Multilayer electronic component

Abstract

The present disclosure provides a multilayer electronic component including: a main body in which internal electrodes and dielectric layers are alternately disposed, the internal electrodes including Ni and Sn; and an external electrode disposed on a surface of the main body, connected to the internal electrodes, and including Cu and Sn, wherein the internal electrode includes an alloy including Ni, Cu, and Sn in a region in contact with the external electrode, and an amount of Sn satisfies a formula: 1 < C2 / C1 < 13.5, where C1 is a content of Sn of the internal electrode at a central portion of the main body, and C2 is a content of Sn of the internal electrode at a point 2 μm from a point at which the internal electrode and the external electrode contact each other in an inward direction of the main body.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0136191, filed with the Korean Intellectual Property Office on October 20, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to a multilayer electronic component. Background Technology

[0003] Multilayer ceramic capacitors (MLCCs) are chip capacitors mounted on printed circuit boards (PCBs) of various types of electronic products (such as display devices (including liquid crystal displays (LCDs), plasma display panels (PDPs)), computers, smartphones, cellular phones, etc.) for charging or discharging.

[0004] Multilayer ceramic capacitors (MLCCs), with advantages such as compactness, guaranteed high capacitance, and ease of installation, can be used as components in a variety of electronic devices. As various electronic devices (such as computers, mobile devices, etc.) become smaller and their power output increases, the demand for miniaturization and higher capacitance of multilayer ceramic capacitors is increasing.

[0005] Furthermore, with the recent increase in industry interest in electrical components for automobiles, there is a need for MLCCs to possess high reliability and high strength characteristics for use in automotive or infotainment systems.

[0006] Ni is primarily used as the internal electrode material in multilayer ceramic capacitors. However, when Ni is used alone as the internal electrode material, corrosion may occur in the area where the internal and external electrodes are in contact due to the plating solution introduced from the external electrode during plating, leading to wafer degradation. Summary of the Invention

[0007] An exemplary embodiment provides a multilayer electronic component with excellent moisture resistance and reliability.

[0008] An exemplary embodiment provides a multilayer electronic component that suppresses crack initiation.

[0009] An exemplary embodiment provides a multilayer electronic component with improved capacitance.

[0010] According to an exemplary embodiment, a multilayer electronic component includes: a main body, in which internal electrodes and dielectric layers are alternately disposed, the internal electrodes including Ni and Sn; and external electrodes disposed on a surface of the main body, connected to the internal electrodes, and including Cu and Sn, wherein a region of the internal electrode in contact with the external electrode includes an alloy containing Ni, Cu, and Sn (Ni-Cu-Sn alloy), and the amount of Sn satisfies the following formula: 1<C2 / C1<13.5, where C1 is a content (at%) of Sn included in the internal electrode at a central portion of the main body, and C2 is a content (at%) of Sn included in the internal electrode at a point 2 μm from a point where the internal electrode and the external electrode are in contact with each other in an inward direction of the main body, wherein the content of Sn is at% based on the total amount of components included in the internal electrode.

[0011] According to an exemplary embodiment, a multilayer electronic component includes: a main body, in which internal electrodes and dielectric layers are alternately disposed, the internal electrodes including Ni and Sn; and external electrodes disposed on a surface of the main body, connected to the internal electrodes, and including Cu and Sn, wherein the internal electrode includes: an alloy containing Ni, Cu, and Sn (Ni-Cu-Sn alloy), located in a region in contact with the external electrode; and 5 at% or more of Sn, located in a region having a length of 5 μm to 10 μm in an inward direction of the main body from a position where the internal electrode and the external electrode are in contact with each other.

[0012] According to an exemplary embodiment, a multilayer electronic component includes: a main body, in which internal electrodes and dielectric layers are alternately disposed; and external electrodes disposed on a surface of the main body, connected to the internal electrodes, and including Cu and Sn, wherein the internal electrode includes an alloy containing Cu and Sn, and an atomic percentage (at%) of each of Sn and Cu gradually decreases from a point where the internal electrode and the external electrode are in contact with each other in an inward direction of the main body. Brief Description of the Drawings

[0013] The above and other aspects, features and advantages of the present disclosure will be more clearly understood in conjunction with the accompanying drawings and the following detailed description, in which:

[0014] Figure 1 is a schematic perspective view of a multilayer electronic component according to an exemplary embodiment of the present disclosure.

[0015] Figure 2A is a Figure 1 cross-sectional view taken along line I-I' of

[0016] Figure 2B is a view illustrating Figure 2AA diagram showing the location of the element content of the internal electrode in the main body.

[0017] Figure 3 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0018] Figure 4 This is an exploded perspective view schematically illustrating a body in which a dielectric layer and an internal electrode are stacked, according to an exemplary embodiment of the present disclosure.

[0019] Figure 5A and Figure 5B Images of Cu and Ni elements were obtained using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) in the area where the inner and outer electrodes were in contact, when the outer electrode was formed using conductive paste without added Sn.

[0020] Figure 6A , Figure 6B and Figure 6C Images of Cu, Ni, and Sn elements were obtained using SEM-EDX in the region where the inner and outer electrodes were in contact, when the outer electrode was formed using an external electrode conductive paste with 5 wt% Sn added.

[0021] Figure 7A This is an image of the element Cu. Figure 7B This is an image of the Ni element. Figure 7C These are images of Sn elements, observed using SEM-EDX in the area where the inner and outer electrodes are in contact when the outer electrode is formed using an outer electrode conductive paste with 10 wt% Sn added.

[0022] Figure 8 It is a graph showing the at% of Cu, Ni and Sn elements of the inner electrode of a multilayer electronic assembly according to an exemplary embodiment of the present disclosure, based on the distance from the point where the inner electrode and the outer electrode contact each other in the inward direction of the body. Detailed Implementation

[0023] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0024] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be readily understood by those skilled in the art. The order of operations described herein is merely illustrative and is not limited to the order presented herein; changes that will be readily understood by those skilled in the art may be made, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of functions and constructions well-known to those skilled in the art may be omitted.

