The present disclosure relates to a coil component.
An inductor, one of the coil components, is a typical passive electronic component used in electronic devices along with a resistor and a capacitor.
As electronic devices have increasingly high performance and are made compact, electronic components used in electronic devices increase in number and are miniaturized.
In the case of a thin film type coil component, a magnetic composite sheet in which magnetic metal powder particles are dispersed in an insulating resin is laminated and cured on a substrate on which a coil unit is formed by plating to form a body, and external electrodes are formed on a surface of the body.
Meanwhile, among coil components is provided a vertical coil component in which a coil in the component is disposed perpendicularly to a mounting surface of the component in order to minimize a mounting area of the coil component on a mounting board such as a printed circuit board (PCB) or the like.
An aspect of the present disclosure may provide a coil component in which connection reliability between a coil unit and external electrodes is improved.
According to an aspect of the present disclosure, a coil component includes: a body having a first surface and including first and second recessed-cutout portions spaced apart from each other on the first surface of the body; a support substrate disposed in the body; a coil unit disposed on the support substrate and disposed to be perpendicularly to the first surface of the body; and first and second external electrodes disposed to be spaced apart from each other on the first surface of the body and connected to first and second lead patterns of the coil unit, respectively, wherein the first and second external electrodes include conductive resin layers respectively filling the first and second recessed-cutout portions to be in contact with the first and second lead patterns exposed to the first and second recessed-cutout portions, each of the conductive resin layers having a first surface exposed to the first surface of the body, and the first and second external electrodes further include electrode layers disposed on the first surfaces of the conductive resin layers.
According to another aspect of the present disclosure, a coil component includes: a body having a first surface and including first and second recessed-cutout portions spaced apart from each other on the first surface of the body; a coil unit disposed in the body and perpendicularly to the first surface of the body and including first and second lead patterns exposed to inner surfaces of the first and second recessed-cutout portions, respectively; and first and second external electrodes spaced apart from each other on the first surface of the body and connected to the first and second lead patterns, respectively, wherein the first and second external electrodes each includes a conductive resin layer including a base resin and a conductive connection portion disposed in the base resin and connected to the first and second lead patterns respectively exposed to the first and second recessed-cutout portions.
According to still another aspect of the present disclosure, a coil component includes: a body: a coil unit disposed in the body and perpendicularly to a first surface of the body and including first and second lead patterns; first and second external electrodes, at least partially embedded in the body, spaced apart from each other on the first surface of the body, wherein each of the first and second external electrodes includes a conductive resin layer, partially embedded in the body to be connected to the first or second lead pattern, and an electrode layer disposed on a first surface of the conductive resin layer exposed to the first surface of the body.
The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.
Various types of electronic components are used in electronic devices, and various types of coil components may be appropriately used between the electronic components for the purpose of removing noise.
That is, in an electronic device, a coil component may be used as a power inductor, a high frequency (HF) inductor, a general bead, a high frequency bead (GHz bead), a common mode filter, and the like.
Referring to
The body 100 forms the exterior of the coil component 1000 according to this exemplary embodiment, and the coil unit 300 is embedded in the body 100.
The body 100 may be formed in the shape of a hexahedron as a whole.
In
By way of example, the body 100 may be formed such that the coil component 1000 according to the present exemplary embodiment including external electrodes 400 and 500 and the surface insulating layer 600 to be described later has a length of 1.0 mm, a width of 0.5 mm, and a thickness of 0.8 mm or has a length of 0.8 mm, a width of 0.4 mm, and a thickness of 0.8 mm but is not limited thereto. Meanwhile, the aforementioned dimensions are merely design values that do not reflect process errors, etc., and thus, it should be appreciated that dimensions within a range admitted as a process error fall within the scope of the present disclosure.
Based on an optical microscope or a scanning electron microscope (SEM) image for a length directional (L)-thickness directional (T) cross-section at a width-directional (W) central portion of the coil component 1000, the length of the coil component 1000 may refer to a maximum value among lengths of a plurality of segments parallel to the length direction L when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the length of the coil component 1000 may refer to a minimum value among lengths of a plurality of segments parallel to the length direction L when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the length of the coil component 1000 described above may refer to an arithmetic mean value of the lengths of at least two of the plurality of segments parallel to the length direction L when the outermost boundary lines of the coil component 1000 illustrated in the cross-sectional image are connected.
