Patent Publication Number: US-2023154684-A1

Title: Multilayer electronic component

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is the continuation application of U.S. Pat. Application No. 15/931,042 filed on May 13, 2020, which claims benefit of priority to Korean Patent Application No. 10-2020-0021455 filed on Feb. 21, 2020 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a multilayer electronic component. 
     BACKGROUND 
     A multilayer ceramic capacitor (MLCC), a type of multilayer electronic component, may be a chip-type condenser mounted on the printed circuit boards of various electronic products such as imaging devices including liquid crystal displays (LCDs), plasma display panels (PDPs), and the like, and computers, smartphones, mobile phones, and the like, serving to charge or discharge electricity therein or therefrom. 
     Such multilayer ceramic capacitors may be used as components of various electronic devices due to their relatively small size, relatively high capacitance, and relative ease of mounting. As various electronic devices such as computers, mobile devices, or the like are miniaturized and increased in terms of output, demand for miniaturization and high capacitance of multilayer ceramic capacitors are increasing. 
     With trend for miniaturization and high capacitance in MLCC, the importance of increasing an effective volume ratio of MLCC (ratio of volume contributing capacitance to total volume) is increasing. 
     Conventionally, when forming an external electrode, a process of dipping a surface to which an internal electrode of a body is exposed into a paste may mainly be used by using a paste containing a conductive metal. 
     However, the external electrode formed by the dipping process may be not uniform in terms of thickness, and the external electrode may be formed to be excessively thin at corner portions of the body, while the external electrode may be formed to be excessively thick in other portions. Due thereto, there are problems that it is difficult to secure a high effective volume ratio, and a plating solution may penetrate into the body to decrease reliability of the MLCC, when the plating layer is formed on the external electrode in order to increase connectivity and mountability of the MLCC. 
     SUMMARY 
     An aspect of the present disclosure is to provide a multilayer electronic component having improved reliability for moisture resistance. 
     Another aspect of the present disclosure is to provide a multilayer electronic component having improved capacitance per unit volume. 
     However, the objects of the present disclosure are not limited to the above, and will be more easily understood in the course of describing the specific embodiment of the present disclosure. 
     According to an aspect of the present disclosure, a multilayer electronic component includes a body including a dielectric layer, and a first internal electrode and a second internal electrode alternately disposed in a first direction with the dielectric layer interposed therebetween, and including a first surface and a second surface opposing each other in the first direction, a third surface and a fourth surface connected to the first and second surfaces and opposing each other in a second direction, and a fifth surface and a sixth surface connected to the first to fourth surfaces and opposing each other in a third direction; a first external electrode including a  1   a  electrode layer disposed on the third surface, a  1   b  electrode layer disposed on the  1   a  electrode layer, a  1   c  electrode layer disposed on the first and second surfaces, and a  1   d  electrode layer disposed on the  1   b  electrode layer, and disposed to extend onto a portion of the  1   c  electrode layer; and a second external electrode including a  2   a  electrode layer disposed on the fourth surface, a  2   b  electrode layer disposed on the  2   a  electrode layer, a  2   c  electrode layer disposed on the first and second surfaces, and a  2   d  electrode layer disposed on the  2   b  electrode layer, and disposed to extend onto a portion of the  2   c  electrode layer. 
     According to an aspect of the present disclosure, a method for manufacturing a multilayer electronic component includes forming a body including a dielectric layer, and a first internal electrode and a second internal electrode alternately disposed in a first direction with the dielectric layer interposed therebetween, and including a first surface and a second surface opposing each other in the first direction, a third surface and a fourth surface connected to the first and second surfaces and opposing each other in a second direction, and a fifth surface and a sixth surface connected to the first to fourth surfaces and opposing each other in a third direction; forming, by a transfer process, a first electrode layer on one of the third and fourth surfaces and a second electrode layer on the first electrode layer; forming, by a first dipping process, a third electrode layer on the first surface, the second surface, and the one of the third and fourth surfaces to cover the second electrode layer and portions of the first and second surfaces; removing a portion of the third electrode layer formed on the one of the third and fourth surfaces; and forming, by a second dipping process, a fourth electrode layer to cover a remaining portion of the third electrode layer and to cover the second electrode layer. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    schematically illustrates a perspective view of a multilayer electronic component according to an embodiment of the present disclosure. 
         FIG.  2    schematically illustrates a perspective view of a body of a multilayer electronic component according to an embodiment of the present disclosure. 
         FIG.  3    is an exploded perspective view schematically illustrating an exploded body in which the dielectric layer and the internal electrode of  FIG.  2    are stacked. 
         FIG.  4    is a cross-sectional view taken along line I-I′ of  FIG.  1   . 
         FIG.  5    is an enlarged view illustrating region P of  FIG.  4   . 
         FIG.  6    is a view of Comparative Example, and illustrates region P 1  corresponding to the region P of  FIG.  4   . 
         FIG.  7    is a photograph in which a cross-sectional view of a multilayer electronic component is captured, and a photograph in which an outer surface of a corner portion is captured, according to an embodiment of the present disclosure. 
         FIG.  8    is a photograph in which a cross-sectional view of a multilayer electronic component is captured, and a photograph in which an outer surface of a corner portion is captured, according to Comparative Example. 
