Coil assembly

Abstract

A coil assembly is provided. The coil assembly includes a main body, a support substrate disposed in the main body, a coil part disposed on the support substrate and including first, second, third, and fourth coil layers spaced apart from each other, and first and second outer electrodes disposed to be spaced apart from each other on the main body and connected to the first and fourth coil layers, respectively. Each of the second and third coil layers includes a first metal layer disposed on the support substrate, and a second metal layer disposed on the first metal layer to cover a side surface of the first metal layer and contact the support substrate. The second coil layer has a first bridge pattern exposed to a first side surface of two side surfaces of the main body opposite to each other. The third coil layer has a second bridge pattern exposed to a second side surface of the two side surfaces of the main body.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0162898, filed on November 27, 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] As electronic devices achieve higher performance and become smaller, the coil components used in these devices have been miniaturized. However, the characteristics of individual coil components, such as inductance, need to be at the same or higher level compared to electronic components based on existing technologies. Summary of the Invention

[0005] One aspect of this disclosure provides a coil assembly comprising multiple coil layers. In the coil assembly, the total volume of the coil layers, which serve as conductors, can be increased.

[0006] According to one aspect of this disclosure, a coil assembly includes: a body; a support substrate disposed in the body; a coil portion disposed on the support substrate and including a first coil layer, a second coil layer, a third coil layer, and a fourth coil layer spaced apart from each other; and a first external electrode and a second external electrode disposed on the body, spaced apart from each other, and respectively connected to the first coil layer and the fourth coil layer. Each of the second coil layer and the third coil layer includes: a first metal layer disposed on the support substrate; and a second metal layer disposed on the first metal layer to cover a side surface of the first metal layer and contact the support substrate. The second coil layer has a first bridging pattern exposed on a first side surface of two opposing side surfaces of the body. The third coil layer has a second bridging pattern exposed on a second side surface of the two side surfaces of the body.

[0007] According to another aspect of this disclosure, a coil assembly includes: a body including a first surface and a second surface opposed to each other in a length direction, a third surface and a fourth surface connected to the first surface and the second surface and opposed to each other in a width direction, and a fifth surface and a sixth surface connected to the first surface and the fourth surface and opposed to each other in a thickness direction; a support substrate disposed in the body; a coil portion disposed on the support substrate and including a first coil layer, a second coil layer, a third coil layer, and a fourth coil layer spaced apart from each other in the thickness direction; and a first external electrode and a second external electrode disposed on the body, spaced apart from each other, and respectively connected to the first coil layer and the fourth coil layer. Each of the second coil layer and the third coil layer includes a plurality of metal layers stacked on top of each other. The outer ends of the first coil layer and the fourth coil layer are exposed to the first surface and the second surface of the body in the length direction, respectively. The second coil layer has a first bridging pattern extending from the outer ends of the second coil layer, the first bridging pattern being exposed through the third surface of the body in the width direction. The third coil layer has a second bridging pattern extending from the outer ends of the third coil layer, the second bridging pattern being exposed through the fourth surface of the body in the width direction. Attached Figure Description

[0008] The above and other aspects, features and advantages of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings.

[0009] Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment of the present disclosure.

[0010] Figure 2 yes Figure 1 A schematic exploded view of the coil section.

[0011] Figure 3 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0012] Figure 4 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0013] Figure 5 yes Figure 4 A magnified view of part of the letter "A".

[0014] Figure 6 yes Figure 4 A magnified view of part of the "C". Detailed Implementation

[0015] The terminology used in the description of this disclosure is for describing particular embodiments and is not intended to limit the disclosure. Unless otherwise stated, singular terms include plural forms. Terms such as “comprising,” “including,” “constructed as,” etc., in the description of this disclosure are used to indicate the presence of features, quantities, steps, operations, elements, components, or combinations thereof, but do not preclude the possibility of combining or adding one or more additional features, quantities, steps, operations, elements, components, or combinations thereof. Furthermore, terms such as “set on,” “located on,” etc., may indicate that an element is located above or below an object, and do not necessarily mean that the element is above the object relative to the direction of gravity.

[0016] Terms such as “integrated into” or “combined into” not only indicate that elements are in direct and physical contact with each other, but also include a configuration in which another element is located between the elements such that the element is also in contact with the other element.

[0017] For ease of description, the dimensions and thicknesses of the elements shown in the accompanying drawings are shown as examples, and this disclosure is not limited thereto.

[0018] 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.

[0019] In the following, a coil assembly according to exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Referring to the drawings, the same or corresponding components may be designated by the same reference numerals, and repeated descriptions will be omitted.

[0020] 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.

[0021] In other words, in electronic devices, coil assemblies can be used as power inductors, high-frequency inductors, general-purpose ferrite beads, high-frequency ferrite beads (e.g., suitable for the GHz band), common-mode filters, etc.

[0022] Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment. Figure 2 yes Figure 1 A schematic exploded view of the coil section. Figure 3 It is along Figure 1 The cross-sectional view taken by line I-I', and Figure 4 It is along Figure 1 The cross-sectional view taken from line II-II'. Figure 5 yes Figure 4 A magnified view of part of the "A", and Figure 6 yes Figure 4 A magnified view of part of the "C". In Figure 1The internal structure of the coil section is shown in the image, omitting the supporting substrate and insulating layer.

[0023] Reference Figures 1 to 6 According to an exemplary embodiment, the coil assembly 1000 may include a body 100, a support substrate 210, a coil portion 300, insulating layers 221 and 222, external electrodes 400 and 500, and an insulating layer IF. The coil assembly 1000 may also include a surface insulating layer 600.

