Magnetic component

Abstract

A magnetic component according to one embodiment of the present invention may comprise: a bobbin; a first core and a second core disposed to face each other on the bobbin; and a coil part arranged between the first core and the second core, wherein the coil part includes a first terminal portion and a second terminal portion that pass through the bobbin from the upper surface to the lower surface of the bobbin, the first terminal portion and the second terminal portion including, in at least a portion of the respective lower surfaces of the first terminal portion and the second terminal portion, regions processed to be recessed from the lower surface toward the upper surface of the bobbin, wherein a soldering cap that fully covers the lower surfaces of the first terminal portion and the second terminal portion can be included on the lower surface of each of the first terminal portion and the second terminal portion.

Description

magnetic components

[0001] The present invention relates to a magnetic component, and more specifically, to a magnetic component in which a groove in the shape of an engraved portion is formed on the lower surface of a terminal portion of a coil portion to improve solder paste coating performance, thereby stably forming a soldering cap on a cut surface of a coil portion having a double structure.

[0002] Typically, vehicles equipped with electric motors are equipped with a high-voltage battery for the electric motor and an auxiliary battery to power the electrical load. The auxiliary battery can be charged using the power from the high-voltage battery. To charge the auxiliary battery, the DC power from the high-voltage battery must be converted to match the voltage of the auxiliary battery. For this purpose, a DC-DC converter can be used.

[0003] The DC converter is placed between the first battery and the second battery and may include a drive circuit, a transformer, and an output circuit.

[0004] The primary battery outputs DC voltage and current, which the drive circuit converts into time-varying AC current and supplies to the primary coil of a transformer. The transformer converts AC voltage and current, and the output circuit converts the AC current output from the transformer into DC current and transmits it to the secondary battery.

[0005] The output circuit typically consists of an output inductor and a capacitor. The output inductor is designed with margins to withstand the high current delivered from the transformer. For high-capacity inductors exceeding 2 kW, square coils with a rectangular cross-section are primarily used.

[0006] These flat coils utilize screw fastening for mounting on a circuit board. However, because they rely on pressurized contact between the screw and the terminal, they are susceptible to deterioration and performance degradation due to increased contact resistance. Furthermore, the use of extension cords or bus bars increases their bulk and requires separate fixing devices.

[0007] In addition, flat coils are manufactured from copper (Cu) and have the disadvantage of higher material costs compared to circular coils due to their large volume.

[0008] Therefore, a mounting technology that can directly solder the output inductor terminal to the substrate and an inductor technology that can reduce material costs are required.

[0009] The technical problem to be solved by the present invention is to provide a magnetic component that can stably form a soldering cap on the cut surface of a coil portion having a double structure by forming a concave groove on the lower surface of the terminal portion of the coil portion to improve solder paste coating performance.

[0010] The technical task of the present invention is to provide a magnetic component that can expand the heat dissipation area and soldering contact area of ​​a coil portion and reduce the material cost of the coil portion.

[0011] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] According to one embodiment of the present invention for solving the above technical problem, a magnetic component includes: a bobbin; a first core and a second core arranged facing each other on the bobbin; and a coil portion arranged between the first core and the second core, wherein the coil portion includes a first terminal portion and a second terminal portion penetrating the bobbin from an upper surface to a lower surface of the bobbin, and the first terminal portion and the second terminal portion each include a region concavely processed from the lower surface to the upper surface of the bobbin on at least a portion of a lower surface thereof, and a soldering cap may be formed on the lower surface of each of the first terminal portion and the second terminal portion, which covers the entire lower surface of the first terminal portion and the second terminal portion, including the concavely processed region.

[0013] In one or more embodiments, the bobbin may include a first through hole in which the coil portion is mounted, and two second through holes spaced apart from the first through hole and through which the first terminal portion and the second terminal portion pass.

[0014] In one or more embodiments, the coil of the coil portion may include a second conductive layer of a different material from the first conductive layer inside the first conductive layer.

[0015] In one or more embodiments, the first terminal portion and the second terminal portion may include a protrusion in which the lower surface of the first conductive layer protrudes further than the lower surface of the second conductive layer.

