Coil assembly

Abstract

This disclosure provides a coil assembly comprising: a body including magnetic particles and an insulating film disposed on the surface of the magnetic particles; a coil disposed in the body; and an external electrode disposed on a first surface of the body. The magnetic particles include a first magnetic particle in contact with the external electrode and a second magnetic particle not in contact with the external electrode. A portion of the insulating film is in contact with each of the second magnetic particle and the external electrode.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0197221, filed on December 26, 2024, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

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

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

[0004] In a coil assembly with an electrode structure on its lower surface, a copper (Cu) plating layer can be formed on the lower surface of the substrate using an electrochemical method when forming the outer electrode. When the particles are exposed on the lower surface of the substrate, the adhesion between the substrate and the seed layer may be weakened due to the insulating coating on the particles. As a result, problems such as poor plating of the outer electrode may occur. Summary of the Invention

[0005] One aspect of this disclosure is to provide a coil assembly with improved adhesion between the body and the external electrode.

[0006] Another aspect of this disclosure is to provide a coil assembly with improved withstand voltage characteristics.

[0007] According to one aspect of this disclosure, a coil assembly is provided, the coil assembly comprising: a body including magnetic particles and an insulating film disposed on the surface of the magnetic particles; a coil disposed in the body; and an external electrode disposed on a first surface of the body. The magnetic particles may include a first magnetic particle in contact with the external electrode and a second magnetic particle not in contact with the external electrode. A portion of the insulating film may be in contact with the second magnetic particle and the external electrode.

[0008] According to another aspect of this disclosure, a coil assembly is provided, the coil assembly comprising: a body including magnetic particles and an insulating film disposed on the surface of the magnetic particles; a coil disposed in the body; and an external electrode disposed on a first surface of the body, wherein the magnetic particles include a first magnetic particle in contact with the external electrode and a second magnetic particle not in contact with the external electrode, and the area on the first surface in which the first magnetic particles are distributed is smaller than the area on the first surface in which the external electrode is disposed.

[0009] According to exemplary embodiments of this disclosure, the adhesion between the body of the coil assembly and the external electrode can be improved.

[0010] According to exemplary embodiments of this disclosure, the coil assembly may have improved voltage withstand characteristics. Attached Figure Description

[0011] The above and other aspects, features and advantages of this disclosure will become clearer from the following detailed embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment of the present disclosure; Figure 2 It is along Figure 1 A cross-sectional view taken from line I-I'; Figure 3 It is along Figure 1 A cross-sectional view taken from line II-II'; Figure 4 yes Figure 3 An enlarged view of part A; Figure 5 yes Figure 3 An enlarged view of Part B; and Figure 6 yes Figure 1 A bottom view of the coil assembly. Detailed Implementation

[0012] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. As used herein, the term “and / or” includes any one of the associated listed items and / or any combination of any two or more items. It will also be understood that when the terms “comprising” and / or “including” are used herein, these terms enumerate the presence of the stated features, quantities, steps, operations, elements, components, or combinations thereof, without excluding the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or combinations thereof. Furthermore, the terms “set on,” “positioned on,” etc., may mean that an element is positioned “above” or “below” the target portion, and may not necessarily mean that the element is positioned above the target portion relative to the direction of gravity.

[0013] The terms “integrated into” and “connected to” can indicate not only that elements are physically in contact with each other, but can also include a configuration in which another element is located between elements such that the element is also in contact with the other element.

[0014] For ease of description, the dimensions (e.g., thickness) of the various elements shown in the accompanying drawings are shown arbitrarily, but this disclosure is not limited to the dimensions shown herein.

[0015] In the accompanying drawings, the X direction can be defined as a first direction or the thickness direction, the Y direction can be defined as a second direction or the length direction, and the Z direction can be defined as a third direction or the width direction.

[0016] In the following description, a coil assembly according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In the description with reference to the drawings, the same elements are indicated by the same reference numerals, and repeated descriptions thereof will be omitted.

[0017] Various types of electronic components can be used in electronic devices, and various types of coil assemblies can be appropriately used among such electronic components to remove noise.

[0018] In other words, in electronic devices, coil assemblies can be used as power inductors, high-frequency inductors, ordinary ferrite beads, high-frequency ferrite beads (e.g., ferrite beads suitable for the GHz band), common-mode filters, etc.

