Coil electronics assembly

Abstract

A coil electronic component includes a main body including a coil portion disposed in the main body and including a plurality of magnetic particles, and an external electrode connected to the coil portion. The main body includes an inner region and a protective layer disposed on a surface of the inner region. First particles among the plurality of magnetic particles included in the protective layer include an oxide film disposed on a surface of the first particles, and second particles among the plurality of magnetic particles included in the main body include a coating layer disposed on a surface of the second particles, the second particles having a size greater than a size of the first particles, the coating layer having a different composition from a composition of the oxide film.

Description

[0001] This application is a divisional application of the patent application with application number 201911266269.3, filed on December 11, 2019, and with the title of "Coil Electronic Assembly". TECHNICAL FIELD

[0002] The present disclosure relates to a coil electronic assembly. BACKGROUND

[0003] As electronic devices such as digital TVs, mobile phones, laptop computers, etc. have been designed to have reduced sizes, coil electronic assemblies applied to such electronic devices need to have reduced sizes. To meet such a demand, a great deal of research has been conducted to develop various types of coil-type or thin film-type coil electronic assemblies.

[0004] An important consideration in developing a coil electronic assembly having a reduced size is to achieve the same properties as before after reducing the size of the coil electronic assembly. To this end, it can be necessary to increase the content of a magnetic material filling the core. However, there can be limitations in increasing the content of the magnetic material due to the strength of the inductor body, changes in frequency properties caused by insulating properties, and other reasons.

[0005] As an example of manufacturing a coil electronic assembly, a body can be implemented by laminating a sheet formed of a mixture of magnetic particles, resin, etc. on a coil and pressing the sheet. Ferrite, metal, etc. can be used as the magnetic particles. When metal is used as the magnetic particles, the content of the particles can be preferably increased in terms of the permeability characteristics of the coil electronic assembly, but in this case, the insulating properties of the body can be deteriorated, so that the breakdown voltage properties can be deteriorated. SUMMARY

[0006] An aspect of the present disclosure is to provide a coil electronic assembly having improved breakdown voltage properties by improving the insulating properties of a body. Since the insulating properties of the body are improved, the coil electronic assembly can have improved magnetic properties while reducing the size of the body.

[0007] According to an aspect of the present disclosure, a coil electronic assembly can include a body including a coil portion disposed in the body and including a plurality of magnetic particles, and an external electrode connected to the coil portion. The body includes an inner region and a protective layer disposed on a surface of the inner region. First particles of the plurality of magnetic particles included in the protective layer can include an oxide film disposed on a surface of the first particles, and second particles of the plurality of magnetic particles included in the body include a coating layer disposed on a surface of the second particles, the second particles having a size greater than a size of the first particles. The coating layer can have a different composition from a composition of the oxide film.

[0008] The coating layer provided on the surface of the second particle can be configured as an inorganic coating layer including a P component.

[0009] The coating layer can include a P-based glass.

[0010] The thickness of the coating layer can be 10 nm to 60 nm.

[0011] The coating layer provided on the surface of the second particle can be configured as an atomic layer deposition layer.

[0012] The first particle can include pure iron.

[0013] The first particle can have a diameter of 5 µm or less.

[0014] The second particle can include an Fe-based alloy.

[0015] The second particle can have a diameter of 10 µm to 25 µm.

[0016] The thickness of the protective layer can be 4 µm to 40 µm.

[0017] The oxide film can include an oxide including a metal component included in the first particle.

[0018] The thickness of the oxide film can be 200 nm or less.

[0019] Part of the plurality of magnetic particles included in the inner region can include an oxide film provided on a surface of the part of the particles.

[0020] The oxide film in the inner region can have a thickness smaller than a thickness of the oxide film in the protective layer.

[0021] An amount of the oxide film included in the protective layer per unit volume can be higher than an amount of the oxide film included in the inner region per unit volume.

[0022] The thickness of the oxide film of the protective layer can decrease from an outer surface of the protective layer to the inner region.

