Multilayer electronic component

Abstract

The present disclosure provides a multilayer electronic component. The multilayer electronic component includes: a body including a dielectric layer and an internal electrode, and having first and second surfaces opposite to each other in a first direction, third and fourth surfaces opposite to each other in a second direction, and fifth and sixth surfaces opposite to each other in a third direction; and an external electrode including a connecting portion disposed on the third surface or the fourth surface and a band portion extending from the connecting portion onto a portion of the first surface and a portion of the second surface. The external electrode includes: a base alloy layer including a Cu-Ag alloy and disposed in the band portion; a lower electrode layer in contact with the inner electrode at the connection portion and in contact with the base alloy layer at the tape portion; and an upper electrode layer disposed on the lower electrode layer. The lower electrode layer includes Cu, and the upper electrode layer includes Ag and glass.

Description

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0154965 filed in the Korean Intellectual Property Office on November 10, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to a multi-layer electronic assembly. Background Art

[0003] A multilayer ceramic capacitor (MLCC, a type of multilayer electronic component) is a chip capacitor mounted on a printed circuit board of any of various electronic products, such as an imaging device (such as a liquid crystal display (LCD) or a plasma display panel (PDP)), a computer, a smartphone, or a mobile phone, for charging or discharging therefrom. Because MLCCs are small, have high capacitance, and are easy to mount, MLCCs can be used as components of any of various electronic devices.

[0004] In recent years, the external electrodes are being thinned to miniaturize MLCCs. However, as the external electrodes become thinner, external moisture or plating solution may easily penetrate into the body of the multilayer ceramic capacitor. In particular, the external electrodes may generally be formed using a dipping method, and the thickness of the external electrodes formed using the dipping method may be small near the edge of the body. Therefore, external moisture or plating solution may easily penetrate into the body through the edge of the body. Summary of the invention

[0005] An aspect of the present disclosure is to provide a multilayer electronic component having improved moisture resistance reliability.

[0006] However, the present disclosure is not limited to the above description and may be more easily understood in the description of exemplary embodiments of the present disclosure.

[0007] According to one aspect of the present disclosure, a multilayer electronic component includes: a body including a dielectric layer and a first inner electrode and a second inner electrode alternately arranged and the dielectric layer is interposed between the first inner electrode and the second inner electrode, and having a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface connected to the first surface and the second surface and opposite to each other in the second direction, and a fifth surface and a sixth surface connected to the first surface, the second surface, the third surface and the fourth surface and opposite to each other in a third direction; and a first outer electrode and a second outer electrode, each of the first outer electrode and the second outer electrode including a first surface and a second surface opposite to each other in a first direction. The invention relates to a method for manufacturing a first external electrode comprising: a connecting portion and a band portion, wherein the connecting portion is arranged on the third surface or the fourth surface of the main body, and the band portion extends from the connecting portion to a portion of the first surface and a portion of the second surface, wherein the first external electrode comprises: a first base alloy layer, comprising a copper (Cu)-silver (Ag) alloy and arranged in the band portion; a first lower electrode layer, contacting the first internal electrode at the connecting portion and contacting the first base alloy layer at the band portion; and a first upper electrode layer, arranged on the first lower electrode layer, the first lower electrode layer may include copper (Cu), and the first upper electrode layer may include silver (Ag) and glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other aspects, features and advantages of the present disclosure will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which: Figure 1 is a perspective view schematically illustrating a multilayer electronic component according to an exemplary embodiment of the present disclosure; Figure 2 It is schematically shown Figure 1 An exploded perspective view of a main body of a multi-layer electronic assembly; Figure 3 It is schematically shown Figure 1 A cross-sectional view of section II' shown in FIG. Figure 4 It is schematically shown Figure 1 A cross-sectional view of section II-II' shown in FIG. Figure 5 It is schematically shown Figure 3 A cross-sectional view of section III-III' shown in FIG. Figure 6 FIG. 2 schematically shows a multilayer electronic component according to another exemplary embodiment of the present disclosure. Figure 3 the corresponding cross-sectional view; and Figure 7 FIG. 2 schematically shows a multilayer electronic component according to another exemplary embodiment of the present disclosure. Figure 6 The corresponding cross-sectional view. DETAILED DESCRIPTION

[0009] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The exemplary embodiments of the present disclosure may be modified in many different forms, and the scope of the present disclosure should not be limited to the exemplary embodiments set forth herein. In addition, exemplary embodiments of the present disclosure are provided in order to more fully explain the present disclosure to those skilled in the art. In the accompanying drawings, for the sake of clarity, the shapes and sizes of the elements may be exaggerated, and the same or similar reference numerals are used to indicate the same or similar components.

[0010] In addition, in the accompanying drawings, in order to clearly describe the present disclosure, parts that are not related to the description will be omitted, and for the sake of convenience of explanation, the size (e.g., thickness) of each component shown in the accompanying drawings is arbitrarily shown. Therefore, the present disclosure is not necessarily limited to the contents shown in the accompanying drawings. In addition, similar reference numerals will be used to designate similar components with similar functions throughout the drawings within the scope of the present disclosure. In addition, throughout the specification, unless explicitly described to the contrary, when an element "includes" another component, it should be understood that the element may also include other components without excluding other components.

[0011] In the drawings, a first direction may represent a thickness direction, a second direction may represent a length direction, and a third direction may represent a width direction.

[0012] Multilayer electronic components Figure 1 is a perspective view schematically illustrating a multilayer electronic component according to an exemplary embodiment of the present disclosure.

[0013] Figure 2 It is schematically shown Figure 1 An exploded perspective view of the main body of a multi-layer electronic component.

[0014] Figure 3 It is schematically shown Figure 1 A cross-sectional view of section II' shown in FIG.

[0015] Figure 4 It is schematically shown Figure 1 A cross-sectional view of the section II-II' shown in FIG.

[0016] Figure 5 It is schematically shown Figure 3 A cross-sectional view of the section III-III' shown in FIG.