         FIG.  9    is a view illustrating an operation of forming a 1a electrode layer by a transfer process. 
         FIG.  10    is a view illustrating an operation of forming a 1b electrode layer by a transfer process. 
         FIGS.  11  and  12    are views illustrating a process of forming a 1c electrode layer. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described with reference to specific embodiments and the accompanying drawings. However, embodiments of the present disclosure may be modified into various other forms, and the scope of the present disclosure is not limited to the embodiments described below. Further, embodiments of the present disclosure may be provided for a more complete description of the present disclosure to the ordinary artisan. Therefore, shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings may be the same elements. 
     In the drawings, portions not related to the description will be omitted for clarification of the present disclosure, and a thickness may be enlarged to clearly show layers and regions. The same reference numerals will be used to designate the same components in the same reference numerals. Further, throughout the specification, when an element is referred to as “comprising” or “including” an element, it means that the element may further include other elements as well, without departing from the other elements, unless specifically stated otherwise. 
     A value used to describe a parameter such as a 1-D dimension of an element including, but not limited to, “length,” “width,” “thickness,” diameter,” “distance,” “gap,” and/or “size,” a 2-D dimension of an element including, but not limited to, “area” and/or “size,” a 3-D dimension of an element including, but not limited to, “volume” and/or “size”, and a property of an element including, not limited to, “roughness,” “density,” “weight,” “weight ratio,” and/or “molar ratio” may be obtained by the method(s) and/or the tool(s) described in the present disclosure. The present disclosure, however, is not limited thereto. Other methods and/or tools appreciated by one of ordinary skill in the art, even if not described in the present disclosure, may also be used. 
     In the drawings, an X direction may be defined as a second direction, an L direction, or a longitudinal direction, a Y direction may be defined as a third direction, a W direction, or a width direction of a body, and a Z direction may be defined as a first direction, a stacking direction, a T direction, or a thickness direction. 
     Multilayer Electronic Component 
       FIG.  1    schematically illustrates a perspective view of a multilayer electronic component according to an embodiment of the present disclosure. 
       FIG.  2    schematically illustrates a perspective view of a body of a multilayer electronic component according to an embodiment of the present disclosure. 
       FIG.  3    is an exploded perspective view schematically illustrating an exploded body in which the dielectric layer and the internal electrode of  FIG.  2    are stacked. 
       FIG.  4    is a cross-sectional view taken along line I-I′ of  FIG.  1   . 
       FIG.  5    is an enlarged view illustrating region P of  FIG.  4   . 
     Hereinafter, a multilayer electronic component  100  according to an embodiment of the present disclosure will be described with reference to  FIGS.  1  to  5   . 
     The multilayer electronic component  100  according to an exemplary embodiment of the present disclosure may include a body  110  including a dielectric layer  111 , and a first internal electrode  121  and a second internal electrode  122  alternately disposed in a first direction (a Z direction) with the dielectric layer  111  interposed therebetween, and including a first surface  1  and a second surface  2  opposing each other in the first direction, a third surface  3  and a fourth surface  4  connected to the first and second surfaces and opposing each other in a second direction (an X direction), and a fifth surface  5  and a sixth surface  6  connected to the first to fourth surfaces  1  to  4  and opposing each other in a third direction (a Y direction); a first external electrode  131  including a  1   a  electrode layer  131   a  disposed on the third surface, a  1   b  electrode layer  131   b  disposed on the 1a electrode layer, a  1   c  electrode layer  131   c  disposed on the first and second surfaces  1  and  2 , and a  1   d  electrode layer  131   d  disposed on the  1   b  electrode layer, and disposed to extend onto a portion of the  1   c  electrode layer; and a second external electrode  132  including a  2   a  electrode layer  132   a  disposed on the fourth surface, a  2   b  electrode layer  132   b  disposed on the  2   a  electrode layer, a  2   c  electrode layer  132   c  disposed on the first and second surfaces  1  and  2 , and a  2   d  electrode layer  132   d  disposed on the  2   b  electrode layer, and disposed to extend onto a portion of the 2c electrode layer. 
     In the body  110 , the dielectric layers  111  and the internal electrodes  121  and  122  may be alternately stacked. 
     A specific shape of the body  110  is not particularly limited, but as illustrated, the body  110  may be formed to have a hexahedral or similar shape. Due to shrinkage of ceramic powder contained in the body  110  during a firing process, the body  110  may not have a perfectly hexahedral shape with completely straight lines, but may have a substantially hexahedral shape. 
     The body  110  may have the first and second surfaces  1  and  2  opposing each other in the first direction (the Z direction), the third and fourth surfaces  3  and  4  connected to the first and second surfaces  1  and  2  and opposing each other in the second direction (the X direction), and the fifth and sixth surfaces  5  and  6  connected to the first and second surfaces  1  and  2 , connected to the third and fourth surfaces  3  and  4 , and opposing each other in the third direction (the Y direction). 
     A plurality of dielectric layers  111  forming the body  110  may be in a fired state, and a boundary between adjacent dielectric layers  111  may be integrated to such an extent that it is difficult to identify the device without using a scanning electron microscope (SEM). 
     According to an embodiment of the present disclosure, a raw material for forming the dielectric layer  111  is not particularly limited, as long as sufficient capacitance may be obtained. For example, a barium titanate-based material, a lead composite perovskite-based material, a strontium titanate-based material, or the like may be used. The barium titanate-based material may include a BaTiO 3 -based ceramic powder, and examples of the ceramic powder may include BaTiO 3 , or (Ba 1-x Ca x ) TiO 3 , Ba (Ti 1-y Ca y ) O 3 , (Ba 1-x Ca x ) (Ti 1-y Zr y ) O 3 , or Ba (Ti 1-y Zr y ) O 3 , in which calcium (Ca), zirconium (Zr), or the like is partially dissolved into BaTiO 3 , or the like. 
