Magnetic assembly

Abstract

The invention provides a magnetic assembly. The magnetic assembly comprises a magnetic body, the magnetic body comprises a plurality of first magnetic particles and a plurality of second magnetic particles, the plurality of first magnetic particles comprise a Fe component, and the plurality of second magnetic particles comprise a Fe component. The average particle size of the plurality of second magnetic particles is smaller than that of the plurality of first magnetic particles, a first layer is formed on the outer surface of at least one first magnetic particle in the plurality of first magnetic particles, and a second layer is formed on the outer surface of the first layer; a first layer is formed on an outer surface of at least one of the plurality of second magnetic particles, the first layer of the at least one first magnetic particle includes an Fe oxide, and the second layer of the at least one first magnetic particle includes an Si oxide, and the first layer of the at least one second magnetic particle includes a P oxide.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0087183, filed on July 2, 2024, with the Korean Intellectual Property Office, and Korean Patent Application No. 10-2024-0201144, filed on December 30, 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 magnetic component. Background Technology

[0003] As electronic devices such as digital televisions, mobile phones, and laptops become smaller and thinner, the magnetic components used in these devices also need to be smaller and thinner, and various types of magnetic components are being used to meet these requirements. Examples of magnetic components include inductors containing coils, and research and development on coil-type inductors or thin-film inductors are actively underway.

[0004] The main challenge in miniaturizing and thinning magnetic components is maintaining properties equivalent to existing components despite achieving such miniaturization and thinning. To meet these requirements, the ratio of magnetic material in the core must be increased; however, increasing this ratio is limited by factors such as changes in frequency characteristics due to the insulation of the magnetic body.

[0005] As an example of manufacturing magnetic components, a method has been used where sheets comprising a mixture of magnetic particles and resin, etc., are laminated and then pressed to form the body. Here, ferrite or metal, etc., can be used as the magnetic particles. When using magnetic metal particles, increasing the particle content is advantageous in terms of the magnetic permeability characteristics of the magnetic component, etc., but in this case, the insulation of the magnetic body may deteriorate, and eddy current losses may occur. Therefore, in the art, it is necessary to ensure sufficient surface insulation of the magnetic particles to prevent deterioration of the properties of the magnetic component. Summary of the Invention

[0006] One aspect of this disclosure is to improve the characteristics of magnetic components by improving the eddy current loss characteristics and structural stability of the magnetic body, including magnetic particles.

[0007] According to one aspect of this disclosure, a magnetic component includes a magnetic body, wherein the magnetic body includes a plurality of first magnetic particles and a plurality of second magnetic particles, the plurality of first magnetic particles comprising Fe, the plurality of second magnetic particles comprising Fe, and the average particle size of the plurality of second magnetic particles being smaller than the average particle size of the plurality of first magnetic particles, a first layer being formed on the outer surface of at least one of the plurality of first magnetic particles, a second layer being formed on the outer surface of the first layer, and a first layer being formed on the outer surface of at least one of the plurality of second magnetic particles, the first layer of the at least one first magnetic particle comprising Fe oxide, the second layer of the at least one first magnetic particle comprising Si oxide, and the first layer of the at least one second magnetic particle comprising P oxide.

[0008] The average particle size of the first magnetic particle can be from 15 μm to 35 μm.

[0009] The average thickness of the second layer of the at least one first magnetic particle can be from 5 nm to 35 nm.

[0010] The first layer of the at least one first magnetic particle may include less than 1 wt% Si content relative to the total amount of the first layer of the at least one first magnetic particle.

[0011] The second layer of the at least one first magnetic particle may comprise 30 wt% to 70 wt% Si content relative to the total amount of the second layer of the at least one first magnetic particle.

[0012] The second layer of the at least one first magnetic particle may not include Sn and / or P components.

[0013] The average particle size of the second magnetic particle can be from 0.9 μm to 4.5 μm.

[0014] The average thickness of the first layer of the at least one second magnetic particle can be from 5 nm to 15 nm.

[0015] The first layer of the at least one second magnetic particle may include phosphate.

[0016] A third layer may be formed on the outer surface of the second layer of the at least one first magnetic particle.

[0017] The third layer may include a compound having at least one functional group selected from the group consisting of alkyl, carbonyl, and polyurethane acrylate.

[0018] The average thickness of the third layer can be less than 10 nm.

[0019] The first magnetic particle may include an Fe-Si-Cr based alloy.

[0020] The magnetic body may further include a plurality of third magnetic particles, the plurality of third magnetic particles comprising Fe, and the average particle size of the plurality of third magnetic particles being smaller than the average particle size of the plurality of second magnetic particles.

[0021] The average particle size of the third magnetic particle can be from 5 nm to 800 nm.

[0022] According to another aspect of this disclosure, a magnetic component includes: a magnetic body, wherein the magnetic body includes a plurality of first magnetic particles and a plurality of second magnetic particles, the plurality of first magnetic particles comprising Fe, the plurality of second magnetic particles comprising Fe, and the average particle size of the plurality of second magnetic particles being smaller than the average particle size of the plurality of first magnetic particles, a first layer being formed on the outer surface of at least one of the plurality of first magnetic particles, a second layer being formed on the outer surface of the first layer, a first layer being formed on the outer surface of at least one of the plurality of second magnetic particles, the first layer of the at least one first magnetic particle comprising Fe oxide, the second layer of the at least one first magnetic particle being substantially free of Fe oxide, and no second layer being formed on the outer surface of the first layer of the at least one second magnetic particle. Attached Figure Description