[0023] When the protective layer includes two regions having the same thickness as each other, a thickness of the oxide film in a region adjacent to a surface of the main body can be greater than a thickness of the oxide film in a region adjacent to the inner region.

[0024] According to another aspect of the present disclosure, a coil electronic assembly can include a main body including a coil portion disposed in the main body and including a plurality of magnetic particles, and an external electrode connected to the coil portion, wherein a first particle of the plurality of magnetic particles included in the main body includes an oxide film disposed on a surface of the first particle, and a thickness of the oxide film on the surface of the first particle adjacent to a surface of the main body is greater than a thickness of the oxide film on the surface of the first particle adjacent to an inner region of the main body.

[0025] The first particle having the oxide film on a surface thereof can have a diameter of 5 µm or less.

[0026] The oxide film can have a thickness of 200 nm or less. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1 is a perspective view illustrating a coil electronic assembly according to an exemplary embodiment of the present disclosure;

[0029] Figure 2 and Figure 3 are respectively enlarged views illustrating one region of a main body of a coil electronic assembly, and respectively illustrate one region of a protective layer and one region of an inner region. Figure 1 are respectively cross-sectional views taken along lines I-I' and II-II' in Figure 1

[0030] Figure 4 and Figure 5 are respectively enlarged views illustrating one region of a main body of a coil electronic assembly, and respectively illustrate one region of a protective layer and one region of an inner region. DETAILED DESCRIPTION

[0031] Hereinafter, exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0032] However, the present disclosure can be embodied in many different forms and should not be construed as being limited to the specific exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Accordingly, the shapes and dimensions of elements in the drawings can be exaggerated for the sake of clarity. In addition, elements having the same function in the drawings represented in each of the exemplary embodiments will be described using the same reference numerals.

[0033] Figure 1 ​is a perspective view showing a coil electronic assembly according to an exemplary embodiment of the present disclosure. Figure 2 and Figure 3 are respectively cross-sectional views taken along lines I-I' and II-II' of the coil electronic assembly shown in Figure 1 Figure 1 are respectively cross-sectional views taken along lines I-I' and II-II' of the coil electronic assembly shown in Figure 4 and Figure 5 are respectively enlarged views showing one region of a main body of the coil electronic assembly, and respectively show one region of a protective layer and one region of an inner region.

[0034] Referring to the drawings, a coil electronic assembly 100 in an exemplary embodiment of the present disclosure can include a main body 101, a support substrate 102, a coil portion 103, and outer electrodes 105 and 106, and the main body 101 can include a plurality of magnetic particles 112 and 212. Also, the coil portion 103 can include an upper coil portion 103a and a lower coil portion 103b. The main body 101 can include an inner region 120 and a protective layer 110 disposed on a surface of the inner region 120. Part of the particles 112 (hereinafter, referred to as first particles) can include an oxide film 113 disposed on a surface of the first particles. Part of the particles 212 (hereinafter, referred to as second particles) having a size greater than that of the first particles 112 can include a coating layer 213 having a different composition from that of the oxide film 113 and disposed on a surface of the second particles 212. According to an exemplary embodiment of the present disclosure, the second particles 212 can be included as a necessary element, but in other exemplary embodiments, the second particles 212 can not be provided.

[0035] The main body 101 can seal at least a portion of the support substrate 102 and the coil portion 103, and can form an outer appearance of the coil electronic assembly 100. The main body 101 can be configured to outwardly expose a partial region of a lead pattern L. As shown in Figure 4 and Figure 5 The main body 101 can include a plurality of magnetic particles 112 and 212, and the magnetic particles 112 and 212 can be dispersed in an insulating material 111, as shown in

[0036] According to an exemplary embodiment of the present disclosure, the main body 101 can include the magnetic particles 112 and 212 having different sizes, thereby increasing an amount of the magnetic particles 112 and 212 included in the main body 101. For the first particles 112 having a relatively small size, the first particles 112 can fill spaces between the second particles 212. The first particles 112 can include pure iron, and can have a form of, for example, carbonyl iron powder (CIP). A diameter d1 of the first particles 112 can be 5 µm or less.