Based on the optical microscope or SEM image for the length directional (L)-thickness directional (T) cross-section at the width-directional (W) central portion of the coil component 1000, the thickness of the coil component 1000 may refer to a maximum value among lengths of a plurality of segments parallel to the thickness direction T when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the thickness of the coil component 1000 may refer to a minimum value among lengths of a plurality of segments parallel to the thickness direction T when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the thickness of the coil component 1000 described above may refer to an arithmetic mean value of the lengths of at least two of the plurality of segments parallel to the thickness direction T when the outermost boundary lines of the coil component 1000 illustrated in the cross-sectional image are connected.
Based on an optical microscope or SEM image for a length directional (L)-width directional (W) cross-section at a thickness-directional (T)-central portion of the coil component 1000, the width of the coil component 1000 may refer to a maximum value among lengths of a plurality of segments parallel to the width direction W when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the width of the coil component 1000 may refer to a minimum value among lengths of a plurality of segments parallel to the width direction W when outermost boundary lines of the coil component 1000 illustrated in the image of the cross-section are connected. Alternatively, the width of the coil component 1000 described above may refer to an arithmetic mean value of the lengths of at least two of the plurality of segments parallel to the width direction W when the outermost boundary lines of the coil component 1000 illustrated in the cross-sectional image are connected.
Alternatively, each of the length, width, and thickness of the coil component 1000 may be measured by a micrometer measurement method. With the micrometer measurement method, each of the length, width, and thickness of the coil component 1000 may be measured by setting a zero point with a gage repeatability and reproducibility (R&R) micrometer, inserting the coil component 1000 according to the present exemplary embodiment into a tip of the micrometer, and turning a measurement lever of the micrometer. In measuring the length of the coil component 1000 by the micrometer measurement method, the length of the coil component 1000 may refer to a value measured once or an arithmetic mean of values measured multiple times. This may equally be applied to the width and thickness of the coil component 1000.
The body 100 may include an insulating resin and a magnetic material. Specifically, the body 100 may be formed by laminating one or more magnetic composite sheets in which a magnetic material is dispersed in an insulating resin. The magnetic material may be ferrite or magnetic metal powder particles.
Ferrite may be at least one of, for example, spinel type ferrite such as Mg—Zn-based ferrite, Mn—Zn-based ferrite, Mn—Mg-based ferrite, Cu—Zn-based ferrite, Mg—Mn—Sr-based ferrite, or Ni—Zn-based ferrite, hexagonal ferrites such as Ba—Zn-based ferrite, Ba—Mg-based ferrite, Ba—Ni-based ferrite, Ba—Co-based ferrite, or Ba—Ni—Co-based ferrite, garnet type ferrite such as Y-based ferrite, and Li-based ferrite.
Magnetic metal powder particles may include at least any one selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), cobalt (Co), molybdenum (Mo), aluminum (Al), niobium (Nb), copper (Cu) and nickel (Ni). For example, the magnetic metal powder particles may be at least one of pure iron powder particles, Fe—Si-based alloy powder particles, Fe—Si—Al-based alloy powder particles, Fe—Ni-based alloy powder particles, Fe—Ni—Mo-based alloy powder particles, Fe—Ni—Mo—Cu-based alloy powder particles, Fe—Co-based alloy powder particles, Fe—Ni—Co-based alloy powder particles, Fe—Cr-based alloy powder particles, Fe—Cr—Si alloy powder particles, Fe—Si—Cu—Nb-based alloy powder particles, Fe—Ni—Cr-based alloy powder particles, and Fe—Cr—Al-based alloy powder particles.
The magnetic metal powder particles may be amorphous or crystalline. For example, the magnetic metal powder particles may be Fe—Si—B—Cr-based amorphous alloy powder particles, but is not limited thereto.
Ferrite and the magnetic metal powder particles may have an average diameter of about 0.1 μm to 30 μm, but is not limited thereto.
The body 100 may include two or more types of magnetic materials dispersed in a resin. Here, the different types of magnetic materials refer to that magnetic materials dispersed in a resin are distinguished from each other by any one of an average diameter, a composition, crystallinity, and a shape.
