阅读说明：本技术 功率电感器及其制造方法 (Power inductor and manufacturing method thereof ) 是由 金炅泰 徐泰根 于 2018-12-07 设计创作，主要内容包括：本发明公开一种功率电感器及其制造方法。所述功率电感器包括本体；线圈图案,设置于所述本体中；外部电极,设置于所述本体的至少一个表面上且延伸至所述本体的与所述至少一个表面相邻的至少另一表面；以及耦合层,设置于所述本体与所述外部电极的延伸区域之间。(The invention discloses a power inductor and a manufacturing method thereof. The power inductor comprises a body; a coil pattern disposed in the body; an external electrode disposed on at least one surface of the body and extending to at least another surface of the body adjacent to the at least one surface; and a coupling layer disposed between the body and the extension region of the external electrode.)

1. A power inductor, comprising:

a body;

a coil pattern disposed in the body;

an external electrode disposed on at least one surface of the body and extending to at least another surface of the body adjacent to the at least one surface; and

and the coupling layer is arranged between the body and the extension region of the external electrode.

2. The power inductor defined in claim 1, wherein the body has beveled edges.

3. The power inductor defined in claim 1, further comprising a surface insulating layer disposed on at least one region of a surface of the body.

4. The power inductor according to claim 3, wherein the surface insulating layer is disposed on a surface other than a surface connecting the coil pattern to the external electrode.

5. The power inductor recited in claim 3 wherein said coupling layer is disposed between said surface insulating layer and said extended region of said external electrode.

6. The power inductor of claim 1, wherein the coupling layer comprises a metal or metal alloy.

7. The power inductor according to claim 6, wherein at least a portion of the outer electrode comprises a same material as at least one of the coil pattern and the coupling layer.

8. The power inductor according to claim 6, wherein the external electrode comprises a first layer configured to contact the coil pattern and the coupling layer and at least one second layer disposed on the first layer and made of a different material than the first layer.

9. A method of manufacturing a power inductor, the method comprising:

preparing a body in which a coil pattern is formed;

forming a surface insulating layer on a surface of the body;

forming a coupling layer on a predetermined region on the surface insulating layer;

removing a portion of the coupling layer and a portion of the surface insulating layer to expose the coil pattern; and

forming an external electrode on at least one surface of the body such that the external electrode is connected to the coil pattern.

10. The method of manufacturing a power inductor according to claim 9, further comprising: forming an edge of the body to be inclined before the forming of the surface insulating layer.

11. The method of manufacturing a power inductor according to claim 9, wherein the external electrode extends from at least one surface of the body to at least one surface of the body adjacent to the at least one surface.

12. The method of manufacturing a power inductor according to claim 11, wherein the coupling layer is formed on an extended region of the external electrode.

13. The method of manufacturing a power inductor according to claim 12, wherein at least a portion of the outer electrode is formed using the same material and the same method as at least one of the coil pattern and the coupling layer.

Technical Field

The present disclosure relates to a power inductor and a method of manufacturing the same, and more particularly, to a power inductor capable of improving a coupling force between a body and an external electrode and a method of manufacturing the same.

Background

As a chip component, the power inductor is generally disposed on a power circuit (e.g., a Direct Current (DC) -DC converter) in the portable device. Due to the trend of power supply circuits toward high frequency and miniaturization, power inductors are increasingly used instead of conventional wound-type choke coils (w out-type choke coils). In addition, with the demand for small-sized multifunctional portable devices, power inductors are being developed to achieve miniaturization, high current, and low resistance.

A typical power inductor is manufactured in the form of a laminated body in which ceramic sheets formed of a plurality of ferrites or dielectric materials having a low dielectric constant are laminated. Here, when the coil patterns are formed on each of the ceramic sheets, the coil patterns formed on the ceramic sheets may be connected through via holes defined in each of the ceramic sheets, and may have a structure in which the coil patterns overlap each other in a vertical direction in which the sheets are stacked. In general, a body formed by laminating ceramic sheets is manufactured using a magnetic material (a quaternary system including nickel (Ni) -zinc (Zn) -copper (Cu) -iron (Fe)).

However, since the magnetic material has a saturation magnetization value smaller than that of the metal material, high current characteristics required for recent portable devices may not be realized. Therefore, when the body of the power inductor is made of metal powder, the saturation magnetization value may increase relative to the case where the body is made of a magnetic material. However, when the body is made of metal, material loss may increase due to an increase in eddy current loss and high frequency hysteresis.

To reduce the loss of material, a structure is applied in which a polymer is used to insulate the metal powder. That is, the body of the power inductor is manufactured by laminating sheets in which metal powder and polymer are mixed. In addition, a predetermined base material in which the coil pattern is formed is provided in the body, and an external electrode connected to the coil pattern is provided outside the body. That is, the power inductor is manufactured in the following manner: a body is manufactured by forming a coil pattern on a predetermined base material and laminating and pressing a plurality of sheets above and below the coil pattern, and then an external electrode is formed outside the body.

The external electrodes of the power inductor may be formed by applying a conductive paste (conductive paste). That is, the external electrodes are formed by applying a metal paste on both sides of the body to be connected to the coil patterns. In addition, the external electrode may be formed by further forming a plating layer on the metal paste. However, the external electrode formed using the metal paste may be separated from the body due to weak coupling force. That is, a power inductor mounted to an electronic device may be applied with tension (tensile force), and since the power inductor in which an external electrode is formed using a metal paste has weak tensile strength (tensile strength), a body and the external electrode may be separated from each other.

[ Prior art documents ]

Korean laid-open patent No. 2007-0032259

Disclosure of Invention

Technical problem

The present disclosure provides a power inductor capable of improving a coupling force between a body and an external electrode to improve a tensile strength, and a method of manufacturing the same.

The present disclosure also provides a power inductor capable of improving a coupling force between a body and an extended region of an external electrode, and a method of manufacturing the same.

Means for solving the problems

According to an exemplary embodiment, a power inductor includes: a body; a coil pattern disposed in the body; an external electrode disposed on at least one surface of the body and extending to at least another surface of the body adjacent to the at least one surface; and a coupling layer disposed between the body and the extension region of the external electrode.

The body may have a beveled edge.

The power inductor may further include a surface insulation layer disposed on at least one region of the surface of the body.

The surface insulating layer may be disposed on the remaining surface except the surface connecting the coil pattern to the external electrode.

The coupling layer may be disposed between the surface insulating layer and the extension region of the external electrode.

The coupling layer may comprise a metal or metal alloy.

At least a portion of the outer electrode may include a same material as at least one of the coil pattern and the coupling layer.

The external electrode may include a first layer configured to contact the coil pattern and the coupling layer, and at least one second layer disposed on the first layer and made of a different material from the first layer.

According to another exemplary embodiment, a method of manufacturing a power inductor includes: preparing a body in which a coil pattern is formed; forming a surface insulating layer on a surface of the body; forming a coupling layer on a predetermined region on the surface insulating layer; removing a portion of the coupling layer and a portion of the surface insulating layer to expose the coil pattern; and forming an external electrode on at least one surface of the body such that the external electrode is connected to the coil pattern.

The method may further comprise forming the edge of the body to be inclined before the forming the surface insulating layer.

The external electrode may extend from at least one surface of the body to at least one surface of the body adjacent to the at least one surface.

The coupling layer may be formed on an extended region of the external electrode.

At least a portion of the external electrode may be formed using the same material and the same method as at least one of the coil pattern and the coupling layer.

ADVANTAGEOUS EFFECTS OF INVENTION

In the power inductor according to the exemplary embodiment, the external electrode connected to the coil pattern may be made of the same metal as the coil pattern, and may be formed using the same method as the coil pattern. That is, at least a partial thickness of the external electrode connected to the coil pattern on the side surface of the body may be formed using the same method as the coil pattern (e.g., plating). Therefore, the coupling force between the body and the external electrode can be improved, and thus the tensile strength can also be improved.

In addition, exemplary embodiments may further include a coupling layer disposed between the external electrode and the top and bottom surfaces and the front and rear surfaces (i.e., the curved portions) of the body to which the external electrode extends. Since the coupling layer is provided, the coupling force of the external electrode can be improved, and thus the tensile strength can also be improved.

In addition, when parylene (parylene) is applied on the coil pattern, parylene may be formed on the coil pattern in a uniform thickness, and thus, an insulating property between the body and the coil pattern may be improved.

In addition, since at least two base materials are provided in the body and each of the at least two base materials is formed with a coil pattern having a coil shape on at least one surface, the plurality of coils may be formed in one body and thus the capacity of the power inductor may be increased.

The exemplary embodiments can be applied to various chip components for forming external electrodes, in addition to the power inductor.

Drawings

Fig. 1 is a perspective view of a power inductor according to an exemplary embodiment.

Fig. 2 and 3 are sectional views taken along a line a-a' shown in fig. 1 according to exemplary embodiments and modified examples of the exemplary embodiments.

Fig. 4 and 5 are exploded perspective and partial plan views according to an exemplary embodiment.

Fig. 6 to 7 are cross-sectional views of coil patterns in a power inductor according to an exemplary embodiment.

Fig. 8 and 9 show cross sections of the power inductor depending on the material of the insulating layer.

Fig. 10 is a perspective view of a power inductor according to a modified example of an exemplary embodiment.

Fig. 11 to 17 are sectional views for sequentially explaining a method of manufacturing a power inductor according to an exemplary embodiment.

Fig. 18 is a graph illustrating tensile strength of a power inductor according to a related art example and an exemplary embodiment.

Fig. 19 is a cross-section illustrating a power inductor according to an exemplary embodiment after a tensile strength experiment.

Fig. 20 to 23 are perspective and cross-sectional views for explaining a winding type inductor in a process sequence according to another exemplary embodiment.

Fig. 24 to 26 are cross-sectional views of power inductors according to other exemplary embodiments.

Detailed Description

Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. This disclosure may, however, be embodied in different forms and should not be construed as limited to the 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 disclosure to those skilled in the art.

Fig. 1 is a coupling perspective view illustrating a power inductor according to an exemplary embodiment, and fig. 2 and 3 are sectional views taken along a line a-a' of fig. 1 according to the exemplary embodiment and modified examples. Fig. 4 is an exploded perspective view illustrating a power inductor according to an exemplary embodiment, fig. 5 is a plan view illustrating a base material and a coil pattern, and fig. 6 and 7 are cross-sectional views illustrating the base material and the coil pattern to explain a shape of the coil pattern. Fig. 8 and 9 are cross-sectional views showing the power inductor according to the material of the insulating layer. In addition, fig. 10 is a perspective view illustrating a power inductor according to a modified example of the exemplary embodiment. The exemplary embodiments can be applied to a chip assembly forming an external electrode, and a power inductor will be explained as an exemplary embodiment.