[0024] The main body 100 can form the appearance of the coil assembly 1000, and the coil portion 300 can be embedded in the main body 100.

[0025] The main body 100 can be formed into a hexahedral shape as a whole.

[0026] In the following description, exemplary embodiments will be described with the body 100 having a hexahedral shape. However, such a description does not exclude the inclusion of coil assemblies formed with bodies having a shape other than a hexahedral shape from the scope of this disclosure.

[0027] Reference Figure 1 , Figure 3 and Figure 4 The main body 100 has a first surface 101 and a second surface 102 that are opposite each other in the length direction L, a third surface 103 and a fourth surface 104 that are opposite each other in the width direction W, and a fifth surface 105 and a sixth surface 106 that are opposite each other in the thickness direction T. Each of the first surface 101, the second surface 102, the third surface 103, and the fourth surface 104 of the main body 100 may correspond to a wall surface of the main body 100 that connects the fifth surface 105 and the sixth surface 106 of the main body 100. In the following, 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, respectively, and 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, respectively. In addition, 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. When the coil assembly 1000 according to this embodiment is mounted on a mounting plate such as a printed circuit board (PCB), a surface 106 of the body 100 may be configured as a mounting surface facing the mounting plate for mounting on the mounting plate.

[0028] As an example, the body 100 may be formed in such a way that the coil assembly 1000, including the external electrodes 400 and 500, which will be described later, and the surface insulation 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.

[0029] As an example, the length of the coil assembly 1000 can refer to the maximum length of a plurality of line segments connecting 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 of the coil assembly 1000, based on an optical microscope or scanning electron microscope (SEM) image of the cross-section of the coil assembly 1000 in the width direction W at the center portion of the body 100, in the length-thickness direction L. Alternatively, the length of the coil assembly 1000 can refer to the minimum length of a plurality of line segments connecting 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 of the coil assembly 1000, as shown in the cross-sectional image. Alternatively, the length of the coil assembly 1000 can refer to the arithmetic mean of the lengths of at least two line segments connecting 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 of the coil assembly 1000, as shown in the cross-sectional image.

[0030] The thickness of the coil assembly 1000 can refer to: the maximum length of a plurality of line segments 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, based on an optical microscope or scanning electron microscope (SEM) image of the cross-section of the coil assembly 1000 at the central portion of the body 100 in the width direction W and in the length-thickness direction LT. Alternatively, the thickness of the coil assembly 1000 can refer to the minimum length of a plurality of line segments 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, as shown in the cross-sectional image. Alternatively, the thickness of the coil assembly 1000 can refer to the arithmetic mean of the lengths of at least two line segments 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, as shown in the cross-sectional image.

[0031] The width of the coil assembly 1000 can refer to: the maximum length of a plurality of line segments 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, based on an optical microscope or scanning electron microscope (SEM) image of the coil assembly 1000 in the cross-section of the body 100 in the thickness direction T and in the length-width direction LW. Alternatively, the width of the coil assembly 1000 can refer to the minimum length of a plurality of line segments 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, as shown in the cross-sectional image. Alternatively, the width of the coil assembly 1000 can refer to the arithmetic mean of the lengths of at least two line segments 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, as shown in the cross-sectional image.

[0032] The length, width, and thickness of the coil assembly 1000 can each be measured using a micrometer. In this method, the measurement is performed by zeroing a micrometer (instrument) with metrological repeatability and reproducibility (R&R), inserting the coil assembly 1000 between the tips of the micrometer, and rotating the measuring rod of the micrometer. When measuring the length of the coil assembly 1000 using this method, the length can refer to a single measurement or the arithmetic mean of multiple measurements. This can be applied equivalently to the width and thickness of the coil assembly 1000.

[0033] The body 100 may include a magnetic material and a resin. Specifically, the body 100 may be formed by laminating at least one magnetic composite sheet in which the magnetic material is dispersed in a resin. However, the body 100 may have a structure other than that in which the magnetic material is dispersed in a resin. For example, the body 100 may be formed using a magnetic material (such as ferrite) or a non-magnetic material.

[0034] Magnetic materials can be ferrite powder particles or magnetic metal powder particles.

[0035] Examples of ferrite powder particles may include at least one of spinel-type ferrites (such as Mg-Zn-based ferrites, Mn-Zn-based ferrites, Mn-Mg-based ferrites, Cu-Zn-based ferrites, Mg-Mn-Sr-based ferrites, Ni-Zn-based ferrites, etc.), hexagonal ferrites (such as Ba-Zn-based ferrites, Ba-Mg-based ferrites, Ba-Ni-based ferrites, Ba-Co-based ferrites, Ba-Ni-Co-based ferrites, etc.), garnet-type ferrites (such as Y-based ferrites, etc.), and Li-based ferrites.

[0036] Magnetic metal powder particles 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 powder particles may be at least one selected from pure iron powder, Fe-Si based alloy powder, Fe-Si-Al based alloy powder, Fe-Ni based alloy powder, Fe-Ni-Mo based alloy powder, Fe-Ni-Mo-Cu based alloy powder, Fe-Co based alloy powder, Fe-Ni-Co based alloy powder, Fe-Cr based alloy powder, Fe-Cr-Si based alloy powder, Fe-Si-Cu-Nb based alloy powder, Fe-Ni-Cr based alloy powder, and Fe-Cr-Al based alloy powder.

[0037] Magnetic metal powder particles can be amorphous or crystalline. For example, magnetic metal powder particles can be Fe-Si-B-Cr based amorphous alloy powder, but are not limited to this.