Meanwhile, hereinafter, it is assumed that the magnetic material is magnetic metal powder particles, but the scope of the present disclosure is not limited only to the body 100 having a structure in which the magnetic metal powder particles are dispersed in the insulating resin.
The insulating resin may include, but is not limited to, epoxy, polyimide, liquid crystal polymer, or the like alone or in combination.
The body 100 includes a core 110 penetrating a central portion of each of the support substrate 200 and the coil unit 300 to be described later. The core 110 may be formed by filling a through hole penetrating the central portion of each of the coil unit 300 and the support substrate 200 by the magnetic composite sheet, but is not limited thereto.
The support substrate 200 is disposed in the body 100. The support substrate 200 is configured to support the coil unit 300 to be described later.
The support substrate 200 may be formed of an insulating material including a thermosetting insulating resin such as an epoxy resin, a thermoplastic insulating resin such as polyimide, or a photosensitive insulating resin or may be formed of an insulating material prepared by impregnating a reinforcing material such as glass fiber or inorganic filler in this insulating resin. As an example, the support substrate 200 may be formed of insulating materials such as prepreg, Ajinomoto build-up film (ABF), FR-4, a bismaleimide triazine (BT) resin, photo imageable dielectric (PID), a copper clad laminate (CCL) etc., but is not limited thereto.
As an inorganic filler, at least one selected from the group consisting of silica (SiO2), alumina (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc, mud, mica powder particles, aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), magnesium carbonate (MgCO3), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO3), barium titanate (BaTiO3) and calcium zirconate (CaZrO3) may be used.
When the support substrate 200 is formed of an insulating material including a reinforcing material, the support substrate 200 may provide more excellent rigidity. If the support substrate 200 is formed of an insulating material that does not contain glass fibers, the support substrate 200 is advantageous in reducing the width of the component by reducing the thickness of the entirety of the coil unit 300 (which refers to the sum of lengths of the coil unit and the support substrate according to the width direction W of
The coil unit 300 is disposed on the support substrate 200. The coil unit 300 is embedded in the body 100 and manifests the characteristics of the coil component 1000. For example, when the coil component 1000 of the present exemplary embodiment is used as a power inductor, the coil unit 300 may serve to stabilize power of an electronic device by storing an electric field as a magnetic field and maintaining an output voltage.
The coil unit 300 is disposed on the support substrate 200 perpendicularly to the sixth surface 106 of the body 100. The coil unit 300 is formed on at least one of both surfaces of the support substrate 200 facing each other in the width direction W, and forms at least one turn. The coil unit 300 is disposed on one surface and the other surface of the support substrate 200 facing each other in the width direction W of the body 100 and is disposed to be perpendicularly to the sixth surface 106 of the body 100. In this exemplary embodiment, the coil unit 300 includes coil patterns 311 and 312, vias 320, and lead patterns 331 and 332.
Each of the first coil pattern 311 and the second coil pattern 312 may be in the form of a flat spiral in which at least one turn is formed around the core 110 of the body 100. For example, based on the direction of
Based on the direction of
At least one of the coil patterns 311 and 312, the via 320, and the lead patterns 331 and 332 may include at least one conductive layer.
As an example, when the first coil pattern 311, the via 320, and the first lead pattern 331 are formed by plating on the front surface of the support substrate 200 (based on the direction of
Each of the coil patterns 311 and 312, the via 320, and the lead patterns 331 and 332 may include a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), chromium (Cr), molybdenum (Mo), or an alloy thereof, but is not limited thereto.
In the case of this exemplary embodiment, since the coil unit 300 is disposed perpendicularly to the sixth surface 106 of the body 100, which is a mounting surface, a mounting area may be reduced, while the volume of the body 100 and the coil unit 300 is maintained. Therefore, a larger number of electronic components may be mounted on a mounting board having the same area. In addition, in the case of the present exemplary embodiment, since the coil unit 300 is disposed perpendicularly to the sixth surface 106 of the body 100 as the mounting surface, a direction of a magnetic flux induced to the core 110 by the coil unit 300 is parallel to the sixth surface 106 of the body 100. As a result, noise induced to the mounting surface of the mounting board may be relatively reduced. Meanwhile, in the present disclosure, that the coil unit 300 is disposed perpendicularly to the sixth surface 106 of the body 100 means that a central axis of the core 110 disposed at the central portion of the coil unit 300 and the sixth surface 106 of the body 100 form an angle in the range of approximately 160° to 200°.
