KR20240108771A - Multilayered capacitor - Google Patents

Abstract

A capacitor body including a dielectric layer and an internal electrode, and an external electrode disposed on the outside of the capacitor body, wherein the external electrode includes a first layer connected to the internal electrode, covering a part of the first layer, exposing another part, and comprising a resin. It includes a second layer, a third layer covering the second layer and containing a resin and a conductive metal, and a fourth layer covering the first and third layers, and the area ratio of the resin included in the second layer is Disclosed is a multilayer capacitor having an area ratio greater than that of the resin contained in the third layer.

Description

Multilayered capacitor {MULTILAYERED CAPACITOR}

This description relates to multilayer capacitors.

With technological advancements in the automotive electrical equipment industry and the IT industry, demand for multilayer capacitors (MLCCs) that satisfy improved performance and strong reliability is increasing. In particular, the automotive electrical equipment industry requires reliability in environments with strong mechanical stress, and accordingly, demand for multilayer capacitors with a certain level of bending strength characteristics is increasing.

Multilayer capacitors use external electrodes made by mixing metal powder and binder and then sintering them. The sintered external electrode has the advantage of excellent electrical connectivity with the internal electrode, but has low ductility and is vulnerable to mechanical stress.

Therefore, in order to improve the mechanical reliability of the multilayer capacitor, a resin-based external electrode mixed with polymer resin and metal powder is applied to the outside of the sintered external electrode. Resin-based external electrodes have higher ductility than sintered external electrodes, improving the mechanical properties of the multilayer capacitor, but have the problem of lower electrical connectivity than sintered external electrodes.

The electrical properties of a resin-based external electrode can be improved by controlling the metal content in the resin. However, as the metal content increases in the resin-based external electrode, the ductility effect of the resin decreases, resulting in deterioration of bending strength. Therefore, the resin-based external electrode contains metal within a metal content range that does not deteriorate the bending strength. However, as the scope of application of multilayer capacitors in the automotive electrical parts industry expands, the level of reliability required is increasing, and there is a need to improve the characteristics of resin-based external electrodes.

One aspect of the present disclosure is that the ductility of the external electrode is increased to improve the bending strength, thereby facilitating stress relief when bending of the substrate occurs, and the adhesion between the sintered metal layer and the conductive resin layer of the external electrode is increased to improve the adhesion strength of the external electrode. , the plating layer of the external electrode is formed densely, improving moisture resistance reliability, and the sintered metal layer and the plating layer are directly connected, thereby providing a multilayer capacitor with improved electrical characteristics.

A multilayer capacitor according to one aspect includes a capacitor body including a dielectric layer and an internal electrode, and an external electrode disposed on the outside of the capacitor body, wherein the external electrode includes a first layer connected to the internal electrode, a portion of the first layer, and another layer. It includes a second layer that is partially exposed and includes a resin, a third layer that covers the second layer and includes a resin and a conductive metal, and a fourth layer that covers the first and third layers.

The capacitor body has first and second surfaces facing each other in the stacking direction of the dielectric layer and the internal electrode, third and fourth surfaces facing each other in the longitudinal direction, and fifth and sixth surfaces facing each other in the width direction. has

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction, the area ratio of the resin contained in the second layer is greater than the area ratio of the resin contained in the third layer.

The second layer may not be located on the second side.

The third layer may not be located on the second side.

The first layer can be located on the first side, second side, and third side.

The second layer may be located on the first and third sides.

The third layer may be located on the first and third sides.

The fourth layer may be located on the first, second, and third sides.

The first to fourth layers may be located on the fifth and sixth sides.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the stacking direction length of the second layer on the third or fourth side is less than or equal to the stacking direction length of the first layer. You can.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the width direction center of the multilayer capacitor, the stacking direction length of the third layer on the third or fourth side is less than or equal to the stacking direction length of the first layer. You can.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the stacking direction length of the second layer on the third or fourth side is 95% or less of the stacking direction length of the first layer. You can.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the stacking direction length of the third layer on the third or fourth side is 95% or less of the stacking direction length of the first layer. You can.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the stacking direction length of the third layer on the third or fourth side is greater than or equal to the stacking direction length of the second layer. You can.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the second layer may be arranged to completely cover the first layer on the first side.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the third layer may be arranged to completely cover the first layer on the first side.

On the first side, the third layer may be disposed to completely cover the second layer, or on the first side, the third layer may be disposed to expose a portion of the second layer without covering the entire second layer.

On the first side, the second layer may be arranged to completely cover the first layer.

On the first side, the third layer may be disposed to expose a portion of the second layer without completely covering it.

On the first side, the fourth layer may be disposed to expose a portion of the second layer without covering the entire second layer.

The second layer may further include a non-conductive filler.

Non-conductive fillers may include silica, glass-based oxides, or combinations thereof.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the area ratio of the resin contained in the unit area of the second layer to the unit area of the second layer may be 100% to 60%. there is.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the area ratio of the resin contained in the unit area of the third layer to the unit area of the third layer may be 60% to 8%. there is.

The second layer may or may not further include a conductive metal.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the area ratio of the conductive metal included in the second layer may be smaller than the area ratio of the resin included in the second layer.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the area ratio of the conductive metal included in the third layer may be greater than the area ratio of the resin included in the third layer.

In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor, the maximum length in the longitudinal direction of the second layer on the third or fourth side may be 3 ㎛ or more.

A method of manufacturing a multilayer capacitor according to another aspect includes manufacturing a capacitor body including a dielectric layer and an internal electrode, and forming an external electrode on the outside of the capacitor body. The step of forming the external electrode includes manufacturing a capacitor body including a dielectric layer and an internal electrode. forming a first layer on the outside of the layer, forming a second layer by applying a paste for forming a second layer containing a resin to cover part of the first layer and exposing the other part, forming a second layer using a resin and a conductive metal. It includes forming a third layer by applying a paste for forming a third layer to cover the second layer, and forming a fourth layer covering the first layer and the third layer.

The content of the resin contained in the paste for forming the second layer is greater than the content of the resin contained in the paste for forming the third layer.

In the paste for forming the second layer, the content of the resin relative to the total volume of the resin and the conductive metal may be 100% by volume to 60% by volume.

In the paste for forming the third layer, the content of the resin relative to the total volume of the resin and the conductive metal may be 60% by volume to 8% by volume.

In the paste for forming the second layer, the volume % of the conductive metal relative to the total volume of the resin and the conductive metal may be smaller than the volume % of the resin.

In the paste for forming the third layer, the volume % of the conductive metal relative to the total volume of the resin and the conductive metal may be greater than the volume % of the resin.

According to the multilayer capacitor according to one aspect, the ductility of the external electrode is increased and the bending strength is improved, thereby facilitating stress relief when bending of the substrate occurs, and the adhesion between the sintered metal layer and the conductive resin layer of the external electrode is increased, thereby increasing the adhesion strength of the external electrode. is improved, the plating layer of the external electrode is formed densely, improving moisture resistance reliability, and the sintered metal layer and the plating layer are directly connected to improve electrical properties.