[0016] In one or more embodiments, the soldering cap may include a skirt portion that forms a coating film of a certain thickness to surround an outer surface of the first conductive layer, and a bridge portion that is connected to the skirt portion and is inserted into a groove portion of the second conductive layer to form a coating film of a certain thickness.

[0017] In one or more embodiments, the concavely machined area may be a groove-machined portion of the second conductive layer.

[0018] In one or more embodiments, the concavely processed area may be a V-groove cut or a grid-groove cut on the lower surface of the first terminal portion and the second terminal portion.

[0019] In one or more embodiments, the skirt length of the soldering cap may be formed longer than the groove depth of the second conductive layer.

[0020] In one or more embodiments, the coil of the coil portion has a polygonal cross-section and a chamfered portion is formed at a corner of the polygon, and at least a portion of the coil portion seated in the first through hole forms a contact surface that contacts the heat dissipation member, and at least a portion of the contact surface can be wound to form a groove into which the heat dissipation member is inserted by the opposing chamfered portions of neighboring coils.

[0021] In one or more embodiments, the thickness (T1) of the first conductive layer may be 0.05 mm ≤ T1 ≤ 0.25 mm, and the ratio of the thickness (T2) of the second conductive layer to the thickness (T1) of the first conductive layer may be 70 to 90 (T2): 10 to 30 (T1).

[0022] The magnetic component according to the present invention forms a concave groove on the lower surface of the terminal portion of the coil portion to improve solder paste coating performance, thereby stably forming a soldering cap on the cut surface of the coil portion having a double structure.

[0023] The magnetic component according to the present invention can also prevent corrosion and peeling at the cut surface of the coil portion and prevent PCB mounting defects.

[0024] The magnetic component according to the present invention also improves product performance by expanding the heat dissipation area of ​​the coil portion through structural improvement, and reduces manufacturing costs by configuring the coil portion with a second conductive layer made of a low-cost material and a first conductive layer made of copper.

[0025] FIG. 1 is a front perspective view of a magnetic component according to one embodiment of the present invention.

[0026] Figure 2 is a bottom perspective view of a magnetic component according to one embodiment of the present invention.

[0027] Figure 3 is an exploded perspective view of a magnetic component according to one embodiment of the present invention.

[0028] Figure 4 is a plan view of a magnetic component according to one embodiment of the present invention.

[0029] Figure 5 is a bottom view of a magnetic component according to one embodiment of the present invention.

[0030] Figure 6 is a front view showing a mounted state of a magnetic component according to one embodiment of the present invention.

[0031] Figure 7 is a side view showing a mounted state of a magnetic component according to one embodiment of the present invention.

[0032] Fig. 8 is a cross-sectional view of a coil portion according to one embodiment of the present invention.

[0033] Figure 9 is a graph of the content ratio with respect to the second conductive layer according to the change in the thickness of the first conductive layer of the coil portion according to one embodiment of the present invention.

[0034] Fig. 10 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the first embodiment of the present invention.

[0035] Fig. 11 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the first embodiment of the present invention.

[0036] Fig. 12 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the second embodiment of the present invention.

[0037] Fig. 13 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the second embodiment of the present invention.

[0038] Fig. 14 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the third embodiment of the present invention.

[0039] Fig. 15 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the third embodiment of the present invention.

[0040] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0041] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0042] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly" or "electrically connected" with other members or components in between.

[0043] Additionally, throughout the specification, the description that each layer (film), region, pattern or structure is formed "on" or "under" the substrate, each layer (film), region, pad or pattern includes both being formed directly or through the interposition of another layer. The criteria for being on / over or under / under each layer are explained based on the drawings.

[0044] Additionally, expressions such as 'first, second', etc. are used only to distinguish between multiple components, and do not limit the order or other characteristics between the components.

[0045] In addition, the flowcharts illustrated in the drawings are merely exemplary sequences for obtaining the most desirable results in carrying out the present invention, and it is obvious that other steps may be added or some steps may be deleted.

