TWI679659B - Choke and inductive component and the fabrication method thereof - Google Patents

Abstract

A choke includes a magnetic core and a hollow coil. The magnetic core includes a first magnetic core body and a second magnetic core body. The first magnetic core body includes a center pillar. The second magnetic core body is a flat plate and has an opening, and one end of the center pillar is suitable for being inserted into the opening and engaging with the opening. A hollow coil is sleeved on the middle post.

Description

Choke and element with inductance and method for making element with inductance

The invention relates to a passive element, and in particular to a choke.

The function of the choke is to stabilize the current in the circuit and achieve the effect of filtering noise. The role is similar to that of a capacitor. It also stores and releases the electrical energy in the circuit to adjust the stability of the current. (Charge) to store electrical energy, and chokes are achieved in the form of magnetic fields.

FIG. 1 is a schematic top view of a conventional choke. Please refer to FIG. 1, a conventional choke 100 includes a toroidal core 110 and a wire 120 wound on the toroidal core 110. The manufacturing method of the choke 100 is as follows: First, a magnetic powder (not shown) is pressed into a ring-shaped magnetic core 110. Then, the toroidal magnetic core 110 is sintered at a temperature of 600 ° C or higher. After that, the conductive wire 120 is wound around the toroidal magnetic core 110 in a manual manner. However, the choke 100 needs to manually wind the wire 120 on the toroidal core 110 and cannot be produced in an automated manner. Therefore, the manufacturing process of the choke 100 requires a considerable labor cost.

Another type of choke is a combined choke, which uses a glue to assemble a combined magnetic core. However, during assembly, if the amount of adhesive is poorly controlled or the surface of the magnetic core assembly surface is uneven, it is easy to cause inconsistencies in the thickness of the adhesive after assembly, and the inductance of the choke will vary. High sex, which in turn leads to a decrease in yield. In order to solve the above problems, a special surface treatment procedure is proposed to enhance the assembly accuracy and increase the assembly surface of the magnetic core, but the manufacturing cost of the choke is therefore increased.

It is an object of the present invention to provide a choke which has high assembly stability and small variability in inductance value.

Another object of the present invention is to provide a choke, which uses automatic equipment to wind a wire into a hollow coil, which can effectively reduce the labor cost of the wire in the winding process.

Another object of the present invention is to provide a choke, which can control the position of the second magnetic core body relative to the first magnetic core body to match different coils to adjust the inductance, so that the chokes with different inductances can be used. Uses the same magnetic core and saves mold costs.

Another object of the present invention is to provide a choke, which can effectively reduce the appearance width of the choke and the distance between the ends of the coils when the wire groove is provided, and can reduce the pad spacing on the circuit board.

Another object of the present invention is to provide a choke, which is provided with an opening on a second magnetic core body or a bottom plate having an assembly surface, so that the center pillar protrudes toward the assembly surface, so that the protruding center pillar does not affect the choke. The appearance of the flow device.

Another object of the present invention is to provide a choke having a housing, a package, a magnetic housing, or a magnetic core with a side wall portion, which can be used to replace the magnetic glue and effectively avoid the problem of overflowing or vertical flow of the magnetic glue .

The invention provides a choke, which includes a magnetic core and a hollow coil. The magnetic core includes a first magnetic core body and a second magnetic core body. The first magnetic core body includes a center pillar. The second magnetic core body is a flat plate and has an opening, and one end of the center pillar is suitable for being inserted into the opening and engaging with the opening. A hollow coil is sleeved on the middle post.

In one embodiment of the present invention, the second magnetic core body has a joint surface and an assembly surface opposite to the joint surface. One end of the center pillar is adapted to be inserted into the opening from the joint surface, and the opening is located at the center of the second magnetic core body and communicates the joint surface and the assembly surface.

In one embodiment of the present invention, one end of the middle pillar is substantially aligned with the assembly surface.

In an embodiment of the present invention, one end of the above-mentioned middle post passes through the opening and protrudes from the assembly surface.

In one embodiment of the present invention, the hollow coil has two ends, and the two ends are disposed on an assembly surface.