[0017] In the following, reference is made to Figures 1 to 5A multilayer electronic component 100 according to an exemplary embodiment of the present disclosure is described. In addition, a multilayer ceramic capacitor (MLCC) is described herein as an example of the multilayer electronic component 100. However, it should be understood that the multilayer electronic component 100 of the present disclosure is not limited to the MLCC and may be applied to various multilayer electronic components such as an inductor, a piezoelectric element, a varistor, or a thermistor.

[0018] The multilayer electronic component 100 according to an exemplary embodiment of the present disclosure may include: a body 110 including a dielectric layer 111 and internal electrodes 121 and 122 ; and external electrodes 131 and 132 .

[0019] The body 110 is not particularly limited to a specific shape, and may have a Figure 1 and Figure 2 The body 110 may have a first surface 1 and a second surface 2 opposite to each other in a first direction, a third surface 3 and a fourth surface 4 connected to the first surface 1 and the second surface 2 and opposite to each other in the second direction, and a fifth surface 5 and a sixth surface 6 connected to the first surface 1, the second surface 2, the third surface 3 and the fourth surface 4 and opposite to each other in a third direction.

[0020] The body 110 may include a first edge portion C1 connecting the third surface 3 to the first surface 1, the second surface 2, the fifth surface 5, and the sixth surface 6; and a second edge portion C2 connecting the fourth surface 4 to the first surface 1, the second surface 2, the fifth surface 5, and the sixth surface 6. Each of the first edge portion C1 and the second edge portion C2 may have a rounded shape. The edge portions C1 and C2 may be formed by performing a barrel polishing process of the body 110. The first surface 1, the second surface 2, the third surface 3, the fourth surface 4, the fifth surface 5, and the sixth surface 6 of the body 110 may be substantially flat surfaces, and their uneven areas may be the edge portions C1 and C2.

[0021] The body 110 may include dielectric layers 111 and internal electrodes 121 and 122 alternately disposed with the dielectric layers 111 interposed between the internal electrodes 121 and 122. The plurality of dielectric layers 111 included in the body 110 may be sintered, and adjacent dielectric layers 111 may thus be integrated with each other, making it difficult to identify a boundary therebetween without using a scanning electron microscope (SEM).

[0022] The dielectric layer 111 can be formed by the following method: preparing a ceramic slurry including ceramic powder, an organic solvent, and a binder, coating the slurry on a carrier film and drying it to prepare a green ceramic sheet, and then sintering the green ceramic sheet. The ceramic powder is not particularly limited as long as the capacitor can obtain sufficient capacitance, and for example, barium titanate-based materials, lead composite perovskite-based materials, or strontium titanate-based materials can be used. The barium titanate-based ceramic powder can include, for example, barium titanate (BaTiO3) or (Ba 1-x Ca x )TiO3 (0 < x < 1), Ba(Ti 1-y Ca y )O3 (0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3 (0 < x < 1, 0 < y < 1) or Ba(Ti 1-y Zr y )O3 (0 < y < 1). Ethanol or the like can be used as the organic solvent, polyvinyl butyral or the like can be used as the binder, and the organic solvent and the binder can include known materials used in the art.

[0023] The inner electrodes 121 and 122 can include, for example, a first inner electrode 121 and a second inner electrode 122 alternately arranged in a first direction, and the dielectric layer 111 is interposed therebetween. In some embodiments, adjacent first inner electrode 121 and second inner electrode 122 can form electrode pairs with different polarities that can face each other, and the dielectric layer 111 is interposed therebetween. The first inner electrode 121 and the second inner electrode 122 can be electrically insulated from each other by the dielectric layer 111 disposed therebetween.

[0024] The first inner electrode 121 can be spaced apart from the fourth surface 4 and can be connected to the first outer electrode 131 at the third surface 3. The second inner electrode 122 can be spaced apart from the third surface 3 and can be connected to the second outer electrode 132 at the fourth surface 4.

[0025] The conductive metal included in the inner electrode 121 and / or 122 can be at least one of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and their alloys. Preferably, it can include nickel (Ni), and is not limited thereto.

[0026] The inner electrode 121 and / or 122 can be formed by the following method: coating a conductive paste for the inner electrode including a conductive metal on the green ceramic sheet with a predetermined thickness and sintering the conductive paste. The method of printing the conductive paste for the inner electrode can be a screen printing method, a gravure printing method, etc., and is not limited thereto.

[0027] The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121 and / or 122 may not be particularly limited. The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121 and / or 122 may be set based on the desired characteristics or purpose. However, in order to achieve miniaturization and high capacitance of the multilayer electronic component 100, the average thickness td of the dielectric layer 111 may be greater than or equal to 0.4 μm and less than or equal to 0.8 μm, and the average thickness te of the internal electrodes 121 and / or 122 may be greater than or equal to 0.35 μm and less than or equal to 0.65 μm. Generally, the reliability of the multilayer electronic component 100, such as its insulation resistance or breakdown voltage, may decrease as the thickness of the dielectric layer 111 or the thickness of the internal electrodes 121 and / or 122 becomes smaller. However, even when the average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121 and / or 122 satisfy the above ranges, the reliability of the multilayer electronic component 100 according to the exemplary embodiment of the present disclosure can be ensured by the external electrodes 131 and / or 132 having a multilayer structure of the multilayer electronic component 100 described below.

[0028] The average thickness td of the dielectric layer 111 may represent the average size of the dielectric layer 111 in the first direction, and the average thickness te of the internal electrodes 121 and / or 122 may represent the average size of the internal electrodes 121 and / or 122 in the first direction. The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121 and / or 122 may be measured by scanning a cross section of the body 110 in the first direction-second direction at a magnification of 10000 using a scanning electron microscope (SEM). More specifically, the average thickness td of the dielectric layer 111 may be obtained by measuring the thickness of the dielectric layer 111 at a plurality of points (e.g., at thirty equidistant points) in the second direction, and then taking their average value. In addition, the average thickness te of the internal electrodes 121 and / or 122 may be obtained by measuring the thickness of the internal electrodes 121 and / or 122 at a plurality of points (e.g., at thirty equidistant points) in the second direction, and then taking their average value. The thirty equidistant points may be specified in the capacitor forming portion Ac to be described later. In addition, when each average value is calculated by expanding the measurement target of the average thickness to ten dielectric layers 111 or ten internal electrodes 121 and / or 122, a more generalized average thickness td of the dielectric layer 111 and a more generalized average thickness te of the internal electrode 121 and / or 122 may be obtained.