1 is a plan view of a multilayer capacitor according to one side.
Figure 2 is another plan view of a multilayer capacitor according to one side.
Figure 3 is a side view of a multilayer capacitor according to one side.
Figure 4 is another side view of a multilayer capacitor according to one aspect.
Figure 5 is a cross-sectional view of a multilayer capacitor according to one side.
Figure 6 is another cross-sectional view of a multilayer capacitor according to one side.
Figure 7 is a cross-sectional view of a multilayer capacitor according to a modified example of one aspect.
Figure 8 is a cross-sectional view of a multilayer capacitor according to a modified example of one aspect.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and identical or similar components are given the same reference numerals throughout the specification. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to, connected to, or facing the other component, but with the other component intervening. It must be understood that it may exist. On the other hand, when a component is referred to as being “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

Throughout the specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. Therefore, when a part is said to "include" a certain component, this does not mean excluding other components, but may further include other components, unless specifically stated to the contrary.

FIG. 1 is a plan view of a multilayer capacitor according to one side, FIG. 2 is another plan view of the multilayer capacitor according to one side, FIG. 3 is a side view of the multilayer capacitor according to one side, and FIG. 4 is a plan view of the multilayer capacitor according to one side. It is another side view, FIG. 5 is a cross-sectional view of the multilayer capacitor according to one side, and FIG. 6 is another cross-sectional view of the multilayer capacitor according to one side.

When defining directions to clearly explain this embodiment, the L-axis, W-axis, and T-axis shown in the drawing represent the length direction, width direction, and thickness direction of the capacitor body 110, respectively. Here, the thickness direction (T-axis direction) may be a direction perpendicular to the wide surface (main surface) of the sheet-shaped components, and may be used as the same concept as the stacking direction in which the dielectric layers 111 are stacked, for example. The longitudinal direction (L-axis direction) may be a direction extending parallel to the wide surface (main surface) of the sheet-shaped components and may be approximately perpendicular to the thickness direction (T-axis direction). For example, first and the direction in which the second external electrodes 131 and 132 are located. The width direction (W-axis direction) extends parallel to the wide surface (main surface) of the sheet-shaped components and may be approximately perpendicular to the thickness direction (T-axis direction) and the longitudinal direction (L-axis direction). , the length of the sheet-shaped components in the longitudinal direction (L-axis direction) may be longer than the length in the width direction (W-axis direction).

Referring to FIGS. 1 to 6, the multilayer capacitor 100 according to the present embodiment includes a capacitor body 110, and first and It may include second external electrodes 131 and 132.

For example, the capacitor body 110 may have a roughly hexahedral shape.

In this embodiment, for convenience of explanation, the two surfaces opposing each other in the thickness direction (T-axis direction) of the capacitor body 110 are referred to as first and second surfaces 110a and 110b, and the first and second surfaces 110a , 110b), and the two surfaces opposing each other in the longitudinal direction (L-axis direction) are the third and fourth surfaces 110e, 110f, which are connected to the first and second surfaces 110a, 110b, and are connected to the third and fourth surfaces 110e, 110f. The two sides that are connected to the four sides (110e, 110f) and face each other in the width direction (W-axis direction) are defined as the fifth and sixth sides (110c, 110d).

For example, the first surface 110a, which is the lower surface, may be a surface facing the mounting direction. In addition, the first to sixth surfaces 110a, 110b, 110e, 110f, 110c, and 110d may be flat, but the present embodiment is not limited thereto, and for example, the first to sixth surfaces 110a, 110b, 110e, 110f, 110c, 110d) may be a curved surface with a convex central portion, and the edges at the boundaries of each surface may be rounded.

The shape and dimensions of the capacitor body 110 and the number of stacks of the dielectric layers 111 are not limited to those shown in the drawings of this embodiment.

The capacitor body 110 is made by stacking a plurality of dielectric layers 111 in the thickness direction (T-axis direction) and then firing them, with the plurality of dielectric layers 111 sandwiched between the dielectric layers 111 in the thickness direction (T-axis direction). It includes a plurality of first and second internal electrodes 121 and 122 arranged alternately. For example, the first and second internal electrodes 121 and 122 may have different polarities.

At this time, the boundaries between each adjacent dielectric layer 111 of the capacitor body 110 may be integrated to the extent that it is difficult to check without using a scanning electron microscope (SEM).

Additionally, the capacitor body 110 may include an active area and a cover area.

The active area is a part that contributes to forming the capacitance of the multilayer capacitor 100. For example, the active area may be an area where the first and second internal electrodes 121 and 122 stacked along the thickness direction (T-axis direction) overlap.

The cover area is a margin part and may be located on the first side 110a and the second side 110b of the active area in the thickness direction (T-axis direction). This cover area may be a single dielectric layer 111 or two or more dielectric layers 111 stacked on the upper and lower surfaces of the active area, respectively.

Additionally, the capacitor body 110 may further include a side cover area. The side cover area is a margin portion and may be located on the fifth and sixth sides 110c and 110d of the active area in the width direction (W-axis direction), respectively. When applying the conductive paste layer for forming internal electrodes on the surface of the dielectric green sheet, the conductive paste layer is applied to only a portion of the surface of the dielectric green sheet, and the conductive paste layer is applied to both sides of the surface of the dielectric green sheet. It can be formed by stacking uncoated dielectric green sheets and then firing them.

The cover area and the side cover area serve to prevent damage to the first and second internal electrodes 121 and 122 due to physical or chemical stress.

As an example, the dielectric layer 111 may include a ceramic material with high dielectric constant. For example, the ceramic material may include a dielectric ceramic containing ingredients such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , or CaZrO ₃ . Additionally, these components may further include auxiliary components such as Mn compounds, Fe compounds, Cr compounds, Co compounds, and Ni compounds. For example, (Ba _1-x Ca _x )TiO ₃ , Ba(Ti _1-y Ca _y )O ₃ , (Ba _1-x Ca _{x )} ( It may include Ti _1-y Zr _y )O ₃ or Ba(Ti _1-y Zr _y )O ₃ .

In addition, ceramic additives, organic solvents, plasticizers, binders, and dispersants may be further added to the dielectric layer 111 along with ceramic powder. Ceramic additives may include, for example, transition metal oxides, transition metal carbides, rare earth elements, magnesium (Mg), or aluminum (Al).

As an example, the average thickness of the dielectric layer 111 may be 0.5 ㎛ to 10 ㎛.

The first and second internal electrodes 121 and 122 are electrodes having different polarities, and are alternately arranged opposite to each other along the thickness direction (T-axis direction) with the dielectric layer 111 interposed therebetween, and one end of the capacitor body ( 110) may be exposed through the third and fourth sides 110e and 110f, respectively.

The first and second internal electrodes 121 and 122 may be electrically insulated from each other by the dielectric layer 111 disposed in the middle.

The ends of the first and second internal electrodes 121 and 122 alternately exposed through the third and fourth surfaces 110e and 110f of the capacitor body 110 are connected to the first and second external electrodes 131 and 132. Each may be connected and electrically connected.

The first and second internal electrodes 121 and 122 include a conductive metal, for example, a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy thereof, for example, an Ag-Pd alloy. You can.

Additionally, the first and second internal electrodes 121 and 122 may include dielectric particles of the same composition as the ceramic material included in the dielectric layer 111.

The first and second internal electrodes 121 and 122 may be formed using a conductive paste containing a conductive metal. The printing method of the conductive paste may use a screen printing method or a gravure printing method.

For example, the average thickness of the first and second internal electrodes 121 and 122 may be 0.1 ㎛ to 2 ㎛.

