Multilayer electronic components

Abstract

To solve the problem that floating occurs in an interface between a sintered electrode layer and a conductive resin layer by outgas generated in a conductive resin layer at the time of reflow application, the problem that an excess Sn inside the conductive resin layer is eluted to the surface of an external electrode and degrades plating property of a laminated type electronic component, and the problem that metal particles exist in a state of being dispersed in the conductive resin layer, and electric connectivity between the sintered electrode layer and the conductive resin layer deteriorates.SOLUTION: A laminated type electronic component includes a body including a dielectric layer and a plurality of internal electrodes laminated so as to sandwich the dielectric layer therebetween, and an external electrode arranged on the body, wherein the external electrode includes a first electrode layer which is connected to the internal electrode, and a second electrode layer which is arranged on the first electrode layer and contains a conductive part containing an Ag-Sn alloy and a resin, and in at least a partial cross section of the second electrode layer, an area ratio of the Ag-Sn alloy to the area of the conductive part is 3-50%.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a stacked electronic component. [Background technology]

[0002] A multilayer ceramic capacitor (MLCC), a type of multilayer electronic component, is a chip-type capacitor that is mounted on the printed circuit boards of various electronic products such as liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, smartphones, and mobile phones, and plays the role of charging or discharging electricity.

[0003] Such multilayer ceramic capacitors are important chip components used in industries such as communications, computers, home appliances, and automobiles due to their advantages of being small, yet guaranteeing high capacitance, and being easy to implement. In particular, they are core passive elements used in various electrical, electronic, and information communication devices such as mobile phones, computers, and digital TVs.

[0004] Recently, with the miniaturization and increased performance of electronic devices, there has been a trend towards smaller and higher-capacitance multilayer ceramic capacitors. This trend has increased the importance of ensuring the high reliability of multilayer ceramic capacitors.

[0005] As a way to ensure the high reliability of such multilayer ceramic capacitors, a technique has been disclosed in which a conductive resin layer is applied to the external electrodes to absorb tensile stress generated in the mechanical or thermal environment and to prevent cracks caused by stress.

[0006] Such conductive resin layers serve to electrically and mechanically bond the sintered electrode layer and the plating layer of the external electrodes of the multilayer ceramic capacitor, and protect the multilayer ceramic capacitor from mechanical and thermal stresses caused by process temperatures and warping impacts of the substrate during circuit board mounting.

[0007] However, when the conductive resin layer is applied in a high-temperature reflow environment, outgassing generated in the conductive resin layer may cause delamination at the interface between the sintered electrode layer and the conductive resin layer.

[0008] Furthermore, in the case of a conductive resin layer, since conductive metal particles exist in a dispersed form within the conductive resin layer, there was a problem in that the electrical conductivity was weak and the electrical connectivity between the sintered electrode layer and the conductive resin layer was reduced.

[0009] To solve these problems, Patent Document 1 discloses a conductive resin layer containing an intermetallic compound such as Ag3Sn in order to improve the electrical and mechanical bonding force between the sintered electrode layer and the conductive resin layer.

[0010] However, as the Ag3Sn content in the conductive resin layer increased, excess Sn inside the conductive resin layer leached out onto the surface of the external electrodes, which caused a problem in that it reduced the plating performance of the multilayer ceramic capacitor. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] KR10-2018-0084030A [Overview of the project] [Problems that the invention aims to solve]

[0012] One of the several objectives of the present invention is to solve the problem of delamination occurring at the interface between the sintered electrode layer and the conductive resin layer due to outgassing generated in the conductive resin layer during reflow application.

[0013] One of the several objectives of the present invention is to solve the problem of excess Sn inside the conductive resin layer dissolving onto the surface of the external electrode and reducing the plating performance of the multilayer electronic component.

[0014] One of several objectives of the present invention is to solve the problem of reduced electrical connectivity between the sintered electrode layer and the conductive resin layer, which occurs when metal particles are dispersed within the conductive resin layer.

[0015] However, the objectives of the present invention are not limited to those described above and can be more easily understood in the process of describing specific embodiments of the present invention. [Means for solving the problem]

[0016] One embodiment of the present invention provides a laminated electronic component comprising a body including a dielectric layer and a plurality of internal electrodes laminated with the dielectric layer in between, and an external electrode disposed on the body, wherein the external electrode includes a first electrode layer connected to the internal electrodes, and a second electrode layer disposed on the first electrode layer and including a conductive portion containing an Ag-Sn alloy and a resin, and in at least a portion of the cross-section of the second electrode layer, the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion is 3 to 50%. [Effects of the Invention]

[0017] One of the various effects of the present invention is to suppress the occurrence of floating at the interface between the sintered electrode layer and the conductive resin layer due to outgassing generated in the conductive resin layer during reflow application.

