Coil assembly

Abstract

A coil assembly is provided. The coil assembly includes a main body having an upper surface and a lower surface opposite to each other in a thickness direction, a support substrate disposed in the main body and having a surface perpendicular to the lower surface of the main body, a coil portion disposed on the support substrate, and first and second outer electrodes disposed on the lower surface of the main body. The main body includes an effective portion covering the coil portion, and first and second cover portions disposed on opposite surfaces of the effective portion, respectively. The effective portion includes first magnetic metal particles, second magnetic metal particles, and a first insulating resin, the second magnetic metal particles having a smaller diameter than the first magnetic metal particles. Each of the first and second cover portions includes third magnetic metal particles and a second insulating resin, the third magnetic metal particles having a smaller diameter than the first magnetic metal particles.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0125602, filed on September 28, 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 number of electronic components used in them increases, and electronic devices are miniaturized.

[0005] In the case of a thin-film coil assembly, the main body is formed by stacking a magnetic composite sheet in which magnetic metal particles are dispersed in an insulating resin onto a substrate (on which a coil portion is formed by a plating process) and curing the stacked magnetic composite sheet, and forming an external electrode on the surface of the main body. Summary of the Invention

[0006] One aspect of this disclosure is to provide a coil assembly that can easily prevent short circuits between external electrodes, wherein the coil portion is configured to be perpendicular to the lower surface of the body.

[0007] Another aspect of this disclosure is to provide a coil assembly capable of increasing the effective volume of a magnetic material, wherein the coil portion is configured to be perpendicular to the lower surface of the body.

[0008] According to one aspect of this disclosure, a coil assembly includes: a body having an upper surface and a lower surface opposite to each other in the thickness direction of the body; a support substrate disposed in the body and having a surface perpendicular to the lower surface of the body; a coil portion disposed on at least one surface of the support substrate; and a first external electrode and a second external electrode, spaced apart from each other and disposed on the lower surface of the body and respectively connected to the coil portion. The body includes an effective portion and a first covering portion and a second covering portion, the effective portion covering the coil portion, the first covering portion and the second covering portion being respectively disposed on the upper and lower surfaces of the effective portion opposite to each other in the thickness direction. The effective portion includes a first magnetic metal particle, a second magnetic metal particle, and a first insulating resin, the diameter of the second magnetic metal particle being smaller than the diameter of the first magnetic metal particle. Each of the first and second covering portions includes a third magnetic metal particle and a second insulating resin, the diameter of the third magnetic metal particle being smaller than the diameter of the first magnetic metal particle.

[0009] According to one aspect of this disclosure, a coil assembly includes: a body having a lower surface; a support substrate disposed in the body and having a surface perpendicular to the lower surface of the body; and a coil portion disposed on at least one surface of the support substrate. The body includes an effective portion and a first cover portion, a second cover portion, a third cover portion, and a fourth cover portion, the effective portion covering the coil portion. The first cover portion, the second cover portion, the third cover portion, and the fourth cover portion are respectively disposed on an upper surface of the effective portion, a lower surface of the effective portion, a side surface of the effective portion, and a other side surface of the effective portion. Each of the effective portion, the first cover portion, the second cover portion, the third cover portion, and the fourth cover portion includes magnetic metal particles and insulating resin. The filling rate of the magnetic metal particles in the effective portion is greater than the filling rate of the magnetic metal particles in each of the first cover portion, the second cover portion, the third cover portion, and the fourth cover portion.

[0010] According to one aspect of this disclosure, a coil assembly includes: a body having an upper surface and a lower surface opposite to each other; a coil portion disposed perpendicularly in the body relative to the lower surface of the body; and a first external electrode and a second external electrode, each including a pad portion, the pad portions being disposed spaced apart from each other on the lower surface of the body and connected to the coil portion. The average size of metal particles dispersed in a portion of the body that contacts one of the pad portions is smaller than the average size of metal particles dispersed in another portion of the body that is spaced apart from the outer surface of the body. Attached Figure Description

[0011] The above and other aspects, features and advantages of this disclosure will be more clearly understood from the following detailed embodiments in conjunction with the accompanying drawings.

[0012] Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment of the present disclosure.

[0013] Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0014] Figure 3 It is along Figure 1 The cross-sectional view taken from line II-II'.

[0015] Figure 4 This is a schematic perspective view of another coil assembly according to exemplary embodiments of the present disclosure.

[0016] Figure 5 It is along Figure 4 The cross-sectional view taken from line III-III'.

[0017] Figure 6 It is along Figure 4 The cross-sectional view taken from line IV-IV'.

[0018] Figure 7 This is a schematic perspective view of another coil assembly according to exemplary embodiments of the present disclosure.

[0019] Figure 8 It is along Figure 7 A cross-sectional view taken from line V-V'.

[0020] Figure 9 It is along Figure 7 The cross-sectional view taken from line VI-VI'. Detailed Implementation

[0021] 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, and 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.

[0022] 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.

[0023] For ease of description, the dimensions and thicknesses of the elements shown in the accompanying drawings are indicated by way of example, and this disclosure is not limited thereto.

[0024] In the attached figures, the L direction is the first direction or the length (longitudinal) direction, the W direction is the second direction or the width direction, and the T direction is the third direction or the thickness direction.