The first and second external electrodes 131 and 132 are provided with voltages of different polarities and may be electrically connected to exposed portions of the first and second internal electrodes 121 and 122, respectively.

According to the above configuration, when a predetermined voltage is applied to the first and second external electrodes 131 and 132, charges are accumulated between the first and second internal electrodes 121 and 122 facing each other. At this time, the capacitance of the multilayer capacitor 100 is proportional to the overlapped area of the first and second internal electrodes 121 and 122 that overlap each other along the T-axis direction in the active area.

The first and second external electrodes 131 and 132 may have first to fourth electrode portions 131a, 132a, 131b, 132b, 131c, 132c, 131e, and 132e, respectively. The first electrode portions 131a and 132a are disposed on the first surface 110a. The second electrode portions 131b and 132b are disposed on the second surface 110b. The third electrode portions 131c and 132c are disposed on a pair of fifth and sixth surfaces 110c and 110d. The fourth electrode portions 131e and 132e are disposed on the corresponding third and fourth surfaces 110e and 110f. That is, the first and second external electrodes 131 and 132 have first and second surfaces 110a and 110b, fifth and sixth surfaces 110c and 110d, and third or fourth surfaces 110e, respectively. It is arranged on five sides of 110f). Adjacent first to fourth electrode units 131a, 132a, 131b, 132b, 131c, 132c, 131e, and 132e are connected to each other at the corners of the capacitor body 110 and are electrically connected.

The fourth electrode portions 131e and 132e cover ends exposed to the third and fourth surfaces 110e and 110f of the first and second internal electrodes 121 and 122. The first and second internal electrodes 121 and 122 are directly connected to the fourth electrode portions 131e and 132e, and the first and second internal electrodes 121 and 122 are respectively connected to the first and second external electrodes ( 131, 132).

The first and second external electrodes 131 and 132 are respectively the first layer (1311 and 1321), the second layer (1312 and 1322), the third layer (1313 and 1323), and the fourth layer (1314 and 1324). has The fourth layers 1314 and 1324 constitute the outermost layers of the first and second external electrodes 131 and 132.

The first electrode portions 131a and 132a have first layers 1311 and 1321, second layers 1312 and 1322, third layers 1313 and 1323, and fourth layers 1314 and 1324. That is, the first electrode portions 131a and 132a have a four-layer structure. In the first electrode portions 131a and 132a, the entire first layer 1311 and 1321 may be covered with the second layer 1312 and 1322.

The second electrode portions 131b and 132b have first layers 1311 and 1321 and fourth layers 1314 and 1324, and do not have second layers 1312 and 1322 and third layers 1313 and 1323. . That is, the second electrode portions 131b and 132b have a two-layer structure.

The third electrode portions 131c and 132c have first regions 131c1 and 132c1 and second regions 131c2 and 132c2. The second areas 131c2 and 132c2 are located closer to the first surface 110a than the first areas 131c1 and 132c1. The first area (131c1, 132c1) has the first layer (1311, 1321) and the fourth layer (1314, 1324), and does not have the second layer (1312, 1322) and the third layer (1313, 1323). That is, the first regions 131c1 and 132c1 have a two-layer structure. The second areas 131c2 and 132c2 have first layers 1311 and 1321, second layers 1312 and 1322, third layers 1313 and 1323, and fourth layers 1314 and 1324. That is, the second regions 131c2 and 132c2 have a four-layer structure.

The fourth electrode portions 131e and 132e have first regions 131e1 and 132e1 and second regions 131e2 and 132e2. The second areas 131e2 and 132e2 are located closer to the first surface 110a than the first areas 131e1 and 132e1. The first area (131e1, 132e1) has the first layer (1311, 1321) and the fourth layer (1314, 1324), and does not have the second layer (1312, 1322) and the third layer (1313, 1323). That is, the first regions 131e1 and 132e1 have a two-layer structure. The second areas 131e2 and 132e2 have first layers 1311 and 1321, second layers 1312 and 1322, third layers 1313 and 1323, and fourth layers 1314 and 1324. That is, the second regions 131e2 and 132e2 have a four-layer structure.

The first layers 1311 and 1321 are in direct contact with the capacitor body 110 and are disposed on the third and fourth surfaces 110e and 110f of the capacitor body 110, respectively, to form the first and second internal electrodes 121, 122). The first layers 1311 and 1321 include the first electrode portions 131a and 132a, the second electrode portions 131b and 132b, the first regions 131c1 and 132c1 of the third electrode portions 131c and 132c, and the second electrode portions 131a and 132a, respectively. It is located in the areas 131c2 and 132c2, and the first areas 131e1 and 132e1 and the second areas 131e2 and 132e2 of the fourth electrode portions 131e and 132e. That is, the first layer (1311, 1321) includes the first side (110a), the second side (110b), the third side (110e), the fourth side (110f), the fifth side (110c), and the sixth side. It may be located at (110d). As an example, the first layers 1311 and 1321 may be sintered metal layers.

The second layers 1312 and 1322 are arranged to cover a portion of the first layer 1311 and 1321 and expose another portion. The second layers 1312 and 1322 are the first electrode portions 131a and 132a, the second regions 131c2 and 132c2 of the third electrode portions 131c and 132c, and the fourth electrode portions 131e and 132e. It is located in area 2 (131e2, 132e2). That is, the second layers 1312 and 1322 are not located on the second side 110b, but on the first side 110a, third side 110e, fourth side 110f, fifth side 110c, and may be located on the sixth surface 110d. As an example, the second layers 1312 and 1322 may be conductive resin layers.

The third layers 1313 and 1323 are arranged to cover all or part of the second layers 1312 and 1322. The third layers 1313 and 1323 are the first electrode portions 131a and 132a, the second regions 131c2 and 132c2 of the third electrode portions 131c and 132c, and the fourth electrode portions 131e and 132e. It is located in area 2 (131e2, 132e2). That is, the third layers 1313 and 1323 may not be located on the second side 110b, but may be located on the first side 110a, third side 110e, fourth side 110f, or fifth side 110c. ), and may be located on the sixth side (110d). For example, the third layers 1313 and 1323 may be conductive resin layers.

The fourth layers 1314 and 1324 are arranged to cover the entire area of the third layers 1313 and 1323 and the exposed first layers 1311 and 1321. The fourth layer (1314, 1324) includes the first electrode portions (131a, 132a), the second electrode portions (131b, 132b), the first regions (131c1, 132c1), and the second electrode portions (131c1, 132c) of the third electrode portions (131c, 132c). It is located in the areas 131c2 and 132c2, and the first areas 131e1 and 132e1 and the second areas 131e2 and 132e2 of the fourth electrode portions 131e and 132e. That is, the fourth layer (1314, 1324) is the first side (110a), the second side (110b), the third side (110e), the fourth side (110f), the fifth side (110c), and the sixth side. It may be located at (110d). As an example, the fourth layers 1314 and 1324 may be plating layers.