[0046] Additionally, expressions for numerical ranges described as between A and B should be understood as A or more and B or less.

[0047] Additionally, the expression for a C configuration placed between A and B should be understood to include not only the extent to which the C configuration is located between the A configuration and the B configuration along the vertical and / or horizontal direction, but also the extent to which it overlaps with A and / or B along the vertical and / or horizontal direction.

[0048] Additionally, an expression such as "composition A "covers" composition B should not only mean that composition A completely covers composition B, but also that A covers at least part of B.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0050] Hereinafter, a preferred embodiment of the present invention will be described with reference to the attached drawings.

[0051] FIG. 1 is a front perspective view of a magnetic component according to one embodiment of the present invention, FIG. 2 is a bottom perspective view of a magnetic component according to one embodiment of the present invention, FIG. 3 is an exploded perspective view of a magnetic component according to one embodiment of the present invention, FIG. 4 is a plan view of a magnetic component according to one embodiment of the present invention, and FIG. 5 is a bottom view of a magnetic component according to one embodiment of the present invention.

[0052] Referring to FIGS. 1 to 5, a magnetic component according to one embodiment of the present invention may be a magnetic component including an inductor. The magnetic component may largely include a bobbin (130), a core portion (110), and a coil portion (120).

[0053] The bobbin (130) is positioned below the core portion (110) and the coil portion (120) and functions to support the core portion (110) and the coil portion (120), and the upper surface of the bobbin (130) may at least partially overlap the lower surface of the core portion (110) in a vertical direction (e.g., in the Z-axis direction).

[0054] The bobbin (130) may be formed as a flat support plate (131). A first through hole (132) may be formed in the center of the support plate (131), and a second through hole (133, 134) may be formed at a position spaced apart from the first through hole (132).

[0055] The support plate (131) may be a rectangular plate with a horizontal side and a vertical side forming a right angle. The first through hole (132) may be a rectangular hole located at the center of the support plate (131). The first through hole (132) may be formed with a larger area than the second through holes (133, 134). By allowing a portion of the coil unit (120) to hang over and be settled within the first through hole (132), the coil unit (120) may be supported more stably. In addition, by having a larger area than the second through hole (133, 134), the heat dissipation effect of the coil unit (120) may be improved.

[0056] The first through hole (132) and the second through holes (133, 134) are spaced apart from each other. When the first through hole (132) and the second through hole (133, 134) are connected, the area occupied by the through hole in the bobbin may become excessively large, which may deteriorate the strength of the bobbin, and an electrical short circuit problem may occur between the terminals introduced into the first through hole (132) and the second through hole (133, 134) and some coil parts. Therefore, it is preferable that the first through hole (132) and the second through hole (133, 134) be spaced apart from each other.

[0057] The coiled body of the coil part (120) can be placed in the first through hole (132). A portion of the body part can be exposed outside the first through hole (132). At this time, a portion of the coil part (120) is slightly fitted into the first through hole (132), thereby helping heat dissipation. In addition, a portion of the coil part (120) is placed over the inside of the first through hole (132), thereby securing structural stability in which the coil part (120) is more stably supported on the bobbin (130).

[0058] The bobbin (130) can be made of a material with excellent thermal conductivity, and the heat generated in the coil portion (120) is conducted to the bobbin and released to the outside, so that the bobbin can function as a heat sink.

[0059] Materials with excellent thermal conductivity include, but are not necessarily limited to, aluminum and copper.

[0060] FIG. 6 is a front view showing a mounted state of a magnetic component according to one embodiment of the present invention, and FIG. 7 is a side view showing a mounted state of a magnetic component according to one embodiment of the present invention.

[0061] Referring to FIGS. 6 and 7, a heat dissipation member (P) may be applied through the first through hole (132) of the bobbin (130) to improve heat dissipation efficiency. The applied heat dissipation member (P) fills the first through hole (132) and covers and contacts the coil portion (120), thereby allowing heat generated in the coil portion (120) to be quickly transferred to the bobbin (130).

[0062] At this time, thermal paste can be used as a heat dissipation member (P).

