Multilayer electronic component

Abstract

To improve the moisture resistance reliability of a multilayer electronic component.SOLUTION: A multilayer electronic component 100 includes a dielectric layer 111, internal electrodes 121 and 122 disposed alternately with the dielectric layer, connection parts P1a and P2a disposed on third and fourth surfaces facing each other in a second direction of a main body 110 with a hexahedron shape, and external electrodes 131 and 132 including band parts P1b and P2b extending to a part of first and second surfaces facing each other in a first direction from the connection parts. The external electrodes are formed of base alloy layers 131a and 132a disposed in the band parts and containing a Cu-Ag alloy, lower electrode layers 131b and 132b containing Cu, and upper electrode layers 131c and 132c containing Ag and glass.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a multilayer electronic component. [Background technology]

[0002] Multi-layered ceramic capacitors (MLCCs), which are one type of multi-layered electronic component, are chip-type capacitors that are mounted on printed circuit boards of various electronic products, such as visual devices such as liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, smartphones, and mobile phones, and serve to charge and discharge electricity. Multi-layered ceramic capacitors can be used as components of various electronic devices due to their advantages of being small in size, high capacity, and easy to mount.

[0003] Recently, external electrodes have been made thinner in order to miniaturize multilayer ceramic capacitors. However, the thinner the external electrodes, the easier it is for external moisture and plating solution to penetrate into the body. In particular, external electrodes are generally formed by a dipping method, but external electrodes formed by the dipping method have a thin thickness on the edge side of the body. This can cause a problem in that external moisture and plating solution can easily penetrate into the body through the edge of the body. Summary of the Invention [Problem to be solved by the invention]

[0004] One of several objects of the present invention is to improve the moisture resistance reliability of a multilayer electronic component.

[0005] However, the scope of the present invention is not limited to the above, and can be more easily understood in the course of describing specific embodiments of the present invention. [Means for solving the problem]

[0006] One embodiment of the present invention provides a laminated electronic component including: a main body including dielectric layers and internal electrodes arranged alternately with the dielectric layers, the main body including a first surface and a second surface facing a first direction, a third surface and a fourth surface connected to the first surface and the second surface and facing a second direction, and a fifth surface and a sixth surface connected to the first surface to the fourth surface and facing a third direction; and an external electrode including connection portions arranged on the third and fourth surfaces, and a band portion extending from the connection portions to a portion of the first and second surfaces, the external electrode being arranged on the band portion and including a base alloy layer including a Cu-Ag alloy, a lower electrode layer in contact with the internal electrodes at the connection portions and in contact with the base alloy layer at the band portion, and an upper electrode layer arranged on the lower electrode layer, the lower electrode layer including Cu, and the upper electrode layer including Ag and glass. Effect of the Invention

[0007] One of the various effects of the present invention is that it is possible to improve the moisture resistance reliability of a multilayer electronic component. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a schematic configuration of a multilayer electronic component according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view showing a schematic view of the main body of FIG. [Diagram 3] 2 is a cross-sectional view that shows a schematic cross section taken along line II in FIG. 1. [Figure 4] 2 is a cross-sectional view that shows a schematic cross section taken along line II-II' in FIG. 1. [Diagram 5] 3. FIG. 4 is a cross-sectional view showing a cross section taken along line III-III' in FIG. [Figure 6] FIG. 4 is a cross-sectional view showing a schematic configuration of a multilayer electronic component according to another embodiment of the present invention, which is a modification of FIG. 3. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic configuration of a multilayer electronic component according to another embodiment of the present invention, which is a modification of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

[0010] In order to clearly explain the present invention in the drawings, parts that are not relevant to the explanation are omitted, and the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to those shown in the drawings. Components having the same function within the same concept are described using the same reference numerals. Furthermore, throughout the specification, when a part is said to "include" a certain component, this does not mean that other components are excluded, but that the part may further include other components, unless otherwise specified.

[0011] In the drawings, the first direction can be defined as a thickness T direction, the second direction can be defined as a length L direction, and the third direction can be defined as a width W direction.

[0012] Multilayer Electronic Components FIG. 1 is a perspective view that shows a schematic view of a multilayer electronic component according to one embodiment of the present invention, FIG. 2 is an exploded perspective view that shows a schematic view of the main body of FIG. 1, FIG. 3 is a cross-sectional view that shows a schematic view of a cut section taken along line II of FIG. 1, FIG. 4 is a cross-sectional view that shows a schematic view of a cut section taken along line II-II' of FIG. 1, and FIG. 5 is a cross-sectional view that shows a schematic view of a cut section taken along line III-III' of FIG. 3.

[0013] Hereinafter, with reference to FIGS. 1 to 5, the multilayer electronic component 100 according to an embodiment of the present invention will be described in detail. Also, although a multilayer ceramic capacitor will be described as an example of the multilayer electronic component, the present invention is not limited thereto, and can also be applied to various multilayer electronic components, such as inductors, piezoelectric elements, varistors, or thermistors.

[0014] The multilayer electronic component 100 according to an embodiment of the present invention can include a main body 110 including dielectric layers 111 and internal electrodes 121, 122, and external electrodes 131, 132.