The first to fourth electrode portions 131a, 132a, 131b, 132b, 131c, 132c, 131e, and 132e may be integrally connected to the first layers 1311 and 1321, respectively. The second layers 1312 and 1322 of the first, third, and fourth electrode units 131a, 132a, 131c, 132c, 131e, and 132e, respectively, may be integrally connected. The first, third, and fourth electrode portions 131a, 132a, 131c, 132c, 131e, and 132e are provided, respectively, and the third layers 1313 and 1323 are integrally connected. The fourth layers 1314 and 1324 of the first to fourth electrode units 131a, 132a, 131b, 132b, 131c, 132c, 131e, and 132e, respectively, may be integrally connected.

Below, the length of each of the first to fourth layers (1311, 1321, 1312, 1322, 1313, 1323, 1314, 1324) is the center (1/2) of the width direction (W-axis direction) of the multilayer capacitor 100. Cross-sections (cross-sections in the L-axis direction and T-axis direction) cut in the longitudinal direction and in the stacking direction perpendicular to the width direction (W-axis direction) at the branch point are observed using a scanning electron microscope (SEM) or scanning transmission electron microscope (STEM). It can be analyzed by doing. SEM or STEM can measure at 5000x magnification. If there are multiple lengths of the first to fourth layers (1311, 1321, 1312, 1322, 1313, 1323, 1314, 1324) in the cross section, the maximum length among them is the first to fourth layers. It can be any length of (1311, 1321, 1312, 1322, 1313, 1323, 1314, 1324).

In addition, the area ratio of the resin or conductive metal of the second layers (1312, 1322) and the third layers (1313, 1323), and whether or not non-conductive fillers are included, can be determined through cross-sectional photographs obtained by cross-sectional observation using the SEM or STEM. It can be measured by analysis with an electron beam microanalyzer (EPMA). When performing component analysis using an electron beam microanalyzer (EPMA), an X-ray spectrometer such as an energy dispersive spectrometer (EDS) or a wavelength dispersive spectrometer (WDS) can be used. For example, when the cross sections of the first and second external electrodes 131 and 132 are observed using a reflected electron image of an SEM or a HAADF image of a STEM, the conductive metal having a metallic bond can be recognized as a bright part of the contrast. and non-metallic components such as resin or non-conductive fillers (including other voids and oxides) can be recognized as dark areas of contrast. Therefore, the areas of the resin and conductive metal of the second layers (1312, 1322) and the third layers (1313, 1323) are calculated as the ratio of the area of the area with bright contrast to the area of the entire measurement field of view, such as by binarizing the cross-sectional photograph. can do.

On the third surface 110e, the length of the second layers 1312 and 1322 in the stacking direction (T-axis direction) is less than or equal to the length of the first layers 1311 and 1321 in the stacking direction (T-axis direction). For example, on the third side 110e, the length of the second layers 1312 and 1322 in the stacking direction (T-axis direction) is 95% or less compared to the length of the first layers 1311 and 1321 in the stacking direction (T-axis direction). Or it may be 10% to 50%. Electrical connectivity when the length of the second layers 1312 and 1322 in the stacking direction (T-axis direction) on the third side 110e is greater than 95% of the length of the first layers 1311 and 1321 in the stacking direction (T-axis direction). This may deteriorate.

Additionally, on the third surface 110e, the length of the third layers 1313 and 1323 in the stacking direction is less than or equal to the length of the first layers 1311 and 1321 in the stacking direction. For example, on the third surface 110e, the length of the third layers 1313 and 1323 in the stacking direction (T-axis direction) is 95% or less compared to the length of the first layers 1311 and 1321 in the stacking direction (T-axis direction). Or it may be 10% to 50%. Electrical connectivity when the stacking direction (T-axis direction) length of the third layers (1313, 1323) on the third side (110e) is greater than 95% of the stacking direction (T-axis direction) length of the first layers (1311, 1321). This may deteriorate.

Figure 7 is a cross-sectional view of a multilayer capacitor 100 according to a modification of one aspect.

FIG. 6 shows a case where the stacking direction (T-axis direction) length of the second layers 1312 and 1322 on the third surface 110e is smaller than the stacking direction (T-axis direction) length of the first layers 1311 and 1321. 7, on the third side 110e, the length of the second layers 1312 and 1322 in the stacking direction (T-axis direction) is the same as the length of the first layers 1311 and 1321 in the stacking direction (T-axis direction). A case is shown.

In addition, in FIG. 6, when the stacking direction (T-axis direction) length of the third layers 1313 and 1323 on the third surface 110e is smaller than the stacking direction (T-axis direction) length of the first layers 1311 and 1321. is shown, and in FIG. 7, the length in the stacking direction (T-axis direction) of the third layers 1313 and 1323 on the third surface 110e is the length in the stacking direction (T-axis direction) of the first layers 1311 and 1321. A similar case is shown.

Since the bending strength characteristics are improved by the second layers 1312 and 1322, the thickness of the second layers 1312 and 1322 may be thicker than the third layers 1313 and 1323. For example, the longitudinal direction (L-axis direction) of the third surface 110e or the fourth surface 110f of the second layers 1312 and 1322 may be 3 ㎛ or more, or 5 ㎛ to 150 ㎛. If the length in the longitudinal direction (L-axis direction) of the third surface 110e of the second layers 1312 and 1322 is less than 3 ㎛, the degree of improvement in bending strength may be minimal. The third layers (1313, 1323) are used to ensure plating properties, and since this has nothing to do with thickness, it may be sufficient for the third layers (1313, 1323) to be thick enough to be evenly applied.

On the first side 110a, the longitudinal length of the second layers 1312 and 1322 is greater than or equal to the longitudinal length of the first layers 1311 and 1321. Accordingly, on the first surface 110a, the second layers 1312 and 1322 may be arranged to completely cover the first layers 1311 and 1321.

On the first side 110a, the longitudinal length of the third layers 1313 and 1323 is greater than or equal to the longitudinal length of the first layers 1311 and 1321. Accordingly, on the first surface 110a, the third layers 1313 and 1323 may be arranged to completely cover the first layers 1311 and 1321.

Meanwhile, on the first side 110a, the longitudinal length of the third layers 1313 and 1323 may be greater than or equal to the longitudinal length of the second layers 1312 and 1322. Accordingly, on the first surface 110a, the third layers 1313 and 1323 may be arranged to completely cover the second layers 1312 and 1322.

Alternatively, the longitudinal length of the second layers 1312 and 1322 may be greater than or equal to the longitudinal length of the third layers 1313 and 1323. Accordingly, on the first side 110a, the third layers 1313 and 1323 may be arranged to expose a portion of the second layers 1312 and 1322 without covering all of the second layers 1312 and 1322. .

FIG. 8 is a cross-sectional view of a multilayer capacitor 100 according to a modified example of one aspect.

6 and 7 illustrate a case where the longitudinal length of the third layers 1313 and 1323 is greater than the longitudinal length of the second layers 1312 and 1322 on the first surface 110a. Accordingly, on the first surface 110a, the third layers 1313 and 1323 may be arranged to completely cover the second layers 1312 and 1322.