[0023] The above and other aspects, features and advantages of this disclosure will become clearer from the following detailed embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic perspective view illustrating a magnetic component according to an embodiment of the present disclosure; Figure 2 yes Figure 1 A cross-sectional view of the magnetic component; Figure 3 yes Figure 1 A magnified view of a local area of ​​the magnetic body in the magnetic component; Figure 4 A second magnetic particle that can be used in a magnetic assembly is shown; Figure 5 A first magnetic particle that can be used in a magnetic assembly is shown; Figure 6 It is an enlarged view of a local area of ​​the magnetic body of the magnetic component according to the variant example; Figure 7 A third magnetic particle that can be used in magnetic components is shown; Figure 8 This is a schematic perspective view showing a magnetic component according to another embodiment of the present disclosure; Figure 9 yes Figure 8 A schematic exploded perspective view of the magnetic components; and Figure 10 yes Figure 8 A cross-sectional view of the magnetic component. Detailed Implementation

[0024] In the following, exemplary embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. However, the inventive concept can be exemplified in many different forms and should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, the shape and size of elements may be exaggerated for clarity, and the same reference numerals will always be used to denote the same or similar elements.

[0025] Electronic devices use various types of electronic components, and various types of magnetic components can be appropriately used among these electronic components for purposes such as noise removal. That is, magnetic components in electronic devices can be used as power inductors, high-frequency inductors (HF inductors), ordinary ferrite beads, high-frequency ferrite beads (e.g., ferrite beads suitable for the GHz band), common-mode filters, etc.

[0026] Figure 1 This is a schematic perspective view illustrating a magnetic component according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A cross-sectional view of the magnetic component. Figure 3 yes Figure 1 A magnified view of a local area of ​​the magnetic body in the magnetic component. Figure 4 A second magnetic particle that can be used in a magnetic component is shown.

[0027] Reference Figures 1 to 4According to this embodiment, the magnetic component 100 may include a magnetic body 101, which includes a plurality of magnetic particles, and the plurality of magnetic particles may include a plurality of first magnetic particles 111 and a plurality of second magnetic particles 121. Here, the average particle size d2 of the plurality of second magnetic particles 121 may be smaller than the average particle size d1 of the plurality of first magnetic particles 111. Furthermore, a first layer 112 may be formed on the outer surface of at least one of the plurality of first magnetic particles 111, and a second layer 113 may be formed on the outer surface of the first layer 112. In some embodiments, a first layer 122 may be formed on the outer surface of at least one of the plurality of second magnetic particles 121. In this embodiment, the first magnetic particles 111 and the second magnetic particles 121, which have different average particle sizes from each other, may have different insulating structures formed on their respective surfaces. Specifically, the first layer 112 of the first magnetic particles 111 may include Fe oxide, and the second layer 113 of the first magnetic particles 111 may include Si oxide. Furthermore, the first layer 122 of the second magnetic particles 121 may include P oxide. The first magnetic particles 111, having a relatively large particle size, can significantly influence the insulation properties of the magnetic body 101, and the insulation properties of the first magnetic particles 111 can be increased through the insulation structure of the first layer 112 and the second layer 113 (particularly the second layer 113 comprising Si oxide). Furthermore, when the second magnetic particles 121 have a relatively small particle size, multiple second magnetic particles 121 will exhibit a large specific surface area; therefore, an insulating layer with excellent wettability to the insulating material 110 of the magnetic body 101, i.e., a first layer 122 comprising P oxide, is used. With this insulation structure, the magnetic body 101 can have improved eddy current loss characteristics, structural stability, etc. The main components constituting the magnetic assembly 100 of this embodiment will be described below.

[0028] The magnetic body 101 forms the exterior of the magnetic assembly 100, and the coil 103 and the support member 102 supporting the coil 103 can be arranged inside the magnetic body. Figure 3As shown, the first magnetic particle 111 and the second magnetic particle 121 can be dispersed within the insulating material 110. The insulating material 110 may include dispersants, adhesives, etc., and may include, for example, polymer components such as epoxy resin or polyimide. The magnetic body 101 may be integrally formed in a hexahedral shape. According to some embodiments, the magnetic assembly 100, wherein the external electrodes 105 and 106 are disposed on the magnetic body 101, may have a length of 2.5 mm, a width of 2.0 mm, and a thickness of 1.0 mm, or a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.65 mm, or a length of 1.6 mm, a width of 0.8 mm, and a thickness of 0.8 mm, or a length of 1.0 mm, a width of 0.5 mm, and a thickness of 0.5 mm, or a length of 0.8 mm, a width of 0.4 mm, and a thickness of 0.65 mm, but is not limited thereto. In addition, the foregoing values ​​are merely design values ​​that do not reflect process errors, etc., and therefore, the range that can be identified as process errors should be considered to fall within the scope of this disclosure.

[0029] The length of the magnetic component 100 in the first direction D1 can refer to the maximum value among multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the first direction D1, as shown in the cross-sectional photograph of the magnetic component 100 at the center of the second direction D2 in the first direction D1-third direction D3, based on an optical microscope photograph or scanning electron microscope (SEM) photograph. Alternatively, the length of the magnetic component 100 in the first direction D1 can refer to the minimum value among multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the first direction D1, as shown in the cross-sectional photograph. Alternatively, the length of the magnetic component 100 in the first direction D1 can refer to the arithmetic mean of the dimensions of at least three line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the first direction D1, as shown in the cross-sectional photograph. Here, multiple line segments parallel to the first direction D1 can be equidistant from each other on the third direction D3, but the scope of this disclosure is not limited thereto.