[0037] ​An oxide film 113 can be disposed on the surface of the first particles 112. For example, as shown in Figure 4 and Figure 5 The oxide film 113 can be disposed on the surface of the first particles 112 included in the protective layer 110 in the main body 101, and the oxide film 113 can also be disposed on the surface of the first particles 112 included in the inner region 120. Alternatively, the oxide film 113 can not be disposed on the surface of the first particles 112 included in the inner region 120. Figure 5 An example in which a coating layer is not disposed on the first particles 112 in which the oxide film 113 is not included is illustrated, but exemplary embodiments are not limited thereto. A coating layer for protecting the first particles 112 can be formed. For example, the coating layer can be configured as an inorganic coating layer or an atomic layer deposition layer including a phosphorus (P) component. When the coating layer is disposed on the surface of the first particles 112, the oxide film 113 obtained by oxidizing the first particles 112 and the coating layer can form a multi-layer structure, and the coating layer 213 and the oxide film 113 can be formed in a mixed manner.

[0038] The oxide film 113 on the surface of the first particles 112 can be an oxide of a metal component included in the first particles 112. For example, when the first particles 112 include pure iron, the oxide film 113 can be iron oxide (Fe2O3). The thicknesses t1 and t3 of the oxide film 113 can be 200 nm or less. According to exemplary embodiments of the disclosure, the oxide film 113 can be effectively disposed on the first particles 112 of the protective layer 110 forming the outer layer of the main body 101 by adjusting process conditions for forming the oxide film 113. Accordingly, the insulating properties of the protective layer 110 can be improved. When the insulating properties of the protective layer 110 are improved, the inductive properties and the breakdown voltage (BDV) properties of the coil electronic assembly 100 can also be improved.

[0039] Referring to Figure 4 and Figure 5The thickness t3 of the oxide film 113 in the inner region 120 can be smaller than the thickness t1 of the oxide film 113 of the protective layer 110. In the main body 101, the amount of the oxide film 113 included in the protective layer 110 per unit volume can be higher than the amount of the oxide film 113 included in the inner region 120 per unit volume, which can be expressed by a volume fraction. The oxide film 113 on the surface of the first particles 112 can be formed by performing heat treatment on the main body 101, and by exposing the main body 101 to ozone or the like. Since the first particles 112 can be oxidized more actively on the surface of the main body 101, a larger amount of the oxide film 113 can be provided in the protective layer 110 (outer layer of the main body 101), and the protective layer 110 can improve the insulating properties of the main body 101. This is because, when the insulating properties in the outer layer of the main body 101 adjacent to the outer electrodes 105 and 106 are susceptible to influence, the breakdown voltage can be significantly reduced. Further, when the main body 101 is polished to prevent chipping defects or other defects, the first particles 112 can be exposed from the surface of the main body 101, or the thickness of the insulating film on the surface of the magnetic particles 112 becomes uneven. In this case, the insulating properties of the main body 101 can further deteriorate. According to the exemplary embodiment of the present disclosure, by forming the protective layer 110 including the oxide film 113 on the surface of the main body 101, the above-described problems can be reduced.

[0040] The size of the protective layer 110 can be adjusted by changing the heat treatment temperature or the ozone concentration for forming the oxide film 113. According to the research conducted by the inventors, when the thickness T of the protective layer 110 is 4 μm to 40 μm, improvement in the inductance properties and the breakdown voltage properties is ensured. When the heat treatment temperature is excessively increased or the heat treatment time is excessively long, the thickness of the oxide film 113 increases. Thus, although the insulating properties are improved, the inductance performance deteriorates. In this case, as described above, the thickness t1 and t3 of the oxide film 113 provided in the protective layer 110 and the inner region 120 can be 200 nm or less.