[0038] Each of the magnetic metal powder particles may have an average diameter of about 0.1 μm to 30 μm, but is not limited thereto.

[0039] Body 100 may include two or more types of magnetic metal powder particles dispersed in a resin. The term "different types of magnetic powder particles" means that the magnetic powder particles dispersed in the resin are distinguished from each other by at least one of average diameter, composition, crystallinity, and shape.

[0040] Resins may include, but are not limited to, single or combined forms of epoxy resins, polyimides, liquid crystal polymers, etc.

[0041] The body 100 may include a core 110 passing through the coil portion 300, which will be described later. The core 110 may be formed by filling the through-hole of the coil portion 300 with a magnetic composite sheet, but this disclosure is not limited thereto.

[0042] The coil portion 300 may be disposed in the main body 100 to exhibit the characteristics of the coil assembly 1000. For example, when the coil assembly 1000 of this embodiment is used as a power inductor, the coil portion 300 may be connected to each of the first external electrode 400 and the second external electrode 500, which will be described later, and may store the electric field as a magnetic field to maintain the output voltage for stabilizing the power of the electronic device.

[0043] The support substrate 210 can be disposed in the main body 100 and can support the coil section 300, which will be described later.

[0044] The support substrate 210 may include an insulating material, such as a thermosetting insulating resin like epoxy resin, a thermoplastic insulating resin like polyimide, or a photosensitive insulating resin. Alternatively, the support substrate 210 may include an insulating material in which a reinforcing material such as glass fiber or inorganic filler is impregnated with an insulating resin. For example, the support substrate 210 may include insulating materials such as copper-clad laminate (CCL), prepreg, Ajinomoto build-up film (ABF), FR-4, bismaleimide triazine (BT) film, photosensitive dielectric (PID) film, etc., but is not limited thereto.

[0045] The inorganic filler may be at least one selected from the group consisting of silicon dioxide (SiO2), aluminum oxide (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc, mud, 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).

[0046] When the support substrate 210 is formed using an insulating material including reinforcing material, the support substrate 210 can provide higher rigidity. When the support substrate 210 is formed using an insulating material that does not include glass fiber, the support substrate 210 facilitates thinning of the entire coil portion 300 to reduce the thickness of the assembly. When the support substrate 210 is formed using an insulating material containing photosensitive insulating resin, the number of processes used to form the coil portion 300 can be reduced. Therefore, this can be advantageous in terms of reducing production costs, and fine holes can be machined.

[0047] The coil portion 300 may be disposed on the support substrate 210 and may include a first coil layer 311, a second coil layer 312, a third coil layer 313, and a fourth coil layer 314 spaced apart from each other. Specifically, based on Figure 2 and Figure 3In each of the following directions, the coil portion 300 may include: a first coil layer 311, disposed at the uppermost position to connect to the first external electrode 400, which will be described later; a second coil layer 312, disposed below the first coil layer 311; a third coil layer 313, disposed below the second coil layer 312; and a fourth coil layer 314, disposed below the third coil layer 313 to be disposed at the lowermost position and connected to the second external electrode 500, which will be described later. Each of the first coil layer 311, the second coil layer 312, the third coil layer 313, and the fourth coil layer 314 may have a planar spiral shape in which at least one turn is formed around the core 110. Hereinafter, the case where the coil portion 300 applied to this embodiment includes a total of four coil layers 311, 312, 313, and 314 will be used as an example, but the scope of this embodiment is not limited thereto.

[0048] based on Figure 3 and Figure 4 The second coil layer 312 may be configured to contact the upper surface of the support substrate 210. The third coil layer 313 may be configured to contact the lower surface of the support substrate 210. The first coil layer 311 may be disposed above the second coil layer 312. The fourth coil layer 314 may be disposed below the third coil layer 313. The first insulating layer 221, which will be described later, may be disposed on the upper surface of the support substrate 210 to cover the second coil layer 312. The first coil layer 311 may be configured to contact the first insulating layer 221. The second insulating layer 222, which will be described later, may be disposed on the lower surface of the support substrate 210 to cover the third coil layer 313. The fourth coil layer 314 may be configured to contact the second insulating layer 222. The outer end portion 311-1 of the first coil layer 311 may be exposed on the first surface 101 of the body 100 to contact and connect with the first external electrode 400. The outer end portion 314-1 of the fourth coil layer 314 may be exposed on the second surface 102 of the body 100 to contact and connect with the second external electrode 500.

[0049] The coil portion 300 may further include: a first via 321, passing through a first insulating layer 221 (described later) to connect the inner end portion 311-2 of the first coil layer 311 to the inner end portion 312-2 of the second coil layer 312; a second via 322, passing through a support substrate 210 to connect the outer end portion 312-1 of the second coil layer 312 to the outer end portion 313-1 of the third coil layer 313; and a third via 323, passing through the second insulating layer 222 (described later) to connect the inner end portion 313-2 of the third coil layer 313 to the inner end portion 314-2 of the fourth coil layer 314. Each end of the first coil layer 311-2 connected to the first via 321, the inner end of the first coil layer 311, the inner end of the second coil layer 312-2 connected to the first via 321, the outer end of the second coil layer 312-1 connected to the second via 322, the outer end of the third coil layer 313-1 connected to the second via 322, and the inner end of the third coil layer 313-2 connected to the third via 323, and the inner end of the fourth coil layer 314-2 connected to the third via 323, can be a via pad. The via pad is formed with a diameter larger than the width of each turn in the coil layers 311, 312, 313, and 314 to ensure reliable connection with the vias 321, 322, and 323. Therefore, the coil portion 300 can be used as a single coil connected in series between the first external electrode 400 and the second external electrode 500, which will be described later.

