Coil assembly

Abstract

A coil assembly is provided. The coil assembly includes a main body having a first surface and a second surface opposite to each other and a plurality of wall surfaces connecting the first surface to the second surface, and including an insulating resin and magnetic metal powder particles; an insulating substrate disposed in the main body; a coil portion disposed on the insulating substrate and including a lead-out pattern exposed to a first wall surface among the plurality of wall surfaces of the main body; and an external electrode disposed on the main body and connected to the lead-out pattern. Some of the magnetic metal particles are exposed to each of the plurality of wall surfaces of the main body. The magnetic metal particles exposed to the first wall surface of the main body have a cut surface. The magnetic metal particles exposed to a second wall surface among the plurality of wall surfaces of the main body, which is connected to the first wall surface, do not have a cut surface.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0171058, filed on December 9, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a coil assembly. Background Technology

[0003] An inductor (a type of coil assembly) is a typical passive electronic component used in electronic devices along with resistors and capacitors.

[0004] In the case of thin-film coil assemblies (where coils can be formed on a support substrate by electroplating), the bodies of multiple individual components and coils (also called coil strips) can be formed together on a large-area substrate, and the bodies of the multiple individual components that are connected to each other can be separated by a cutting process. Subsequently, external electrodes and surface insulating layers can be formed on the body of the assembly.

[0005] Because multiple individual components can form rows and columns in the coil strip in each of the length and width directions, a conventional cutting process may require cutting both in the length and width directions. However, due to the double cutting, the alignment between the cutting line and the cutting saw may become misaligned, potentially increasing defects. Summary of the Invention

[0006] One aspect of this disclosure is to provide a coil assembly that eliminates the need for a cutting process in either the length direction L or the width direction W of the assembly.

[0007] According to one aspect of this disclosure, a coil assembly includes: a body having a first surface and a second surface opposite to each other and a plurality of wall surfaces connecting the first surface to the second surface, and comprising an insulating resin and magnetic metal particles; an insulating substrate disposed in the body; a coil portion disposed on the insulating substrate and including a lead pattern exposed on the first wall surface of the plurality of wall surfaces of the body; and an external electrode disposed on the body and connected to the lead pattern. Some of the magnetic metal particles are exposed on each of the plurality of wall surfaces of the body. The magnetic metal particles exposed on the first wall surface of the body have a cut surface. The magnetic metal particles exposed on the second wall surface of the plurality of wall surfaces of the body do not have a cut surface, and the second wall surface is connected to the first wall surface.

[0008] According to another aspect of this disclosure, a coil assembly includes: a body having a first surface and a second surface opposite to each other and a plurality of wall surfaces connecting the first surface to the second surface, and comprising an insulating resin and magnetic metal particles; an insulating substrate disposed in the body; a coil portion disposed on the insulating substrate and including a lead pattern exposed to the first wall surface of the plurality of wall surfaces of the body; and an external electrode disposed on the body and connected to the lead pattern. Some of the magnetic metal particles are exposed to each of the plurality of wall surfaces of the body. The exposed portions of the magnetic metal particles exposed to the first wall surface of the body have substantially flat surfaces. The exposed portions of the magnetic metal particles exposed to the second wall surface of the body do not have substantially flat surfaces, and the second wall surface of the body is connected to the first wall surface of the body among the plurality of wall surfaces of the body.

[0009] According to another aspect of this disclosure, a coil assembly includes: a body comprising an insulating resin and magnetic metal particles; an insulating substrate disposed in the body; a coil portion disposed on the insulating substrate and including a lead-out pattern exposed from the body; and an external electrode disposed on the body and connected to the lead-out pattern. Some of the magnetic metal particles are exposed on each of the outer surfaces of the body. Of all the magnetic metal particles included in the body, only the magnetic metal particles exposed on a first surface of the body have a cut-out surface, and the lead-out pattern is exposed on the first surface of the body. Attached Figure Description

[0010] The above and other aspects, features and advantages of this disclosure will be more clearly understood by taking into account the accompanying drawings and the following detailed description, in which:

[0011] Figure 1 This is a perspective view showing a coil assembly according to an exemplary embodiment of the present disclosure;

[0012] Figure 2 It is along Figure 1 A cross-sectional view taken from line I-I' in the diagram;

[0013] Figure 3 It is shown Figure 2 Enlarged views of parts A and A' in the image;

[0014] Figure 4 It is shown Figure 2 Enlarged views of parts B and B' in the image;

[0015] Figure 5 It is along Figure 1 A cross-sectional view taken from line II-II' in the diagram;

[0016] Figure 6 It is shown Figure 5 Enlarged views of parts C and C' in the diagram;

[0017] Figure 7 This is a perspective view showing a coil assembly according to another exemplary embodiment of the present disclosure;

[0018] Figure 8 It is along Figure 7 A cross-sectional view taken from line III-III' in the diagram;

[0019] Figure 9 It is shown Figure 8 Enlarged views of parts D and D' in the diagram;

[0020] Figure 10 It is shown Figure 8 Enlarged views of parts E and E' in the diagram;

[0021] Figure 11 It is along Figure 7 The cross-sectional view taken by line IV-IV' in the middle; and

[0022] Figure 12 It is shown Figure 11 A magnified view of part F in the image. Detailed Implementation

[0023] The terminology used in the exemplary embodiments is for the purpose of simply describing the exemplary embodiments and is not intended to limit this disclosure. Unless otherwise stated, singular terms include plural forms. Terms such as “comprising,” “including,” “constructed as,” etc., are used to indicate the presence of features, quantities, steps, operations, elements, parts, or combinations thereof, and do not exclude the possibility of combining or adding one or more features, quantities, steps, operations, elements, parts, or combinations thereof. Furthermore, terms such as “set on,” “positioned on,” etc., may indicate that an element is positioned on or below an object, and do not necessarily mean that the element is positioned on the object relative to the direction of gravity.

[0024] The terms “integrated into” and “combined into” can not only indicate that elements are in direct and physical contact with each other, but can also include a configuration in which another element is located between the elements such that the elements are also in contact with the other element.

[0025] The dimensions and thicknesses of the elements shown in the accompanying drawings are illustrated as examples for the purpose of description, and the exemplary embodiments in this disclosure are not limited thereto.

[0026] In the attached figures, the L direction is the first direction or length direction, the W direction is the second direction or width direction, and the T direction is the third direction or thickness direction.

[0027] In the description provided with reference to the accompanying drawings, the same reference numerals will be used to describe the same elements or corresponding elements, and repeated descriptions will not be repeated.

[0028] In electronic devices, various types of electronic components can be used, and various types of coil assemblies can be used between electronic components to remove noise or for other purposes.

[0029] In other words, in electronic devices, coil assemblies can be used as power inductors, high-frequency inductors, ordinary ferrite beads, high-frequency ferrite beads, common-mode filters, etc.