[0063] The second through hole (133, 134) may be a square-shaped hole formed at a location spaced apart from the first through hole (132).

[0064] The second through hole (133, 134) is formed so that the first terminal portion (121) and the second terminal portion (122) of the coil portion (120) pass through, and these terminal portions not only supply current to the magnetic component, but also can serve as a guide to guide the mounting position on the PCB (200).

[0065] The first terminal portion (121) and the second terminal portion (122) can be kept apart from the wound body portion of the coil portion (120) by the second through-hole (133, 134) which is spaced apart from the first through-hole (132), thereby preventing a short-circuit problem.

[0066] Referring to FIG. 5, when the distance from the center line (CL) of the first through hole (132) to the parallel sides of both sides of the first through hole (132) is referred to as a first distance (L1), and the distance from the center line (CL) to the parallel outermost sides of the second through hole (133, 134) is referred to as a second distance (L2), the first distance (L1) and the second distance (L2) may be different from each other. That is, the second through holes (133, 134) are arranged more or less adjacent to the first through hole (132) and the outer surface of the bottom surface of the bobbin (130), respectively, thereby preventing electrical short circuits between the first and second terminal portions (121, 122) and the coil portion (120) arranged in the first through hole (132), and improving heat dissipation function. According to one embodiment, in order to prevent electrical short circuits and increase heat dissipation, the first distance (L1) may be smaller than the second distance (L2).

[0067] The second through hole (133, 134) may be formed further outward than the first through hole (132). In addition, the second through hole (133, 134) may be formed on both sides diagonally centered around the first through hole (132).

[0068] At this time, the second through holes (133, 134) can be formed independently at a certain distance from the first through hole (132).

[0069] Referring to FIGS. 6 and 7, the bobbin (130) may have a leg portion (135) formed so as to be spaced apart from the surface of the PCB (200). The leg portion (135) may be formed at each of the four corners of the support plate (131) of the bobbin (130).

[0070] The bobbin (130) can be vertically spaced apart from the PCB (200) by a plurality of spaced-apart leg portions (135), and the space where the PCB (200) and the bobbin (130) are spaced apart can be exemplarily referred to as a ventilation portion (G). The ventilation portion (G) can function as an exhaust window to discharge fumes generated during the process of soldering the first terminal portion (121) and the second terminal portion (122) of the coil portion (120) to the PCB (200) using solder paste (S) and other processes.

[0071] At this time, the first and second terminal portions (121, 122) may extend longer than the leg portion (135) in the vertical direction. The first and second terminal portions (121, 122) may be soldered using solder paste (S) while being inserted through a hole formed in the PCB (200). At this time, the solder paste (S) may contain a lead component.

[0072] A magnetic component (100) according to one embodiment of the present invention may include a core portion (110). The core portion (110) may include a first core (111) and a second core (111') that are arranged facing each other on a bobbin (130).

[0073] The core portion (110) may be formed by first and second cores (111, 112) that are symmetrical on both sides and connected to each other. In this case, the first and second cores (111, 112) may be “E”-shaped cores.

[0074] Additionally, the core portion (110) may include a magnetic material. For example, the core portion (110) may include a Mn-Zn-based ferrite, and the permeability (μ) of the ferrite may be 2,000 to 15,000, but is not necessarily limited thereto.

[0075] The core portion (110) may include a conductive metal, for example, copper or aluminum, and may be formed by winding at least one metal conductor (i.e., a square wire) having a polygonal cross-sectional shape around the center of the core portion (110). One metal conductor forms one coil, and both ends of the conductor may correspond to terminals for fixing and conducting current with other components, such as a substrate of a device including a magnetic component (e.g., a DC converter).

[0076] Hereinafter, the shapes of the cores (111, 111') constituting the core portion (110) will be described with reference to FIGS. 1 to 3. Since the core portion (110) is composed of a pair of first and second cores (111, 111') that are symmetrical left and right, the following description will be based on the first core (111).

[0077] The first core (111) may be provided with a rectangular shaped opposing plate portion (112). A cylindrical middle leg (113) may be formed protrudingly at the center of the opposing plate portion (112), and a pair of outer legs (114) may be formed protrudingly at both ends of the opposing plate portion (112).