[0015] There is no particular limitation on the specific shape of the main body 110, but as shown in the figure, the main body 110 can have a hexahedral shape or a shape similar thereto. The main body 110 has a first surface 1 and a second surface 2 facing each other in a first direction, a third surface 3 and a fourth surface 4 facing each other in a second direction, which are connected to the first surface 1 and the second surface 2, and a fifth surface 5 and a sixth surface 6 facing each other in a third direction, which are connected to the first surface 1, the second surface 2, the third surface 3, and the fourth surface 4.

[0016] The main body 110 can include a first chamfered 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 chamfered 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. The first chamfered portion C1 and the second chamfered portion C2 can each have a round shape. The chamfered portions C1, C2 can be formed by a barrel polishing process or the like on the main 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 main body 110 can be generally flat surfaces, and regions that are not flat can be regarded as the chamfered portions C1, C2.

[0017] The main body 110 can include a dielectric layer 111 and internal electrodes 121 and 122 that are alternately arranged with the dielectric layer 111. The plurality of dielectric layers 111 forming the main body 110 are in a fired state, and the boundary between adjacent dielectric layers 111 can be integrated so as to be difficult to confirm without using a scanning electron microscope (SEM).

[0018] The dielectric layer 111 can be formed by manufacturing a ceramic slurry containing ceramic powder, an organic solvent, and a binder, applying and drying the slurry on a carrier film to provide a ceramic green sheet, and then firing the ceramic green sheet. The ceramic powder is not particularly limited as long as sufficient capacitance can be obtained. For example, a barium titanate-based material, a lead composite perovskite-based material, or a strontium titanate-based material can be used. As an example of the ceramic powder, BaTiO 3 、BaTiO 3 in which Ca (calcium), Zr (zirconium), etc. are partially solid-solved (Ba 1-x Ca x )TiO 3 (0 < x < 1), Ba(Ti 1-y Ca y )O 3 (0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O 3 (0 < x < 1, 0 < y < 1) or Ba(Ti 1-y Zr y )O 3 (0 < y < 1), etc. can be mentioned. Ethanol, etc. can be used as the organic solvent, and polyvinyl butyral, etc. can be used as the binder. The organic solvent and the binder can be known substances used in the industry.

[0019] The internal electrodes 121, 122 may include, for example, a first internal electrode 121 and a second internal electrode 122 that are alternately arranged in the first direction with the dielectric layer 111 sandwiched therebetween. That is, the first internal electrode 121 and the second internal electrode 122, which are a pair of electrodes having different polarities from each other, may be arranged to face each other with the dielectric layer 111 sandwiched therebetween. The first internal electrode 121 and the second internal electrode 122 may be electrically isolated from each other by the dielectric layer 111 disposed therebetween.

[0020] The first internal electrode 121 may be spaced apart from the fourth surface 4 and connected to the first external electrode 131 on the third surface 3 side. The second internal electrode 122 may be spaced apart from the third surface 3 and connected to the second external electrode 132 on the fourth surface 4 side.

[0021] The conductive metal contained in the internal electrodes 121, 122 may be one or more of Ni, Cu, Pd, Ag, Au, Pt, Sn, W, Ti, and alloys thereof, and more preferably may include Ni, but the present invention is not limited thereto.

[0022] The internal electrodes 121 and 122 can be formed by applying a conductive paste for internal electrodes containing a conductive metal to a predetermined thickness on the ceramic green sheet and firing the same. The method for printing the conductive paste for internal electrodes can be a screen printing method or a gravure printing method, but the present invention is not limited thereto.

[0023] The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121, 122 do not need to be particularly limited. The average thickness td of the dielectric layer 111 and the average thickness of the internal electrodes 121, 122 can be set arbitrarily according to the desired characteristics and applications. However, in order to achieve a smaller size and higher capacity of the multilayer electronic component 100, the average thickness td of the dielectric layer 111 may be 0.4 μm or more and 0.8 μm or less, and the average thickness te of the internal electrodes 121, 122 may be 0.35 μm or more and 0.65 μm or less. In general, the thinner the thickness of the dielectric layer 111 and the internal electrodes 121, 122, the more likely it is that the reliability characteristics of the multilayer electronic component 100, such as the insulation resistance and breakdown voltage, will decrease. However, since the external electrodes 131, 132 of the multilayer electronic component 100 according to one embodiment of the present invention have a multilayer structure described later, the reliability of the multilayer electronic component 100 can be ensured even if the average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121, 122 satisfy the above-mentioned ranges.