[0030] Figure 1 This is a perspective view showing a coil assembly according to an example embodiment. Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I' in the diagram. Figure 3 It is shown Figure 2 Enlarged views of parts A and A' in the image. Figure 4 It is shown Figure 2 Enlarged views of parts B and B' in the image. Figure 5 It is along Figure 1 The cross-sectional view taken from line II-II' in the diagram. Figure 6 It is shown Figure 5 Enlarged views of parts C and C' in the diagram.

[0031] Reference Figures 1 to 6 The coil assembly 1000 in the example embodiment may include a body 100, a support substrate 200, a coil portion 300, external electrodes 410 and 420, and a surface insulating layer 500, and may also include an insulating layer IF.

[0032] In an example embodiment, the body 100 may form the appearance of the coil assembly 1000, and the support substrate 200 and the coil portion 300 may be disposed in the body 100.

[0033] The main body 100 may have a hexahedral shape.

[0034] Reference Figures 1 to 5As shown in the diagram, the body 100 may include a first surface 101 and a second surface 102 opposite to each other in the length direction L, a third surface 103 and a fourth surface 104 opposite to each other in the width direction W, and a fifth surface 105 and a sixth surface 106 opposite to each other in the thickness direction T. The first surface 101, second surface 102, third surface 103, and fourth surface 104 of the body 100 may be wall surfaces of the body 100 that connect the fifth surface 105 of the body 100 to the sixth surface 106. In the following description, the two end surfaces (one end surface and the other end surface) of the body 100 may refer to the first surface 101 and the second surface 102 of the body 100, the two side surfaces (one side surface and the other side surface) of the body 100 may refer to the third surface 103 and the fourth surface 104 of the body 100, and one surface and the other surface of the body 100 may refer to the sixth surface 106 and the fifth surface 105 of the body 100, respectively.

[0035] The body 100 may be configured such that the coil assembly 1000, on which the outer electrodes 410 and 420 and the surface insulating layer 500 are formed, may have, for example, a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.65 mm, but exemplary embodiments thereof are not limited thereto. The dimensions described above are exemplary dimensions determined without taking into account manufacturing errors, and examples of dimensions are not limited thereto.

[0036] Based on an optical microscope or scanning electron microscope (SEM) image of a cross-section taken at the central portion of the width direction W of the coil assembly 1000 along the length direction L-thickness direction T, the length of the coil assembly 1000 can refer to the maximum value of the dimensions of a plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the length direction L and parallel to the length direction L. Alternatively, the length of the coil assembly 1000 can refer to the arithmetic mean of the dimensions of at least two of the plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the length direction L and parallel to the length direction L in the aforementioned image.

[0037] Based on an optical microscope or scanning electron microscope (SEM) image of a cross-section taken at the central portion of the width direction W of the coil assembly 1000 along the length direction L-thickness direction T, the thickness of the coil assembly 1000 may refer to the maximum value of the dimensions of a plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the thickness direction T and parallel to the thickness direction T. Alternatively, the thickness of the coil assembly 1000 may refer to the arithmetic mean of the dimensions of at least two of the plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the thickness direction T and parallel to the thickness direction T in the aforementioned image.

[0038] Based on an optical microscope or scanning electron microscope (SEM) image of a cross-section taken at the central portion of the coil assembly 1000 in the thickness direction T, the width of the coil assembly 1000 can refer to the maximum value of the dimensions of a plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the width direction W and parallel to the width direction W. Alternatively, the width of the coil assembly 1000 can refer to the arithmetic mean of the dimensions of at least two of the plurality of lines connecting the two outermost boundary lines of the coil assembly 1000 that are opposite each other in the width direction W and parallel to the width direction W in the aforementioned image.

[0039] Optionally, the length, width, and thickness of the coil assembly 1000 can be measured using a micrometer measurement method. In this method, a zero point can be set using a metrological repeatability and reproducibility (R&R) micrometer. The coil assembly 1000 of the example embodiment can be inserted between the tips of the micrometer, and the measurement can be performed by rotating the measuring rod of the micrometer. When measuring the length of the coil assembly 1000 using the micrometer measurement method, the length can refer to the value of a single measurement or the arithmetic mean of multiple measurements. This measurement method can also be applied to the width and thickness of the coil assembly 1000.

[0040] The body 100 may include magnetic metal particles 20 and 30 and insulating resin 10. Specifically, the body 100 may be formed by laminating one or more magnetic composite sheets comprising insulating resin 10 and magnetic metal particles 20 and 30 dispersed in the insulating resin 10.

[0041] Magnetic metal particles 20 and 30 may include one or more 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, magnetic metal particles 20 and 30 may be one or more selected from pure iron, Fe-Si alloy, Fe-Si-Al alloy, Fe-Ni alloy, Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Co alloy, Fe-Ni-Co alloy, Fe-Cr alloy, Fe-Cr-Si alloy, Fe-Si-Cu-Nb alloy, Fe-Ni-Cr alloy, and Fe-Cr-Al alloy.

[0042] The magnetic metal particles 20 and 30 can be amorphous or crystalline. For example, the magnetic metal particles 20 and 30 can be an Fe-Si-B-Cr amorphous alloy, but the exemplary embodiments of the magnetic metal particles are not limited thereto. Each of the magnetic metal particles 20 and 30 can have an average diameter of about 0.1 μm to 30 μm, but the exemplary embodiments thereto are not limited thereto.

[0043] Magnetic metal particles 20 and 30 may include a first magnetic metal particle 20 and a second magnetic metal particle 30 with a particle size smaller than that of the first magnetic metal particle 20. In an example embodiment, the term "particle size" or "average diameter" may refer to a particle size distribution represented by D90 or D50. In an example embodiment, since magnetic metal particles 20 and 30 may include a first magnetic metal particle 20 and a second magnetic metal particle 30 with a particle size smaller than that of the first magnetic metal particle 20, the second magnetic metal particle 30 may be disposed in the space between the first magnetic metal particles 20, thus increasing the proportion of magnetic material in the body 100 compared to a body 100 having the same volume. In the following description, for ease of description, the magnetic metal particles 20 and 30 of the body 100 may include a first magnetic metal particle 20 and a second magnetic metal particle 30 with different particle sizes, but the example embodiment is not limited thereto. As another example, the magnetic metal particles may include three types of magnetic metal particles with different particle sizes, but are not limited thereto.

[0044] Insulating coatings 22 and 32 may be formed on the surfaces of magnetic metal particles 20 and 30, respectively. Specifically, the first magnetic metal particle 20 may include a conductive first core particle 21 and a first insulating coating 22 covering the first core particle 21. The second magnetic metal particle 30 may include a conductive second core particle 31 and a second insulating coating 32 covering the second core particle 31. The insulating coatings 22 and 32 may be configured as oxide films, which may include one of epoxy resin, polyimide, liquid crystal polymer, or mixtures thereof, or may include silicon dioxide (SiO2) or aluminum oxide (Al2O3), or may include metal oxides that include the metal components of the core particles 21 and 31.