[0018] One of the various objectives of the present invention is to improve the plating performance of multilayer electronic components by preventing excess Sn inside the conductive resin layer from dissolving onto the surface of the external electrode.

[0019] One of the various objects of the present invention is to improve the weak electrical connectivity between the sintered electrode layer and the conductive resin layer.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view schematically showing a laminated electronic component according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view taken along the line I-I' of FIG. 1. [Figure 3] It is an enlarged view showing an enlarged A region of FIG. 2. [Figure 4] It is an enlarged view of the A region of FIG. 2 showing an embodiment of the present invention. [Figure 5] It is an enlarged view of the A region of FIG. 2 showing an embodiment of the present invention. [Figure 6] It is an image taken using a scanning electron microscope (SEM; Scanning Electron Microscope) of a cross-section near the A region of a laminated electronic component according to an embodiment of the present invention. [Figure 7a] It is an image in which the region where the conductive portion is formed in FIG. 6 is colored. [Figure 7b] It is an image obtained by monochrome processing of the E region of FIG. 7a. [Figure 8a] It is an image in which the region where the Ag-Sn alloy is formed in FIG. 6 is colored. [Figure 8b] It is an image obtained by monochrome processing of the E region of FIG. 8a. [Figure 9] It is an image taken of the elution of Sn on the outer surface of the second electrode layer.

Modes for Carrying Out the Invention

[0021] Embodiments of the present invention will be described below with reference to specific embodiments and accompanying drawings. However, embodiments of the present invention can be modified into several other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to give a more complete explanation of the present invention to a person of the ordinary skill. Accordingly, the shapes and sizes of elements in the drawings may be enlarged or reduced (or highlighted or simplified) for a clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

[0022] Furthermore, in order to clearly illustrate the present invention in the drawings, parts unrelated to the explanation have been omitted, and the size and thickness of each component shown in the drawings are shown arbitrarily for the convenience of explanation; therefore, the present invention is not necessarily limited by the illustrations. Also, components that have the same function within the scope of the same idea are described using the same reference numerals. Moreover, throughout the specification, when a part "includes" a certain component, unless otherwise stated to the contrary, it does not mean that other components are excluded, but rather that other components may be further included.

[0023] In drawings, the first direction can be defined as the lamination direction or thickness (T) direction, the second direction as the length (L) direction, and the third direction as the width (W) direction.

[0024] The following describes in detail a stacked electronic component according to one embodiment of the present invention with reference to Figures 1 to 3.

[0025] A stacked electronic component 100 according to one embodiment of the present invention includes a main body 110 including a dielectric layer 111 and a plurality of internal electrodes 121, 122 stacked with the dielectric layer in between, and external electrodes 130, 140 disposed on the main body, wherein the external electrodes include first electrode layers 131, 141 connected to the internal electrodes and second electrode layers 132, 142 disposed on the first electrode layers and including conductive parts 132a, 142a containing an Ag-Sn alloy and resin 132b, 142b, wherein in the cross-section of at least a portion of the second electrode layers 132, 142, the area ratio of the Ag-Sn alloy to the area of ​​the conductive parts 132a, 142a is 3 to 50%.

[0026] The main body 110 has a dielectric layer 111 and first and second internal electrodes 121 and 122 stacked alternately.

[0027] There are no particular restrictions on the specific shape of the main body 110, but as shown in the figure, the main body 110 can be hexahedral or a similar shape. Due to the shrinkage of the ceramic powder contained in the main body 110 during the firing process and the polishing of the corners, the main body 110 may not be a perfectly straight hexahedron, but may be substantially hexahedral.

[0028] The main body 110 may have 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 connected to the first surface 1 and the second surface 2 and facing each other in a second direction, and a fifth surface 5 and a sixth surface 6 connected to the first surface 1 and the second surface and connected to the third surface 3 and the fourth surface 4, and facing each other in a third direction.

[0029] The multiple dielectric layers 111 forming the main body 110 are in a fired state, and the boundaries between adjacent dielectric layers 111 can be integrated to such an extent that they are difficult to confirm without using a scanning electron microscope (SEM).

