Multilayer ceramic capacitor

Abstract

A multilayer ceramic capacitor may include a main body, comprising a first surface and a second surface which are opposite to each other in a first direction, a third surface and a fourth surface which are opposite to each other in a second direction which intersects with the first direction, and a fifth surface and a sixth surface which are opposite to each other in a third direction which intersects with both the first direction and the second direction, and the body includes a plurality of dielectric layers and a plurality of internal electrodes stacked in the third direction; and an outer electrode disposed on an outer side of the body, where the body may include an edge region in which the inner electrodes are not disposed, the edge region being disposed on an outer periphery of the plurality of inner electrodes facing the third surface and an outer periphery of the plurality of inner electrodes facing the fourth surface, a ratio of a width of the edge region to a width of the body measured in the second direction is greater than 8.5% and less than or equal to 9.5%, and wherein an average porosity of the edge region is greater than 0% and less than 1.1%.

Description

Technical Field

[0001] This disclosure relates to a multilayer ceramic capacitor. Background Technology

[0002] Electronic components using ceramic materials include capacitors, inductors, piezoelectric elements, varistors, and thermistors. Among ceramic electronic components, multilayer ceramic capacitors (MLCCs) are used in a variety of electronic devices due to their small size, high capacitance, and ease of installation.

[0003] A multilayer ceramic capacitor may include a body and external electrodes. The body comprises multiple dielectric layers and multiple internal electrodes, and the external electrodes are disposed on the outside of the body and connected to the internal electrodes. If moisture or hydrogen permeates into the edge region of the body, the moisture resistance reliability of the multilayer ceramic capacitor may deteriorate. Summary of the Invention

[0004] This disclosure aims to provide a multilayer ceramic capacitor that can prevent moisture-resistant reliability degradation.

[0005] A multilayer ceramic capacitor may include: a body comprising a first and a second surface opposed to each other in a first direction, a third and a fourth surface opposed to each other in a second direction intersecting the first direction, and a fifth and a sixth surface opposed to each other in a third direction intersecting both the first and second directions, and the body comprising a plurality of dielectric layers and a plurality of inner electrodes stacked in the third direction; and an outer electrode disposed outside the body, wherein the body may include an edge region on which the inner electrodes are not disposed, the edge region being disposed on the outer periphery of the plurality of inner electrodes facing the third surface and the outer periphery of the plurality of inner electrodes facing the fourth surface, wherein the ratio of the width of the edge region, measured along the second direction, to the width of the body is greater than 8.5% and less than or equal to 9.5%, and wherein the average porosity of the edge region is greater than 0% and less than 1.1%.

[0006] The edge region may include the same dielectric material as the rest of the body.

[0007] The plurality of internal electrodes may include a plurality of first internal electrodes and a plurality of second internal electrodes, wherein the first internal electrodes and the second internal electrodes are alternately arranged in the third direction and respectively led out to the first surface and the second surface.

[0008] The external electrode may include: a first external electrode disposed on the first surface and connected to the plurality of first internal electrodes; and a second external electrode disposed on the second surface and connected to the plurality of second internal electrodes.

[0009] The multilayer ceramic capacitor may also include a plating layer covering the outer electrode.

[0010] The coating may include a first layer covering the external electrode, a second layer covering the first layer, and a third layer covering the second layer.

[0011] The first layer may include nickel (Ni), the second layer may include copper (Cu), and the third layer may include tin (Sn).

[0012] According to the multilayer ceramic capacitor disclosed herein, moisture or hydrogen permeation can be prevented by adjusting the width and porosity of the edge region of the substrate, thereby preventing deterioration of moisture resistance reliability. Attached Figure Description

[0013] Figure 1 This is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment.

[0014] Figure 2 It is shown schematically. Figure 1 An exploded perspective view of the stacked structure of the main body of a multilayer ceramic capacitor.

[0015] Figure 3 It is shown schematically. Figure 1 A top view of the first internal electrode of a multilayer ceramic capacitor.

[0016] Figure 4 It is shown schematically. Figure 1 A top view of the second internal electrode of a multilayer ceramic capacitor.