[0045] The insulating resin 10 may include one of epoxy resin, polyimide, liquid crystal polymer or mixtures thereof, but examples of resins are not limited thereto.

[0046] Magnetic metal particles 20 and 30 may be exposed on each of the plurality of wall surfaces 101, 102, 103, and 104 of the body 100. A first surface 20A of the magnetic metal particles 20 and 30 may be formed only on the magnetic metal particles 20 and 30 exposed on the wall surfaces 101 and 102 of the body 100, and may be substantially coplanar with the wall surfaces 101 and 102 of the body 100. In other words, the magnetic metal particles 20 and 30 exposed on the first surface 101 of the body 100 may have a first surface 20A substantially coplanar with the first surface 101 of the body 100. The magnetic metal particles 20 and 30 exposed on the second surface 102 of the body 100 may have a first surface 20A substantially coplanar with the second surface 102 of the body 100. The magnetic metal particles 20 and 30 exposed on each of the third surface 103 and the fourth surface 104 of the body 100 may not have a first surface 20A that is substantially coplanar with the third surface 103 and the fourth surface 104 of the body 100. Those skilled in the art will understand that the expression "substantially coplanar" means being in the same plane, taking into account process errors, positional deviations and / or measurement errors that may occur in the manufacturing process.

[0047] The lead-out patterns 331 and 332 of the coil portion 300 can be exposed on the first surface 101 and the second surface 102 of the body 100, respectively. The exposed surface of the first lead-out pattern 331 on the first surface 101 of the body 100 is substantially coplanar with the first surface 101 of the body 100. The exposed surface of the second lead-out pattern 332 on the second surface 102 of the body 100 is substantially coplanar with the second surface 102 of the body 100. Therefore, the first surface 101 of the body 100, the first surface 20A of the magnetic metal particles 20 and 30 exposed on the first surface 101 of the body 100, and the exposed surface of the first lead-out pattern 331 exposed on the first surface 101 of the body 100 are substantially coplanar with each other. The second surface 102 of the body 100, the first surface 20A of the magnetic metal particles 20 and 30 exposed on the second surface 102 of the body 100, and the exposed surface of the second lead-out pattern 332 exposed on the second surface 102 of the body 100 are substantially coplanar with each other.

[0048] Magnetic metal particles 20 and 30 may be exposed on the fifth surface 105 and the sixth surface 106 of the body 100, respectively. A second surface 20B of the magnetic metal particles 20 and 30 may be formed on the magnetic metal particles 20 and 30 exposed on the fifth surface 105 and the sixth surface 106 of the body 100, and may be substantially coplanar with the fifth surface 105 and the sixth surface 106 of the body 100. Therefore, the magnetic metal particles 20 and 30 exposed on the fifth surface 105 of the body 100 may have a second surface 20B substantially coplanar with the fifth surface 105 of the body 100. The magnetic metal particles 20 and 30 exposed on the sixth surface 106 of the body 100 may also have a second surface 20B substantially coplanar with the sixth surface 106 of the body 100.

[0049] Typically, in the case of thin-film coil assemblies, coil strips comprising multiple coils and multiple bodies connected to each other can be fabricated on a large-area substrate, and the bodies of the multiple assemblies can be divided into individual assemblies by performing cuts parallel to the length direction L and width direction W of each assembly. In an example embodiment, in the process of forming multiple assemblies into coil strips (primary coil strips), a dummy pattern longer than the size of a single assembly cut along the length direction can be formed between two individual assemblies adjacent to each other in the width direction W, and the body of each assembly can be formed to have a thickness corresponding to the height of the dummy pattern. The primary coil strips formed as described above can be cut along the width direction of the assemblies, and two assemblies connected to each other in the length direction L can be separated from each other. Once the cutting process is completed, secondary coil strips with multiple assemblies adjacent to each other in the width direction W connected to each other can be formed. As described above, since the dummy pattern is formed between multiple components adjacent to each other in the width direction W, when the upper and lower surfaces of the secondary coil strip (corresponding to the upper and lower surfaces of individual components) are configured to be substantially coplanar with the upper and lower surfaces of the dummy pattern, the multiple components of the secondary coil strip that are adjacent to each other in the width direction W can be separated from each other without cutting the secondary coil strip in the length direction L. Referring to the body of a single component, since the first surface 101 and the second surface 102 of the body 100 that are opposite each other in the length direction L are formed by a cutting process, the magnetic metal particles 20 and 30 cut by the cutting saw can be exposed on the first surface 101 and the second surface 102 of the body 100. In other words, the magnetic metal particles 20 and 30 exposed on the first surface 101 and the second surface 102 of the body 100 can have a first surface 20A, which can be, for example, a cut surface. Referring to the main body of a single component, since the third surface 103 and the fourth surface 104 of the main body 100, which are opposite each other in the width direction W, are not formed by a cutting process, the magnetic metal particles 20 and 30 exposed on the third surface 103 and the fourth surface 104 of the main body 100 may not have cut surfaces. Referring to the main body of a single component, since the fifth surface 105 and the sixth surface 106 of the main body 100, which are opposite each other in the thickness direction T, can be formed by grinding or polishing the secondary coil strip in the thickness direction T, thereby dividing the secondary coil strip into individual components, the magnetic metal particles 20 and 30 can be exposed on the fifth surface 105 and the sixth surface 106 of the main body 100 by grinding or polishing. Therefore, the magnetic metal particles 20 and 30 exposed on the fifth surface 105 and the sixth surface 106 of the main body 100 may have a second surface 20B.

[0050] An oxide insulating film OL formed using the conductive material of core particles 21 and 31 can be formed on the first surface 20A of magnetic metal particles 20 and 30.

[0051] An oxide insulating film OL can be formed on a first surface 20A and a second surface 20B of magnetic metal particles 20 and 30. The oxide insulating film OL can be formed on the first surface 20A of the magnetic metal particles 20 and 30 exposed to the first surface 101 and the second surface 102 of the body 100, and on the second surface 20B of the magnetic metal particles 20 and 30 exposed to the fifth surface 105 and the sixth surface 106 of the body 100, and can be configured as an oxide film comprising the metal of the magnetic metal particles 20 and 30. The oxide insulating film OL can be formed by performing acid treatment on surfaces 101, 102, 103, 104, 105, and 106 of the body 100 after a cutting process. In this case, since the acid treatment solution can selectively react with the exposed magnetic metal particles 20 and 30 to form the oxide insulating film OL, the oxide insulating film OL can comprise the metallic components of the exposed magnetic metal particles 20 and 30.

