Electronic components

Abstract

The present invention provides an electronic component, which includes: a magnetic body, which includes a resin and a first magnetic powder, and has a groove on the lower surface of the magnetic body; an internal coil portion, which is embedded in the magnetic body; and an external electrode, which is arranged on the opposite ends of the magnetic body in the length direction of the magnetic body and connected to the end of the internal coil portion, wherein the first magnetic powder arranged on the surface of the groove may have a cutting surface.

Description

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2018-0016406 filed on February 9, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] The present disclosure relates to an electronic assembly. Background Art

[0003] An inductor (an electronic component) is a typical passive element that forms an electronic circuit together with a resistor and a capacitor to eliminate noise.

[0004] The film type inductor is manufactured by forming an inner coil part by plating, curing a magnetic powder / resin composite obtained by mixing magnetic powder with resin to produce a magnetic body, and forming external electrodes on the outer surface of the magnetic body. Summary of the invention

[0005] Exemplary embodiments of the present disclosure may provide a space in which a molding material (eg, epoxy molding compound) may sufficiently penetrate between a board and an inductor during packaging.

[0006] Exemplary embodiments of the present disclosure may also provide an excellent inductor having increased inductance.

[0007] According to an exemplary embodiment of the present disclosure, an electronic component may include: a magnetic body, including a resin and a first magnetic powder, and having a groove on a lower surface of the magnetic body; an internal coil portion, embedded in the magnetic body; and an external electrode, arranged on opposite ends of the magnetic body in a length direction of the magnetic body and connected to the end of the internal coil portion, wherein the first magnetic powder arranged on a surface of the groove has a cutting surface.

[0008] According to another exemplary embodiment of the present disclosure, an electronic component may include: a magnetic body, including a resin and a magnetic powder and having a first region and a second region, the second region being arranged on both sides of the first region in the length direction of the magnetic body, and having a thickness greater than that of the first region in the thickness direction of the magnetic body; an inner coil portion embedded in the magnetic body; and an outer electrode, arranged on opposite ends of the magnetic body in the length direction of the magnetic body and connected to the ends of the inner coil portion, wherein the magnetic powder arranged on the surface of the first region may have a cut surface, and in the first region, the surface of the resin and the cut surface of the magnetic powder are coplanar. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, features and advantages of the present disclosure will be more clearly understood through the following detailed description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a perspective view showing an electronic component according to an exemplary embodiment of the present disclosure;

[0011] Figure 2 is along Figure 1 A cross-sectional view taken along line II' in FIG.

[0012] Figure 3 is along Figure 1 A cross-sectional view taken along line II-II';

[0013] Figure 4 It is shown Figure 2 An enlarged schematic diagram of an exemplary embodiment of part A;

[0014] Figure 5 is a flow chart illustrating a process of manufacturing an electronic component according to an exemplary embodiment of the present disclosure;

[0015] FIG. 6A to FIG. 6D are diagrams sequentially illustrating a process of manufacturing an electronic component according to an exemplary embodiment of the present disclosure;

[0016] Figure 7 is a perspective view showing an electronic component of the prior art; and

[0017] Figure 8 is along Figure 7 A cross-sectional view taken along line II'. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present disclosure will now be described in detail hereinafter with reference to the accompanying drawings.

[0019] In the drawings, direction W, direction T, and direction L may represent a width direction, a thickness direction, and a length direction of the chip-type electronic component, respectively.

[0020] Electronic components

[0021] Hereinafter, an electronic component according to an exemplary embodiment of the present disclosure will be described, but the present disclosure is not limited thereto.

[0022] Figure 1 is a perspective view illustrating an electronic component according to an exemplary embodiment of the present disclosure. Figure 2 is along Figure 1 A cross-sectional view taken along line II' in FIG. Figure 3 is along Figure 1 A cross-sectional view taken along line II-II'.

[0023] Reference Figures 1 to 3 , a thin-film inductor used for a power line of a power circuit is shown as an example of the electronic component 100.