[0017] Figure 5 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0018] Figure 6 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0019] <Explanation of reference numerals in the attached figures> 1000: Multilayer ceramic capacitor 110: Main Body 120: First electrode layer 130: Second electrode layer 200: First external electrode 300: Second external electrode 140: Dielectric layer 143: First Covering Layer 145: Second Covering Layer 150: First internal electrode 160: Second internal electrode 170: Edge Zone 180: First coating 190: Second coating. Detailed Implementation

[0020] In the following description, the present disclosure will be described more fully with reference to the accompanying drawings, which illustrate embodiments of the present disclosure. The drawings and description are intended to be illustrative rather than restrictive in nature. Throughout the specification, the same reference numerals denote the same elements. Additionally, some components are exaggerated, omitted, or abbreviated in the drawings, and the dimensions of the individual components do not reflect their actual dimensions.

[0021] The accompanying drawings are provided only to facilitate an understanding of the embodiments disclosed in this specification and should not be construed as limiting the spirit of the disclosure. It should be understood that this disclosure includes all modifications, equivalents, and alternatives without departing from the scope and spirit of the disclosure.

[0022] Ordinal terms such as "first," "second," etc., will be used only to describe the various constituent elements and will not be construed as limiting these constituent elements. These terms are used only to distinguish one constituent element from another.

[0023] It will be understood that when an element such as a layer, film, region, component, or substrate is referred to as being "on" or "above" another element, it may be directly on the other element, or there may be elements in between. In contrast, when an element is referred to as being "directly on" another element, there are no elements in between. Furthermore, in the specification, the terms "on" or "above" mean disposed above or below the object portion, and do not necessarily mean disposed on the upper side of the object portion in the opposite direction based on the direction of gravity.

[0024] Throughout this specification, it should be understood that the terms "comprising," "including," "having," or "configuration" indicate the presence of the features, quantities, steps, operations, constituent elements, components, or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, quantities, steps, operations, constituent elements, components, or combinations thereof. Unless expressly stated to the contrary, the words "comprising" and variations such as "including" or "having" will be understood to mean including the stated elements but excluding any other elements.

[0025] Furthermore, throughout the instruction manual, the phrase "in a plan view" or "on a plane" means viewing the target portion from the top, while the phrase "in a cross-sectional view" or "on a cross-section" means viewing the cross-section formed by vertically cutting the target portion from the side.

[0026] Furthermore, throughout the specification, the term "connection" can be used not only for situations where two or more elements are directly connected, but also for situations where two or more elements are indirectly connected through other elements, and for situations where two or more elements are physically or electrically connected. In addition, it can also be used for situations where two or more elements are referred to by different names based on their location or function, but are essentially one unit in practice.

[0027] Figure 1 This is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment.

[0028] Reference Figure 1 The multilayer ceramic capacitor 1000 according to this embodiment may include a main body 110, a first external electrode 200 and a second external electrode 300.

[0029] First, directions are defined to clearly describe this embodiment. The L-axis, W-axis, and T-axis directions shown in the accompanying drawings represent the length, width, and thickness directions of the multilayer ceramic capacitor 1000, respectively.

[0030] The thickness direction (T-axis direction) can be a direction perpendicular to the wide surface (main surface) of the sheet component. For example, the thickness direction (T-axis direction) can be used as the same concept as the direction of the stacked dielectric layer 140.

[0031] The length direction (L-axis direction) can be a direction parallel to the wide surface (main surface) of the sheet assembly, and can be a direction intersecting (or orthogonal / perpendicular) to the thickness direction (T-axis direction). For example, the length direction (L-axis direction) can be the direction in which the first external electrode 200 and the second external electrode 300 are opposite to each other.

[0032] The width direction (W-axis direction) can be a direction parallel to the wide surface (main surface) of the sheet component, and can be a direction that intersects (or is orthogonal / perpendicular) to both the thickness direction (T-axis direction) and the length direction (L-axis direction).