[0030] The material for forming the dielectric layer 111 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, a strontium titanate-based material, or the like can be used. The barium titanate-based material can contain BaTiO3-based ceramic powder. Examples of the ceramic powder include BaTiO3, (Ba 1-x Ca x )TiO3 in which Ca (calcium), Zr (zirconium), etc. are partially solid-dissolved in BaTiO3, Ba(Ti 1-y Ca y )O3, (Ba 1-x Ca x )(Ti 1-y Zr y )O3, or Ba(Ti 1-y Zr y )O3, etc.

[0031] At this time, the average thickness of the dielectric layer 111 can be arbitrarily changed according to the capacitance design of the multilayer electronic component 100, and can be configured to be 0.1 to 10 μm after firing in consideration of the size and capacitance of the main body 110, but the present invention is not limited thereto.

[0032] The main body 110 can include a first internal electrode 121 and a second internal electrode 122, a capacitance forming portion where capacitance is formed, and cover portions 112 and 113 formed on the upper and lower portions of the capacitance forming portion.

[0033] The upper cover portion 112 and the lower cover portion 113 can be formed by laminating a single dielectric layer or two or more dielectric layers on the upper and lower surfaces of the capacitance forming portion in the first direction or the thickness direction, and can basically play a role in preventing damage to the internal electrodes due to physical or chemical stress.

[0034] <神仙居 The upper cover portion 112 and the lower cover portion 113 may have the same material and structure as the dielectric layer 111 of the capacitance forming portion, except that they do not include internal electrodes. The upper collar portion 112 and the lower cover portion 113 may each have a thickness of 25 μm or less, but the present invention is not limited thereto.

[0035] The internal electrodes 121 and 122 can be arranged alternately with the dielectric layer 111, and the first internal electrode 121 and the second internal electrode 122 can be arranged facing each other with the dielectric layer 111 in between.

[0036] In other words, the first internal electrode 121 and the second internal electrode 122 are a pair of electrodes having different polarities. A conductive paste for internal electrodes containing a conductive metal is printed on the dielectric layer 111 to a predetermined thickness, and the electrodes are arranged so as to be alternately exposed through the third surface 3 and the fourth surface 4 of the main body 110 along the stacking direction of the dielectric layer 111, with the dielectric layer 111 in between. They are electrically insulated from each other by the dielectric layer 111 placed in between.

[0037] Therefore, the first internal electrode 121 can be electrically connected to the first external electrode 130 by contacting it on the third surface 3, and the second internal electrode 122 can be electrically connected to the second external electrode 140 by contacting it on the fourth surface 4.

[0038] The average thickness of the first internal electrode 121 and the second internal electrode 122 can be determined according to the application, for example, it can be 0.2 to 1.0 μm considering the size and volume of the main body 110, but the present invention is not limited thereto.

[0039] The conductive metals included in the first internal electrode 121 and the second internal electrode 122 may be one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof, but the present invention is not limited thereto.

[0040] The first electrode layers 131 and 141 are directly connected to the first internal electrode 121 and the second internal electrode 122, ensuring electrical conductivity between the external electrodes 130 and 140 and the first internal electrode 121 and the second internal electrode 122. Specifically, the first electrode layers 131 and 141 are arranged on the third surface 3 and the fourth surface 4 of the main body 110, and are connected to the first internal electrode 121 and the second internal electrode 122, respectively, which are alternately exposed via the third surface 3 and the fourth surface 4 of the main body 110, thereby ensuring electrical conductivity between the first external electrode 130 and the second external electrode 140 and the first internal electrode 121 and the second internal electrode 122.

[0041] In this case, the first electrode layers 131 and 141 may contain a conductive metal and glass, and may be sintered electrodes. The conductive metal may consist of, for example, one of silver (Ag), lead (Pb), platinum (Pt), nickel (Ni), and copper (Cu), or an alloy thereof, and more preferably may include copper (Cu).

[0042] The above glass may have a composition of mixed oxides, and may be one or more selected from the group consisting of silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, and alkaline earth metal oxide, but the present invention is not limited thereto.

[0043] The first electrode layers 131 and 141 can be arranged on the third surface 3 and fourth surface 4 of the main body 110, extending to the first surface 1 and second surface 2 and the fifth surface 5 and sixth surface 6 of the main body 110, respectively.