[0025] The features described herein may be implemented in various forms and are not to be construed as being limited to the examples described herein. Rather, the examples provided herein make this disclosure thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0026] It should be noted here that the use of the term "may" in relation to examples or embodiments (e.g., what an example or embodiment may include or implement) means that there exists at least one example or embodiment that includes or implements such a feature, and is not limited to all examples or embodiments that include or implement such a feature.

[0027] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected" to another element, or "bonded" to another element, the element may be directly "on" said other element, directly "connected" to said other element, or directly "bonded" to said other element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected" to another element, or "directly bonded" to another element, there are no other elements in between.

[0028] As used herein, the term "and / or" includes any one of the relevant listed items or any combination of any two or more items.

[0029] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts will not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part mentioned in the examples may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0030] For ease of description, spatial relative terms such as “above,” “above,” “below,” and “under” are used herein to describe the relationship between one element and another as shown in the accompanying drawings. Such spatial relative terms are intended to include not only the orientation depicted in the drawings but also the different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “above” relative to another element will be “below” or “under” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein will be interpreted accordingly.

[0031] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” enumerate the presence of the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0032] The shapes shown in the accompanying drawings may change due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but may include changes in shape that occur during manufacturing.

[0033] The features of the examples described herein can be combined in various ways as will be readily understood after understanding the disclosure of this application. Furthermore, while the examples described herein have multiple constructions, other constructions are possible as will be readily understood after understanding the disclosure of this application.

[0034] In the accompanying drawings, the X direction can be defined as a second direction, the L direction, or the length direction; the Y direction can be defined as a third direction, the W direction, or the width direction; and the Z direction can be defined as a first direction, the stacking direction, the T direction, or the thickness direction.

[0035] Multilayer electronic components

[0036] Figure 1 This is a schematic perspective view of a multilayer electronic assembly according to exemplary embodiments of the present disclosure.

[0037] Figure 2A It is along Figure 1 The cross-sectional view taken from line I-I'.

[0038] Figure 2B It is shown Figure 2A A diagram showing the location of the element content of the internal electrode in the main body.

[0039] Figure 3 is along Figure 1 a cross-sectional view taken along line II-II'.

[0040] Figure 4 is an exploded perspective view schematically illustrating a main body in which dielectric layers and internal electrodes are stacked according to an exemplary embodiment of the present disclosure.

[0041] Hereinafter, referring to Figures 1 to 4 a multilayer electronic component 100 according to an exemplary embodiment of the present disclosure will be described.

[0042] A multilayer electronic component 100 according to an exemplary embodiment of the present disclosure includes: a main body 110 in which internal electrodes 121 and 122 and dielectric layers 111 are alternately disposed, the internal electrodes 121 and 122 including Ni and Sn; and external electrodes 131 and 132 disposed on a surface of the main body 110, connected to the internal electrodes, and including Cu and Sn, wherein the internal electrodes 121 and 122 include a Ni-Cu-Sn alloy in regions of the internal electrodes 121 and 122 that are in contact with the external electrodes 131 and 132, and an amount of Sn included in the internal electrodes satisfies the following formula: 1<C2 / C1<13.5, wherein C1 is an at% of Sn included in the internal electrodes 121 and 122 at a central portion of the main body, C2 is an at% of Sn included in the internal electrodes 121 and 122 at a point 2μm away from a point where the internal electrodes and the external electrodes are in contact with each other in an inward direction of the main body, and the Sn content is based on the total amount of components included in the internal electrodes.

[0043] In the main body 110, the dielectric layers 111 and the internal electrodes 121 and 122 are alternately stacked.

[0044] The specific shape of the main body 110 is not particularly limited, but as illustrated, the main body 110 may have a hexahedral shape or a shape similar to a hexahedral shape. Due to shrinkage (or tightening) of ceramic powder particles included in the main body 110 during a firing process, the main body 110 may have a substantially hexahedral shape without having a hexahedral shape with perfectly straight lines.

[0045] The main body 110 may have: a first surface 1 and a second surface 2 opposing each other in a thickness direction (Z direction); a third surface 3 and a fourth surface 4 connected to the first surface 1 and the second surface 2 and opposing each other in a length direction (X direction); and a fifth surface 5 and a sixth surface 6 connected to the first surface 1 and the second surface 2, connected to the third surface 3 and the fourth surface 4, and opposing each other in a width direction (Y direction).

[0046] The plurality of dielectric layers 111 forming the main body 110 are in a sintered state and may be integrated, such that the boundaries between adjacent dielectric layers 111 are not obvious without using a scanning electron microscope (SEM).

[0047] According to an embodiment of the present disclosure, the raw material for forming the dielectric layer 111 is not limited as long as sufficient electrostatic capacitance can be obtained therewith. For example, a barium titanate-based material, a lead composite perovskite-based material, or a strontium titanate-based material may be used as the raw material for forming the dielectric layer 111. The barium titanate-based material may include BaTiO₃-based ceramic powder particles, and the ceramic powder particles may include BaTiO₃ and (Ba obtained by partially dissolving calcium (Ca), zirconium (Zr), etc. in BaTiO₃ 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 and 0<y<1) or Ba(Ti 1-y Zr y )O₃(0<y<1).

[0048] For the purpose of the present disclosure, various ceramic additives, organic solvents, binders, dispersants and the like may be added to powder particles such as barium titanate (BaTiO₃) as the material for forming the dielectric layer 111.

[0049] In addition, the thickness td of the dielectric layer 111 may not be limited.

[0050] However, in general, if the dielectric layer is formed to be as thin as less than 0.6 μm, particularly if the thickness of the dielectric layer is 0.41 μm or less, moisture resistance reliability may be reduced.