Meanwhile, FIG. 8 shows a case where the longitudinal length of the second layers 1312 and 1322 is greater than the longitudinal length of the third layers 1313 and 1323 on the first surface 110a. In this case, on the first surface 110a, the second layers 1312 and 1322 are not entirely covered by the third layers 1313 and 1323, and the ends of the second layers 1312 and 1322 are exposed. If the second layers (1312, 1322) contain a conductive metal, the fourth layers (1314, 1324) may be disposed on the second layers (1312, 1322), but the second layers (1312, 1322) contain a conductive metal. If it is not included or is included in a small amount, the fourth layers 1314 and 1324 may not be placed on the second layers 1312 and 1322, and the second layers 1312 and 1322 may ultimately be exposed. That is, on the first side 110a, the longitudinal length of the second layers 1312 and 1322 is greater than or equal to the longitudinal length of the first layers 1311 and 1321, and the length of the third layers 1313 and 1323. The directional length may be smaller than the longitudinal length of the second layers 1312 and 1322, and the longitudinal length of the fourth layers 1314 and 1324 may be smaller than or equal to the longitudinal length of the second layers 1312 and 1322. In this case, the first layer (1311, 1321) is located at a location where stress is concentrated when the substrate is bent, making it possible to further improve the bending strength.

The first layers 1311 and 1321 may be sintered metal layers. The sintered metal layer may include conductive metal and glass.

For example, the sintered metal layer is a conductive metal such as copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), tin (Sn), tungsten (W), and titanium. (Ti), lead (Pb), an alloy thereof, or a combination thereof. For example, copper (Cu) may include a copper (Cu) alloy. When the conductive metal contains copper, metals other than copper may be included in an amount of 5 mole parts or less based on 100 mole parts of copper.

As an example, the sintered metal layer may include a mixture of glass and oxides, for example, one or more selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide. . The transition metal is selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni), and the alkali metal is lithium (Li). ), sodium (Na), and potassium (K), and the alkaline earth metal may be one or more selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

The content of conductive metal and glass in the sintered metal layer is not particularly limited, but for example, the length perpendicular to the width direction (W-axis direction) at the center (1/2 point) of the width direction (W-axis direction) of the multilayer capacitor 100 The area ratio of the conductive metal in a cross-section cut in the direction and stacking direction (cross-section in the L-axis direction and T-axis direction) may be 30% to 90%, or 70% to 90% of the unit area of the sintered metal layers (1311, 1321). .

The second layer (1312, 1322) or the third layer (1313, 1323) may be a conductive resin layer.

The conductive resin layer includes resin and conductive metal.

The resin included in the conductive resin layer is not particularly limited as long as it has bonding properties and shock absorption properties and can be mixed with conductive metal powder to make a paste, for example, phenolic resin, acrylic resin, silicone resin, epoxy resin, or polyimide. It may contain resin.

The conductive metal included in the conductive resin layer serves to electrically connect the first and second internal electrodes 121 and 122 or the sintered metal layer.

The conductive metal included in the conductive resin layer may have a spherical shape, a flake shape, or a combination thereof. That is, the conductive metal may be formed only in flake form, only in spherical form, or may be in a mixed form of flake form and spherical form.

Here, a sphere may also include a shape that is not a perfect sphere, for example, a shape in which the length ratio of the major axis and the minor axis (major axis/minor axis) is 1.45 or less. Flake-type powder refers to a powder with a flat and elongated shape, and is not particularly limited, but for example, the length ratio of the major axis to the minor axis (major axis/minor axis) may be 1.95 or more.

The conductive resin layer may include copper (Cu), silver (Ag), nickel (Ni), or a mixture thereof as a conductive metal. If the conductive resin layer contains silver (Ag), silver (Ag) dendrites may be formed on the surface of the multilayer capacitor 100 due to ion migration, so by using copper (Cu) By minimizing the amount of noble metal used in the first and second external electrodes 131 and 132, the occurrence of ion migration can be prevented or delayed.

Meanwhile, a cross section (L-axis direction and T-axis direction) cut in the longitudinal direction and the stacking direction perpendicular to the width direction (W-axis direction) at the center (half point) of the width direction (W-axis direction) of the multilayer capacitor 100 In the cross section), the area ratio (%) of the resin contained in the second layers (1312, 1322) and the area ratio (%) of the resin contained in the third layers (1313, 1323) are different.

As an example, a cross section (L-axis direction and T-axis) cut in the longitudinal direction and the stacking direction perpendicular to the width direction (W-axis direction) at the center (1/2 point) of the width direction (W-axis direction) of the multilayer capacitor 100. direction cross section), the area ratio of the resin included in the second layers 1312 and 1322 may be greater than the area ratio of the resin included in the third layers 1313 and 1323. That is, the content of the resin contained in the second layers 1312 and 1322 may be greater than the content of the resin contained in the third layers 1313 and 1323 disposed on the outside.

Here, the area ratio of the resin included in the second layer (1312, 1322) is the percentage of the area occupied by the resin included in the unit area of the second layer (1312, 1322) relative to the unit area of the second layer (1312, 1322). It may be (%), and the area ratio of the resin contained in the third layer (1313, 1323) is the resin contained in the unit area of the third layer (1313, 1323) relative to the unit area of the third layer (1313, 1323). It may be a percentage (%) of the area occupied.

In addition, the area ratio of the resin contained in the second layers (1312, 1322) is, for example, 10 ㎛ × 60 ㎛, or 30 ㎛ It can be measured within a unit area of 60 ㎛. The unit area may be located at any location within the second floor (1312, 1322), but the entire unit area must be located within the second floor (1312, 1322). For example, when measuring the area ratio of the resin contained in the second layers 1312 and 1322 on the third surface 110e, the long side of the unit area is parallel to the thickness direction (T-axis direction), and the short side of the unit area is parallel to the thickness direction (T-axis direction). It may be arranged parallel to the longitudinal direction (L-axis direction), and when measuring the area ratio of the resin contained in the second layers 1312 and 1322 on the first surface 110a, the long side of the unit area is in the longitudinal direction (L The short side of the unit area may be arranged parallel to the thickness direction (T-axis direction). At this time, the total area of the second layers 1312 and 1322 may be the total area of the unit area, and the area of the resin included in the second layers 1312 and 1322 may be the area of the resin located within the unit area.

Likewise, the area ratio of the resin contained in the third layer (1313, 1323) is, for example, 10 ㎛ × 60 ㎛, or 30 ㎛ × 30 ㎛ It can be measured within a unit area of 60 ㎛. The unit area may be located at any location within the third floor (1313, 1323), but the entire unit area must be located within the third floor (1313, 1323). For example, when measuring the area ratio of the resin contained in the third layers 1313 and 1323 on the third surface 110e, the long side of the unit area is parallel to the thickness direction (T-axis direction), and the short side of the unit area is parallel to the thickness direction (T-axis direction). It may be arranged parallel to the longitudinal direction (L-axis direction), and when measuring the area ratio of the resin contained in the third layer (1313, 1323) on the first surface (110a), the long side of the unit area is in the longitudinal direction (L The short side of the unit area may be arranged parallel to the thickness direction (T-axis direction). At this time, the total area of the third layer (1313, 1323) may be the total area of the unit area, and the area of the resin included in the third layer (1313, 1323) may be the area of the resin located within the unit area.

Methods for improving the bending strength of the multilayer capacitor 100 include relieving stress by improving the materials of the first and second external electrodes 131 and 132, or increasing the thickness of the conductive resin layer with a stress relieving function. There is a way to increase it. A method of improving the material of the first and second external electrodes 131 and 132 can be implemented by increasing the resin content in the conductive resin layer. However, due to the side effect that occurs when the resin content in the conductive resin layer increases, the resin content increases. There are restrictions. For example, when the resin content increases, the electrical connectivity of the multilayer capacitor 100 may deteriorate due to a decrease in the content of the conductive metal, and plating defects may occur due to an increase in the resin content, and plating defects and moisture permeability may occur. As the resin content increases, moisture resistance reliability may decrease.