[0030] The second direction D2 length of the aforementioned magnetic component 100 can refer to the maximum value among multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the second direction D2, as shown in the cross-sectional photograph taken at the center of the first direction D1-second direction D2 in the third direction D3 of the magnetic component 100, based on an optical microscope or scanning electron microscope (SEM) photograph. Alternatively, the second direction D2 length of the aforementioned magnetic component 100 can refer to the minimum value among multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the second direction D2, as shown in the cross-sectional photograph. Alternatively, the second direction D2 length of the aforementioned magnetic component 100 can refer to the arithmetic mean of the dimensions of at least three line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the second direction D2, as shown in the cross-sectional photograph. Here, multiple line segments parallel to the second direction D2 can be equidistant from each other in the first direction D1, but the scope of this disclosure is not limited thereto.

[0031] The third-direction D3 length of the aforementioned magnetic component 100 can refer to: the maximum value among the dimensions of multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the third-direction D3, parallel to the third-direction D3 and shown in the cross-sectional photograph, based on an optical microscope or scanning electron microscope (SEM) photograph of the cross-section of the magnetic component 100 at the center of the second direction D2 in the first direction D1-third-direction D3. Alternatively, the aforementioned third-direction D3 length of the magnetic component 100 can refer to the minimum value among the dimensions of multiple line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the third-direction D3, parallel to the third-direction D3 and shown in the cross-sectional photograph. Alternatively, the aforementioned third-direction D3 length of the magnetic component 100 can refer to the arithmetic mean of the dimensions of at least three line segments connecting the two outermost boundary lines of the magnetic component 100 facing each other in the third-direction D3, parallel to the third-direction D3 and shown in the cross-sectional photograph. Here, multiple line segments parallel to the third direction D3 can be equidistant from each other in the first direction D1, but the scope of this disclosure is not limited thereto.

[0032] Furthermore, the lengths of each of the magnetic components 100 in the first direction D1 to the third direction D3 can be measured using a micrometer. The micrometer measurement method can be performed by setting the zero point with a metrological R&R (repeatability and reproducibility) micrometer, inserting the magnetic component 100 according to this embodiment between the tips of the micrometer, and rotating the measuring rod of the micrometer. Additionally, when measuring the length of the magnetic component 100 using the micrometer measurement method, the length of the magnetic component 100 can refer to a single measurement or the arithmetic mean of multiple measurements.

[0033] Reference Figure 3The magnetic body 101 includes a plurality of first magnetic particles 111 containing Fe and a plurality of second magnetic particles 121 containing Fe. To reduce eddy current losses, a first layer 112 may be formed on the outer surface of at least one of the first magnetic particles 111, a second layer 113 may be formed on the outer surface of the first layer 112, and a first layer 122 may be formed on the outer surface of at least one of the second magnetic particles 121. The plurality of first magnetic particles 111 may have an average particle size d1 of about 15 μm to about 35 μm. Furthermore, the plurality of second magnetic particles 121 may have an average particle size d2 of about 0.9 μm to about 4.5 μm. The average particle size d1 of the first magnetic particles 111 and the average particle size d2 of the second magnetic particles 121 can be obtained, for example, from an image of a cross-section of the magnetic body 101. As a specific example, a scanning electron microscope can be used to image a cross-section of the magnetic body 101 cut in the middle along the second direction D2, in the first direction-third direction (D1-D3). An image analysis program can then be used, and the average particle size d1 can be the average value for five or more first magnetic particles 111, and the average particle size d2 can be the average value for five or more second magnetic particles 121. Furthermore, the average particle size d1 of the first magnetic particles 111 and the average particle size d2 of the second magnetic particles 121 can be the major axis lengths of the respective magnetic particles 111 and 121. However, in some cases, the area of ​​the magnetic particles 111 and 121 can be calculated from the cross-section of the magnetic body 101 and then converted into the equivalent circle diameter. In this case, since the outer region of the magnetic body 101 may be deformed by processes such as pressing, the average particle sizes d1 and d2 of the first magnetic particles 111 and the second magnetic particles 121 can be measured excluding the outer region of the magnetic body 101. For example, regions corresponding to dimensions (e.g., length and / or thickness in a cross section) within 5% or 10% of the dimensions of the magnetic body (e.g., length and / or thickness in a cross section) from the surface of the magnetic body 101 can be excluded. The average particle size d1 of the first magnetic particle 111 and the average particle size d2 of the second magnetic particle 121 may not be obtained from only one cross section of the magnetic body 101, and can be calculated by averaging multiple values ​​obtained from multiple cross sections. Here, multiple cross sections of the magnetic body 101 may be taken at regular intervals in one direction. This measurement method using cross-sectional images of the magnetic body 101 can also be applied to the diameter of the third magnetic particle, the thickness of the surface insulating film (i.e., the first layer 112, the second layer 113, and the first layer 122, etc.), uniformity, etc., as described below.

[0034] According to some embodiments, the magnetic body 101 can be formed by a lamination method. Specifically, coils 103 can be formed on a support member 102 using methods such as plating, and then multiple unit laminates for manufacturing the magnetic body 101 can be prepared and laminated. Here, the unit laminates can be manufactured by mixing magnetic particles 111 such as metal, organic substances such as thermosetting resins, adhesives, and solvents to prepare a slurry, coating the slurry onto a carrier film at a thickness of tens of μm using a doctor blade, and then drying it to manufacture a sheet. Thus, the unit laminates can be manufactured in the form of magnetic particles dispersed in a thermosetting resin (e.g., epoxy resin or polyimide). Furthermore, the first magnetic particle 111 and the second magnetic particle 121 can have the above-described form, and the first layer 112 and the second layer 113 can be formed on the surface of the first magnetic particle 111, and the first layer 122 can be formed on the surface of the second magnetic particle 121. The aforementioned unit stack can be formed in multiple forms and pressed and stacked on the upper and lower sides of the coil 103 to realize the magnetic body 101.