[0044] Referring to Figure 3, area A shows a magnified view of a portion of the first external electrode 130. The only difference is that the first external electrode 130 is connected to the first internal electrode 121, and the second external electrode 140 is connected to the second internal electrode 122. Since the configurations of the first external electrode 130 and the second external electrode 140 are similar, the following explanation will be based on the first external electrode 130, but this will also include the explanation regarding the second external electrode 140.

[0045] The second electrode layer 132 is disposed on the electrode layer 131 and includes a conductive portion 132a containing an Ag-Sn alloy and a resin 132b. In this case, the conductive portion 132a may have electrical conductivity, and the resin 132b may have electrical insulating properties.

[0046] The resin 132b plays a role in mechanically bonding the third electrode layers 133 and 134 formed on the first electrode layer 131 and the second electrode layer 132, imparting elasticity to the external electrode 130, absorbing tensile stress generated in the mechanical or thermal environment when mounting the multilayer electronic component 100 to the substrate, thereby preventing crack formation and protecting the multilayer electronic component 100 from substrate warping impact.

[0047] The conductive portion 132a may, for example, contain a conductive metal, and the silver (Ag)-tin (Sn) alloy contained in the conductive portion 132a may be Ag3Sn. In this case, Ag3Sn may refer to an intermetallic compound formed by the interaction of silver (Ag) contained in the conductive resin composition forming the second electrode layer 132 and a low-melting-point metal such as tin (Sn) or a tin (Sn) alloy.

[0048] The conductive portion 132a can have a network structure in which the conductive metals are interconnected, and can play a role in electrically connecting the first electrode layer 131 and the third electrode layers 133 and 134. In particular, silver (Ag) has a high reactivity with tin (Sn) among metals, so it can easily form an Ag-Sn alloy, thereby improving the interconnectivity of the conductive metals in the second electrode layer 132. As a result, the electrical connectivity can be improved compared to conventional conductive resin layers that ensure electrical connectivity by hopping conduction.

[0049] According to one embodiment of the present invention, in at least a portion of the cross-section of the second electrode layer 132, the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion 132a can be 3 to 50%. When the above conditions are met, the conductive portion 132a having an excellent network structure can be realized by improving the interconnectivity of the conductive metals in the second electrode layer 132. As a result, the capacitance of the stacked electronic component 100 can be improved, and electrical characteristics such as ESR can be reduced can be improved.

[0050] Furthermore, when the above conditions are met, the conductive portion 131a having a network structure is connected to the first electrode layer 131, thereby suppressing the occurrence of floating at the interface between the first electrode layer 131 and the second electrode layer 132. This ensures excellent mechanical and electrical connectivity between the first electrode layer 131 and the second electrode layer 132.

[0051] Conventionally, when reflow soldering was applied to the second electrode layer 132, outgassing generated in the second electrode layer 132 caused a problem of lifting at the interface between the first electrode layer 131 and the second electrode layer 132. Reflow soldering refers to the heat treatment used to melt and join solder when mounting multilayer electronic components 100 onto a substrate using solder.

[0052] On the other hand, according to the stacked electronic component 100 of one embodiment of the present invention, by adjusting the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion 132a to 3-50%, the bonding force between the first electrode layer 131 and the second electrode layer 132 can be ensured even in high-temperature environments such as reflow, thereby suppressing the occurrence of floating at the interface between the first electrode layer 131 and the second electrode layer 132.

[0053] If the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion 132a is less than 3% in at least a portion of the cross-section of the second electrode layer 132, the Ag-Sn alloy may not be sufficiently distributed in the conductive portion 132a, which may reduce the inter-conductive metal connectivity of the second electrode layer 132. This may cause floating to occur at the interface between the first electrode layer 131 and the second electrode layer 132.

[0054] If the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion 132a exceeds 50% in at least a portion of the cross-section of the second electrode layer 132, excess tin (Sn) in the conductive portion 132a can dissolve to the outer surface of the second electrode layer 132. This can prevent the formation of a uniform plating layer on the second electrode layer 132, potentially degrading the mounting characteristics.

[0055] For example, Ag3Sn, an Ag-Sn alloy, is formed by the reaction of silver (Ag) and tin (Sn) in an atomic ratio of 3:1, while Cu6Sn5 is formed by the reaction of copper (Cu) and tin (Sn) in an atomic ratio of 6:5. In other words, the amount of tin (Sn) consumed when Ag3Sn is formed is less than the amount of tin (Sn) consumed when Cu6Sn5 and the like are formed. As a result, when the proportion of the Ag-Sn alloy is very high, silver (Ag), which has a high reactivity with tin (Sn), preferentially forms the Ag-Sn alloy, generating excess tin (Sn) within the conductive part 132a, which can then dissolve onto the outer surface of the second electrode layer 132.

