Coil assembly

Abstract

This disclosure provides a coil assembly comprising: a body having a first surface and a second surface opposed to each other in a first direction, a first side surface and a second side surface opposed to each other in a second direction, and a third side surface connecting the first side surface and the second side surface to each other; a coil disposed in the body, the coil including a lead extending to the third side surface of the body; an external electrode disposed on the third side surface of the body, the external electrode including a connection portion connected to the lead; and a first insulating layer disposed on a portion of the third side surface of the body where the connection portion is not disposed, the first insulating layer exposing the connection portion. The distance between the connection portion of the external electrode and the first side surface of the body is different from the distance between the connection portion of the external electrode and the second side surface of the body.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0188470, filed on December 17, 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 (coil assembly) can be a typical passive electronic component used in electronic devices along with resistors and capacitors.

[0004] In addition to their inherent inductance, power inductors can also exhibit a self-resonant frequency (SRF) due to undesirable parasitic elements such as capacitance. For power inductors with the same capacitance value, a higher SRF means the inductor operates at a higher frequency. In specialized applications, such as envelope tracking (ET) modulators, it is necessary to freely adjust the SRF of the power inductor to achieve a desired impedance value at a specific frequency. Summary of the Invention

[0005] One aspect of this disclosure is to provide a coil assembly that can improve the self-resonant frequency (SRF) by reducing parasitic capacitance elements while ensuring the size of the coil's hollow core.

[0006] According to one aspect of this disclosure, a coil assembly is provided, the coil assembly comprising: a body having a first surface and a second surface opposed to each other in a first direction, a first side surface and a second side surface opposed to each other in a second direction, and a third side surface connecting the first side surface and the second side surface to each other; a coil disposed in the body, the coil including a lead extending to the third side surface of the body; an external electrode disposed on the third side surface of the body, the external electrode including a connection portion connected to the lead; and a first insulating layer disposed on a portion of the third side surface of the body where the connection portion is not disposed, the first insulating layer exposing the connection portion. The distance between the connection portion of the external electrode and the first side surface of the body may be different from the distance between the connection portion of the external electrode and the second side surface of the body.

[0007] According to another aspect of this disclosure, a coil assembly is provided, the coil assembly comprising: a body having a first surface and a second surface opposite to each other in a first direction, a first side surface and a second side surface connecting the first surface and the second surface to each other, and a third side surface connecting the first side surface and the second side surface to each other, the first side surface and the second side surface being opposite to each other in a second direction; a coil disposed in the body, the coil including a lead-out extending to the third side surface of the body; a first insulating layer disposed on the third side surface of the body, the first insulating layer having a region and another region spaced apart from each other in the second direction; and an external electrode including a connection portion connected to the lead-out, the connection portion being disposed on the third side surface of the body and disposed between the one region and the other region of the first insulating layer, wherein the length of the one region in the second direction may be different from the length of the other region in the second direction.

[0008] According to this disclosure, the coil assembly can improve SRF by reducing parasitic capacitance elements while ensuring the size of the coil's hollow core. Attached Figure Description

[0009] 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 diagram of a coil assembly according to an exemplary embodiment of the present disclosure; Figure 2 yes Figure 1 Top view; Figure 3 It is along Figure 1 A cross-sectional view taken from the I-I' line; Figure 4 It is along Figure 1 A cross-sectional view taken from line II-II'; Figure 5 It is along Figure 1 A view in direction A; Figure 6 It is along Figure 1 The view from direction B; Figure 7 It is based on the corresponding variant of the coil assembly. Figure 3 Cross-sectional view; Figure 8 It is based on another variant of the coil assembly corresponding to Figure 5 The view; and Figure 9 It is based on another variant of the coil assembly corresponding to Figure 5 The view. Detailed Implementation

[0010] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular form as used herein is also intended to include the plural form. As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more. It will be further understood that the terms "comprising" and / or "including" specify the presence of the stated features, quantities, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or combinations thereof. Additionally, the terms "set on," "located on," etc., may mean that an element is located above or below the target portion, and do not necessarily mean that the element is located on the upper side of the target portion relative to a direction opposite to the direction of gravity.

[0011] The terms “integrated into” and “connected to” can refer not only to elements that are in direct and physical contact with each other, but also to a structure in which another element is located between the elements such that the elements are also in contact with the other element.

[0012] For ease of description, the dimensions and thicknesses of each element shown in the accompanying drawings are arbitrarily represented, but this disclosure is not limited to the dimensions and thicknesses shown herein.

[0013] In the accompanying drawings, the Z direction can be defined as a third direction or a length direction, the Y direction can be defined as a second direction or a width direction, and the X direction can be defined as a first direction or a thickness direction.

[0014] 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 or corresponding elements are indicated by the same reference numerals, and repeated descriptions thereof will be omitted.

[0015] Various types of electronic components can be used in electronic devices, and various types of coil components can be appropriately used among such electronic components to remove noise.