[0024] The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121, 122 refer to the average size of the dielectric layer 111 and the internal electrodes 121, 122 in the first direction, respectively. The average thickness td of the dielectric layer 111 and the average thickness te of the internal electrodes 121, 122 can be measured by scanning the cross sections of the body 110 in the first direction and the second direction with a scanning electron microscope (SEM) with a magnification of 10,000. More specifically, the average thickness td of the dielectric layer 111 can be measured by measuring the thickness at a number of points, for example, 30 points that are equally spaced in the second direction, of one dielectric layer 111, and then averaging the thicknesses. In addition, the average thickness te of the internal electrodes 121, 122 can be measured by measuring the thickness at a number of points, for example, 30 points that are equally spaced in the second direction, of one internal electrode 121, 122, and then averaging the thicknesses. The 30 equally spaced points can be specified by the capacitance forming portion Ac. On the other hand, if such average value measurements are performed for 10 dielectric layers 111 and 10 internal electrodes 121, 122, respectively, and then the average values ​​are measured, the average thickness td of the dielectric layers 111 and the average thickness te of the internal electrodes 121, 122 can be further generalized.

[0025] The body 110 may include a capacitance forming part Ac that is disposed inside the body 110 and includes first internal electrodes 121 and second internal electrodes 122 that are alternately disposed with a dielectric layer 111 therebetween to form a capacitance, and a first cover part 112 and a second cover part 113 that are disposed on both sides of the capacitance forming part Ac facing each other in a first direction. The cover parts 112 and 113 may basically serve to prevent damage to the internal electrodes due to physical or chemical stress. The cover parts 112 and 113 may have a similar configuration to the dielectric layer 111, except that they do not include internal electrodes.

[0026] The average thickness tc of the cover parts 112, 113 does not need to be particularly limited. In order to reduce the size and increase the capacity of the multilayer electronic component 100, the average thickness tc of the cover parts 112, 113 may be 30 μm or less, but the present invention is not limited to this. In one embodiment of the present invention, the external electrodes 131, 132 have a multilayer structure described below, so that the reliability of the multilayer electronic component 100 can be ensured even if the average thickness tc of the cover parts 112, 113 is 30 μm or less. Here, the average thickness tc of the cover parts 112, 113 means the average thickness of each of the first cover part 112 and the second cover part 113.

[0027] The average thickness tc of the cover parts 112, 113 may mean the average size in the first direction of the cover parts 112, 113, and may be the average value of the size in the first direction measured at five points equally spaced in the second direction in a cross section in the first and second directions passing through the center of the body 110 in the third direction.

[0028] The body 110 may include a first margin portion 114 and a second margin portion 115 disposed on both sides of the capacitance forming portion Ac facing the third direction. That is, the margin portions 114 and 115 may refer to regions between both ends of the internal electrodes 121 and 122 and the boundary surface of the body 110 in a cross section obtained by cutting the body 110 in the first and third directions.

[0029] The margin portions 114 and 115 may have a similar configuration to the dielectric layer 111, except that they do not include the internal electrodes 121 and 122. The margin portions 114 and 115 may essentially serve to prevent damage to the internal electrodes 121 and 122 due to physical or chemical stress.

[0030] The margin portions 114, 115 may be formed by applying a conductive paste for internal electrodes to the ceramic green sheets and firing the sheets, except for the portions where the margin portions are to be formed. Alternatively, in order to suppress steps due to the internal electrodes 121, 122, the margin portions 114, 115 may be formed by cutting the laminated internal electrodes 121, 122 so as to be exposed on the fifth and sixth surfaces 5, 6 of the main body, and then laminating a single dielectric layer or two or more dielectric layers on both sides of the capacitance forming portion Ac that face the third direction.

[0031] The average thickness tm of the margin portions 114, 115 does not need to be particularly limited. In order to reduce the size and increase the capacity of the multilayer electronic component 100, the average thickness tm of the margin portions 114, 115 may be 30 μm or less, but the present invention is not limited to this. In one embodiment of the present invention, the external electrodes 131, 132 have a multilayer structure described below, so that the reliability of the multilayer electronic component 100 can be ensured even if the average thickness tm of the margin portions 114, 115 is 30 μm or less. Here, the average thickness tm of the margin portions 114, 115 means the average thickness of each of the first margin portion 114 and the second margin portion 115.

[0032] The average thickness tm of the margin portions 114, 115 may mean the average size in the third direction of the margin portions 114, 115, and may be the average value of the sizes in the third direction measured at five points equally spaced in the first direction in a cross section in the first and third directions passing through the center of the body 110 in the second direction.

[0033] The external electrodes 131, 132 may be disposed on the third and fourth surfaces 3, 4 of the body 110, and may extend onto parts of the first, second, fifth and sixth surfaces 1, 2, 5, 6. The external electrodes 131, 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 in which the multilayer electronic component 100 has two external electrodes 131, 132 will be described, but the present invention is not limited thereto, and the number, shape, etc. of the external electrodes 131, 132 may be changed according to the shape of the internal electrodes 121, 122 or other purposes.

[0034] The external electrodes 131, 132 may include connection portions P1a, P2a disposed on the third and fourth surfaces 3, 4, and band portions P1b, P2b extending from the connection portions P1a, P2a to parts of the first and second surfaces 1, 2. The band portions P1b, P2b may also extend from the connection portions P1a, P2a to parts of the fifth and sixth surfaces 5, 6. The external electrodes 131, 132 may also include corner portions P1c, P2c disposed between the connection portions P1a, P2a and the band portions P1b, P2b. The corner portions P1c, P2c may be disposed on the chamfered portions C1, C2 of the main body 110.