[0056] As an example of a method for measuring the area of ​​the conductive portion 132a and the Ag-Sn alloy, the second electrode layer 132 is polished in the first and second directions to half its length in the third direction. Then, using the center point in the first direction of the second electrode layer 132 located on the third surface 3 and fourth surface 4 of the main body as a reference, a region of 60 μm × 20 μm (E region) is imaged using a scanning electron microscope (SEM), and the area can be measured via the ImageJ program.

[0057] In this case, the conductive portion 132a includes a plurality of metal particles 132a1 and a connecting portion 132a2 connected to the plurality of metal particles, and the Ag-Sn alloy can be included in the connecting portion 132a2.

[0058] The connecting portion 132a2 may further include a first intermetallic compound, and the Ag-Sn alloy and the first intermetallic compound may refer to an intermetallic compound formed when some of the multiple metal particles 132a1 inside the second electrode layer 132 react with tin (Sn) or a tin (Sn) alloy.

[0059] Therefore, the Ag-Sn alloy and the first intermetallic compound are formed inside the second electrode layer 132, and a connecting portion 132a2 can be formed with the remaining tin (Sn) or tin (Sn) alloy after the intermetallic compound has been formed, via metallic bonding.

[0060] For example, the Ag-Sn alloy described above may be Ag3Sn formed by the interaction of silver (Ag) and tin (Sn) contained in the conductive resin composition forming the second electrode layer 132. Furthermore, the first intermetallic compound may include one or more of Cu3Sn and Cu6Sn5, which are formed by the interaction of copper (Cu) and tin (Sn) contained in the conductive resin composition forming the second electrode layer 132.

[0061] As a result, the plurality of metal particles 131a1 may include at least one of silver (Ag) and silver (Ag) coated copper (Cu), and may further include at least one of copper (Cu) and tin (Sn) coated copper (Cu). Furthermore, the connecting portion 132a2 may include at least one of tin (Sn) and tin (Sn) alloy.

[0062] In one embodiment of the present invention, at least a portion of the connecting portion 132a2 can be in direct contact with at least a portion of the first electrode layer 131. This improves mechanical and electrical connectivity through intermetallic bonding between the conductive metal contained in the first electrode layer 131 and the connecting portion 132a2 of the second electrode layer 132.

[0063] In one embodiment of the present invention, the external electrode 130 may include third electrode layers 133 and 134 disposed on the second electrode layer 132. In this case, the third electrode layers 133 and 134 may be plating layers.

[0064] The third electrode layers 133 and 134 described above play a role in improving the mounting characteristics of the stacked electronic component 100. The third electrode layers 133 and 134 may contain one or more of Ni, Sn, Cu, Pd, and alloys thereof, and may consist of multiple layers.

[0065] In this configuration, at least a portion of the connecting portion 132a2 can directly contact at least a portion of the first electrode layer 131 and at least a portion of the third electrode layers 133 and 134. This further improves the electrical connectivity and mechanical coupling force between the first electrode layer 131, the second electrode layer 132, and the third electrode layers 133 and 134.

[0066] In one embodiment of the present invention, the third electrode layers 133 and 134 may include a nickel (Ni) plated layer 133 and a tin (Sn) plated layer 134 that are sequentially laminated on the second electrode layer 132.

[0067] At this time, the nickel plating layer 133 can be in contact with the connecting portion 132a2 and the resin 132b of the second electrode layer 132. The nickel plating layer 133 can play a role in preventing the solder from melting when mounting the multilayer electronic component 100.

[0068] Furthermore, the tin plating layer 134 formed on the nickel plating layer 133 can play a role in improving the wettability of the solder when mounting the multilayer electronic component 100.

[0069] Referring to Figure 4, in one embodiment of the present invention, an interface layer 135 formed between the first electrode layer 131 and the second electrode layer 132 and containing a second intermetallic compound may be further included.

[0070] Here, the second intermetallic compound can refer to an intermetallic compound formed by the reaction of a conductive metal contained in the first electrode layer 131 and tin (Sn) or a tin (Sn) alloy contained in the second electrode layer 132.