Referring to fig. 1 and 10, a power inductor according to an exemplary embodiment may include: a body (100a, 100 b; 100); at least one base material (200) disposed in the body (100); a coil pattern (310, 320; 300) disposed on at least one surface of the base material (200); and an external electrode (410, 420; 400) disposed outside the body (100). In addition, the power inductor may further include an inner insulating layer (510) and a surface insulating layer (520), the inner insulating layer (510) is disposed between the coil patterns (310, 320) and the body (100), and the surface insulating layer (520) is disposed on a surface of the body on which the external electrode is not disposed. In addition, the power inductor may further include a coupling layer (600), the coupling layer (600) being disposed on the remaining surface of the body (100) between the body (100) and the external electrode (400) except for two surfaces exposing the coil pattern (300). As shown in fig. 10, the power inductor may further include a top cap insulating layer (530), the top cap insulating layer (530) being disposed on the top surface of the body (100).

1. Body

The body (100) may have a hexahedral shape. However, the body (100) may have a polyhedral shape other than a hexahedral shape. In addition, the body (100) may have chamfered edges. That is, the edges where two or three surfaces are adjacent to each other may be formed in an inclined manner. The edge may be formed to have a predetermined inclination without having a right angle, or may be formed in a circular manner. Here, the inclined or rounded edges may have at least one portion with a different inclination. The body (100) may contain metal powder (110) and insulating material (120) as shown in fig. 2 and may further contain a thermally conductive filler (130) as shown in fig. 3.

The metal powder (110) may haveAn average particle diameter (mean particle diameter) of approximately 1 micron to approximately 100 microns. In addition, the metal powder (110) may use a single type or at least two types of particles having the same size or a single type or at least two types of particles having a plurality of sizes. For example, a first metal powder having an average particle size of approximately 20 to approximately 100 microns, a second metal powder having an average particle size of approximately 2 to approximately 20 microns, and a third metal powder having an average particle size of approximately 1 to approximately 10 microns may be mixed for use. That is, the metal powder (110) may include: a first metal powder, wherein the median value of the average particle size or particle size distribution (D50) is between approximately 20 microns and approximately 100 microns; a second metal powder, wherein the median value of the average particle size or particle size distribution (D50) is between approximately 2 microns and approximately 20 microns; and a third metal powder, wherein the median value of the average particle size or particle size distribution (D50) is between approximately 1 micron and approximately 10 microns. Here, the first metal powder may be larger than the second metal powder, and the second metal powder may be larger than the third metal powder. Here, the metal powder may be the same kind of powder or different kinds of powder. In addition, the mixing ratio (mixing ratio) of the first metal powder, the second metal powder and the third metal powder may be, for example, 5 to 9:0.5 to 2.5, preferably 7:1: 2. That is, for approximately 100 wt% of the metal powder (110), approximately 50 wt% to approximately 90 wt% of the first metal powder, approximately 5 wt% to approximately 25 wt% of the second metal powder, and approximately 5 wt% to approximately 25 wt% of the third metal powder may be mixed. Here, the first metal powder may be contained more than the second metal powder, and the second metal powder may be contained equal to or less than the third metal powder. Preferably, for approximately 100 wt% of the metal powder (110), approximately 70 wt% of the first metal powder, approximately 10 wt% of the second metal powder, and approximately 20 wt% of the third metal powder may be mixed. Since the metal powder (110) in which metal powders having at least two, and preferably three or more, average particle diameters are uniformly mixed together is distributed throughout the body (100), the magnetic permeability (magnetic permeability) can be uniform throughout the body (100). When the sizes of the use are different from each otherThe same at least two metal powders (110), the filling rate of the body (100) can be increased to maximize the capacity. For example, in the case of using metal powder having an average size of approximately 30 μm, pores (pores) may be generated between the metal powder, and thus the filling rate may be lowered. However, when metal powder having a size of approximately 3 micrometers is mixed between metal powder having a size of approximately 30 micrometers, the filling rate of the metal powder in the body (100) may be increased. The metal powder (110) may use a metal material including iron (Fe). For example, the metal powder (110) may comprise at least one metal selected from the group consisting of: iron nickel (Fe-Ni), iron nickel silicon (Fe-Ni-Si), iron aluminum silicon (Fe-Al-Si), and iron aluminum chromium (Fe-Al-Cr). That is, the metal powder (110) may include iron to have a magnetic composition or may be formed of a metal alloy having magnetism to have a predetermined magnetic permeability. In addition, the surface of the metal powder (110) may be coated with a magnetic material having a magnetic permeability different from that of the metal powder (110). For example, the magnetic material may comprise a metal oxide magnetic material. The metal oxide magnetic material may include at least one selected from the group consisting of: nickel oxide magnetic materials, zinc oxide magnetic materials, copper oxide magnetic materials, magnesium oxide magnetic materials, cobalt oxide magnetic materials, barium oxide magnetic materials, and nickel-zinc-copper oxide magnetic materials. That is, the magnetic material coated on the surface of the metal powder (110) may be formed of a metal oxide containing iron and preferably has a magnetic permeability greater than that of the metal powder (110). Since the metal powders (110) have magnetism, when the metal powders (110) contact each other, insulation between the metal powders (110) may be broken and a short circuit may occur. Thus, the surface of the metal powder (110) may be coated with at least one insulating material. For example, the surface of the metal powder (110) may be coated with an oxide or an insulating polymeric material (e.g., parylene). Here, parylene is preferable. Parylene may be coated at a thickness of approximately 1 micron to approximately 10 microns. Here, when parylene is coated at a thickness of less than approximately 1 micron, the insulating effect of the metal powder (110) may be deteriorated, and when largeWhen parylene is coated at a thickness of approximately 10 microns, the magnetic permeability may decrease as the size of the metal powder (110) increases and the distribution of the metal powder (110) in the body (100) decreases. In addition, the surface of the metal powder (110) may be coated with various insulating polymer materials in addition to parylene. The oxide applied to the metal powder (110) may be formed by oxidizing the metal powder (110). Alternatively, the metal powder (110) may be coated with at least one selected from the group consisting of: TiO 2₂、SiO₂、ZrO₂、SnO₂、NiO、ZnO、CuO、CoO、MnO、MgO、Al₂O₃、Cr₂O₃、Fe₂O₃、B₂O₃And Bi₂O₃. Here, the metal powder (110) may be coated with an oxide having a double structure (e.g., a double structure formed of an oxide and a polymer material). Alternatively, the surface of the metal powder (110) may be coated with a magnetic material and then coated with an insulating material. Since the surface of the metal powder (110) is coated with an insulating material, short-circuiting due to contact between the metal powder (110) can be prevented. Here, the metal powder (110) is coated with an oxide or an insulating polymer material or a double structure of a magnetic material and an insulating material having a thickness of approximately 1 micrometer to approximately 10 micrometers.

The insulation material (120) may include an insulation material (120) to insulate the metal powders (110) from each other, that is, the metal powders (110) may increase eddy current loss and high frequency hysteresis, thereby causing loss of the material, in order to reduce loss of the material, the insulation material (120) may include at least one selected from the group consisting of epoxy resin (epoxy), polyimide, and liquid crystal polymer (L CP), however, exemplary embodiments are not limited thereto, and in addition, the insulation material (120) may be made of a thermosetting BPA resin (thermoplastic resin) to provide insulation properties between the metal powders (110), for example, the thermosetting resin may include at least one selected from the group consisting of novolac epoxy resin (novolac epoxy resin), phenoxy epoxy resin (phenoxy-type epoxy resin), bisphenol a-type epoxy resin (bisphenol a-epoxy resin), and epoxy resin (epoxy resin) to reduce the amount of epoxy resin (epoxy resin) when the epoxy resin (epoxy resin is used in a resin, the epoxy resin (epoxy resin) may be used in a process, so that the amount of the epoxy resin (epoxy resin) may be reduced to a value of approximately 0% when the metal powder (epoxy resin is used, the metal powder (epoxy resin, the epoxy resin may be reduced, and the amount of epoxy resin may be within a reduced, which may be within a range of approximately 100% of the metal powder.

However, there are limitations as follows: the inductance of a power inductor manufactured using the metal powder (110) and the insulating material (120) decreases as the temperature increases. That is, the following limitations are generated: the temperature of the power inductor is increased due to heat generated from an electronic device to which the power inductor is applied, and thus, the inductance is reduced while the metal powder (110) forming the body of the power inductor is heated. To address the above-mentioned limitation in which the body (100) is heated by external heat, the body (100) may include a thermally conductive filler (130). That is, when the metal powder (110) of the body (100) is heated by external heat, the heat of the metal powder (110) may be discharged to the outside due to the inclusion of the heat conductive filler (130). Although the thermally conductive filler (130) may include at least one selected from the group consisting of: MgO, AlN, carbon-based material, nickel-based material, and manganese-based material, but the exemplary embodiments are not limited thereto. Here, the carbon-based materialThe material may include carbon and have various shapes. For example, the carbon-based material may include graphite, carbon black, graphene, and the like. In addition, the nickel-based ferrite may include NiO, ZnO and CuO-Fe₂O₃And the manganese-based ferrite may include MnO, ZnO and CuO-Fe₂O₃. Since the heat conductive filler is made of a ferrite material, it is preferable to prevent the magnetic permeability from increasing or decreasing. The thermally conductive filler (130) may be distributed in a powder form and contained in the insulating material (120). In addition, the thermally conductive filler (130) may be included in a content of approximately 0.5 wt% to approximately 3 wt%, based on approximately 100 wt% of the metal powder (110). When the content of the heat conductive filler (130) is less than the above range, a heat discharging effect may be achieved, and when the content of the heat conductive filler (130) is greater than the above range, as the content of the metal powder (110) decreases, the magnetic permeability of the body (100) decreases. Additionally, the thermally conductive filler (130) may have a size of, for example, approximately 0.5 microns to approximately 100 microns. That is, the heat conductive filler (130) may have the same size as the metal powder (110) or a smaller size than the metal powder (110). The heat discharge effect of the heat conductive filler (130) can be adjusted according to the size and content of the heat conductive filler (130). For example, as the size and content of the heat conductive filler increases, the heat discharging effect may be enhanced. The body (100) may be manufactured by laminating a plurality of sheets made of materials including metal powder (110), an insulating material (120), and a thermally conductive filler (130). Here, when the plurality of sheets are laminated to manufacture the body (100), the content of the thermally conductive filler (130) may be different for each of the sheets. For example, as the thermally conductive filler (130) gradually moves upward and downward away from the center of the base material (200), the content of the thermally conductive filler (130) within the sheet may gradually increase. That is, the content of the thermally conductive filler (130) may be different in the vertical direction (i.e., Z direction). In addition, the content of the thermally conductive filler (130) may be different in a horizontal direction (i.e., at least one of the X direction and the Y direction). That is, the content of the thermally conductive filler (130) may be different within the same sheet. In addition, the body (100) can be manufactured by applying various methods such as the following, as necessary: a method of printing a paste made of metal powder (110), an insulating material (120), and a heat conductive filler (130) in a predetermined thickness, orMethod of pressing the paste into the frame. Here, the number of stacked sheets used to form the body (100) or the thickness of paste printed at a predetermined thickness may be appropriately determined in consideration of electrical characteristics such as inductance required for a power inductor. In an exemplary embodiment, the body (100) further includes a thermally conductive filler as a modified example. Although no thermally conductive filler is mentioned in another exemplary embodiment below, it is understood that the body (100) also includes a thermally conductive filler.