[0024] The electronic component 100 according to an exemplary embodiment of the present disclosure includes: a magnetic body 150; a first internal coil portion 142 and a second internal coil portion 144, which are embedded in the magnetic body 150; an insulating layer 160, which is arranged on the upper surface of the magnetic body 150 and on the groove R on the lower surface of the magnetic body 150; and an external electrode 180, which is arranged outside the magnetic body 150 and is electrically connected to the first internal coil portion 142 and the second internal coil portion 144.

[0025] The magnetic body 150 includes a first magnetic powder. The first magnetic powder is not limited as long as it exhibits magnetic properties, and can be formed using, for example, ferrite. The ferrite can be, for example, Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Zn-Cu-based ferrite, Mn-Mg-based ferrite, Ba-based ferrite, Li-based ferrite, etc. The first magnetic powder can be an alloy including at least one selected from the group consisting of Fe, Si, Cr, Al, B and Cu, and can include, for example, Fe-Si-B-Cr-based amorphous metal particles, but is not limited thereto.

[0026] The first magnetic powder may be dispersed in a thermosetting resin such as an epoxy resin, an acrylic resin, or a polyimide resin.

[0027] The magnetic body 150 includes first magnetic powder and thermosetting resin.

[0028] The magnetic body 150 has a groove R on its lower surface. In the width direction (W direction) of the magnetic body, the width of the groove R is equal to the width of the magnetic body 150. In the length direction (L direction) of the magnetic body, the length of the groove R is less than the length of the magnetic body 150.

[0029] The magnetic body 150 may be divided into a first region ( Figure 2 The “region I” in FIG. 1 ) and the second regions ( Figure 2 In the thickness direction (T direction) of the magnetic body, the thickness of the second region is greater than the thickness T2a of the first region. The thickness difference between the second region and the first region is equal to the depth T2b of the groove R from the lower surface of the magnetic body 150.

[0030] The insulating layer 160 may be disposed on the upper surface of the magnetic body 150 and on the groove R on the lower surface of the magnetic body 150 to prevent or reduce the occurrence of a plating diffusion phenomenon when an external electrode is formed by subsequent plating. The insulating layer 160 may cover the entire upper surface of the magnetic body 150. The insulating layer 160 may not be formed on the lower surface except for the groove R. The insulating layer 160 may include a second magnetic powder. The second magnetic powder may be formed using the same material as the first magnetic powder. Due to the inclusion of the second magnetic powder, the insulating layer 160 not only prevents or reduces the plating diffusion phenomenon, but also contributes to the formation of the inductance. In the thickness direction (T direction) of the magnetic body, the thickness T3 of the insulating layer 160 may be less than the depth T2b of the groove R.

[0031] The external electrode 180 is formed on the opposite end surfaces of the magnetic body 150 in the length direction. The external electrode 180 may be formed using a conductive material (e.g., a conductive metal) having excellent conductivity. For example, the external electrode 180 may be formed using nickel (Ni), copper (Cu), tin (Sn), or a combination thereof. The external electrode 180 has an L shape and covers the lower surface of the second region of the magnetic body 150. The external electrode 180 is not formed on the upper surface of the magnetic body 150. Therefore, the thickness T2a of the first region of the magnetic body 150 is greater than that of the electronic component (inductor) representing the prior art. Figure 8 The thickness T2 of the magnetic body 50 is greater than the thickness T1 of the external electrode 80. The thickness T1' of the external electrode 180 is less than Figure 8 The thickness T1 of the external electrode 80 in the groove R may be less than the depth T2b of the groove R. Because the thickness of the external electrode 180 formed by plating is uniform in all directions due to the plating characteristics, and the thickness T1' of the external electrode 180 is less than Figure 8 The thickness T1 of the outer electrode 80 in the embodiment is such that the length L2' of the magnetic body 150 may be greater than Figure 8 The length L2 of the magnetic body 50. Figure 2 In the embodiment, the thickness L1' of the external electrode 180 in the length direction is equal to the thickness T1' in the thickness direction. Figure 8 The thickness L1 of the external electrode 80 in the length direction may be equal to the thickness T1 in the thickness direction.