[0035] That is, the first external electrode 131 may include a first connection portion P1a arranged on the third surface 3, a first band portion P1b extending from the first connection portion P1a to a portion of the first surface and the second surface 1, 2, and a first corner portion P1c arranged between the first connection portion P1a and the first band portion P1b.

[0036] The second external electrode 132 may include a second connection portion P2a arranged on the fourth surface 4, a second band portion P2b extending from the second connection portion P2a to a portion of the first surface and the second surfaces 1 and 2, and a second corner portion P2c arranged between the second connection portion P2a and the second band portion P2b.

[0037] The external electrodes 131, 132 are arranged in the band portions P1b, P2b and may include base alloy layers 131a, 132a containing a Cu-Ag alloy, lower electrode layers 131b, 132b that contact the internal electrodes 121, 122 at the connection portions P1a, P2a and contact the base alloy layers 131a, 132a at the band portions P1b, P2b, and upper electrode layers 131c, 132c arranged on the lower electrode layers 131b, 132b.

[0038] That is, the first external electrode 131 is arranged in the first band portion P1b and may include a first base alloy layer 131a containing a Cu-Ag alloy, a first lower electrode layer 131b that contacts the first internal electrode 121 at the first connection portion P1a and contacts the first base alloy layer 131a in the first band portion P1b, and a first upper electrode layer 131c that is arranged on the first lower electrode layer 131b.

[0039] The second external electrode 132 is arranged in the second band portion P2b and may include a second base alloy layer 132a containing a Cu-Ag alloy, a second lower electrode layer 132b that contacts the second internal electrode 122 at the second connection portion P2a and contacts the second base alloy layer 132a in the second band portion P2b, and a second upper electrode layer 132c arranged on the second lower electrode layer 132b.

[0040] The base alloy layers 131a and 132a are disposed in the band portions P1b and P2b and serve to prevent external moisture from penetrating into the main body 110. In one embodiment, the average size of the pores included in the base alloy layers 131a and 132a may be smaller than the average size of the pores included in the lower electrode layers 131b and 132b. The pores may serve as a path for external moisture to penetrate into the main body 110. That is, the base alloy layers 131a and 132a may be denser than the lower electrode layers 131b and 132b by including a Cu-Ag alloy, and thus the base alloy layers 131a and 132a may suppress external moisture from penetrating into the main body 110.

[0041] On the other hand, the chamfered portions C1 and C2 of the main body 110 may be vulnerable to the penetration of moisture from the outside. In order to prevent moisture from the outside from penetrating into the inside of the main body 110 through the chamfered portions C1 and C2 of the main body 110, it is preferable that one end of the base alloy layers 131a and 132a is disposed at the corner portions P1c and P2c. For example, one end of the first base alloy layer 131a may be disposed at the first corner portion P1c, and one end of the second base alloy layer 132a may be disposed at the second corner portion P2c. For example, the first base alloy layer 131a may cover the first chamfered portion C1, and the second base alloy layer 132a may cover the second chamfered portion C2.

[0042] The Cu-Ag alloy contained in the base alloy layers 131a and 132a may contain oxygen (O). That is, when analyzed using energy dispersive spectroscopy (EDS), Cu, Ag, and O can be detected in the base alloy layers 131a and 132a.

[0043] The lower electrode layers 131b and 132b may include Cu. The lower electrode layers 131b and 132b may include glass. The glass included in the lower electrode layers 131b and 132b may include one or more oxides of Ba, Ca, Zn, Al, B, and Si, but the present invention is not limited thereto.

[0044] The lower electrode layers 131b and 132b may contain Cu as a main component. For example, when a cross section in the first direction and a cross section in the second direction passing through the center in the third direction of the multilayer electronic component 100 are analyzed by a scanning electron microscope (SEM) and an energy dispersive spectroscopy (EDS), a ratio of an area occupied by Cu to a total area of ​​the lower electrode layers 131b and 132b may be 80% or more. For example, in the cross sections in the first direction and the second direction passing through the center in the third direction of the multilayer electronic component 100, a ratio of an area occupied by Cu to a total area of ​​the lower electrode layers 131b and 132b may be greater than a ratio of an area occupied by the remaining elements other than Cu to a total area of ​​the lower electrode layers 131b and 132b. Here, the total area of ​​the lower electrode layers 131b and 132b may mean a total area occupied by the lower electrode layers 131b and 132b in an image analyzed by SEM-EDS. The above image may be an image showing the entire lower electrode layers 131b and 132b, or may be an image showing an enlarged portion of the lower electrode layers 131b and 132b. On the other hand, when an analysis is performed using energy dispersive spectroscopy (EDS), Cu is sometimes detected in the lower electrode layers 131b and 132b, but Ag is not sometimes detected.