The bodies (100a, 100b) disposed above and below the base material (200) with the base material (200) therebetween may be connected to each other through the base material. That is, a portion of the base material may be removed, and a portion of the body (100) may be filled in the removed portion. Since at least a portion of the base material (200) is removed and the body is filled in the removed portion, the area of the base material (200) is reduced and the ratio of the body (100) is increased by the same amount. Therefore, the magnetic permeability of the power inductor can be increased.

2. Base material

The base material (200) may be provided in the body (100), for example, the base material (200) may be provided in the body (100) in a longitudinal direction of the body (100) (i.e., a direction toward the external electrode (400)), here, at least one base material (200) may be provided, for example, at least two base materials (200) may be spaced apart from each other by a predetermined distance in a direction perpendicular to a direction in which the external electrode (400) is provided (for example, in a perpendicular direction). alternatively, two or more base materials may be arranged in a direction in which the external electrode (400) is provided. for example, the base material (200) may be manufactured using a copper clad laminate (CC L) or a metal magnetic material, here, when the base material (200) is formed of a metal magnetic material, the magnetic permeability may be increased and a capacity may be easily achieved.e., CC L is manufactured by bonding a copper foil to a glass reinforced fiber, and since the CC L does not have a magnetic permeability, the power inductor may have a magnetic permeability that is deteriorated, while the base material may be manufactured using a metal-iron-silicon-iron-containing iron-metal alloy (200) having a predetermined thickness, and then a predetermined iron-nickel-iron-containing iron-metal-alloy-may be manufactured by bonding.

In addition, at least one via hole (210) may be defined in a predetermined region of the base material (200), and the coil patterns (310) and (320) disposed above and below the base material (200) may be electrically connected to each other through the via hole (210). The method for manufacturing the via hole (210) can comprise the following steps: a through hole (not shown) passing through the base material (200) in the thickness direction is formed in the base material (200) and then filled with paste. Here, at least one of the coil pattern (310) and the coil pattern (320) may be grown from the via hole (210), and thus, the via hole (210) and at least one of the coil pattern (310) and the coil pattern (320) may be integrated with each other. Additionally, at least a portion of the base material (200) may be removed. That is, at least a portion of the base material 200 may or may not be removed. Preferably, as shown in fig. 4 and 5, the remaining area of the base material 200 except for the area overlapping the coil patterns 310 and 320 may be removed. For example, the region of the base material 200 disposed within the coil patterns 310 and 320, respectively, having the spiral shape may be removed to define the through-holes 220, or the region of the base material 200 disposed outside the coil patterns 310 and 320 may be removed. That is, the base material 200 may have, for example, a racetrack shape along the outer shape of each of the coil patterns 310 and 320, and the area facing the outer electrode 400 may have a linear shape along the shape of the end of each of the coil patterns 310 and 320. Accordingly, the outer side of the base material (200) may have a curved shape with respect to the edge of the body (100). As shown in fig. 5, the body (100) may be filled in the portion of the base material (200) that has been removed. That is, the upper body (100a) and the lower body (100b) may be connected to each other through the removed region of the base material (200) including the through-hole (220). In addition, when the base material (200) is made of a metal magnetic material, the base material (200) may be in contact with the metal powder (110). To solve the above limitation, an inner insulating layer (510) (e.g., parylene) may be disposed on a side surface of the base material (200). For example, the inner insulation layer 510 may be disposed on the side surfaces of the through-hole 220 and on the outer surface of the base material 200. Here, the width of the base material 200 may be greater than the width of each of the coil patterns 310 and 320. For example, the base material (200) may remain a predetermined width directly under the coil pattern (310) and the coil pattern (320). For example, the base material (200) may protrude approximately 0.3 microns from the coil pattern (310) and the coil pattern (320). When regions of the base material 200 disposed inside and outside the coil patterns 310 and 320 are removed, the base material 200 may have a smaller region than the cross-section of the body 100. For example, when the cross-sectional area of the body (100) is approximately 100, the base material (200) may have an area ratio of approximately 40 to approximately 80. When the area ratio of the base material 200 is high, the magnetic permeability of the body may be reduced, and when the area ratio of the base material 200 is low, the formation areas of the coil patterns 310 and 320 may be reduced. Accordingly, the area ratio of the base material (200) may be adjusted in consideration of the magnetic permeability of the body (100), the line width and the number of turns of each of the coil patterns (310) and (320), and the like.

3. Coil pattern

The coil pattern (310, 320; 300) may be disposed on at least one surface of the base material (200), and preferably, may be disposed on both surfaces of the base material (200). Each of the coil patterns (310, 320) may have a spiral shape in an outward direction from a predetermined region of the base material (200), for example, from a central portion of the base material (200), and the two coil patterns (310, 320) disposed on the base material (200) may be connected to each other to form one coil. That is, the coil pattern 310 and the coil pattern 320 may have a spiral shape formed on the central portion of the base material 200 from the outside of the through hole 220, and may be connected to each other through the via hole 210 defined in the base material 200. Here, the upper coil pattern (310) and the lower coil pattern (320) may have the same shape and the same height. In addition, the coil patterns (310) and (320) may overlap each other. Alternatively, the coil pattern (320) may be disposed to overlap with a region on which the coil pattern (310) is not disposed. Each of the coil patterns (310) and (320) may have an end portion having a linear shape extending to the outside. The end portion may extend along a central portion of a short side of the body (100). As shown in fig. 4 and 5, the region of each of the coil patterns 310 and 320, which is in contact with the external electrode 400, may have a greater width than the other regions. Since a portion, i.e., a lead-out portion (lead out portion), of each of the coil pattern (310) and the coil pattern (320) has a wide width, a contact area between the coil pattern (310) and the coil pattern (320) and the external electrode (400) may be increased, and thus, resistance may be reduced. Alternatively, each of the coil patterns (310) and (320) may extend in a width direction of the external electrode (400) on one region on which the external electrode (400) is disposed. Here, an end portion of each of the coil pattern (310) and the coil pattern (320), i.e., a lead-out portion led out to the external electrode (400), may have a linear shape toward a central portion of a side surface of the body (100).

The coil pattern (310) and the coil pattern (320) may be electrically connected to each other through a via hole (210) defined in the base material (200). The coil pattern 310 and the coil pattern 320 may be formed by various methods, such as thick-film printing (thick-film printing), coating, deposition, plating, and sputtering. Here, the plating method is preferable. In addition, the coil patterns 310 and 320 and the via holes 210 may be made of a material including at least one of silver (Ag), copper (Cu), and a copper alloy. However, the exemplary embodiments are not limited thereto. When the coil pattern 310 and the coil pattern 320 are formed through a plating process, a coupling layer, such as a copper layer, is formed on the base material 200 through the plating process and then patterned through a photolithography process. That is, the copper layer may be formed using a copper foil disposed on the surface of the base material 200 as a seed layer, and then patterned to form the coil pattern 310 and the coil pattern 320. Alternatively, a photosensitive film pattern having a predetermined shape may be formed on the base material 200, a plating process may then be performed on the photosensitive film pattern to grow a coupling layer from the exposed surface of the base material 200, and the photosensitive film may then be removed, thereby forming the coil patterns 310 and 320 each having a predetermined shape. In addition, each of the coil patterns 310 and 320 may be formed to have a multi-layer structure. That is, a plurality of coil patterns may be further disposed above the coil pattern (310) disposed above the base material (200), and a plurality of coil patterns may be further disposed below the coil pattern (320) disposed below the base material (200). When the coil patterns 310 and 320 are formed to have a multi-layer structure, an insulating layer may be disposed between a lower layer and an upper layer. Then, a via hole (not shown) may be defined in the insulating layer to connect the multi-layered coil patterns to each other. The height of each of the coil patterns 310 and 320 may be approximately 2.5 times greater than the thickness of the base material 200. For example, the base material (200) has a thickness of approximately 10 microns to approximately 50 microns, and each of the coil patterns (310) and (320) may have a height of approximately 50 microns to approximately 300 microns.