[0033] The body 110 may have a generally hexahedral shape, but this embodiment is not limited to this. Due to the shrinkage of the material included in the body 110 during sintering, the body 110 may not have a perfect hexahedral shape, but may have a generally hexahedral shape. For example, the body 110 may have a generally cuboid shape, but the portions corresponding to the edges or vertices of the body 110 may have a rounded shape.

[0034] In this embodiment, for ease of description, the surfaces of the body 110 that are opposite to each other in the length direction (L-axis direction) are defined as the first surface S1 and the second surface S2. The surfaces of the body 110 that are opposite to each other in the width direction (W-axis direction) and connect the first surface S1 and the second surface S2 can be defined as the third surface S3 and the fourth surface S4. The surfaces of the body 110 that are opposite to each other in the thickness direction (T-axis direction) and connect the first surface S1 and the second surface S2 can be defined as the fifth surface S5 and the sixth surface S6.

[0035] Therefore, the first direction in which the first surface S1 and the second surface S2 are opposite to each other can be the length direction (L-axis direction), and the second and third directions that are perpendicular to the first direction and perpendicular to each other can be the thickness direction (T-axis direction) and the width direction (W-axis direction), or the width direction (W-axis direction) and the thickness direction (T-axis direction), respectively.

[0036] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section taken at the center of the body 110 in the width direction (W-axis direction) along the length direction (L-axis direction) and thickness direction (T-axis direction), the length of the body 110 can be defined as the maximum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the length direction (L-axis direction). Alternatively, the length of the body 110 can be defined as the minimum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the length direction (L-axis direction). Alternatively, the length of the body 110 can be defined as the arithmetic mean of the dimensions of at least two line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the length direction (L-axis direction).

[0037] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section taken at the center of the body 110 in the width direction (W-axis direction) along the length direction (L-axis direction) and thickness direction (T-axis direction), the thickness of the body 110 can refer to the maximum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the thickness direction (T-axis direction). Alternatively, the thickness of the body 110 can refer to the minimum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the thickness direction (T-axis direction). Alternatively, the thickness of the body 110 can refer to the arithmetic mean of the dimensions of at least two line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the thickness direction (T-axis direction).

[0038] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section taken at the center of the body 110 in the thickness direction (T-axis direction) along the length direction (L-axis direction) and width direction (W-axis direction), the width of the body 110 can refer to the maximum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the width direction (W-axis direction). Alternatively, the width of the body 110 can refer to the minimum value among the dimensions of multiple line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the width direction (W-axis direction). Alternatively, the width of the body 110 can refer to the arithmetic mean of the dimensions of at least two line segments that connect the two outermost boundary lines of the body 110 shown in the cross-sectional photograph and are parallel to the width direction (W-axis direction).

[0039] Figure 2 It is shown schematically. Figure 1 An exploded perspective view of the stacked structure of the main body of a multilayer ceramic capacitor. Figure 3 It is shown schematically. Figure 1 A top view of the first internal electrode of a multilayer ceramic capacitor. Figure 4 It is shown schematically. Figure 1 A top view of the second internal electrode of a multilayer ceramic capacitor. Figure 5 It is along Figure 1 The cross-sectional view taken from line I-I'. Figure 6 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0040] Reference Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 ,the body 110 may include a plurality of dielectric layers 140, as well as a plurality of inner electrodes 150 and 160 (a first inner electrode 150 and a second inner electrode 160).

[0041] The plurality of dielectric layers 140 may be stacked in the thickness direction (T-axis direction). The boundary between adjacent dielectric layers 140 may not be clear. For example, without using a scanning electron microscope (SEM), it may be difficult to distinguish the boundary between adjacent dielectric layers 140, and the plurality of dielectric layers 140 may appear to be an integrated structure.