[0045] The lower electrode layers 131b, 132b may essentially serve to electrically connect the internal electrodes 121, 122 and the external electrodes 131, 132. In particular, when the internal electrodes 121, 122 contain Ni, Cu in the lower electrode layers 131b, 132b may diffuse to the internal electrodes 121, 122 during the sintering process to form a Ni-Cu alloy, thereby improving the connectivity between the internal electrodes 121, 122 and the external electrodes 131, 132. In one embodiment, the base alloy layers 131a, 132a may not be disposed at the connection portions P1a, P2a. That is, the first base alloy layer 131a may not be disposed at the first connection portion P1a, and the second base alloy layer 132a may not be disposed at the second connection portion P2a. If the base alloy layers 131a, 132a are arranged at the connection portions P1a, P2a, it is preferable that the base alloy layers 131a, 132a are not arranged at the connection portions P1a, P2a, since there is a possibility that Cu in the lower electrode layers 131b, 132b will diffuse to the internal electrodes 121, 122 side and hinder the formation of a Ni-Cu alloy.

[0046] The thickness of the lower electrode layers 131b and 132b does not need to be particularly limited. For example, in the cross section in the first and second directions passing through the center in the third direction of the main body 110, the thickness of the lower electrode layers 131b and 132b in the central region in the first direction may be 20 μm or less, but the present invention is not limited thereto.

[0047] The method of forming the base alloy layers 131a, 132a and the lower electrode layers 131b, 132b is not particularly limited. For example, the body 110 is dipped in an Ag paste containing Ag powder, glass, binder, organic solvent, etc., and the Ag paste applied on the third and fourth surfaces 3, 4 of the body 110 is removed, and then the Ag paste applied on the first, second, fifth and sixth surfaces 1, 2, 5, 6 of the body 110 is fired to form an Ag seed layer. Next, the body 110 on which the Ag seed layer is formed is dipped in a Cu paste containing Cu powder, glass, binder, organic solvent, etc., and then the Cu paste is fired to form the lower electrode layers 131b, 132b. On the other hand, when the lower electrode layers 131b, 132b are formed by firing the Cu paste, the Cu of the lower electrode layers 131b, 132b can diffuse to the Ag seed layer, and the Cu of the lower electrode layers 131b, 132b can react with the Ag of the Ag seed layer, so that the Ag seed layer can become the base alloy layers 131a, 132a containing a Cu-Ag alloy. To form the base alloy layers 131a, 132a containing a Cu-Ag alloy, the Cu paste may be fired at a temperature of 600°C to 850°C, but the present invention is not limited thereto.

[0048] The upper electrode layers 131c and 132c may include Ag and glass. The glass included in the upper electrode layers 131c and 132c may include an oxide of one or more of Ba, Ca, Zn, Al, B, and Si, but the present invention is not limited thereto.

[0049] The upper electrode layers 131c and 132c may include Ag as a main component. For example, when the cross sections in the first and second directions passing through the center in the third direction of the multilayer electronic component 100 are analyzed by a scanning electron microscope (SEM) and an energy dispersive spectroscopy (EDS), the ratio of the area occupied by Ag to the total area of ​​the upper electrode layers 131c and 132c may be 80% or more. For example, in the cross sections in the first and second directions passing through the center in the third direction of the multilayer electronic component 100, the ratio of the area occupied by Ag to the total area of ​​the upper electrode layers 131c and 132c may be greater than the ratio of the area occupied by the remaining elements other than Ag to the total area of ​​the upper electrode layers 131c and 132c. Here, the total area of ​​the upper electrode layers 131c and 132c may mean the total area occupied by the upper electrode layers 131c and 132c in an image analyzed by SEM-EDS. The above image may be an image showing the entire upper electrode layers 131c and 132c, or may be an image showing an enlarged portion of the upper electrode layers 131c and 132c. On the other hand, when an analysis is performed using energy dispersive spectroscopy (EDS), Ag is sometimes detected in the upper electrode layers 131c and 132c, but Cu is sometimes not detected.

[0050] The method for forming the upper electrode layers 131c and 132c does not need to be particularly limited. For example, in order to thin the external electrodes 131 and 132, the above Ag paste can be printed on the lower electrode layers 131b and 132b by a screen printing method, and then fired to form the upper electrode layers 131c and 132c. Alternatively, the upper electrode layers 131c and 132c can be formed by attaching a conductive sheet containing Ag powder, glass, a binder, and the like onto the lower electrode layers 131b and 132b, and then firing the sheet. The firing process for forming the upper electrode layers 131c and 132c may be performed at a temperature of 600° C. or higher and 850° C. or lower, but the present invention is not limited thereto.

[0051] The upper electrode layers 131c, 132c can be basically disposed at the connection portions P1a, P2a. That is, the first upper electrode layer 131c can be disposed at the first connection portion P1a, and the second upper electrode layer 132c can be disposed at the second connection portion P2a. On the other hand, when the upper electrode layers 131c, 132c are formed by a screen printing method in order to thin the external electrodes 131, 132, the upper electrode layers 131c, 132c may not be disposed at the band portions P1b, P2b. Alternatively, in one embodiment, the ends of the upper electrode layers 131c, 132c may be disposed at the band portions P1b, P2b, but may not cover the ends of the lower electrode layers 131b, 132b.