[0016] In other words, in electronic devices, coil assemblies can be used as power inductors, high-frequency inductors, ordinary ferrite beads, high-frequency ferrite beads (such as ferrite beads suitable for the GHz band), common-mode filters, etc.

[0017] Figure 1 This is a schematic diagram of a coil assembly according to an exemplary embodiment of the present disclosure. Figure 2 yes Figure 1 Top view. Figure 3 It is along Figure 1 A cross-sectional view taken from the I-I' line. Figure 4 It is along Figure 1A cross-sectional view taken from line II-II'. Figure 5 It is along Figure 1 The view from direction A. Figure 6 It is along Figure 1 The view from direction B. In Figure 5 In order to facilitate understanding and description of this example embodiment, the second insulating layer 620 is omitted.

[0018] Reference Figures 1 to 6 According to an exemplary embodiment of this disclosure, a coil assembly 1000 may include a body 100, a coil 300, external electrodes 400 and 500, and a first insulating layer 610, and may also include a support member 200, an insulating film IF, and a second insulating layer 620. Figure 1 In the text, the boundary between the main body 100 and the first insulating layer 610 is omitted.

[0019] The body 100 may form the overall appearance of the coil assembly 1000 according to this example embodiment, and may include a coil 300 embedded in the body 100.

[0020] The main body 100 may have an overall hexahedral shape.

[0021] In the following description, exemplary embodiments of the present disclosure will be described assuming that the body 100 has a hexahedral shape. However, this description does not exclude coil assemblies that include bodies having shapes other than hexahedral shapes from the scope of these exemplary embodiments.

[0022] The body 100 may have a first surface 101 and a second surface 102 opposite to each other in the X direction (first direction), a first side surface 105 and a second side surface 106 opposite to each other in the Y direction (second direction), and a third side surface 103 and a fourth side surface 104 opposite to each other in the Z direction (third direction). The first side surface 105, the second side surface 106, the third side surface 103, and the fourth side surface 104 of the body 100 may respectively correspond to a plurality of side surfaces of the body 100 that connect the first surface 101 and the second surface 102 of the body 100 to each other. When the coil assembly 1000 according to this example embodiment is mounted on a mounting substrate such as a printed circuit board, the first surface 101 of the body 100 may be configured as a mounting surface facing the mounting substrate, thereby allowing the coil assembly 1000 to be mounted on the mounting substrate.

[0023] The body 100 may be configured such that the coil assembly 1000, including external electrodes 400 and 500 and insulating layers 610 and 620 (described below) according to this example embodiment, 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 ​​for the length, width, and thickness of the coil assembly 1000 are theoretical values ​​excluding tolerances; therefore, the actual length, actual width, and actual thickness of the coil assembly 1000 may have different values ​​than those described above due to tolerances.

[0024] The body 100 may include a magnetic material and a resin. Specifically, the body 100 may be formed by laminating one or more magnetic composite sheets in which a magnetic material is dispersed in a resin. However, the body 100 may have a structure other than that in which a magnetic material is dispersed in a resin. For example, the body 100 may be formed using a magnetic material such as ferrite, or it may be formed using a non-magnetic material.

[0025] Magnetic materials can be ferrites or magnetic metal particles.

[0026] Ferrites may include, for example, at least one selected from the group consisting 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.

[0027] Magnetic metal 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 particles may include at least one selected from the group consisting of 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] The magnetic metal particles can be amorphous or crystalline. For example, the magnetic metal particles can be Fe-Si-B-Cr based amorphous alloy particles, but this disclosure is not limited to this.

[0029] In the main body 100, ferrite particles and magnetic metal particles may exist in the form of magnetic particles, and the ferrite particles and magnetic metal particles may each have an average diameter of about 0.1 μm to 30 μm, but the embodiments are not limited thereto.

[0030] The body 100 may include two or more types of magnetic materials dispersed in the resin. Here, different types of magnetic materials mean that the magnetic materials dispersed in the resin are distinguishable from each other in at least one aspect of average diameter, composition, crystallinity, and shape.

[0031] The resin may include, alone or in combination, epoxy resin, polyimide, liquid crystal polymer, etc., but this disclosure is not limited thereto.

[0032] The body 100 may include a core 110 passing through the coil 300, which will be described below. The core 110 may be formed by filling the through-hole of the coil 300 with a magnetic composite sheet, but this disclosure is not limited thereto.

[0033] The support member 200 can be embedded in the main body 100. The support member 200 can support the coil 300, which will be described below.

[0034] The support member 200 can be formed using insulating materials including thermosetting insulating resins such as epoxy resins, thermoplastic insulating resins such as polyimide, or photosensitive insulating resins, or it can be formed using insulating materials formed by impregnating reinforcing materials such as glass fibers or inorganic fillers into the aforementioned thermosetting insulating resins, thermoplastic insulating resins, or photosensitive insulating resins. For example, the support member 200 can be formed using insulating materials such as copper-clad laminates (CCL), prepregs, ABF (Ajinomoto build-up film), FR-4, bismaleimide triazine (BT) resin, photosensitive dielectric (PID), etc., but this disclosure is not limited thereto.