[0050] The first coil layer 311 and the fourth coil layer 314 may include a conductive thin film (or conductive membrane) disposed on an insulating layer, a third metal layer disposed on the conductive thin film, and a fourth metal layer disposed on the third metal layer. (Refer to...) Figure 5 As an example, the first coil layer 311 may include: a conductive film 311A ​​configured to contact the first insulating layer 221; a third metal layer 311B configured to contact the conductive film 311A ​​and expose the side surface of the conductive film 311A ​​while being spaced apart from the first insulating layer 221; and a fourth metal layer 311C disposed on the third metal layer 311B to cover the side surface of the third metal layer 311B and to contact the first insulating layer 221. The first coil layer 311 may be formed in the following manner: based on Figure 5In the direction of the first insulating layer 221, a thin film for forming a conductive thin film is formed on the entire upper surface of the first insulating layer 221 (including the inner wall of the via formed in the first insulating layer 221, such that the first via 321 is provided). A photoresist having an opening corresponding to the third metal layer 311B is formed on the thin film. The opening of the photoresist is filled with the third metal layer 311B. The photoresist is removed. A specific area of ​​the thin film exposed to the outside due to the absence of a third metal layer 311B is removed to form a conductive thin film 311A. Lead-in wire plating is performed on the exposed surfaces of the conductive thin film 311A ​​and the third metal layer 311B to form a fourth metal layer 311C. Each of the third metal layer 311B and the fourth metal layer 311C may be an electroplated layer, and the conductive thin film 311A ​​may be an electroless layer or a sputtered layer, but this disclosure is not limited thereto. The conductive thin film 311A ​​may include at least one of molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), and copper (Cu), and may be formed having a structure including at least one layer. Each of the third metal layer 311B and the fourth metal layer 311C may include at least one of molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), and copper (Cu), and may be formed having a structure including at least one layer. As an example, unlike the third metal layer 311B, the fourth metal layer 311C may be deposited and grown without the restriction of a resist agent, and may be an isotropic plating layer. In this case, the thickness of the fourth metal layer 311C grown from the side surface of the conductive thin film 311A, the side surface of the third metal layer 311B, and the upper surface of the third metal layer 311B may be substantially the same. For example, as... Figure 5 As shown, the dimension d1 in the thickness direction T of the region disposed on the upper surface of the third metal layer 311B in the fourth metal layer 311C can be substantially the same as the dimension d2 in the width direction W of the region disposed on the side surface of the third metal layer 311B in the fourth metal layer 311C. As another example, unlike the third metal layer 311B, the fourth metal layer 311C can be deposited and grown without the restriction of a resist agent, and can be an anisotropic coating. In this case, the thickness of the fourth metal layer 311C grown from the upper surface of the third metal layer 311B can be significantly greater than the thickness of the fourth metal layer 311C grown from the side surface of the third metal layer 311B. For example, with... Figure 5As shown, the dimension d1 of the region disposed on the upper surface of the third metal layer 311B in the fourth metal layer 311C in the thickness direction T can be significantly larger than the dimension d2 of the region disposed on the side surface of the third metal layer 311B in the width direction W. As another example, the fourth metal layer 311C may have a structure including at least one of the aforementioned isotropic plating layers and at least one of the aforementioned anisotropic plating layers. With the insulating layers 221 and 222 respectively formed on the two surfaces of the support substrate 210, the processes for forming the first coil layer 311 and the fourth coil layer 314 can be performed simultaneously on the upper surface side and the lower surface side of the support substrate 210. Therefore, although not shown in the figures, the fourth coil layer 314 may also have the aforementioned structure of the first coil layer 311, including the conductive thin film 311A, the third metal layer 311B, and the fourth metal layer 311C.

[0051] The second and third coil layers each include a thin-film conductive layer disposed on a support substrate, a first metal layer disposed on the thin-film conductive layer, and a second metal layer disposed on the first metal layer. (See reference...) Figure 6 As an example, the second coil layer 312 may include: a conductive film 312A configured to contact the support substrate 210; a first metal layer 312B configured to contact the conductive film 312A and expose the side surface of the conductive film 312A while being spaced apart from the support substrate 210; and a second metal layer 312C disposed on the first metal layer 312B to cover the first metal layer 312B and configured to contact the support substrate 210. The second coil layer 312 may be formed in the following manner: based on Figure 6In the direction of the first metal layer 312B, a conductive thin film is formed on the entire upper surface of the support substrate 210 (including the inner wall of the via formed in the support substrate 210, such that a second via 322 is provided). A photoresist with an opening corresponding to the first metal layer 312B is formed on the thin film. The opening of the photoresist is filled with the first metal layer 312B. The photoresist is removed. A specific area of ​​the thin film exposed to the outside due to the absence of the first metal layer 312B is removed to form a conductive thin film 312A. Lead-in wire plating is performed on the exposed surfaces of the conductive thin film 312A and the first metal layer 312B to form a second metal layer 312C. Each of the first metal layer 312B and the second metal layer 312C may be an electroplated layer, and the conductive thin film 312A may be an electroless layer or a sputtered layer, but this disclosure is not limited thereto. The conductive thin film 312A may include at least one of molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), and copper (Cu), and may be formed to have a structure including at least one layer. Each of the first metal layer 312B and the second metal layer 312C may include at least one of molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), and copper (Cu), and may be formed into a structure having at least one layer. As an example, unlike the first metal layer 312B, the second metal layer 312C may be deposited and grown without the restriction of a resist agent, and may be an isotropic plating layer. In this case, the thickness of the second metal layer 312C grown from the side surface of the conductive thin film 312A, the side surface of the first metal layer 312B, and the upper surface of the first metal layer 312B may be substantially the same. For example, as... Figure 6 As shown, the dimension d3 of the region in the second metal layer 312C disposed on the upper surface of the first metal layer 312B in the thickness direction T can be substantially the same as the dimension d4 of the region in the second metal layer 312C disposed on the side surface of the first metal layer 312B in the width direction W. As another example, unlike the first metal layer 312B, the second metal layer 312C can be deposited and grown without the restriction of a resist agent, and can be an anisotropic coating. In this case, the thickness of the second metal layer 312C grown from the upper surface of the first metal layer 312B can be significantly greater than the thickness of the second metal layer 312C grown from the side surface of the first metal layer 312B. For example, with... Figure 6 As shown, the region in the second metal layer 312C disposed on the upper surface of the first metal layer 312B has a dimension d3 in the thickness direction T that is significantly larger than the region in the second metal layer 312C disposed on the side surface of the first metal layer 312B has a dimension d4 in the width direction W. As another example, the second metal layer 312C may have a structure including at least one of the above-described isotropic coatings and at least one of the above-described anisotropic coatings.