[0041] For the protective layer 110 obtained by the above-described method, the size of the oxide film 113 on the surface of the first particles 112 can vary in different regions. For example, the thickness of the oxide film 113 can decrease from the outer surface of the protective layer 110 to the inner region 120. Further, when the protective layer 110 is divided into two regions having the same thickness, the thickness of the oxide film 113 in the region provided adjacent to the surface of the main body 101 can be greater than the thickness of the oxide film 113 in the region provided adjacent to the inner region 120. This is because, as described above, the oxide film 113 can have a greater thickness on the surface of the main body 101.

[0042] The second particles 212 having a relatively large size can include an Fe-based alloy or the like. For example, the second particles 212 can include a nanocrystalline alloy having a composition of Fe-Si-B-Cr, Fe-Ni-based alloy, or the like. The diameter d2 of the second particles 212 can be 10 μm to 25 μm. When a portion of the magnetic particles includes an Fe-based alloy as described above, the magnetic properties such as magnetic permeability can be improved, but the magnetic particles can be susceptible to electrostatic discharge (ESD). Accordingly, a coating layer 213 can be disposed on the surface of the second particles 212. The coating layer 213 can have a composition different from that of the oxide film 113 of the first particles 112.

[0043] According to research by the inventors, during a process of oxidizing the body 101, the oxide film 113 is selectively formed only on the surface of the first particles 112, and no oxide film is disposed on the second particles 212, or a small amount of oxide film is formed. When a small amount of oxide film is disposed on the second particles 212, the thickness of the oxide film on the second particles 212 can be less than the thickness of the oxide film 113 on the first particles 112. The oxide film on the second particles 212 can denote an oxide film disposed on the surface of the second particles 212 or the surface of the coating layer 213. When the body 101 is oxidized by a heat treatment process, the oxide film 113 starts to be disposed on the first particles 112 having a relatively small size in a temperature range of 100 °C to 200 °C (a relatively low temperature), whereas the second particles 212 start to be oxidized at a temperature of 500 °C or more (a temperature significantly higher than the above-described temperature). At the temperature at which the second particles 212 are oxidized, damage can be caused to the insulating material 111 or the like. Accordingly, the body 101 can be oxidized at a temperature lower than the above-described temperature, thereby selectively oxidizing the first particles 112.

[0044] The coating layer 213 on the surface of the second particles 212 can be configured as an inorganic coating layer including a P component. For example, the coating layer 213 can include a P-based glass. The P-based inorganic coating layer can include elements such as P, Zn, Si, or the like, and can include oxides of the elements. When the coating layer 213 is configured as a P-based inorganic coating layer, the thickness t2 of the coating layer 213 can be 10 nm to 60 nm.

[0045] The coating layer 213 on the surface of the second particles 212 can also be configured as an atomic layer deposition (ALD) layer. Atomic layer deposition can be a process of uniformly coating a surface of an object in atomic layers during a process in which a reaction material is periodically supplied and discharged through surface chemical reactions. The coating layer 213 obtained through the above process can have a reduced and uniform thickness and improved insulation performance. Thus, even when the main body 101 is filled with a large number of second particles 212, the insulation performance of the main body 101 can be effectively ensured. When the coating layer 213 is configured as an atomic layer deposition layer, the thickness of the coating layer 213 can be reduced, so that the size of the main body 101 can be reduced, and the thickness of the coating layer 213 can be 10 nm to 15 nm. Further, when the coating layer 213 is configured as an atomic layer deposition layer, the coating layer 213 can include aluminum oxide (Al2O3), silicon dioxide (SiO2), or the like. The coating layer 213 can also include various materials formed through atomic layer deposition in addition to the above-described materials. For example, the coating layer 213 can include materials such as TiO2, ZnO2, HfO2, Ta2O5, Nb2O5, Sc2O3, Y2O3, MgO, B2O3, GeO2, or the like. According to an exemplary embodiment of the present disclosure, the coating layer 213 can have a multi-layer structure including a P-based inorganic coating layer and an atomic layer deposition layer.