[0025] 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.

[0026] 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.

[0027] In other words, in electronic devices, coil assemblies can be used as power inductors, high-frequency (HF) inductors, general-purpose ferrite beads, high-frequency (e.g., GHz band) ferrite beads, common-mode filters, etc.

[0028] Figure 1 This is a schematic perspective view of a coil assembly according to an exemplary embodiment. Figure 2 It is along Figure 1 The cross-sectional view taken by line I-I', and Figure 3 It is along Figure 1 The cross-sectional view taken from line II-II'. For ease of description, in Figure 2 In the middle, based on along Figure 1 The cross-section taken by line I-I' shows the internal structure of the coil assembly.

[0029] Reference Figures 1 to 3 According to an exemplary embodiment, the coil assembly 1000 may include a main body 100, a support substrate 200, a coil portion 300, and external electrodes 410 and 420. The main body 100 may include an effective portion 110 and a first cover portion 121, a second cover portion 122, a third cover portion 123, and a fourth cover portion 124.

[0030] The main body 100 can form the appearance of the coil assembly 1000 according to this embodiment, and the support substrate 200 and the coil portion 300 can be embedded in the main body 100.

[0031] The main body 100 can be formed into an overall hexahedral shape.

[0032] based on Figures 1 to 3The 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. In the following, the two end surfaces 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 of the main body 100 may refer to the third surface 103 and the fourth surface 104 of the main body 100, respectively. In addition, the lower surface and the upper surface of the main body 100 may refer to the sixth surface 106 and the fifth surface 105, respectively.

[0033] The main body 100 may be configured such that the coil assembly 1000, including the external electrodes 410 and 420 described later, has a length of 1.0 mm, a width of 0.5 mm, and a thickness of 0.6 mm, or a length of 1.6 mm, a width of 0.8 mm, and a thickness of 1.0 mm, but is not limited thereto. Since the above dimensions of the coil assembly 1000 are merely illustrative, cases where the size of the coil assembly 1000 is smaller or larger than the above dimensions are not excluded from the scope of this disclosure.

[0034] The aforementioned length of the coil assembly 1000 may refer to the maximum length of a plurality of line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image of the coil assembly 1000 at its central portion in the width direction W and are parallel to the length direction L of the coil assembly 1000, as seen in the cross-sectional image of the coil assembly 1000 in the width direction W and in the thickness direction T. Alternatively, the length of the coil assembly 1000 may refer to the arithmetic mean of the lengths of at least three line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image and are parallel to the length direction L of the coil assembly 1000.

[0035] The aforementioned thickness of the coil assembly 1000 may refer to: the maximum value among the lengths of multiple line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image along the length direction L-thickness direction T, based on an optical microscope or scanning electron microscope (SEM) image of the coil assembly 1000 at its central portion in the width direction W, and parallel to the thickness direction T of the coil assembly 1000. Alternatively, the thickness of the coil assembly 1000 may refer to: the arithmetic mean of the lengths of at least three line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image and parallel to the thickness direction T of the coil assembly 1000.

[0036] The aforementioned width of the coil assembly 1000 may refer to: the maximum value among multiple line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image of the coil assembly 1000 at its central portion in the length direction L and are parallel to the width direction W of the coil assembly 1000, based on an optical microscope or scanning electron microscope (SEM) image of the coil assembly 1000 in the cross-sectional image at its central portion in the length direction L. Alternatively, the width of the coil assembly 1000 may refer to: the arithmetic mean of the lengths of at least three line segments that connect the outermost boundary lines of the coil assembly 1000 shown in the cross-sectional image and are parallel to the width direction W of the coil assembly 1000.

[0037] Optionally, the length, width, and thickness of the coil assembly 1000 can 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. 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 two or more measurements. This can be equivalently applied to the width and thickness of the coil assembly 1000.

[0038] The main body 100 may include magnetic metal particles (or metal powder particles) P1, P2, P3, and P4, and insulating resins R1, R2, and R3. The main body 100 is formed by stacking one or more magnetic composite sheets, the magnetic composite sheets including insulating resins R1, R2, or R3 and magnetic metal particles P1, P2, P3, or P4 dispersed in the insulating resins R1, R2, or R3.

[0039] The main body 100 includes an effective part 110 and covering parts 121, 122, 123 and 124.

[0040] Specifically, the effective portion 110 may cover the coil portion 300, which will be described later, and may include a first magnetic metal particle P1, a second magnetic metal particle P2, and a first insulating resin R1, wherein the diameter of the second magnetic metal particle P2 is smaller than the diameter of the first magnetic metal particle P1. A first covering portion 121 may be disposed on the upper surface of the effective portion 110 and may include a third magnetic metal particle P3 and a second insulating resin R2, wherein the diameter of the third magnetic metal particle P3 is smaller than the diameter of the first magnetic metal particle P1. A second covering portion 122 may be disposed on the lower surface of the effective portion 110 and may include a third magnetic metal particle P3 and a second insulating resin R2, wherein the diameter of the third magnetic metal particle P3 is smaller than the diameter of the first magnetic metal particle P1. Third covering portions 123 and fourth covering portions 124 may be respectively disposed on the side surfaces of the effective portion 110 that are opposite each other in the width direction W. Each of the third covering portions 123 and fourth covering portions 124 may include a fourth magnetic metal particle P4 and a third insulating resin R3, wherein the diameter of the fourth magnetic metal particle P4 is smaller than the diameter of the first magnetic metal particle P1. In this specification, the diameter (or size) or average diameter (or average size) of the magnetic metal particles may refer to the particle size distribution represented by D50 or D90, for example, D50 or D90 is measured based on an optical microscope or scanning electron microscope (SEM) image of a cross-section of the body 100. Other methods and / or tools understood by those skilled in the art may be used even if not described in this disclosure.