[0078] At this time, the protrusion heights of the middle foot (113) and the outer foot (114) may be the same, or the outer foot (114) may be formed to protrude higher than the middle foot (113).

[0079] The intermediate portion (113) serves as a coupling axis to which the winding portion (121) of the coil portion (120) is axially coupled, and can be formed with a diameter equal to or smaller than the inner diameter of the coil portion (120).

[0080] In forming the core portion (110), the intermediate portion (113) formed in one core (111) and the intermediate portion (113) formed in another core (111) may face each other and contact each other, or may be spaced apart by a predetermined distance (e.g., 100 um) to form a gap.

[0081] A pair of outer legs (114) are formed at both ends of the opposing plate portion (112) with the middle leg (113) in between, and can be formed into a “ㄷ” shape together with the opposing plate portion. Accordingly, when the first and second cores (111, 111') are assembled in contact with each other, the core portion (110) can form an opening with a “ㅁ” shape through the center.

[0082] Referring to FIGS. 3 and 4, the “ㅁ” shaped opening may have a rounded corner (112R).

[0083] At this time, the rounded corner (112R) can contribute to improving the heat dissipation performance of the coil part (120) by increasing the contact area with the heat dissipation member (P).

[0084] For example, in the process of applying a heat dissipation member (P) to the coil portion (120) through the first through hole (132) of the bobbin (130) as shown in FIGS. 6 and 7, the heat dissipation member (P) can be brought into close contact with the extended contact surface of the rounded corner (112R), which can contribute to improving the heat dissipation performance of the coil portion (120) by maintaining a wide application area of ​​the heat dissipation member (P).

[0085] A coil section (120) may be placed between the first core (111) and the second core (111').

[0086] The coil section (120) will be described with reference to FIGS. 1 to 3.

[0087] The coil portion (120) has a wound body portion that is axially connected to the middle leg (113) of the core portion (110), and first and second terminal portions (121, 122) can be formed at each end of the wound coil.

[0088] The first and second terminal portions (121, 122) can extend parallel to each other toward the bobbin (130). The first and second terminal portions (121, 122) can be connected by passing through the second through hole (133, 134) of the bobbin (130), respectively.

[0089] The coil portion (120) includes a contact surface where at least one surface comes into contact with the heat dissipation member (P). The cross-section of the coil forming the coil portion (120) by winding may have a polygonal shape such as a square. For example, if a chamfer portion (120R) is formed so that the corner of a coil having a square cross-section has a slope or curvature, the contact surface with the heat dissipation member (P) can be enlarged.

[0090] At this time, the chamfer portion (120R) may be a straight line with only an incline or an arc shape with a curvature.

[0091] Coils adjacent to each other by winding have grooves (120H) formed by the opposing chamfered portions (120R) of both coils into which a heat dissipation member (P) is inserted. Accordingly, the area where the heat dissipation member comes into contact with the coil portion is increased, thereby improving the heat dissipation effect.

[0092] Fig. 8 is a cross-sectional view of a coil portion according to one embodiment of the present invention.

[0093] Referring to FIG. 8, the coil portion (120) may include a first conductive layer (120A) and a second conductive layer (120B) disposed on the inner side of the first conductive layer (120A).

[0094] The first conductive layer (120A) and the second conductive layer (120B) may be made of different materials. The first conductive layer (120A) may be made of copper (Cu), and the second conductive layer (120B) may be made of aluminum (Al).

[0095] In the past, it was common to construct the coil part (120) only with copper (Cu), but while copper (Cu) has the advantage of excellent conductivity, it is more expensive than aluminum (Al), so constructing the coil part (120) only with copper greatly increases the overall manufacturing cost.

[0096] According to one embodiment of the present invention, by forming the coil portion (120) with different materials for the first conductive layer (120A) and the second conductive layer (120B), a significant decrease in conductivity can be prevented while reducing costs.