[0032] Prior art electronic components (inductors) such as Figure 7 and Figure 8As shown. The electronic component (inductor) of the prior art includes: a magnetic body 50; a first internal coil portion 42 and a second internal coil portion 44, which are embedded inside the magnetic body 50; an insulating layer 60, which is arranged on the upper surface and the lower surface of the magnetic body 50; an external electrode 80, which is arranged outside the magnetic body 50 and is electrically connected to the first internal coil portion 42 and the second internal coil portion 44. The first internal coil portion 42 and the second internal coil portion 44 may be respectively arranged on two opposite surfaces of the base layer 20, and the first internal coil portion 42 and the second internal coil portion 44 may be covered with an insulating layer 48. In addition, a core portion 55 is formed in the magnetic body 50.

[0033] The external electrode 80 is formed on the end surfaces of the magnetic body 50 opposite in the length direction, and is formed on the upper and lower surfaces of the magnetic body 50. The external electrode 80 covers a portion of the insulating layer 60 formed on the upper and lower surfaces of the magnetic body 50. The external electrode 80 may include an external electrode layer 81 formed using a conductive paste and a plating layer 82 formed on the external electrode layer 81 by plating. The external electrode layer 81 may be a conductive resin layer including at least one conductive metal selected from the group consisting of copper (Cu), nickel (Ni) and silver (Ag) and a thermosetting resin. The plating layer 82 may include at least one selected from the group consisting of nickel (Ni), copper (Cu) and tin (Sn). For example, a Cu layer, a Ni layer and a Sn layer may be formed sequentially.

[0034] As electronic devices become increasingly high-performance and multifunctional and miniaturized, the number of components increases, and therefore, methods have been sought to package ICs and passive components into a single module to reduce the mounting area. In addition, because the electronic components (inductors) used in such miniaturized electronic devices also need to be smaller and thinner, the electronic components (inductors) have limited sizes (such as limited chip thickness Tc and limited chip length Lc). In order to allow the molding material (e.g., epoxy molding compound) to fully penetrate between the circuit board and the electronic component (inductor) during packaging, a predetermined gap is required between the electronic component (inductor) and the circuit board. To this end, in the prior art, by forming a thick outer electrode 80 having a thickness T1, the vertical distance G from the surface of the insulating layer 60 to the lower surface of the outer electrode 80 is formed to have a desired value (e.g., at least 5 μm). In order to form the outer electrode 80 to be thick while meeting the limited size of the electronic component (inductor), the thickness T2 of the magnetic body 50 is inevitably reduced. That is, in the case where the external electrode 80 is formed to be thick, the volume of the magnetic body 50 is inevitably reduced. This leads to deterioration of the inductor characteristics.

[0035] According to Figures 1 to 3The present exemplary embodiment shown can increase the volume of the magnetic body while maintaining the same dimensions (chip thickness Tc and chip length Lc, etc.) as those of the electronic component (inductor) of the related art, and the vertical distance G from the surface of the insulating layer 160 to the lower surface of the external electrode 180 can have a desired value (e.g., a minimum value of 5 μm or more). Therefore, an excellent electronic component (inductor) with increased inductance can be obtained while satisfying the physical conditions required for the electronic component (inductor) when the IC and passive components are packaged in a single module.

[0036] The first inner coil part 142 having a coil shape pattern is formed on one surface of the base layer 120 disposed inside the magnetic body 150 , and the second inner coil part 144 having a coil shape pattern is formed on the other surface of the base layer 120 opposite to the one surface.

[0037] The base layer 120 is formed using, for example, a polypropylene glycol (PPG) substrate, a ferrite substrate, a metal-based soft magnetic substrate, or the like.

[0038] A central portion of the base layer 120 is penetrated to form a hole, and the hole is filled with the first magnetic powder to form the core portion 155. Inductance may be improved by forming the core portion 155 filled with the first magnetic powder.

[0039] The first and second internal coil parts 142 and 144 may have a spiral shape and may be formed on opposite surfaces of the base layer 120. The first and second internal coil parts 142 and 144 are electrically connected to each other via a via electrode 146 penetrating the base layer 120.

[0040] The first and second internal coil portions 142 and 144 and the via electrode 146 may be formed using a metal having excellent electrical conductivity, for example, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt) or alloys thereof.