[0035] Inorganic fillers may include 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).

[0036] 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 fiber, the support member 200 can help reduce the overall thickness of the coil 300. When the support member 200 is formed using an insulating material including a photosensitive insulating resin, the number of processes can be reduced. Therefore, this can be advantageous in terms of reducing production costs and allows for the processing of fine holes.

[0037] The coil 300 may be disposed in the body 100 to exhibit the characteristics of the coil assembly 1000. 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 an electronic device by storing an electric field as a magnetic field and maintaining the output voltage.

[0038] A coil 300 may be disposed on at least one surface of the support member 200 to form at least one turn. In this exemplary embodiment, the coil 300 may include: a first coil pattern 311 and a first lead-out 331 disposed on one surface of the second surface 102 of the support member 200 facing the body 100; a second coil pattern 312 and a second lead-out 332 disposed on another surface of the support member 200 opposite to the first surface; and a through-hole 320 passing through the support member 200, the through-hole 320 connecting the first coil pattern 311 and the second coil pattern 312 to each other. As a result, the coil 300 according to this exemplary embodiment may be formed as a single coil that generates a magnetic field around the core 110 in a first direction (X direction) of the body 100.

[0039] Each of the first coil pattern 311 and the second coil pattern 312 may be in the form of a planar spiral shape having at least one turn around the core 110 of the body 100. For example, relative to Figure 1 , Figure 3 and Figure 4 In the direction of the first coil pattern 311, at least one turn may be formed around the core 110 on the upper surface (one surface) of the support member 200. The second coil pattern 312 may be formed around the core 110 on the lower surface (another surface) of the support member 200.

[0040] Leads 331 and 332 can be connected to coil patterns 311 and 312 respectively, and can extend to the third side surface 103 and the fourth side surface 104 of the main body 100 respectively. Specifically, the first lead 331 can be disposed on one surface (upper surface) of the support member 200, can be connected to the first coil pattern 311, and can extend to the third side surface 103 of the main body 100. The second lead 332 can be disposed on the other surface (lower surface) of the support member 200, can be connected to the second coil pattern 312, and can extend to the fourth side surface 104 of the main body 100. Leads 331 and 332 can extend to the third side surface 103 and the fourth side surface 104 of the main body 100 respectively, and can contact and connect to the external electrodes 400 and 500 respectively, which will be described below.

[0041] The distance between the leads 331 and 332 and the first side surface 105 may be different from the distance between the leads 331 and 332 and the second side surface 106. (Refer to...) Figure 2 The leads 331 and 332 may be configured to be closer to the second side surface 106 than the first side surface 105. However, this disclosure is not limited thereto; the leads 331 and 332 may also be configured to be closer to the first side surface 105 than the second side surface 106. As described above, the leads 331 and 332 may be configured to be closer to either the first side surface 105 or the second side surface 106, thereby ensuring the hollow dimension.

[0042] At least one of the coil patterns 311 and 312, the via 320, and the leads 331 and 332 may include at least one conductive layer.

[0043] For example, when the first coil pattern 311, via 320, and first lead-out 331 are formed by plating, each of the first coil pattern 311, via 320, and first lead-out 331 may include a seed layer formed by chemical plating or vapor deposition such as sputtering, as well as an electroplated layer. Here, the electroplated layer may have a single-layer structure or a multi-layer structure. An electroplated layer with a multi-layer structure may be formed as a conformal film structure in which one electroplated layer covers another electroplated layer, or it may be formed as a shape in which one electroplated layer is laminated only on one surface of another electroplated layer. The seed layer of the first coil pattern 311, the seed layer of the via 320, and the seed layer of the first lead-out 331 may be formed integrally, such that no boundary is formed between the seed layer of the first coil pattern 311, the seed layer of the via 320, and the seed layer of the first lead-out 331, but this disclosure is not limited thereto. The electroplating layer of the first coil pattern 311, the electroplating layer of the via 320, and the electroplating layer of the first lead 331 can also be integrally formed, so that no boundary is formed between the electroplating layer of the first coil pattern 311, the electroplating layer of the via 320, and the electroplating layer of the first lead 331, but this disclosure is not limited thereto.

[0044] As another example, when the first coil pattern 311 and the second coil pattern 312 are formed separately and then co-laminated onto the support member 200 to form the coil 300, the via 320 may include a high-melting-point metal layer and a low-melting-point metal layer with a melting point lower than that of the high-melting-point metal layer. Here, the low-melting-point metal layer may be formed using solder comprising lead (Pb) and / or tin (Sn). At least a portion of the low-melting-point metal layer may melt due to the pressure and temperature during co-lamination, and an intermetallic compound (IMC) layer may be formed at the boundary between the low-melting-point metal layer and the first coil pattern 311.