[0042] The dielectric layer 140 may include a ceramic material. For example, the ceramic material may include a dielectric ceramic having the following main components: such as at least one selected from the group consisting of BaTiO3, CaTiO3, SrTiO(3), and CaZrO3. In addition, in addition to the above main components, the ceramic material of the dielectric layer may further include secondary components, and the secondary components include: for example, at least one selected from the group consisting of manganese (Mn) compounds, iron (Fe) compounds, chromium (Cr) compounds, cobalt (Co) compounds, nickel (Ni) compounds, and combinations thereof. For example, the dielectric layer may include: (Ba 1-x Ca x )TiO3 (0 < x < 1), Ba(Ti 1-y Ca y )O3 (0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3 (0 < x < 1, 0 < y < 1), Ba(Ti 1-y Zr y )O3 (0 < y < 1), and combinations thereof, etc., selected from the group consisting of at least one, but the present disclosure is not limited thereto.

[0043] In addition, the dielectric layer 140 may further include one or more of a ceramic additive, an organic solvent, a plasticizer, an adhesive, and a dispersant. Examples of the ceramic additive may include: at least one selected from the group consisting of transition metal oxides or transition metal carbides, rare earth elements, magnesium (Mg), aluminum (Al), and combinations thereof.

[0044] The first inner electrode 150 and the second inner electrode 160 can be stacked alternately, and the dielectric layer 140 is located between the first inner electrode 150 and the second inner electrode 160. This stacking structure can be repeated inside the body 110, and the inner electrode of the fifth surface S5 closest to the body 110 and the inner electrode of the sixth surface S6 closest to the body 110 can be the first inner electrode 150 and the second inner electrode 160, respectively, or the inner electrode of the sixth surface S6 closest to the body 110 and the inner electrode of the fifth surface S5 closest to the body 110 can be the first inner electrode 150 and the second inner electrode 160, respectively.

[0045] The first inner electrode 150 and the second inner electrode 160 have different polarities and can be electrically insulated from each other by a dielectric layer 140 disposed between them.

[0046] The first inner electrode 150 and the second inner electrode 160 can be formed by printing a conductive paste comprising metal for forming the inner electrodes onto the surface of the dielectric layer 140. For example, a conductive paste comprising nickel (Ni) or a nickel (Ni) alloy can be printed onto the surface of the dielectric layer to form the inner electrodes using screen printing or gravure printing. However, the embodiments are not limited to this.

[0047] When a voltage is applied to the first external electrode 200 and the second external electrode 300, charge accumulates between the first internal electrode 150 and the second internal electrode 160. That is, capacitance can be generated between the first internal electrode 150, which is electrically connected to the first external electrode 200, and the second internal electrode 160, which is electrically connected to the second external electrode 300. The capacitance of the multilayer ceramic capacitor 1000 is proportional to the area of ​​the first internal electrode 150 and the second internal electrode 160 overlapping each other along the thickness direction (T-axis direction).

[0048] In other words, the multilayer ceramic capacitor 1000 may include an active region AR and an edge region 170.

[0049] The effective region AR can be the area where the first inner electrode 150 and the second inner electrode 160 overlap along the thickness direction (T-axis direction).

[0050] The edge region 170 may include areas where the inner electrodes 150 and 160 are not provided.

[0051] For example, edge region 170 may be a region comprising the same material as that forming dielectric layer 140 but without the inner electrodes 150 and 160. In other words, edge region 170 may comprise the same dielectric material as the rest of the body 110.

[0052] Edge region 170 may include a width-direction edge region 170W and a length-direction edge region 170L. Specifically, edge region 170 may include a region where neither the first inner electrode 150 nor the second inner electrode 160 is disposed (e.g., width-direction edge region 170W), and may also include a region where neither the first inner electrode 150 nor the second inner electrode 160 is disposed (e.g., length-direction edge region 170L).

[0053] The length-direction edge region 170L may include a first edge region 171 and a second edge region 172. The first edge region 171 may be the region between the effective region AR and the first surface S1 of the body 110, and the second edge region 172 may refer to the region between the effective region AR and the second surface S2 of the body 110.

[0054] The width-direction edge region 170W may include a third edge region 173 and a fourth edge region 174. The third edge region 173 may be the region between the effective region AR and the third surface S3 of the body 110, and the fourth edge region 174 may refer to the region between the effective region AR and the fourth surface S4 of the body 110.