[0052] The processes for forming the second coil layer 312 and the third coil layer 313 can be performed simultaneously on both surfaces of the support substrate 210. Therefore, the third coil layer 313 may also have a structure including a conductive thin film 313A, a first metal layer 313B, and a second metal layer 313C.

[0053] In conventional thin-film coil assemblies comprising four or more coil layers, the inner coil layer, which is not disposed on the top layer but surrounded by an insulating layer and a support substrate, can be formed by performing only pattern plating. Therefore, there are limitations in increasing the overall volume of the conductors (coils). In this embodiment, the second coil layer 312 (inner coil layer) includes a first metal layer 312B as a pattern plating layer and a second metal layer 312C as a lead-in line plating layer, and the third coil layer 313 (inner coil layer) includes a first metal layer 313B as a pattern plating layer and a second metal layer 313C as a lead-in line plating layer. Therefore, the volume of the conductors in the inner coil layer can be increased, thereby also increasing the overall volume of the conductors in the coil portion 300 within the finite-sized body 100. For this reason, component characteristics such as the component's DC resistance Rdc can be improved.

[0054] The second coil layer 312 and the third coil layer 313 may each have a first bridging pattern B1 and a second bridging pattern B2. Bridging patterns B1 and B2 may be plating lead lines for plating the first metal layer 312B and the second metal layer 312C of the second coil layer 312 and the first metal layer 313B and the second metal layer 313C of the third coil layer 313, respectively. Therefore, in a large-area substrate where multiple coils are interconnected, bridging patterns B1 and B2 may have a shape connecting to plating lead lines disposed between areas corresponding to each component, and may be cut from another adjacent individual component in a cutting process that individualizes multiple coils, and may be exposed on the surface of the body of each component. In this embodiment, the first bridging pattern B1 may contact and connect with the outer end portion 312-1 of the second coil layer 312, and the first bridging pattern B1 may extend to expose the third surface 103 of the body 100. The second bridging pattern B2 may contact and connect with the region adjacent to the fourth surface 104 side of the body 100 in the outermost turn of the third coil layer 313 (extending from the outer end portion 313-1 of the third coil layer 313), and the second bridging pattern B2 may extend to expose the fourth surface 104 of the body 100. As an example, when bridging patterns B1 and B2 are exposed together on one surface of the body 100, the plating current density may be dispersed during the plating formation of the second metal layers 312C and 313C, thereby increasing the plating time required for the plating growth of the second metal layers 312C and 313C. Furthermore, the plating current is applied from a region adjacent to one surface of the body 100 to both the second metal layer 312C of the second coil layer 312 and the second metal layer 313C of the third coil layer 313, such that the final second metal layers 312C and 313C can have a shape with the greatest thickness on one surface side of the body 100. Therefore, the second coil layer 312 and the third coil layer 313 can be generally asymmetrical with respect to the core 110. In this embodiment, since one of the bridging patterns B1 and B2 is exposed on one of the third surface 103 and the fourth surface 104 of the body 100, and the other bridging pattern is exposed on the other surface of the third surface 103 and the fourth surface 104, the second metal layer 312C of the second coil layer 312 and the second metal layer 313C of the third coil layer 313 can be formed more easily and uniformly.

[0055] Each of the first coil layer 311, the second coil layer 312, the third coil layer 313, and the fourth coil layer 314, as well as the first via 321, the second via 322, and the third via 323, 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.

[0056] Insulating layers 221 and 222 can be formed using materials including at least one of thermosetting insulating resins such as epoxy resins, thermoplastic insulating resins such as polyimide resins, and photosensitive insulating resins, or insulating materials in which reinforcing materials such as glass fibers or inorganic fillers are impregnated with insulating resins. As an example, insulating layers 221 and 222 may include, but are not limited to, film-type insulating materials such as prepregs, Ajinomoto Build-up Films (ABF), and photosensitive dielectric (PID) films. Insulating layers 221 and 222 can be formed by coating a liquid insulating resin and curing the coated liquid insulating resin.