[0097] For example, the first conductive layer (120A) can be formed of copper, which has relatively high conductivity, and the second conductive layer (120B) can be formed of aluminum, which has relatively low cost, so that the goals of maintaining conductivity and reducing costs can be achieved simultaneously.

[0098] The first conductive layer (120A) and the second conductive layer (120B) can be manufactured by rolling.

[0099] FIG. 9 is a graph showing the content ratio of the second conductive layer according to the change in the thickness of the first conductive layer of the coil part according to one embodiment of the present invention, and shows the area ratio and / or content ratio of copper (Cu) and aluminum (Al) per cross-sectional area of ​​the coil part when the thickness of the first conductive layer (120A) is set to six types of 0 mm, 1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm.

[0100] Referring to FIG. 9, when the thickness of the first conductive layer (120A) is 0 mm, the entire layer is formed of 100% aluminum (Al), when the thickness of the first conductive layer is 0.1 mm, it is formed of 11.7% copper (Cu) and 88.3% aluminum (Al), when the thickness of the first conductive layer is 0.2 mm, it is formed of 22.7% copper (Cu) and 77.3% aluminum (Al), and when the thickness of the first conductive layer is 0.3 mm, it can be formed of 33.1% copper (Cu) and 66.9% aluminum (Al). Also, when the thickness of the first conductive layer is 0.4 mm, it can be formed with 42.9% copper (Cu) and 57.1% aluminum (Al), and when the thickness of the first conductive layer is 0.5 mm, it can be formed with 52.0% copper (Cu) and 48.0% aluminum (Al).

[0101] That is, by setting the ratio of the thickness (T2) of the second conductive layer (120B) to the thickness (T1) of the first conductive layer (120A) to 7:3 to 9:1, the conductivity efficiency and heat generation issues can be optimized for the price.

[0102] For example, the coil portion (120) can be optimized in terms of cost-effectiveness when the thickness (T1) of the first conductive layer (120A) is formed to be 0.05 mm ≤ T1 ≤ 0.25 mm. That is, if the thickness of the first conductive layer (120A) exceeds 0.25 mm, the conductivity is excessively reduced, which reduces the power efficiency of the magnetic component or increases the heat generation problem, and if the thickness of the first conductive layer (120A) is less than 0.05 mm, the material cost reduction effect becomes minimal.

[0103] FIG. 10 is a perspective view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a first embodiment of the present invention, FIG. 11 is a cross-sectional view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a first embodiment of the present invention, FIG. 12 is a perspective view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a second embodiment of the present invention, FIG. 13 is a cross-sectional view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a second embodiment of the present invention, FIG. 14 is a perspective view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a third embodiment of the present invention, and FIG. 15 is a cross-sectional view illustrating a first and second terminal portion and a soldering cap of a coil portion according to a third embodiment of the present invention.

[0104] Referring to FIGS. 10 to 15, a coil portion (120) according to one embodiment of the present invention may include a first terminal portion (121) and a second terminal portion (122) that each penetrate the second through hole (133, 134) of the bobbin (130).

[0105] At least a portion of the lower surface of each of the first terminal portion (121) and the second terminal portion (122) can be formed to include a concave shape along the upper surface direction of the bobbin (130) from the lower surface of the bobbin (130).

[0106] The concave shape may be a groove (123) formed by processing the lower surface of the first terminal portion (121) and the second terminal portion (122) into an engraved shape.

[0107] At this time, the coil portion (120) including the first terminal portion (121) and the second terminal portion (122) may be manufactured as a double-structured rolled wire in which the first conductive layer (120A) wraps the outer surface of the second conductive layer (120B) in a tube shape.

[0108] For example, a method for manufacturing a coil portion (120) using rolled wire may be as follows: first cutting the rolled wire into a certain length and then winding it into a coil shape; or, after winding the rolled wire into a coil shape, cutting the first terminal portion (121) and the second terminal portion (122) into an appropriate length.

[0109] The coil portion (120) manufactured in this manner is stored and managed in the form of a component until the magnetic component is assembled. However, if the storage time is long, an oxide film is formed due to oxidation on the cut ends of the first terminal portion (121) and the second terminal portion (122) exposed to the air, and thus, when mounting the coil portion (120) to the PCB (200) in the future, the solder paste (S) may not adhere well, resulting in poor contact.