[0029] The body 110 may include: a capacitor forming part Ac, which is disposed in the body 110 and forms a capacitor by including first and second internal electrodes 121 and 122 alternately disposed and having a dielectric layer 111 interposed therebetween; and a first cover part 112 and a second cover part 113, which are respectively disposed on two surfaces of the capacitor forming part Ac that are opposite to each other in the first direction. The cover parts 112 and / or 113 may be used to prevent damage to the internal electrodes 121 and / or 122 due to physical stress and / or chemical stress. The cover parts 112 and / or 113 may have a material similar to that of the dielectric layer 111, except that the cover parts 112 and / or 113 do not include the internal electrodes.

[0030] The average thickness tc of the covering portion 112 and / or 113 may not be particularly limited. In order to achieve miniaturization and high capacitance of the multilayer electronic component 100, the average thickness tc of the covering portion 112 and / or 113 may be less than or equal to 30 μm, and is not limited thereto. In an exemplary embodiment of the present disclosure, even when the average thickness tc of the covering portion 112 and / or 113 is less than or equal to 30 μm, the reliability of the multilayer electronic component 100 may be ensured by the external electrodes 131 and / or 132 having a multilayer structure described below. Here, the average thickness tc of the covering portion 112 and / or 113 may represent the average thickness of each of the first covering portion 112 and the second covering portion 113.

[0031] The average thickness tc of the covering portion 112 and / or 113 may represent the average size of the covering portion 112 and / or 113 in the first direction, and may be the average value of the size of the covering portion 112 and / or 113 in the first direction measured at five equidistant points in the second direction in a cross section of the main body 110 in the first direction-second direction passing through the center of the main body 110 in the third direction.

[0032] The body 110 may include a first edge portion 114 and a second edge portion 115 respectively provided on two surfaces of the capacitance forming portion Ac opposite to each other in the third direction. That is, the edge portions 114 and / or 115 may refer to a region between both ends of the internal electrode 121 and / or 122 in the third direction and an outer surface of the body 110 in the third direction in a cross section of the body 110 cut along the first direction-third direction.

[0033] The edge portions 114 and / or 115 may have a material similar to that of the dielectric layer 111, except that the edge portions 114 and / or 115 do not include an internal electrode. The edge portions 114 and / or 115 may serve to prevent damage to the internal electrodes 121 and / or 122 due to physical and / or chemical stress.

[0034] The edge portions 114 and / or 115 may be formed by coating a conductive paste for an internal electrode on an area of ​​the ceramic green sheet other than an area where the edge portions 114 and / or 115 are to be formed, and sintering them. Alternatively, in order to suppress a step difference caused by the internal electrodes 121 and / or 122, the edge portions 114 and / or 115 may be formed by cutting the stack after stacking the ceramic green sheets so that the internal electrodes 121 and / or 122 are exposed to two surfaces of the capacitor forming portion Ac that are opposite to each other in the third direction, and then stacking one dielectric layer or two or more dielectric layers on two surfaces of the capacitor forming portion Ac that are opposite to each other in the third direction.

[0035] The average thickness tm of the edge portion 114 and / or 115 may not be particularly limited. In order to achieve miniaturization and high capacitance of the multilayer electronic component 100, the average thickness tm of the edge portion 114 and / or 115 may be less than or equal to 30 μm, and is not limited thereto. In an exemplary embodiment of the present disclosure, even when the average thickness tm of the edge portion 114 and / or 115 is less than or equal to 30 μm, the reliability of the multilayer electronic component 100 can be ensured by the external electrodes 131 and 132 having a multilayer structure described below. Here, the average thickness tm of the edge portion 114 and / or 115 may represent the average thickness of each of the first edge portion 114 and the second edge portion 115.

[0036] The average thickness tm of the edge portion 114 and / or 115 may represent the average size of the edge portion 114 and / or 115 in the third direction, and may be the average value of the size of the edge portion 114 and / or 115 in the third direction measured at five equidistant points in the first direction in a cross-section of the main body 110 in the first direction-third direction passing through the center of the main body 110 in the second direction.

[0037] The external electrodes 131 and 132 may be disposed on the third surface 3 and the fourth surface 4 of the body 110, respectively, and extend to a portion of the first surface 1, a portion of the second surface 2, a portion of the fifth surface 5, and a portion of the sixth surface 6 of the body 110. The external electrodes 131 and 132 may include a first external electrode 131 connected to the first internal electrode 121 and a second external electrode 132 connected to the second internal electrode 122. Hereinafter, a structure of the multilayer electronic component 100 having two external electrodes 131 and 132 is described, but the structure is not limited thereto, and the number or shape of the external electrodes 131 and 132 may be changed based on the shape or form of the internal electrodes 121 and 122 or other purposes.

[0038] The external electrode 131 and / or 132 may include: a connection portion P1a and / or P2a disposed on the third surface 3 and / or the fourth surface 4; and a strip portion P1b and / or P2b extending from the corresponding connection portion P1a and / or P2a to a portion of the first surface 1 and / or a portion of the second surface 2. The strip portion P1b and / or P2b may extend from the corresponding connection portion P1a and / or P2a to a portion of the fifth surface 5 and a portion of the sixth surface 6. The external electrode 131 and / or 132 may include a corresponding corner portion P1c and / or P2c disposed between the corresponding connection portion P1a and / or P2a and the corresponding strip portion P1b and / or P2b. The corner portion P1c and / or P2c may be disposed on the corresponding edge portion C1 and / or C2 of the body 110.