     As the material for forming the dielectric layer  111 , various ceramic additives, organic solvents, plasticizers, binders, dispersants, or the like may be added to powder particles such as barium titanate (BaTiO 3 ) according to the purpose of the present disclosure. 
     The body  110  may include a capacitance forming portion disposed in the body  110  and including the first internal electrode  121  and the second internal electrode  122  disposed to oppose each other with the dielectric layer  111  interposed therebetween, to form capacitance; and an upper protective layer  112  and a lower protective layer  113  formed on the capacitance forming portion, respectively, in upward and downward directions. 
     The capacitance forming portion may be a portion for contributing to formation of capacitance of the capacitor, and may be formed by repeatedly stacking the plurality of first and second internal electrodes  121  and  122  with the dielectric layer  111  interposed therebetween. 
     The upper protective layer  112  and the lower protective layer  113  may be formed by stacking a single dielectric layer or two or more dielectric layers on upper and lower surfaces of the capacitance forming portion, respectively, in a vertical direction, and may basically play a role in preventing damage to the internal electrodes due to physical or chemical stress. 
     The upper protective layer  112  and the lower protective layer  113  may not include an internal electrode, and may include the same material as the dielectric layer  111 . 
     The internal electrodes  121  and  122  may include first and second internal electrodes  121  and  122 . The first and second internal electrodes  121  and  122  may be alternately arranged to oppose each other with the dielectric layer interposed therebetween, and may be exposed from the third and fourth surfaces  3  and  4  of the body  110 , respectively. 
     Referring to  FIGS.  2  to  4   , the first internal electrode  121  may be spaced apart from the fourth surface  4  and may be exposed from the third surface  3 , and the second internal electrode  122  may be spaced apart from the third surface  3  and may be exposed from the fourth surface  4 . 
     In this case, the first and second internal electrodes  121  and  122  may be electrically separated from each other by the dielectric layer  111  interposed therebetween. 
     Referring to  FIG.  3   , the body  110  may be formed by alternately stacking a ceramic green sheet on which the first internal electrode  121  is printed and a ceramic green sheet on which the second internal electrode  122  is printed, and then firing the stacked ceramic green sheet. 
     A material for forming the internal electrodes  121  and  122  is not particularly limited. For example, the internal electrodes  121  and  122  may be formed by printing a conductive paste for internal electrodes containing 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, on a ceramic green sheet. 
     As a printing method of the conductive paste for internal electrodes, a screen-printing method or a gravure printing method may be used, but the present disclosure is not limited thereto. 
     In order to achieve miniaturization and high capacitance of the multilayer ceramic capacitor, the number of stacked bodies should be increased by reducing thicknesses of the dielectric layer and the internal electrode, and characteristics of insulation resistance, breakdown voltage, or the like may be deteriorated, as the thicknesses of the dielectric layer and the internal electrode become thinner. 
     Therefore, as the thicknesses of the dielectric layer and the internal electrode become thinner, an effect of improving reliability according to the present disclosure may be increased. 
     Particularly, when a thickness (te) of the internal electrodes  121  and  122  or a thickness (td) of the dielectric layer  111  is 0.41 µm or less, effects of improving high temperature lifetime characteristics and TCC characteristics according to the present disclosure may be remarkable improved. 
     The thickness (te) of the internal electrodes  121  and  122  may refer to an average thickness of the first and second internal electrodes  121  and  122 . 
     The thickness (te) of the internal electrodes  121  and  122  may be measured by scanning an image of a cross-section in the third and first directions (an L-T cross-section) of the body  110  by a scanning electron microscope (SEM). 
     For example, on the basis of a reference internal electrode layer at a point at which a center line in the longitudinal direction of the body and a center line in the thickness direction of the body meet, a thickness (te) of the internal electrodes  121  and  122  may be determined by defining two points to the left and two points to the right from a reference center point in the reference internal electrode layer at equal intervals, measuring a thickness of each of the defined points, and obtaining an average value therefrom, for five internal electrode layers including the reference internal electrode layer, and two upper internal electrode layers and two lower internal electrode layers, respectively arranged on and below the reference internal electrode layer, among the internal electrode layers extracted from an image of a cross-section in the third and first directions (an L-T cross-section) of the body  110 , cut in a central portion of the body  110  in the width direction, scanned by a scanning electron microscope (SEM). 
     For example, since a thickness at the reference center point in the reference internal electrode layer at a point at which a center line in the longitudinal direction of the body and a center line in the thickness direction of the body meet, and a thickness at each of the two points to the left and right from the reference center point at equal intervals (e.g., each 500 nm), for the above five internal electrode layers, may be measured, the thickness (te) of the internal electrodes  121  and  122  may be determined as an average value of the thicknesses of the total 25 points. 
     The thickness (td) of the dielectric layer  111  may refer to an average thickness of the dielectric layer  111  disposed between the first and second internal electrodes  121  and  122 . 
     Similar to the thickness (te) of the internal electrode, the thickness (td) of the dielectric layer  111  may be measured by scanning an image of a cross-section in the third and first directions (an L-T cross-section) of the body  110  by a scanning electron microscope (SEM). 