[0041] The effective portion 110 can be formed by laminating a first magnetic composite sheet onto one surface and another surface of the support substrate 200, which will be described later, that are opposite each other in the width direction W. The first magnetic composite sheet includes a first magnetic metal particle P1 and a second magnetic metal particle P2, as well as a first insulating resin R1. Since the effective portion 110 includes the first magnetic metal particle P1 with a relatively large diameter and the second magnetic metal particle P2 with a relatively small particle size, the effective portion 110 can have a relatively high fill rate of magnetic metal particles P1 and P2 compared to the first cover portion 121, the second cover portion 122, the third cover portion 123, and the fourth cover portion 124 (the first cover portion 121, the second cover portion 122, the third cover portion 123, and the fourth cover portion 124 only include the third magnetic metal particle P3 and the fourth magnetic metal particle P4, which have a relatively small particle size compared to the first magnetic metal particle P1). The term "filling rate of magnetic metal particles" can refer to the total volume or total mass occupied by magnetic metal particles within a unit volume (e.g., a unit volume of 10 μm length × 10 μm width × 10 μm thickness) of each of the effective portion 110 and the covering portions 121, 122, 123, and 124. Alternatively, the term "filling rate of magnetic metal particles" can refer to the total area occupied by magnetic metal particles within a unit area (e.g., a unit area of ​​10 μm length × 10 μm width) of a cross-section of each of the effective portion 110 and the covering portions 121, 122, 123, and 124. In the following description, for ease of description, the magnetic metal particles P1 and P2 of the effective portion 110 will be provided under the assumption that they consist only of a first magnetic metal particle P1 and a second magnetic metal particle P2 with different particle sizes; however, this disclosure is not limited thereto. For example, as another non-limiting example of this disclosure, the magnetic metal particles P1, P2, and P3 of the effective portion 110 may include three types of particles with different diameters.

[0042] The first cover portion 121 and the second cover portion 122 may be respectively provided on the upper and lower surfaces of the effective portion 110, which are opposite to each other in the thickness direction T. Typically, multiple individual components can be mass-produced by manufacturing a coil strip in which multiple main bodies are connected to each other, followed by separating the multiple main bodies from each other through a cutting process. In the case of a component in which one surface of the support substrate is set horizontally parallel to the mounting surface of the component, the cutting surface does not constitute the upper and lower surfaces of the main bodies in a single component. On the other hand, in the case of a component in which one surface of the support substrate is set vertically perpendicular to the mounting surface, the upper and lower surfaces of the main body correspond to the cutting surface formed by cutting. For this reason, at least a portion of the magnetic metal particles included in the main body can be cut by a cutting blade to expose the upper and lower surfaces of the main body. When an external electrode is formed by plating in this state, the magnetic metal particles cut to expose the conductive core may cause plating diffusion on the upper and lower surfaces of the main body, resulting in a short circuit of the external electrode. In this embodiment, the above problem can be solved by providing the first cover portion 121 and the second cover portion 122 on the upper and lower surfaces (cutting surfaces) of the effective portion 110. For example, in this embodiment, at least a portion of the first magnetic metal particle P1 and the second magnetic metal particle P2 can be cut, thus exposing the cut surface to the upper and lower surfaces of the effective portion 110 (in particular, the magnetic metal particle P1, which has a relatively large particle size, is often cut and thus exposed). A first covering portion 121 and a second covering portion 122, including the third magnetic metal particle P3 and the second insulating resin R2, can be respectively provided on the upper and lower surfaces of the effective portion 110 to cover the conductive cores of the magnetic metal particles exposed on the upper and lower surfaces of the effective portion 110. For example, the first covering portion 121 and the second covering portion 122 can cover the upper and lower surfaces of the effective portion 110 (the cut surface of the effective portion 110). For this reason, the conductive cores of the magnetic metal particles P1, P2, and P3 may not be exposed to the upper and lower surfaces of the body 100. Therefore, plating diffusion occurring on the upper and lower surfaces of the body 100 when the outer electrodes 410 and 420 are plated can be reduced. Since the first cover portion 121 and the second cover portion 122 include a third magnetic metal particle P3 with a diameter smaller than that of the first magnetic metal particle P1, the surface roughness of the surfaces of the first cover portion 121 and the second cover portion 122 can be reduced. The pad portions 411 and 421 and the strip portions 413 and 423 of the external electrodes 410 and 420, which will be described later, can be provided on the upper and lower surfaces of the body 100, and external defects of the external electrodes 410 and 420 can be reduced due to the relatively low surface roughness of the upper and lower surfaces of the body 100. Furthermore, the pad portions 411 and 421 and the strip portions 413 and 423 of the external electrodes can be formed uniformly. The diameter of the third magnetic metal particle P3 can be the same as the diameter of the second magnetic metal particle P2.In this case, the ease of the process can be improved. The second insulating resin R2 may be different from the first insulating resin R1. However, this disclosure is not limited to this, and for example, the first insulating resin R1 and the second insulating resin R2 may comprise the same resin (such as epoxy resin), thus improving the bonding strength between the effective portion 110 and the first cover portion 121 and the second cover portion 122. Since the curing of the effective portion 110 is completed when the first cover portion 121 and the second cover portion 122 are formed, an interface is formed between each of the first cover portion 121 and the second cover portion 122 and the effective portion 110. The first cover portion 121 and the second cover portion 122 may be formed by a sheet lamination method or a paste coating method, but this disclosure is not limited to this.