[0071] For example, the second intermetallic compound can be Cu3Sn, which is formed by the interaction of copper (Cu) contained in the first electrode layer 131 and tin (Sn) contained in the second electrode layer 132. The interface layer 135 can be formed by the diffusion of tin (Sn) into the first electrode layer 131 during the process of applying and drying the conductive resin composition and then curing it with heat to form the second electrode layer 132.

[0072] The interface layer 135 is formed at the interface between the first electrode layer 131 and the second electrode layer 132, and by containing the second intermetallic compound, it can play a role in connecting the first electrode layer 131 and the connecting portion 132a2, thereby ensuring excellent mechanical and electrical connectivity between the first electrode layer 131 and the second electrode layer 132.

[0073] In this case, the interface layer 135 can be arranged in the form of multiple islands, and these multiple islands can be in the form of layers.

[0074] On the other hand, referring to Figure 5, it is possible that the multiple metal particles described above have all reacted with the tin (Sn) or tin (Sn) alloy contained in the conductive resin composition forming the second electrode layer 232 and are therefore not present in the second electrode layer 232.

[0075] Accordingly, in one embodiment of the present invention, the second electrode layer 232 may include a conductive portion 232a containing an Ag-Sn alloy and a resin 232b, and the conductive portion 232a may further include a first intermetallic compound. That is, it may not contain the plurality of metal particles. The conductive portion 232a has a network structure in which the Ag-Sn alloy and the first intermetallic compound are interconnected, thereby improving the mechanical and electrical connectivity of the second electrode layer 232.

[0076] In this case, the Ag-Sn alloy can be Ag3Sn formed by the interaction of silver (Ag) and tin (Sn) contained in the conductive resin composition forming the second electrode layer 232. Furthermore, the first intermetallic compound can include one or more of Cu3Sn and Cu6Sn5, which are formed by the interaction of copper (Cu) and tin (Sn) contained in the conductive resin composition forming the second electrode layer 232. In addition, the conductive portion 232a can include at least one of tin (Sn) and a tin (Sn) alloy.

[0077] The following describes in detail a method for manufacturing a stacked electronic component according to one embodiment of the present invention. However, the present invention is not limited thereto, and any explanations of the manufacturing method of the stacked electronic component of this embodiment that overlap with the explanation of the stacked electronic component described above will be omitted.

[0078] A method for manufacturing a stacked electronic component according to one embodiment of the present invention involves first applying and drying a slurry containing a powder such as barium titanate (BaTiO3) onto a carrier film to provide a plurality of ceramic green sheets.

[0079] The above-mentioned ceramic green sheet is produced by mixing ceramic powder, a binder, and a solvent to create a slurry, and then fabricating the slurry into a sheet with a thickness of several micrometers using a doctor blade method or similar.

[0080] Next, a conductive paste for internal electrodes containing a conductive metal such as nickel (Ni) is applied to the ceramic green sheet using a screen printing method or the like to form the internal electrodes.

[0081] After this, multiple layers of ceramic green sheets with printed internal electrodes are laminated, and then multiple layers of ceramic green sheets without printed internal electrodes are laminated on the upper and lower surfaces of the laminate before firing, thereby forming the main body including the dielectric layer and cover.

[0082] Next, a first electrode layer is formed on the third and fourth surfaces of the main body so as to be connected to a first internal electrode and a second internal electrode, one end of which is exposed on the third and fourth surfaces of the main body.

[0083] The first electrode layer described above can be formed by applying a conductive paste for external electrodes, which includes a conductive metal such as copper (Cu) and glass, to one and the other surface of the main body.

[0084] The first electrode layer described above can be formed by a dipping method, but is not limited thereto. The first electrode layer can also be formed by a method of attaching or transferring a sheet, an electroless plating method, or a sputtering method.

[0085] Next, a conductive resin composition containing multiple metal particles and resin can be applied to the first electrode layer and subjected to curing heat treatment to form a second electrode layer containing a conductive portion and resin. In this case, the conductive resin composition may contain Sn-based solder powder.

[0086] The above-mentioned plurality of metal particles may include at least one of silver (Ag) and silver (Ag)-coated copper (Cu), and the resin may include an electrically insulating thermosetting resin. In this case, the thermosetting resin may be, for example, an epoxy resin, and may be a bisphenol A resin, glycol epoxy resin, novolac epoxy resin, or a derivative thereof with a small molecular weight and liquid at room temperature, but the present invention is not limited thereto.