     For example, on the basis of a reference dielectric layer at a point at which a center line in the longitudinal direction of the body and a center line in the thickness direction of the body meet, a thickness (td) of the dielectric layer  111  may be determined by defining two points to the left and two points to the right from a reference center point in the reference dielectric layer at equal intervals, measuring a thickness of each of the defined points, and obtaining an average value therefrom, for five dielectric layers including the reference dielectric layer, and two upper dielectric layers and two lower dielectric layers, respectively arranged on and below the reference dielectric layer, among the dielectric layers extracted from an image of a cross-section in the third and first directions (an L-T cross-section) of the body  110 , cut in a central portion of the body  110  in the width direction, scanned by a scanning electron microscope (SEM). 
     For example, since a thickness at the reference center point in the reference dielectric layer at a point at which a center line in the longitudinal direction of the body and a center line in the thickness direction of the body meet, and a thickness at each of the two points to the left and right from the reference center point at equal intervals (e.g., each 500 nm), for the above five dielectric layers, may be measured, the thickness (td) of the dielectric layer  111  may be determined as an average value of the thicknesses of the total 25 points. 
     The external electrodes  131  and  132  may be arranged on the body  110 , and may be connected to the internal electrodes  121  and  122 , respectively. In addition, the external electrodes  131  and  132  may include first and second external electrodes  131  and  132  disposed on the third and fourth surfaces  3  and  4  of the body  110 , respectively, and connected to the first and second internal electrodes  121  and  122 , respectively. 
     In this embodiment, a structure in which the multilayer electronic component  100  has two external electrodes  131  and  132  may be described, but the number, shape, and the like of the external electrodes  131  and  132  may be changed, depending on shapes of the internal electrodes  121  and  122 , or other purposes. 
     The first external electrode  131  may include the  1   a  electrode layer  131   a  disposed on the third surface of the body  110 , the  1   b  electrode layer  131   b  disposed on the  1   a  electrode layer, the  1   c  electrode layer  131   c  disposed on the first and second surfaces  1  and  2  of the body  110 , and the  1   d  electrode layer  131   d  disposed on the  1   b  electrode layer, and disposed to extend onto a portion of the  1   c  electrode layer. 
     The second external electrode  132  may include the  2   a  electrode layer  132   a  disposed on the fourth surface of the body  110 , the  2   b  electrode layer  132   b  disposed on the  2   a  electrode layer, the  2   c  electrode layer  132   c  disposed on the first and second surfaces  1  and  2  of the body  110 , and the  2   d  electrode layer  132   d  disposed on the  2   b  electrode layer, and disposed to extend onto a portion of the  2   c  electrode layer. 
     Hereinafter, the first external electrode  131  will be mainly described, but the same may be applied to the second external electrode  132 . 
     Conventionally, external electrodes were formed by dipping exposed surfaces of first and second internal electrodes, respectively, into a conductive paste. 
     The external electrode formed by a dipping process, as above, may be not uniform in thickness of the external electrode, and the external electrode may be formed too thin in a corner portion of the body, while the external electrode may be formed too thick in the other portion of the body. 
     When the external electrode is formed thin in the corner portion of the body, the external electrode may act as a water penetration path to reduce reliability for moisture resistance. Therefore, the external electrode should be formed thicker to secure the external electrode in the corner portion to a predetermined thickness or more. Therefore, there are problems in that a capacitance or mounting density per unit volume was lowered, or plating defects due to glass beading or blister occur. 
     Therefore, there has been an attempt to form an external electrode thin by transferring the electrode sheet to the body. According to this, since the external electrode is thinned, it was effective in terms of improvement in capacitance per unit volume, but reliability for moisture resistance is lowered because a thickness of the external electrode at the corner is too thin. 
     Therefore, the present disclosure is to provide a multilayer electronic component, in which the external electrode may be thinned to secure capacitance per unit volume, while securing the external electrode at a corner in a specific thickness or higher with improved reliability for moisture resistance. 
     As illustrated in  FIG.  4   , when the first external electrode  131  is divided into portions according to a position to be disposed, the first external electrode  131  may include a first connection portion A 1  disposed on the third surface  3  of the body  110 , a first band portion B 1  disposed on the first and second surfaces  1  and  2 , and a first corner portion C 1  that may be a region between the first connection portion and the first band portion. When the second external electrode  132  is divided into portions according to a position to be disposed, the second external electrode  132  may include a second connection portion A 2  disposed on the fourth surface  4  of the body  110 , a second band portion B 2  disposed on the first and second surfaces  1  and  2 , a second corner portion C 2  that may be a region between the second connection portion and the second band portion. Further, the first and second band portions B 1  and B 2  may be arranged on the fifth and sixth surfaces  5  and  6 . 
     Referring to  FIG.  5   , according to an embodiment of the present disclosure, when a paste is applied or dipped in order to form the fourth electrode layer  131   d , the first electrode layer  131   a  and the first electrode layer  131   b  may be arranged on the first connection portion A 1 , and the third electrode layer  131   c  may be disposed on the first band portion B 1 , to sufficiently secure a region in which a paste is applied to a corner portion of the body, such that the corner portion C 1  of the external electrode have a thickness (D1), greater than a certain thickness. 