[0043] The third covering portion 123 and the fourth covering portion 124 may be respectively provided on two opposing surfaces of the effective portion 110 in the width direction W. For example, based on Figure 1In the direction of the effective portion 110, the third cover portion 123 may be disposed on the front surface of the effective portion 110 to form the third surface 103 of the main body 100, and the fourth cover portion 124 may be disposed on the rear surface of the effective portion 110 to form the fourth surface 104 of the main body 100. The third cover portion 123 and the fourth cover portion 124 may be formed by laminating a second magnetic composite sheet on the first magnetic composite sheet disposed at the outermost part in the width direction W after the process of laminating the first magnetic composite sheet for forming the effective portion 110. The second magnetic composite sheet includes a fourth magnetic metal particle P4 with a diameter smaller than the first magnetic metal particle P1 and a third insulating resin R3. In addition, the third cover portion 123 and the fourth cover portion 124 may be formed by laminating a second magnetic composite sheet including a fourth magnetic metal particle P4 with a diameter smaller than the first magnetic metal particle P1 and a third insulating resin R3. For example, a first magnetic composite sheet for forming the effective portion 110 and a second magnetic composite sheet for forming the third cover portion 123 and the fourth cover portion 124 can be stacked along the width direction W, so that the second magnetic composite sheet is disposed on the first magnetic composite sheet disposed at the outermost position in the width direction W. That is, unlike the first cover portion 121 and the second cover portion 122, the third cover portion 123 and the fourth cover portion 124 can be formed together with the effective portion 110 in the same process. Since the third cover portion 123 and the fourth cover portion 124 form the third surface 103 and the fourth surface 104 of the body 100, external defects of the body 100 can be reduced. The diameter of the fourth magnetic metal particle P4 can be the same as the diameter of the third magnetic metal particle P3 or the diameter of the second magnetic metal particle P2. The third insulating resin R3 can include the same resin as the first insulating resin R1, but this disclosure is not limited thereto. Due to the aforementioned process, the upper surface of the effective portion 110 can be coplanar with the upper surfaces of each of the third covering portion 123 and the fourth covering portion 124, and the lower surface of the effective portion 110 can also be coplanar with the lower surfaces of each of the third covering portion 123 and the fourth covering portion 124. Furthermore, due to the aforementioned process, at least a portion of the upper and lower surfaces of each of the third covering portion 123 and the fourth covering portion 124, which are coplanar with the upper and lower surfaces of the effective portion 110, can be covered.

[0044] Each of the first cover portion 121, the second cover portion 122, the third cover portion 123, and the fourth cover portion 124 may have a thickness of 20 μm to 30 μm. The thickness of the first cover portion 121 and the second cover portion 122 may refer to the length (dimension) of the first cover portion 121 and the second cover portion 122 in the thickness direction T, and the thickness of the third cover portion 123 and the fourth cover portion 124 may refer to the length (dimension) of the third cover portion 123 and the fourth cover portion 124 in the width direction W. For example, when the thickness of the first cover portion 121 is less than 20 μm, it may be difficult to ensure insulation between the external electrodes 410 and 420, and there is a possibility of a short circuit between the external electrodes 410 and 420. For example, when the thickness of the first cover portion 121 is greater than 30 μm, the thickness of the entire assembly may be increased.

[0045] Each of the magnetic metal particles P1, P2, P3, and P4 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, the magnetic metal particles may be one or more 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.

[0046] The magnetic metal particles P1, P2, P3, and P4 can be amorphous or crystalline. For example, the magnetic metal particles P1, P2, P3, and P4 can be Fe-Si-B-Cr based amorphous alloy particles, but are not limited thereto. Each of the magnetic metal particles P1, P2, P3, and P4 can have an average diameter of about 0.1 μm to about 30 μm, but is not limited thereto.

[0047] Each of the magnetic metal particles P1, P2, P3 and P4 may include a conductive core (the aforementioned material) and an insulating coating on the surface of the conductive core.

[0048] Each of the insulating resins R1, R2 and R3 may be, in a single form or in combination, epoxy resin, polyimide, liquid crystal polymer, etc., but is not limited thereto.

[0049] The main body 100 may have a core C passing through the support substrate 200 and the coil portion 300, which will be described later. The core C may be formed by filling the through holes of the coil portion 300 with a magnetic composite sheet, but this disclosure is not limited thereto.

