according to claim 9, wherein Sn is uniformly distributed within the third crystal grain.

12. The ceramic electronic component according to claim 1, wherein the average thickness of the dielectric layer is 0.4 μm or less.

13. The ceramic electronic component according to claim 1, wherein the average thickness of the internal electrodes is 0.4 μm or less.

14. The average thickness of the dielectric layer is 0.4 μm or less. The ceramic electronic component according to claim 1, wherein the average thickness of the internal electrodes is 0.4 μm or less.

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