[0046] As an example of a method of manufacturing the main body 101, the main body 101 can be formed through a lamination process. For example, the coil portion 103 can be disposed on the support substrate 102 using a plating process or the like, a plurality of unit laminates for manufacturing the main body 101 can be prepared, and the unit laminates can be stacked. The unit laminates can be manufactured by making a slurry using a mixture of the magnetic particles 112 and 212 (including metal) and an organic material such as a thermosetting resin, an adhesive, a solvent, or the like, coating a carrier film with the slurry using a doctor blade method at a thickness of several tens of μm, drying the slurry, and manufacturing the unit laminates in a sheet form. Thus, the manufactured unit laminates can include magnetic particles dispersed in a thermosetting resin such as an epoxy resin, polyimide, or the like. A plurality of unit laminates can be formed, and the unit laminates can be stacked in the upper and lower portions of the coil portion 103 and can be pressed, thereby implementing the main body 101. The oxide film 113 can be disposed on the magnetic particles 112 present in the main body 101 through the oxidation process as described above, in which case, a relatively thin oxide film 113 can be disposed on the magnetic particles 112 of the inner region 120, or the oxide film 113 can not be disposed on the magnetic particles 112 of the inner region 120.

[0047] Reference will now be made to Figures 1 to 3Other elements are described. The support substrate 102 can support the coil part 103, and can be implemented as a polypropylene glycol (PPG) substrate, a ferrite substrate, or a metal-based soft magnetic substrate, etc. As shown, a through-hole penetrating the support substrate 102 can be formed in a central portion of the support substrate 102, and the through-hole can be filled with the main body 101, thereby forming a magnetic core part C. According to an exemplary embodiment of the disclosure, the support substrate 102 can not be provided.

[0048] The coil part 103 can be provided in the main body 101, and can perform various functions in an electronic device by a property realized by a coil of the coil electronic component 100. For example, the coil electronic component 100 can be implemented as a power inductor, in which case the coil part 103 can stabilize power by storing power in the form of a magnetic field and maintaining an output voltage. A coil pattern included in the coil part 103 can be laminated on both surfaces of the support substrate 102, and can be electrically connected through a conductive via V penetrating the support substrate 102. The coil part 103 can be formed in a spiral form, and a lead-out pattern L can be included in an outermost region of the spiral form, for electrical connection with the external electrodes 105 and 106.

[0049] The coil part 103 can be provided on at least one of a first surface (an upper surface in Figure 2 ) and a second surface (a lower surface in Figure 2 ) of the support substrate 102 that face each other. According to an exemplary embodiment of the disclosure, the coil part 103 can be provided on both the first surface and the second surface of the support substrate 102, in which case the coil part 103 can include a pad area P. Alternatively, the coil part 103 can be provided on only one of the surfaces of the support substrate 102. A coil pattern included in the coil part 103 can be formed using a plating process used in the related art, such as a pattern plating process, an anisotropic plating process, an isotropic plating process, etc., and can be constructed to have a multi-layer structure using a plurality of the above processes.

[0050] The external electrodes 105 and 106 can be provided outside the main body 101, and can be connected to the lead-out pattern L. The external electrodes 105 and 106 can be formed using a paste including a metal having high electrical conductivity, for example, which can be an electrically conductive paste including one or alloys thereof of nickel (Ni), copper (Cu), tin (Sn), and silver (Ag). Each of the external electrodes 105 and 106 can further include a plating layer (not shown) provided thereon. In this case, the plating layer can include one or more elements selected from the group consisting of nickel (Ni), copper (Cu), and tin (Sn). For example, a nickel (Ni) plating layer and a tin (Sn) plating layer can be formed in order.

[0051] According to the foregoing exemplary embodiment, in a coil electronic component, a breakdown voltage property can be improved as an insulating property of a main body is improved.​​

[0052] While the foregoing exemplary embodiments have been shown and described, it will be apparent to those of ordinary skill in the art that modifications and variations can be made without departing from the scope of the disclosure as defined by the appended claims.