[0050] A support substrate 200 may be disposed within the body 100 and may have a surface perpendicular to the lower surface (sixth surface) 106 of the body 100. The support substrate 200 may be configured to support the coil portion 300, which will be described later. As an example, the phrase "a surface of the support substrate 200 is perpendicular to the lower surface 106 of the body 100" may mean that a surface of the support substrate 200 forms an angle of 80 to 100 degrees with the lower surface 106 of the body 100, including the meaning of perpendicularity in a mathematical sense. As an example, the statement that element A (such as an object, plane, or line / direction) is perpendicular to or orthogonal to element B (such as another object, another plane, or another line / direction) may mean that element A and element B form an angle of 80 to 100 degrees, including the meaning of perpendicularity in a mathematical sense. In one example, the winding axis of the coil portion 300 may be parallel to the lower surface 106 of the body 100. As an example, the sentence "the winding axis of the coil section 300 may be parallel to the lower surface 106 of the body 100" can mean that the winding axis and the lower surface 106 of the body 100 form an angle of -10 degrees to 10 degrees, and also includes the meaning of parallelism in a mathematical sense. As an example, the statement that element C (such as an object, plane, or line / direction) is parallel to element D (such as another object, another plane, or another line / direction) can mean that element C and element D form an angle of -10 degrees to 10 degrees, and also includes the meaning of parallelism in a mathematical sense.

[0051] The support substrate 200 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 200 may include an insulating material formed by impregnating a reinforcing material such as glass fiber or inorganic filler in an insulating resin. For example, the support substrate 200 may include insulating materials such as prepreg, Ajinomoto build-up film (ABF), FR-4, bismaleimide triazine (BT) film, photosensitive dielectric (PID) film, copper clad laminate (CCL), etc., but this disclosure is not limited thereto.

[0052] Inorganic fillers may be selected from one or more of the group consisting of silicon dioxide (SiO2), aluminum oxide (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc, clay, mica particles, aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), magnesium carbonate (MgCO3), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO3), barium titanate (BaTiO3), and calcium zirconate (CaZrO3).

[0053] When the support substrate 200 is formed using an insulating material including reinforcing material, the support substrate 200 can provide higher rigidity. When the support substrate 200 is formed using an insulating material that does not include glass fiber, the support substrate 200 is advantageous for making the coil assembly 1000 thinner. Additionally, the effective volume of the coil portion 300 and / or magnetic material can be increased based on the same volume of the assembly, thereby improving the assembly characteristics. When the support substrate 200 is formed using an insulating material including a photosensitive insulating resin, the number of processes used to form the coil portion 300 can be reduced. Therefore, this can be advantageous in terms of reducing production costs, and fine vias can be formed.

[0054] The coil portion 300 may be disposed on at least one surface of the support substrate 200. The coil portion 300 may be embedded in the body 100 to exhibit the characteristics of the coil assembly 1000. For example, when the coil assembly 1000 is used as a power inductor, the coil portion 300 may store an electric field as a magnetic field to maintain the output voltage for stabilizing the power of electronic devices.

[0055] The coil portion 300 may be formed on at least one of the two opposing surfaces of the support substrate 200, and may form at least one turn. The coil portion 300 may be disposed on one surface and the other surface of the support substrate 200 that are opposing each other in the width direction W.

[0056] The coil portion 300 may include coil patterns 311 and 312, a via 321, and lead-out patterns 331 and 332. Specifically, each of the first coil pattern 311 and the second coil pattern 312 may be in the form of a planar spiral in which at least one turn is formed around the core C. For example, based on Figure 1 In the direction of the first coil pattern 311, at least one turn may be formed around the core C on the rear surface of the support substrate 200. At least one turn may be formed around the core C on the front surface of the support substrate 200. A first lead-out pattern 331 may be disposed on the rear surface of the support substrate 200 to connect to the first coil pattern 311 and expose the first surface 101 of the body 100. A second lead-out pattern 332 may be disposed on the front surface of the support substrate 200 to connect to the second coil pattern 312 and expose the second surface 102 of the body 100. A through-hole 321 may penetrate the support substrate 200 to connect the innermost ends of the first coil pattern 311 and the second coil pattern 312 to each other. Therefore, the coil portion 300 can be used as a single coil integrally connected.

[0057] At least one of the coil patterns 311 and 312, the via 321, and the lead-out patterns 331 and 332 may include at least one conductive layer.

[0058] As an example, when the second coil pattern 312, via 321, and second lead-out pattern 332 are formed by plating on the support substrate 200, each of the second coil pattern 312, via 321, and second lead-out pattern 332 may include a seed layer and an electroplated layer. The seed layer may be formed by electroless plating or vapor deposition (such as sputtering). Each of the seed layer and the electroplated layer may have a single-layer structure or a multi-layer structure. An electroplated layer with a multi-layer structure may be formed as a conformal film structure in which one electroplated layer is covered by another electroplated layer or as a stacked structure in which another electroplated layer is only stacked on one surface of an electroplated layer. It may be formed in a certain shape. The seed layer of the second coil pattern 312, the seed layer of the via 321, and the seed layer of the second lead-out pattern 332 may be formed integrally with each other so that no boundary is formed between them, but this disclosure is not limited thereto. The electroplated layers of the second coil pattern 312, the via 321, and the second lead-out pattern 332 may be formed as an integral part of each other, such that no boundary is formed between them, but this disclosure is not limited thereto.