[0019] Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment of the present disclosure. Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'. Figure 3 It is along Figure 1 The cross-sectional view taken from line II-II'. Figure 4 yes Figure 3 An enlarged view of part A. Figure 5 yes Figure 3 An enlarged view of part B. Figure 6 yes Figure 1 A bottom view of the coil assembly.

[0020] Reference Figures 1 to 6 According to an example embodiment of the present disclosure, the coil assembly 1000 may include a body 100, a support member 200, a coil 300, external electrodes 400 and 500, and an insulating layer 600, and may also include a coil insulating film IF.

[0021] The body 100 may form the appearance of the coil assembly 1000 according to this example embodiment, and the coil 300 and the support member 200 may be disposed in the body 100.

[0022] The main body 100 can have a hexahedral shape as a whole.

[0023] exist Figures 1 to 3In the direction of the first direction (X direction), the body 100 may have a first surface 101 and a second surface 102 opposite to each other in the first direction (X direction), a third surface 103 and a fourth surface 104 opposite to each other in the second direction (Y direction), and a fifth surface 105 and a sixth surface 106 opposite to each other in the third direction (Z direction). The third surface 103, the fourth surface 104, the fifth surface 105, and the sixth surface 106 of the body 100 may be side surfaces of the body 100 that connect the first surface 101 and the second surface 102 of the body 100 to each other. In the following, the first surface 101 of the body 100 may refer to the lower surface of the body, but this disclosure is not limited thereto.

[0024] For example, the body 100 may be configured such that the coil assembly 1000 according to this example embodiment, including the external electrodes 400 and 500 described below and the insulating layer 600, has a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.65 mm, but this disclosure is not limited thereto. The above values ​​are merely design values ​​that do not reflect process errors, etc., and therefore, dimensions within the allowable range of process errors should be considered to fall within the scope of this disclosure.

[0025] The body 100 may include a core 110 that passes through the support member 200 and the coil 300, which will be described below. The core 110 may be formed by filling a through-hole passing through the central portion of each of the coil 300 and the support member 200 with a magnetic composite sheet, but this disclosure is not limited thereto.

[0026] The main body 100 may include magnetic particles 11 and 12 and insulating films 11F and 12F disposed on the surfaces of the magnetic particles 11 and 12.

[0027] Magnetic particles 11 and 12 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 particles 11 and 12 may be at least one selected from pure iron particles, Fe-Si based alloy particles, Fe-Si-Al based alloy particles, Fe-Ni based alloy particles, Fe-Ni-Mo based alloy particles, Fe-Ni-Mo-Cu based alloy particles, Fe-Co based alloy particles, Fe-Ni-Co based alloy particles, Fe-Cr based alloy particles, Fe-Cr-Si based alloy particles, Fe-Si-Cu-Nb based alloy particles, Fe-Ni-Cr based alloy particles, and Fe-Cr-Al based alloy particles.

[0028] Magnetic particles 11 and 12 may be amorphous or crystalline. For example, magnetic particles 11 and 12 may be Fe-Si-B-Cr based amorphous alloy particles, but this disclosure is not limited thereto. Magnetic particles 11 and 12 may have an average diameter of about 0.1 μm to about 30 μm, but this disclosure is not limited thereto.

[0029] Magnetic particles 11 and 12 may comprise two or more types of magnetic particles. Here, different types of magnetic particles may mean that the magnetic particles dispersed in the resin are distinguished from each other in one of the following aspects: average diameter, composition, crystallinity, and shape. For example, as Figure 4 As shown, magnetic particles 11 and 12 may include multiple magnetic particles with different particle sizes.

[0030] Insulating films 11F and 12F may be formed on the surfaces of magnetic particles 11 and 12, respectively. Insulating films 11F and 12F may individually or in combination comprise, for example, epoxy resin, polyimide, liquid crystal polymer, etc., or may comprise silicon dioxide (SiO2), or may be an oxide film of a metal (e.g., aluminum oxide (Al2O3)), wherein the metal may be a metal present in the magnetic particles.