[0052] Due to the relatively porous structure of the cured product of the insulating resin 10 of the body 100, the acid treatment solution can penetrate to a certain depth into the surfaces 101, 102, 103, 104, 105, and 106 of the body 100. Therefore, the oxide insulating film OL can be formed not only on at least a portion of the magnetic metal particles 20 and 30 exposed on the surfaces 101, 102, 103, 104, 105, and 106 of the body 100, but also on at least a portion of the magnetic metal particles 20 and 30 within a certain depth from the surfaces 101, 102, 103, 104, 105, and 106 of the body. The certain depth from the surfaces 101, 102, 103, 104, 105, and 106 of the body 100 can be defined as a depth approximately 0.5 times the particle size of the first magnetic metal particle 20.

[0053] Since the particle size of the first magnetic metal particle 20 is larger than that of the second magnetic metal particle 30, an oxide insulating film OL can typically be formed on the first surface 20A and the second surface 20B of the first magnetic metal particle 20. In other words, both the first magnetic metal particle 20 and the second magnetic metal particle 30 can be disposed within a certain depth from the first surface 101, second surface 102, fifth surface 105, and sixth surface 106 of the body 100. The second magnetic metal particle 30 can dissolve in the acid treatment solution during acid treatment due to its relatively small particle size. The second magnetic metal particle 30 can dissolve in the acid treatment solution and can form voids in the region within a certain depth from the first surface 101, second surface 102, fifth surface 105, and sixth surface 106 of the body 100. Therefore, voids corresponding to the volume of the second magnetic metal particle 30 can be retained in the insulating resin 10 disposed within a certain depth from the first surface 101, second surface 102, fifth surface 105, and sixth surface 106 of the body 100. As described above, since the particle size of the second magnetic metal particle 30 refers to the particle size according to the particle size distribution, the volume of the second magnetic metal particle 30 can also refer to the volume according to the volume distribution. Therefore, the concept that the volume of the voids corresponds to the volume of the second magnetic metal particle 30 can indicate that the volume distribution of the voids can be substantially the same as the volume distribution of the second magnetic metal particle 30.

[0054] Because at least a portion of the magnetic metal particles 20 and 30 exposed on the surfaces 101, 102, 103, 104, 105, and 106 of the body 100, and the magnetic metal particles 20 and 30 disposed at a certain depth from the surfaces 101, 102, 103, 104, 105, and 106 of the body 100, react with the acid, an oxide insulating film OL can be formed. Therefore, as... Figure 3 As shown, the oxide insulating film OL may be discontinuously formed on the first surface 101 and the second surface 102 of the body 100. Furthermore, the oxygen ion concentration in the oxide insulating film OL may decrease from the outside to the inside of the magnetic metal particles 20 and 30. In other words, since the outer surfaces of the magnetic metal particles 20 and 30 are exposed to the acid treatment solution for a longer time than the interior surfaces of the magnetic metal powder particles 20 and 30 are exposed to the acid treatment solution, the oxygen ion concentration in the oxide insulating film OL may vary with depth. Therefore, cracks may form in the oxide insulating film OL due to the imbalance of metal composition caused by the redox reaction. For the above reasons, the oxide insulating film OL in the example embodiment can be distinguished from oxide insulating films formed by coating the magnetic metal particles 20 and 30 with an oxide film or by applying an oxide film to the magnetic metal particles 20 and 30.

[0055] The main body 100 may include a core 110 passing through the support substrate 200 and the coil portion 300. The core 110 may be formed by filling a through hole passing through the central portion of each of the coil portion 300 and the support substrate 200 with a magnetic composite sheet, but exemplary embodiments thereof are not limited thereto.

[0056] The support substrate 200 can be embedded in the main body 100. The support substrate 200 can support the coil section 300.

[0057] The support substrate 200 may be formed using an insulating material including thermosetting insulating resins (such as epoxy resins), thermoplastic insulating resins (such as polyimide), or photosensitive insulating resins, or it may be formed using an insulating material prepared by impregnating reinforcing materials (such as glass fibers) and / or inorganic fillers in a thermosetting or thermoplastic insulating resin. For example, the support substrate 200 may be formed using insulating materials such as prepregs, Ajinomoto laminate (ABF), FR-4, bismaleimide triazine (BT) resin, photosensitive dielectric (PID), etc., but examples of materials for the support substrate 200 are not limited to these.

[0058] As an inorganic filler, one or more materials selected from the group consisting of silicon dioxide (SiO2), aluminum oxide (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc, clay, mica powder, 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) can be used.

[0059] When the support substrate 200 is formed using an insulating material including reinforcing material, the support substrate 200 can provide improved rigidity. When the support substrate 200 is formed using an insulating material that does not include glass fiber, the thickness of the coil assembly 1000 in the example embodiment can be reduced. Furthermore, compared to a body 100 having the same dimensions, the volume occupied by the coil portion 300 and / or the magnetic metal particles 20 and 30 can be increased, thereby improving the assembly characteristics. When the support substrate 200 is formed using an insulating material including a photosensitive insulating resin, the number of processes used to form the coil portion 300 can be reduced, thereby reducing production costs and allowing for the formation of fine vias.

[0060] The coil section 300 can be disposed in the main body 100 and can exhibit the properties of a coil assembly. For example, when the coil assembly 1000 is used as a power inductor, the coil section 300 can store an electric field as a magnetic field and maintain the output voltage, thereby stabilizing the power of the electronic device.

[0061] The coil portion 300 may include coil patterns 311 and 312, a via 320, and lead-out patterns 331 and 332. Specifically, see... Figure 1 , Figure 2 and Figure 5 In the orientation of the coil, the first coil pattern 311 and the first lead-out pattern 331 can be disposed on the lower surface of the support substrate 200 opposite to the sixth surface 106 of the main body 100, and the second coil pattern 312 and the second lead-out pattern 332 can be disposed on the upper surface of the support substrate 200 opposite to the lower surface of the support substrate 200. The via 320 can penetrate the support substrate 200 and can contact and connect to the inner ends of the first coil pattern 311 and the second coil pattern 312. The first lead-out pattern 331 and the second lead-out pattern 332 can be connected to the first coil pattern 311 and the second coil pattern 312 respectively, and can be exposed on the first surface 101 and the second surface 102 of the main body 100 respectively, and can be connected to the first external electrode 410 and the second external electrode 420 respectively. Therefore, the coil portion 300 can be used as a single coil between the first external electrode 410 and the second external electrode 420.

[0062] Each of the first coil pattern 311 and the second coil pattern 312 may have a planar spiral shape forming at least one turn around the core 110 of the body 100. As an example, the first coil pattern 311 may form at least one turn around the core 110 on the lower surface of the support substrate 200.

[0063] Outline patterns 331 and 332 may be exposed on the first surface 101 and the second surface 102 of the body 100, respectively. For example, the first outline pattern 331 may be exposed on the first surface 101 of the body 100, and the second outline pattern 332 may be exposed on the second surface 102 of the body 100.

[0064] At least one of coil patterns 311 and 312, via 320, and lead-out patterns 331 and 332 may include at least one conductive layer.