The recessed-cutout portions S1 and S2 are formed to be spaced apart from each other in the length direction L on the sixth surface 106 of the body 100 and allow the first and second lead patterns 331 and 332 to be exposed to inner surfaces thereof. Specifically, the first recessed-cutout portion S1 is formed on the sixth surface 106 of the body 100 and allows the first lead pattern 331 to be exposed to the inner surface thereof. The second recessed-cutout portion S2 is formed to be spaced apart from the first recessed-cutout portion S1 on the sixth surface 106 of the body 100 and allows the second lead pattern 332 to be exposed to the inner surface thereof. The recessed-cutout portions S1 and S2 may be formed by dicing a coil bar in which a plurality of bodies are connected to individualize bodies of a plurality of components and performing slit dicing or wire sawing on the six surface 106 of the body 100. The recessed-cutout portions S1 and S2 may be formed in the body 100 before a process of forming the external electrodes 400 and 500, which will be described later, so that conductive resin layers 410 and 510 of the external electrodes 400 and 500 to be described later may be disposed in the recessed-cutout portions S1 and S2.
The recessed-cutout portions S1 and S2 may extend to corner portions between each of the third and fourth surfaces 103 and 104 of the body 100 and the sixth surface 106 of the body 100 on the six surface 106 of the body 100. Also, the recessed-cutout portions S1 and S2 may extend to corner portions between each of the first and second surfaces 101 and 102 of the body 100 and the sixth surface 106 of the body 100 on the six surface 106 of the body 100. Specifically, on the sixth surface 106 of the body 100, the first recessed-cutout portion S1 may extend from the corner portion between the sixth surface 106 of the body 100 and the third surface 103 of the body 100 to the corner portion between the sixth surface 106 of the body 100 and the fourth surface 104 of the body 100 and extend to the corner portion between the sixth surface 106 of the body 100 and the first surface 101 of the body 100. On the sixth surface 106 of the body 100, the second recessed-cutout portion S2 extends from the corner portion between the sixth surface 106 of the body 100 and the third surface 103 of the body 100 to the corner portion between the sixth surface 106 of the body 100 and the fourth surface 104 of the body 100. That is, each of the recessed-cutout portions S1 and S2 is formed on the entirety of the body 100 in the width direction W on the sixth surface 106 of the body 100. Also, one of both ends of each of the recessed-cutout portions S1 and S2 facing each other in the length direction L extends to the first and second surfaces 101 and 102 of the body 100 facing each other in the length direction L. The recessed-cutout portions S1 and S2 are filled with conductive resin layers 410 and 510 of the external electrodes 400 and 500 to be described later, and since each of the recessed-cutout portions S1 and S2 extends to three out of four surfaces connected to the sixth surface 106 of the body 100 on the sixth surface 106 of the body 100, a volume of the recessed-cutout portions S1 and S2 that may be filled with the conductive resin layers 410 and 510 may increase. The conductive resin layers 410 and 510 include base resins 411 and 511 to be described later, and since the base resins 411 and 511 are the same polymeric material as the insulating resin included in the body 100, a contact area between the body 100 and the conductive layers 410 and 510 including the homogeneous material may increase, and thus bonding force therebetween may increase. Furthermore, bonding force between the external electrodes 400 and 500 and the body 100 increases.
The external electrodes 400 and 500 are disposed spaced apart from each other on the sixth surface 106 of the body and are connected to the first and second lead patterns 331 and 332 of the coil unit 300, respectively. The external electrodes 400 and 500 include the conductive resin layers 410 and 510 filling the recessed-cutout portions S1 and S2 to be in contact with the lead patterns 331 and 332 exposed to the recessed-cutout portions S1 and S2 and having one surface exposed to the sixth surface 106 of the body 100 and electrode layers 420 and 520 disposed on one surface of the conductive resin layers 410 and 510. Specifically, the first external electrode 400 includes the first conductive resin layer 410 filling the first recessed-cutout portion S1 to be in contact with the first lead pattern 331 exposed to the first recessed-cutout portion S1 and having one surface exposed to the sixth surface 106 of the body 100 and the first electrode layer 420 disposed on one surface of the first conductive resin layer 410. The second external electrode 500 includes the second conductive resin layer 510 filling the second recessed-cutout portion S2 to be in contact with the second lead pattern 332 exposed to the second recessed-cutout portion S2 and having one surface exposed to the sixth surface 106 of the body 100 and the second electrode layer 520 disposed on one surface of the second conductive resin layer 510.