[0035] The support member 102 can support the coil 103 and can be formed using polypropylene glycol (PPG), ferrite, or metal-based soft magnetic components. For example... Figure 2 As shown, the central portion of the support member 102 can be penetrated to form a through hole, and the through hole can be filled with magnetic particles to form a magnetic core portion C.

[0036] The coil 103 may be disposed inside the magnetic body 101 and may perform various functions within an electronic device. For example, the magnetic component 100 may be a power inductor, in which case the coil 103 may store electricity in the form of a magnetic field to maintain the output voltage and stabilize the power. In this case, the coil 103 may be stacked on each of the opposite sides of the support member 102 and may be electrically connected via conductive vias V penetrating the support member 102. The coil 103 may be formed in a helical shape, and the outermost portion of the helix may include an outlet L exposed to the outside of the magnetic body 101 for electrical connection with external electrodes 105 and 106.

[0037] Coil 103 is disposed on the first surfaces of the support member 102 that are opposite to each other. Figure 2 The upper surface and the second surface Figure 2At least one of the lower surfaces of the support member 102. As in this embodiment, the first coil 103a and the second coil 103b may be arranged on the first surface and the second surface of the support member 102, respectively, and in this case, the coil 103 may include a pad P. However, unlike this, the coil 103 may be disposed on only one surface of the support member 102. In addition, the coil pattern forming the coil 103 may be formed using plating processes used in the art (such as pattern plating, anisotropic plating, or isotropic plating), and multiple of these processes may be used to form the coil pattern forming the coil 103 into a multilayer structure.

[0038] External electrodes 105 and 106 may be formed on the outer surface of the magnetic body 101 and connected to the lead-out portion L. External electrodes 105 and 106 may be formed using a paste comprising a metal with excellent conductivity, and for example, the paste may be a conductive paste comprising individual nickel (Ni), copper (Cu), tin (Sn), or silver (Ag), or alloys thereof. Additionally, a plating layer may be further formed on the external electrodes 105 and 106. In this case, the plating layer may include at least one selected from the group consisting of nickel (Ni), copper (Cu), and tin (Sn), and for example, a nickel (Ni) layer and a tin (Sn) layer may be formed sequentially. Figure 1 In the middle, each of the external electrodes 105 and 106 may have the form of extending from one side surface of the magnetic body 101 to the upper surface, the lower surface and the remaining side surface (the surfaces opposite each other on the third direction D3), but may also be implemented in various shapes, for example, may have an L shape.

[0039] The plurality of first magnetic particles 111 and the plurality of second magnetic particles 121 included in the magnetic body 101 will be described in more detail. The first magnetic particles 111 may comprise an Fe-based alloy, such as an Fe-Si-Cr based alloy. The second magnetic particles 121 may comprise pure iron and may be in the form of, for example, carbonyl iron powder (CIP). As an example of a method for analyzing the composition and content of each component constituting the first magnetic particles 111 and the second magnetic particles 121, a cross-section of the magnetic body 101 may be analyzed by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). More specifically, the content of elements included in the first magnetic particles 111 and the second magnetic particles 121 can be obtained by analyzing an image obtained from a first-direction-third-direction (D1-D3) cross-section cut from the middle of the second direction D2 of the magnetic body 101, and may be an average value of the first magnetic particles 111 and the second magnetic particles 121 for different regions. Alternatively, an average value may be calculated after performing this analytical processing on multiple cross-sections of the magnetic body 101.

[0040] The first layer 112 of the first magnetic particle 111 may include Fe oxide, and it may be necessary to form a second layer 113. In this case, the first layer 112 of the first magnetic particle 111 may be a surface oxide film or a natural oxide film on the surface of the first magnetic particle 111. The thickness t1 of the first layer 112 of the first magnetic particle 111 may be defined as the distance from the outer surface of the first magnetic particle 111 to the outer surface of the first layer 112, and may correspond to the average thickness of the thickness measured in multiple regions. The average thickness t1 of the first layer 112 may be obtained by obtaining an SEM image or TEM image of at least one cross-section of the first magnetic particle 111 on which the first layer 112 is formed, and then measuring the thickness of multiple equally spaced regions. The first layer 112 of the first magnetic particle 111 may include at least one of Fe-O based materials and Fe-Si-O based materials, and for example, the first layer 112 may include Fe2O3. Unlike the second layer 113, even when the first layer 112 includes Fe-Si-O based materials, it is preferable to add a very small amount of Si. For example, the first layer 112 may include less than 1 wt% Si content relative to the total amount of the first layer 112. Furthermore, the first layer 112 may be formed in an amorphous structure; therefore, when analyzing the presence of the first layer 112, the first layer 112 can be analyzed by its composition rather than by its structure.

[0041] The first layer 112 of the first magnetic particles 111 may be structurally non-dense, thus allowing continuous permeation of moisture and oxygen. Furthermore, according to the inventors' research, the insulation of the magnetic body 101 may be significantly affected by the relatively large particle size of the first magnetic particles 111. Considering this, in some embodiments, a second layer 113 comprising Si oxide may be formed on the outer surface of the first layer 112, thereby improving the insulation of the magnetic body 101. The Si oxide of the second layer 113 may include SiO2. In this case, the Si component may be included in the second layer 113 in an amount of 30 wt% to 70 wt% relative to the total amount of the second layer 113. Since the second layer 113 may include Si oxide (e.g., SiO2), the insulation properties can be further improved, and the second layer 113 may have a uniform thickness. In the case of insulating coating materials based on Sn oxide and P oxide commonly used in the prior art, there are problems of low coating thickness uniformity and insufficient withstand voltage characteristics. Therefore, the second layer 113 of the first magnetic particles 111 may not include Sn and / or P components. According to some embodiments, the insulation properties of the magnetic particles 111 can be improved by a second layer 113 comprising Si oxide, and further, a saturation magnetization delay effect can be introduced. Additionally, as a bonus, the second layer 113 can have strong adhesion to the insulating material 110 included in the magnetic body 101, thereby improving high-temperature and high-humidity reliability. According to some embodiments, when the average particle size d1 of the first magnetic particles 111 is relatively large (e.g., 15 μm to 35 μm), the second layer 113 can exhibit further improvements in insulation properties (such as withstand voltage characteristics). Furthermore, the second layer 113 can be substantially free of Fe oxide.