[0039] The first external electrode 131 may include: a first connection portion P1a disposed on the third surface 3; a first band portion P1b extending from the first connection portion P1a to a portion of the first surface 1 and a portion of the second surface 2; and a first corner portion P1c disposed between the first connection portion P1a and the first band portion P1b.

[0040] The second external electrode 132 may include: a second connection portion P2a, which is arranged on the fourth surface 4; a second band portion P2b, which extends from the second connection portion P2a to a portion of the first surface 1 and a portion of the second surface 2; and a second corner portion P2c, which is arranged between the second connection portion P2a and the second band portion P2b.

[0041] The external electrode 131 and / or 132 may include: a base alloy layer 131a and / or 132a, including a copper (Cu)-silver (Ag) alloy and arranged in the corresponding band portion P1b and / or P2b; a lower electrode layer 131b and / or 132b, contacting the corresponding internal electrode 121 and / or 122 at the corresponding connection portion P1a and / or P2a and contacting the base alloy layer 131a and / or 132a at the band portion P1b and / or P2b; and an upper electrode layer 131c and / or 132c, arranged on the lower electrode layer 131b and / or 132b.

[0042] The first external electrode 131 may include: a first base alloy layer 131a, which is arranged in the first band portion P1b and includes a Cu-Ag alloy; a first lower electrode layer 131b, which is in contact with the first internal electrode 121 at the first connection portion P1a and in contact with the first base alloy layer 131a at the first band portion P1b; and a first upper electrode layer 131c, which is arranged on the first lower electrode layer 131b.

[0043] The second external electrode 132 may include: a second base alloy layer 132a, which is arranged in the second band portion P2b and includes a Cu-Ag alloy; a second lower electrode layer 132b, which is in contact with the second internal electrode 122 at the second connection portion P2a and in contact with the second base alloy layer 132a at the second band portion P2b; and a second upper electrode layer 132c, which is arranged on the second lower electrode layer 132b.

[0044] The base alloy layer 131a and / or 132a may be disposed in the corresponding band portion P1b and / or P2b and may prevent external moisture from penetrating into the body 110. In an exemplary embodiment, the average size of the pores included in the base alloy layer 131a and / or 132a may be smaller than the average size of the pores included in the corresponding lower electrode layer 131b and / or 132b. The pores may be a potential path through which external moisture penetrates into the body 110. The base alloy layer 131a and / or 132a may have a higher density than that of the lower electrode layer 131b and / or 132b by including a Cu-Ag alloy, thereby preventing external moisture from penetrating into the body 110.

[0045] The base alloy layer 131a and / or 132a may have an end portion disposed in the corner portion P1c and / or P2c to prevent external moisture from penetrating into the body 110 through the edge portion C1 and / or C2 of the body 110. For example, the first base alloy layer 131a may have an end portion disposed in the first corner portion P1c, and the second base alloy layer 132a may have an end portion disposed in the second corner portion P2c. Further for this example, the first base alloy layer 131a may cover the first edge portion C1, and the second base alloy layer 132a may cover the second edge portion C2.

[0046] The Cu-Ag alloy included in the base alloy layer 131a and / or 132a may include oxygen (O). In some examples, when the base alloy layer 131a and / or 132a is analyzed by using an energy dispersive X-ray spectrometer (EDS), copper (Cu), silver (Ag), and oxygen (O) may be detected in the base alloy layer 131a and / or 132a.

[0047] The lower electrode layer 131b and / or 132b may include copper (Cu). In some embodiments, the lower electrode layer 131b and / or 132b may further include glass. The glass included in the lower electrode layer 131b and / or 132b may include an oxide of one or more of barium (Ba), calcium (Ca), zinc (Zn), aluminum (Al), boron (B), and silicon (Si), and is not limited thereto.

[0048] The lower electrode layer 131b and / or 132b may include copper (Cu) as its main component. For example, when a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction is analyzed by using a scanning electron microscope (SEM) and an energy dispersive X-ray spectrometer (EDS), a ratio of an area occupied by copper (Cu) to a total area of ​​the lower electrode layer 131b and / or 132b may be greater than or equal to 80%. For example, in a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction, a ratio of an area occupied by copper (Cu) to a total area of ​​the lower electrode layer 131b and / or 132b may be greater than a ratio of an area occupied by an element other than copper (Cu) to a total area of ​​the corresponding lower electrode layer 131b and / or 132b. The total area of ​​the lower electrode layer 131b and / or 132b may represent the total area occupied by the lower electrode layer 131b and / or 132b in the image analyzed by SEM-EDS. The image may be an image showing the entire lower electrode layer 131b and / or 132b, or may be an enlarged image of a portion of the lower electrode layer 131b and / or 132b. When the lower electrode layer 131b and / or 132b is analyzed by using an energy dispersive X-ray spectrometer (EDS), copper (Cu) may be detected in the lower electrode layer 131b and / or 132b, and silver (Ag) may not be detected in the lower electrode layer 131b and / or 132b. In addition, the concentration of copper (Cu) in the lower electrode layer 131b and / or 132b may be greater than each of the concentration of copper (Cu) in the upper electrode layer 131c and / or 132c and the concentration of copper (Cu) in the base alloy layer 131a and / or 132a.

[0049] The lower electrode layer 131b and / or 132b may electrically connect the inner electrode 121 and / or 122 to the corresponding outer electrode 131 and / or 132. The inner electrode 121 and / or 122 may include nickel (Ni). In some embodiments, copper (Cu) in the lower electrode layer 131b and / or 132b may diffuse into the corresponding inner electrode 121 and / or 122 during its firing process to form a Ni-Cu alloy, thereby improving the connectivity between the inner electrode 121 and / or 122 and the outer electrode 131 and / or 132. In an exemplary embodiment, the base alloy layer 131a and / or 132a may not be disposed in the connection portion P1a and / or P2a. The first base alloy layer 131a may not be disposed in the first connection portion P1a, and the second base alloy layer 132a may not be disposed in the second connection portion P2a. In some embodiments, the first base alloy layer 131a and / or the second base alloy layer 132a may not directly contact the inner electrode 121 and / or 122. In an example, in the case where the base alloy layer 131a and / or 132a is disposed in the connection portion P1a and / or P2a, the base alloy layer 131a and / or 132a may prevent copper (Cu) of the corresponding lower electrode layer 131b and / or 132b from diffusing toward the internal electrode 121 and / or 122. This may prevent the formation of a Ni-Cu alloy. Therefore, the base alloy layer 131a and / or 132a may not be disposed in the connection portion P1a and / or P2a.