[0065] As an example, when the second coil pattern 312, via 320, and second lead-out pattern 332 are formed on the upper surface side of the support substrate 200 by a plating process, each of the second coil pattern 312, via 320, and second lead-out pattern 332 may include a seed layer and an electroplated layer. The electroplated layer may have a single-layer structure or a multi-layer structure. An electroplated layer with a multi-layer structure may be formed as a conformal film structure in which one electroplated layer is covered by another electroplated layer, or it may be formed as a structure in which another electroplated layer is laminated only on one surface of an electroplated layer. The seed layer may be formed by an electroless plating method or a vapor deposition method such as sputtering. The seed layers of the second coil pattern 312, the via 320, and the second lead-out pattern 332 may be integrated with each other so that no boundary is formed between them, but the exemplary embodiments are not limited thereto. The electroplated layers of the second coil pattern 312, the via 320, and the second lead pattern 332 can be integrated with each other so that no boundary is formed between them, but the exemplary embodiments are not limited thereto.

[0066] As another example, when a coil portion 300 is formed by forming a first coil pattern 311 and a first lead-out pattern 331 disposed on the lower surface side of the support substrate 200, and a second coil pattern 312 and a second lead-out pattern 332 disposed on the upper surface side of the support substrate 200, and then laminating the first coil pattern 311 and the first lead-out pattern 331, as well as the second coil pattern 312 and the second lead-out pattern 332 together on the support substrate 200, the via 320 may include a high-melting-point metal layer and a low-melting-point metal layer with a melting point lower than that of the high-melting-point metal layer. The low-melting-point metal layer may be formed using solder comprising lead (Pb) and / or tin (Sn). During lamination, at least a portion of the low-melting-point metal layer may melt due to pressure and temperature, and an intermetallic compound layer (IMC layer) may be formed at the boundary between the low-melting-point metal layer and the second coil pattern 312.

[0067] For example, such as Figure 1 and Figure 2 As shown, the first coil pattern 311 and the first lead-out pattern 331, along with the second coil pattern 312 and the second lead-out pattern 332, can be formed to protrude from the lower and upper surfaces of the support substrate 200, respectively. As another example, the first coil pattern 311 and the first lead-out pattern 331 can protrude from the lower surface of the support substrate 200, and the second coil pattern 312 and the second lead-out pattern 332 can be embedded in the upper surface of the support substrate 200, with the upper surface exposed. In this case, a recess can be formed on the upper surface of the second coil pattern 312 and / or the upper surface of the second lead-out pattern 332, such that the upper surface of the support substrate 200 and the upper surface of the second coil pattern 312 and / or the upper surface of the second lead-out pattern 332 are not necessarily on the same plane.

[0068] Each of the coil patterns 311 and 312, the via 320, and the lead-out patterns 331 and 332 may be formed using a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), chromium (Cr), or alloys thereof, but examples of materials are not limited thereto.

[0069] External electrodes 410 and 420 may be disposed on the main body 100, may be spaced apart from each other, and may be connected to the coil portion 300. In an example embodiment, such as Figure 2 As shown, external electrodes 410 and 420 may include pad portions 412 and 422 spaced apart from each other on the sixth surface 106 of the body 100, and connection portions 411 and 421 on the first surface 101 and the second surface 102 of the body 100. Specifically, the first external electrode 410 may include a first connection portion 411 and a first pad portion 412. The first connection portion 411 is disposed on the first surface 101 of the body 100 and contacts a first lead-out pattern 331 exposed on the first surface 101 of the body 100. The first pad portion 412 extends from the first connection portion 411 to the sixth surface 106 of the body 100. The second external electrode 420 may include a second connection portion 421 and a second pad portion 422. The second connection portion 421 is disposed on the second surface 102 of the body 100 and contacts a second lead-out pattern 332 exposed on the second surface 102 of the body 100. The second pad portion 422 extends from the second connection portion 421 to the sixth surface 106 of the body 100. The first pad portion 412 and the second pad portion 422 may be disposed on the sixth surface 106 of the main body 100 and may be spaced apart from each other. The first connecting portion 411 and the first pad portion 412 may be formed together in the same process, so that no boundary is formed between them and they can be integrated with each other; the second connecting portion 421 and the second pad portion 422 may be formed together in the same process, so that no boundary is formed between them and they can be integrated with each other, but the exemplary embodiments are not limited thereto.

[0070] The external electrodes 410 and 420 may be formed by vapor deposition methods (such as sputtering) and / or plating methods, but exemplary embodiments thereof are not limited thereto.

[0071] The external electrodes 410 and 420 may be formed using conductive materials such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or alloys thereof, but examples of materials are not limited thereto. The external electrodes 410 and 420 may be formed as a single-layer or multi-layer structure. As an example, the first external electrode 410 may include a first conductive layer comprising copper (Cu), a second conductive layer disposed on the first conductive layer and comprising nickel (Ni), and a third conductive layer disposed on the second conductive layer and comprising tin (Sn). At least one of the second and third conductive layers may be formed to cover the first conductive layer, but exemplary embodiments are not limited thereto. At least one of the second and third conductive layers may be disposed only on the sixth surface 106 of the body 100, but exemplary embodiments are not limited thereto. The first conductive layer may be a plating, or it may be a conductive resin layer formed by coating and curing a conductive powder comprising at least one of copper (Cu) and silver (Ag) and a conductive resin. The second and third conductive layers can be platings, but exemplary embodiments are not limited thereto.

[0072] An insulating layer IF may be disposed between the coil portion 300 and the body 100, and between the support substrate 200 and the body 100. The insulating layer IF may be formed along the surface of the support substrate 200 on which coil patterns 311 and 312 and lead-out patterns 331 and 332 are formed, but exemplary embodiments are not limited thereto. The insulating layer IF may be configured to insulate the coil portion 300 and the body 100, and may include commonly used insulating materials (such as parylene), but exemplary embodiments are not limited thereto. As another example, the insulating layer IF may include insulating materials (such as epoxy resins other than parylene). The insulating layer IF may be formed by a vapor deposition method, but exemplary embodiments are not limited thereto. As another example, the insulating layer IF may be formed by laminating an insulating film for forming the insulating layer IF onto both surfaces of the support substrate 200 on which the coil portion 300 is formed and curing the insulating film, or by applying an insulating paste for forming the insulating layer IF onto both surfaces of the support substrate 200 on which the coil portion 300 is formed and curing the insulating paste. As another example, the insulating layer IF may not be provided in the example embodiment. In other words, in the example embodiment, the insulating layer IF may not be provided if the body 100 has sufficient resistance at the design operating current and voltage of the coil assembly 1000.