[0045] For example, the first coil pattern 311 and the second coil pattern 312 may be formed protrudingly on the upper and lower surfaces of the support member 200, respectively. As another example, the first coil pattern 311 may be embedded in the upper surface of the support member 200, such that the upper surface of the first coil pattern 311 is exposed from the upper surface of the support member 200, and the second coil pattern 312 may be formed protrudingly on the lower surface of the support member 200. In this case, a recess may be formed on the upper surface of the first coil pattern 311, and the upper surface of the support member 200 and the upper surface of the first coil pattern 311 may not be coplanar. As another example, the first coil pattern 311 may be embedded in the upper surface of the support member 200, such that the upper surface of the first coil pattern 311 is exposed from the upper surface of the support member 200, and the second coil pattern 312 may be embedded in the lower surface of the support member 200, such that the lower surface of the second coil pattern 312 is exposed from the lower surface of the support member 200.

[0046] Each of the coil patterns 311 and 312, the via 320, and the leads 331 and 332 may include a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), molybdenum (Mo), or alloys thereof, but this disclosure is not limited thereto.

[0047] External electrodes 400 and 500 may be disposed on the third side surface 103 and the fourth side surface 104 of the main body 100, respectively, and may extend to the first surface 101 of the main body 100. External electrodes 400 and 500 may be connected to leads 331 and 332, respectively, so that when the coil assembly 1000 is mounted on an electronic device, external electrodes 400 and 500 may be used to electrically connect the coil 300 in the coil assembly 1000 to the electronic device.

[0048] External electrodes 400 and 500 may include: a first external electrode 400 disposed on a third side surface 103 of the body 100, the first external electrode 400 being connected to a first lead-out portion 331; and a second external electrode 500 disposed on a fourth side surface 104 of the body 100, the second external electrode 500 being connected to a second lead-out portion 332. The first external electrode 400 and the second external electrode 500 may be spaced apart from each other in a third direction (Z direction) such that the first external electrode 400 and the second external electrode 500 may not contact each other on a first surface 101 of the body 100. In the following description, the first external electrode 400 will be described as a representative example, and some descriptions of the first external electrode 400 may also be applied to the second external electrode 500; therefore, repeated descriptions of the second external electrode 500 will be omitted.

[0049] The first external electrode 400 may include: a first connecting portion 411 disposed on the third side surface 103 of the main body 100; and a first extension portion 412 extending from the first connecting portion 411 to the first surface 101 of the main body 100. The second external electrode 500 may include: a second connecting portion 511 disposed on the fourth side surface 104 of the main body 100; and a second extension portion 512 extending from the second connecting portion 511 to the first surface 101 of the main body 100.

[0050] The first connecting portion 411 may be disposed on the third side surface 103 of the main body 100, and may contact and connect to the first lead-out portion 331. For example... Figure 5 As shown, at least a portion of the first connecting portion 411 may be disposed in the opening O of the first insulating layer 610, which will be described later, and the side surface of the first connecting portion 411 may contact the first insulating layer 610.

[0051] like Figure 5 As shown, the distance d1 between the side of the first connecting portion 411 closest to the first side surface 105 and the first side surface 105 may be different from the distance d2 between the other side of the first connecting portion 411 closest to the second side surface 106 and the second side surface 106. (Refer to...) Figure 5 The distance d1 can be greater than the distance d2. The difference between the values ​​of d1 and d2 can mean, for example, that d1 and d2 have a length difference of 100 μm or more. However, this disclosure is not limited thereto, and the difference between the values ​​of d1 and d2 can include cases where there is a meaningful length difference based on the dimensions of the coil assembly 1000.

[0052] In addition, such as Figure 5As shown, connecting portions 411 and 511 may be provided only on one side of the intermediate surface M located between the first side surface 105 and the second side surface 106 of the main body 100. The distance d1 between the first connecting portion 411 and the first side surface 105 can be measured by the following method: The first insulating layer 610 can be removed from the coil assembly 1000 to obtain the length of the line segment connecting the first side surface 105 and the first connecting portion 411 to each other and parallel to the second direction (Y direction). In this case, five arbitrary points spaced apart from each other in the first direction (X direction) can be selected, and the lengths of multiple line segments at the five points can be obtained. The distance between the first connecting portion 411 and the first side surface 105 may refer to the arithmetic mean of the lengths of the multiple line segments. Similarly, the distance d2 between the first connecting portion 411 and the second side surface 106 can be measured in a manner similar to the description above.

[0053] As described above, the first connecting portion 411 may be configured to be closer to the second side surface 106 than the first side surface 105 of the body 100. However, this disclosure is not limited to this, and the first connecting portion 411 may be configured to be closer to the first side surface 105 than the second side surface 106 of the body 100. Additionally, as... Figure 8 As shown, the connecting parts 411 and 511 can be configured to span across the intermediate surface M.