Accordingly, the multilayer capacitor 100 according to this aspect has four lower surfaces of the multilayer capacitor 100, that is, the first surface (110a), the third surface (110e), the fourth surface (110f), and the fifth surface (110c). , and a conductive resin layer only on the sixth surface 110d, and includes two layers of conductive resin layers having different resin contents. Here, the lower four sides are areas that receive stress when mounted on the substrate and bending is applied to the substrate, and when the resin electrode is formed only on the lower four sides, there are five sides, that is, the first side 110a and the second side 110b. , the thickness of the conductive resin layer where bending stress is concentrated can be increased compared to the case where it is formed on the third side (110e), fourth side (110f), fifth side (110c), and sixth side (110d).

In addition, the second layers 1312 and 1322 disposed outside the first layers 1311 and 1321 increase the resin content to improve the bonding force and bending strength characteristics of the first and second external electrodes 131 and 132. , the reliability of the multilayer capacitor 100 can be improved by solving plating defects by lowering the resin content of the third layers 1313 and 1323 in contact with the fourth layers 1314 and 1324.

Accordingly, according to the multilayer capacitor 100 according to this aspect, the ductility of the first and second external electrodes 131 and 132 is increased and the bending strength is improved, so that stress relief when bending of the substrate occurs is easy, and the first and second external electrodes 131 and 132 are improved. The adhesion between the sintered metal layer and the conductive resin layer of the second external electrodes 131 and 132 is increased, so that the adhesion strength of the first and second external electrodes 131 and 132 is improved, and the adhesive strength of the first and second external electrodes 131 and 132 is improved. 132) The plating layer is formed densely, improving moisture resistance reliability, and the sintered metal layer and the plating layer are directly connected to improve electrical properties.

As an example, a cross section (L-axis direction and T-axis) cut in the longitudinal direction and the stacking direction perpendicular to the width direction (W-axis direction) at the center (1/2 point) of the width direction (W-axis direction) of the multilayer capacitor 100. In the direction cross section), the area ratio of the resin contained in the unit area of the second layers 1312 and 1322 relative to the unit area of the second layers 1312 and 1322 is 100% to 60%, for example, 70% to 90%. It can be. If the area ratio of the resin included in the second layer (1312, 1322) is less than 60%, the improvement in bending strength may be reduced. When the area ratio of the resin included in the second layers 1312 and 1322 is 100%, the second layers 1312 and 1322 do not contain conductive metal.

A cross-section (cross-section in the L-axis direction and T-axis direction) cut in the longitudinal and stacking directions perpendicular to the width direction (W-axis direction) from the center (half point) of the width direction (W-axis direction) of the multilayer capacitor 100. In, the area ratio of the conductive metal included in the unit area of the second layers (1312, 1322) relative to the unit area of the second layers (1312, 1322) is 0% to 40%, for example, may be 30% to 10%. there is. If the area ratio of the conductive metal included in the second layers 1312 and 1322 exceeds 40%, the improvement in bending strength may be reduced.

In addition, as the area ratio of the resin contained in the second layers (1312, 1322) is 60% or more, the area ratio of the conductive metal contained in the second layers (1312, 1322) is 60% or more. It may be smaller than the area ratio of the resin.

Optionally, the second layers 1312 and 1322 may further include non-conductive fillers.

Non-conductive fillers may include silica, glass-based oxides, or combinations thereof. The glass-based oxide may be, for example, one or more selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide. The transition metal is selected from the group consisting of zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), and nickel (Ni), and the alkali metal is lithium (Li). ), sodium (Na), and potassium (K), and the alkaline earth metal may be one or more selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

The content of the non-conductive filler in the second layers 1312 and 1322 is not particularly limited, but for example, the width direction (W-axis direction) is changed from the center (1/2 point) of the multilayer capacitor 100 in the width direction (W-axis direction). ), the area ratio of the non-conductive filler in the cross-section (L-axis direction and T-axis direction cross-section) cut perpendicular to the longitudinal direction and the stacking direction is 0% to 40%, or 10% of the unit area of the second layer (1312, 1322) It may be from % to 30%. If the content of non-conductive filler exceeds 40%, the improvement in bending strength may be reduced.

In addition, a cross-section (L-axis direction and T-axis direction) cut in the longitudinal direction and in the stacking direction perpendicular to the width direction (W-axis direction) at the center (half point) of the width direction (W-axis direction) of the multilayer capacitor 100. In the cross section), the area ratio of the resin contained in the unit area of the third layer (1313, 1323) relative to the unit area of the third layer (1313, 1323) is 60% to 8%, for example, 60% to 40%. You can. If the area ratio of the resin contained in the third layer (1313, 1323) is less than 8%, the resin and the conductive metal are not mixed evenly, making it difficult to manufacture the paste, and if it exceeds 60%, it may be difficult to prepare the paste on the third layer (1313, 1323). When forming the fourth layers 1314 and 1324 using a plating method, unplated areas may occur.

A cross-section (cross-section in the L-axis direction and T-axis direction) cut in the longitudinal direction and in the stacking direction perpendicular to the width direction (W-axis direction) at the center (half point) of the width direction (W-axis direction) of the multilayer capacitor 100. In, the area ratio of the conductive metal included in the unit area of the third layer (1313, 1323) relative to the unit area of the third layer (1313, 1323) is 92% to 40%, for example, may be 40% to 60%. there is. Accordingly, the area ratio of the conductive metal included in the third layers 1313 and 1323 may be greater than the area ratio of the resin included in the third layers 1313 and 1323.

The fourth layer (1314, 1324) may be a plating layer.

The plating layer is nickel (Ni), copper (Cu), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), or lead (Pb). ) may be included alone or alloys thereof. For example, the plating layer may be a nickel (Ni) plating layer or a tin (Sn) plating layer, and may be a sequential stacking of a nickel (Ni) plating layer and a tin (Sn) plating layer, and a tin (Sn) plating layer and a nickel (Ni) plating layer. ) The plating layer and the tin (Sn) plating layer may be sequentially laminated. Additionally, the plating layer may include a plurality of nickel (Ni) plating layers and/or a plurality of tin (Sn) plating layers.

The plating layer can improve mountability to the substrate, structural reliability, durability to the outside, heat resistance, and equivalent series resistance (ESR) of the multilayer capacitor 100.

A method of manufacturing a multilayer capacitor according to another embodiment includes manufacturing a capacitor body including a dielectric layer and an internal electrode, and forming an external electrode on the outside of the capacitor body.

First, the manufacturing of the capacitor body will be described. In the capacitor body manufacturing process, a dielectric paste that becomes a dielectric layer after firing and a conductive paste that becomes an internal electrode after firing are prepared.

Dielectric paste is manufactured in the following manner, for example. Calcined powder is obtained by uniformly mixing ceramic materials by means such as wet mixing, drying them, and then heat-treating them under predetermined conditions. An organic vehicle or an aqueous vehicle is added to the obtained calcined powder and kneaded to prepare a dielectric paste.