[0073] A surface insulating layer 500 may be disposed on a first surface 101, a second surface 102, a third surface 103, a fourth surface 104, a fifth surface 105, and a sixth surface 106 of the body 100. The surface insulating layer 500 may extend from the fifth surface 105 of the body 100 to at least a portion of the first surface 101, at least a portion of the second surface 102, at least a portion of the third surface 103, at least a portion of the fourth surface 104, and at least a portion of the sixth surface 106 of the body 100. In an example embodiment, the surface insulating layer 500 may be disposed on each of the first surface 101, the second surface 102, the third surface 103, the fourth surface 104, and the fifth surface 105 of the body 100, and may be disposed in the area of ​​the sixth surface 106 of the body 100 other than the area where the pad portions 412 and 422 are provided. The surface insulating layer 500 disposed on the first surface 101 and the second surface 102 of the main body 100 can respectively cover the connection portion 411 of the external electrode 410 and the connection portion 421 of the external electrode 420.

[0074] At least a portion of the surface insulating layers 500 disposed on the first surface 101, second surface 102, third surface 103, fourth surface 104, fifth surface 105 and sixth surface 106 of the body 100 may be formed by the same process and may be integrated with each other without boundaries between them, but exemplary embodiments thereof are not limited thereto.

[0075] The surface insulating layer 500 may include thermoplastic resins (such as polystyrene resin, vinyl acetate resin, polyester resin, polyethylene resin, polypropylene resin, polyamide resin, rubber resin, acrylic resin, etc.), thermosetting resins (such as phenolic resin, epoxy resin, polyurethane resin, melamine resin, alkyd resin, etc.), photosensitive resins, parylene, SiO2, etc. x or SiN x The surface insulating layer 500 may also include insulating fillers such as inorganic fillers, but its exemplary embodiments are not limited thereto.

[0076] Therefore, in the coil assembly 1000 of the example embodiment, as Figure 6 As shown, two of the six surfaces of the body 100, side surfaces 103 and 104, may not be cut, thus the magnetic metal powder particles 20 and 30 may not be cut. Therefore, when dividing and separating the body of multiple components by cutting coil strips, the cutting process typically performed along the length direction L can be omitted. Furthermore, since the core particles of the magnetic metal particles 20 and 30 are not exposed on the third surface 103 and the fourth surface 104 of the body 100, leakage current can be reduced. Additionally, short circuits with other components mounted adjacent to each other along the width direction W on a mounting substrate (such as a printed circuit board) can be prevented.

[0077] Figure 7 This is a perspective view showing a coil assembly according to another example embodiment. Figure 8 It is along Figure 7 The cross-sectional view taken from line III-III' in the diagram. Figure 9 It is shown Figure 8 Enlarged views of parts D and D' in the image.

[0078] Figure 10 It is shown Figure 8 Enlarged views of parts E and E' in the image. Figure 11 It is along Figure 7 The cross-sectional view taken from line IV-IV' in the diagram. Figure 12 It is shown Figure 11 A magnified view of part F in the image.

[0079] Reference Figures 7 to 12 In the coil assembly 2000 of the example embodiment, the arrangement of the coil portion 300 and the surface of the body 100 (on which the magnetic metal particles 20 and 30 having the first surface 20A are exposed) may differ from those of the coil assembly 1000 described in the foregoing example embodiments. Therefore, in this example embodiment, only the arrangement of the coil portion 300 and the surface of the body 100 (on which the magnetic metal particles 20 and 30 having the first surface 20A are exposed) that may differ from those of the foregoing example embodiments will be described, and the description of other elements in this example embodiment may be the same as the description of other elements in the foregoing example embodiments.

[0080] Reference Figures 7 to 12 The main body 100 may include a first surface 101 and a second surface 102 opposite to each other in the length direction L, a third surface 103 and a fourth surface 104 opposite to each other in the width direction W, and a fifth surface 105 and a sixth surface 106 opposite to each other in the thickness direction T. The first surface 101, the second surface 102, the third surface 103, and the fourth surface 104 of the main body 100 may be walls of the main body 100 that connect the fifth surface 105 of the main body 100 to the sixth surface 106. In the following description, the two end surfaces (one end surface and the other end surface) of the main body 100 may refer to the first surface 101 and the second surface 102 of the main body 100, the two side surfaces (one side surface and the other side surface) of the main body 100 may refer to the third surface 103 and the fourth surface 104 of the main body 100, and one surface and the other surface of the main body 100 may refer to the sixth surface 106 and the fifth surface 105 of the main body 100, respectively.

[0081] The body 100 may be configured such that the coil assembly 2000, on which the outer electrodes 410 and 420 and the surface insulating layer 500 are formed, may have, for example, a length of 1.0 mm, a width of 0.5 mm, and a thickness of 0.8 mm, but exemplary embodiments thereof are not limited thereto. The dimensions described above are exemplary dimensions determined without taking into account manufacturing errors, and examples of dimensions are not limited thereto.

[0082] A coil portion 300 may be disposed on a support substrate 200. The coil portion 300 may be embedded in the body 100 and may exhibit the properties of a coil assembly. The coil portion 300 may be formed on at least one of two opposing surfaces of the support substrate 200 and may form at least one turn. The coil portion 300 may be disposed on one and another opposing surfaces of the support substrate 200 in the width direction W of the body 100, and may be configured as a sixth surface 106 perpendicular to the body 100. In an example embodiment, the coil portion 300 may include coil patterns 311 and 312, a via 320, and a first lead-out and a second lead-out.

[0083] Each of the first coil pattern 311 and the second coil pattern 312 may have a planar spiral shape forming at least one turn around the core 110 of the body 100. As an example, see... Figure 7 In the direction of the core 110, the first coil pattern 311 may form at least one turn around the core 110 on the rear surface of the support substrate 200. The second coil pattern 312 may form at least one turn around the core 110 on the front surface of the support substrate 200. In each of the first coil pattern 311 and the second coil pattern 312, the end of the outermost turn connected to the lead-out patterns 331 and 332 may be closer to the sixth surface 106 side of the body 100 than the central portion of the body 100 in the thickness direction T. Therefore, in the first coil pattern 311 and the second coil pattern 322, compared to the example where the end of the outermost turn of the coil is only formed up to the central portion of the body in the thickness direction, the number of turns of the entire coil portion 300 can be increased.