[0042] According to some example embodiments of the method for forming the second layer 113 of the first magnetic particles 111, a liquid coating method can be used. For example, a liquid coating method utilizing tetraethyl orthosilicate (TEOS) can be used, and the second layer 113 can be uniformly coated at the tens of nm level by hydrolysis using ammonia as a catalyst. When the second layer 113 is uniformly formed, the insulation of the first magnetic particles 111 can be obtained. Here, the uniformity of the thickness of the second layer 113 can be defined as a value obtained by calculating the standard deviation of the thickness values ​​measured in multiple regions of the second layer 113 in the cross-section of the magnetic body 101, dividing the standard deviation by the average thickness t2, and then multiplying by 100%. In the case of this embodiment, the uniformity of the second layer 113 can be 90% or greater, or even 95% or greater.

[0043] In the multilayer insulating structure of the first magnetic particle 111, a second layer 113 may be provided to ensure more stable insulation properties, and the average thickness t2 may be from about 5 nm to 35 nm. If the average thickness t2 of the second layer 113 is insufficient, for example, less than about 5 nm, sufficient insulation may not be ensured. Furthermore, if the average thickness t2 of the second layer 113 is too thick, for example, exceeding about 35 nm, the second layer 113 may become excessively aggregated with another adjacent second layer 113. The thickness t2 of the second layer 113 may be defined as the distance from the outer surface of the first layer 112 to the outer surface of the second layer 113, and may correspond to the average thickness measured in multiple regions. The average thickness t2 of the second layer 113 may be obtained by obtaining an SEM or TEM image of at least one cross-section of the first magnetic particle 111 on which the first layer 112 and the second layer 113 are formed, and then measuring the thickness of multiple equally spaced regions. The average thickness t2 of the second layer 113 may be thicker than the average thickness t1 of the first layer 112, and may be 2 to 10 times the average thickness t1 of the first layer 112.

[0044] Furthermore, in the aforementioned example, a method for measuring the thicknesses t1 and t2 of the first layer 112 and the second layer 113 of the first magnetic particle 111 using SEM or TEM images has been described. However, thickness and elemental composition can also be analyzed using TEM-EDS analysis, and this analytical method can also be applied to the second magnetic particle 121. Specifically, after polishing the sample of the magnetic assembly 100, the cross-section of the first magnetic particle 111 with the first layer 112 and the second layer 113 formed in the magnetic body 101 can be observed using SEM. A focused ion beam (FIB) can be used to collect samples near the surface of the first magnetic particle 111, and a scanning transmission electron microscope (STEM) can be used to observe the first magnetic particle 111 and the insulating structure on its surface under magnification of 110K or greater and an accelerating voltage of 200kV. Thus, an EDS line profile scan can be performed from the vicinity of the surface of the first magnetic particle 111 to the insulating structure (first and second layers), and the first layer 112 can be defined as the region from the portion where the Fe content rapidly decreases to the portion where the Si content rapidly increases. Furthermore, the second layer 113 can be defined as the region from the part where the Si content increases rapidly to the part where the Si content decreases rapidly.

[0045] In the insulating structure of the second magnetic particle 121, as described above, the first layer 122 may include a P oxide, and unlike the first magnetic particle 111, the second magnetic particle 121 may have a single insulating structure. As described above, the first layer 122 of the second magnetic particle 121 may include a P oxide, and here, the first layer 122 of the second magnetic particle 121 may include a phosphate. In this disclosure, P oxide may refer to an oxide containing P, or a compound containing P and O. In the case of forming an insulating film (i.e., the first layer 122), the native oxide film present on the surface of the second magnetic particle 121 can be removed by treating the second magnetic particle 121 with a phosphate. Since the second magnetic particle 121, having a relatively small particle size, has a large specific surface area, the first layer 122 including a P oxide can be used as an insulating film, resulting in excellent wettability with the insulating material 110 of the magnetic body 101, thereby improving the structural stability of the magnetic body 101. The average thickness t3 of the first layer 122 of the second magnetic particle 121 may be from about 5 nm to 15 nm. The average thickness t3 of the first layer 122 can be defined as the distance from the outer surface of the second magnetic particle 121 to the outer surface of the first layer 122, and can correspond to the average thickness of the thickness measured in multiple regions. The average thickness t3 of the first layer 122 can be obtained by obtaining an SEM or TEM image of at least one cross-section of the second magnetic particle 121 on which the first layer 122 is formed, and then measuring the thickness of multiple equally spaced regions.