[0050] The thickness of the lower electrode layer 131b and / or 132b may not be particularly limited. For example, in a cross section of the multilayer electronic component 100 in the first direction-second direction passing through the center of the multilayer electronic component 100 in the third direction, the thickness of the lower electrode layer 131b and / or 132b in the second direction in the central region in the first direction may be less than or equal to 20 μm, and is not limited thereto.

[0051] The method of forming the base alloy layer 131a and / or 132a and the lower electrode layer 131b and / or 132b may not be particularly limited. For example, a silver (Ag) seed layer may be formed by dipping the main body 110 into a silver (Ag) paste including silver (Ag) powder, glass, an adhesive, an organic solvent, etc., removing the Ag paste applied to the third surface 3 and the fourth surface 4 of the main body 110, and then sintering the Ag paste applied to a portion of the first surface 1, a portion of the second surface 2, a portion of the fifth surface 5, and a portion of the sixth surface 6 of the main body 110. Next, the lower electrode layer 131b and / or 132b may be formed by dipping the main body 110 on which the Ag seed layer is formed into a copper (Cu) paste including copper (Cu) powder, glass, an adhesive, an organic solvent, etc., and then sintering the Cu paste. In addition, when the lower electrode layer 131b and / or 132b is formed by sintering the Cu paste, copper (Cu) in the corresponding lower electrode layer 131b and / or 132b may diffuse into the Ag seed layer and react with silver (Ag) in the Ag seed layer. As a result, the Ag seed layer may form the base alloy layer 131a and / or 132a including the Cu-Ag alloy. In order to form the base alloy layer 131a and / or 132a including the Cu-Ag alloy, the Cu paste may be sintered at a temperature greater than or equal to 600°C and less than or equal to 850°C, and is not limited thereto.

[0052] The upper electrode layer 131c and / or 132c may include silver (Ag) and glass. The glass included in the upper electrode layer 131c and / or 132c may include an oxide of one or more of barium (Ba), calcium (Ca), zinc (Zn), aluminum (Al), boron (B), and silicon (Si), and is not limited thereto.

[0053] The upper electrode layer 131c and / or 132c may include silver (Ag) as its main component. For example, when a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction is analyzed by using a scanning electron microscope (SEM) and an energy dispersive X-ray spectrometer (EDS), a ratio of an area occupied by silver (Ag) to a total area of ​​the upper electrode layer 131c and / or 132c may be greater than or equal to 80%. For example, in a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction, a ratio of an area occupied by silver (Ag) to a total area of ​​the upper electrode layer 131c and / or 132c may be greater than a ratio of an area occupied by an element other than silver (Ag) to a total area of ​​the corresponding upper electrode layer 131c and / or 132c. The total area of ​​the upper electrode layers 131c and / or 132c may represent the total area occupied by the upper electrode layers 131c and / or 132c in an image analyzed by SEM-EDS. The image may be an image showing the entire upper electrode layer 131c and / or 132c, or may be an enlarged image of a portion of the upper electrode layer 131c and / or 132c. In addition, when the upper electrode layers 131c and / or 132c are analyzed by using an energy dispersive X-ray spectrometer (EDS), silver (Ag) may be detected in the upper electrode layers 131c and / or 132c, and copper (Cu) may not be detected in the upper electrode layers 131c and / or 132c. In addition, the concentration of silver (Ag) in the lower electrode layer 131b and / or 132b may be less than each of the concentration of silver (Ag) in the upper electrode layer 131c and / or 132c and the concentration of silver (Ag) in the base alloy layer 131a and / or 132a.

[0054] The method of forming the upper electrode layer 131c and / or 132c may not be particularly limited. For example, in order to realize a thin external electrode 131 and / or 132, the upper electrode layer 131c and / or 132c may be formed by printing Ag paste on the corresponding lower electrode layer 131b and / or 132b using a screen printing method, and then sintering them. Alternatively, the upper electrode layer 131c and / or 132c may be formed by attaching a conductive sheet including silver (Ag) powder, glass, an adhesive, etc. to the corresponding lower electrode layer 131b and / or 132b, and then sintering them. The sintering process for forming the upper electrode layer 131c and / or 132c may be performed at a temperature greater than or equal to 600°C and less than or equal to 850°C, and is not limited thereto.

[0055] The upper electrode layer 131c and / or 132c may be disposed in the corresponding connection portion P1a and / or P2a. The first upper electrode layer 131c may be disposed in the first connection portion P1a, and the second upper electrode layer 132c may be disposed in the second connection portion P2a. In addition, in order to realize a thin external electrode 131 and / or 132, the corresponding upper electrode layer 131c and / or 132c may be formed by using a screen printing method. The upper electrode layer 131c and / or 132c may not be disposed in the band portion P1b and / or P2b. Optionally, in an exemplary embodiment, the end of the upper electrode layer 131c and / or 132c may be disposed in the band portion P1b and / or P2b without covering the end of the corresponding lower electrode layer 131b and / or 132b.