[0055] Reference Figure 6 The main body 110 has a width W1, the third edge region 173 has a first edge width M1, and the fourth edge region 174 has a second edge width M2. That is, the width of the edge region 170W in the width direction can be the sum of the first edge width M1 and the second edge width M2 (M1+M2).

[0056] The ratio of the width (M1+M2) of the width region 170W in the width direction to the width W1 of the body 110 (hereinafter referred to as the "edge ratio") may be greater than 8.5% and less than or equal to 9.5%. In some embodiments, the edge ratio may be greater than 8.5%, 8.6%, 8.7%, 8.8%, 8.9%, 9%, 9.1%, 9.2%, 9.3%, or 9.4%, and / or the edge ratio may be less than or equal to 9.5%, 9.4%, 9.3%, 9.2%, 9.1%, 9%, 8.9%, 8.8%, 8.7%, or 8.6%.

[0057] If the edge ratio is 8.5% or less, the edge area in the width direction is relatively thin, and external moisture or hydrogen may easily penetrate, which may reduce the moisture resistance reliability of the multilayer ceramic capacitor.

[0058] If the edge ratio exceeds 9.5%, the effective area AR becomes relatively small, which may lead to a decrease in capacitance of the multilayer ceramic capacitor.

[0059] Here, the width (M1+M2) of the edge region 170W in the width direction can be measured based on an optical microscope or scanning electron microscope photograph of a cross-section taken at the center of the multilayer ceramic capacitor 1000 in the length direction (L-axis direction) along the width direction (W-axis direction) - thickness direction (T-axis direction). The first edge width M1 can be the arithmetic mean of the width of the third edge region 173 measured at the highest point in the thickness direction (T-axis direction) of the body 110 shown in the above cross-sectional photograph, the width of the third edge region 173 measured at the lowest point in the thickness direction (T-axis direction), and the width of the third edge region 173 measured at the center in the thickness direction (T-axis direction). In addition, the second edge width M2 can be the arithmetic mean of the width of the fourth edge region 174 measured at the highest point in the thickness direction (T-axis direction) of the main body 110 shown in the above cross-sectional photograph, the width of the fourth edge region 174 measured at the lowest point in the thickness direction (T-axis direction), and the width of the fourth edge region 174 measured at the center in the thickness direction (T-axis direction).

[0060] Additionally, the width-direction edge region 170W may have an average porosity greater than 0% and less than 1.1%. In some embodiments, the average porosity of the width-direction edge region 170W may be greater than 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%, and / or the average porosity of the width-direction edge region 170W may be less than 1.1%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1%.

[0061] If the average porosity of the 170W edge region in the width direction is 1.1% or greater, external moisture or hydrogen may easily permeate the edge region, which may reduce the moisture resistance reliability of the multilayer ceramic capacitor.

[0062] Here, the average porosity can be measured based on an optical microscope or scanning electron microscope image of a cross-section taken at the center of the multilayer ceramic capacitor 1000 along the width direction (W-axis) to the thickness direction (T-axis). For example, using image analysis software known in the art, a 10 μm × 10 μm region is selected from the highest point, lowest point, and center of the thickness direction (T-axis) of the edge region shown in the width direction of the cross-sectional image above. The porosity is obtained by measuring the area of ​​the selected region and the area of ​​the pores in the selected region, and then the arithmetic mean of these values ​​is calculated to obtain the average porosity.

[0063] For example, by controlling the amount of residual carbon during the calcination step of the dielectric green sheet laminate in the manufacturing process of a multilayer ceramic capacitor, the average porosity of the edge region in the width direction can be controlled to a certain range.

[0064] Reference Figure 5 and Figure 6 The main body 110 may include a first covering layer 143 and a second covering layer 145. The first covering layer 143 and the second covering layer 145 may be disposed on the upper and lower outer surfaces of the effective area AR in the thickness direction (T-axis direction).

[0065] The first cover layer 143 may be disposed between the fifth surface S5 of the main body 110 and the inner electrode closest to the fifth surface S5 of the main body 110. The second cover layer 145 may be disposed between the sixth surface S6 of the main body 110 and the inner electrode closest to the sixth surface S6 of the main body 110.