The external electrodes 400 and 500 electrically connect the coil component 1000 according to the present exemplary embodiment to a printed circuit board (PCB) or the like when the coil component 1000 is mounted on the PCB or the like. As an example, the coil component 1000 according to the present exemplary embodiment may be mounted so that the sixth surface 106 of the body 100 faces an upper surface of the PCB, and the external electrodes 400 and 500 spaced apart from each other on the sixth surface of the body 100 and a connection portion of the PCB may be electrically connected to each other.
The external electrodes 400 and 500 may be formed of copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or an alloy thereof, but are not limited thereto.
An intermetallic compound (IMC) is disposed on the exposed surfaces of each of the first and second lead patterns 331 and 332 exposed to the first and second recessed-cutout portions S1 and S2 and is in contact with the conductive connection portion 412. Meanwhile, in the following description of the external electrodes 400 and 500 and the intermetallic compound (IMC), the first external electrode 400 is mainly described, but the description of the first external electrode 400 may also be applied to the second external electrode 500 equally.
The first conductive resin layer 410 includes the base resin 411 and the conductive connection portion 412 disposed in the base resin 411 and connecting the first lead pattern 331 exposed to the first recessed-cutout portion S1 to the first electrode layer 420. The first conductive resin layer 410 may be formed by filling the first recessed-cutout portion S1 with a conductive paste in which a plurality of metal particles are dispersed in the base resin 411 and drying and curing the conductive paste. Meanwhile, the plurality of metal particles in the conductive paste may be at least partially melted and then cooled by heat and pressure during a drying and curing process, thereby forming the conductive connection portion 412 of the conductive resin layer 410. Specifically, the conductive paste may include metal powder particles containing a low melting point metal having a melting point lower than a curing temperature of the base resin 411 and metal powder particles containing a high melting point metal having a melting point higher than the melting point of the low melting point metal particles. When the paste is cured, the metal powder particles of the low melting point metal is melted and reacts with the metal powder particles of the high melting point metal to form the conductive connection portion 412. Meanwhile,
The conductive connection portion 412 may be formed as the metal powder particles including the low melting point metal described above is melted and then cooled in the process of drying and curing the conductive paste. Thus, the low melting point metal included in the conductive connection portion 412 may have a melting point lower than a curing temperature of the base resin 411. The low melting point metal included in the conductive connection portion 412 may preferably have a melting point of 300° C. or less.
The metal included in the conductive connection portion 412 may be formed of an alloy of two or more selected from tin (Sn), lead (Pb), indium (In), copper (Cu), silver (Ag), and bismuth (Bi). When the aforementioned conductive paste includes silver (Ag) and tin (Sn) powder particles, the conductive connection portion 412 may include Ag3Sn. In this case, the first lead pattern 331 may include copper (Cu), and the intermetallic compound (IMC) disposed between the conductive connection portion 412 and the first lead pattern 331 may include Cu—Sn.
The intermetallic compound (IMC) is disposed between the exposed surface of the first lead pattern 331 exposed to the first recessed-cutout portion S1 and the first conductive resin layer 410 and is in contact with and connected to the conductive connection portion 412. The intermetallic compound (IMC) improves electrical and mechanical bonding between the first conductive resin layer 410 and the first lead pattern 331 to reduce contact resistance between the first conductive resin layer 410 and the first lead pattern 331.
The intermetallic compound (IMC) may be formed by reacting a metal powder particles including the low melting point metal described above with a metal constituting the first lead pattern 331 during the process of drying and curing the paste. Specifically, when the metal powder particles containing the low melting point metal includes tin (Sn) and the first lead pattern 331 includes copper (Cu), the intermetallic compound (IMC) may include copper-tin (Cu—Sn). However, this is only an example and the intermetallic compound (IMC) may be formed of one of silver-tin (Ag—Sn) and nickel-tin (Ni—Sn).