[0041] The first inner coil portion 142 and the second inner coil portion 144 may be covered with an insulating layer 148. The insulating layer 148 may be formed by a known method such as a screen printing method, by a process of exposing and developing a photoresist (PR), a spraying process, etc. The first inner coil portion 142 and the second inner coil portion 144 may be covered with the insulating layer 148 and may not be in direct contact with the magnetic material included in the magnetic body 150.

[0042] One end of the first internal coil portion 142 formed on one side of the base layer 120 may be exposed to one end surface of the magnetic body 150 in the length direction, and one end of the second internal coil portion 144 formed on the other side of the base layer 120 opposite to the one side may be exposed to the other end surface of the magnetic body 150 in the length direction.

[0043] The outer electrodes 180 are formed on opposite end surfaces of the magnetic body 150 in the length direction and are connected to the first and second inner coil parts 142 and 144 exposed at the opposite end surfaces of the magnetic body 150 in the length direction.

[0044] Figure 4 yes Figure 2 A schematic enlarged view of an exemplary embodiment of part A.

[0045] Reference Figure 4 , the magnetic body 150 includes a first magnetic powder 151 and a resin 152. The first magnetic powder 151 located on the surface of the groove R may have a flat cut surface. In the groove R, the surface of the resin 152 and the cut surface of the first magnetic powder 151 may be coplanar. The particle size distribution D50 of the first magnetic powder 151 may be 0.1 μm to 25 μm, which is measured using a laser diffraction scattering method using a particle diameter and particle size distribution measuring device. The particle diameter of the first magnetic powder 151 may be 0.1 μm to 50 μm.

[0046] Method of manufacturing an electronic assembly

[0047] Figure 5 is a flow chart illustrating a process of manufacturing an electronic component according to an exemplary embodiment of the present disclosure. FIG. 6A to FIG. 6D 1 is a diagram sequentially showing a process of manufacturing an electronic component according to an exemplary embodiment of the present disclosure. The process is used to manufacture a plurality of electronic components, but FIG. 6A to FIG. 6D A single electronic component is shown.

[0048] Reference Figure 5 and Fig. 6A In operation S10 , the first and second internal coil parts 142 and 144 are formed on one surface and opposite surfaces of the base layer 120 .

[0049] The method of forming the first inner coil portion 142 and the second inner coil portion 144 may be, for example, an electroplating method, but is not limited thereto. The first inner coil portion 142 and the second inner coil portion 144 may be formed using a metal having excellent electrical conductivity, and for example, a material such as silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt), or an alloy thereof may be used.

[0050] An insulating layer 148 may be formed on surfaces of the first and second internal coil parts 142 and 144. The insulating layer 148 may be formed by a known method such as a screen printing method, a process of exposing and developing photoresist (PR), a spraying process, or the like.

[0051] Reference Figure 5 and Figure 6B In operation S20 , a plurality of magnetic sheets 150 a , 150 b , 150 c , 150 d , 150 e , 150 f , and 150 g are stacked above and below the first and second internal coil parts 142 and 144 to form a magnetic body 150 .

[0052] For example, a plurality of magnetic sheets 150a, 150b, 150c, 150d, 150e, 150f and 150g may be prepared by mixing a first magnetic powder with an organic material such as a binder, a solvent, etc. to prepare a slurry; applying the slurry to a carrier film by a doctor blade method to have a thickness of tens of micrometers and drying it.

[0053] After stacking the plurality of magnetic sheets 150a, 150b, 150c, 150d, 150e, 150f, and 150g, the plurality of stacked magnetic sheets 150a, 150b, 150c, 150d, 150e, 150f, and 150g may be pressed by a lamination method or a hydrostatic pressing method and cured to form the magnetic body 150. The magnetic body 150 may include a resin and a first magnetic powder dispersed in the resin.

[0054] Reference Figure 5 and Figure 6C , in operation S30 , a groove R is formed on the lower surface of the magnetic body 150 .

[0055] The groove R may be formed in the central portion of the lower surface of the magnetic body 150 by removing a portion of the magnetic body 150 through a cutting process. Since the magnetic powder and the resin of the magnetic body 150 are removed together by a blade, the magnetic powder located on the surface of the groove R has a flat cut surface. In the groove R, the cut surface of the magnetic powder and the surface of the resin may be coplanar.