In addition, each of the coil patterns 310 and 320 according to example embodiments may have a dual structure. That is, as shown in fig. 6, the coil pattern may include a first plating layer (300a) and a second plating layer (300b) covering the first plating layer (300 a). Here, the second plating layer (300b) covers the top surface and the side surface of the first plating layer (300 a). The thickness on the top surface of the second plating layer (300b) may be greater than the thickness on the side surface of the first plating layer (300 a). The first plating layer (300a) may have a predetermined inclination on a side surface thereof, and the second plating layer (300b) may have an inclination smaller than that of the side surface of the first plating layer (300 a). That is, the side surface of the first plating layer (300a) has an obtuse angle with respect to the surface of the base material (200) disposed outside the first plating layer (300a), and the angle of the second plating layer (300b) may be smaller than the angle of the first plating layer (300a), preferably, a right angle. As shown in fig. 7, the ratio between the width (a) of the top surface and the width (b) of the bottom surface of the first plating layer (300a) may be 0.2:1 to 0.9:1, preferably 0.4:1 to 0.8: 1. In addition, the ratio between the width (a) and the height of the first plating layer (300a) may be 1:0.7 to 1:4, preferably 1:1 to 1: 2. That is, the first plating layer (300a) may have a width gradually decreasing from the bottom surface to the top surface, and thus, the side surface may have a predetermined inclination. A main plating process may be performed, and then an etching process may be performed to have a predetermined inclination of the first plating layer (300 a). In addition, the second plating layer (300b) covering the first plating layer (300a) has an approximately rectangular shape in which the side surface is preferably formed vertically and a small circular portion is formed between the top surface and the side surface. Here, the shape of the second plating layer (300b) may be determined according to a ratio (i.e., a: b ratio) between the width (a) of the top surface of the first plating layer (300a) and the width (b) of the bottom surface of the first plating layer (300 a). For example, when the ratio a: b between the width (a) of the top surface of the first plating layer (300a) and the width (b) of the bottom surface of the first plating layer (300a) increases, the ratio between the width (c) of the top surface of the second plating layer (300b) and the width (d) of the bottom surface of the second plating layer (300b) increases. However, when the ratio a: b between the width (a) of the top surface of the first plating layer (300a) and the width (b) of the bottom surface of the first plating layer (300a) is greater than 0.9:1, the second plating layer (300b) may be formed such that the width of the bottom surface is greater than the width of the top surface and the side surface forms an acute angle with the base material (200). In addition, when a ratio a: b between a width of a top surface of the first plating layer (300a) and a width of a bottom surface of the first plating layer (300a) is less than 0.2:1, the second plating layer may be formed such that the top surface is rounded from a predetermined area of the side surface. Therefore, the ratio between the top surface of the first plating layer (300a) and the bottom surface of the first plating layer (300a) is preferably adjusted such that the top surface has a wide width and has vertical side surfaces. In addition, a ratio between the width (b) of the bottom surface of the first plating layer (300a) and the width (d) of the bottom surface of the second plating layer (300b) may be 1:1.2 to 1:2, and a ratio between the width (b) of the bottom surface of the first plating layer (300a) and the distance (e) between the respective first plating layers (300a) adjacent to each other may be 1.5:1 to 3: 1. Here, the second plating layers (300b) do not contact each other. A ratio between a width of a top surface and a width of a bottom surface of the coil pattern (300), which includes the first plating layer (300a) and the second plating layer (300b), may be 0.5:1 to 0.9:1, preferably 0.6:1 to 0.8: 1. That is, the ratio between the top surface and the bottom surface of the outer shape of the coil pattern (300), i.e., the outer shape of the second plating layer (300b), may be 0.5 to 0.9: 1. Accordingly, the circular area of the edge of the top surface of the coil pattern (300) may be less than approximately 0.5 relative to an ideal rectangular shape having right angles. For example, the circular area may be equal to or greater than approximately 0.001 and less than approximately 0.5 compared to an ideal rectangular shape with right angles. In addition, the resistance of the coil pattern (300) according to the exemplary embodiment does not vary greatly compared to an ideal rectangular shape. For example, when the ideal rectangular-shaped coil pattern has a resistance of approximately 100, the coil pattern (300) according to example embodiments may maintain a resistance of approximately 101 to approximately 110. That is, the coil pattern (300) according to an exemplary embodiment may maintain its resistance at approximately 101% to approximately 110% of that of an ideal rectangular-shaped coil pattern according to the shape of the first plating layer (300a) and the shape of the second plating layer (300b) that varies based on the shape of the first plating layer (300 a). The second plating layer (300b) may be formed using the same plating solution as the first plating layer (300 a). For example, the first plating layer (300a) and the second plating layer (300b) may use a plating solution based on copper sulfate and sulfuric acid, and the plating solution may have improved plating properties by adding chlorine (Cl) and an organic compound thereto. The organic compound may improve uniformity of a plating layer, electrodeposition characteristics, and gloss characteristics using a gloss agent (gloss agent) and a carrier including polyethylene glycol (PEG).

In the coil pattern (300), the second plating layer (300B) disposed on the first plating layer (300a) may have a lower width (a), a center width (B), and an upper width (C), at least a portion of the lower width (a), the center width (B), and the upper width (C) being different in a vertical direction of the second plating layer (300B). Here, the center width (B) may be equal to or greater than the lower width (a) and equal to or greater than the upper width (C). In addition, the lower width (a) may be equal to or greater than the upper width (C). For example, the center width (B) may be greater than each of the lower width (a) and the upper width (C) or equal to the lower width (a) and greater than the upper width (C). Alternatively, the lower width (a), the center width (B), and the upper width (C) may all be the same as one another. Here, the lower portion may refer to a height of approximately 10% of the height of the second plating layer (300b), the central portion may refer to a height of approximately 10% to approximately 80% of the height of the second plating layer (300b), and the upper portion may refer to a height up to the rounded portion.

In addition, the coil pattern (300) may be formed by laminating at least two plating layers. Here, each of the plating layers may have vertical side surfaces and the same shape and thickness. That is, the coil pattern 300 may be formed on the seed layer through a plating process. For example, the coil pattern (300) may be formed by laminating three plating layers on a seed layer. The coil pattern (300) may be formed by an anisotropic plating process (anisotropic plating process) and have an aspect ratio of approximately 2 to approximately 10.

In addition, the coil pattern (300) may have a shape in which a width is gradually decreased from an innermost circumference to an outermost circumference. That is, n coil patterns (300) having a spiral shape may be formed from the innermost circumference to the outermost circumference. For example, when four patterns are formed, the width of each of the patterns may gradually increase from the first pattern (i.e., the innermost peripheral pattern), the second pattern, the third pattern, and the fourth pattern (i.e., the outermost peripheral pattern). For example, when the first pattern has a width of 1, the second pattern may have a ratio of 1 to 1.5, the third pattern may have a ratio of 1.2 to 1.7, and the fourth pattern may have a ratio of 1.3 to 2. That is, the first to fourth patterns may have a ratio of 1:1 to 1.5:1.2 to 1.7:1.3 to 2. In other words, the width of the second pattern may be equal to or greater than the first pattern, the width of the third pattern may be greater than the first pattern and equal to or greater than the second pattern, and the width of the fourth pattern may be greater than each of the first pattern and the second pattern and equal to or greater than the third pattern. In order to increase the width of the coil pattern gradually from the innermost circumference to the outermost circumference, the seed layer may have a width gradually increasing from the innermost circumference to the outermost circumference. In addition, at least one region of the coil pattern may have a different width in a vertical direction. That is, the lower portion, the central portion, and the upper portion of at least one region may have different widths.

4. External electrode

External electrodes (410, 420; 400) may be disposed on two surfaces of the body (100) facing each other. For example, the external electrodes (400) may be disposed on both side surfaces of the body (100) facing each other in the X direction. The external electrode (400) may be electrically connected to the coil pattern (310, 320) of the body (100). In addition, the external electrode (400) may be formed on all of the two side surfaces of the body (100) and be in contact with the coil pattern (310) and the coil pattern (320) at central portions of the two side surfaces. That is, when the end of the coil pattern (310) and the end of the coil pattern (320) are exposed to the outside of the body (100) and the external electrode (400) is disposed on the side surface of the body (100), the external electrode (400) may be connected to the coil patterns (310, 320). The outer electrode (400) may be formed by various methods, such as deposition, sputtering, and plating, using a conductive epoxy and a conductive paste. The external electrode (400) may be disposed only on the two side surfaces and the bottom surface of the body (100) or even on the top surface or the front surface of the body (100). For example, the external electrodes (400) may be disposed on the front and rear surfaces in the Y direction and on the top and bottom surfaces in the Z direction in addition to the two side surfaces in the X direction. That is, the external electrodes (400) may be disposed on the two side surfaces in the X direction, on the bottom surface mounted on the printed circuit board, and on other areas depending on the formation method or process conditions. In addition, an external electrode (4)00) Can be determined by comparing, for example, approximately 0.5% to approximately 20% of Bi₂O₃Or SiO₂A multi-component glass frit (multi-component glass frit) as a main component is mixed with a metal powder to form. That is, a portion of the external electrode (400) contacting the body (100) may be made of a conductive material mixed with glass. Here, the mixture of the glass frit and the metal powder may be prepared in a paste form and applied to both surfaces of the main body (100). That is, when a portion of the external electrode (400) is made of a conductive paste, the conductive paste may be mixed with the glass frit. Since the frit is included in the external electrode (400), the adhesive force between the external electrode (400) and the body (100) may be improved, and the contact reaction between the coil pattern (300) and the external electrode (400) may be improved.

The external electrode (400) may be made of a conductive metal. For example, the outer electrode (400) may be made of at least one selected from the group consisting of: gold, silver, platinum, copper, nickel, palladium, and alloys thereof. Here, in an exemplary embodiment, at least a portion of the external electrode (400) connected to the coil pattern (300), i.e., the first layer (411, 421) disposed on the surface of the body (100) and connected to the coil pattern (300), may be made of the same material as the coil pattern (300). For example, the coil pattern (300) is made of copper, and at least a portion of the external electrode (400), i.e., the first layer (411, 421), may be made of copper. Here, as described above, the copper may be provided using a dipping or printing method using a conductive paste or using a method such as deposition, sputtering, and plating. However, in a preferred embodiment, at least the first layer (411, 421) of the external electrode (400) may be formed using the same method (i.e., plating) as the coil pattern (300). That is, the entire thickness of the external electrode (400) may be formed by copper plating, or a partial thickness of the external electrode (400), i.e., the first layer (411, 421) connected to the coil pattern (300) to be in contact with the surface of the body (100), may be formed by copper plating. In order to form the external electrode (400) through the plating process, the external electrode (400) may be formed by: a seed layer is formed on the two side surfaces of the body (100), and then a plating layer is formed from the seed layer. Alternatively, when the coil pattern (300) exposed to the outside of the body (100) is used as a seed, the external electrode (400) may be formed without forming a separate seed layer by plating. Here, the acid treatment process may be performed before the plating process. That is, at least a portion of the surface of the body (100) may be treated with hydrochloric acid and then a plating process may be performed. Although the external electrode (400) is formed by plating, the external electrode (400) may be disposed on the two side surfaces of the body (100) opposite to each other and may extend to the other side surfaces (i.e., the top and bottom surfaces) adjacent to the two side surfaces. Here, at least a portion of the external electrode (400) connected to the coil pattern (300) may be the entire side surface of the body (100) or a partial region of the body (100). Alternatively, the external electrode (400) may further include at least one plating layer. That is, the external electrode (400) may include a first layer (411, 421) connected to the coil pattern (300) and at least one second layer (412, 422) disposed on the first layer (411, 421). That is, the second layer (412, 422) may be one layer or two or more layers. For example, the external electrode (400) may be formed to further form at least one of a nickel plating layer (not shown) and a tin plating layer (not shown) on the copper plating layer. That is, the external electrode (400) may have a stacked structure formed of a copper layer, a nickel plated layer, and a tin plated layer, or may have a stacked structure formed of a copper layer, a nickel plated layer, and a tin/silver plated layer. Here, the plating may be performed by electroplating or electroless plating. That is, the first layer (411, 421) may be formed such that a part of the thickness is formed by electroless plating and the remaining thickness is formed by electroplating, or the entire thickness is formed by electroless plating or electroplating. That is, the second layer (412, 422) may be formed such that a part of the thickness is formed by electroless plating and the remaining thickness is formed by electroplating, or the entire thickness is formed by electroless plating or electroplating. Alternatively, the first layer (411, 421) may be formed by electroless plating or electroplating, and the second layer (412, 422) may be formed by electroless plating or electroplating in the same manner as the first layer (411, 421) or may be formed by electroless plating or electroplating in a different manner from the first layer (411, 421). The tin-plated layer of the second layer (412, 422) may have a thickness equal to or greater than the nickel-plated layer. For example, the outer electrode (400) may have a thickness of approximately 2 microns to approximately 100 microns, wherein the first layer (411, 421) may have a thickness of approximately 1 micron to approximately 50 microns, and the second layer (412, 422) may have a thickness of approximately 1 micron to approximately 50 microns. Here, in the external electrode (400), the first layer (411, 421) and the second layer (412, 422) may have the same thickness or different thicknesses. When the first layer (411, 421) and the second layer (412, 422) have different thicknesses, the first layer (411, 421) may be thicker or thinner than the second layer (412, 422). In an exemplary embodiment, the first layer (411, 421) has a smaller thickness than the second layer (412, 422). The second layer (412, 422) may be formed such that the nickel plating layer is formed to have a thickness of approximately 1 micron to approximately 10 microns, and the tin plating layer or the tin/silver plating layer is formed to have a thickness of approximately 2 microns to approximately 10 microns.