[0051] As described below, when the Sn content at each position of the internal electrodes is controlled according to the exemplary embodiment, moisture resistance reliability can be effectively improved even when the dielectric layers and the internal electrodes are very thin, such that sufficient moisture resistance reliability can be ensured even when the thickness of the dielectric layer is 0.41 μm or less.

[0052] Therefore, when the thickness of the dielectric layer 111 is 0.41 μm or less, the effect of improving moisture resistance reliability according to the present disclosure may be more significant.

[0053] The thickness td of the dielectric layer 111 may refer to the average thickness of the dielectric layer 111 disposed between the first internal electrode 121 and the second internal electrode 122.

[0054] The average thickness of dielectric layer 111 can be measured by scanning an image of the length-thickness (LT) cross section of the body 110 using a scanning electron microscope (SEM).

[0055] For example, regarding a specific dielectric layer extracted from an image of a length-thickness (LT) cross-section taken from the central portion of the body 110 in the width direction using SEM, the thickness of the dielectric layer can be measured at 30 equally spaced points in the length direction, and its average value can be calculated.

[0056] The thickness of the dielectric layer at 30 equidistant points can be measured at capacitor formation part A.

[0057] The main body 110 may include: a capacitor forming portion A formed inside the main body 110, which forms a capacitor using a first inner electrode 121 and a second inner electrode 122, wherein the first inner electrode 121 and the second inner electrode 122 are arranged to face each other and a dielectric layer 111 is disposed between the first inner electrode 121 and the second inner electrode 122; and covering portions 112 and 113 formed above and below the capacitor forming portion A.

[0058] Furthermore, the capacitor forming section A is the part that contributes to the capacitance of the capacitor. This section can be formed by repeatedly stacking a plurality of first internal electrodes 121 and a plurality of second internal electrodes 122 and having a dielectric layer 111 between the first internal electrodes 121 and the second internal electrodes 122.

[0059] The upper cover portion 112 and the lower cover portion 113 can be formed by stacking a single dielectric layer or two or more dielectric layers on the upper and lower surfaces of the capacitor forming portion A in the thickness direction, respectively, and can be used to prevent damage to the inner electrode due to physical stress or chemical stress.

[0060] The upper cover 112 and the lower cover 113 do not include internal electrodes and may include the same material as the dielectric layer 111.

[0061] In other words, the upper cover 112 and the lower cover 113 may include ceramic materials, such as barium titanate (BaTiO3) based ceramic materials.

[0062] Furthermore, the thickness of the covers 112 and 113 is not limited. However, the thickness tp of the covers 112 and 113 can be 20 μm or less to more easily achieve miniaturization and high capacitance of multilayer electronic components.

[0063] Furthermore, edge portions 114 and 115 may be provided on the side surface of the capacitor forming portion A.

[0064] The edge portion includes an edge portion 114 disposed on the sixth surface 6 of the body 110 and an edge portion 115 disposed on the fifth surface 5 of the body 110. That is, the edge portions 114 and 115 can be disposed on two side surfaces of the body 110 in the width direction.

[0065] like Figure 3 As shown, the edges 114 and 115 may refer to the area between the two ends of the first inner electrode 121 and the two ends of the second inner electrode 122 and the boundary surface of the body 110 in a cross section taken along the width-thickness (WT) direction of the body 110.

[0066] Edges 114 and 115 are primarily used to prevent damage to the internal electrodes due to physical or chemical stress.

[0067] Edge portions 114 and 115 can be formed during the formation of the inner electrode, which is formed by applying conductive paste to the portion of the ceramic green sheet excluding the area where the edge portions are to be formed.

[0068] In addition, in order to suppress the step difference caused by the inner electrodes 121 and 122, the edge portions 114 and 115 can be formed by cutting the inner electrodes after stacking (lamination) so that the inner electrodes are exposed to the fifth surface 5 and the sixth surface 6 of the body, and then stacking a single dielectric layer or two or more dielectric layers on the two side surfaces of the capacitor forming portion A in the width direction.

[0069] The inner electrodes 121 and 122 may be alternately disposed with the dielectric layer 111.

[0070] The internal electrode may include a first internal electrode 121 and a second internal electrode 122. The first internal electrode 121 and the second internal electrode 122 may be alternately arranged and are arranged to face each other with the dielectric layer 111 between the first internal electrode 121 and the second internal electrode 122, and the first internal electrode 121 and the second internal electrode 122 may be exposed on the third surface 3 and the fourth surface 4 of the body 110, respectively.

[0071] Reference Figure 2A The first inner electrode 121 may be spaced apart from the fourth surface 4 and exposed to the third surface 3, and the second inner electrode 122 may be spaced apart from the third surface 3 and exposed to the fourth surface 4.

[0072] In this case, the first inner electrode 121 and the second inner electrode 122 can be electrically separated from each other by the dielectric layer 111 disposed between them.

[0073] Reference Figure 4 The main body 110 can be formed by alternately stacking ceramic green sheets on which a first internal electrode 121 is printed and ceramic green sheets on which a second internal electrode 122 is printed, and then firing the green sheets.

[0074] To achieve a multilayer electronic component with high capacitance, the internal electrodes 121 and 122 may be stacked in 400 or more layers, but this disclosure is not limited thereto.

[0075] The inner electrodes 121 and 122 of this disclosure comprise Ni and Sn. Furthermore, the inner electrodes 121 and 122 of this disclosure each comprise a Ni-Cu-Sn alloy in the region where they contact the outer electrodes 131 and 132.

[0076] Ni is the main component of the internal electrode material used in multilayer ceramic capacitors. However, when Ni is used alone as the internal electrode material, corrosion may occur in the area where the internal and external electrodes are in contact due to the plating solution introduced from the external electrode during the plating process, leading to chip degradation.