       FIG.  6    is a view of Comparative Example, and illustrates region P 1  corresponding to the region P of  FIG.  4   . In the Comparative Example, when only the first electrode layer  131   a  is formed on the first connection portion A 1  and the first electrode layer  131   b  is not disposed on the first connection portion A 1 , a region in which a paste is applied to a corner portion of the body may not be sufficiently secured, and it may be difficult to sufficiently secure a thickness (D1′) of the corner portion of the external electrode. 
       FIG.  7    is a photograph (an upper photograph) in which a cross-sectional view of a multilayer electronic component is captured, and a photograph (a lower photograph) in which an outer surface of a corner portion is captured, according to an embodiment of the present disclosure. 
       FIG.  8    is a photograph (an upper photograph) in which a cross-sectional view of a multilayer electronic component is captured, and a photograph (a lower photograph) in which an outer surface of a corner portion is captured, according to Comparative Example. 
     By comparing  FIGS.  7  and  8   , a thickness of the external electrode at the corner portion may be sufficiently secured according to an embodiment of the present disclosure, and thus, it can be confirmed that the external electrode or the plating layer is not disconnected even at an outer surface of the corner portion. In the case of the Comparative Example, the thickness of the external electrode at the corner portion may be not sufficiently secured, and thus, it can be confirmed that the external electrode or the plating layer was disconnected even at the outer surface of the corner portion. 
     In addition, reliability for moisture resistance was evaluated by preparing thirty (30) sample chips having an external electrode, as Inventive Examples, according to an embodiment of the present disclosure and thirty (30) sample chips having an external electrode, as Comparative Examples, according to the Comparative Example, respectively, and applying a voltage of 4 V for 5 hours thereto at a temperature of 85° C. and a relative humidity of 85%. 
     The sample chip of Inventive Example had excellent reliability for moisture resistance, with zero (0) sample chip having insulation resistance value lowered to ⅒ or less, compared to an initial value of the insulation resistance. 
     The sample chip of Comparative Example had inferior reliability for moisture resistance, with four (4) sample chips having insulation resistance value lowered to ⅒ or less, among the thirty (30) sample chips, compared to an initial value of the insulation resistance. 
     The  1   a  electrode layer  131   a  may be disposed on the third surface  3  of the body  110 . The  1   a  electrode layer  131   a  may be connected to the first internal electrode  121  and may electrically connect the first external electrode  131  and the first internal electrode  121 . 
     The  2   a  electrode layer  132   a  may be disposed on the fourth surface  4  of the body  110 . The  2   a  electrode layer  132   a  may be connected to the second internal electrode  122  and may electrically connect the second external electrode  132  and the second internal electrode  122 . 
     The  1   a  and  2   a  electrode layers  131   a  and  132   a  may include a metal material having high electrical conductivity, and include the same metal as the internal electrodes  121  and  122  to increase electrical connectivity with the internal electrodes  121  and  122 . For example, 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 may be included. 
     The  1   a  and  2   a  electrode layers  131   a  and  132   a  may be provided in the form of a sintered electrode. In this case, the  1   a  and  2   a  electrode layers  131   a  and  132   a  before sintering may be transferred to the body  110  in a state including organic materials such as metal particles and a binder, and the organic materials or the like after sintering may be removed therefrom. 
     The  1   b  electrode layer  131   b  may be disposed on the 1a electrode layer  131   a . The  1   b  electrode layer  131   b  may electrically connect the  1   a  electrode layer  131   a  and the  1   d  electrode layer  131   d , and may secure bonding strength. In addition, the corner portion C 1  of the external electrode may perform a role of sufficiently securing a region in which paste may be applied to the corner portion of the body, together with the  1   a  electrode layer  131   a , to have a thickness (D) of a predetermined value or more. 
     The  2   b  electrode layer  132   b  may be disposed on the  2   a  electrode layer  132   a . The  2   b  electrode layer  132   b  may electrically connect the  2   a  electrode layer  132   a  and the  2   d  electrode layer  132   d , and may secure bonding strength. In addition, the corner portion C 2  of the external electrode may perform a role of sufficiently securing a region in which paste may be applied to the corner portion of the body, together with the  2   a  electrode layer  132   a , to have a thickness having a predetermined value or more. 
     The  1   b  and  2   b  electrode layers  131   b  and  132   b  may include a metal material having high electrical conductivity, and include the same metal as the  1   d  and  2   d  electrode layers  131   d  and  132   d  to increase electrical connectivity with the  1   d  and  2   d  electrode layers  131   d  and  132   d . For example, 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 may be included. 
     The  1   b  and  2   b  electrode layers  131   b  and  132   b  may be provided in the form of sintered electrodes, in a similar manner to the  1   a  and  2   a  electrode layers  131   a  and  132   a . In this case, the  1   b  and  2   b  electrode layers  131   b  and  132   b  before sintering may be transferred to the body  110  in a state including organic materials such as metal particles and a binder, and the organic materials or the like may be removed therefrom after sintering. 
     According to an embodiment of the present disclosure, the  1   a  electrode layer  131   a  may include the same metal as the first internal electrode  121 , and the  1   b  electrode layer  131   b  may include the same metal as the  1   d  electrode layer  131   d . 
     In order to sufficiently secure a region to which a paste may be applied to a corner portion of the body, a method of increasing a thickness of the first electrode layer  131   a  without disposing the first electrode layer  131   b  may be considered. In this case, bonding strength may not be sufficiently secured. Further, even when the  1   a  electrode layer  131   a  and the  1   b  electrode layer  131   b  contain the same metals, bonding strength may not be sufficiently secured. 