As described above, since at least a portion of the thickness of the external electrode (400) is made of the same material and the same method as the coil pattern (300), the coupling force between the body (100) and the external electrode (400) can be improved. That is, when at least a portion of the external electrode (400) is formed by copper plating, the coupling force between the coil pattern (300) and the external electrode (400) can be improved. In addition, since the external electrode (400) is disposed on a partial region of the body (100) in the Y direction and the Z direction to form a bent portion, a coupling force between the electrode (400) and the body (100) can be improved. The power inductor according to example embodiments may have a tensile strength of approximately 2.5 kilogram force (kgf) to approximately 4.5 kgf. Therefore, according to exemplary embodiments, the tensile strength may be further improved compared to the related art, and thus the body (100) may not be separated from the electronic device mounted with the power inductor according to exemplary embodiments. That is, the body (100) may not be separated from the external electrode (400) while the external electrode (400) maintains a state of being mounted to the electronic device.

5. Inner insulating layer

The inner insulating layer (510) may be disposed between the coil patterns (310) and (320) and the body (100) to insulate the coil patterns (310) and (320) from the metal powder (110). That is, the inner insulating layer 510 may cover top and side surfaces of the coil patterns 310 and 320. In addition, the inner insulating layer 510 may cover the base material 200 except for the top and side surfaces of the coil patterns 310 and 320. That is, the inner insulation layer 510 may be disposed on the exposed regions (i.e., the surface and the side surfaces of the base material 200) of the base material 200 from which the predetermined regions are removed, which are farther than the coil patterns 310 and 320. The inner insulating layer (510) on the base material (200) may have a thickness equal to that of the inner insulating layer (510) on the coil patterns (310, 320). The inner insulating layer (510) may be formed by coating parylene on the coil pattern (310) and the coil pattern (320). For example, when the base material (200) on which the coil pattern (310) and the coil pattern (320) are formed is prepared in a deposition chamber and then parylene is vaporized and provided into a vacuum chamber, parylene may be deposited on the coil pattern (310) and the coil pattern (320). For example, parylene may be primarily heated and vaporized into a dimer state in a vaporizer, and then secondarily heated and thermally decomposed into a monomer state, and when parylene is cooled using a cold trap (cold trap) connected to a deposition chamber and a mechanical vacuum pump, parylene may be converted from the monomer state into a polymer state and deposited on the coil pattern (310) and the coil pattern (320). Alternatively, the inner insulating layer (510) may be made of an insulating polymer other than parylene, for example, at least one selected from the group consisting of epoxy, polyimide, and liquid crystal polymer. However, when parylene is coated, the inner insulating layer 510 may be formed on the coil pattern 310 and the coil pattern 320 at a uniform thickness, and although parylene is formed at a small thickness, parylene may further improve insulating characteristics compared to other materials. That is, when parylene is coated to form the inner insulating layer (510), the inner insulating layer (510) may have a smaller thickness than when polyimide is coated to form the inner insulating layer (510) and the insulation breakdown voltage may be increased. Therefore, the insulation characteristics can be improved. In addition, a uniform thickness may be formed by filling a portion between the patterns according to a distance between the patterns of the coil pattern (310) and the coil pattern (320), or a uniform thickness may be formed along a stepped portion between the patterns. That is, when the distance between the patterns of the coil pattern (310) and the coil pattern (320) is large, parylene may be coated at a uniform thickness along the stepped portion between the patterns, and when the distance between the patterns is small, the portion between the patterns may be filled to form a predetermined thickness on the coil pattern (310) and the coil pattern (320). Fig. 8 is a cross-section showing a power inductor whose insulating layer is made of polyimide, and fig. 9 is a cross-section showing a power inductor whose insulating layer is made of parylene. As shown in fig. 9, in the case of parylene, the insulating layer has a small thickness along the coil pattern (310) and the stepped portion of the coil pattern (320). However, in the case of polyimide, the insulating layer has a larger thickness than in the case of parylene. By using parylene, the inner insulating layer (510) may have a thickness of approximately 3 microns to approximately 100 microns. When the inner insulating layer (510) made of parylene has a thickness less than approximately 3 micrometers, the insulating property may be deteriorated, and when the inner insulating layer (510) has a thickness greater than approximately 100 micrometers, as the thickness occupied by the inner insulating layer (510) within the same size increases, the volume of the body (100) may decrease, and thus the magnetic permeability may decrease. Alternatively, the inner insulating layer 510 may be manufactured as a sheet having a predetermined thickness and then formed on the coil patterns 310 and 320.

6. Surface insulating layer

A surface insulating layer (520) may be formed on a surface of the body (100). Here, the surface insulating layer (520) may be formed on the remaining surface of the body (100) except the two side surfaces opposite to each other. That is, the coil pattern (300) may be exposed to the two side surfaces (e.g., two side surfaces in the X direction) of the body (100) opposite to each other, and the surface insulation layer (520) may be formed on the remaining surfaces except the two side surfaces to which the coil pattern (300) is exposed. Word changing deviceFor example, the surface insulating layer (520) may be formed on two surfaces (i.e., front and rear surfaces) opposite to each other in the Y direction, and on two surfaces (i.e., bottom and top surfaces) opposite to each other in the Z direction, the surface insulating layer (520) may be formed to form the external electrode (400) at a desired position by a plating process, that is, since surface resistances are almost the same on the body (100), when the plating process is performed, the plating process may be performed on the entire surface of the body, and thus, when the surface insulating layer (520) is formed on a region on which the external electrode (400) is not formed, the external electrode (400) may be formed at a desired position, the surface insulating layer (520) may be made of an insulating material, for example, one selected from the group consisting of an epoxy resin, polyimide and a liquid crystal polymer (L), further, the surface insulating layer (520) may be made of a thermosetting epoxy resin, a thermosetting resin, or a thermosetting resin, such as a thermosetting resin, may be formed on the surface insulating layer 520, and the surface insulating layer 520 may be formed on the surface insulating layer (520) may be formed on the surface insulating layer, a surface insulating layer (520, a surface insulating layer (p-p type epoxy resin, p-₂) Silicon nitride layer (Si)₃N₄) And silicon oxynitride (SiON) layers. When the surface insulating layer (520) is formed of the above materialAs such, the surface insulating layer 520 may be formed by various methods, such as Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD). The surface insulating layer (520) may have a thickness equal to or different from the thickness of the external electrode (400), such as a thickness of approximately 3 microns to approximately 30 microns.

7. Coupling layer

A coupling layer (600) may be formed between the body (100) and the extended portion of the external electrode (400). That is, the external electrode (400) may extend in the Y direction and the Z direction (except for the two side surfaces of the body (100) in the X direction), and the coupling layer (600) may be formed between the body (100) and the extended portion of the external electrode (400). The coupling layer (600) may be formed such that the external electrodes (400) are securely formed on the four surfaces in the Y-direction and the Z-direction through a plating process. That is, since the surface insulating layer (520) is formed on the region (i.e., the bent portion) over which the external electrode (400) extends, the resistance of the region is greater than that of the side surface of the body (100), and thus the plating growth cannot be appropriately performed on the region. Therefore, the region of the external electrode (400) formed on the surface insulating layer (520) may have a smaller coupling force than the region of the external electrode (400) in contact with the body (100). Accordingly, the coupling layer 600 is formed to increase the coupling force and tensile strength so that the plating growth is properly performed even on the surface insulating layer 520. When the coupling layer (600) is formed on the surface insulating layer (520) of the curved portion and then the extension region of the external electrode (400) is formed, the coupling force of the external electrode (400) may be further improved compared to when the extension portion of the external electrode (400) is formed on the surface insulating layer (520). The coupling layer (600) is formed on the surface insulation layer (520) and then remains only on the bent portion through a polishing process for exposing the coil pattern (300). That is, the surface insulation layer (520) is formed on the entire top surface of the body (100), the coupling layer (600) is formed on all of the two side surfaces of the body (100) and a portion of the front, rear, top and bottom surfaces of the body (100), and then the two side surfaces of the body (100) are polished to expose the coil pattern (300). As a result, the coupling layer (600) remains on the bent portion. The coupling layer (600) may be formed by various methods, such as CVD, PVD, and plating. In addition, the coupling layer (600) may be formed of a metal, for example, gold (Au), lead (Pd), copper (Cu), and nickel (Ni), or an alloy of two or more of the above metals.

The coupling layer (600) may be formed by copper plating. Accordingly, the coil pattern (300), at least a portion of the external electrode (400), and the coupling layer (600) may be formed of the same material and by the same process. The coupling layer (600) may have a thickness smaller than that of each of the surface insulating layer (520) and the external electrode (400). For example, the coupling layer (600) may have a thickness smaller than that of the first layer (411, 421) of the external electrode (400).