[0066] That is, within the body 110, a first cover layer 143 may be disposed above the uppermost inner electrode, and a second cover layer 145 may be disposed below the lowermost inner electrode. In some embodiments, the first cover layer 143 and the second cover layer 145 may have the same composition as the dielectric layer 140. The first cover layer 143 may be formed by stacking one or more dielectric layers on the outer surface of the uppermost inner electrode, and the second cover layer 145 may be formed by stacking one or more dielectric layers on the outer surface of the lowermost inner electrode. In another embodiment, the first cover layer 143 and the second cover layer 145 may have a different composition than the dielectric layer 140.

[0067] The first cover layer 143 and the second cover layer 145 can be used to prevent damage to the first inner electrode 150 and the second inner electrode 160 due to physical stress and / or chemical stress.

[0068] The first external electrode 200 and the second external electrode 300 can be disposed on the outer surface of the main body 110.

[0069] The first external electrode 200 may be disposed on the first surface S1 of the body 110 and may extend to the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. The second external electrode 300 may be disposed on the second surface S2 of the body 110 and may extend to the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. In another embodiment, the first external electrode 200 may extend to a portion of at least one of the fifth surface S5 and the sixth surface S6 of the body 110, and the second external electrode 300 may extend to a portion of at least one of the fifth surface S5 and the sixth surface S6 of the body 110.

[0070] The first external electrode 200 may include a first electrode layer 120 and a first plating layer 180.

[0071] The first electrode layer 120 may include a first connecting portion 121, a first strip portion 123, and a first corner portion 125.

[0072] The first connecting portion 121 can cover the first surface S1 of the main body 110 and is electrically connected to a plurality of first internal electrodes 150.

[0073] In another embodiment, the first connecting portion 121 may cover a portion of the first surface S1 of the body 110.

[0074] The first strip 123 may extend from the first connecting portion 121 to cover a portion of at least one of the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. For example, the first strip 123 may extend from the first connecting portion 121 to cover a portion of each of the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. The first strip 123 can ensure that the first electrode layer 120 adheres more firmly to the body 110.

[0075] The first corner portion 125 may be the portion that connects the first connecting portion 121 and the first belt portion 123.

[0076] The second external electrode 300 may include a second electrode layer 130 and a second plating layer 190.

[0077] The second electrode layer 130 may include a second connecting portion 131, a second strip portion 133, and a second corner portion 135.

[0078] The second connecting portion 131 can cover the second surface S2 of the main body 110 and is electrically connected to a plurality of second inner electrodes 160.

[0079] In another embodiment, the second connection portion 131 may cover a portion of the second surface S2 of the body 110.

[0080] The second strip 133 may extend from the second connecting portion 131 to cover a portion of at least one of the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. For example, the second strip 133 may extend from the second connecting portion 131 to cover a portion of each of the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the body 110. The second strip 133 can ensure that the second electrode layer 130 adheres more firmly to the body 110.

[0081] The second corner portion 135 may be the portion that connects the second connecting portion 131 and the second belt portion 133.

[0082] Based on optical microscope or scanning electron microscope (SEM) images of a cross-section taken at the center of the multilayer ceramic capacitor 1000 in the width direction (W-axis direction) along the length direction (L-axis direction) and thickness direction (T-axis direction), the first connecting portion 121 and the second connecting portion 131 shown in the cross-sectional images may have a shape substantially parallel to the thickness direction (T-axis direction), the first strip portion 123 and the second strip portion 133 may have a shape substantially parallel to the length direction (L-axis direction), and the first corner portion 125 and the second corner portion 135 may have a curved shape. The curved shape may have a tangent line whose slope gradually changes from a direction parallel to the thickness direction (T-axis direction) to a direction parallel to the length direction (L-axis direction) (or vice versa).

[0083] The first electrode layer 120 and the second electrode layer 130 may be formed using a conductive material, including, for example, at least one selected from the group consisting of copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti) and alloys thereof, but not limited thereto.