[0054] To reduce the parasitic capacitance between coil 300 and external electrodes 400 and 500, the distance between coil 300 and external electrodes 400 and 500 can be adjusted. In the coil assembly according to the prior art, the outermost point of the outermost turn of coil 300 in the third direction (Z direction) may be located on the same line as external electrodes 400 and 500 in the third direction (Z direction). Therefore, in order to adjust the distance between coil 300 and external electrodes 400 and 500, it may be necessary to adjust the edge distance of coil 300 in the third direction (Z direction) (e.g., the distance between the outermost turn of coil 300 and the side surface of body 100 in the third direction (Z direction)). In this case, although the SRF characteristics can be improved, the size of the hollow core will be reduced, resulting in a decrease in saturation current (Isat) and an increase in DC resistance (Rdc).

[0055] Conversely, in the coil assembly 1000 according to this example embodiment, the first connection portion 411 may be configured to be offset from the center of the third side surface 103 of the body 100 in the second direction, which increases the distance in the third direction between the first connection portion 411 and the coil 300 (e.g., the outermost turns of the coil patterns 311 and 312 of the coil 300). Therefore, the distance between the coil 300 and the outer electrodes 400 and 500 can be adjusted without changing the edge spacing of the coil 300. (Refer to...) Figure 2The outermost point of the outermost turn of coil 300 in the third direction (Z direction) may not be on the same line as the first connecting portion 411 in the third direction (Z direction). That is, the outermost point of the outermost turns of coil patterns 311 and 312 of coil 300 in the third direction (Z direction) may not be on the same line as the connecting portions 411 and 511 in the third direction (Z direction), and may be offset in the second direction (Y direction). Therefore, the hollow size of coil 300 can be ensured while sufficiently guaranteeing the distance between coil 300 and the first connecting portion 411, thereby improving the self-resonant frequency (SRF) characteristics.

[0056] Reference Figure 2 The second connecting portion 511 may be positioned on the fourth side surface 104 of the main body 100, closer to the second side surface 106 than the first side surface 105. That is, the second connecting portion 511 may also be misaligned in the same direction as the misalignment direction of the first connecting portion 411 (i.e., connecting portions 411 and 511 may be offset relative to the intermediate surface M between the first side surface 105 and the second side surface 106 in the same direction in the second direction (Y direction)). Therefore, when viewed from a third-party upward perspective, the first connecting portion 411 and the second connecting portion 511 may at least partially overlap each other.

[0057] The first extension 412 can be connected to the first connecting portion 411 and is disposed on the first surface 101 of the body 100. The first extension 412 and the second extension 512 can be disposed on the first surface 101 of the body 100 and spaced apart from each other in the third direction (Z direction). At least a portion of the first extension 412 can be disposed in the opening O of the first insulating layer 610, which will be described below, and the side surface of the first extension 412 can contact the first insulating layer 610.

[0058] External electrodes 400 and 500 can be formed on the surface of the body 100 by electroplating using a first insulating layer 610 formed on the surface of the body 100 as a plating resist. When the body 100 includes magnetic particles, the magnetic particles can be exposed on the surface of the body 100. Due to the magnetic particles exposed on the surface of the body 100, the surface of the body 100 can be conductive during electroplating, and external electrodes 400 and 500 can be formed on the surface of the body 100 by electroplating.

[0059] The connecting portions 411 and 511 of the external electrodes 400 and 500, along with the extension portions 412 and 512, can be formed using the same plating process, so that no boundary is formed between them. That is, the first connecting portion 411 and the first extension portion 412 can be integrally formed, and the second connecting portion 511 and the second extension portion 512 can be integrally formed. Furthermore, the connecting portions 411 and 511, along with the extension portions 412 and 512, can be formed from the same metal. However, this description does not exclude the possibility that the connecting portions 411 and 511 and the extension portions 412 and 512 are formed using different plating processes, thus creating a boundary between them, from the scope of this disclosure.

[0060] The external electrodes 400 and 500 may include conductive materials, such as at least one selected from the group consisting of copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), and alloys thereof, but this disclosure is not limited thereto.

[0061] The outer electrodes 400 and 500 can be formed to have a thickness in the range of 0.5 μm to 100 μm. When the thickness of the outer electrodes 400 and 500 is less than 0.5 μm, detachment or delamination may occur when they are mounted on the substrate. When the thickness of the outer electrodes 400 and 500 is greater than 100 μm, it may be detrimental to reducing the thickness of the coil assembly 1000.

[0062] The first insulating layer 610 may be disposed on the third side surface 103 and the fourth side surface 104 of the body 100 to expose the connecting portions 411 and 511. Alternatively, the first insulating layer 610 may be disposed on the first surface 101, the second surface 102, the first side surface 105, and the second side surface 106 of the body 100. The first insulating layer 610 may be formed to surround the entire surface of the body 100 together with the external electrodes 400 and 500. The first insulating layer 610 may be used as a plating resist during the formation of the external electrodes 400 and 500 by electroplating, but this disclosure is not limited thereto.