     When the  1   a  electrode layer  131   a  includes the same metal as the first internal electrode  121 , and the  1   b  electrode layer  131   b  includes the same metal as the  1   d  electrode layer  131   d , bonding strength with the body  110  and bonding strength with the  1   d  and  2   d  electrode layers  131   d  and  132   d  may be simultaneously secured. 
     For a more specific example, since, in general, the internal electrode may include Ni, and the  1   d  electrode layer  131   d  may include Cu, the  1   a  electrode layer  131   a  may be formed by transferring a sheet containing Ni, and the  1   b  electrode layer  131   b  may be formed by transferring a sheet containing Cu. 
     In addition, one or more additional electrode layers (not illustrated) may be further disposed between the  1   b  electrode layer  131   b  and the  1   d  electrode layer  131   d . The number of additional electrode layers is not particularly limited, but the number of additional electrode layers may be determined in consideration of bonding strength and a final thickness of the external electrode. 
     A first additional electrode layer may also be formed in the same manner as the  1   a  and  1   b  electrode layers  131   a  and  131   b . 
     The  1   c  and  2   c  electrode layers  131   c  and  132   c  may be arranged on the first and second surfaces  1  and  2  of the body  110 . The  1   c  and  2   c  electrode layers  131   c  and  132   c  may perform a role of sufficiently securing a region in which paste may be applied to the corner portion of the body, together with the  1   a  and  1   b  electrode layers  131   a  and  131   b  and the  2   a  and  2   b  electrode layers  132   a  and  132   b , to have a thickness (D) of a predetermined value or more in the corner portions C 1  and C 2  of the external electrode. In this case, the  1   c  and  2   c  electrode layers  131   c  and  132   c  may be arranged on the fifth and sixth surfaces of the body. 
     The  1   c  and  2   c  electrode layers  131   c  and  132   c  may be formed by dipping the body  110  on which the  1   a ,  1   b ,  2   a , and  2   b  electrode layers are formed in a conductive paste containing a conductive metal and glass, and removing the paste from a connection portion. 
     A conductive metal included in the  1   c  and  2   c  electrode layers  131   c  and  132   c  is not particularly limited. For example, 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 may be included. 
     The  1   d  electrode layer  131   d  may be disposed on the 1b electrode layer  131   b , and may be disposed to extend to a portion on the  1   c  electrode layer  131   c . The  2   d  electrode layer  132   d  may be disposed on the  2   b  electrode layer  132   b , and may be disposed to extend to a portion on the  2   c  electrode layer  131   c . 
     The  1   d  and  2   d  electrode layers  131   d  and  132   d  may be formed by dipping the body  110  on which the  1   a ,  1   b ,  1   c ,  2   a ,  2   b , and  2   c  electrode layers are formed to a conductive paste containing a conductive metal and glass, and removing the paste on a connection portion. 
     A conductive metal included in the  1   d  and  2   d  electrode layers  131   d  and  132   d  is not particularly limited. For example, 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 may be included. 
       FIG.  9    is a view illustrating an operation of forming a  1   a  electrode layer by a transfer process.  FIG.  10    is a view illustrating an operation of forming a  1   b  electrode layer by a transfer process.  FIGS.  11  and  12    are views illustrating a process of forming a  1   c  electrode layer. 
     Referring to  FIGS.  9  to  12   , as illustrated in  FIG.  9   , in a case of a transfer process of a  1   a  electrode layer  131   a , a  1   a  electrode layer sheet  130   a  may be provided on a support  300 , and a body  110  may be pressed against the  1   a  electrode layer sheet  130   a  to adhere a  1   a  electrode layer  131   a  to a surface of the body  110 . The  1   a  electrode layer sheet  130   a  may be a state before sintering, and may contain components such as a binder, an organic solvent, or the like. 
     Thereafter, as illustrated in  FIG.  10   , in a case of a transfer process of a  1   b  electrode layer  131   b , a  1   b  electrode layer sheet  130   b  may be provided on a support  300 , and a body  110  may be pressed against the  1   b  electrode layer sheet  130   b  to adhere a  1   b  electrode layer  131   b  to a surface of a  1   a  electrode layer  131   a . The  1   b  electrode layer sheet  130   b  may be a state before sintering, and may contain components such as a binder, an organic solvent, or the like. 
     Thereafter, as illustrated in  FIG.  11   , a conductive paste  500  may be provided on a surface plate  400 , a body  110  may be dipped into the conductive paste  500  to form an electrode layer  130   c , and, then, as illustrated in  FIG.  12   , a portion of the electrode layer  130   c  may be removed using a porous material plate  600  to form a  1   c  electrode layer  131   c . 
     After forming the  1   c  electrode layer  131   c , the first external electrode  131  may be prepared by dipping the body on which the 1c electrode layer  131   c  is formed once again into the conductive paste, to form the first electrode layer  131   d . 
     Therefore, the  1   a  and  1   b  electrode layers  131   a  and  131   b  may be sintered electrodes formed by a transfer process, and the  1   c  and  1   d  electrode layers  131   c  and  131   d  may be sintered electrodes formed by a dipping process. 
     If a region of the first external electrode  131  disposed on the third surface  3  of the body is defined as a first connection portion A 1 , a region of the first external electrode  131  disposed on the first and second surfaces  1  and  2  of the body is defined as a first band portion B 1 , and a region between the first connection portion and the first band portion is defined as a first corner portion C 1 , a thickness (D 1 ) of the first corner portion may be 2.25 µm or more. 
     When the thickness (D 1 ) of the first corner portion is less than 2.25 µm, the external electrode or the plating layer may be disconnected, and a penetration path of a plating solution, moisture, or the like may be formed, to deteriorate reliability for moisture resistance. Therefore, the thickness (D 1 ) of the first corner portion may be 2.25 µm or more, and more preferably 2.3 µm or more. 
     An upper limit of the thickness D 1  of the first corner portion is not particularly limited, and may be determined according to thicknesses of the  1   a ,  1   b , and  1   c  electrode layers. 