Claims

1. A coil electronic component comprising: a main body including a plurality of magnetic particles; a coil portion provided in the main body, and an external electrode connected to the coil portion, wherein the main body includes an inner region and a protective region provided on a surface of the inner region, wherein the plurality of magnetic particles include first particles and second particles, the second particles having a size larger than a size of the first particles, the first particles included in the plurality of magnetic particles and included in the protective region include an oxide formed on a surface of the first particles, and the second particles included in the plurality of magnetic particles and included in the protective region include a coating layer provided on a surface of the second particles, the coating layer having a composition different from a composition of the oxide, wherein the oxide includes an oxide including a metal component included in the first particles, and wherein the coating layer on the surface of the second particles includes an inorganic coating layer and / or an atomic layer deposition layer including a P component.

2. The coil electronic assembly of claim 1, wherein, The oxide on the surface of the first particles contacts the first particles, and the coating layer on the surface of the second particles contacts the second particles.

3. The coil electronic assembly of claim 1, wherein, The coating layer includes a P-based glass.

4. The coil electronic assembly of claim 1, wherein, The coating layer has a thickness of 10 nm to 60 nm.

5. The coil electronic assembly of claim 1, wherein, The first particles include pure iron.

6. The coil electronic assembly of claim 1, wherein, The first particles have a diameter of 5 μm or less.

7. The coil electronic assembly of claim 1, wherein, The second particles include an Fe-based alloy.

8. The coil electronic assembly of claim 1, wherein, The second particles have a diameter of 10 μm to 25 μm.

9. The coil electronic assembly of claim 1, wherein, The protective region has a thickness of 4 μm to 40 μm.

10. The coil electronic assembly of claim 1, wherein, The oxide on the surface of the first particles includes an oxide of iron.

11. The coil electronic assembly of claim 1, wherein, The oxide has a thickness of 200 nm or less.

12. The coil electronic assembly of claim 1, wherein, A portion of the first particles included in the plurality of magnetic particles and included in the inner region includes an oxide formed on a surface of the portion of the first particles, and another portion of the first particles included in the plurality of magnetic particles and included in the inner region has no oxide formed on a surface of the another portion of the first particles.

13. The coil electronic assembly of claim 12, wherein, The oxide on the first particles in the inner region has a thickness smaller than a thickness of the oxide on the first particles in the protective region.

14. The coil electronic assembly of claim 12, wherein, An amount of the oxide included in the protective region per unit volume is higher than an amount of the oxide included in the inner region per unit volume.

15. The coil electronic assembly of claim 1, wherein, The thickness of the oxide in the protective region decreases from an outer surface of the protective region to the inner region.

16. The coil electronic assembly of claim 1, wherein, When the protective region includes two regions having the same thickness as each other, a thickness of the oxide in a region adjacent to a surface of the main body is greater than a thickness of the oxide in a region adjacent to the inner region.

17. The coil electronic assembly of claim 1, wherein, A portion of the first particles included in the plurality of magnetic particles and included in the inner region includes an oxide formed on a surface of the first particles, and the second particles included in the plurality of magnetic particles and included in the inner region include a coating layer provided on a surface of the second particles.

18. The coil electronic assembly of claim 1, wherein, Part of the second particles includes an oxide formed on a surface of the second particle or a surface of the coating layer, and a thickness of the oxide on the second particle is smaller than a thickness of the oxide on the first particle.

19. A coil electronic component comprising: a main body including a plurality of magnetic particles; a coil portion provided in the main body; and an external electrode connected to the coil portion, wherein the main body includes an inner region and a protective region provided on a surface of the inner region, first particles included in the protective region among the plurality of magnetic particles include an oxide formed on a surface of the first particle, and the inner region includes the first particles on which the oxide is formed on a surface of the particle, and a thickness of the oxide on a surface of the first particle adjacent to a surface of the main body in the protective region is greater than a thickness of the oxide on a surface of the first particle in the inner region of the main body. The first particle having the oxide on a surface thereof has a diameter of 5 μm or less.

20. The coil electronic assembly of claim 19, wherein, The thickness of the oxide is 200 nm or less.

21. The coil electronic assembly of claim 19, wherein, ​

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