[0110] Therefore, it is necessary to form a soldering cap (125) by coating the first terminal portion (121) and the second terminal portion (122) of the coil portion (120) with solder paste in advance to block contact with air. At this time, the soldering paste may contain a lead component.

[0111] Solder paste containing lead components has excellent affinity with copper materials, but has poor affinity with aluminum materials, so that solder paste is coated only on the first conductive layer (120A) made of copper, and the second conductive layer (120B) made of aluminum is not properly coated and the cut surface may be exposed as it is. Therefore, as shown in FIGS. 10 to 15, by processing the lower surfaces of the first terminal portion (121) and the second terminal portion (122) into engraved groove portions (123), a soldering cap (125) that covers the cut surfaces of both the first conductive layer (120A) and the second conductive layer (120B) can be formed.

[0112] The soldering cap (125) can be formed by dipping the lower surfaces of the first terminal portion (121) and the second terminal portion (122) into a melting furnace in which solder paste is melted and then taking them out.

[0113] When the lower surfaces of the first terminal portion (121) and the second terminal portion (122) are immersed in a melting furnace in which solder paste is melted and then taken out, a solder paste coating layer can be easily formed on the surface of the first conductive layer (120A) made of copper having a high affinity for the solder paste in the first terminal portion (121) and the second terminal portion (122). In addition, when the solder paste is filled and solidified in the groove portion (123), a bridge portion (125b) is formed that connects to the surrounding solder paste coating layer formed on the first conductive layer (120A), so that the solder paste that is solidified while filling the groove portion and the entire solder paste coating layer formed on the first conductive layer (120A) are connected. As a result, a coating film that covers not only the surface of the first conductive layer but also the cut surface of the second conductive layer (120B) to block contact with air can be formed.

[0114] In this way, the solder paste that has penetrated into the home portion (123) can form a coating film in the shape of a cap that is connected to the surrounding solder paste by surface tension.

[0115] According to the present invention, by forming a groove (123) in various ways in the first terminal portion (121) and the second terminal portion (122), soldering caps (125) of various shapes can be formed on the lower surfaces of the first terminal portion (121) and the second terminal portion (122).

[0116] FIG. 10 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the first embodiment of the present invention, and FIG. 11 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the first embodiment of the present invention.

[0117] Referring to FIGS. 10 and 11, a protrusion (124) can be formed by the groove (123) so that the lower surface of the first conductive layer (120A) protrudes further than the lower surface of the second conductive layer (120B).

[0118] This protrusion (124) may be in the form of a side wall formed on the outside of the groove (123), and the solder paste melted into the groove (123) may be attached to the inner wall of this protrusion (124) to further improve the attachment strength with the terminal portion (121, 122).

[0119] To form the home portion (123), any one of grinding, drilling, cutting, or cutting methods can be used.

[0120] FIG. 12 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the second embodiment of the present invention, and FIG. 13 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the second embodiment of the present invention.

[0121] Referring to FIGS. 12 and 13, the lower surfaces of the first terminal portion (121) and the second terminal portion (122) are cut into V-grooves (123A). At this time, the V-grooves (123A) may be cut in the lateral direction of the terminal portion so as to simultaneously cut the first conductive layer (120A) and the second conductive layer (120B). More than one V-groove (123a) may be formed.

[0122] At this time, the solder paste melted into the V-groove (123a) can form a coating film in the shape of a cap that is connected to the surrounding solder paste by surface tension.

[0123] FIG. 14 is a perspective view showing the first and second terminal portions and the soldering cap of the coil portion according to the third embodiment of the present invention, and FIG. 15 is a cross-sectional view showing the first and second terminal portions and the soldering cap of the coil portion according to the third embodiment of the present invention.

[0124] Referring to FIGS. 14 and 15, a grid groove (123b) can be formed on the lower surface of the first terminal portion (121) and the second terminal portion (122). At this time, the grid groove (123b) can be formed by cutting or groove-digging processing.