[0031] The body 100 may include a resin. The body 100 may have magnetic particles 11 and 12 dispersed in the resin. The composition of the resin differs from the insulating films 11F and 12F formed on the surface of the magnetic particles. The body according to this exemplary embodiment may be formed by laminating one or more magnetic composite sheets comprising resin and magnetic particles 11 and 12 dispersed in the resin.

[0032] The resin may include, alone or in combination, epoxy resin, polyimide, liquid crystal polymer, etc., but this disclosure is not limited thereto.

[0033] Reference Figure 4 Magnetic particles 11 and 12 may include a first magnetic particle 11 that is in contact with the external electrode, which will be described below, and a second magnetic particle 12 that is not in contact with the external electrode.

[0034] The first magnetic particle 11 may extend to the first surface 101 of the body 100. In this case, a portion of the first magnetic particle 11 may protrude further relative to the first surface 101. In other words, due to the protrusion of a portion of the first magnetic particle 11, a portion of the first surface 101 may have a relatively large roughness. The insulating film 11F may not be disposed on the protruding portion of the first magnetic particle 11. That is, the insulating film 11F may not be disposed on a portion of the surface of the first magnetic particle 11, such that the first magnetic particle 11 can contact the external electrodes 400 and 500.

[0035] In a coil assembly with an electrode structure on its lower surface, a copper (Cu) plating layer can be formed on the lower surface of the substrate using an electrochemical method when forming the outer electrode. When the particles are exposed on the lower surface of the substrate, the adhesion between the substrate and the seed layer may be weakened due to the insulating coating on the particles. As a result, problems such as poor plating of the outer electrode may occur.

[0036] In the coil assembly 1000 according to this example embodiment, the insulating film 11F on the portion of the first magnetic particle 11 exposed on the surface of the first surface 101 of the body can be partially removed (e.g., the portion of the insulating film 11F disposed on the surface of the protruding portion of the first magnetic particle 11 can be removed), and the plating of each of the outer electrodes 400 and 500 can be directly formed on the surface of the first magnetic particle 11. That is, the first magnetic particle 11 can be used as a seed during the plating of the outer electrodes 400 and 500. The surface of the first magnetic particle 11 with the insulating film 11F removed can have a surface roughness (i.e., the surface roughness of the surface of the first magnetic particle 11 with the insulating film 11F removed can be relatively large) such that the outer electrodes can be stably formed on the first surface 101 of the body.

[0037] The first magnetic particle 11 extending to the first surface 101 of the body may have a circular or elliptical cross-section. Conversely, as will be described below, portions of the first magnetic particle 11 extending to the third and fourth surfaces 104 of the body may have cut surfaces. The first surface 101 of the body may be the lower surface of the body 100 of the coil assembly 1000 according to this example embodiment, and the lower surface may not undergo a cutting process. Therefore, when observed in a cross-sectional sample, the first magnetic particle 11 extending to the first surface 101 of the body may maintain a curved profile and may have a complete circular or elliptical cross-section. Furthermore, as Figure 4 As shown, at least a portion of the first magnetic particle 11 extending to the first surface 101 can protrude from the first surface 101 while maintaining a circular or elliptical cross-section.

[0038] Only a portion of the insulating film 11F disposed on the first magnetic particle 11 can be removed. (See reference...) Figure 4 An insulating film 11F can be retained on the surface of the first magnetic particle 11 that is not exposed to the first surface 101.

[0039] Figure 6 yes Figure 1 A bottom view of the coil assembly. For ease of description, in Figure 6 The insulation layer 600 is omitted.

[0040] Reference Figure 6The region R11 on the first surface 101 of the main body where the first magnetic particles 11 are distributed can be smaller than the region on the first surface 101 where the external electrodes 400 and 500 are disposed. Specifically, as shown in the figure... Figure 6 As shown, the lengths of region R11 in the Y direction (second direction) and Z direction (third direction) may be smaller than the lengths of the regions where external electrodes 400 and 500 are disposed in the Y direction (second direction) and Z direction (third direction), respectively. These lengths can be measured using a microscope (e.g., an optical microscope or an electron microscope). Other methods and / or other tools understood by those skilled in the art may be used even if not described in this disclosure.

[0041] When the insulating film of the magnetic particles is removed from the entire area on the first surface 101 of the body where the external electrodes 400 and 500 are disposed, the coil assembly may have degraded withstand voltage characteristics. Therefore, the withstand voltage characteristics can be improved by removing the insulating film 11F only from the first magnetic particles 11 on the first surface 101 of the body where the external electrodes 400 and 500 are disposed.