[0059] Each of the coil patterns 311 and 312, the via 321, and the lead-out patterns 331 and 332 may include a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), chromium (Cr), molybdenum (Mo), or alloys thereof, but this disclosure is not limited thereto.

[0060] In this embodiment, since the coil portion 300 is configured perpendicular to the sixth surface 106 (mounting surface) of the main body 100, the mounting area can be reduced while maintaining the volume of the main body 100. Therefore, a greater number of electronic components can be mounted on a mounting plate with the same area. Furthermore, since the coil portion 300 is configured perpendicular to the sixth surface 106 (mounting surface) of the main body 100, the direction of the magnetic flux induced by the coil portion 300 can be set parallel to the sixth surface 106 of the main body 100. For this reason, noise introduced to the mounting surface of the mounting plate can be relatively reduced.

[0061] An insulating layer IF may be provided to insulate the coil portion 300 from the body 100, and the insulating layer IF may include known insulating materials such as parylene, but this disclosure is not limited thereto. The insulating layer IF may be formed by vapor deposition. However, this disclosure is not limited thereto, and the insulating layer IF may also be formed by laminating insulating films on both surfaces of the support substrate 200.

[0062] When the coil assembly 1000 is mounted on a printed circuit board (PCB) or the like, the external electrodes 410 and 420 can electrically connect the coil assembly 1000 according to this embodiment to the PCB or the like. As an example, the coil assembly 1000 can be mounted such that the sixth surface 106 of the body 100 faces the upper surface of the PCB, and the external electrodes 410 and 420, which are spaced apart from each other on the sixth surface 106 of the body 100, can be electrically connected to the connection portion of the PCB.

[0063] External electrodes 410 and 420 can be connected to lead-out patterns 331 and 332, respectively, which extend to the first surface 101 and the second surface 102 of the body 100, respectively. Specifically, the first external electrode 410 may include: a first pad portion 411 disposed on the sixth surface 106 of the body 100; a first extension portion 412 extending from the first pad portion 411 to the first surface 101 of the body 100; and a first strip portion 413 extending from the first extension portion 412 to the fifth surface 105 of the body 100. The first extension portion 412 can contact and connect with the first lead-out pattern 331 exposed on the first surface 101 of the body 100. The second external electrode 420 may include: a second pad portion 421 disposed on a sixth surface 106 of the body 100; a second extension portion 422 extending from the second pad portion 421 to a second surface 102 of the body 100; and a second strip portion 423 extending from the second extension portion 422 to a fifth surface 105 of the body 100. The second extension portion 422 may contact and connect with a second lead-out pattern 332 exposed on the second surface 102 of the body 100. For example, each of the first external electrode 410 and the second external electrode 420 may be formed to have an integral "U" shape. For example, each of the pad portions 411 and 421 and the strip portions 413 and 423 may have a thickness of 20 μm, and each of the extension portions 412 and 422 may have a thickness of 30 μm, but this disclosure is not limited thereto. The phrase "thickness of each of pad portions 411 and 421 and strip portions 413 and 423" can refer to the length (dimension) of each of pad portions 411 and 421 and strip portions 413 and 423 in the thickness direction T. The phrase "thickness of each of extension portions 412 and 422" can refer to the length (dimension) of each of extension portions 412 and 422 in the length direction L.

[0064] The external electrodes 410 and 420 may be formed using conductive materials such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or alloys thereof, but this disclosure is not limited thereto.

[0065] Each of the external electrodes 410 and 420 may be formed having a multilayer structure. For example, each of the external electrodes 410 and 420 may include a first metal layer disposed on the body 100, a second metal layer disposed on the first metal layer, and a third metal layer disposed on the second metal layer. The first metal layer may be formed by vapor deposition (such as sputtering), electroplating, or paste coating methods. A paste coating method refers to a method of applying a conductive paste comprising conductive particles (such as copper (Cu) and / or silver (Ag)) and a thermosetting resin to the surface of the body 100 and then curing it. Each of the second and third metal layers may be formed by electroplating. As a non-limiting example, the first metal layer may be a copper plating, the second metal layer may be a nickel plating, and the third metal layer may be a tin plating, but this disclosure is not limited thereto.

[0066] In this disclosure, the average size of the metal particles dispersed in the portion of the body 100 that contacts one of the pad portions may be smaller than the average size of the metal particles dispersed in another portion of the body 100 spaced apart from the outer surface of the body 100, and the metal particles in said other portion of the body 100 may include flat surfaces and curved surfaces intersecting with flat surfaces. Furthermore, the average size of the metal particles dispersed in the portion of the body 100 that contacts one of the strip portions may be smaller than the average size of the metal particles dispersed in another portion of the body 100 spaced apart from the outer surface of the body 100. Additionally, the average size of the metal particles dispersed in the portion of the body 100 that contacts one of the extension portions may be smaller than the average size of the metal particles dispersed in another portion of the body 100 spaced apart from the outer surface of the body 100.