In an embodiment of the present invention, the second magnetic core body further includes two lead grooves, which are located at the edges of the second magnetic core body, and the ends pass through the lead grooves.

In one embodiment of the present invention, the choke further includes a material layer. The material layer is disposed on the inner wall of the opening and between the center pillar and the opening.

In one embodiment of the present invention, the material layer is a magnetic glue.

In an embodiment of the present invention, the first magnetic core body further includes a top plate. The top plate is connected to one end of the center pillar, and the center pillar and the top plate are integrally formed. The hollow coil is located between the top plate of the first magnetic core body and the second magnetic core body.

In one embodiment of the present invention, the choke further includes a magnetic glue. Magnetic glue covers the hollow coil.

In one embodiment of the present invention, the choke further includes a magnetic glue and a casing having an open end. The shell is a barrel-shaped structure. The magnetic core and the hollow coil are disposed in the housing, and the second magnetic core body is disposed at the open end and exposes an assembly surface of the second magnetic core body. The magnetic glue is arranged in a space between the casing and the hollow coil.

In an embodiment of the present invention, the second magnetic core body further has at least one injection hole located at an edge of the second magnetic core body, and the magnetic glue is suitable for filling the casing with the injection hole.

In one embodiment of the present invention, the choke described above further includes a package, which is sleeved on the center pillar of the first magnetic core. The package includes a hollow coil and a magnetic material, and the magnetic material covers the hollow coil. around.

In one embodiment of the present invention, the choke further includes a magnetic case. The magnetic case has two open ends, an upper surface, and a lower surface opposite to the upper surface. The open ends are respectively located on the upper surface and the lower surface and communicate with each other. The hollow coil is disposed in the magnetic case and the first magnetic core body. The central post of the penetrant penetrates these open ends of the magnetic case, and the second magnetic core body is disposed on the lower surface of the magnetic case.

In one embodiment of the present invention, the first magnetic core has a top plate, and the top plate is connected to one end of the center pillar. The top plate of the first magnetic core body has a bottom portion and two side wall portions. These side wall portions are disposed on opposite sides of the bottom portion, and the extending direction of the side wall portions is substantially perpendicular to the extending direction of the bottom portion.

In one embodiment of the present invention, the second magnetic core body is disposed between the side wall portions.

In one embodiment of the present invention, the second magnetic core body is directly disposed on the hollow coil.

The invention provides a choke, which includes a magnetic core, at least one wire, and a casing. The magnetic core has a center pillar. The wire is wound on the core post. The casing is a barrel-shaped structure with an open end, wherein the magnetic core and the lead are arranged in the casing, and an open end exposes an assembly surface of the magnetic core.

In one embodiment of the present invention, the magnetic core includes a top plate and a bottom plate having an assembly surface. The center pillar is arranged between the top plate and the bottom plate, and a winding space is formed between the top plate, the bottom plate and the center pillar. The wires are located in the winding space.

In an embodiment of the present invention, the magnetic core includes a bottom plate having an assembly surface, the bottom plate has at least one injection hole located at an edge of the bottom plate, and the magnetic glue is suitable for filling the casing with the injection hole.

In an embodiment of the present invention, the above magnetic core includes a center pillar and a bottom plate with an assembly surface, wherein the bottom plate has an opening, and one end of the center pillar is suitable for being inserted into the opening and engaging the opening. The conducting wire is a hollow coil, and the hollow coil is sleeved on the pillar.

In one embodiment of the present invention, the above-mentioned bottom plate is directly disposed on the hollow coil.

The invention provides a choke, which includes a magnetic core and a package. The magnetic core includes a center pillar. The package is sleeved on the core post of the magnetic core and includes a hollow coil and a magnetic material, wherein the magnetic material covers the hollow coil.

In one embodiment of the present invention, the above-mentioned package body is made of a magnetic material to cover the hollow coil by injection molding or compression molding.

In one embodiment of the present invention, the magnetic core further includes a top plate. The center pillar and the top plate are integrally formed, and one end of the center pillar is sleeved in the package body.