[0042] A portion of the first magnetic particle 11 may extend to the third surface 103 and the fourth surface 104 of the body 100 and may contact the first external electrode 400 and the second external electrode 500. The portion of the first magnetic particle 11 extending to the third surface 103 and the fourth surface 104 of the body 100 may have a cut surface. The third surface 103 and the fourth surface 104 of the body 100 may be cut surfaces of a coil assembly. Typically, in manufacturing thin-film coil assemblies, multiple coil strips interconnected with each other and multiple bodies interconnected are formed on a large-area substrate, and cuts are performed in a second direction (Y direction) and a third direction (Z direction) to individualize the bodies of the multiple coil assemblies. Therefore, the first magnetic particle 11 extending to the third surface 103 and the fourth surface 104 of the body 100 of the coil assembly according to this exemplary embodiment may have a cut surface. The insulating film 11F may also be removed during the cutting process, so that the insulating film is not disposed on the cut surface of the first magnetic particle 11. Furthermore, the cut surface may be coplanar with the third surface 103 and the fourth surface 104 of the body, and the first magnetic particle 11 may not protrude from the third surface 103 and the fourth surface 104.

[0043] A portion of the second magnetic particle 12 may extend to the first surface 101 of the body 100. In this case, a portion of the second magnetic particle 12 may protrude from the first surface 101. However, unlike the first magnetic particle 11 described above, the insulating film 12F disposed on the second magnetic particle 12 extending to the first surface 101 may not be removed. Therefore, the second magnetic particle 12 may have the following positional relationship with the external electrodes 400 and 500 or the insulating layer 600.

[0044] A portion of the second magnetic particle 12 may have an insulating film 12F that contacts the external electrodes 400 and 500. (Refer to...) Figure 4 A portion of the insulating film 12F contacts each of the second magnetic particle 12 and the first external electrode 400. As described above, since the insulating film 12F is not removed from the remaining second magnetic particles 12 (excluding the first magnetic particle 11) in the areas where the external electrodes 400 and 500 are disposed, the breakdown voltage characteristics are improved. Therefore, a portion of the second magnetic particle 12 can be positioned further outward in the second direction (Y direction) relative to the insulating layer 600 (described later) than the body 100. Since the insulating layer 600 is disposed only between the two external electrodes in the second direction (Y direction), while the second magnetic particles 12 can be distributed throughout the entire body 100, a portion of the second magnetic particle 12 can be positioned further outward in the second direction (Y direction) than the insulating layer 600 (i.e., Figure 4 (Left side of the middle). (Refer to...) Figure 4 Some of the second magnetic particles 12 are located outside the body 100 relative to the boundary between the insulating layer 600 and the first external electrode 400. Furthermore, referring to... Figure 6 The second magnetic particles 12 can be distributed in the remaining area of ​​the first surface 101 of the body 100, excluding region R11. Therefore, a portion of the second magnetic particles 12 can be distributed in the area on the first surface 101 where the external electrodes 400 and 500 are disposed.

[0045] A portion of the second magnetic particle 12 may have an insulating film 12F in contact with the insulating layer 600. That is, a portion of the insulating film 12F may be disposed between the second magnetic particle 12 and the insulating layer 600.

[0046] The support member 200 may be embedded in the main body 100. The support member 200 may be configured to support the coil 300, which will be described below.

[0047] The support member 200 may be formed using an insulating material including a thermosetting insulating resin (such as epoxy resin), a thermoplastic insulating resin (such as polyimide), or a photosensitive insulating resin, or using an insulating material prepared by impregnating a reinforcing material (such as glass fiber or inorganic filler) into the aforementioned insulating resin. For example, the support member 200 may be formed using an insulating material such as a prepreg, Ajinomoto build-up film (ABF), FR-4, bismaleimide triazine (BT) resin, photosensitive dielectric (PID), etc., but this disclosure is not limited thereto.

[0048] As an inorganic filler, at least one 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)3), 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.