[0067] Therefore, the coil assembly 1000 according to this embodiment can prevent plating diffusion on the upper and lower surfaces of the main body 100, thereby preventing short circuits between the outer electrodes 410 and 420 when they are plating. Furthermore, the first cover portion 121 is provided on the upper surface of the effective portion 110 to significantly reduce the distance between the upper surface of the effective portion 110 and the coil portion 300, thus reducing the overall thickness of the assembly, while also ensuring the edge distance of the assembly in the thickness direction T.

[0068] Figure 4 This is a schematic perspective view of another coil assembly according to an exemplary embodiment. Figure 5 It is along Figure 4 The cross-sectional view taken from line III-III', and Figure 6 It is along Figure 4 A cross-sectional view taken from line IV-IV'. For ease of description, in Figure 5 In the middle, based on along Figure 4 The cross-section taken from line III-III' shows the internal structure of the coil assembly.

[0069] Reference Figures 1 to 3 and Figures 4 to 6 The differences between the coil assembly 2000 according to this embodiment and the coil assembly 1000 according to an exemplary embodiment exist in the first cover portion 121, the second cover portion 122, and the outer electrodes 410 and 420. Therefore, this embodiment will be described with only the first cover portion 121, the second cover portion 122, and the outer electrodes 410 and 420 in mind. The description of other components in the previous exemplary embodiment can be equivalently applied to other components in this embodiment.

[0070] Reference Figures 4 to 6 The first cover portion 121 and the second cover portion 122 applied to the coil assembly 2000 according to this embodiment may be provided only on a portion of each of the upper and lower surfaces of the effective portion 110 in the longitudinal direction L. Specifically, the first cover portion 121 extends continuously between the edges in the width direction W of the upper surface of the effective portion 110, but does not cover the two ends of the upper surface of the effective portion 110 in the longitudinal direction L, because the first cover portion 121 is only provided in the central portion of the upper surface of the effective portion 110 in the longitudinal direction L. The second cover portion 122 extends continuously between the edges in the width direction W of the lower surface of the effective portion 110, but does not cover the two ends of the lower surface of the effective portion 110 in the longitudinal direction L, because the second cover portion 122 is only provided in the central portion of the lower surface of the effective portion 110 in the longitudinal direction L. As a result, the pad portions 411 and 421 and the strip portions 413 and 423 of the external electrodes 410 and 420 contact the lower and upper surfaces of the effective portion 110, respectively. For example, the first cover 121 may only cover the space between the strip portions 413 and 423 on the upper surface of the effective portion 110, and the second cover 122 may only cover the space between the pad portions 411 and 421 on the lower surface of the effective portion 110. In this embodiment, since the first cover 121 and the second cover 122 are only provided in some areas of the upper and lower surfaces of the effective portion 110, the overall thickness of the component can be reduced. In addition, since the first cover 121 and the second cover 122 are respectively provided in the space between the strip portions 413 and 423 and in the space between the pad portions 411 and 421, short circuits between the external electrodes 410 and 420 can be prevented when the external electrodes 410 and 420 are formed by the plating process.

[0071] Figure 7 This is a schematic perspective view of another coil assembly according to an exemplary embodiment. Figure 8 It is along Figure 7 The cross-sectional view taken by line V-V', and Figure 9 It is along Figure 7A cross-sectional view taken from line VI-VI'. For ease of description, in Figure 8 In the middle, based on along Figure 7 The cross-section taken by line V-V' shows the internal structure of the coil assembly.

[0072] Reference Figures 1 to 3 and Figures 7 to 9 The difference between the coil assembly 3000 according to this embodiment and the coil assembly 1000 according to an exemplary embodiment lies in the lead-out patterns 331 and 332. Therefore, this embodiment will be described with only focus on lead-out patterns 331 and 332. Other descriptions of the exemplary embodiments may be equivalent.

[0073] Reference Figures 7 to 9 In the coil portion 300 of the coil assembly 3000 according to this embodiment, lead-out patterns 331 and 332 may be exposed on the lower surface of the active portion 110. Specifically, the first lead-out pattern 331 and the second lead-out pattern 332 may be exposed on the lower surface of the active portion 110 in a spaced-apart manner, but may not be exposed on other surfaces of the body 100. Therefore, the lower electrode structure of the coil assembly 3000 according to this embodiment can be easily realized.

[0074] In this embodiment, the external electrodes 410 and 420 are formed to have, for example, an integral L-shape, such as... Figures 7 to 9 As shown. Specifically, the first external electrode 410 may include: a first pad portion 411 disposed on the lower surface of the effective portion 110; and a first extension portion 412 extending from the first pad portion 411 to the first surface 101 of the body 100. The second external electrode 420 may include: a second pad portion 421 disposed on the lower surface of the effective portion 110; and a second extension portion 422 extending from the second pad portion 421 to the second surface 102 of the body 100. However, due to Figures 7 to 9 The shapes of the external electrodes 410 and 420 shown are merely exemplary, and therefore this disclosure is not limited thereto. Furthermore, the first cover 121 may cover the entire upper surface of the effective portion 110, and each of the first extension 412 and the second extension 422 may contact the side surface of the first cover 121, but may not extend to the upper surface of the first cover 121.