[0087] For example, the above conductive resin composition can be manufactured by mixing Ag powder, Cu powder, Ag-coated Cu powder, Sn-based solder powder, and a thermosetting resin, and then dispersing them using a 3-roll mill. Examples of Sn-based solder powders include Sn and Sn. 96.5 Ag 3.0 Cu 0.5 Sn 42 Bi 58 , and Sn 72 Bi 28 The present invention may contain at least one of the above, and the size of the Ag particles contained in the Ag powder may be 0.5 to 3 μm, but the present invention is not limited thereto.

[0088] At this time, the conductive resin composition can be applied to the first electrode layer, dried, and cured to form an Ag-Sn alloy and a first intermetallic compound. In the curing process, all of the metal particles may react with tin (Sn) or the tin (Sn) alloy and therefore may not be present in the second electrode layer.

[0089] Furthermore, during the curing process, the Sn-based solder contained in the conductive resin composition and the Cu contained in the first electrode layer react to form a second intermetallic compound, thereby forming an interface layer containing the second intermetallic compound between the first electrode layer and the second electrode layer.

[0090] The area ratio of the Ag-Sn alloy contained in the second electrode layer can be controlled by adjusting the amount of Ag powder, the amount of Sn solder powder, and the amount of Ag-coated Cu powder.

[0091] Furthermore, the process may further include the step of forming a third electrode layer on the second electrode layer. For example, a nickel plating layer may be formed on the second electrode layer, and a tin plating layer may be formed on the nickel plating layer.

[0092] [Examples] After measuring the presence or absence of floating and Sn leaching within the second electrode layer 132 according to the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion 132a contained in the second electrode layer 132, the results were recorded in Table 1 below.

[0093] Figure 6 is an image of a cross-section of the second electrode layer 132 taken using a field emission scanning electron microscope (FE-SEM). More specifically, it is an image of a portion of the second electrode layer 132 located on the third surface 3 of the main body, with the center point of the second electrode layer 132 in the first direction as the reference point, after polishing the second electrode layer 132 in the first direction to a point half the length in the third direction.

[0094] At this time, the above image was analyzed for its components using energy dispersive X-ray spectroscopy (EDS), and it was confirmed that the relatively bright regions in the conductive part 132a were Ag-Sn alloy, i.e., Ag3Sn. In addition, it was confirmed that the relatively dark regions in the conductive part 132a were Cu3Sn and Cu6Sn5.

[0095] Referring to Figure 7a, in the above SEM image, the second electrode layer 132 located on the third surface 3 of the main body is shown with reference to the center point in the first and second directions, and the region (E region) is shown with length in the first direction × length in the second direction = 60 μm × 20 μm, and the region in which the conductive part 132a is formed is colored.

[0096] Referring to Figure 7b, the ImageJ program processed the region where the conductive portion 132a was formed into monochrome, displaying the conductive portion 132a in black and the resin 132b in white. At this time, voids within the first electrode layer 131 and the second electrode layer 132 were not displayed in black. After this, the area occupied by the conductive portion 132a in the total area of ​​region E was measured.

[0097] Referring to Figure 8a, as described above, in the above SEM image, a region of 60 μm × 20 μm (region E) is shown based on the midpoint of the first and second directions of the second electrode layer 132 located on the third surface 3 of the main body, with the length in the first direction × the length in the second direction = 60 μm × 20 μm, and the region where the Ag-Sn alloy was formed is colored.

[0098] Referring to Figure 8b, the region where the Ag-Sn alloy was formed was processed in monochrome using the ImageJ program, displaying the Ag-Sn alloy in black and the other regions in white. At this time, voids within the first electrode layer 131 and the second electrode layer 132 are not displayed in black. After this, the area occupied by the Ag-Sn alloy in the total area of ​​region E was measured. Subsequently, the area ratio (S) of the Ag-Sn alloy to the area of ​​the conductive part 132a in the area of ​​region E is shown in Table 1.

[0099] To determine whether or not delamination occurred, each sample was mounted in the stacking direction and horizontally or vertically, and then reflow soldering was applied to the mounted samples. After this, the mounted samples on the substrate were cut in the first and second directions, and both sides of the external electrode for each sample were photographed using X-ray. If a bright band was present on the external electrode, it was evaluated as delamination had occurred, and for each sample number of 30 samples, the results were indicated as either delamination occurred (NG) or not (OK).