8. Capping insulating layer

As shown in fig. 10, a cap insulating layer (530) may be formed on the top surface of the body (100) provided with the external electrode (400). That is, the cap insulating layer 530 may be formed on a top surface of the body 100, which is opposite to a bottom surface of the body 100 mounted on a Printed Circuit Board (PCB), for example, on a top surface in the Z direction. The top cap insulating layer (530) may be formed to prevent a short circuit between an external electrode (400) extending from a top surface of the body (100) and a shield can (shield can) or a short circuit between the power inductor and a circuit component located above the power inductor. That is, while the external electrodes (400) formed on the bottom surface of the body (100) are disposed adjacent to a Power Management Integrated Circuit (PMIC), the power inductor is mounted on a printed circuit board, wherein the PMIC has a thickness of approximately 1 mm and the power inductor also has the same thickness. PMICs may generate high frequency noise that affects surrounding circuits or components. Accordingly, the PMIC and the power inductor may be covered by a shield case made of a metal material (e.g., a stainless steel material). However, the power inductor may be short-circuited to the shield case by also providing an external electrode above the power inductor. Accordingly, when the cap insulating layer (530) is formed on the top surface of the body (100), a short circuit between the power inductor and an external conductive material can be prevented. The cap insulating layer (530) may be made of an insulating material (e.g.For example, the thermosetting resin may include at least one selected from the group consisting of novolac epoxy, phenoxy epoxy, BPA epoxy, BPF epoxy, hydrogenated BPA epoxy, dimer acid-modified epoxy, urethane-modified epoxy, rubber-modified epoxy, and DCPD epoxy.that the cap insulating layer (530) may be made of the insulating material (120) of the body (100) or a material for forming the surface insulating layer (520). the cap insulating layer (530) may be formed by impregnating the top surface of the body (100) in a polymer, a thermosetting resin, etc. accordingly, the cap insulating layer (530) may be formed on a part of the two side surfaces of the body (100) in the X direction and a part of the front and rear surfaces of the body (100) in the Y direction in addition to the top surface of the body (100). the cap insulating layer (530) may be made of a silicon oxide layer (530) such as a xylene oxide layer or a silicon oxide layer, for example₂) Silicon nitride layer (Si)₃N₄) And silicon oxynitride (SiON) layers. When the cap insulating layer 530 is formed of the above-described material, the surface insulating layer 520 may be formed by various methods such as CVD or PVD. When the cap insulating layer (530) is formed by CVD or PVD, the cap insulating layer (530) may be formed only on the top surface of the body (100). The cap insulating layer (530) may have a thickness for preventing a short circuit between the external electrode (400) of the body (100) and the shield can, for example, a thickness of approximately 10 microns to approximately 100 microns. Here, the cap insulating layer (530) may have a thickness equal to or different from that of the external electrode (400) and equal to or different from that of the surface insulating layer (520). For example, the cap insulating layer 530 may have a thickness greater than that of each of the outer electrode 400 and the surface insulating layer 520. Alternatively, the cap insulating layer 530 may have a thickness equal to that of each of the external electrode 400 and the surface insulating layer 520. In addition, a cap insulating layer (530) may be formed on the top surface of the body to have a uniform thickness to prevent the formation of cracksA stepped portion is maintained between the external electrode (400) and the body (100) or has a thickness on the top surface of the body (100) greater than a thickness on the top surface of the external electrode (400) to remove the stepped portion between the external electrode (400) and the body (100) so that the surface is flat. Alternatively, the cap insulating layer (530) may be separately formed at a predetermined thickness and then bonded to the body (100) using an adhesive (adhesive) or the like.

As described above, the power inductor according to the exemplary embodiment may improve the coupling force between the body (100) and the external electrode (400) by forming at least a partial thickness of the external electrode (400) in the same material and the same method as the coil pattern (300). That is, when the coil pattern (300) and the external electrode (400) are formed by copper plating, the coupling force between the coil pattern (300) and the external electrode (400) can be improved. Accordingly, the tensile strength may be further improved, and thus the body may not be separated from the electronic device mounted with the power inductor according to the exemplary embodiment. In addition, a coupling layer (600) may be formed between the surface insulating layer (520) and the external electrode (400) extending from the side surface of the body (100), i.e., the external electrode on the bent portion. When the coupling layer (600) is formed, since the plating growth is appropriately performed on the extension region of the external electrode (400), the coupling force may be improved, and thus the tensile strength may also be improved. When the cap insulating layer 550 is formed to prevent the external electrode (400) on the top surface of the body (100) from being exposed, the external electrode (400) may be prevented from contacting the shield can, and thus, a short circuit may be prevented from occurring between the external electrode (400) and the shield can. In addition, since the body (100) includes the heat conductive filler (130) in addition to the metal powder (110) and the insulating material (120), heat of the body (100) due to heating of the metal powder (110) may be discharged to the outside to prevent a temperature increase of the body (100), and thus restrictions such as a decrease in inductance may be prevented. In addition, since the inner insulating layer 510 is formed between the coil patterns 310 and 320 and the body 100 using parylene, the inner insulating layer 510 may be formed on the side and top surfaces of the coil patterns 310 and 320 with a small and uniform thickness and have improved insulating characteristics.

Manufacturing method

Fig. 11 to 17 are sectional views for sequentially explaining a method of manufacturing a power inductor according to an exemplary embodiment.

The coil pattern 310 and the coil pattern 320 may be formed on at least one surface of the base material 200 (preferably, one surface and the other surface of the base material 200) while the coil pattern 310 and the coil pattern 320 may be formed on the coil 320, the CC L or the metal magnetic material (preferably, a metal magnetic material capable of increasing the effective permeability and easily achieving the capacity) may be formed on the coil 320 and the coil pattern 320 may be formed on the coil 320 by a vacuum deposition process and a coil layer 320 may be formed on the coil 320, the insulating layer 310 may be formed on the coil 310 by a thermal deposition process, the insulating layer 320 may be formed on the coil 310 and the coil layer 320 may be formed on the coil 320, the coil layer 320 may be formed on the coil layer 320, the coil layer 320 may be formed by a thermal deposition process, the coil layer 320 may be formed on the coil layer 320 and the coil layer 320 may be formed on the coil layer 320, the coil layer 320 may be formed by a thermal deposition process, the same process, the coil layer 320 may be formed on the coil layer 320, the coil layer 320 may be formed by a coil layer 320, the coil layer 500, the coil layer may be formed by a thermal deposition process, the coil layer 320, the coil layer may be formed by a thermal deposition process, the layer 320, the layer may be formed by a thermal deposition process, the layer, the coil layer 320, the layer may be formed by a coil layer 320 may be formed by a coil layer 500, the layer is formed in the coil layer 500, the coil layer is formed in the coil layer 320, the coil layer is formed in the coil layer 500, the coil layer 320, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil layer 320, the coil layer 500, the coil layer is formed in the coil layer is formed in the coil layer 320, the coil layer 310, the coil layer 500, the coil layer 310, the coil layer 320, the coil layer 310, the coil layer is formed, the coil layer 500, the coil layer 310, the coil layer 500, the coil layer is formed in the coil layer 310, the coil layer 500, the coil layer 310, the coil layer is formed in the coil layer 310, the coil layer 500, the coil layer 310, the coil layer 500, the coil layer 320, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil layer 500, the coil layer 310, the coil layer 500, the coil layer 310, the coil layer 500, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil layer 320, the coil layer is formed in the coil, the coil layer 500, the coil layer is formed in the coil layer 500, the coil layer is formed in the coil, the coil layer is formed in the coil, the coil layer is formed in the coil, the coil layer is formed in the coil, the coil layer is formed in the coil layer is formed.

Referring to fig. 12, a plurality of sheets (100a to 100h) made of a material including metal powder (110), polymer (120), and thermally conductive filler (130) are prepared. Here, the metal powder (110) may use a metal material including iron (Fe), and the insulating material (120) may use epoxy resin and polyimide capable of insulating the metal powders (110) from each other. The heat conductive filler may use MgO, AlN, and a carbon-based material capable of discharging heat of the metal powder (110) to the outside. In addition, the surface of the metal powder (110) may be coated with a magnetic material, such as a metal oxide magnetic material or an insulating material (e.g., parylene). Here, the insulating material (120) may be included in a content of 2.0 wt% to 5.0 wt% based on 100 wt% of the metal powder (110), and the thermally conductive filler (130) may be included in a content of 0.5 wt% to 3 wt% based on 100 wt% of the metal powder (110). The plurality of sheets (100a to 100h) are respectively disposed above and below a base material (200) on which a coil pattern (310) and a coil pattern (320) are formed. The content of the heat conductive filler of the plurality of sheets (100a to 100h) may be different. For example, the content of the thermally conductive filler may gradually increase upward and downward from one surface and the other surface of the base material (200). That is, the content of the heat conductive filler of each of the sheets (100b and 100e) disposed above and below the sheets (100a and 100d) in contact with the base material (200) may be greater than the content of the heat conductive filler of each of the sheets (100a and 100d), and the content of the heat conductive filler of each of the sheets (100c and 100f) disposed above and below the sheets (100b and 100e) may be greater than the content of the heat conductive filler of each of the sheets (100b and 100 e). Since the content of the heat conductive filler is gradually increased in a direction away from the base material (200), the heat transfer efficiency can be more improved. A first magnetic layer (not shown) and a second magnetic layer (not shown) may be disposed above and below the uppermost sheet (100a) and the bottommost sheet (100h), respectively. The first and second magnetic layers may be made of a material having a higher magnetic permeability than the sheet materials (100a to 100 h). For example, the first and second magnetic layers may be made of magnetic powder and epoxy resin to have a higher magnetic permeability than that of the sheets (100a to 100 h). In addition, the first magnetic layer and the second magnetic layer may further include a thermally conductive filler.

Referring to fig. 13, the body (100) is formed such that a plurality of sheets (100a to 100h) with the base material (200) disposed therebetween can be laminated and pressed and then molded. Thus, the through-hole (220) and the removed portion of the base material (200) may be filled by the body (100). In addition, the body (100) and the base material (200) are cut into unit elements. The body (100) cut into unit elements may be molded or cured.

Referring to fig. 14, a surface insulating layer 520 is formed on the surface of the body 100. The surface insulating layer 520 may be formed by various methods including printing, dipping, and spraying. In addition, the surface insulating layer 520 may be formed using an insulating material, such as silicon, epoxy, organic coating solution, and glass frit, and may have a thickness of approximately 5 microns to approximately 40 microns. Here, the edge of the body may be polished before the surface insulating layer (520) is formed. That is, the edges may be chamfered by a polishing process to prevent the body (100) from cracking. Here, the edge of the body (100) may be formed to be inclined or rounded to have a predetermined angle rather than a right angle. Since the edge of the body (100) is inclined, the external electrode (400) can be formed with a uniform thickness. That is, when the edge of the body (100) has a right angle, the external electrode (400) may be formed on the edge in a thickness smaller than that of the surface, and thus a limit may occur in which the external electrode (400) is cut or the resistance increases. Therefore, since the edge is formed to be inclined, such a restriction can be prevented.