[0077] According to an exemplary embodiment, since the inner electrodes 121 and 122 comprise a Ni-Cu-Sn alloy in the regions that contact the outer electrodes 131 and 132 respectively, Ni corrosion caused by the penetration of the plating solution (which may occur during plating) at the ends of the inner electrodes can be prevented. Therefore, moisture resistance reliability can be improved.

[0078] Furthermore, the Sn included in the internal electrodes 121 and 122 can suppress the aggregation and disconnection of the internal electrodes, thereby improving the capacitance of the multilayer electronic components.

[0079] Here, the Cu in the Ni-Cu-Sn alloy included in the inner electrodes 121 and 122 may be Cu that diffuses into the inner electrodes 121 and 122 during firing and is contained in the conductive paste used to form the outer electrodes.

[0080] At temperatures between 660°C and 730°C, the diffusion coefficient of Cu is approximately 100 times that of Ni, and the diffusion from Cu to Ni is primarily due to the difference in diffusion coefficients. Therefore, during firing, Cu on the outer electrodes 131 and 132 moves towards the inner electrodes through the regions of the outer electrodes 131 and 132 that are in contact with the inner electrodes 121 and 122.

[0081] Furthermore, the inner electrodes 121 and 122 of this disclosure include Sn. During firing, the Sn included in the conductive paste used to form the outer electrode also moves toward the inner electrode through the region in contact with the inner electrode. Therefore, a Ni-Cu-Sn alloy can be disposed at the end of the inner electrode.

[0082] For example, the external electrodes 131 and 132 of this disclosure can be formed using a conductive paste comprising Cu and Sn, and the internal electrodes 121 and 122 can be formed using a conductive paste comprising Ni and Sn.

[0083] In the internal electrodes 121 and 122 of the present disclosure, the amount of Sn contained in the internal electrodes 121 and 122 satisfies the following formula: 1<C2 / C1<13.5, where C1 is the content (at%) of Sn contained in the internal electrodes at the central portion of the main body 110, and C2 is the content (at%) of Sn contained in the internal electrodes 121 and 122 at a point 2 μm away from the point where the internal electrodes and the external electrodes are in contact with each other in the inward direction of the main body, wherein the content of Sn is based on the total amount of the components contained in the internal electrodes. Therefore, the occurrence of cracks can be suppressed, and the capacitance and moisture resistance reliability can be improved.

[0084] If C2 / C1 is 1 or less, Sn and Cu contained in the external electrodes may not sufficiently diffuse into the internal electrodes, making it difficult to sufficiently form a Ni-Cu-Sn alloy at the ends of the internal electrodes, and in this case, the effect of improving moisture resistance reliability may be insufficient. Therefore, C2 / C1 is preferably greater than 1, more preferably 1.1 or more, and even more preferably 1.4 or more. However, to further improve the moisture resistance reliability, C2 / C1 may be controlled to be 3.5 or higher, and 3.5≤C2 / C1<13.5 may be satisfied. Furthermore, to further improve the moisture resistance reliability and further improve the capacitance, C2 / C1 may be controlled to be 7.0 or higher, and 7.0≤C2 / C1<13.5 may be satisfied.

[0085] If C2 / C1 is 13.5 or more, Sn and Cu contained in the external electrodes may excessively diffuse into the internal electrodes, causing the internal electrodes to expand, which may lead to the occurrence of radial cracks. Therefore, C2 / C1 is preferably less than 13.5, more preferably 12 or less, and even more preferably 8.9 or less.

[0086] The content C1 and the content C2 are not limited. In a specific example, C1 may be 0.1 at% to 1.0 at%, and C2 may be 1.0 at% to 20 at%.

[0087] If C1 is greater than 1.0 at%, the internal electrodes may aggregate due to Sn, resulting in reduced connectivity, and the grain growth of dielectric grains may be suppressed due to the diffusion of Sn toward the dielectric.

[0088] If C2 is less than 1.0 at%, the effect of improving moisture resistance reliability based on the Ni-Cu-Sn alloy may be insufficient, and if C2 exceeds 20.0 at%, radial cracks may occur.

[0089] There are no limitations on the methods for controlling C1, C2, and their ratio. For example, C1, C2, and their ratio can be controlled by adjusting the Sn content, firing temperature, firing time, etc., in the conductive paste used for the external electrode and the conductive paste used for the internal electrode. As a more specific example, multilayer electronic components that satisfy the numerical range of C2 / C1 disclosed herein can be manufactured by adjusting the Sn content in the conductive paste used for the external electrode to a range of greater than or equal to 3 wt% and less than or equal to 15 wt%.

[0090] Figure 2B This is an explanation Figure 2A A diagram showing the measurement location of at% of the metal included in the inner electrode within the main body. The point 2 μm from the point where the inner and outer electrodes contact each other (the point for measuring C2) can correspond to the following regions: a region with a length of 2 μm in the inward direction from the surface where the first inner electrode 121 and the first outer electrode 131 contact each other (the third surface of the main body), and a region with a length of 2 μm in the inward direction from the surface where the second inner electrode 122 and the second outer electrode 132 contact each other (the fourth surface of the main body). Furthermore, the central portion of the main body 110 (the portion for measuring C1) can correspond to a region with a length of 2 μm in the length direction (X direction) of the main body, centered on the central axis of the main body in the length direction.

[0091] C1 and C2 can be obtained by dividing the capacitor forming section A into four regions A1, A2, A3 and A4 in the Z direction, obtaining the average value of the values ​​measured from the four internal electrodes of each region, and averaging the average value of each region.

[0092] Here, when C1 and C2 are measured at each inner electrode, C2 can be the value measured at the center point of the inner electrode in the thickness direction in the region used to measure C2, and C1 can be the value measured over the entire region of the inner electrode corresponding to the central 2μm region in the region used to measure C1.