[0125] According to one embodiment of the present invention, a soldering cap (125) can be formed so that the groove (123) is covered on the lower surface of the first terminal portion (121) and the second terminal portion (122). The soldering cap (125) can be formed by impregnating (immersing) or soldering so that the lower surface of the first terminal portion (121) and the second terminal portion (122) is submerged in a melting furnace in the shape of a water bath filled with molten solder paste.

[0126] As shown in FIG. 11, FIG. 13 and FIG. 15, the soldering cap (125) may include a skirt portion (125a) that forms a coating film of a certain thickness to cover the outer surface of the first conductive layer (120A) and a bridge portion (125b) that is connected to the skirt portion (125a) and is inserted into a groove portion (123) of the second conductive layer (120B) to form a coating film of a certain thickness.

[0127] At this time, the bridge portion (125b) can be formed in various shapes depending on the processing shape of the home portion (123).

[0128] At this time, by forming the length (L1) of the skirt portion (125a) of the soldering cap (125) longer than the depth (L2) of the groove portion (123) of the second conductive layer (120B), the bonding strength between the terminal portion of the coil portion and the soldering cap (125) can be improved.

[0129] Although the present invention has been described as above, those skilled in the art will recognize that the present invention can be implemented in other forms while maintaining the technical spirit and essential features of the present invention.

[0130] The scope of the present invention will be fundamentally determined by the patent claims, but it should be interpreted that not only the configuration directly derived from the description of the patent claims, but also all changes or modified forms derived from equivalent configurations are included in the scope of the present invention.

Claims

1. Bobbin; A first core and a second core are arranged facing each other on the bobbin; including a coil portion disposed between the first core and the second core, The above coil portion includes a first terminal portion and a second terminal portion that penetrate the bobbin from the upper surface of the bobbin to the lower surface, The first terminal portion and the second terminal portion each include a region concavely processed from the lower surface of the bobbin toward the upper surface on at least a portion of the lower surface, A magnetic component having a soldering cap formed on the lower surface of each of the first terminal portion and the second terminal portion, which covers the entire lower surface of the first terminal portion and the second terminal portion, including the concavely processed area.

2. In paragraph 1, The above bobbin has a first through hole in which the coil portion is mounted, A magnetic component including two second through holes spaced apart from the first through hole and through which the first terminal portion and the second terminal portion pass.

3. In paragraph 1, The coil of the above coil part is a magnetic component including a second conductive layer of a different material from the first conductive layer inside the first conductive layer.

4. In paragraph 1, The above first terminal portion and the second terminal portion are magnetic components including a protrusion in which the lower surface of the first conductive layer protrudes further than the lower surface of the second conductive layer.

5. In paragraph 1, The above soldering cap has a skirt portion that forms a coating film of a certain thickness to cover the outer surface of the first conductive layer, A magnetic component including a bridge portion connected to the above skirt portion and inserted into a groove portion of a second conductive layer to form a coating film of a certain thickness.

6. In paragraph 3, A magnetic component in which the above-mentioned concavely processed area is a groove-processed second conductive layer.

7. In paragraph 1, The above concavely processed area is a magnetic component in which the lower surface of the first terminal portion and the second terminal portion is V-grooved or grid-grooved.

8. In paragraph 5, A magnetic component in which the length of the skirt portion of the above soldering cap is formed longer than the depth of the groove portion of the second conductive layer.

9. In paragraph 1, The coil of the above coil part has a polygonal cross-section and a chamfer is formed at the corner of the polygon. A magnetic component in which at least a portion of the coil portion mounted in the first through hole forms a contact surface that contacts a heat dissipation member, and at least a portion of the contact surface is wound to form a groove into which the heat dissipation member is inserted by the mutually opposing chamfered portions of neighboring coils.

10. In paragraph 3, The thickness (T1) of the first conductive layer is 0.05 mm ≤ T1 ≤0.25 mm, A magnetic component in which the ratio of the thickness (T2) of the second conductive layer to the thickness (T1) of the first conductive layer is 70 to 90 (T2): 10 to 30 (T1).

Images