Referring to fig. 15, a coupling layer (600) is formed on a predetermined region on a body (100) on which a surface insulating layer (520) is formed. The coupling layer (600) may be formed on a region on which the external electrode (400) is to be formed. For example, when the external electrodes (400) are formed on both side surfaces of the body (100) opposite to each other in the X direction, the coupling layer (600) may be formed on both surfaces of the body (100) in the X direction and surfaces adjacent thereto in the Y direction and the Z direction. The coupling layer (600) may be formed by various methods, such as PVD, CVD, plating, dipping, and spraying. In addition, the coupling layer (600) may be made of a metal including gold (Au), lead (Pd), copper (Cu), and nickel (Ni) and an alloy of two or more of the above metals. That is, the coupling layer (600) may be made of a metal or a metal alloy in one layer or two or more layers. For example, the coupling layer (600) may be formed by at least one of a gold layer and a lead layer by PVD or CVD. As another example, the coupling layer (600) may be formed by plating, dipping, or spraying using a solution in which at least one of nickel and copper is melted or a solution in which one of gold and lead is melted. Since the gloss agent and the carrier including polyethylene glycol (PEG) are used for the solution in which the metal particles are melted, uniformity, electrodeposition characteristics, and gloss characteristics can be enhanced. The coupling layer 600 may be formed using the same material and the same method as the external electrode 400. That is, since the coupling layer (600) and the external electrode (400) are formed using the same material and the same method as each other, the coupling layer (600) and the external electrode (400) may have the same properties, and thus the coupling force between the coupling layer (600) and the external electrode (400) may be improved. For example, the coupling layer 600 may be formed by a copper plating process. Alternatively, in order to form the coupling layer 600 only on a partial region in the Y direction and the Z direction, the coupling layer 600 may be formed and then an etching process for removing a partial region of the coupling layer 600 may be performed or a predetermined mask may be formed and then the coupling layer 600 may be formed and the mask may be removed.

Referring to fig. 16, the coupling layer (600) and the surface insulating layer (520) disposed on a portion of the surface of the body are removed. That is, the coupling layer 600 and the surface insulation layer 520 on the region on which the external electrode 400 is to be formed are removed so that the external electrode is connected to the coil pattern 300. For example, the coupling layer (600) and the surface insulating layer (520) on both side surfaces of the body (100) facing each other in the X direction are removed. Here, the coupling layer (600) and the surface insulating layer (520) are removed to expose the coil pattern (300) to the side surface of the body (100). For example, a polishing process may be used to expose the coil pattern 300. Thus, the coupling layer (600) may remain on partial areas of the four surfaces of the body (100) in the Y-direction and the Z-direction.

Referring to fig. 17, external electrodes (400) may be formed on both ends of the body (100) of the unit cell such that the external electrodes (400) are electrically connected to the lead-out portions of the coil patterns (310) and (320). The external electrode (400) may extend from the two side surfaces of the body to which the coil pattern (300) is exposed to a surface of the body (100) adjacent to the two side surfaces. That is, the external electrode (400) may be formed on the two side surfaces of the body (100) and on the coupling layer (600) of the body (100) adjacent to the two side surfaces. Here, at least a portion of the external electrode (400) may be formed using the same material and the same method as the coil pattern (300). That is, the first layer (411, 421) may be formed by various methods such as electroless plating and electroplating, and the second layer (412, 422) may be formed from at least one layer by a plating process using nickel, tin, or the like. Here, the external electrode (400) may use the coil pattern (300) exposed to the outside of the body (100) as a seed. Since the coupling layer (600) is formed on the body (100) and the extension region (i.e., the bent portion) of the external electrode (400), the external electrode (400) can be properly formed on the bent portion and thus the coupling force of the bent portion can be improved. The first layer (411,421) may have a thickness of approximately 5 microns to approximately 40 microns,and the second layer (412, 422) may have a thickness of approximately 1 micron to approximately 20 microns. Additionally, when the second layer (412, 422) has two layers, e.g., a nickel-plated layer and a tin-plated layer, the nickel-plated layer can have a thickness of approximately 1 micron to approximately 10 microns, and the tin-plated layer can have a thickness of approximately 1 micron to approximately 10 microns. That is, the nickel plating layer may have the same thickness as the tin plating layer. Here, the plating solution for forming the first layer (411, 421) may use a solution in which approximately 5% sulfuric acid (H) is mixed₂SO₄) And approximately 20% copper sulfate (CuSO)₄) Or a plating solution having approximately 25% of an acid agent and approximately 3.5% of copper mixed therein. When at least a portion of the external electrode (400) is formed by copper plating, the coupling force of the external electrode (400) can become stronger. Here, a coupling force between the coil pattern (300) and the external electrode (400) may be greater than a coupling force between the body (100) and the external electrode (400). The cap insulating layer may be formed not to expose the external electrode (400) extending to the top surface of the body (100).

Examples of the experiments

According to an exemplary embodiment, since at least a portion of the external electrode (400) is formed by the same method as the coil pattern (300), i.e., copper plating, a coupling force between the external electrode (400), the coil pattern (300), and the body (100) may be improved. In addition, since the coupling layer (600) is formed on the extension region of the external electrode (400), i.e., under the external electrode (400) of the bent portion, the coupling force between the external electrode (400) and the body (100) can be improved. An exemplary embodiment in which a coupling layer (600) is formed on a bent portion and an external electrode is formed by copper plating is compared with a related art example in which an external electrode is formed by applying epoxy resin in terms of tensile strength.

First, an external electrode is formed to measure tensile strength, and then a wire is welded on the external electrode. Tensile strength is measured by pulling the soldered wire. That is, the tensile strength is measured when the body (100) is torn by pulling the wire or the external electrode (400) is separated from the body (100). Here, the external electrode is formed by applying epoxy resin in the prior art example, and the external electrode is formed by plating in the exemplary embodiment. Here, the coupling layer is not formed in the prior art example, and is formed in the exemplary embodiment. That is, although the external electrode is formed by applying the conductive epoxy in a state in which the surface insulating layer is formed in the related art example, the coupling layer is formed on a partial region on the surface insulating layer and then the external electrode is formed by a plating process in the exemplary embodiment. In addition, in the related art example and the exemplary embodiment, the shapes of the body, the base material, and the coil pattern are the same as each other. In addition, a plurality of power inductors according to the prior art examples and exemplary embodiments were manufactured, and then the tensile strength of each of the plurality of power inductors was measured. Thereafter, the average value of the measured tensile strengths was calculated.

Fig. 18 is a graph showing a state in which tensile strengths according to a related art example and an exemplary embodiment are compared. Here, the tensile strength means a force when the external electrode is separated from the body by increasing a force of pulling the wire. As shown in fig. 18, in the prior art example, a tensile strength of approximately 2.2 kgf to approximately 2.35 kgf was measured, and an average value of approximately 2.28 kgf was calculated. However, in the exemplary embodiment, a tensile strength of approximately 3.0 kgf to approximately 3.1 kgf is measured, and an average value of approximately 3.05 kgf is calculated. For reference, the ranges indicated in the figures refer to measurement ranges, and the points between the ranges refer to average values. Therefore, the tensile strength of the exemplary examples is approximately 30% to approximately 40% greater than that of the comparative examples. Accordingly, in exemplary embodiments, the coupling force between the external electrode and the body or the coil pattern may be improved, and thus, a restriction in which the body may be separated when the body is mounted to the electronic device may not be generated.

In an exemplary embodiment, the body may break when tension is continuously applied. That is, as shown in fig. 19, when the tension is continuously applied, the body may be broken. That is, the external electrode is separated from the body according to the tensile strength in the related art. However, in an exemplary embodiment, the body may be broken when the tension is continuously applied because the coupling force between the coil pattern and the external electrode is greater than the coupling force between the body and the external electrode. That is, in an exemplary embodiment, since a coupling force between the coil pattern and the external electrode is extremely large, the body and the external electrode may not be separated from each other although the body is broken. In addition, the body and the external electrode are strongly coupled to the bent portion through the coupling portion, and the external electrode of the bent portion is not separated.

Other embodiments

Hereinafter, other exemplary embodiments will be set forth. In another exemplary embodiment, a description overlapping with the detailed description in the above exemplary embodiment will be omitted. The detailed configuration of another exemplary embodiment is the same as that of the above-described exemplary embodiment unless otherwise stated. For example, in other exemplary embodiments, the external electrode (400) includes a first layer formed by copper plating and a second layer formed by nickel plating or tin plating. In addition, surface insulating layers (520) are formed on four surfaces except two side surfaces of the body (100) on which the external electrodes (400) are formed in a contact manner, and a coupling layer (600) is formed between an extended region of the external electrodes (400) and the surface insulating layers (520).

According to a second exemplary embodiment, the power inductor may further include at least one magnetic layer (not shown) disposed in the body (100). The magnetic layer may be disposed on at least one of the top surface and the bottom surface. In addition, at least one magnetic layer may be disposed in the body (100) between the base material (200) and the top or bottom surface of the body. Here, the magnetic layer may be provided to increase magnetic permeability of the body (100) and be made of a material having a larger magnetic permeability than the body (100). For example, the body (100) may have a permeability of approximately 20, and the magnetic layer may have a permeability of approximately 40 to approximately 1000. The magnetic layer can be manufactured using, for example, magnetic powder and an insulating material. That is, the magnetic layer may be made of a material having a larger magnetism than the magnetic material of the body (100) to have a high magnetic permeability, or may have a further larger content of the magnetic material. For example, in the magnetic layer, the insulating material may be added in an amount of approximately 1 wt% to approximately 2 wt% based on approximately 100 wt% of the metal powder. That is, the magnetic layer may include an amount of metal powder greater than an amount of metal powder of the body (100). The magnetic layer may further include a heat conductive filler (not shown) in addition to the metal powder and the insulating material. The thermally conductive filler may be included in a content of approximately 0.5 wt% to approximately 3 wt% based on approximately 100 wt% of the metal powder. The material used as the metal powder and the thermally conductive filler of the magnetic layer may be selected from the materials suggested in the description of the above exemplary embodiments. The magnetic layer may be manufactured in a sheet type and disposed on each of an upper portion and a lower portion of the body in which a plurality of sheets are stacked. In addition, the body (100) may be formed by printing a paste made of a material including the metal powder (110) and the polymer (120) or also including the heat conductive filler (130) at a predetermined thickness, or filling the paste into a frame and pressing the paste, and then the magnetic layer (710, 720) may be formed on each of the upper and lower portions of the body (100). Alternatively, the magnetic layer may be formed using a paste, i.e., by applying a magnetic material to the upper and lower portions of the body (100).

As described above, the power inductor according to another exemplary embodiment may include at least one magnetic layer in the body (100) to enhance a magnetic rate (magnetic rate) of the power inductor.

According to the third exemplary embodiment, at least two base materials (200) disposed in the body (100) may be provided, and the coil pattern (300) may be formed on one surface of each of the at least two base materials (200). In addition, an external electrode (400) is formed outside the body (100) such that the external electrode (400) is connected to the coil patterns (300) formed on each of the different base materials (200), and a connection electrode (not shown) may be formed outside the body to connect the coil patterns (300) formed on each of the different base materials (200). For example, the first external electrode may be formed to be connected to a first coil pattern formed on the first base material, the second external electrode may be formed to be connected to a third coil pattern formed on the second base material, and the connection electrode may be formed to be connected to a second coil pattern and a fourth coil pattern formed on the first base material and the second base material, respectively. Here, the connection electrode may be formed on, for example, at least one surface of the body (100) on which the external electrode (400) is not formed in the Y direction. In addition, the connection electrode may be formed using the same material and the same process as the external electrode (400).