[0093] The Cu atoms contained in the Ni-Cu-Sn alloy of the inner electrodes 121 and 122 may originate from Cu atoms included in the conductive paste for the outer electrodes that diffuse into the inner electrodes 121 and 122 during firing, and a portion of the Sn in the Ni-Cu-Sn alloy may be Sn included in the conductive paste for the outer electrodes that diffuses into the inner electrodes 121 and 122 during firing.

[0094] Therefore, the at% of Sn and Cu in the Ni-Cu-Sn alloy included in the inner electrodes 121 and 122 gradually decreases in the inward direction of the main body from the point where the inner electrode and the outer electrode come into contact with each other. Conversely, the at% of Ni in the Ni-Cu-Sn alloy included in the inner electrodes 121 and 122 gradually increases in the inward direction of the main body from the point where the inner electrode and the outer electrode come into contact with each other.

[0095] In other words, the concentrations (at%) of Cu and Sn can gradually decrease in the inward direction of the substrate, while the concentration (at%) of Ni can gradually increase in the inward direction of the substrate.

[0096] When the inner electrode contains Sn, the concentration of Sn gradually decreases from the point where the inner and outer electrodes contact each other towards the center of the body, and then can maintain a specific concentration at a specific point. This is because the Sn contained in the inner electrode can include not only the Sn included and diffused in the conductive paste used for the outer electrode, but also the Sn present in the conductive paste used to form the inner electrode.

[0097] As a specific example, the Sn concentration (at%) of the inner electrodes 121 and 122 can be gradually reduced from the point where the inner and outer electrodes are in contact with each other to a point 5 μm to 15 μm away from that point in the inward direction of the body, and then maintained at a constant concentration (at%).

[0098] In this case, the length of the region in the inner electrodes 121 and 122 with a Sn content of 5 at% or more in the inward direction of the body from the point where the inner and outer electrodes come into contact with each other can be greater than or equal to 5 μm and less than or equal to 10 μm.

[0099] If the length of the region with a Sn content of 5 at% or more in the inward direction of the body, starting from the point where the inner and outer electrodes come into contact with each other, is less than 5 μm, the effect of improving moisture resistance may be insufficient, and if the length of this region exceeds 10 μm, radial cracks may occur.

[0100] When Cu is included in the inner electrodes 121 and 122, the concentration of Cu (at%) gradually decreases inward from the point where the inner electrodes 121 and 122 contact the outer electrodes 131 and 132, thus converging to zero (0). The Cu included in the inner electrodes 121 and 122 originates from Cu included in and diffused from the conductive paste used to form the outer electrodes, and the conductive paste used to form the inner electrodes may not contain Cu.

[0101] As some embodiments, the Cu concentration (at%) of the inner electrodes 121 and 122 can be gradually reduced from the point where the inner and outer electrodes are in contact with each other to a point 5 μm to 15 μm away from that point in the inward direction of the body, and then reduced to zero.

[0102] In this case, the length of the region in the inner electrodes 121 and 122 where the Cu content is 10 at% or more in the inward direction of the body from the point where the inner and outer electrodes come into contact with each other can be greater than or equal to 5 μm and less than or equal to 10 μm.

[0103] If the length of the region with a Cu content of 10 at% or more in the inward direction of the body, starting from the point where the inner and outer electrodes come into contact with each other, is less than 5 μm, the effect of improving moisture resistance may be insufficient, and if the length of this region exceeds 10 μm, radial cracks may occur.

[0104] Internal electrodes 121 and 122 can be formed by printing a conductive paste containing Ni and Sn onto a ceramic green sheet.

[0105] In addition, the conductive paste used for the internal electrode may also include at least one of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof. Therefore, the internal electrode may also include at least one of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

[0106] The printing method for the conductive paste used for the internal electrode can be screen printing or gravure printing, and this disclosure is not limited thereto.

[0107] In addition, there is no need to limit the thickness te of the inner electrodes 121 and 122.

[0108] However, typically, if the inner electrodes 121 and 122 are formed to have a thickness of less than 0.6 μm, especially if the thickness of the inner electrodes 121 and 122 is 0.41 μm or less, the moisture-proof reliability may be degraded.

[0109] As described below, when the Sn content at each location of the inner electrode is controlled according to an exemplary embodiment, moisture resistance reliability can be improved by including an alloy containing Ni, Cu and Sn in the regions where the inner electrodes 121 and 122 are in contact with the outer electrodes 131 and 132, so that sufficient moisture resistance reliability can be ensured even when the thickness of the dielectric layer is 0.41 μm or less.

[0110] Therefore, when the thickness of the inner electrodes 121 and 122 is 0.41 μm or less, the effect of improving moisture resistance reliability according to this disclosure is more significant, and the miniaturization and high capacitance of the capacitor assembly can be achieved more easily.

[0111] The thickness te of the inner electrodes 121 and 122 may refer to the average thickness of the inner electrodes 121 and 122.

[0112] The average thickness of the inner electrodes 121 and 122 can be measured by scanning an image of the body 110 in the length-thickness (LT) direction using a scanning electron microscope (SEM).

[0113] For example, regarding a specific first inner electrode 121 and second inner electrode 122 extracted from an image of a length-thickness (LT) cross-section taken using SEM at the central portion of the body 110 in the width direction, the thickness of the first inner electrode 121 and the second inner electrode 122 can be measured at 30 equally spaced points in the length direction, and their average value can be calculated.

[0114] External electrodes 131 and 132 are disposed on the main body 110 and connected to internal electrodes 121 and 122.

[0115] like Figure 2A As shown, the external electrodes 131 and 132 may include: a first external electrode 131 disposed on the third surface 3 and connected to the first internal electrode 121; and a second external electrode 132 disposed on the fourth surface 4 and connected to the second internal electrode 122.

[0116] In this exemplary embodiment, a structure is described in which a multilayer electronic component 100 has two external electrodes 131 and 132, but the number or shape of the external electrodes 131 and 132 may be changed depending on the shape of the internal electrodes 121 and 122 or for other purposes.