[0063] The opening O, where the external electrodes 400 and 500 are disposed, can be formed in the first insulating layer 610. The opening O in the first insulating layer 610 can be formed on the third side surface 103, the fourth side surface 104, and the first surface 101 of the body 100. The opening O can extend from the third side surface 103 to the first surface 101, and from the fourth side surface 104 to the first surface 101. (Refer to...) Figure 5 and Figure 6 At least a portion of the connecting portions 411 and 511 and the extension portions 412 and 512 may be provided in the opening O.

[0064] Therefore, the first insulating layer 610 exposes the connecting portions 411 and 511 as well as the extension portions 412 and 512.

[0065] The first insulating layer 610 may include thermoplastic resins (such as polystyrene resins, vinyl acetate resins, polyester resins, polyethylene resins, polypropylene resins, polyamide resins, rubber resins, acrylic resins, etc.), thermosetting resins (such as phenolic resins, epoxy resins, polyurethane resins, melamine resins, alkyd resins, etc.), photosensitive resins, parylene, SiO x (0 < x < 1) or SiN x (0 < x < 1).

[0066] The first insulating layer 610 may have an adhesive function. For example, when the first insulating layer 610 is formed by laminating an insulating film on the main body 100, the insulating film may include an adhesive component, so that the insulating film can be attached to the surface of the main body 100. In this case, an adhesive layer may be formed on one surface of the first insulating layer 610. However, in some cases, such as when using a semi-cured (B-stage) insulating film to form the first insulating layer 610, the adhesive layer may not be formed on this one surface of the first insulating layer 610.

[0067] The first insulating layer 610 can be formed by coating a liquid insulating resin on the surface of the main body 100, laminating an insulating film on the surface of the main body 100, or forming an insulating resin on the surface of the main body 100 by vapor deposition. Examples of the insulating film may include a dry film (DF) containing a photosensitive insulating resin, an Ajinomoto build-up film (ABF) that does not contain a photosensitive insulating resin, or a polyimide film.

[0068] The first insulating layer 610 can be formed to have a thickness in the range of 10 nm to 100 μm. When the thickness of the first insulating layer 610 is less than 10 nm, the characteristics of the coil assembly 1000 may deteriorate, such as a decrease in Q factor, breakdown voltage, and self-resonant frequency (SRF). When the thickness of the first insulating layer 610 is greater than 100 μm, the total length, total width, and total thickness of the coil assembly 1000 may increase, which may not be conducive to reducing the thickness.

[0069] Hereinafter, the arrangement relationship between the first insulating layer 610 and the first external electrode 400 will be described based on the third side surface 103 of the main body 100. However, this description can equally apply to the first insulating layer 610 and the second external electrode 500 provided on the fourth side surface 104 of the main body 100.

[0070] Refer to Figure 5A first insulating layer 610 may be disposed on the third side surface 103 of the body 100, and may have a region 610R1 and another region 610R2 spaced apart from each other in a second direction (Y direction). For example, after the first insulating layer 610 is formed on the entire third side surface 103 of the body 100, an opening O in the form of a slit extending in a first direction (X direction) may be formed in the first insulating layer 610 to expose a portion of the third side surface 103 of the body 100, thereby separating the region 610R1 and the other region 610R2 of the first insulating layer 610 from each other. The opening O may be formed in the first insulating layer 610 by physical and / or chemical processing methods, and may expose the third side surface 103 of the body 100. A first connection portion 411 of the first external electrode 400 may be formed on the third side surface 103 of the body 100 exposed through the opening O. The first connecting part 411 may be disposed between one region 610R1 and another region 610R2 of the first insulating layer 610, and may contact and connect to the first lead-out part 331.

[0071] The length of one region 610R1 in the second direction (Y direction) may differ from the length of another region 610R2 in the second direction (Y direction). As described above, the first connecting portion 411 may be positioned closer to the second side surface 106 than the first side surface 105 of the body 100, thus the length of one region 610R1 in the second direction (Y direction) may be greater than the length of another region 610R2 in the second direction. However, this disclosure is not limited to this, and the length of another region 610R2 in the second direction may also be greater than the length of one region 610R1 in the second direction (Y direction).

[0072] The length of a region 610R1 in the second direction (Y direction) can be measured by the following method: The length of a line segment parallel to the second direction (Y direction) can be obtained, connecting the two outermost boundary lines of a region 610R1 that are opposite each other in the second direction (Y direction). In this case, five arbitrary points spaced apart from each other in the first direction (X direction) can be selected, and the lengths of multiple line segments at these five points can be obtained. The length of a region 610R1 in the second direction (Y direction) can be the arithmetic mean of the lengths of these multiple line segments. Similarly, the length of another region 610R2 in the second direction (Y direction) can be measured in a manner similar to the description above.