[0084] As another example, the first electrode layer 120 and the second electrode layer 130 may comprise metals and glass. For example, the metal may be a conductive metal selected from at least one of the following groups: copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof. The glass component contained in the electrode layers may be a mixture of oxides. The glass component may comprise, for example, at least one selected from the following groups: silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, alkaline earth metal oxide, and combinations thereof. Here, transition metals may be selected from the following groups: zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni); alkali metals may be selected from the following groups: lithium (Li), sodium (Na), and potassium (K); and alkaline earth metals may be selected from the following groups: magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). The method of forming the electrode layers is not particularly limited. For example, the electrode layer can be formed by immersing the subject in a conductive paste containing metal and glass, or by printing the conductive paste onto the surface of the subject using methods such as screen printing or gravure printing. Alternatively, various methods can be used, such as applying conductive paste to the surface of the subject or transferring a dry film formed by drying the conductive paste onto the subject.

[0085] The first plating layer 180 can cover the first electrode layer 120, and the second plating layer 190 can cover the second electrode layer 130.

[0086] Both the first plating layer 180 and the second plating layer 190 may include multiple layers. For example, the first plating layer 180 may include a first layer 181 covering the first electrode layer 120, a second layer 183 covering the first layer 181, and a third layer 185 covering the second layer 183. The first layer may include nickel (Ni), the second layer may include copper (Cu), and the third layer may include tin (Sn), but this embodiment is not limited thereto.

[0087] Furthermore, the second plating layer 190 may include a first layer 191 covering the second electrode layer 130, a second layer 193 covering the first layer 191, and a third layer 195 covering the second layer 193. The first layer 191 may include nickel (Ni), the second layer 193 may include copper (Cu), and the third layer 195 may include tin (Sn), but this embodiment is not limited thereto.

[0088] [Preparation Example: Fabrication of Multilayer Ceramic Capacitors] (Example 1) A paste containing barium titanate (BaTiO3) powder is applied to a carrier film and dried to produce multiple dielectric sheets.

[0089] A conductive paste, including nickel (Ni), is applied to a dielectric sheet using screen printing to form a conductive paste layer.

[0090] Multiple dielectric sheets are stacked such that at least a portion of the conductive paste layer overlaps each other to create a dielectric sheet stack.

[0091] After the dielectric sheet stack is cut into individual sheets, a first calcination (or degreasing) is performed by holding the individual sheets at 400°C for 70 hours in a nitrogen atmosphere, and a second calcination is performed by holding the individual sheets at 900°C for 6 hours in a hydrogen atmosphere.

[0092] The main body is manufactured by firing dielectric raw sheet stacks at 1165°C in a reducing atmosphere.

[0093] The outer electrode is formed by impregnating the outer surface of the body with a paste containing glass frit and copper (Cu), drying it, and then firing it.

[0094] Multilayer ceramic capacitors are manufactured by plating nickel (Ni) and tin (Sn) on the external electrodes and then heat-treating them at 160°C for 1 hour.

[0095] The manufactured multilayer ceramic capacitor has an edge ratio of 8.8% and an average porosity of 0.84% ​​in the width direction edge region.

[0096] (Example 2) The construction is the same as in Example 1, except that the edge ratio is 9.5% and the average porosity of the edge region in the width direction is 0.84%.

[0097] (Comparative Example 1) The construction is the same as in Example 1, except that the edge ratio is 8.3% and the average porosity of the edge region in the width direction is 1.35%.

[0098] (Comparative Example 2) The construction is the same as in Example 1, except that the edge ratio is 8.5% and the average porosity of the edge region in the width direction is 1.1%.

[0099] (Comparative Example 3) The construction is the same as in Example 1, except that the edge ratio is 9.6% and the average porosity of the edge region in the width direction is 1.1%.

[0100] [Experimental Example: Moisture Resistance Reliability of Multilayer Ceramic Capacitors] After manufacturing one hundred (100) multilayer ceramic capacitors according to Examples 1 and 2 and Comparative Examples 1 to 3, respectively, the moisture resistance reliability was measured.