[0084] The first lead-out portion may include a lead-out pattern and an auxiliary lead-out pattern, and the second lead-out portion may include a lead-out pattern and an auxiliary lead-out pattern. Specifically, refer to... Figure 7 In the direction of the first lead-out portion, the first lead-out portion may include a first lead-out pattern 331 and a first auxiliary lead-out pattern 341. The first lead-out pattern 331 extends from a first coil pattern 311 located on the rear surface of the support substrate 200 and is exposed on the sixth surface 106 of the body 100. The first auxiliary lead-out pattern 341 is disposed on the front surface of the support substrate 200 to correspond to the first lead-out pattern 331 and spaced apart from the second coil pattern 312. (See reference...) Figure 7In the direction of the first lead-out portion, the second lead-out portion may include a second lead-out pattern 332 and a second auxiliary lead-out pattern (not shown). The second lead-out pattern 332 extends from the second coil pattern 311 located on the front surface of the support substrate 200 and is exposed on the sixth surface 106 of the body 100. The second auxiliary lead-out pattern is disposed on the rear surface of the support substrate 200 to correspond to the second lead-out pattern 332 and spaced apart from the first coil pattern 311. The first lead-out portion and the second lead-out portion may be exposed on the sixth surface of the body 100 and may be spaced apart from each other, and may contact and be connected to the first external electrode 410 and the second external electrode 420, respectively. Through-hole portions (not shown) penetrating the lead-out pattern and the auxiliary lead-out pattern may be formed in the lead-out pattern and the auxiliary lead-out pattern. In this case, since at least a portion of the body 100 is disposed in the through-hole portion, the bonding force (anchoring effect) between the body 100 and the coil portion 300 may be improved. Furthermore, the through-hole portion may penetrate the support substrate 200 disposed between the lead-out pattern and the auxiliary lead-out pattern, but the exemplary embodiments are not limited thereto.

[0085] Considering the electrical connection between the coil portion 300 and the external electrodes 410 and 420, the auxiliary lead-out pattern described above may not be provided in the example embodiment. Therefore, in another example embodiment, the auxiliary lead-out pattern may also be omitted. In an example where the auxiliary lead-out pattern is formed symmetrically with the lead-out pattern in terms of position and size, the external electrodes 410 and 420 formed on the sixth surface 106 of the body 100 can be formed symmetrically, thereby reducing appearance defects.

[0086] The first via 320 penetrates the support substrate 200 and connects the innermost ends of the innermost turns of the first coil pattern 311 and the second coil pattern 312 to each other. The second via penetrates the support substrate 200 and connects the first lead-out pattern 331 to the first auxiliary lead-out pattern 341. The third via penetrates the support substrate 200 and connects the second lead-out pattern 332 to the second auxiliary lead-out pattern. Therefore, the coil portion 300 can be used as a single coil.

[0087] As described above, since the auxiliary lead-out pattern is independent of the electrical connection between the coil portion 300 and the external electrodes 410 and 420, the second and third vias may not be provided in the example embodiment. However, as in the example embodiment, when the lead-out pattern is connected to the auxiliary lead-out pattern through the second and third vias, the connection reliability between the coil portion 300 and the external electrodes 410 and 420 can be improved.

[0088] At least one of the coil patterns 311 and 312, the first via 320, the lead-out pattern, and the auxiliary lead-out pattern may include at least one conductive layer.

[0089] As an example, when plated on the front surface of the support substrate 200 (refer to...) Figure 7 When the second coil pattern 312, the first via 320, the second lead-out pattern 332, and the first auxiliary lead-out pattern 341 are formed on the direction of the coil, each of the second coil pattern 312, the first via 320, the second lead-out pattern 332, and the first auxiliary lead-out pattern 341 may include a seed layer and an electroplated layer. The seed layer may be formed by electroless plating or vapor deposition methods (such as sputtering). Each of the seed layer and the electroplated layer may have a single-layer structure or a multi-layer structure. An electroplated layer with a multi-layer structure may be formed as a conformal film structure in which one electroplated layer is covered by another electroplated layer, or it may be formed as a structure in which another electroplated layer is laminated only on one surface of an electroplated layer. The seed layer of the second coil pattern 312, the seed layer of the first via 320, and the seed layer of the second lead-out pattern 332 may be integrated with each other so that no boundary is formed between them, but the exemplary embodiments thereof are not limited thereto. The electroplated layers of the second coil pattern 312, the first via 320, and the second lead-out pattern 332 can be integrated with each other so that no boundary is formed between them, but exemplary embodiments are not limited thereto.

[0090] Each of the coil patterns 311 and 312, the first via 320, the lead-out patterns 331 and 332, and the auxiliary lead-out patterns 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 alloys thereof), but examples of materials are not limited thereto.

[0091] In the example embodiment, since the coil portion 300 is disposed perpendicular to the sixth surface 106 (mounting surface) of the main body 100, the volume of the main body 100 and the volume of the coil portion 300 can be maintained, and the mounting area can be reduced. Therefore, a greater number of electronic components can be mounted on a mounting substrate of the same size. Furthermore, in the example embodiment, since the coil portion 300 is disposed perpendicular to the sixth surface 106 (mounting surface) of the main body 100, the direction of the magnetic flux induced by the coil portion 300 to the core 110 can be parallel to the sixth surface 106 of the main body 100. Therefore, noise generated on the mounting surface of the mounting substrate can be relatively reduced.

[0092] The first surface 20A of the magnetic metal particles 20 and 30 may be formed only on the magnetic metal particles 20 and 30 exposed to the sixth surface 106 of the body 100. The second surface 20B of the magnetic metal particles 20 and 30 may be formed only on the magnetic metal particles 20 and 30 exposed to the third surface 103 and the fourth surface 104 of the body 100. In other words, the magnetic metal particles 20 and 30 may be exposed to each of the first surface 101, the second surface 102, the third surface 103, the fourth surface 104, the fifth surface 105, and the sixth surface 106 of the body 100, and the first surface 20A (cut surface) and the second surface 20B (grinding surface or polishing surface) may not be formed on the magnetic metal particles 20 and 30 exposed to each of the first surface 101, the second surface 102, and the fifth surface 105 of the body 100. Here, the cut surface, the grinding surface, and the polishing surface may be substantially flat surfaces. Those skilled in the art will understand that the expression "substantially flat surface" means that the plane is flat, taking into account process errors, positional deviations and / or measurement errors that may occur in the manufacturing process.

[0093] In the example embodiment, since the magnetic composite sheet used to form the primary coil strip is laminated along the width direction of a single component, a polishing process can be performed on the third and fourth surfaces of the body 100 to expose the aforementioned dummy pattern. Therefore, the magnetic metal particles 20 and 30 exposed on the third surface 103 and fourth surface 104 of the body 100 may have a second surface 20B (a polished or ground surface). In the example embodiment, the aforementioned dummy pattern may be provided between components adjacent to each other in the length direction L of the primary coil strip, and between components adjacent to each other in the thickness direction T at the fifth surface 105 of the body 100. Therefore, referring to a single component, since the first surface 101, second surface 102, and fifth surface 105 of the body 100 are not formed by a cutting process, the magnetic metal particles do not have cut surfaces exposed to each of the first surface 101, second surface 102, and fifth surface 105 of the body 100.

[0094] In the example embodiment, the components can be separated from each other by performing a cutting process only on the sixth surface 106 of the body 100. Therefore, the process of cutting the coil strips can be further omitted. Furthermore, since the core particles of the magnetic metal particles 20 and 30 are not exposed on the first surface 101, second surface 102, and fifth surface 105 of the body 100, leakage current can be reduced. Additionally, short circuits with other components mounted adjacent to each other along the length direction L on a mounting substrate (such as a printed circuit board) can be prevented.