[0056] The thickness of the corresponding upper electrode layer 131c and / or 132c may not be particularly limited. However, in a cross section of the multilayer electronic component 100 in the first direction-second direction passing through the center of the multilayer electronic component 100 in the third direction, t2>t1 may be satisfied, wherein t1 represents the thickness of the corresponding upper electrode layer 131c and / or 132c measured in the central region of the multilayer electronic component 100 in the first direction, and t2 represents the thickness of the corresponding upper electrode layer 131c and / or 132c measured based on the outermost corresponding internal electrode in the first direction among the internal electrodes 121 and / or 122. Figure 3 As shown in , when the lower electrode layer 131b and / or 132b is formed using an immersion method, the lower electrode layer 131b and / or 132b may have a maximum thickness at its central portion in the first direction. In addition, when the upper electrode layer 131c and / or 132c is formed on the lower electrode layer 131b and / or 132b by using a screen printing method, the upper electrode layer 131c and / or 132c may be thin and flat at its central portion in the first direction and may be thick at its outer portion in the first direction. Therefore, t2 may be larger than t1. t2 may not be particularly limited and may, for example, be less than or equal to 8μm.

[0057] In an exemplary embodiment, the external electrode 131 and / or 132 may include a corresponding intermediate alloy layer 131d and / or 132d, the intermediate alloy layer 131d and / or 132d including a Cu-Ag alloy and disposed at an interface between the corresponding lower electrode layer 131b and / or 132b and the corresponding upper electrode layer 131c and / or 132c. The first external electrode 131 may include a first intermediate alloy layer 131d disposed at an interface between the first lower electrode layer 131b and the first upper electrode layer 131c, and the second external electrode 132 may include a second intermediate alloy layer 132d disposed at an interface between the second lower electrode layer 132b and the second upper electrode layer 132c.

[0058] When the corresponding upper electrode layer 131c and / or 132c is formed by sintering Ag paste, the intermediate alloy layer 131d and / or 132d may be formed by mutual reaction between copper (Cu) in the corresponding lower electrode layer 131b and / or 132b and silver (Ag) in the corresponding upper electrode layer 131c and / or 132c. The intermediate alloy layer 131d and / or 132d may be continuously or discontinuously disposed at the interface between the corresponding lower electrode layer 131b and / or 132b and the corresponding upper electrode layer 131c and / or 132c.

[0059] The Cu-Ag alloy included in the intermediate alloy layer 131d and / or 132d may include oxygen (O). That is, when the intermediate alloy layer 131d and / or 132d is analyzed by using an energy dispersive X-ray spectrometer (EDS), copper (Cu), silver (Ag), and oxygen (O) may be detected in the intermediate alloy layer 131d and / or 132d.

[0060] Like the base alloy layers 131a and 132a, the intermediate alloy layers 131d and / or 132d may include a Cu-Ag alloy having a higher density than that of the Cu-Ag alloy included in the corresponding lower electrode layers 131b and / or 132b and / or the Cu-Ag alloy in the corresponding upper electrode layers 131c and / or 132c, thereby serving to suppress the penetration of external moisture into the body 110. In an exemplary embodiment, the average size of pores included in the intermediate alloy layers 131d and / or 132d may be smaller than the average size of pores included in the upper electrode layers 131c and / or 132c.

[0061] In order to realize thin outer electrodes 131 and / or 132, the upper electrode layer 131c and / or 132c may be formed by using a screen printing method. In this example, the intermediate alloy layer 131d and / or 132d may not be formed in the band portion P1b and / or P2b and / or the corner portion P1c and / or P2c, or even if the intermediate alloy layer 131d and / or 132d is formed in the band portion P1b or P2b and / or the corner portion P1c or P2c, the intermediate alloy layer 131d and / or 132d does not have a sufficient thickness. In this case, the intermediate alloy layer 131d and / or 132d may not be able to sufficiently prevent external moisture from penetrating into the edge portion C1 and / or C2 of the body 110. On the other hand, according to an exemplary embodiment of the present disclosure, the intermediate alloy layers 131d and / or 132d can primarily suppress external moisture penetration, and the base alloy layers 131a and / or 132a covering the edge portions C1 and / or C2 can secondarily suppress external moisture penetration, thereby more effectively improving the moisture-proof reliability of the multilayer electronic component 100.

[0062] In an exemplary embodiment, in a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction, the ratio of the area of ​​the intermediate alloy layer 131d and / or 132d to the total area of ​​the corresponding external electrode 131 and / or 132 may be less than or equal to 25%. In a cross section of the multilayer electronic component 100 passing through the center of the multilayer electronic component 100 in the third direction in the first direction-second direction, the ratio of the area of ​​the first intermediate alloy layer 131d to the total area of ​​the first external electrode 131 may be less than or equal to 25%, and the ratio of the area of ​​the second intermediate alloy layer 132d to the total area of ​​the second external electrode 132 may be less than or equal to 25%. The total area of ​​the external electrodes 131 and / or 132 may represent the total area of ​​the corresponding base alloy layer 131a and / or 132a, the corresponding lower electrode layer 131b and / or 132b, the corresponding upper electrode layer 131c and / or 132c, and the corresponding intermediate alloy layer 131d and / or 132d.

[0063] When the ratio of the area of ​​the intermediate alloy layer 131d and / or 132d to the total area of ​​the corresponding external electrodes 131 and / or 132 is greater than 25%, the multilayer electronic component 100 may have a lower capacitance. In addition, the ratio of the area of ​​the intermediate alloy layer 131d and / or 132d to the total area of ​​the corresponding external electrodes 131 and / or 132 may be greater than or equal to 4%. When the ratio of the area of ​​the intermediate alloy layer 131d and / or 132d to the total area of ​​the corresponding external electrodes 131 and / or 132 is less than 4%, the moisture-proof reliability of the multilayer electronic component 100 of the present disclosure may not be significantly improved.

[0064] In an exemplary embodiment, in a cross-section of the multilayer electronic component 100 in the first direction-second direction passing through the center of the multilayer electronic component 100 in the third direction, the ratio of the area of ​​the base alloy layer 131a and / or 132a to the total area of ​​the corresponding external electrode 131 and / or 132 may be greater than or equal to 1% and less than or equal to 3%.