[0052] The thickness of the upper electrode layers 131c and 132c is not particularly limited. However, when the thickness of the upper electrode layer measured in the central region of the body 110 in the first direction in the cross section in the first and second directions passing through the center of the body 110 in the third direction is t1, and the thickness of the upper electrode layer measured in the internal electrode arranged at the outermost part of the internal electrodes based on the first direction is t2, t2>t1 can be satisfied. As shown in FIG. 3, when the lower electrode layers 131b and 132b are formed by the dipping method, the lower electrode layers 131b and 132b can have the maximum thickness in the central part in the first direction. Meanwhile, when the upper electrode layers 131c and 132c are formed on the lower electrode layers 131b and 132b by the screen printing method, the thickness of the upper electrode layers 131c and 132c can be thin and flat in the central part in the first direction and can be thick in the outer part in the first direction. As a result, the above t2 can be larger than t1. The above t2 does not need to be particularly limited, but may be, for example, 8 μm or less.

[0053] In one embodiment, the external electrodes 131, 132 may include intermediate alloy layers 131d, 132d including a Cu-Ag alloy disposed at the interface between the lower electrode layer 131b, 132b and the upper electrode layer 131c, 132c. That is, the first external electrode 131 may include a first intermediate alloy layer 131d disposed at the 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 the interface between the second lower electrode layer 132b and the second upper electrode layer 132c.

[0054] The intermediate alloy layers 131d and 132d can be formed by mutual reaction between Cu of the lower electrode layers 131b and 132b and Ag of the upper electrode layers 131c and 132c when the upper electrode layers 131c and 132c are formed by firing an Ag paste. The intermediate alloy layers 131d and 132d may be disposed continuously or discontinuously at the interfaces between the lower electrode layers 131b and 132b and the intermediate electrode layers 131c and 132c.

[0055] The Cu-Ag alloy contained in the intermediate alloy layers 131d and 132d may contain oxygen (O). That is, when analyzed using energy dispersive spectroscopy (EDS), Cu, Ag, and O can be detected in the intermediate alloy layers 131d and 132d.

[0056] The intermediate alloy layers 131d, 132d, like the base alloy layers 131a, 132a, contain a relatively dense Cu-Ag alloy compared to the lower electrode layers 131b, 132b and the upper electrode layers 131c, 132c, and thus can serve to prevent moisture from the outside from penetrating into the body 110. That is, in one embodiment, the average size of the pores contained in the intermediate alloy layers 131d, 132d may be smaller than the average size of the pores contained in the upper electrode layers 131c, 132c.

[0057] When the upper electrode layers 131c, 132c are formed by screen printing to thin the external electrodes 131, 132, the intermediate alloy layers 131d, 132d may not be formed on the band portions P1b, P2b and / or the corner portions P1c, P2c, or even if they are formed, the intermediate alloy layers 131d, 132d may not be formed with a sufficient thickness. If the intermediate alloy layers 131d, 132d are not formed on the band portions P1b, P2b and / or the corner portions P1c, P2c, or even if they are formed, the intermediate alloy layers 131d, 132d may not be formed with a sufficient thickness, it is not possible to sufficiently prevent moisture from penetrating the chamfered portions C1, C2 of the main body 110 from the outside. In contrast, according to one embodiment of the present invention, the intermediate alloy layers 131d, 132d primarily suppress the penetration of moisture from the outside, and secondarily, the base alloy layers 131a, 132a covering the chamfered portions C1, C2 suppress the penetration of moisture from the outside, thereby more effectively improving the moisture resistance reliability of the laminated electronic component 100.

[0058] In one embodiment, in the cross sections in the first and second directions passing through the center in the third direction of the body 110, the ratio of the area of ​​the intermediate alloy layers 131d, 132d to the total area of ​​the external electrodes 131, 132 may be 25% or less. That is, in the cross sections in the first and second directions passing through the center in the third direction of the body 110, the ratio of the area of ​​the first intermediate alloy layer 131d to the total area of ​​the first external electrode 131 may be 25% or less, 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 25% or less. Here, the total area of ​​the external electrodes 131, 132 may refer to the total area of ​​the base alloy layers 131a, 132a, the lower electrode layers 131b, 132b, the upper electrode layers 131c, 132c, and the intermediate alloy layers 131d, 132d.

[0059] If the ratio of the area of ​​the intermediate alloy layers 131d, 132d to the total area of ​​the external electrodes 131, 132 exceeds 25%, a problem of reduced capacity of the multilayer electronic component 100 may occur. On the other hand, the area of ​​the intermediate alloy layers 131d, 132d to the total area of ​​the external electrodes 131, 132 may be 4% or more. If the area of ​​the intermediate alloy layers 131d, 132d to the total area of ​​the external electrodes 131, 132 is less than 4%, the effect of the present invention in improving moisture resistance reliability may be slight.

[0060] In one embodiment, in a cross section in the first and second directions passing through the center of the body 110 in the third direction, the ratio of the area of ​​the base alloy layers 131a, 132a to the total area of ​​the external electrodes 131, 132 may be 1% to 3%.

[0061] The thickness of the intermediate alloy layers 131d and 132d does not need to be particularly limited. For example, in the cross sections in the first and second directions passing through the center of the main body 110 in the third direction, the thickness of the intermediate alloy layers 131d and 132d may be 1 μm to 2 μm.