[0095] According to the above example embodiment, the cutting process performed along the length direction L and width direction W of the coil assembly can be omitted.

[0096] While exemplary embodiments have been shown and described above, it will be readily understood by those skilled in the art that modifications and variations may be made without departing from the scope of this disclosure as defined by the appended claims.

Claims

1. A coil assembly, comprising: The body has a first surface and a second surface opposite to each other and a plurality of wall surfaces connecting the first surface to the second surface, and includes insulating resin and magnetic metal particles; An insulating substrate is disposed in the main body; A coil portion is disposed on the insulating substrate and includes a lead-out pattern on a first wall surface exposed to the plurality of wall surfaces of the body; as well as External electrodes are disposed on the main body and connected to the lead-out pattern. In this embodiment, some of the magnetic metal particles are exposed on each of the plurality of wall surfaces of the body. The magnetic metal particles exposed on the first wall surface of the main body have slit surfaces, and The magnetic metal particles on the second wall surface of the plurality of wall surfaces exposed on the main body do not have a cut surface, and the second wall surface is connected to the first wall surface.

2. The coil assembly according to claim 1, wherein, The cut surface of the magnetic metal particle is substantially coplanar with the exposed surface of the first wall surface of the body of the lead-out pattern.

3. The coil assembly according to claim 1, in, Each of the magnetic metal particles comprises a conductive core particle and an insulating coating covering the core particle, and The core particles of the magnetic metal particles exposed on the first wall surface of the main body are formed on the cut surface of the magnetic metal particles.

4. The coil assembly according to claim 3, wherein, An oxide insulating film of the conductive material of the core particle is disposed on the cut surface of the magnetic metal particle.

5. The coil assembly according to claim 1, wherein, The magnetic metal particles exposed on each of the first and second surfaces of the body have polished or ground surfaces.

6. The coil assembly according to claim 5, in, The plurality of wall surfaces of the body have a first side surface and a second side surface opposite to each other, and a first end surface and a second end surface that connect the first side surface to the second side surface and are opposite to each other. The lead-out pattern includes a first lead-out pattern exposed on the first end surface of the body and a second lead-out pattern exposed on the second end surface of the body. The magnetic metal particles exposed on each of the first and second end surfaces of the body have slit surfaces, and The magnetic metal particles exposed on the first and second side surfaces of the body do not have cut surfaces.

7. The coil assembly according to claim 6, wherein, The magnetic metal particles exposed on the first side surface of the body are not coplanar with the first side surface of the body, and the magnetic metal particles exposed on the second side surface of the body are not coplanar with the second side surface of the body.

8. The coil assembly according to claim 6, wherein, The external electrode includes a first external electrode and a second external electrode. The first external electrode is disposed on the first end surface of the body, contacts the first lead-out pattern, and extends to the first surface of the body. The second external electrode is disposed on the second end surface of the body, contacts the second lead-out pattern, and extends to the first surface of the body.

9. The coil assembly according to claim 5, in, The plurality of wall surfaces of the body have a first side surface and a second side surface opposite to each other, and a first end surface and a second end surface that connect the first side surface to the second side surface and are opposite to each other. The lead-out pattern includes a first lead-out pattern and a second lead-out pattern that are exposed on the first end surface of the body and spaced apart from each other. The magnetic metal particles that are only exposed on the first end surface of the body have cut surfaces.

10. The coil assembly according to claim 9, wherein, The magnetic metal particles exposed on the first side surface, the second side surface, and the second end surface of the body are not coplanar with the first side surface, the second side surface, and the second end surface of the body, respectively.

11. A coil assembly, comprising: The body has a first surface and a second surface opposite to each other and a plurality of wall surfaces connecting the first surface to the second surface, and includes insulating resin and magnetic metal particles; A coil portion is disposed in the body and includes a lead-out pattern on a first wall surface exposed to the plurality of wall surfaces of the body; as well as An external electrode is disposed on the first surface of the body and connected to the lead-out pattern. Some of the magnetic metal particles are exposed on each of the plurality of wall surfaces of the body. The exposed portion of the magnetic metal particles on the first wall surface of the body has a substantially flat surface, and Wherein, the exposed portion of the magnetic metal particles on the second wall surface of the body does not have a substantially flat surface, and the second wall surface of the body is connected to the first wall surface of the body among the plurality of wall surfaces of the body.

12. The coil assembly according to claim 11, wherein, The flat surface of the magnetic metal particle is substantially coplanar with the exposed surface of the first wall surface of the body of the lead-out pattern.

13. The coil assembly according to claim 11, in, Each of the magnetic metal particles comprises a conductive core particle and an insulating coating covering the core particle, and The core particles of the magnetic metal particles exposed on the first wall surface of the main body form the flat surface of the magnetic metal particles.

14. The coil assembly of claim 13, wherein, An oxide insulating film of the conductive material of the core particle is disposed on the flat surface of the magnetic metal particle.

15. The coil assembly of claim 11, wherein, The plurality of wall surfaces of the body have a first side surface and a second side surface opposite to each other, and a first end surface and a second end surface that connect the first side surface to the second side surface and are opposite to each other. The lead-out pattern includes a first lead-out pattern exposed on the first end surface of the body and a second lead-out pattern exposed on the second end surface of the body. The magnetic metal particles exposed on each of the first and second end surfaces of the body have slit surfaces, and The magnetic metal particles exposed on the first and second side surfaces of the body do not have cut surfaces.

16. The coil assembly of claim 15, wherein, The magnetic metal particles exposed on each of the first and second side surfaces of the body do not have substantially flat surfaces.

17. A coil assembly, comprising: The main body consists of insulating resin and magnetic metal particles; An insulating substrate is disposed in the main body; A coil portion is disposed on the insulating substrate and includes a lead-out pattern exposed from the body; as well as External electrodes are disposed on the main body and connected to the lead-out pattern. Among them, some of the magnetic metal particles are exposed on each of the outer surfaces of the body, and Among all the magnetic metal particles included in the body, only the magnetic metal particles exposed to the first surface of the body have a cut surface, wherein the lead-out pattern is exposed to the first surface of the body.

18. The coil assembly of claim 17, wherein, The magnetic metal particles exposed on the second surface of the body do not have a cut surface, and the second surface of the body is connected to the first surface of the body.

19. The coil assembly of claim 18, wherein, The body has a third surface connected to the first surface and the second surface of the body, and The magnetic metal particles exposed on the third surface of the body have substantially flat surfaces.

20. The coil assembly of claim 19, wherein, An oxide insulating film is provided on the cut surface of the magnetic metal particles exposed to the first surface of the body, and An oxide insulating film is provided on the flat surface of the magnetic metal particles exposed on the third surface of the body.

Images