As described above, the capacity of the power inductor according to the third exemplary embodiment may be increased such that at least two base materials (200), each of which is formed with the coil pattern (300) on at least one surface, are spaced apart from each other in the body (100), and a plurality of coil patterns are formed when the coil patterns (300) formed on each of the different base materials (200) are connected by the connection electrodes outside the body (100). That is, by using the connection electrodes outside the body (100), the coil patterns (300) respectively formed on different base materials (200) may be connected to each other in series, and thus the capacity of the power inductor in the same area may be increased.

According to a fourth exemplary embodiment, the power inductor may comprise: at least two base materials (200) vertically disposed in the body (100); a coil pattern (300) formed on at least one surface of each of the at least two base materials (200); and an external electrode (400) disposed outside the body (100) and connected to the coil patterns (300) respectively formed on the at least two base materials (200). For example, the plurality of base materials (200) may be spaced apart from each other in a longitudinal direction perpendicular to a thickness direction of the body (100). That is, although the plurality of base materials (200) are arranged in the thickness direction (e.g., vertical direction) of the body (100) according to still another exemplary embodiment, the plurality of base materials (200) are arranged in the direction (e.g., horizontal direction) perpendicular to the thickness direction of the body (100) according to still another exemplary embodiment. In addition, the external electrode (400) may be connected to each of the coil patterns (300) respectively formed on the plurality of base materials (200). For example, each of the first and second external electrodes facing each other is connected to the coil pattern formed on the first base material, each of the third and fourth external electrodes spaced apart from the first and second external electrodes is connected to the coil pattern formed on the second base material, and each of the fifth and sixth external electrodes spaced apart from the third and fourth external electrodes is connected to the coil pattern formed on the third base material. That is, the external electrodes (400) are connected to the coil patterns (300) respectively formed on the plurality of base materials (200).

As described above, the power inductor according to the fourth exemplary embodiment may achieve a plurality of inductors in one body (100). That is, since at least two base materials (200) are arranged in a horizontal direction and coil patterns (300) respectively formed on the at least two base materials (200) are connected to external electrodes (400) different from each other, the plurality of inductors are arranged in parallel to each other, and thus at least two power inductors are achieved in one body (100).

According to the fifth exemplary embodiment, at least two base materials (200) are laminated while being spaced apart by a predetermined distance in a thickness direction (e.g., a vertical direction) of the body (100), and the coil patterns (300) formed on the base materials (200) are drawn in different directions from each other and are respectively connected to the external electrodes (400). That is, although the plurality of base materials (200) are arranged in the horizontal direction according to still another exemplary embodiment, the plurality of base materials (200) are arranged in the vertical direction according to still another exemplary embodiment. Therefore, according to still another exemplary embodiment, since at least two base materials (200) are arranged in the thickness direction of the body (100) and the coil patterns (300) respectively formed on the base materials (200) are connected by the external electrodes (400) different from each other, the plurality of inductors are disposed in parallel to each other, and thus at least two power inductors are achieved in one body (100).

As described above, according to the third to fifth exemplary embodiments, the plurality of base materials (200), each of which has the coil pattern (300) formed on at least one surface, are laminated in the thickness direction (i.e., the vertical direction) of the body (100) or arranged in the direction perpendicular to the thickness direction (i.e., the horizontal direction). In addition, the coil patterns (300) respectively formed on the plurality of base materials (200) may be connected to the external electrode (400) in series or in parallel. That is, the coil patterns (300) respectively formed on the plurality of base materials (200) may be connected in parallel to the external electrodes (400) different from each other, and the coil patterns (300) respectively formed on the plurality of base materials (200) may be connected in series to the same external electrode (400). In the case of the series connection, the coil patterns (300) respectively formed on the base material (200) may be connected to an external electrode through a connection electrode outside the body (100). Thus, in the case of parallel connection, two external electrodes (400) are required for each of the plurality of base materials (200), and in the case of series connection, two external electrodes (400) are required and at least one connection electrode is required regardless of the number of base materials (200). For example, when the coil patterns (300) formed on the at least three base materials (200) are connected to the external electrodes (400) in parallel, six external electrodes (400) are required, and when the coil patterns (300) formed on the at least three base materials (200) are connected to the external electrodes (400) in series, two external electrodes (400) and at least one connection electrode are required. In addition, a plurality of coils are provided in the body (100) in the case of parallel connection, and one coil is provided in the body (100) in the case of series connection.

According to an exemplary embodiment, a power inductor including at least one base material (200) having a coil pattern (300) formed thereon and disposed in a body (100) is set forth as an example. However, the exemplary embodiments can be applied to all chip assemblies in which external electrodes are formed on the surface of the body. For example, the exemplary embodiments may be applied to components for forming external electrodes, such as a chip component in which an inductor and a capacitor are formed and a chip component in which an electrostatic discharge (ESD) protection unit (e.g., a variable resistor (varistor) or a suppressor (suppressor)) is formed. That is, an exemplary embodiment may include: a body; the conducting layer is arranged in the body; an external electrode disposed outside the body to be connected to the conductive layer; a surface insulating layer formed on the remaining surface except the surface connecting the conductive layer to the external electrode; and a coupling layer disposed between the extension region of the external electrode and the surface insulating layer. Here, the conductive layer may be a coil pattern, a plurality of internal electrodes of a capacitor spaced apart from each other by a predetermined distance, and a discharge electrode in a variable resistor or suppressor, which are set forth in exemplary embodiments. Alternatively, the external electrode may be formed outside the body in which all of the coil pattern, the internal electrode, and the discharge electrode are formed.

In addition, the exemplary embodiments may be applied to an inductor including a winding type coil formed in a body. That is, as shown in fig. 20 to 23, the exemplary embodiment may be applied to a winding type inductor including an external electrode (400) located outside a body (100) in which a winding type coil (300a) is disposed between an upper body (100a) and a lower body (100b), and in which a metal magnetic powder and an epoxy resin are mixed in the body (100). Fig. 20 to 22 are perspective views sequentially showing a manufacturing process to explain other exemplary embodiments applied to the winding type inductor, and fig. 23 is a sectional view.

As shown in fig. 20, a receiving portion in which the winding type coil (300a) is received is defined in the lower body (100b), and the upper body (100a) is disposed above the lower body (100b) to cover the receiving portion. An extraction portion (300b) may be defined in an outer surface of the lower body (100b), and the winding type coil (300a) is extracted through the extraction portion (300 b). Here, although not shown, the winding type coil (300a) and the lead-out portion (300b) may be coated with an inner insulating layer. When the upper body (100a) covers the lower body (100b) and then presses the lower body (100b), the body (100) may be filled in a space defined by the winding type coil (300 a). For example, the upper body (100a) may be formed to fill the inner space of the winding type coils (300a) and the space between the winding type coils (300a) by pressing the body (100).

As shown in fig. 21, the body (100) is polished and resized. That is, the body (100) is sized by polishing four or six surfaces of the body (100). Here, the lead-out portion of the winding type coil (300a) may be partially polished, and thus the thickness of the lead-out portion may be reduced.

As shown in fig. 22, the external electrode (400) may be provided on the lead-out portion (300a), where the external electrode (400) may extend from the side surface to only the bottom surface of the body (100), that is, the external electrode (400) may have, for example, "L" -shape, alternatively, the external electrode (400) may extend to adjacent four surfaces in addition to the side surface, where a surface insulating layer (520) is formed on a region on which the external electrode (400) is not formed, that is, on the top and bottom surfaces of the body (100) in the Z direction and on the front and rear surfaces of the body (100), a coupling layer (600) is formed on the bottom surface of the body (100) in the Z direction, and then the external electrode (400) is formed on the side surface of the body (100) and the coupling layer (600), where a surface insulating layer (520) and a coupling layer (600) may be first formed on the upper body (100a) and the lower body (100b) before embedding the winding-type coil (300a), that is, that the coupling layer (600) and the upper surface layer (510) and the lower coupling layer (510) may be formed on the upper body (100a) and the lower body (100b), and the coupling layer (510 b) may be formed on the upper body (100b), and the lower coupling layer (510 b) may be formed on the upper body (100b), and the outer coupling layer (510) may be formed on the upper body (100b), and the outer surface of the outer coupling layer (100b), and the outer coupling layer (100 b).

In a power inductor according to example embodiments, a coupling layer (600) may not be formed on at least a portion of the power inductor, and at least a portion of a surface insulation layer (520) may be removed. For example, as shown in fig. 24, the surface insulating layer 520 may not be formed on a region to which the external electrode 400 extends. That is, the surface insulating layer 520 may be formed only on the surface of the body on which the external electrode 400 is not formed. Thus, the external electrode (400) and the extension region of the external electrode (400) may be in contact with the surface of the body (100). In addition, as shown in fig. 25, the surface insulating layer (520) may not be formed on at least a portion of the region to which the external electrode (400) extends. That is, although the surface insulating layer 520 is formed on one portion of the region to which the external electrode 400 extends, the surface insulating layer 520 may not be formed on another portion of the region. For example, the surface insulating layer 520 may not be formed on a portion of the top surface of the body 100 to which the external electrode 400 extends, and may be formed on a portion including the bottom surface of the body 100 to which the external electrode 400 extends. Thus, one portion of the extended region of the external electrode (400) may be in contact with the surface insulating layer (520), and the other portion may be in contact with the body (100). Here, the coupling layer (600) may be formed between the surface insulation layer (520) and the extension region of the external electrode (400). In addition, as shown in fig. 26, the outer electrode (400) may not extend to a partial region. That is, even in the case of the thin film type power inductor, the external electrode (400) may not extend to the top surface of the body (100) but may extend only to the region including the bottom surface of the body (100) as in the winding type inductor in fig. 23. Here, the surface insulating layer 520 may be formed on the entire top surface of the body 100 to which the external electrode 400 does not extend, and may be formed on a region on which the external electrode 400 is not formed, including the bottom surface of the body 100 to which the external electrode 400 extends. That is, the surface insulating layer 520 may not be formed on the region on which the external electrode 400 is formed. Thus, the external electrode (400) may be in contact with the surface of the body (100). However, although not shown in the drawings, the surface insulating layer 520 may be formed on a portion to which the external electrode 400 extends, and the coupling layer 600 may be formed between the surface insulating layer 520 and the portion.

This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Accordingly, those skilled in the art will readily appreciate that various modifications and changes may be made to the present invention without departing from the spirit and scope of the invention as defined by the appended claims.