[0046] In the following text, reference will be made to Figures 5 to 7 Another embodiment of this disclosure is described. First, according to some embodiments, such as Figure 5 As shown, an additional coating can be formed on the surface of the first magnetic particle 111. Specifically, a third layer 114 can be formed on the outer surface of the second layer 113. Here, the third layer 114 can be a surface-treated layer obtained by surface-treating the second layer 113. By employing the third layer 114 in the form of a surface-treated layer, the magnetic particle 111 can have a hydrophobic surface and the bonding strength with the insulating material 110 of the magnetic body 101 can be increased, thereby improving the reliability of the magnetic assembly 100. Preferably, a material with excellent bonding strength with the second layer 113 and the insulating material 110 is used as the surface treatment agent for the second layer 113 of the magnetic particle 111. For example, the surface treatment agent may include at least one of oleic acid and a silane coupling agent, and a urethane silane coupling agent may be used as the silane coupling agent.

[0047] The third layer 114 may include compounds having at least one functional group selected from alkyl, carbonyl, and polyurethane acrylate. In this case, the functional groups included in the third layer 114 can be detected using Fourier transform infrared spectroscopy (FT-IR). When the third layer 114, as a surface treatment layer, is formed on the outer surface of the first magnetic particle 111, the magnetic body 101 may include at least one selected from oleic acid, oleic acid derivatives, carbonic acid, monoamide, N-allyl, and neopentyl esters. Here, oleic acid derivatives may include at least one selected from methyl oleate, butyl oleate, and 3-hydroxypropyl oleate. The above-mentioned components included in the magnetic body 101 can be detected by gas chromatography-mass spectrometry (GC-MS). As described above, the third layer 114 may have the function of improving the bonding strength with the insulating material 110 within the magnetic body 101. However, if the third layer 114 becomes too thick, the magnetic permeability of the magnetic body 101 may decrease; therefore, the average thickness t4 of the third layer 114 may be less than 10 nm.

[0048] According to another embodiment of this disclosure, such as Figure 6 and Figure 7 As shown, the magnetic body 101 may include relatively small-sized third magnetic particles 131, thus increasing the filling ratio of magnetic particles 111, 121, and 131 within the magnetic body 101. Specifically, the magnetic body 101 may also include a plurality of third magnetic particles 131 having an average particle size d3 smaller than the average particle size d2 of the plurality of second magnetic particles 121. The third magnetic particles 131 may fill the space between the first magnetic particles 111 and the second magnetic particles 121 to increase the total amount of magnetic particles 111, 121, and 131 present within the magnetic body 101. In this case, the average particle size d3 of the third magnetic particles 131 may be from about 5 nm to about 800 nm. The third magnetic particles 131 may include an Fe component and may be in the form of, for example, carbonyl iron powder (CIP). A first layer 132 may be formed as an insulating film on the surface of the third magnetic particles 131, and the first layer 132 of the third magnetic particles 131 may be an insulating film including a native oxide film, phosphate, etc. The average thickness t5 of the first layer 132 of the third magnetic particle 131 can be about 3 nm or less, more specifically, about 1 nm or less.

[0049] Reference Figures 8 to 10 Another embodiment of this disclosure is described. Unlike the previous embodiment where the coil 103 and the support member 102 supporting the coil were arranged within the magnetic body 101, in this case… Figures 8 to 10 In this embodiment, a wound coil is used. See [reference]. Figures 8 to 10The magnetic component 200 may include a molding portion 250, a coil 230, a cover portion 211, and receiving recesses h1 and h2. Furthermore, the magnetic component 200 may also include external electrodes 270 and 280. A magnetic body may form the appearance of the magnetic component 200, and the coil 230 may be embedded in the magnetic body. The magnetic body may include the molding portion 250 and the cover portion 211. The molding portion 250 may include a core 220. The magnetic body may be integrally formed in a hexahedral shape. The magnetic body may include a first surface 201 and a second surface 202 opposite to each other in a first direction D1, a third surface 203 and a fourth surface 204 opposite to each other in a second direction D2, and a fifth surface 205 and a sixth surface 206 opposite to each other in a third direction D3. Each of the third surface 203 to the sixth surface 206 of the magnetic body may correspond to a wall surface of the magnetic body connecting the first surface 201 and the second surface 202.

[0050] The magnetic components 200, on which the outer electrodes 270 and 280 (described below) are disposed, have a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.6 mm, but are not limited thereto. Additionally, the magnetic body may include a molding portion 250 and a cover portion 211, with the cover portion 211 disposed above the molding portion 250 and surrounding all surfaces except the lower surface of the molding portion 250. The molding portion 250 may have one surface and another surface opposite to each other. One surface of the molding portion 250 may correspond to the lower surface of the molding portion 250 and refers to the area where the receiving recesses h1 and h2, described below, are arranged. As described below, since the receiving recesses h1 and h2 are machined inside the molding portion 250, the bottom surface of the receiving recesses h1 and h2 may be disposed in the area between one surface and the other surface of the molding portion 250. The molding portion 250 may include a support portion 210 and a core 220. The support portion 210 may also have one surface and another surface opposite to each other, and one surface and another surface of the molding portion 250 correspond to one surface and another surface of the support portion 210. The core 220 may be disposed at the center of the other surface of the support portion 210 in the form of a through coil 230. The molding portion 250 may be formed by filling a mold with a composite material including first magnetic particles 111, second magnetic particles 121, and insulating resin. Here, the insulating resin may include, but is not limited to, epoxy resin, polyimide, liquid crystal polymer, etc., either alone or in combination.

[0051] The coil 230 can be embedded in a magnetic body and exhibit the characteristics of the magnetic component 200. For example, when the magnetic component 200 of this embodiment is used as a power inductor, the coil 230 can store an electric field as a magnetic field to maintain the output voltage, thereby stabilizing the power of the electronic device. The coil 230 is disposed on another surface of the molding portion 250. Specifically, the coil 230 is disposed on another surface of the support portion 210 in the form of winding around the core 220. The coil 230 can be an air-core coil and can be constructed as a flat coil. The coil 230 can be formed by winding a metal wire (such as copper wire) coated with an insulating material into a spiral shape. The coil 230 can include multiple layers. Each layer of the coil 230 can be formed as a flat spiral and can have multiple turns. That is, the coil 230 can include an innermost turn T1, at least one intermediate turn T2, and an outermost turn T3 arranged sequentially from the center to the outside of the other surface of the molding portion 250.