[0117] The external electrodes 131 and 132 comprise Cu and Sn.

[0118] Cu is mainly used to ensure electrical connection with the internal electrode, while Sn can reduce the firing temperature to control the diffusion of Cu.

[0119] Additionally, the outer electrodes 131 and 132 may include an alloy containing Ni, Cu, and Sn in the regions where they contact the inner electrode.

[0120] As described above, at temperatures between 660°C and 730°C, the diffusion coefficient of Cu is approximately 100 times that of Ni, and the diffusion from Cu to Ni is primarily due to the difference in diffusion coefficients. Here, since Ni from the inner electrodes 121 and 122 can also diffuse into a portion of the outer electrodes, the outer electrodes 131 and 132 can also include an alloy comprising Ni, Cu, and Sn in the regions contacting the inner electrodes 121 and 122.

[0121] The external electrodes 131 and 132 can be formed using a conductive paste containing Cu and Sn. Furthermore, the conductive paste used for the external electrodes may include glass, and the external electrodes 131 and 132 can be sintered electrodes. That is, the external electrodes 131 and 132 can be formed by coating the body 110 with a conductive paste for the external electrodes and then sintering the conductive paste.

[0122] Furthermore, the conductive paste used for the external electrodes may additionally include at least one of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof. Therefore, external electrodes 131 and 132 may additionally include at least one of palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), and alloys thereof.

[0123] In addition, the external electrodes 131 and 132 may also have a multilayer structure.

[0124] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a disposed on the body 110 and plating layers 131b and 132b formed on the electrode layers 131a and 132a. Here, electrode layers 131a and 132a may refer to the aforementioned external electrodes.

[0125] In addition, a conductive resin layer comprising conductive metal and resin may be provided between the electrode layers 131a and 132a and the plating layers 131b and 132b.

[0126] The plating layers 131b and 132b are used to improve mounting characteristics. There are no restrictions on the type of plating layers 131b and 132b, and they can be plating layers including at least one of Ni, Sn, Pd and alloys thereof, or they can be formed using multiple layers.

[0127] As a more specific example of plating layers 131b and 132b, plating layers 131b and 132b may comprise a Ni plating layer or a Sn plating layer, and in this case, the Ni plating layer and the Sn plating layer may be sequentially formed on electrode layers 131a and 132a, or a Sn plating layer, a Ni plating layer, and a Sn plating layer may be sequentially formed on electrode layers 131a and 132a. Furthermore, plating layers 131b and 132b may comprise multiple Ni plating layers and / or multiple Sn plating layers.

[0128] There are no particular restrictions on the size of the multilayer electronic component 100.

[0129] However, in order to achieve miniaturization and high capacitance, it is necessary to increase the number of layers by reducing the thickness of the dielectric layer and the internal electrode. Therefore, in multilayer electronic components with a size of 0402 (length × width, 0.4mm × 0.2mm) or smaller, the effect of improving reliability and insulation resistance according to this embodiment will be significant.

[0130] Therefore, when the distance between the third and fourth surfaces of the main body is defined as L and the distance between the fifth and sixth surfaces is defined as W, L can be 0.4 mm or less, and W can be 0.2 mm or less. That is to say, the multilayer electronic component can have a 0402 dimension (length × width, 0.4 mm × 0.2 mm) or smaller.

[0131] Hereinafter, a multilayer electronic assembly according to another exemplary embodiment will be described in detail. However, since the same drawings as those in the exemplary embodiments described above can be applied, and the same reference numerals can be applied, reference will be made to... Figure 1 Figures 6 through 6 illustrate a multilayer electronic assembly according to another exemplary embodiment. Furthermore, to avoid redundancy, content that overlaps with the descriptions of the multilayer electronic assembly according to exemplary embodiments of this disclosure described above will be omitted.

[0132] A multilayer electronic assembly 100 according to another exemplary embodiment of the present disclosure includes: a body, an inner electrode and a dielectric layer alternately disposed in the body, the inner electrode comprising Ni and Sn; and an outer electrode disposed on the surface of the body, connected to the inner electrode, and comprising Cu and Sn, wherein the inner electrode comprises an alloy comprising Ni, Cu and Sn in the region in which it contacts the outer electrode, and the length of the region in which the inner electrode has Sn of 5 at% or more in the inward direction of the body from the point where the inner electrode and the outer electrode contact each other is 5 μm to 10 μm.

[0133] If the length of the region with a Sn content of 5 at% or more in the inward direction of the body from the point where the inner and outer electrodes come into contact with each other is less than 5 μm, the alloy will not be sufficiently formed at one end of the inner electrode, so the effect of improving moisture resistance may be insufficient. If the length of this region exceeds 10 μm, the alloy will be over-formed at one end of the inner electrode, resulting in increased thickness and radial cracks.

[0134] Here, in the inner electrodes 121 and 122, the Sn content gradually decreases from the point where it contacts the outer electrodes 131 and 132 to a point where the Sn content is 5 at%. This is because the inner electrodes 121 and 122 may include Sn diffused from the outer electrodes 131 and 132.

[0135] Furthermore, in the inner electrodes 121 and 122, the length of the region with a Cu content of 10 at% or more in the inward direction of the body from the point where the inner electrode and the outer electrode come into contact with each other can be greater than or equal to 5 μm and less than or equal to 10 μm.

[0136] If the length of the region with a Cu content of 10 at% or more in the inward direction of the body, starting from the point where the inner and outer electrodes come into contact with each other, is less than 5 μm, the effect of improving moisture resistance may be insufficient, and if the length of this region exceeds 10 μm, radial cracks may occur.

[0137] Here, in the inner electrodes 121 and 122, the Cu content gradually decreases from the point where the inner electrodes 121 and 122 contact the outer electrodes 131 and 132 to a point where the Cu content is 10 at%. This is because the inner electrodes 121 and 122 may include Cu diffused from the outer electrodes 131 and 132.