[0073] The second insulating layer 620 may be disposed on each of the third side surface 103 and the fourth side surface 104 of the main body 100, and may cover the first insulating layer 610 disposed on the third side surface 103 and the fourth side surface 104 of the main body 100, as well as the connection portions 411 and 511. The second insulating layer 620 may cover the first connection portion 411 of the first external electrode 400 and the second connection portion 511 of the second external electrode 500, thereby preventing the coil assembly 1000 according to the present exemplary embodiment from being short-circuited with other electronic components installed adjacent thereto when installed on a mounting substrate such as a printed circuit board.

[0074] The second insulating layer 620 may include thermoplastic resins (such as polystyrene resins, vinyl acetate resins, polyester resins, polyethylene resins, polypropylene resins, polyamide resins, rubber resins, acrylic resins, etc.), thermosetting resins (such as phenolic resins, epoxy resins, polyurethane resins, melamine resins, alkyd resins, etc.), photosensitive resins, parylene, SiO x (0 < x < 1) or SiN x (0 < x < 1).

[0075] The second insulating layer 620 may have an adhesive function. For example, when the second insulating layer 620 is formed by laminating an insulating film on the first insulating layer 610 and the connection portions 411 and 511, the insulating film may include an adhesive component. In this case, an adhesive layer may be formed on one surface of the second insulating layer 620. However, in some cases, such as when using a semi-cured (B-stage) insulating film to form the second insulating layer 620, the adhesive layer may not be formed on this one surface of the second insulating layer 620.

[0076] The second insulating layer 620 may be formed by coating a liquid insulating resin on the surfaces of the first insulating layer 610 and the connection portions 411 and 511, laminating an insulating film on the surfaces of the first insulating layer 610 and the connection portions 411 and 511, or forming an insulating resin on the surfaces of the first insulating layer 610 and the connection portions 411 and 511 by vapor deposition. Examples of the insulating film may include DF containing a photosensitive insulating resin, ABF not containing a photosensitive insulating resin, or a polyimide film.

[0077] The second insulating layer 620 may be formed to have a thickness in the range of 10 nm to 100 μm. When the thickness of the second insulating layer 620 is less than 10 nm, the characteristics of the coil assembly 1000 may be degraded, such as a decrease in Q factor, breakdown voltage, and SRF. When the thickness of the second insulating layer 620 is greater than 100 μm, the total length, total width, and total thickness of the coil assembly 1000 may increase, which may be disadvantageous for reducing the thickness.

[0078] [[ID=十九]]The insulating film IF may be disposed along the surface of the coil 300.

[0079] The insulating film IF insulates the coil 300 from the body 100. The insulating film IF can cover the outer surface of the coil 300, thereby insulating the coil 300 from the body 100. The insulating film IF can be disposed between adjacent turns of the coil, and can also be disposed on the support member 200.

[0080] The insulating film IF may include known insulating materials such as parylene, but this disclosure is not limited thereto. As another example, the insulating film IF may include insulating materials such as epoxy resin instead of parylene. The insulating film IF may be formed by vapor deposition, but this disclosure is not limited thereto. As another example, the insulating film IF may be formed by laminating and curing an insulating film for forming the insulating film IF on the two surfaces of the support member 200 on which the coil 300 is formed. Alternatively, the insulating film IF may be formed by coating an insulating paste for forming the insulating film IF on the two surfaces of the support member 200 on which the coil 300 is formed and curing it.

[0081] In this disclosure, the insulating film IF may be an optional element. The insulating film IF may be omitted when the body 100 can ensure sufficient resistance under the operating conditions of the coil assembly 1000 according to this example embodiment.

[0082] Figure 7 It is based on the corresponding variant of the coil assembly. Figure 3 Cross-sectional view.

[0083] Reference Figure 7 The coil assembly 1000' according to this example embodiment may differ from the coil assembly 1000 according to the example embodiment of this disclosure in terms of the external electrodes 400 and 500.

[0084] External electrodes 400 and 500 may further include metal layers 420 and 520 respectively disposed on extensions 412 and 512. Specifically, the first external electrode 400 may include: a first electrode layer 410, including a first connecting portion 411 and a first extension 412; and a first metal layer 420 disposed on the first extension 412. The second external electrode 500 may include: a second electrode layer 510, including a second connecting portion 511 and a second extension 512; and a second metal layer 520 disposed on the second extension 512. Metal layers 420 and 520 may include nickel (Ni) and / or tin (Sn). Figure 7 As shown, each of the metal layers 420 and 520 may be formed as multiple layers. In this case, each of the metal layers 420 and 520 may have a double-layer structure, which includes a nickel (Ni) plating disposed on each of the extensions 412 and 512 and a tin (Sn) plating disposed on the nickel (Ni) plating, but this disclosure is not limited thereto.

[0085] Figure 8 It is based on another variant of the coil assembly corresponding to Figure 5 The view.

[0086] Reference Figure 8 The coil assembly 1000'' according to this example embodiment may differ from the coil assembly 1000 according to the example embodiment of this disclosure in terms of the arrangement of the connecting portions 411 and 511.