[0052] A cover portion 211 may be disposed on the molding portion 250 and the coil 230. The cover portion 211 covers the molding portion 250 and the coil 230. The cover portion 211 may be disposed on the support portion 210 and the core 220 of the molding portion 250 and the coil 230, and then pressed to be bonded to the molding portion 250. The molding portion 250 and the cover portion 211 may each include a first magnetic particle 111 and a second magnetic particle 121. In this case, as described above, a first layer 112 may be formed on the outer surface of at least one of the plurality of first magnetic particles 111 having a relatively large size, a second layer 113 may be formed on the outer surface of the first layer 112, and a first layer 122 may be formed on the outer surface of at least one of the plurality of second magnetic particles 121. Furthermore, the first layer 112 of the first magnetic particle 111 may include Fe oxide, and the second layer 113 of the first magnetic particle 111 may include Si oxide. Furthermore, the first layer 122 of the second magnetic particle 121 may include P oxide.

[0053] The first receiving recess h1 and the second receiving recess h2 may be formed spaced apart from each other on one surface of the molding portion 250, and the two ends of the coil 230, described below, are arranged in the first receiving recess h1 and the second receiving recess h2. For example, the first receiving recess h1 and the second receiving recess h2 may be formed on one surface of the molding portion 250 and spaced apart from each other in a third direction D3. The first receiving recess h1 and the second receiving recess h2 may be arranged outside the region corresponding to the core 220 on one surface of the molding portion 250, but are not limited thereto. The first receiving recess h1 and the second receiving recess h2 may be formed to extend in one direction on one surface of the molding portion 250, but may be formed in any shape without limitation, as long as it has a structure that effectively exposes the two ends of the coil 230.

[0054] Since the magnetic body comprises the area including the molding portion 250 and the cover portion 211, one surface of the magnetic body refers to the surface of the area including the molding portion 250 and the cover portion 211. The coil 230 is led out and includes a first lead-out portion disposed in the first receiving recess h1 and a second lead-out portion disposed in the second receiving recess h2. The first receiving recess h1 and the second receiving recess h2 are areas for pulling the two ends of the coil 230 out to the outer electrodes 270 and 280. Therefore, the first receiving recess h1 and the second receiving recess h2 are formed on one surface of the magnetic body and are spaced apart from each other to correspond to the first outer electrode 270 and the second outer electrode 280, respectively.

[0055] As an example, through recesses H1 and H2 can be formed by a mold during the forming of the molding portion 250, and a first receiving recess h1 and a second receiving recess h2 can be formed in the molding portion 250 during the process of forming the cover portion 211 by stacking and pressing magnetic sheets including magnetic metal particles. The mold used to form the molding portion 250 may include protrusions corresponding to the through recesses H1 and H2, such that the through recesses H1 and H2 can be formed in the molding portion 250 which is manufactured in a shape corresponding to the shape of the mold. Alternatively, the first receiving recess h1 and the second receiving recess h2 may not be formed during the process of forming the molding portion 250, but may be formed during the process of forming the cover portion 211 on the molding portion 250. That is, the two ends of the coil 230 protruding from one surface of the molding portion 250 through the through recesses H1 and H2 through the molding portion 250 can be embedded inside the molding portion 250 during the magnetic sheet pressing process. As a result, the first receiving recess h1 and the second receiving recess h2 can be formed on one surface of the molding portion 250. Optionally, the first receiving recess h1, the second receiving recess h2, and the through recesses H1 and H2 can be formed in a process of forming the molding portion 250 using a mold. In this case, the mold used to form the molding portion 250 may have protrusions formed to correspond to the first receiving recess h1, the second receiving recess h2, and the through recesses H1 and H2.

[0056] The two ends of the coil 230 can pass through a surface of the molding portion 250 to be respectively disposed in the first receiving recess h1 and the second receiving recess h2. The configuration of the ends of the coil 230 disposed in the receiving recesses h1 and h2 is not limited, so the widths of the first receiving recess h1 and the second receiving recess h2 can be the same as or different from the widths of the through recesses H1 and H2. The two ends of the coil 230 are exposed on a surface of the molding portion 250, namely, the second surface 202 of the magnetic body. The two ends of the coil 230 exposed on a surface of the molding portion 250 are disposed in the first receiving recess h1 and the second receiving recess h2, which are spaced apart from each other on the second surface 202 of the magnetic body. The two ends of the coil 230 can pass through the support portion 210 of the molding portion 250 and are exposed from a surface of the support portion 210. Although not specifically shown, since the two ends of the coil 230 have the same thickness as the coil 230, they can protrude from a surface of the support portion 210 by an amount corresponding to the thickness of the coil 230. Next, the two ends of the coil 230 can be pressed into the molding portion 250 in a process of forming the cover portion 211 by pressing a magnetic sheet including magnetic metal particles (simultaneously forming the first receiving recess h1 and the second receiving recess h2). However, the protruding ends can also be polished together in the process described below for polishing the openings for forming the resist plating of the outer electrodes 270 and 280, so that the ends of the coil 230 provided in the first receiving recess h1 and the second receiving recess h2 can be substantially smaller than the thickness of the coil 230.