[0065] The thickness of the intermediate alloy layer 131d and / or 132d may not need to be particularly limited. For example, in a cross section of the multilayer electronic component 100 in the first direction-second direction passing through the center of the multilayer electronic component 100 in the third direction, the thickness of the intermediate alloy layer 131d and / or 132d may be 1 μm to 2 μm.

[0066] In some embodiments, although not shown, the external electrode 131 and / or 132 may further include a plating layer disposed on the corresponding upper electrode layer 131c and / or 132c. The type of the plating layer is not particularly limited, and the plating layer may be a plating layer including nickel (Ni), tin (Sn), palladium (Pd) and / or an alloy thereof, and may include multiple layers. The plating layer may be, for example, a nickel (Ni) plating layer or a tin (Sn) plating layer, or may have a Ni plating layer and a Sn plating layer formed in sequence. In addition, the plating layer may include multiple Ni plating layers and / or multiple Sn plating layers.

[0067] Figure 6 FIG. 2 schematically shows a multilayer electronic component 200 according to another exemplary embodiment of the present disclosure. Figure 3 Corresponding cross-sectional view. In the following, reference is made to Figure 6 A multilayer electronic component 200 according to another exemplary embodiment of the present disclosure is described, and descriptions thereof overlapping with the description of the multilayer electronic component 100 according to the exemplary embodiment of the present disclosure described above are omitted.

[0068] A multilayer electronic component 200 according to another exemplary embodiment of the present disclosure may include a body 110 and first and second external electrodes 231 and 232 .

[0069] The external electrode 231 and / or 232 may include: a base alloy layer 231a and / or 232a, including a Cu-Ag alloy and arranged in the band portion P1b and / or P2b and extending to the connecting portion P1a and / or P2a; a lower electrode layer 231b and / or 232b, contacting the internal electrode 121 and / or 122 at the connecting portion P1a and / or P2a, and contacting the base alloy layer 231a and / or 232a at the band portion P1b and / or P2b; and an upper electrode layer 231c and / or 232c, arranged on the lower electrode layer 231b and / or 232b.

[0070] The first external electrode 231 may include: a first base alloy layer 231a, including a Cu-Ag alloy and arranged in the first band portion P1b and extending to the first connecting portion P1a; a first lower electrode layer 231b, contacting the first internal electrode 121 at the first connecting portion P1a and contacting the first base alloy layer 231a at the first band portion P1b; and a first upper electrode layer 231c, arranged on the first lower electrode layer 231b.

[0071] The second external electrode 232 may include: a second base alloy layer 232a, including a Cu-Ag alloy and arranged in the second band portion P2b and extending to the second connecting portion P2a; a second lower electrode layer 232b, contacting the second internal electrode 122 at the second connecting portion P2a and contacting the second base alloy layer 232a at the second band portion P2b; and a second upper electrode layer 232c, arranged on the second lower electrode layer 232b.

[0072] The first external electrode 231 may include a first intermediate alloy layer 231d including a Cu-Ag alloy and disposed at an interface between the first lower electrode layer 231b and the first upper electrode layer 231c. The second external electrode 232 may include a second intermediate alloy layer 232d including a Cu-Ag alloy and disposed at an interface between the second lower electrode layer 232b and the second upper electrode layer 232c.

[0073] In a multilayer electronic component 200 according to another exemplary embodiment of the present disclosure, the base alloy layer 231a and / or 232a may have an end portion disposed in the connection portion P1a and / or P2a. The first base alloy layer 231a may have an end portion disposed in the first connection portion P1a, and the second base alloy layer 232a may have an end portion disposed in the second connection portion P2a. Therefore, the base alloy layer 231a and / or 232a may more effectively cover the edge portion C1 and / or C2 of the body 110, thereby further improving the moisture-proof reliability of the multilayer electronic component 200.

[0074] In an exemplary embodiment, the base alloy layer 231a and / or 232a may not contact the corresponding internal electrode 121 and / or 122. The first base alloy layer 231a may not contact the first internal electrode 121. For example, the first base alloy layer 231a may have an end portion disposed on the surface of the cover portion 112 or 113 in the second direction. The second base alloy layer 232a may not contact the second internal electrode 122. For example, the second base alloy layer 232a may have an end portion disposed on the surface of the cover portion 112 or 113 in the second direction.

[0075] The base alloy layers 231a and / or 232a may not contact the inner electrodes 121 and / or 122, so that copper (Cu) in the corresponding lower electrode layers 231b and / or 232b can be easily diffused into the inner electrodes 121 and / or 122. In this way, the moisture-proof reliability of the multilayer electronic component 200 can be improved without reducing the contact reliability between the inner electrodes 121 and / or 122 and the outer electrodes 231 and / or 232.

[0076] The method of forming the base alloy layer 231a and / or 232a may not need to be particularly limited. For example, a silver (Ag) seed layer may be formed by dipping the body 110 into a silver (Ag) paste, removing the Ag paste applied to both sides of the capacitor forming portion Ac in the second direction, and then sintering the Ag paste. Next, the Cu paste may be sintered to form the lower electrode layer 231b and / or 232b, thereby forming the base alloy layer 231a and / or 232a disposed in the band portion P1b and / or P2b and extending to the connection portion P1a and / or P2a.

[0077] Figure 7 is a schematic diagram showing a multilayer electronic component 200' according to another exemplary embodiment of the present disclosure. Figure 6 The corresponding cross-sectional view.

[0078] Reference Figure 7 , the base alloy layer 231a' and / or 232a' may be in contact with the corresponding outermost inner electrodes 121 and / or 122 in the first direction. For example, the first base alloy layer 231a' of the first outer electrode 231' may be in contact with the outermost (e.g., uppermost) first inner electrode 121 in the first direction. The second base alloy layer 232a' of the second outer electrode 232' may be in contact with the outermost (e.g., lowermost) second inner electrode 122 in the first direction. In addition, although not shown, the first base alloy layer 231a' may be in contact with the uppermost first inner electrode 121 and the lowermost first inner electrode 121 in the first direction, respectively, and the second base alloy layer 232a' may be in contact with the uppermost second inner electrode 122 and the lowermost second inner electrode 122 in the first direction, respectively.