     Further, when a thickness of the first corner portion is defined as D 1  and a thickness of the first connection portion in a central portion of the body  110  in the first direction is defined as D 2 , D 1 /D 2  may be 0.17 or more. 
     When D 1 /D 2  is less than 0.17, the external electrode or the plating layer may be disconnected, and a penetration path of a plating solution, moisture, or the like may be formed, to deteriorate reliability for moisture resistance. Further, even in a case that the thickness D 1  of the first corner portion is 2.25 µm or more, when D 1 /D 2  is less than 0.17, the external electrode may become too thick. Therefore, D 1 /D 2  may be 0.17 or more, and more preferably 0.19 or more. 
     If thicknesses of the  1   a  and  1   b  electrode layers  131   a  and  131   b  in a central portion of the body in the first direction (the Z direction) are defined as T a   1  and T b   1 , respectively, and thicknesses of the  1   a  and  1   b  electrode layers  131   a  and  131   b , at a point at which an internal electrode disposed at an outermost side in the first direction (the Z direction) is located, among the first and second internal electrodes  121  and  122 , are defined as T a   2  and T b   2 , respectively, T a   2 /T a   1  may be 0.9 to 1.1, and T b   2 /T b   1  may be 0.9 to 1.1. In this case, the thicknesses of the  1   a  and  1   b  electrode layers  131   a  and  131   b  may refer to distances of the  1   a  and  1   b  electrode layers  131   a  and  131   b  in the second direction (X direction). 
     The  1   a  and  1   b  electrode layers  131   a  and  131   b  may be formed by a transfer process, and thus may have a uniform thickness. 
     In addition, (T a   1  + T b   1 ) / (T a   2  + T b   2 ) may be 0.9 to 1.1, as both of the 1a and 1b electrode layers  131   a  and  131   b  are formed by a transfer process. 
     The sum of T a   2  and T b   2  may be 12 to 18 µm. 
     When the sum of T a   2  and T b   2  is less than 12 µm, a region in which a paste may be applied to a corner portion of the body may not be sufficiently secured. When the sum of T a   2  and T b   2  exceeds 18 µm, the external electrode may become too thick. 
     In addition, a thickness (Tc) of the  1   c  electrode layer may be 8 to 11 µm. In this case, the thickness (Tc) of the  1   c  electrode layer may refer to distances of the  1   c  electrode layer in the first direction (Z direction). 
     When the thickness (Tc) of the 1c electrode layer is less than 8 µm, a region in which a paste may be applied to a corner portion of the body may not be sufficiently secured. When the thickness (Tc) of the  1   c  electrode layer exceeds 11 µm, the external electrode may become too thick. 
     D 1 , D 2 , Tc, T a   1 , T a   2 , T b   1 , and T b   2  may be measured by scanning an image of a cross-section in the third and first directions (an L-T cross-section) of the body  110 , cut in a central portion of the body  110  in the width direction, scanned by a scanning electron microscope (SEM). D 1  may be from the edge of the body where the third and first surfaces meet to the outer surface of the layer  131   d . The direction to define D 1  is perpendicular to the tangent of the outer surface of the layer  131   d . D 2  may be from center in the first direction of the third surface to the outer surface of the layer  131   d . Tc may refer to maximum distances of the 1c electrode layer from first surface in the first direction (Z direction). 
     The first external electrode  131  may further include a plating layer  131   e  disposed on a portion of the  1   c  electrode layer  131   c  that is not covered by the  1   d  electrode layer  131   d , and disposed on the  1   d  electrode layer  131   d . Similarly, the second external electrode  132  may further include a plating layer  132   e  disposed on a portion of the  1   c  electrode layer  132   c  that is not covered by the  2   d  electrode layer  132   d , and disposed on the  1   d  electrode layer  132   d . 
     Since the  1   d  electrode layer  131   d  may be disposed to cover the portion of the  1   c  electrode layer  131   c , the plating layer  131   e  of the first external electrode may be disposed on a portion of the  1   d  electrode layer  131   d  or a portion of the  1   c  electrode layer  131   c , not covered by the  1   d  electrode layer  131   d , among the  1   d  electrode layer  131   d  and the  1   c  electrode layer  131   c . 
     The plating layers  131   e  and  132   e  may be a plating layer including one or more of nickel (Ni), tin (Sn), palladium (Pd), and alloys thereof, and may be formed as a plurality of layers. 
     For more specific examples of the plating layers  131   e  and  132   e , the plating layers  131   e  and  132   e  may be nickel (Ni) plating layers, or tin (Sn) plating layers, may have a form in which the nickel (Ni) plating layers and the tin (Sn) plating layers are sequentially formed, and may have a form in which the tin (Sn) plating layer, the nickel (Ni) plating layer, and the tin (Sn) plating layer are formed sequentially. In addition, the plating layers  131   e  and  132   e  may include a plurality of nickel (Ni) plating layers and/or a plurality of tin (Sn) plating layers. 
     Example 
     Table 1 below described a thickness (D 1 ) of a first corner portion, a thickness (D 2 ) of a first connection portion in a central portion of a body in a first direction, and a D 1 /D 2  value, relating to Inventive Examples, and, as illustrated in  FIG.  5   , fifteen (15) sample chips (Test Nos. 1 to 15) were prepared by disposing the 1a electrode layer  131   a  and the  1   b  electrode layer  131   b  on the first connection portion A 1 , disposing the  1   c  electrode layer  131   c  on the first band portion B 1 , and forming the  1   d  electrode layer  131   d , and D 1  and D 2  of the sample chips were measured and listed in Table 1. 
     Table 2 below described a thickness (D 1 ′ ) of a first corner portion, a thickness (D 2 ′ ) of a first connection portion in a central portion of a body in a first direction, and a D 1 ′ /D 2 ′ value, relating to Comparative Examples, and, as illustrated in  FIG.  6   , fifteen (15) sample chips (Test Nos. 16 to 30) were prepared by disposing the  1   a  electrode layer  131   a , not the  1   b  electrode layer  131   b , on the first connection portion A 1 , disposing the  1   c  electrode layer  131   c ′ on the first band portion B 1 , and forming the  1   d  electrode layer  131   d ′, and D 1 ′ and D 2 ′ of the sample chips were measured and listed in Table 2. 
     In addition, after a Ni plating operation was performed on the sample chips of Test Nos. 1 to 30, it was confirmed whether disconnection in Ni plating occurred, and the results thereof were illustrated in Tables 1 and 2 below.  
     