[0049] When the support member 200 is formed using an insulating material including reinforcing material, the support member 200 can provide superior rigidity. When the support member 200 is formed using an insulating material that does not include glass fibers, it is advantageous to reduce the thickness of the coil assembly 1000 according to this example embodiment. Furthermore, when the support member 200 is formed using an insulating material that does not include glass fibers, the volume occupied by the coil 300 and / or magnetic particles 11 and 12 can be increased when the body 100 has the same dimensions, which can improve the characteristics of the coil assembly. When the support member 200 is formed using an insulating material including a photosensitive insulating resin, the number of processes used to form the coil 300 can be reduced, which can help reduce production costs and allows for the formation of fine vias.

[0050] The coil 300 may be disposed in the support member 200 to exhibit the characteristics of the coil assembly. For example, when the coil assembly 1000 according to this example embodiment is used as a power inductor, the coil 300 may be used to stabilize the power of the electronic device by storing the electric field as a magnetic field and maintaining the output voltage.

[0051] The coil 300 may include coil patterns 310 and 320 and a via 330. Specifically, in Figures 1 to 3 In the direction of the first coil pattern 310, a first coil pattern 320 may be disposed on the upper surface of the support member 200 opposite to the second surface 102 of the body 100, and a second coil pattern 320 may be disposed on the lower surface of the support member 200 opposite to the upper surface of the support member 200. A through hole 330 may pass through the support member 200 and connect the first coil pattern 310 and the second coil pattern 320 to each other. Therefore, the coil 300 can be used as a single coil between the first external electrode 400 and the second external electrode 500.

[0052] Each of the first coil pattern 310 and the second coil pattern 320 may have a planar spiral shape forming at least one turn using the core 110 as an axis. For example, in Figure 1 and Figure 2In the direction of the first coil pattern 310, multiple turns can be formed on the upper surface of the support member 200 using the core 110 as the axis. The second coil pattern 320 can be formed on the lower surface of the support member 200 using the core 110 as the axis.

[0053] One end of the first coil pattern 310 may extend to the third surface 103 of the body and may be connected to the first external electrode 400, which will be described below, and the other end of the first coil pattern 310 may be connected to the via 330. One end of the second coil pattern 320 may extend to the fourth surface 104 of the body and may be connected to the second external electrode 500, which will be described below, and the other end of the second coil pattern 320 may be connected to the via 330.

[0054] At least one of the coil patterns 310 and 320 and the via 330 may include at least one conductive layer.

[0055] For example, when the first coil pattern 310 and the via 330 are formed by plating, each of the first coil pattern 310 and the via 330 may include a seed layer formed by electroless plating or vapor deposition (such as sputtering) and an electrolytic plating layer. Here, the electrolytic plating layer may have a single-layer structure or a multi-layer structure. An electrolytic plating layer with a multi-layer structure may be formed as a conformal film structure in which one electrolytic plating layer covers another electrolytic plating layer, or it may be formed as a shape in which one electrolytic plating layer is only stacked on one surface of another electrolytic plating layer. The seed layer of the first coil pattern 310 and the seed layer of the via 330 may be formed integrally so that no boundary is formed between them, but the present disclosure is not limited thereto. The electrolytic plating layer of the first coil pattern 310 and the electrolytic plating layer of the via 330 may also be formed integrally so that no boundary is formed between them, but the present disclosure is not limited thereto.

[0056] Each of the coil patterns 310 and 320 and the via 330 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), molybdenum (Mo), or alloys thereof, but this disclosure is not limited thereto.

[0057] External electrodes 400 and 500 may be disposed on the first surface 101 of the body 100. The first surface 101 of the body 100 may be the lower surface, such that the coil assembly according to this example embodiment may be a coil assembly having an electrode structure provided on the lower surface.

[0058] The external electrodes 400 and 500 may include a first external electrode 400 disposed on a first surface 101 and a third surface 103 of the body 100, and a second external electrode 500 disposed on a first surface 101 and a fourth surface 104 of the body 100.

[0059] The first external electrode 400 may be disposed on the third surface 103 of the main body 100 and may be connected to one end of the first coil pattern 310. The second external electrode 500 may be disposed on the fourth surface 104 of the main body 100 and may be connected to one end of the second coil pattern 320. The first external electrode 400 and the second external electrode 500 may be disposed on the first surface 101 of the main body 100 and spaced apart from each other by the insulating layer 600.