[0079] Although the above embodiments show that both the first external electrode and the second external electrode may have a base alloy layer including a Cu-Ag alloy and disposed in the band portion, a lower electrode layer including Cu in contact with the inner electrode at the connection portion and in contact with the base alloy layer at the band portion, and an upper electrode layer including Ag and glass disposed on the lower electrode layer, it can be understood by those skilled in the art that even if only one of the first external electrode and the second external electrode has the above structure, external moisture can be prevented from penetrating into the body to a certain extent compared to the prior art, thereby improving the moisture-proof reliability of the multilayer electronic component. Therefore, the scope of the present disclosure may include a multilayer electronic component in which at least one external electrode has the above structure.

[0080] As described above, according to exemplary embodiments of the present disclosure, a multilayer electronic component may have improved moisture-proof reliability.

[0081] While exemplary embodiments have been shown and described above, it will be readily apparent to those skilled in the art that modifications and variations 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 body, comprising a dielectric layer and a first inner electrode and a second inner electrode alternately arranged with the dielectric layer interposed between the first inner electrode and the second inner electrode, and having a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface connected to the first surface and the second surface and opposite to each other in the second direction, and a fifth surface and a sixth surface connected to the first surface, the second surface, the third surface and the fourth surface and opposite to each other in a third direction; as well as a first external electrode and a second external electrode, each of the first external electrode and the second external electrode comprising a connecting portion and a band portion, the connecting portion being disposed on the third surface or the fourth surface of the body, the band portion extending from the connecting portion to a portion of the first surface and a portion of the second surface, The first outer electrode comprises: a first base alloy layer, comprising a Cu-Ag alloy and disposed in the band portion; a first lower electrode layer, contacting the first inner electrode at the connecting portion and contacting the first base alloy layer at the band portion; and a first upper electrode layer, disposed on the first lower electrode layer. The first lower electrode layer comprises Cu, and The first upper electrode layer includes Ag and glass.

2. The multilayer electronic component according to claim 1, wherein An average size of pores included in the first base alloy layer is smaller than an average size of pores included in the first lower electrode layer.

3. The multilayer electronic component according to claim 1, wherein: The first external electrode includes a first intermediate alloy layer including the Cu—Ag alloy and disposed at an interface between the first lower electrode layer and the first upper electrode layer.

4. The multilayer electronic component according to claim 3, wherein: An average size of pores included in the first intermediate alloy layer is smaller than an average size of pores included in the first upper electrode layer.

5. The multilayer electronic component according to claim 3, wherein: In a cross section of the multilayer electronic component passing through a center of the multilayer electronic component in the third direction in the first direction-the second direction, a ratio of an area of ​​the first intermediate alloy layer to a total area of ​​the first external electrode is less than or equal to 25%.

6. The multilayer electronic component according to claim 5, wherein: In the cross section, a ratio of an area of ​​the first intermediate alloy layer to a total area of ​​the first external electrode is greater than or equal to 4%.

7. The multilayer electronic component according to claim 1, wherein: The first upper electrode layer is disposed in the connecting portion.

8. The multilayer electronic component according to claim 7, wherein: An end portion of the first upper electrode layer is disposed in the strip portion without covering an end portion of the first lower electrode layer.

9. The multilayer electronic component according to claim 1, wherein: In a cross section of the multilayer electronic component in the first direction-the second direction passing through the center of the multilayer electronic component in the third direction, t2>t1 is satisfied, wherein t1 represents the thickness of the first upper electrode layer measured in the central area of ​​the multilayer electronic component in the first direction, and t2 represents the thickness of the first upper electrode layer measured based on the outermost first internal electrode in the first direction among the first internal electrodes.

10. The multilayer electronic component according to claim 1, wherein The first outer electrode further includes a corner portion disposed between the connecting portion and the band portion, and The first base alloy layer has an end portion disposed in the corner portion.

11. The multilayer electronic component according to claim 10, wherein: The first base alloy layer is not provided in the connecting portion.

12. The multilayer electronic component according to claim 1, wherein The first base alloy layer has an end portion disposed in the connecting portion.

13. The multilayer electronic component according to claim 12, wherein: The first base alloy layer does not contact the first internal electrode.

14. The multilayer electronic component according to claim 12, wherein: The first base alloy layer contacts an outermost first internal electrode in the first direction among the first internal electrodes.

15. The multilayer electronic component according to claim 1, wherein The body includes: a first edge portion connecting the third surface to the first surface, the second surface, the fifth surface, and the sixth surface; and a second edge portion connecting the fourth surface to the first surface, the second surface, the fifth surface, and the sixth surface. Each of the first edge portion and the second edge portion has a rounded shape, and The first base alloy layer covers the first edge portion or the second edge portion.

16. The multilayer electronic component according to claim 1, wherein The first lower electrode layer further comprises glass.

17. The multilayer electronic component according to claim 1, wherein: The first lower electrode layer includes Cu as its main component, and The first upper electrode layer includes Ag as its main component.

18. The multilayer electronic component according to claim 1, wherein The first external electrode further includes a plating layer disposed on the first upper electrode layer.

19. The multilayer electronic component according to claim 1, wherein: A concentration of Cu in the first lower electrode layer is greater than each of a concentration of Cu in the first upper electrode layer and a concentration of Cu in the first base alloy layer.

20. The multilayer electronic assembly of claim 1, wherein: A concentration of Ag in the first lower electrode layer is smaller than each of a concentration of Ag in the first upper electrode layer and a concentration of Ag in the first base alloy layer.

21. The multilayer electronic assembly of claim 1, wherein: The second outer electrode includes: a second base alloy layer including a Cu-Ag alloy and disposed in the strip portion; a second lower electrode layer in contact with the second inner electrode at the connection portion and in contact with the second base alloy layer at the strip portion; and a second upper electrode layer disposed on the second lower electrode layer. The second lower electrode layer includes Cu, and The second upper electrode layer includes Ag and glass.

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