[0057] An insulating layer IF may be disposed between the coil portion 300 and the body 100, and between the support substrate 210 and the body 100. The insulating layer IF may be formed along the surface of the support substrate 210 on which the first coil layer 311, the second coil layer 312, the third coil layer 313, and the fourth coil layer 314, as well as the insulating layers 221 and 222, are formed. A portion of the insulating layer IF may be disposed between adjacent turns of the first coil layer 311 and / or the fourth coil layer 314. The insulating layer IF may be configured to insulate the coil portion 300 and the body 100 from each other, and may include, but is not limited to, known insulating materials (such as parylene). As another example, the insulating layer IF may include an insulating material such as epoxy resin (instead of parylene). The insulating layer IF may be formed by vapor deposition, but this disclosure is not limited thereto. As another example, the insulating layer IF can be formed by laminating an insulating film for forming the insulating layer IF onto the two surfaces of the support substrate 210 on which the coil portion 300 and the insulating layers 221 and 222 are formed, and then curing the laminated insulating film. Alternatively, the insulating layer IF can be formed by applying an insulating paste for forming the insulating layer IF onto the two surfaces of the support substrate 210 on which the coil portion 300 and the insulating layers 221 and 222 are formed, and then curing the applied insulating paste.

[0058] External electrodes 400 and 500 may be spaced apart from each other on the body 100 and may be connected to the coil portion 300. In this embodiment, external electrodes 400 and 500 include first layers 410 and 510 and second layers 420 and 520 disposed on at least a portion of the first layers 410 and 510. The first layers 410 and 510 of external electrodes 400 and 500 may include: pad portions 412 and 512, spaced apart from each other on the sixth surface 106 of the body 100; and connecting portions 411 and 511, respectively disposed on the first surface 101 and the second surface 102 of the body 100. Specifically, the first layer 410 of the first external electrode 400 may include: a first connecting portion 411 disposed on the first surface 101 of the body 100 to contact the outer end portion 311-1 of the first coil layer 311 exposed to the first surface 101 of the body 100; and a first pad portion 412 extending from the first connecting portion 411 to the sixth surface 106 of the body 100. The first layer 510 of the second external electrode 500 may include: a second connecting portion 511 disposed on the second surface 102 of the body 100 to contact the outer end portion 314-1 of the fourth coil layer 314 exposed to the second surface 102 of the body 100; and a second pad portion 512 extending from the second connecting portion 511 to the sixth surface 106 of the body 100. The first pad portion 412 and the second pad portion 512 may be configured to be spaced apart from each other on the sixth surface 106 of the body 100. The first connecting portion 411 and the first pad portion 412 can be formed together in the same process to become one with each other without forming a boundary between them, and the second connecting portion 511 and the second pad portion 512 can be formed together in the same process to become one with each other without forming a boundary between them, but this disclosure is not limited thereto.

[0059] The first layers 410 and 510 may be formed by vapor deposition (such as sputtering) or plating. Alternatively, the first layers 410 and 510 may be formed by coating a conductive paste comprising a conductive powder (containing at least one of copper (Cu) and silver (Ag)) and an insulating resin, and then curing the coated conductive paste. As an example, each of the first layers 410 and 510 may be a copper (Cu) plating, but this disclosure is not limited thereto.

[0060] Second layers 420 and 520 may be disposed on at least a portion of first layers 410 and 510. Second layers 420 and 520 may be formed by vapor deposition (such as sputtering) or plating. As an example, each of the second layers 420 and 520 may be formed as a structure having two or more layers including a nickel (Ni) plating and a tin (Sn) plating, but this disclosure is not limited thereto. Figure 3 In the illustration, the second layers 420 and 520 are shown as being disposed only on the pad portions 412 and 512. However, since this is merely an example, this disclosure is not limited thereto.

[0061] Each of the external electrodes 400 and 500 may be formed using a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or alloys thereof, but this disclosure is not limited thereto.

[0062] exist Figure 1 In the diagram, each of the first layers 410 and 510 of the outer electrodes 400 and 500 is shown as having an "L" shape. However, this is only an example, and the overall shape of each of the first layers 410 and 510 may be appropriately changed to a "[" shape, etc., and thus the overall shape of each of the outer electrodes 400 and 500 may be appropriately changed to a "[" shape, etc.

[0063] Surface insulating layers 610 and 620 may surround the first surface 101, second surface 102, third surface 103, fourth surface 104, fifth surface 105, and sixth surface 106 of the body 100, excluding the areas where the external electrodes 400 and 500 are formed. Surface insulating layers 610 and 620 may be formed with a multilayer structure. In this embodiment, surface insulating layers 610 and 620 may include: a first surface insulating layer 610 disposed in the areas of the first surface 101, second surface 102, third surface 103, fourth surface 104, fifth surface 105, and sixth surface 106 excluding the areas where the first layers 410 and 510 will form the external electrodes 400 and 500; and a second surface insulating layer 620 disposed on the connecting portions 411 and 511 of the first layers 410 and 510 to cover the connecting portions 411 and 511. The second surface insulating layer 620 may be formed integrally with each other on the first surface 101, second surface 102, third surface 103, fourth surface 104 and fifth surface 105 of the body 100, but the present disclosure is not limited thereto. Surface insulating layers 610 and 620 may be used as plating resists during the plating formation of the external electrodes 400 and 500, but the present disclosure is not limited thereto.

[0064] Each of the surface insulating layers 610 and 620 may include a thermoplastic resin (such as polystyrene resin, vinyl acetate resin, polyester resin, polyethylene resin, polypropylene resin, polyamide resin, rubber resin, or acrylic resin), a thermosetting resin (such as phenolic resin, epoxy resin, urethane resin, melamine resin, or alkyd resin), a photosensitive resin, parylene, SiO2, etc. x or SiN x .