[0138] (Example 1)

[0139] Figure 5A and Figure 5B Images of Cu and Ni elements were obtained using SEM-EDX in the region where the inner and outer electrodes were in contact, when the outer electrode was formed using conductive paste without added Sn.

[0140] Figure 6A , Figure 6B and Figure 6C Images of Cu, Ni, and Sn elements were obtained using SEM-EDX in the region where the inner and outer electrodes were in contact, when the outer electrode was formed using an external electrode conductive paste with 5 wt% Sn added.

[0141] Figure 7A , Figure 7B and Figure 7C Images of Cu, Ni, and Sn elements were observed using SEM-EDX in the area where the inner and outer electrodes contacted each other when the outer electrode was formed using an external electrode conductive paste with 10 wt% Sn added.

[0142] Using a ZEISS Q-SEM and an OXFORD EDX as measurement devices, the end of the inner electrode in the cross section (LT section) taken at the center of the sample sheet in the width direction was observed in ESD mapping mode.

[0143] Compare Figure 5A and Figure 5B and Figure 6A , Figure 6B and Figure 6C It can be seen that Cu diffusion is more likely to occur when Sn is added. However, it can be seen that the difference in Cu diffusion is not significant.

[0144] In addition, Figure 7A , Figure 7B and Figure 7C As can be seen, the Sn of the outer electrode diffuses significantly toward the inner electrode, and... Figure 5A and Figure 5B as well as Figure 6A , Figure 6B and Figure 6C In comparison, Cu has a longer diffusion length.

[0145] Therefore, it can be seen that the length of the alloy containing Ni, Cu and Sn at the end of the inner electrode can be controlled by controlling the Sn content contained in the conductive paste used for the outer electrode.

[0146] (Example 2)

[0147] By controlling the Sn content in the conductive paste used for the external electrode and the firing conditions, sample pieces meeting the Sn content ratios specified in Table 1 were prepared. For tests 1 to 5, conductive paste for the external electrode with 5 wt% Sn was used; for tests 6 to 10, conductive paste for the external electrode with 10 wt% Sn was used.

[0148] Referring to the Sn content ratio in the inner electrodes 121 and 122 in Table 1, C2 / C1, where C1 is the Sn content in the central part of the main body 110, and C2 is the Sn content at a point 2 μm away from the point where the inner electrode and the outer electrode contact each other in the inward direction of the main body.

[0149] In addition, refer to Figure 2B In the case of the first inner electrode, a point 2 μm away from the point where the inner electrodes 121 and 122 contact each other with the outer electrodes 131 and 132 in the inward direction of the main body 110 may be a point spaced 2 μm from the third surface, and in the case of the second inner electrode, it may be a point spaced 2 μm from the fourth surface. Furthermore, the central portion of the main body 110 is a specific point within a central 10 μm region along the length direction (X direction) of the main body.

[0150] The C1 and C2 shown in Table 1 are obtained by dividing the capacitor forming section A into four regions A1, A2, A3 and A4 in the Z direction, obtaining the average value of the values ​​measured from the four internal electrodes of each region, and averaging the values ​​for each region.

[0151] For each of the test samples with the specified test number, the capacitance, presence or absence of radial cracks, and moisture resistance were evaluated and are shown in Table 1 below.

[0152] Radial cracks were observed using an optical microscope (Olympus BX53 Mx100) in a length-thickness cross-section taken at the central part of the body in the width direction.

[0153] The moisture resistance reliability is checked by applying a 4V voltage to each sample at a temperature of 85°C and a relative humidity of 85%, and measuring the time until the insulation resistance value drops to 1 / 10 or less of its initial value.

[0154] [Table 1]

[0155]

[0156] In the case of Tests 1 to 7 satisfying 1<C2 / C1<13.5 proposed in the present disclosure, it can be seen that no radial cracks occur, and the moisture resistance reliability is also excellent.

[0157] In addition, in the case of Tests 8 to 10 where C2 / C1 is 13.5 or greater, it can be seen that radial cracks are observed, and the moisture resistance reliability is also measured to be less than 50 hours, showing inferior properties.

[0158] Furthermore, it can be seen that among Tests 1 to 7, the sample pieces of Tests 3 to 7 in which C2 / C1 is 3.5 or greater have better moisture resistance reliability.

[0159] Furthermore, it can be seen that among Tests 1 to 7, the sample pieces of Test 6 and Test 7 in which C2 / C1 is 7.0 or greater have even better moisture resistance reliability and higher capacitance.

[0160] Figure 8 The measured values of the atomic percentages of Ni, Cu, and Sn in the internal electrode for Test 7 according to the distance La from the point where the internal electrode and the external electrode are in contact with each other in the inward direction of the main body are shown.

[0161] It can be seen that as the distance from the point where the internal electrode and the external electrode are in contact with each other in the inward direction of the main body increases, the atomic percentages of Cu and Sn in the internal electrode decrease and the atomic proportion of Ni increases.

[0162] As set forth above, according to the exemplary embodiments in the present disclosure, one of the various effects of the present disclosure is that the moisture resistance reliability is improved by including an alloy containing Ni, Cu, and Sn in the region where the internal electrode and the external electrode are in contact.

[0163] In addition, one of the various effects of the present disclosure is to suppress the occurrence of cracks.

[0164] In addition, one of the various effects of the present disclosure is to improve the capacitance.

[0165] Although the exemplary embodiments have been illustrated and described above, it will be readily understood by those skilled in the art that variations and modifications may be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. A multilayer electronic component, comprising: a main body, in which internal electrodes and dielectric layers are alternately disposed, wherein the internal electrodes comprise Ni and Sn; and an external electrode, disposed on a surface of the main body, connected to the internal electrodes, and comprising Cu and Sn, wherein a region of the internal electrode in contact with the external electrode comprises an alloy containing Ni, Cu and Sn, and the amount of Sn satisfies the following formula: 1<C2 / C1≤8.9, wherein C1 is the content of Sn contained in the internal electrode at a central portion of the main body, and C2 is the content of Sn in the internal electrode at a point 2 μm from a point where the internal electrode and the external electrode are in contact with each other in an inward direction of the main body, wherein the content of Sn is at% based on the total amount of components contained in the internal electrode, and wherein C1 is 0.1 at% to 1.0 at%, and C2 is 1.0 at% to 20.0 at%.