[0062] Meanwhile, although not shown, the external electrodes 131, 132 may further include a plating layer disposed on the upper electrode layer 131c, 132c. The type of the plating layer is not particularly limited, and may be a plating layer containing Ni, Sn, Pd and / or an alloy containing these, or may be formed of a plurality of layers. The plating layer may be, for example, a Ni plating layer or a Sn plating layer, or may be in a form in which a Ni plating layer and a Sn plating layer are formed in sequence. The plating layer may also include a plurality of Ni plating layers and / or a plurality of Sn plating layers.

[0063] Fig. 6 is a cross-sectional view that illustrates a multilayer electronic component 200 according to another embodiment of the present invention, which is a modified example of Fig. 3. The multilayer electronic component 200 according to another embodiment of the present invention will be described below with reference to Fig. 6, but descriptions that overlap with those of the multilayer electronic component 100 according to the above-described embodiment of the present invention will be omitted.

[0064] A multilayer electronic component 200 according to an embodiment of the present invention may include a body 110 , a first external electrode 231 and a second external electrode 232 .

[0065] The external electrodes 231, 232 may include base alloy layers 231a, 232a arranged on the band portions P1b, P2b and extending to portions of the connection portions P1a, P2a, containing a Cu-Ag alloy, lower electrode layers 231b, 232b that contact the internal electrodes 121, 122 at the connection portions P1a, P2a and contact the base alloy layers 231a, 232a at the band portions P1b, P2b, and upper electrode layers 231c, 232c arranged on the lower electrode layers 231b, 232b.

[0066] That is, the first external electrode 231 may include a first base alloy layer 231a containing a Cu-Ag alloy, arranged in the first band portion P1b and extending into a portion of the first connection portion P1a, a first lower electrode layer 231b contacting the first internal electrode 121 at the first connection portion P1a and contacting the first base alloy layer 231a in the first band portion P1b, and a first upper electrode layer 231c arranged on the first lower electrode layer 231b.

[0067] The second external electrode 232 may include a second base alloy layer 232a arranged in the second band portion P2b and extending into a portion of the second connection portion P2a, the second base alloy layer 232a containing a Cu-Ag alloy, a second lower electrode layer 232b contacting the second internal electrode 122 at the second connection 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.

[0068] The first external electrode 231 is disposed at the interface between the first lower electrode layer 231b and the first upper electrode layer 231c and can include a first intermediate alloy layer 231d including a Cu-Ag alloy. The second external electrode 232 is disposed at the interface between the second lower electrode layer 232b and the second upper electrode layer 232c and can include a second intermediate alloy layer 232d including a Cu-Ag alloy.

[0069] In the case of the multilayer electronic component 200 according to an embodiment of the present invention, one end of the base alloy layers 231a, 232a may be disposed at the connection portions P1a, P2a. That is, one end of the first base alloy layer 231a may be disposed at the first connection portion P1a, and one end of the second base alloy layer 232a may be disposed at the second connection portion P2a. This allows the base alloy layers 231a, 232a to more effectively cover the chamfered portions C1, C2 of the main body 110, and as a result, the moisture resistance reliability of the multilayer electronic component 200 can be further improved.

[0070] In one embodiment, the base alloy layers 231a, 232a may not be in contact with the internal electrodes 121, 122. That is, the first base alloy layer 231a may not be in contact with the first internal electrode 121. For example, one end of the first base alloy layer 231a may be disposed on a side surface of the cover portions 112, 113 in the second direction. The second base alloy layer 232a may not be in contact with the second internal electrode 122. For example, one end of the second base alloy layer 232a may be disposed on a side surface of the cover portions 112, 113 in the second direction.

[0071] Since the base alloy layers 231a, 232a are not in contact with the internal electrodes 121, 122, Cu in the lower electrode layers 231b, 232b can easily diffuse toward the internal electrodes 121, 122. This makes it possible to improve the moisture resistance reliability of the multilayer electronic component 200 without deteriorating the contact between the internal electrodes 121, 122 and the external electrodes 231, 232.

[0072] The method of forming the base alloy layers 231a, 232a does not need to be particularly limited. For example, the body 110 is dipped in the Ag paste, and then the Ag paste applied on both side surfaces in the second direction of the capacitance forming portion Ac is removed, and the Ag paste is fired to form an Ag seed layer. Then, the Cu paste is fired to form the lower electrode layers 231b, 232b, and the base alloy layers 231a, 232a disposed on the band portions P1b, P2b and extending to parts of the connection portions P1a, P2a can be formed.

[0073] FIG. 7 is a cross-sectional view that illustrates a modified example of FIG. 6 and a schematic view of a multilayer electronic component 200' according to another embodiment of the present invention.