[0060] Reference Figure 4 A portion of the first external electrode 400 may be positioned closer to the body in the second direction (Y direction) on the inner side relative to the first magnetic particle 11 (i.e., Figure 4 (Right side of the image). As described above, in the coil assembly according to this example embodiment, the insulating film 11F can be selectively removed only from the first magnetic particles 11 in the regions where the outer electrodes 400 and 500 are disposed. The first magnetic particles 11 with the insulating film 11F removed can be disposed on the outside of the body relative to the boundary between the first outer electrode 400 and the insulating layer 600.

[0061] As an example, external electrodes 400 and 500 may include a first layer, a second layer disposed on the first layer, and a third layer disposed on the second layer, but are not limited thereto. For example, external electrodes 400 and 500 may include a first layer and a second layer disposed on the first layer. That is, the external electrodes may have a multilayer structure. As an example, the first external electrode 400 may include: a first layer 410 comprising copper (Cu); a second layer 420 disposed on the first layer 410, the second layer 420 comprising nickel (Ni); and a third layer 430 disposed on the second layer 420, the third layer 430 comprising tin (Sn). Here, each of the first to third layers may be formed by plating, but this disclosure is not limited thereto. As another example, the first external electrode 400 may include: a first layer 410 comprising copper (Cu); and a second layer 420 disposed on the first layer 410, and comprising nickel (Ni). Furthermore, the second external electrode 500 may have the same construction as the first external electrode 400.

[0062] The first layer of the external electrode may include copper (Cu). The first layer of the external electrode may be in contact with the first magnetic particle 11. During the plating of the first layer, the first magnetic particle 11 may be used as a seed. The insulating film 11F may be partially removed from the first magnetic particle 11, and the first magnetic particle 11 may be in contact with the first layer of the external electrode, such that the first layer can be stably formed on the first surface 101 of the body.

[0063] However, this disclosure is not limited thereto. For example, the first layer of the external electrode may be a conductive resin layer. The conductive resin layer may include a resin and a metal component dispersed in the resin. The resin (a thermosetting resin) may include an epoxy resin. The metal component may include silver (Ag) or copper (Cu). For example, in this exemplary embodiment, the conductive resin layer may be an Ag epoxy resin layer or a Cu epoxy resin layer.

[0064] The first external electrode 400 and the second external electrode 500 may be formed using conductive materials such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof, but this disclosure is not limited thereto.

[0065] The external electrodes 400 and 500 may be formed using vapor deposition (such as sputtering) and / or plating methods, but this disclosure is not limited thereto.

[0066] An insulating layer 600 may be disposed on the first surface 101 of the main body 100 and may cover the side surfaces of the outer electrodes 400 and 500.

[0067] An insulating layer 600 may be disposed on the surface of the body 100 to prevent the body 100 from being exposed to the outside of the coil assembly. Specifically, the insulating layer 600 may be disposed on the areas of the first surface 101, second surface 102, fifth surface 105, and sixth surface 106 of the body 100 where the external electrodes are not formed. The insulating layer 600 may be used as a plating resist when the external electrodes 400 and 500 are formed by plating, but this disclosure is not limited thereto.

[0068] The insulating layer 600 can be disposed on the surface of the body 100 on which the outer electrodes 400 and 500 are not formed, and can be used to electrically protect the coil assembly, reduce leakage current, and prevent plating diffusion during the formation of the outer electrodes.

[0069] The insulating layer 600 may include thermoplastic resins (such as polystyrene resins, vinyl acetate resins, polyester resins, polyethylene resins, polypropylene resins, polyamide resins, rubber resins, acrylic resins, parylene resins, etc.), thermosetting resins (such as phenolic resins, epoxy resins, polyurethane resins, melamine resins, alkyd resins, etc.), photosensitive resins, SiO2, etc. x or SiN x .