[0065] Each of surface insulating layers 610 and 620 may have an adhesive function. For example, when the first surface insulating layer 610 is formed using an insulating film, the insulating film may include an adhesive component to adhere to the surface of the body 100. In this case, an additional adhesive layer may be formed on one surface of the first surface insulating layer 610. However, when surface insulating layers 610 and 620 are formed using an insulating film in a semi-cured state (stage B), it is not necessary to form an additional adhesive layer on one surface of surface insulating layers 610 and 620.

[0066] The surface insulating layers 610 and 620 can be formed by coating a liquid insulating resin onto the surface of the body 100, stacking an insulating film on the surface of the body 100, or forming an insulating resin on the surface of the body 100 using vapor deposition. The insulating film can be a dry film (DF) containing a photosensitive insulating resin, an Ajinomoto Build-up Film (ABF) not containing a photosensitive insulating resin, or a polyimide film not containing a photosensitive insulating resin.

[0067] The total thickness of surface insulating layers 610 and 620 can range from 10 nm to 100 μm. When the thickness of surface insulating layers 610 and 620 is less than 10 nm, the characteristics of the coil assembly (such as Q factor, breakdown voltage, self-resonant frequency (SRF)) may be degraded. Conversely, when the thickness of surface insulating layers 610 and 620 is greater than 100 μm, the total length, width, and thickness of the coil assembly may increase, making thinning difficult.

[0068] So far, a description has been provided assuming that the coil section 300 includes four coil layers 311, 312, 313, and 314. However, this is merely an example, and the case where the coil section 300 includes five or more coil layers falls within the scope of this embodiment. As an example, when the coil section 300 includes six coil layers, the inner ends of the first and second coil layers are connected via a first via, the outer ends of the second and third coil layers are connected via a second via, the inner ends of the third and fourth coil layers are connected via a third via, the outer ends of the fourth and fifth coil layers are connected via a fourth via, and the inner ends of the fifth and sixth coil layers are connected via a fifth via. The outer ends of the first and sixth coil layers are exposed on the surface of the body 100 to contact the first and second external electrodes. The third via passes through the support substrate to connect the third and fourth coil layers to each other. Each of the first, second, fourth, and fifth vias passes through an insulating layer disposed on the support substrate.

[0069] As described above, in a coil assembly that includes multiple coil layers, the total volume of the coil layers and conductors can be increased.

[0070] Although exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and changes may be made without departing from the scope of this disclosure as defined by the appended claims.

Claims

1. A coil assembly, comprising: main body; A support substrate is disposed in the main body; The coil section is disposed on the support substrate and includes a first coil layer, a second coil layer, a third coil layer and a fourth coil layer spaced apart from each other; as well as The first and second external electrodes are arranged to be spaced apart from each other on the main body and respectively connected to the first coil layer and the fourth coil layer. Each of the second coil layer and the third coil layer includes: a first metal layer disposed on the supporting substrate; and a second metal layer disposed on the first metal layer to cover the side surface of the first metal layer and to contact the supporting substrate. The second coil layer has a first bridging pattern, which is exposed on a first side surface of two opposing side surfaces of the body. The third coil layer has a second bridging pattern, which is exposed on a second side surface of the two side surfaces of the body. Each of the second and third coil layers further includes via pads disposed at its inner and outer ends, and The first bridging pattern contacts and connects with the via pad disposed on the outer end of the second coil layer.

2. The coil assembly as claimed in claim 1, wherein, The coil portion further includes a second through-hole that passes through the support substrate to connect the outer end of the second coil layer to the outer end of the third coil layer.

3. The coil assembly as claimed in claim 1, wherein, The second bridging pattern contacts and connects to the outermost turn of the third coil layer, and the outermost turn of the third coil layer is connected to the via pad disposed on the outer end of the third coil layer.

4. The coil assembly as claimed in claim 1, wherein, In each of the second and third coil layers, the thickness of the region of the second metal layer disposed on the upper surface of the first metal layer is the same as the thickness of the region of the second metal layer disposed on the side surface of the first metal layer.

5. The coil assembly as claimed in claim 1, wherein, In each of the second and third coil layers, the thickness of the region of the second metal layer disposed on the upper surface of the first metal layer is greater than the thickness of the region of the second metal layer disposed on the side surface of the first metal layer.

6. The coil assembly as claimed in claim 1, wherein, Each of the second coil layer and the third coil layer further includes a conductive film disposed between the support substrate and the first metal layer.

7. The coil assembly of claim 6, wherein, In each of the second and third coil layers, the first metal layer exposes the side surface of the conductive film and is spaced apart from the supporting substrate.

8. The coil assembly as claimed in claim 1, wherein, The second coil layer and the third coil layer are configured to contact the first and second surfaces of the supporting substrate, respectively, which are opposite to each other. The first coil layer and the fourth coil layer are respectively spaced apart from the first surface and the second surface of the supporting substrate, and The coil assembly further includes a first insulating layer and a second insulating layer, the first insulating layer being disposed between the first surface of the support substrate and the first coil layer, and the second insulating layer being disposed between the second surface of the support substrate and the fourth coil layer.

9. The coil assembly of claim 8, wherein, Each of the first coil layer and the fourth coil layer includes: a third metal layer disposed on a corresponding insulating layer of the first insulating layer and the second insulating layer; and a fourth metal layer disposed on the third metal layer to cover a side surface of the third metal layer and to contact the corresponding insulating layer of the first insulating layer and the second insulating layer.