2. The multilayer electronic component according to claim 1, wherein C2 / C1 is 3.5 or more and 8.9 or less.

3. The multilayer electronic component according to claim 2, wherein C2 / C1 is 7.0 or more and 8.9 or less.

4. The multilayer electronic component according to claim 1, wherein C2 / C1 is more than 1.4 and 8.9 or less.

5. The multilayer electronic component according to claim 4, wherein C2 / C1 is 3.5 or more and 8.9 or less.

6. The multilayer electronic component according to claim 5, wherein C2 / C1 is 3.7 or more and 8.9 or less.

7. The multilayer electronic component according to claim 6, wherein C2 / C1 is 5.8 or more and 8.9 or less.

8. The multilayer electronic component according to claim 1, wherein the atomic percentage of each of Sn and Cu gradually decreases in the inward direction of the main body starting from the point where the internal electrode and the external electrode are in contact with each other.

9. The multilayer electronic component according to claim 1, wherein in a region where the distance from the point where the internal electrode and the external electrode are in contact with each other in the inward direction of the main body is 5 μm or more and 10 μm or less, the internal electrode contains 5 at% or more of Sn.

10. The multilayer electronic component according to claim 1, wherein in a region where the distance from the point where the internal electrode and the external electrode are in contact with each other in the inward direction of the main body is 5 μm or more and 10 μm or less, the internal electrode contains 10 at% or more of Cu.

11. The multilayer electronic component according to claim 1, wherein the internal electrode further comprises at least one of Pd, Ag, Au, Pt, W, Ti, and alloys thereof.

12. The multilayer electronic component according to claim 1, wherein a region of the external electrode in contact with the internal electrode comprises an alloy containing Ni, Cu and Sn.

13. The multilayer electronic component according to claim 1, wherein the external electrode further comprises glass.

14. The multilayer electronic assembly according to claim 1, wherein, The external electrode also includes at least one of Pd, Ag, Au, Pt, W, Ti, and their alloys.

15. The multilayer electronic assembly according to claim 1, wherein, The average thickness of the internal electrode is 0.41 μm or less.

16. The multilayer electronic assembly according to claim 1, wherein, The average thickness of the dielectric layer is 0.41 μm or less.

17. A multilayer electronic component, comprising: A body, an inner electrode, and a dielectric layer are alternately disposed in the body, wherein the inner electrode comprises Ni and Sn; as well as An outer electrode, disposed on the surface of the body, is connected to the inner electrode and comprises Cu and Sn. The inner electrode comprises: an alloy containing Ni, Cu, and Sn, located in the region in contact with the outer electrode; and 5 at% or more Sn, located in the region in the inward direction of the body at a distance greater than or equal to 5 μm and less than or equal to 10 μm from the point where the inner electrode and the outer electrode contact each other. Wherein, C1 is the Sn content included in the inner electrode at the central portion of the body, and C2 is the Sn content of the inner electrode at a point 2 μm away from the point where the inner electrode and the outer electrode contact each other in the inward direction of the body, wherein the Sn content is based on at% of the total amount of the components included in the inner electrode, C1 is 0.1 at% to 1.0 at%, and C2 is 1.0 at% to 20.0 at%.

18. The multilayer electronic assembly according to claim 17, wherein, The Sn content in the inner electrode gradually decreases from the point where the inner electrode contacts the outer electrode to the point where the Sn content is 5 at%.

19. The multilayer electronic assembly according to claim 17, wherein, In the region of the body in the inward direction, at a distance greater than or equal to 5 μm and less than or equal to 10 μm from the point where the inner electrode and the outer electrode contact each other, the inner electrode comprises 10 at% or more Cu.

20. The multilayer electronic assembly according to claim 17, wherein, The Cu content in the inner electrode gradually decreases from the point where the inner electrode contacts the outer electrode to the point where the Cu content is 10 at%.

21. The multilayer electronic assembly according to claim 17, wherein, The outer electrode in the region in contact with the inner electrode comprises an alloy containing Ni, Cu, and Sn.

22. A multilayer electronic component, comprising: The main body, internal electrodes, and dielectric layer are alternately disposed in the main body; as well as An outer electrode, disposed on the surface of the body, is connected to the inner electrode and comprises Cu and Sn. The inner electrode, in the region in contact with the outer electrode, comprises an alloy containing Ni, Cu, and Sn. The atomic percentage of each of Sn and Cu gradually decreases in the inward direction of the body from the point where the inner electrode and the outer electrode come into contact with each other. The amount of Sn satisfies the following formula: 1<C2 / C1≤8.9, where C1 is the content of Sn included in the inner electrode at the central portion of the main body, and C2 is the content of Sn in the inner electrode at a point 2 μm away from the point where the inner electrode and the outer electrode are in contact with each other in the inward direction of the main body, wherein the content of Sn is at% based on the total amount of the components included in the inner electrode. In a region where the distance from the point where the inner electrode and the outer electrode are in contact with each other in the inward direction of the main body is 5 μm or more and 10 μm or less, the Sn content is 5 at% or more.

23. The multilayer electronic assembly according to claim 22, wherein, The atomic percentage of Ni gradually increases in the inward direction.

24. The multilayer electronic assembly according to claim 22, wherein, In a region where the distance from the point where the inner electrode and the outer electrode are in contact with each other in the inward direction of the main body is 5 μm or more and 10 μm or less, the atomic percentage of Cu in the inner electrode is 10 at% or more.

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