[0074] 7, the base alloy layers 231a', 232a' may contact the internal electrodes 121, 122 arranged at the outermost part based on the first direction. For example, the first base alloy layer 231a' of the first external electrode 231' may contact the first internal electrode 121 arranged at the outermost part based on the first direction. The second base alloy layer 232a' of the second external electrode 232' may contact the second internal electrode 122 arranged at the outermost part based on the first direction. Meanwhile, although not shown, the first base alloy layer 231a' may contact the first internal electrodes 121 arranged at the top and bottom, respectively, based on the first direction, and the second base alloy layer 232a' may contact the second internal electrodes 122 arranged at the top and bottom, respectively, based on the first direction.

[0075] The present invention is not limited by the above-described embodiments and the accompanying drawings, but is limited by the scope of the accompanying claims. Therefore, various substitutions, modifications and changes can be made by a person having ordinary knowledge in the art without departing from the technical idea of ​​the present invention described in the claims, and these also belong to the scope of the present invention.

[0076] In addition, the expression "one embodiment" does not mean the same embodiment, but is provided to emphasize and describe each unique feature that is different from the others. However, the above-mentioned one embodiment does not exclude being realized in combination with the features of another embodiment. For example, even if a matter described in a specific embodiment is not described in another embodiment, it can be understood as a description related to the other embodiment, unless there is a description that is opposite or contradictory to the matter in the other embodiment.

[0077] Furthermore, expressions such as "first, second" are used to distinguish one component from another, and do not limit the order and / or importance of the components. In some cases, the first component may be named the second component, and similarly the second component may be named the first component, within the scope of the rights. [Explanation of symbols]

[0078] 100, 200: Multilayer electronic components 110: Main unit 111: Dielectric layer 112, 113: Cover part 114, 115: Margin 121, 122: Internal electrode 131, 132, 231, 232: External electrode 131a, 132a, 231a, 232a: base alloy layer 131b, 132b, 231b, 232b: Lower electrode layer 131c, 132c, 231c, 232c: Upper electrode layer 131d, 132d, 231d, 232d: Intermediate alloy layer P1a, P2a: Connection parts P1b, P2b: Band section P1c, P2c: Corner section

Claims

1. a body including dielectric layers and internal electrodes alternately disposed with the dielectric layers, the body including first and second surfaces facing a first direction, third and fourth surfaces connected to the first and second surfaces and facing the second direction, and fifth and sixth surfaces connected to the first, second, third and fourth surfaces and facing the third direction; an external electrode including a connection portion disposed on the third surface and the fourth surface, and a band portion extending from the connection portion to a portion of the first surface and the second surface; The external electrode is a base alloy layer disposed on the band portion and containing a Cu-Ag alloy; a lower electrode layer contacting the internal electrode at the connection portion and contacting the base alloy layer at the band portion; and an upper electrode layer disposed on the lower electrode layer; the lower electrode layer includes Cu; The upper electrode layer comprises Ag and glass.

2. The external electrode is 2. The laminated electronic component according to claim 1, further comprising an intermediate alloy layer, the intermediate alloy layer including a Cu--Ag alloy, disposed at an interface between the lower electrode layer and the upper electrode layer.

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

4. The multilayer electronic component according to claim 2 , wherein an average size of pores contained in the intermediate alloy layer is smaller than an average size of pores contained in the upper electrode layer.

5. 3. The multilayer electronic component according to claim 2, wherein in a cross section in the first direction and the second direction passing through the center of the main body in the third direction, the ratio of the area of ​​the intermediate alloy layer to the total area of ​​the external electrodes is 25% or less.

6. The multilayer electronic component according to claim 1 , wherein the upper electrode layer is disposed on the connection portion.

7. 7. The multilayer electronic component according to claim 6, wherein an end of the upper electrode layer is disposed in the band portion and does not cover an end of the lower electrode layer.

8. In a cross section in the first direction and the second direction passing through a center in the third direction of the main body, 2. The multilayer electronic component according to claim 1, wherein t2>t1 satisfies a relationship where t1 is a thickness of the upper electrode layer measured in a central region of the body in the first direction and t2 is a thickness of the upper electrode layer measured in an internal electrode that is arranged at an outermost portion of the internal electrodes based on the first direction.

9. the external electrode includes a corner portion disposed between the connection portion and the band portion, The multilayer electronic component according to claim 1 , wherein one end of said base alloy layer is disposed at said corner portion.

10. The laminated electronic component according to claim 9 , wherein the base alloy layer is not disposed in the connection portion.

11. The multilayer electronic component according to claim 1 , wherein one end of the base alloy layer is disposed in the connection portion.

12. The laminated electronic component according to claim 11 , wherein the base alloy layer is not in contact with the internal electrodes.

13. the main body includes a first chamfered portion connecting the third surface to the first surface, the second surface, the fifth surface, and the sixth surface, and a second chamfered portion connecting the fourth surface to the first surface, the second surface, the fifth surface, and the sixth surface, the first chamfered portion and the second chamfered portion each have a rounded shape, The multilayer electronic component according to claim 1 , wherein the base alloy layer covers the first chamfered portion or the second chamfered portion.

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

15. the lower electrode layer contains Cu as a main component, The multilayer electronic component according to claim 1 , wherein the upper electrode layer contains Ag as a main component.

16. The multilayer electronic component according to claim 1 , wherein the external electrodes further include a plating layer disposed on the upper electrode layer.

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