A plurality of IMCs may be arranged between the first conductive resin layer 410 and the exposed surface of the first lead pattern 331 and spaced apart from each other. That is, the IMCs may be arranged in the form of a plurality of islands spaced apart from each other on the exposed surface of the first lead pattern 331, and each of the plurality of IMCs and the conductive connection portion 412 of the first conductive resin layer 410 may be in contact with each other.
The base resin 411 may include a thermosetting resin having electrical insulation properties. The thermosetting resin may be, for example, an epoxy resin, and the present disclosure is not limited thereto. The thermosetting resin included in the base resin 411 may be the same as the thermosetting resin included in the body 100. In this case, a mechanical bonding force between the first conductive resin layer 410 and the body 100 may be improved.
The first electrode layer 420 may include at least one plating layer. That is, each of the external electrodes 400 and 500 may be formed in a multilayer structure. Specifically, the first external electrode 400 may include a first sub-layer in contact with the first conductive resin layer and including nickel (Ni) and a second sub-layer disposed on the first sub-layer and including tin (Sn), as the first electrode layer 420. The first electrode layer 420 may be an electroplating layer formed with the first conductive resin layer 410 as a seed layer, but the scope of the present disclosure is not limited thereto.
The surface insulating layer 600 is disposed in a region of the sixth surface 106 of the body 100, excluding a region in which the external electrodes 400 and 500 are formed. The surface insulating layer 600 is also disposed on at least a part of each of the first to fifth surfaces 101, 102, 103, 104 and 105 of the body 100. In this exemplary embodiment, the surface insulating layer 600 is disposed to cover each of the first to fifth surfaces 101, 102, 103, 104 and 105 of the body 100 and is disposed in the region of the sixth surface 106 of the body 100 described above.
The surface insulating layer 600, for example, may be formed by applying and curing an insulating material including an insulating resin on the body 100, may be formed by laminating and curing an insulating film including an insulating resin, or may be formed by spray-coating a liquid insulating material including an insulating resin. In this case, the surface insulating layer 600 may include at least one of a thermoplastic resin such as polystyrene, vinyl acetate, polyester, polyethylene, polypropylene, polyamide, rubber, acryl-based resin, a thermosetting resin such as phenol, epoxy, urethane, melamine, and alkyd-based resin, and a photosensitive insulating resin. As another example, the surface insulating layer 600 may be formed by forming an insulating material on the body 100 by vapor deposition such as chemical vapor deposition (CVD).
The coil component 1000 according to the present exemplary embodiment may further include an insulating film IF formed on the surface of the support substrate 200 and the coil unit 300. The insulating film IF, which serves to insulate the coil unit 300 from the body 100, may include a known insulating material such as parylene, but is not limited thereto. The insulating film IF may be formed by a method such as vapor deposition, but is not limited thereto, and may be formed by laminating an insulating film on both surfaces of the support substrate 200.
In the coil component 1000 according to the present exemplary embodiment, since the conductive resin layers 410 and 420 having relatively excellent bonding strength with the body 100 are disposed in the recessed-cutout portions S1 and S2 formed on the body 100, a bonding force between the body 100 and the conductive resin layers 410 and 420 is improved. Accordingly, the bonding force between the body 100 and the coil unit 300 and the bonding force between the coil unit 300 and the external electrodes 400 and 500 are also improved.
Meanwhile,
When comparing
Referring to
Referring to
As set forth above, according to exemplary embodiments of the present disclosure, connection reliability between the coil unit and the external electrodes may be improved.
While exemplary embodiments have been shown 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.
Number | Date | Country | Kind |
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10-2020-0187196 | Dec 2020 | KR | national |
The present application is a continuation patent application of U.S. patent application Ser. No. 17/215,860, filed on Mar. 29, 2021, which claims the benefit of priority to Korean Patent Application No. 10-2020-0187196, filed on Dec. 30, 2020, the disclosures of which is incorporated herein by reference in their entireties.
Number | Date | Country | |
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Parent | 17215860 | Mar 2021 | US |
Child | 18416421 | US |