[0056] Reference Figure 5 and Fig.6D In operation S40 , an insulating layer 160 is formed on the entire upper surface of the magnetic body 150 and on the groove R.

[0057] When the external electrodes are formed by plating, the insulating layer 160 can prevent or reduce the plating diffusion phenomenon. The insulating layer 160 can be formed using, for example, epoxy resin. That is, the insulating layer 160 can be formed using an insulating paste including epoxy resin. The insulating layer 160 can include the second magnetic powder, and the insulating layer 160 can have an epoxy resin content of 30 vol% to 60 vol%.

[0058] Return to reference Figure 2In operation S50 , the external electrode 180 is formed to be connected to ends of the first and second internal coil parts 142 and 144 exposed to both end surfaces of the magnetic body 150 in the length direction.

[0059] The external electrode 180 may be formed by plating, including electroplating, electroless plating, and the like.

[0060] For example, the external electrode 180 may be formed by sequentially forming a copper (Cu) layer, a nickel (Ni) layer, and a tin (Sn) layer.

[0061] As set forth above, according to the exemplary embodiments of the present disclosure, since the volume of the magnetic body is increased, an excellent inductor having increased inductance may be provided.

[0062] According to an exemplary embodiment of the present disclosure, a space in which a molding material (eg, epoxy molding compound) can sufficiently penetrate between a board and an inductor during packaging may be provided.

[0063] While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. An electronic component, comprising: a magnetic body including a resin and first magnetic particles and having a groove on a lower surface of the magnetic body; An inner coil portion, embedded in the magnetic body; as well as an outer electrode disposed on a lower surface of the magnetic body and on opposite ends of the magnetic body in a length direction of the magnetic body and connected to an end of the inner coil portion, wherein a portion of the outer electrode extends to the groove, and Wherein, the length of the external electrode disposed on the lower surface of the magnetic body in the thickness direction of the magnetic body is smaller than the depth of the groove.

2. The electronic component according to claim 1, wherein: The first magnetic particles disposed on the surface of the groove have a cut surface, and In the groove, a surface of the resin and the cut surface of the first magnetic particle are coplanar.

3. The electronic component according to claim 1, wherein: The width of the groove is equal to the width of the magnetic body.

4. The electronic assembly according to claim 1, further comprising: An insulating layer is disposed on the upper surface of the magnetic body and on the groove.

5. The electronic component according to claim 4, wherein: The insulating layer includes second magnetic particles.

6. The electronic component according to claim 4, wherein: The thickness of the insulating layer is smaller than the depth of the groove.

7. The electronic component according to claim 1, wherein: The outer electrode covers the lower surface outside the groove.

8. The electronic component according to claim 1, wherein: The external electrode is formed using nickel, copper, tin or an alloy thereof.

9. An electronic component, comprising: a magnetic body including a resin and magnetic particles and having a first region and a second region, the second region being disposed on both sides of the first region in a length direction of the magnetic body and having a thickness greater than that of the first region in a thickness direction of the magnetic body; An inner coil portion, embedded in the magnetic body; as well as an outer electrode provided at opposite ends of the magnetic body in the length direction of the magnetic body and connected to an end of the inner coil portion, The external electrode is not disposed on the upper surface of the magnetic body, and a portion of the external electrode extends to the first region along the lower surface of the magnetic body.

10. The electronic component according to claim 9, wherein: The magnetic body has a groove on a lower surface thereof.

11. The electronic component according to claim 10, wherein: A difference in thickness between the second region and the first region is equal to a depth of the groove from the lower surface of the magnetic body.

12. The electronic component according to claim 10, wherein: The outer electrode covers the lower surface outside the groove.

13. The electronic assembly according to claim 10, further comprising: An insulating layer is disposed on the upper surface of the magnetic body and on the groove.

14. The electronic component according to claim 9, wherein: The magnetic particles disposed on the surface of the first region have cut surfaces, and in the first region, the surface of the resin and the cut surfaces of the magnetic particles are coplanar.

15. The electronic component according to claim 9, wherein: The inner coil part overlaps at least a portion of the second region and the first region when viewed in a thickness direction of the magnetic body.

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