A dielectric green sheet is obtained by forming the obtained dielectric paste into a sheet using a technique such as the doctor blade method. Additionally, the dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, subcomponent compounds, or glass, if necessary.

The conductive paste for internal electrodes is prepared by mixing a conductive powder made of a conductive metal or an alloy thereof with a binder or solvent. The conductive paste for internal electrodes may, if necessary, contain ceramic powder (for example, barium titanate powder) as a co-material. The co-material may act to suppress sintering of the conductive powder during the firing process.

The conductive paste for internal electrodes is applied to the surface of the dielectric green sheet in a predetermined pattern using various printing methods such as screen printing or transfer methods. Then, the dielectric green sheets forming the internal electrode patterns are stacked in multiple layers and then pressed in the stacking direction to obtain a dielectric green sheet laminate. At this time, the dielectric green sheet and the internal electrode pattern may be stacked so that the dielectric green sheet is located on the upper and lower surfaces of the dielectric green sheet laminate in the stacking direction.

Optionally, the obtained dielectric green sheet laminate can be cut to a predetermined size by dicing or the like.

Additionally, the dielectric green sheet laminate can be solidified and dried to remove plasticizers, etc., if necessary, and after solidified and dried, it can be barrel polished using a horizontal centrifugal barrel machine, etc. In barrel polishing, the dielectric green sheet laminate, along with media and polishing liquid, is placed into a barrel container and rotational motion or vibration is applied to the barrel container, thereby polishing unnecessary parts such as burrs generated during cutting. . Additionally, after barrel polishing, the dielectric green sheet laminate can be washed with a cleaning solution such as water and dried.

The dielectric green sheet laminate is subjected to binder removal and firing to obtain a capacitor body.

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

The conditions of the firing treatment can be appropriately adjusted depending on the main component composition of the dielectric layer or the main component composition of the internal electrode. For example, the temperature during firing may be 1200°C to 1350°C, or 1220°C to 1300°C, and the time may be 0.5 hours to 8 hours, or 1 hour to 3 hours. The firing atmosphere may be a reducing atmosphere, for example, an atmosphere in which a mixed gas of nitrogen gas (N ₂ ) and hydrogen gas (H ₂ ) is humidified. When the internal electrode includes nickel (Ni) or a nickel (Ni) alloy, the oxygen partial pressure in the firing atmosphere may be 1.0 × 10 ^-14 MPa to 1.0 × 10 ^-10 MPa.

After the firing treatment, annealing can be performed as needed. Annealing is a treatment to reoxidize the dielectric layer, and when the firing treatment is performed in a reducing atmosphere, annealing can be performed. The conditions of the annealing treatment can also be appropriately adjusted depending on the main component composition of the dielectric layer. For example, the temperature during annealing may be 950°C to 1150°C, the time may be 0 to 20 hours, and the temperature increase rate may be 50°C/hour to 500°C/hour. The annealing atmosphere may be a humidified nitrogen gas (N ₂ ) atmosphere, and the oxygen partial pressure may be 1.0×10 ^-9 MPa to 1.0×10 ^-5 MPa.

In debinder treatment, firing treatment, or annealing treatment, for example, a wetter may be used to humidify nitrogen gas or mixed gas, and in this case, the water temperature may be 5°C to 75°C. The binder removal treatment, firing treatment, and annealing treatment can be performed sequentially or independently.

Optionally, the third and fourth sides of the obtained capacitor body may be subjected to surface treatment such as sand blasting, laser irradiation, or barrel polishing. By performing this surface treatment, the ends of the first and second internal electrodes can be exposed to the outermost surfaces of the third and fourth surfaces, and thus the ends of the first and second external electrodes and the first and second internal electrodes Electrical bonding becomes better, and alloy parts can be easily formed.

Optionally, the first layer forming paste may be applied to the outer surface of the obtained capacitor body and then sintered to form the first layer.

The paste for forming the first layer may include a conductive metal and glass. Since the description of the conductive metal and glass is the same as described above, repetitive description will be omitted. Additionally, the paste for forming the first layer may optionally include secondary ingredients such as a binder, solvent, dispersant, plasticizer, or oxide powder. For example, the binder can be ethylcellulose, acrylic, or butyral, and the solvent can be an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or an aqueous solvent. Solvents can be used.

The paste for forming the first layer can be applied to the outer surface of the capacitor body by using a dip method, various printing methods such as screen printing, an application method using a dispenser, or a spraying method using a spray. The sintered metal layer paste is applied to at least the third and fourth sides of the capacitor body, and optionally to the first, second, fifth, or sixth sides on which the band portions of the first and second external electrodes are formed. It can also be applied to some areas.

Thereafter, the capacitor body onto which the first layer forming paste is applied is dried and sintered at a temperature of 700°C to 1000°C for 0.1 to 3 hours to form the first layer.

The second layer can be formed by applying the second layer forming paste to the outer surface of the obtained capacitor body and then curing it.

The paste for forming the second layer may include a resin and, optionally, a conductive metal or a non-conductive filler. Since the description of the conductive metal and resin is the same as described above, repetitive description will be omitted. Additionally, the paste for forming the second layer may optionally include secondary ingredients such as a binder, solvent, dispersant, plasticizer, or oxide powder. For example, the binder can be ethylcellulose, acrylic, or butyral, and the solvent can be an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or an aqueous solvent. Solvents can be used.

For example, the method of forming the second layer includes forming the capacitor body 110 by dipping it in the paste for forming the second layer and then curing it, or by screen printing the paste for the conductive resin layer on the surface of the capacitor body 110. Alternatively, it can be formed by printing using a gravure printing method, or by applying the conductive resin layer paste to the surface of the capacitor body 110 and then curing it.

However, at this time, the paste for forming the second layer may be applied to cover part of the first layer and expose the other part. For example, the paste for forming the second layer is applied so that the second layer is not located on the second side, but is located on the first side, a part of the third side, a part of the fifth side, and a part of the sixth side. can do.

Next, the paste for forming the third layer can be applied on the second layer and then cured to form the third layer.

The paste for forming the third layer may contain a conductive metal and a resin. Since the description of the conductive metal and resin is the same as described above, repetitive description will be omitted. Additionally, the paste for forming the third layer may optionally include secondary ingredients such as a binder, solvent, dispersant, plasticizer, or oxide powder. For example, the binder can be ethylcellulose, acrylic, or butyral, and the solvent can be an organic solvent such as terpineol, butyl carbitol, alcohol, methyl ethyl ketone, acetone, or toluene, or an aqueous solvent. Solvents can be used.

As an example, the method of forming the third layer includes forming the capacitor body 110 by dipping it in the third layer forming paste and then curing it, or by screen printing the conductive resin layer paste on the surface of the capacitor body 110. Alternatively, it can be formed by printing using a gravure printing method, or by applying the conductive resin layer paste to the surface of the capacitor body 110 and then curing it.

However, at this time, the paste for forming the third layer may be applied to cover the second layer. For example, the third layer forming paste is applied so that the second layer is not located on the second side, but is located on the first side, a part of the third side, a part of the fifth side, and a part of the sixth side. can do.

At this time, the content of the resin included in the paste for forming the second layer may be greater than the content of the resin included in the paste for forming the third layer. Here, the content of the resin contained in the paste for forming the second layer may be a percentage (%) of the volume of the resin compared to the total volume of the resin and the conductive metal in the paste for forming the second layer, and may be included in the paste for forming the third layer. The content of the resin may be a percentage (%) of the volume of the resin compared to the total volume of the resin and the conductive metal in the paste for forming the third layer.