10. The coil assembly of claim 8, wherein, The first coil layer includes an outer end portion, the outer end portion of the first coil layer being exposed to a first end surface of one of the two end surfaces of the body that connect the two side surfaces of the body to each other, and The fourth coil layer includes an outer end portion, which is exposed on the second end surface of the two end surfaces of the body.

11. A coil assembly, comprising: The main body includes a first surface and a second surface that are opposite to each other in the length direction, a third surface and a fourth surface that connect the first surface and the second surface and are opposite to each other in the width direction, and a fifth surface and a sixth surface that connect the first surface to the fourth surface and are opposite to each other in the thickness direction. A support substrate is disposed in the main body; The coil section is disposed on the support substrate and includes a first coil layer, a second coil layer, a third coil layer and a fourth coil layer spaced apart from each other in the thickness direction; as well as The first and second external electrodes are arranged to be spaced apart from each other on the main body and respectively connected to the first coil layer and the fourth coil layer. Each of the second and third coil layers comprises multiple metal layers stacked on top of each other. The outer ends of the first coil layer and the fourth coil layer are exposed to the first and second surfaces of the body, respectively, along the length direction. The second coil layer has a first bridging pattern extending from the outer end of the second coil layer, the first bridging pattern being exposed through the third surface of the body in the width direction. The third coil layer has a second bridging pattern extending from the outer end of the third coil layer, the second bridging pattern being exposed through the fourth surface of the body in the width direction. The second coil layer and the third coil layer are disposed on the first and second surfaces of the supporting substrate, which are opposite to each other. The first coil layer and the fourth coil layer are respectively disposed on the second coil layer and the third coil layer, and The first insulating layer and the second insulating layer are respectively disposed on the first surface and the second surface of the supporting substrate, and respectively cover the second coil layer and the third coil layer.

12. The coil assembly of claim 11, wherein, Each of the first external electrode and the second external electrode includes a first layer and a second layer disposed on at least a portion of the first layer.

13. The coil assembly of claim 11, wherein, Each of the second coil layer and the third coil layer includes: a first metal layer disposed on the support substrate; and a second metal layer disposed on the first metal layer to cover the side surface of the first metal layer and to contact the support substrate.

14. The coil assembly of claim 13, wherein, Each of the first coil layer and the fourth coil layer includes: a third metal layer disposed on a corresponding insulating layer in the first insulating layer and the second insulating layer; and a fourth metal layer disposed on the third metal layer to cover a side surface of the third metal layer and to contact the corresponding insulating layer in the first insulating layer and the second insulating layer.

15. The coil assembly of claim 14, wherein, In each of the second and third coil layers, the thickness of the region of the second metal layer disposed on the upper surface of the first metal layer is the same as the thickness of the region of the second metal layer disposed on the side surface of the first metal layer, and In each of the first coil layer and the fourth coil layer, the thickness of the region of the fourth metal layer disposed on the upper surface of the third metal layer is the same as the thickness of the region of the fourth metal layer disposed on the side surface of the third metal layer.

16. The coil assembly of claim 14, wherein, In each of the second and third coil layers, the thickness of the region of the second metal layer disposed on the upper surface of the first metal layer is greater than the thickness of the region of the second metal layer disposed on the side surface of the first metal layer. In each of the first coil layer and the fourth coil layer, the thickness of the region of the fourth metal layer disposed on the upper surface of the third metal layer is greater than the thickness of the region of the fourth metal layer disposed on the side surface of the third metal layer.

17. The coil assembly of claim 14, wherein, Each of the second and third coil layers further includes a conductive film disposed between the support substrate and the first metal layer, and The first coil layer further includes a conductive film disposed in contact with the first insulating layer and between the first insulating layer and the third metal layer of the first coil layer, and the fourth coil layer further includes a conductive film disposed in contact with the second insulating layer and between the second insulating layer and the third metal layer of the fourth coil layer.

18. The coil assembly of claim 11, further comprising a third insulating layer disposed between the coil portion and the body, and between the support substrate and the body. in, A portion of the third insulating layer is disposed between adjacent turns of the first coil layer and / or the fourth coil layer.

19. A coil assembly, comprising: The main body includes a first surface and a second surface that are opposite to each other in the length direction, a third surface and a fourth surface that connect the first surface and the second surface and are opposite to each other in the width direction, and a fifth surface and a sixth surface that connect the first surface to the fourth surface and are opposite to each other in the thickness direction. A support substrate is disposed in the main body; The coil section is disposed on the support substrate and includes a first coil layer, a second coil layer, a third coil layer and a fourth coil layer spaced apart from each other in the thickness direction; as well as The first and second external electrodes are arranged to be spaced apart from each other on the main body and respectively connected to the first coil layer and the fourth coil layer. Each of the second and third coil layers comprises multiple metal layers stacked on top of each other. The outer ends of the first coil layer and the fourth coil layer are exposed to the first and second surfaces of the body, respectively, along the length direction. The second coil layer has a first bridging pattern extending from the outer end of the second coil layer, the first bridging pattern being exposed through the third surface of the body in the width direction. The third coil layer has a second bridging pattern extending from the outer end of the third coil layer, the second bridging pattern being exposed through the fourth surface of the body in the width direction. The coil assembly further includes a third insulating layer disposed between the coil portion and the main body, and also disposed between the support substrate and the main body. A portion of the third insulating layer is disposed between adjacent turns of the first coil layer and / or the fourth coil layer.

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