[0087] The connecting portions 411 and 511 can be configured to span the intermediate surface M located between the first side surface 105 and the second side surface 106 of the main body 100. (See reference...) Figure 8 At least a portion of the connecting portions 411 and 511 may be disposed on both sides of the intermediate surface M. For example, the shorter portion of the connecting portions 411 and 511 in the second direction is disposed on one side of the intermediate surface M, and the longer portion of the connecting portions 411 and 511 in the second direction is disposed on the other side of the intermediate surface M.

[0088] Figure 9 It is based on another variant of the coil assembly corresponding to Figure 5 The view.

[0089] Reference Figure 9 The coil assembly 1000 according to this example embodiment may differ from the coil assembly 1000 according to the example embodiment of this disclosure in terms of the shape of the first insulating layer 610 and the height of the connecting portions 411 and 511.

[0090] The opening O of the first insulating layer 610 may not extend to the second surface 102 of the body 100. Therefore, the first insulating layer 610 may not have one region and another region spaced apart from each other in the second direction (Y direction).

[0091] The height H of the first connecting part 411 411 It can be less than the distance H between the first surface 101 and the second surface 102 of the main body 100. 100 That is to say, the height H of the first connecting part 411 411 The height can be less than that of the main body 100. By reducing the height of the first connecting portion 411, the area of ​​the external electrode forming the parasitic capacitance can be reduced, and the SRF characteristics can be improved.

[0092] 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 has a first surface and a second surface that are opposite to each other in a first direction, a first side surface and a second side surface that are opposite to each other in a second direction, and a third side surface that connects the first side surface and the second side surface to each other. A coil is disposed in the body, the coil including a lead extending to the third side surface of the body; An external electrode is disposed on the third side surface of the main body, the external electrode including a connecting portion connected to the lead-out portion; and A first insulating layer is disposed on the third side surface of the main body on the portion where the connecting portion is not located, such that the first insulating layer exposes the connecting portion. The distance between the connecting portion of the external electrode and the first side surface of the main body is different from the distance between the connecting portion of the external electrode and the second side surface of the main body.

2. The coil assembly as claimed in claim 1, wherein, The first insulating layer has an opening, and at least a portion of the connecting portion is disposed in the opening. The side surface of the connector is in contact with the first insulating layer.

3. The coil assembly as claimed in claim 1, wherein, The external electrode also includes an extension connected to the connection portion, the extension portion being disposed on the first surface of the body.

4. The coil assembly as claimed in claim 1, wherein, The length of the connecting portion in the first direction is less than the distance between the first surface and the second surface of the main body.

5. The coil assembly as claimed in claim 1, wherein, The connecting part is only provided on one side of the intermediate surface located between the first side surface and the second side surface.

6. The coil assembly as claimed in claim 1, wherein, The body also has a fourth side surface that is opposite the third side surface of the body in a third direction.

7. The coil assembly of claim 6, wherein, The external electrode is also disposed on the fourth side surface of the main body, and includes a first external electrode disposed on the third side surface of the main body and a second external electrode disposed on the fourth side surface of the main body. When viewed from above by the third party, the connection portion of the first external electrode and the connection portion of the second external electrode are at least partially overlapped with each other.

8. The coil assembly of claim 6, wherein, The lead-out portion also extends to the fourth side surface of the body, and includes a first lead-out portion extending to the third side surface of the body and a second lead-out portion extending to the fourth side surface of the body.

9. The coil assembly of claim 1, further comprising: A second insulating layer covers the first insulating layer and the connection portion.

10. The coil assembly of claim 3, wherein, The external electrode also includes a metal layer disposed on the extension, and The metal layer comprises nickel and / or tin.

11. A coil assembly, comprising: The main body has a first surface and a second surface that are opposite to each other in a first direction, a first side surface and a second side surface that connect the first surface and the second surface to each other, and a third side surface that connects the first side surface and the second side surface to each other, wherein the first side surface and the second side surface are opposite to each other in a second direction; A coil is disposed in the body, the coil including a lead extending to the third side surface of the body; A first insulating layer is disposed on the third side surface of the body, the first insulating layer having a region and another region spaced apart from each other in the second direction; as well as The external electrode includes a connecting portion connected to the lead-out portion, the connecting portion being disposed on the third side surface of the body and between the one region and the other region of the first insulating layer. The length of one region in the second direction is different from the length of the other region in the second direction.

12. The coil assembly of claim 11, wherein, The first insulating layer exposes the connection portion.

13. The coil assembly of claim 11, further comprising: A second insulating layer covers the connection portion, one region of the first insulating layer, and the other region.

14. The coil assembly of claim 11, wherein, The external electrode also includes an extension connected to the connection portion, the extension portion being disposed on the first surface of the body.

15. The coil assembly of claim 11, wherein, The connecting portion is disposed on both sides of an intermediate surface located between the first side surface and the second side surface, and the length of a portion of the connecting portion disposed on one side of the intermediate surface is shorter than the length of another portion of the connecting portion disposed on the other side of the intermediate surface.

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