[0075] As described above, a coil assembly in which the coil portion is configured perpendicular to the lower surface of the body can easily prevent short circuits between the external electrodes.

[0076] In addition, the coil assembly in which the coil section is set perpendicular to the lower surface of the main body can increase the effective volume of the magnetic material.

[0077] Although exemplary embodiments have been shown and described above, it will be readily understood by 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: The body has an upper surface and a lower surface that are opposite to each other in the thickness direction of the body; A support substrate is disposed in the main body and has a surface perpendicular to the lower surface of the main body; A coil portion is disposed on at least one surface of the support substrate; as well as The first and second external electrodes are disposed spaced apart from each other on the lower surface of the main body and are respectively connected to the coil portion. The main body includes an effective portion, a first covering portion, and a second covering portion. The effective portion covers the coil portion. The first covering portion and the second covering portion are respectively disposed on the upper and lower surfaces of the effective portion, which are opposite to each other in the thickness direction. The effective part includes a first magnetic metal particle, a second magnetic metal particle, and a first insulating resin. The diameter of the second magnetic metal particle is smaller than the diameter of the first magnetic metal particle. Each of the first and second covering portions includes a third magnetic metal particle and a second insulating resin, wherein the diameter of the third magnetic metal particle is smaller than the diameter of the first magnetic metal particle. The main body further includes a third covering portion and a fourth covering portion, which are respectively disposed on two opposite side surfaces of the effective portion in the width direction of the main body. Each of the third and fourth covering portions includes a fourth magnetic metal particle and a third insulating resin, wherein the diameter of the fourth magnetic metal particle is smaller than the diameter of the first magnetic metal particle.

2. The coil assembly according to claim 1, wherein, At least a portion of the first magnetic metal particle is cut into a surface exposed to one of the upper and lower surfaces of the effective portion.

3. The coil assembly according to claim 1, wherein, The second magnetic metal particle and the third magnetic metal particle have the same diameter.

4. The coil assembly according to claim 1, wherein, The fourth magnetic metal particle and the third magnetic metal particle have the same diameter.

5. The coil assembly according to claim 1, wherein, The first covering portion extends from the upper surface of the effective portion to cover at least a portion of the upper surface of each of the third and fourth covering portions, and the second covering portion extends from the lower surface of the effective portion to cover at least a portion of the lower surface of each of the third and fourth covering portions.

6. The coil assembly according to claim 5, wherein, The upper surface of the effective part is coplanar with the upper surfaces of each of the third and fourth covering parts.

7. The coil assembly according to claim 1, wherein, The body also has one end surface and another end surface that are opposite to each other along the length direction of the body, and The first external electrode and the second external electrode each include a pad portion, an extension portion and a strip portion. The pad portions are disposed on the lower surface of the effective portion or the second covering portion at intervals from each other. The extension portions extend from the pad portions to one end surface and the other end surface of the body, respectively. The strip portions are disposed on the upper surface of the effective portion or the first covering portion at intervals from each other.

8. The coil assembly according to claim 7, wherein, The first covering portion and the second covering portion respectively cover the entire upper surface and the entire lower surface of the effective portion, and The strip portion and the pad portion are respectively disposed on the first cover portion and the second cover portion.

9. The coil assembly according to claim 7, wherein, The strip portion contacts the upper surface of the effective portion, and the pad portion contacts the lower surface of the effective portion. The first covering portion is disposed in the space between the strip portions on the upper surface of the effective portion, and the second covering portion is disposed in the space between the pad portions on the lower surface of the effective portion.

10. The coil assembly according to claim 5, wherein, The body also has one end surface and another end surface that are opposite to each other along the length direction of the body. The first external electrode and the second external electrode each include a pad portion and an extension portion. The pad portions are disposed on the lower surface of the effective portion at intervals from each other, and the extension portions extend to one end surface and the other end surface of the main body, respectively. Each of the pad portions is in contact with the lower surface of the effective portion. The second covering portion is disposed in the space between the pad portions on the lower surface of the effective portion. The first covering portion covers the entire upper surface of the effective portion, and Each of the extensions contacts the side surface of the first cover and does not extend to the upper surface of the first cover.

11. A coil assembly, comprising: The main body has a lower surface; A support substrate is disposed in the main body and has a surface perpendicular to the lower surface of the main body; as well as A coil portion is disposed on at least one surface of the support substrate. The main body includes an effective portion and a first covering portion, a second covering portion, a third covering portion, and a fourth covering portion. The effective portion covers the coil portion. The first covering portion, the second covering portion, the third covering portion, and the fourth covering portion are respectively disposed on the upper surface of the effective portion, the lower surface of the effective portion, one side surface of the effective portion, and the other side surface of the effective portion. Each of the effective portion, the first covering portion, the second covering portion, the third covering portion, and the fourth covering portion includes magnetic metal particles and insulating resin, and The filling rate of the magnetic metal particles in the effective portion is greater than the filling rate of the magnetic metal particles in each of the first covering portion, the second covering portion, the third covering portion, and the fourth covering portion.

12. The coil assembly of claim 11, wherein, The first covering portion has a boundary with the upper surface of the effective portion, and the second covering portion has a boundary with the lower surface of the effective portion. At least a portion of the magnetic metal particles in the effective part are cut to expose the boundary.

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