For example, in the paste for forming the second layer, the content of the resin relative to the total volume of the resin and the conductive metal may be 100% by volume to 60% by volume, for example, 70% by volume to 90% by volume. If the resin content in the paste for forming the second layer is less than 60% by volume, the improvement in bending strength may be reduced.

In the paste for forming the second layer, the content of the conductive metal relative to the total volume of the resin and the conductive metal may be smaller than the content of the resin. For example, in the paste for forming the second layer, the content of the conductive metal may be 0 vol% to 40 vol%, for example, 10 vol% to 30 vol%. If the content of the conductive metal in the paste for forming the second layer exceeds 40% by volume, the improvement in bending strength may be reduced.

For example, in the paste for forming the third layer, the content of the resin relative to the total volume of the resin and the conductive metal may be 60% by volume to 8% by volume, for example, 60% by volume to 40% by volume. If the resin content in the paste for forming the third layer is more than 60% by volume, electrical connectivity may be reduced, and if it is less than 8% by volume, moisture resistance reliability may be reduced.

In the paste for forming the third layer, the content of the conductive metal relative to the total volume of the resin and the conductive metal may be greater than the content of the resin. For example, in the paste for forming the third layer, the content of the conductive metal may be 92 vol% to 40 vol%, for example, 40 vol% to 60 vol%. If the content of the conductive metal in the paste for forming the third layer is less than 40% by volume, electrical connectivity may be reduced, and if it exceeds 92% by volume, moisture resistance reliability may be reduced.

Next, a fourth layer is formed outside the third layer.

For example, the fourth layer may be formed by a plating method, sputtering, or electrolytic plating (Electric Deposition).

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and can be implemented with various modifications within the scope of the claims, description of the invention, and accompanying drawings, which are also part of the present invention. It is natural that it falls within the scope.

100: Stacked capacitor
110: capacitor body
111: dielectric layer
121: first internal electrode
122: second internal electrode
131: first external electrode
132: second external electrode
1311, 1321: 1st floor
1312, 1322: 2nd floor
1313, 1323: 3rd floor
1314, 1324: 4th floor
110a, 110b: first and second sides
110e, 110f: 3rd and 4th sides
110c, 110d: 5th and 6th sides
131a, 132a: first electrode portion
131b, 132b: second electrode portion
131c, 132c: third electrode portion
131e, 132e: fourth electrode portion
131c1, 132c1: first area
131c2, 132c2: Second area
131e1, 132e1: First area
131e2, 132e2: Second area

Claims (19)

A capacitor body including a dielectric layer and an internal electrode, and
It includes an external electrode disposed outside the capacitor body,
The external electrode is a first layer connected to the internal electrode,
a second layer covering a part of the first layer and exposing another part and comprising a resin;
A third layer covering the second layer and comprising a resin and a conductive metal, and
It includes a fourth layer covering the first and third layers,
The capacitor body has first and second surfaces facing each other in the stacking direction of the dielectric layer and the internal electrode, a third surface and a fourth surface facing each other in the longitudinal direction, and a fifth surface facing each other in the width direction. With side 6,
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction, the area ratio of the resin contained in the second layer is greater than the area ratio of the resin contained in the third layer. In paragraph 1:
The second layer is not located on the second side,
A multilayer capacitor, wherein the third layer is not located on the second side. In paragraph 1:
The first layer is located on the first side, the second side, and the third side,
The second layer is located on the first side and the third side,
The third layer is located on the first side and the third side,
The fourth layer is located on the first surface, the second surface, and the third surface. In paragraph 3,
The first to fourth layers are located on the fifth and sixth surfaces. In paragraph 1:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
The stacking direction length of the second layer on the third or fourth surface is less than or equal to the stacking direction length of the first layer,
A multilayer capacitor wherein the stacking direction length of the third layer on the third or fourth surface is less than or equal to the stacking direction length of the first layer. In paragraph 1:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
The stacking direction length of the second layer on the third or fourth surface is 95% or less of the stacking direction length of the first layer,
A multilayer capacitor wherein the stacking direction length of the third layer on the third or fourth surface is 95% or less of the stacking direction length of the first layer. In paragraph 1:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
A multilayer capacitor wherein the stacking direction length of the third layer on the third or fourth surface is greater than or equal to the stacking direction length of the second layer. In paragraph 1:
On the first side, the second layer is disposed to completely cover the first layer,
On the first side, the third layer is arranged to completely cover the first layer,
Stacked capacitors. In paragraph 1:
On the first side, the third layer is arranged to completely cover the second layer, or on the first side, the third layer is arranged to expose a portion of the second layer without covering all of it,
Stacked capacitors. In paragraph 1:
On the first side, the second layer is disposed to completely cover the first layer,
On the first side, the third layer is disposed to expose a portion of the second layer without covering all of the second layer,
On the first side, the fourth layer is disposed to expose a portion of the second layer without covering all of the second layer.
Stacked capacitors. In paragraph 1:
The second layer further includes a non-conductive filler. In paragraph 11:
The non-conductive filler includes silica, glass-based oxide, or a combination thereof. In paragraph 1:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
The area ratio of the resin contained in the unit area of the second layer to the unit area of the second layer is 100% to 60%,
A multilayer capacitor wherein the area ratio of the resin contained in the unit area of the third layer to the unit area of the third layer is 60% to 8%. In paragraph 1:
The second layer may or may not further include a conductive metal. In paragraph 14:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
The area ratio of the conductive metal included in the second layer is smaller than the area ratio of the resin included in the second layer,
A multilayer capacitor wherein the area ratio of the conductive metal included in the third layer is greater than the area ratio of the resin included in the third layer. In paragraph 1:
In a cross section cut in the longitudinal direction and the stacking direction perpendicular to the width direction at the center of the width direction of the multilayer capacitor,
A multilayer capacitor wherein the maximum longitudinal length of the second layer on the third or fourth surface is 3 μm or more. manufacturing a capacitor body including a dielectric layer and an internal electrode, and
It includes forming an external electrode on the outside of the capacitor body,
The step of forming the external electrode is,
Forming a first layer on the outside of the capacitor body,
Forming a second layer by applying a paste for forming a second layer containing a resin to cover part of the first layer and expose the other part,
forming a third layer by applying a paste for forming a third layer containing a resin and a conductive metal to cover the second layer, and
Forming a fourth layer covering the first and third layers,
The content of the resin contained in the paste for forming the second layer is greater than the content of the resin contained in the paste for forming the third layer,
Manufacturing method of a multilayer capacitor. In paragraph 17:
In the paste for forming the second layer, the content of the resin relative to the total volume of the resin and the conductive metal is 100% by volume to 60% by volume,
In the paste for forming the third layer, the content of the resin relative to the total volume of the resin and the conductive metal is 60% to 8% by volume. In paragraph 17:
In the paste for forming the second layer, the volume % of the conductive metal relative to the total volume of the resin and the conductive metal is smaller than the volume % of the resin,
In the paste for forming the third layer, the volume % of the conductive metal relative to the total volume of the resin and the conductive metal is greater than the volume % of the resin.