[0057] The external electrodes 270 and 280 may be spaced apart from each other on one surface of the magnetic body (i.e., the second surface 202). Specifically, the external electrodes 270 and 280 may be spaced apart from each other on one surface of the molding portion 250 and may be respectively connected to the two ends of the coil 230 disposed in the first receiving recess h1 and the second receiving recess h2. Since the two ends of the coil 230 are arranged on the bottom surfaces of the first receiving recess h1 and the second receiving recess h2, and the external electrodes 270 and 280 are coated along the two ends of the coil 230, the external electrodes may be formed in a shape corresponding to the first receiving recess h1 and the second receiving recess h2. As an example, the external electrodes 270 and 280 may be formed by coating the two ends of the coil 230 disposed in the first receiving recess h1 and the second receiving recess h2 with a conductive resin including a conductive powder such as silver (Ag). The external electrodes 270 and 280 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 are not limited thereto. The external electrodes 270 and 280 may be formed in a single-layer or multi-layer structure.

[0058] Additionally, the magnetic component 200 according to this embodiment may also include an insulating layer 290 surrounding the surface of the coil 230. There are no limitations on the method of forming the insulating layer 290; however, for example, the insulating layer 290 may be formed by chemical vapor deposition of parylene resin or the like on the surface of the coil 230, or by known methods such as screen printing, exposure and development of photoresist (PR), spraying, or dipping. The insulating layer 290 is not particularly limited, as long as it can be formed as a thin film, but it may be formed to include, for example, photoresist (PR), epoxy resin, etc.

[0059] In the case of the magnetic component according to the example of this disclosure, the eddy current loss characteristics, structural stability, etc. of the magnetic body including magnetic particles can be improved.

[0060] 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 magnetic assembly comprising: magnetic body, wherein the magnetic body includes a plurality of first magnetic particles including a Fe component and a plurality of second magnetic particles including a Fe component, and an average particle diameter of the plurality of second magnetic particles is smaller than an average particle diameter of the plurality of first magnetic particles, an outer surface of at least one of the plurality of first magnetic particles is formed with a first layer, and an outer surface of the first layer is formed with a second layer, an outer surface of at least one of the plurality of second magnetic particles is formed with a first layer, the first layer of the at least one of the first magnetic particles includes a Fe oxide, and the second layer of the at least one of the first magnetic particles includes a Si oxide, and the first layer of the at least one of the second magnetic particles includes a P oxide.

2. The magnetic assembly of claim 1, wherein, The average particle diameter of the plurality of first magnetic particles is 15 μm to 35 μm.

3. The magnetic assembly of claim 1, wherein, The average thickness of the second layer of the at least one of the first magnetic particles is 5 nm to 35 nm.

4. The magnetic assembly of claim 1, wherein, The first layer of the at least one of the first magnetic particles includes less than 1 wt% of a Si component with respect to a total amount of the first layer of the at least one of the first magnetic particles.

5. The magnetic assembly of claim 1, wherein, The second layer of the at least one of the first magnetic particles includes 30 wt% to 70 wt% of a Si component with respect to a total amount of the second layer of the at least one of the first magnetic particles.

6. The magnetic assembly of claim 1, wherein, The second layer of the at least one of the first magnetic particles does not include a Sn component and / or a P component.

7. The magnetic assembly of claim 1, wherein, The average particle diameter of the plurality of second magnetic particles is 0.9 μm to 4.5 μm.

8. The magnetic assembly of claim 1, wherein, The average thickness of the first layer of the at least one of the second magnetic particles is 5 nm to 15 nm.

9. The magnetic assembly of claim 1, wherein, The first layer of the at least one of the second magnetic particles includes a phosphate.

10. The magnetic assembly of claim 1, wherein, An outer surface of the second layer of the at least one of the first magnetic particles is formed with a third layer.

11. The magnetic assembly of claim 10, wherein, The third layer includes a compound having at least one functional group selected from the group consisting of an alkyl group, a carbonyl group, and a polyurethane acrylate.

12. The magnetic assembly of claim 11, wherein, The average thickness of the third layer is less than 10 nm.

13. The magnetic assembly of claim 1, wherein, The plurality of first magnetic particles includes a Fe-Si-Cr-based alloy.

14. The magnetic assembly of claim 1, wherein, The magnetic body further includes a plurality of third magnetic particles including a Fe component, and an average particle diameter of the plurality of third magnetic particles is smaller than an average particle diameter of the plurality of second magnetic particles.

15. The magnetic assembly of claim 14, wherein, The average particle diameter of the plurality of third magnetic particles is 5 nm to 800 nm.

16. A magnetic assembly comprising: magnetic body, wherein the magnetic body includes a plurality of first magnetic particles including a Fe component and a plurality of second magnetic particles including a Fe component, and an average particle diameter of the plurality of second magnetic particles is smaller than an average particle diameter of the plurality of first magnetic particles, an outer surface of at least one of the plurality of first magnetic particles is formed with a first layer, and an outer surface of the first layer is formed with a second layer, an outer surface of at least one of the plurality of second magnetic particles is formed with a first layer, The first layer of the at least one first magnetic particle comprises Fe oxide, and the second layer of the at least one first magnetic particle is free of Fe oxide, The first layer of the at least one second magnetic particle is not formed with a second layer on an outer surface thereof.

17. The magnetic assembly of claim 16, wherein, The second layer of the at least one first magnetic particle comprises Si oxide.

18. The magnetic assembly of claim 16, wherein, The first layer of the at least one second magnetic particle comprises P oxide.

19. The magnetic assembly of claim 16, wherein, The average particle size of the plurality of first magnetic particles is 15 μm to 35 μm.

20. The magnetic assembly of claim 16, wherein, The average thickness of the second layer of the at least one first magnetic particle is 5 nm to 35 nm.

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