[0100] To determine whether or not Sn elution occurred, for each sample before the formation of the third electrode layers 133 and 134, the external electrode was cut in the first and second directions, and both sides of the external electrode for each sample were imaged using SEM to check for the presence or absence of Sn elution on the outer surface of the second electrode layer 132. For 30 samples per sample number, the results were indicated as either Sn elution occurred (NG) or not (OK).

[0101] [Table 1] * indicates a comparative example

[0102] In the case of samples 1 to 4, the area ratio (S) of the Ag-Sn alloy to the area of ​​the conductive part 132a was less than 3%, and it was confirmed that a gap occurred between the first electrode layer 131 and the second electrode layer 132.

[0103] In the case of samples 10 to 13, the area ratio (S) of the Ag-Sn alloy to the area of ​​the conductive portion 132a exceeded 50%, and it was confirmed that the excess tin (Sn) in the conductive portion 132a dissolved to the outer surface of the second electrode layer 132, as shown in Figure 9.

[0104] In the case of samples 5 to 9, it was confirmed that the area ratio (S) of the Ag-Sn alloy to the area of ​​the conductive part 132a was within the range of 3 to 50%, which suppressed the occurrence of floating particles and prevented the leaching of excess Sn.

[0105] Although embodiments of the present invention have been described in detail above, it will be clear to those with ordinary skill in the art that the scope of the present invention is not limited thereto, and that various modifications and variations are possible without departing from the technical idea of ​​the present invention as described in the claims. [Explanation of Symbols]

[0106] 100 Stacked Electronic Components 110 Main Unit 112 Upper cover section 113 Lower cover section 111 Dielectric layer 121 1st internal electrode 122 2nd internal electrode 130 1st external electrode 140 2nd external electrode 131, 141 1st electrode layer 132, 142 Second electrode layer 133, 134, 143, 144, 233, 234 Third electrode layer 133, 143, 233 Nickel (Ni) plating layer 134, 144, 234 Tin (Sn) plating layer 132a, 232a Conductive part 132b, 232b resin 132a1 Metal particles 132a2 Connecting part 135 Interface layer

Claims

1. A body including a dielectric layer and a plurality of internal electrodes stacked with the dielectric layer in between, and an external electrode disposed on the body, The aforementioned external electrode is A first electrode layer connected to the internal electrode, The first electrode layer is disposed on the first electrode layer and includes a conductive portion containing an Ag-Sn alloy and a second electrode layer containing a resin, A multilayer electronic component in which, in at least a portion of the cross-section of the second electrode layer, the area ratio of the Ag-Sn alloy to the area of ​​the conductive portion is 3 to 50%.

2. The conductive portion includes a plurality of metal particles and connecting portions connected to the plurality of metal particles, The stacked electronic component according to claim 1, wherein the Ag-Sn alloy is included in the connecting portion.

3. The multilayer electronic component according to claim 2, wherein the connecting portion further comprises a first intermetallic compound.

4. The first intermetallic compound is Cu ３ Sn and Cu ６ Sn ５ A stacked electronic component according to claim 3, comprising one or more of the above.

5. The stacked electronic component according to claim 2, wherein at least a portion of the connecting portion is in direct contact with at least a portion of the first electrode layer.

6. The stacked electronic component according to any one of claims 1 to 5, further comprising an interface layer formed between the first electrode layer and the second electrode layer and containing a second intermetallic compound.

7. The second intermetallic compound is Cu ３ The stacked electronic component according to claim 6, wherein the material is Sn.

8. The laminated electronic component according to claim 6 or 7, wherein the interface layer is in the shape of a plurality of islands.

9. The multilayer electronic component according to claim 1, wherein the conductive portion further comprises a first intermetallic compound.

10. The first intermetallic compound is Cu ３ Sn and Cu ６ Sn ５ A stacked electronic component according to claim 9, comprising one or more of the above.

11. The stacked electronic component according to any one of claims 1 to 10, wherein the external electrode further comprises a third electrode layer disposed on the second electrode layer.

12. The stacked electronic component according to claim 11, wherein the third electrode layer includes a nickel (Ni) plated layer and a tin (Sn) plated layer stacked sequentially on the second electrode layer.

13. The multilayer electronic component according to claim 2, wherein the plurality of metal particles include at least one of silver (Ag) and silver (Ag) coated copper (Cu).

14. The multilayer electronic component according to claim 2, wherein the connecting portion includes at least one of tin (Sn) and a tin (Sn) alloy.

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