[0070] A coil insulating film IF may be disposed between the coil 300 and the body 100, and between the support member 200 and the body 100. The coil insulating film IF may be formed along the surface of the support member 200, but this disclosure is not limited thereto. The coil insulating film IF may be used to insulate the coil 300 and the body 100 from each other, and may include known insulating materials such as parylene, but this disclosure is not limited thereto. As another example, the coil insulating film IF may include insulating materials such as epoxy resin, but not parylene. The coil insulating film IF may be formed using a vapor deposition method, but this disclosure is not limited thereto. As another example, the coil insulating film IF may be formed by laminating an insulating film for forming the coil insulating film IF on the two surfaces of the support member 200 on which the coil 300 is formed, and then curing it; and the coil insulating film IF may be formed by coating an insulating paste for forming the coil insulating film IF on the two surfaces of the support member 200 on which the coil 300 is formed, and then curing it. For the reasons described above, the coil insulating film IF may be omitted in this example embodiment. In other words, when the main body 100 has sufficient resistance under the design operating current and voltage of the coil assembly 1000 according to this example embodiment, the coil insulation film IF can be omitted in this example embodiment.

[0071] 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 main body includes magnetic particles and an insulating film disposed on the surface of the magnetic particles; A coil is disposed in the main body; as well as External electrodes are disposed on the first surface of the main body. The magnetic particles include a first magnetic particle that contacts the external electrode and a second magnetic particle that does not contact the external electrode. A portion of the insulating film is in contact with the second magnetic particle and the external electrode.

2. The coil assembly of claim 1, wherein, The first magnetic particle extends to the first surface of the body, and the insulating film is not disposed on a portion of the surface of the first magnetic particle.

3. The coil assembly of claim 1, wherein, A portion of the first magnetic particle protrudes from the first surface of the body.

4. The coil assembly according to claim 1, wherein, The body has a first surface and a second surface opposite to the first surface in a first direction, and a third surface and a fourth surface connecting the first surface and the second surface to each other, the third surface and the fourth surface being opposite to each other in a second direction.

5. The coil assembly according to claim 4, wherein, Relative to the first magnetic particle, a portion of the outer electrode is positioned closer to the body on the inner side in the second direction.

6. The coil assembly according to claim 4, further comprising: An insulating layer is disposed on the first surface of the body, the insulating layer covering the side surface of the external electrode in the second direction.

7. The coil assembly according to claim 6, wherein, Relative to the insulating layer, a portion of the second magnetic particle is positioned closer to the body on the outer side in the second direction.

8. The coil assembly according to claim 6, wherein, A portion of the insulating film is disposed between the second magnetic particle and the insulating layer.

9. The coil assembly according to claim 4, wherein, The external electrode includes: a first external electrode disposed on the third surface and the first surface of the body; and a second external electrode disposed on the fourth surface and the first surface of the body.

10. The coil assembly according to claim 9, wherein, A portion of the first magnetic particle extends to the third and fourth surfaces of the body, and The portions of the first magnetic particle that extend to the third and fourth surfaces of the body have cut surfaces.

11. The coil assembly according to claim 1, wherein, The external electrode includes a first layer and a second layer disposed on the first layer, and The first layer includes at least one selected from the group consisting of copper and silver.

12. The coil assembly according to claim 11, wherein, The first layer also includes resin.

13. A coil assembly, comprising: The main body includes magnetic particles and an insulating film disposed on the surface of the magnetic particles; A coil is disposed in the main body; as well as External electrodes are disposed on the first surface of the main body. The magnetic particles include a first magnetic particle that is in contact with the external electrode and a second magnetic particle that is not in contact with the external electrode. The area on the first surface where the first magnetic particles are distributed is smaller than the area on the first surface where the external electrode is disposed.

14. The coil assembly of claim 13, wherein, A portion of the second magnetic particle is distributed on the first surface in the region where the external electrode is disposed.

15. The coil assembly of claim 13, wherein, A portion of the second magnetic particle protrudes relative to the first surface of the body.

16. The coil assembly of claim 13, wherein, The first magnetic particle extends to the first surface of the body, and the insulating film is not disposed on a portion of the surface of the first magnetic particle.

17. The coil assembly of claim 13, wherein, The external electrode includes a first layer and a second layer disposed on the first layer, and The first layer includes at least one selected from the group consisting of copper and silver.

18. The coil assembly of claim 16, wherein, The portion of the surface of the first magnetic particle that is not covered with the insulating film contacts the external electrode.

19. The coil assembly of claim 13, wherein, The first magnetic particle extends to the first surface of the body, and the insulating film is not disposed on the surface of the portion of the first magnetic particle that extends to the outside of the first surface of the body.

Images