[0101] Solder paste was patterned on a 40-channel moisture-resistant printed circuit board (PCB) substrate using a cutout mask. A reflow soldering process was then performed at a maximum temperature of 260°C, and the prepared samples were mounted on the PCB substrate. The prepared PCB substrate was mounted in a tank capable of measuring potential difference and current, and placed in a chamber at a temperature of 85°C and a humidity of 85%RH (relative humidity). Subsequently, the level of insulation resistance (IR) degradation was examined to measure moisture resistance reliability in a first step of applying a potential difference of 7.56V across the sample for 1 hour, a second step of 1 hour, and a third step of applying a potential difference of 4.5V across the sample for 2 hours. Multilayer ceramic capacitors with an IR that could not be measured were considered "defective," with an IR of 10. 6 Multilayer ceramic capacitors with a capacitance below Ω are considered "degraded".

[0102] The number of samples with defects in moisture resistance and the number of samples with deteriorated insulation resistance were counted out of 100 samples each.

[0103] The results are summarized in Table 1.

[0104] (Table 1)

[0105] Referring to Table 1, the multilayer ceramic capacitors according to Examples 1 and 2 did not exhibit defects in moisture resistance reliability or insulation resistance degradation, while the multilayer ceramic capacitors according to Comparative Examples 1 to 3 exhibited defects in moisture resistance reliability and / or insulation resistance degradation. This appears to be because, in the cases of Comparative Examples 1 to 3, the edge ratio was relatively small or the average porosity was relatively high, which allowed external moisture or hydrogen to permeate.

[0106] While this disclosure has been described in conjunction with embodiments now considered practical, it should be understood that this disclosure is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalents included within the spirit and scope of the appended claims.

Claims

1. A multilayer ceramic capacitor, comprising: The body includes a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface opposite to each other in a second direction intersecting the first direction, and a fifth surface and a sixth surface opposite to each other in a third direction intersecting both the first direction and the second direction, and the body includes a plurality of dielectric layers and a plurality of internal electrodes stacked in the third direction. as well as External electrodes are disposed on the outer surface of the main body. The main body includes an edge region where no inner electrodes are disposed. This edge region includes the area between the outer periphery of the plurality of inner electrodes and the third surface, and the area between the outer periphery of the plurality of inner electrodes and the fourth surface. Wherein, the ratio of the width of the edge region measured along the second direction to the width of the body is greater than 8.5% and less than or equal to 9.5%, and The average porosity of the edge region is greater than 0% and less than 1.1%.

2. The multilayer ceramic capacitor according to claim 1, wherein, The edge region comprises the same dielectric material as the rest of the body.

3. The multilayer ceramic capacitor according to claim 1, wherein, The plurality of internal electrodes includes a plurality of first internal electrodes and a plurality of second internal electrodes, wherein the first internal electrodes and the second internal electrodes are alternately arranged in the third direction and respectively led out to the first surface and the second surface.

4. The multilayer ceramic capacitor according to claim 3, wherein, The external electrode includes: A first external electrode is disposed on the first surface and connected to the plurality of first internal electrodes; and The second external electrode is disposed on the second surface and connected to the plurality of second internal electrodes.

5. The multilayer ceramic capacitor according to claim 1, wherein the multilayer ceramic capacitor further comprises: A coating is applied to cover the outer electrode.

6. The multilayer ceramic capacitor according to claim 5, wherein, The coating includes: The first layer covers the outer electrode; The second layer covers the first layer; and The third layer covers the second layer.

7. The multilayer ceramic capacitor according to claim 6, wherein, The first layer contains nickel.

8. The multilayer ceramic capacitor according to claim 6, wherein, The second layer contains copper.

9. The multilayer ceramic capacitor according to claim 6, wherein, The third layer contains tin.

10. The multilayer ceramic capacitor according to claim 6, wherein, The first layer contains nickel. The second layer comprises copper; and The third layer contains tin.

11. The multilayer ceramic capacitor according to claim 1, wherein, The average porosity of the edge region is greater than or equal to 0.84% ​​and less than 1.1%.

Images