       
         
          TABLE 1
           
               
               
               
               
               
             
               
                 Test No. 
                 D2 (µm) 
                 D1 (µm) 
                 D1/D2 
                 Disconnection in Plating 
               
             
            
               
                 1 
                 11.24 
                 2.38 
                 0.21 
                 X 
               
               
                 2 
                 10.77 
                 2.65 
                 0.25 
                 X 
               
               
                 3 
                 11.49 
                 2.31 
                 0.20 
                 X 
               
               
                 4 
                 11.11 
                 3.49 
                 0.31 
                 X 
               
               
                 5 
                 11.97 
                 2.31 
                 0.19 
                 X 
               
               
                 6 
                 10.99 
                 3.99 
                 0.36 
                 X 
               
               
                 7 
                 11.77 
                 2.32 
                 0.20 
                 X 
               
               
                 8 
                 12.23 
                 2.37 
                 0.19 
                 X 
               
               
                 9 
                 12.46 
                 2.33 
                 0.19 
                 X 
               
               
                 10 
                 12.06 
                 2.47 
                 0.20 
                 X 
               
               
                 11 
                 13.96 
                 3.43 
                 0.25 
                 X 
               
               
                 12 
                 12.72 
                 2.55 
                 0.20 
                 X 
               
               
                 13 
                 12.01 
                 2.3 
                 0.19 
                 X 
               
               
                 14 
                 11.33 
                 4.32 
                 0.38 
                 X 
               
               
                 15 
                 11.83 
                 2.45 
                 0.21 
                 X 
               
            
           
         
       
     
     
       
         
          TABLE 2
           
               
               
               
               
               
             
               
                 Test No. 
                 D2′ (µm) 
                 D1′ (µm) 
                 D1′ /D2′ 
                 Disconnection in Plating 
               
             
            
               
                 16 
                 15.34 
                 2.07 
                 0.13 
                 O 
               
               
                 17 
                 13.98 
                 1.38 
                 0.10 
                 O 
               
               
                 18 
                 16.45 
                 2 
                 0.12 
                 O 
               
               
                 19 
                 15.96 
                 2.08 
                 0.13 
                 O 
               
               
                 20 
                 16.08 
                 1.98 
                 0.12 
                 O 
               
               
                 21 
                 14.32 
                 1.68 
                 0.12 
                 O 
               
               
                 22 
                 13.24 
                 1.04 
                 0.08 
                 O 
               
               
                 23 
                 13.08 
                 1.57 
                 0.12 
                 O 
               
               
                 24 
                 13.54 
                 1.57 
                 0.12 
                 O 
               
               
                 25 
                 14.98 
                 2.17 
                 0.14 
                 O 
               
               
                 26 
                 15.22 
                 1.47 
                 0.10 
                 O 
               
               
                 27 
                 15.32 
                 2.23 
                 0.15 
                 O 
               
               
                 28 
                 15.87 
                 1.41 
                 0.09 
                 O 
               
               
                 29 
                 17.57 
                 1.25 
                 0.07 
                 O 
               
               
                 30 
                 15.64 
                 1.67 
                 0.11 
                 O 
               
            
           
         
       
     
     As can be seen from Table 1 and Table 2, in the case of Comparative Examples, disconnection in plating occurred. In addition, in the case of Comparative Examples, it was difficult to secure the thickness (D 1 ′) of the first corner portion to 2.25 µm or more, and it was confirmed that D 1 ′/D 2 ′ was also less than 0.17. 
     In the case of Inventive Examples, it was confirmed that no disconnection in plating occurred in Test Nos. 1 to 15, and D1 was also secured at 2.25 µm or more, and D1/D2 was 0.17 or more. 
     One of the various effects of the present disclosure is to secure a thickness of a corner portion of an external electrode, to improve reliability for moisture resistance of the multilayer electronic component. 
     One of the various effects of the present disclosure is that a thickness of a connection portion may be made thinner than in the prior art, to improve capacitance per unit volume of the multilayer electronic component. 
     However, various advantages and effects of the present disclosure are not limited to the above, and may be more easily understood in the process of describing the specific embodiment of the present disclosure. 
     While example embodiments have been illustrated and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present disclosure as defined by the appended claims.