In one embodiment of the present invention, the magnetic core further includes a top plate. The center pillar is integrally formed with the top plate, and one end of the center pillar passes through the package body and is substantially aligned with a surface of the package body away from the top plate.

In one embodiment of the present invention, the magnetic core further includes a top plate and a bottom plate. The top plate and the center pillar are integrally formed, and one end of the center pillar passes through the package and is substantially aligned with a surface of the package far from the top plate, and the bottom plate covers one end of the center pillar and the surface of the package.

In one embodiment of the present invention, the magnetic core further includes a top plate and a bottom plate. The top plate and the center pillar are integrally formed. The bottom plate has an opening, a joint surface and an assembly surface opposite to the joint surface. One end of the center pillar passes through the package and is inserted into the opening from the joint surface, and one end of the center pillar is substantially aligned with the assembly surface.

The invention provides a choke, which includes a magnetic core and a hollow coil. The magnetic core includes a first magnetic core body and a second magnetic core body. The first magnetic core body includes a top plate and a center pillar. The top plate has a bottom portion and a side wall portion. The side wall portion is arranged around the periphery of the bottom portion, and the extending direction of the side wall portion is substantially perpendicular to the extending direction of the bottom portion, and the side wall portion surrounds the center pillar. The second magnetic core body is a flat plate and has an opening, and one end of the center pillar is suitable for being inserted into the opening. The hollow coil is sleeved on the center pillar and is located between the top plate of the first magnetic core body and the second magnetic core body. The height of the hollow coil is less than the height of the side wall portion of the top plate. The side wall portion is in contact with at least part of the hollow coil. .

In one embodiment of the present invention, the middle pillar and the top plate are integrally formed.

In an embodiment of the present invention, the second magnetic core body has a joint surface and an assembly surface opposite to the joint surface, and one end of the center pillar is adapted to be inserted into the opening from the joint surface, and the opening is located in the second The center of the magnetic core body connects the joint surface and the assembly surface.

In one embodiment of the present invention, one end of the middle pillar is substantially aligned with the assembly surface.

In an embodiment of the present invention, one end of the above-mentioned middle post passes through the opening and protrudes from the assembly surface.

In an embodiment of the present invention, the first magnetic core body further includes at least one wire groove. The lead groove is disposed on a side wall portion of the top plate.

In one embodiment of the present invention, the choke further includes a material layer. The material layer is disposed on the inner wall of the opening and is located between the center pillar and the opening.

In one embodiment of the present invention, the second magnetic core body is directly disposed on the hollow coil.

Based on the above, since the choke of the present invention uses an automatic device to wind the wire into a hollow coil, the hollow coil is sleeved on the center pillar of the first magnetic core, and one end of the center pillar is placed in the first Inside the openings of the two magnetic core bodies, the hollow coil is located between the top plate of the first magnetic core body and the second magnetic core body at this time to complete its assembly. Compared with the conventional technology, the choke of the present invention can not only effectively reduce the labor cost of the wires in the winding process, but also improve the assembly stability and reduce the variability of the inductance value.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are described below in detail with reference to the accompanying drawings.

100, 300a, 300c ~ 300f, 400a ~ 400c, 500a ~ 500e, 600a, 600b, 700a‧‧‧ choke

110‧‧‧ Toroidal Core

120, 420‧‧‧ wires

310, 310 ’, 410a ~ 410c, 510a ~ 510d, 610‧‧‧ core

311, 311 ’, 611, 611’, 711a‧‧‧ the first magnetic core

312, 414, 414 ’, 414”, 512a ~ 512e, 614, 614 ’, 714a‧‧‧

312a, 312b, 513b ~ 513e, 614a, 614a’‧‧‧

314, 314 ’, 412, 412’, 514b ~ 514e, 612, 612’‧‧‧

314a, 612a, 612a’‧‧‧ bottom

314b, 612b, 612b ’, 712a‧‧‧ sidewall

315, 315 ’, 617, 617’, 717a‧‧‧ second core

315a, 416a, 518a, 617a

315b, 416b, 518b, 617b‧‧‧Assembly surface

316, 517, 619‧‧‧ opening

317a, 317b, 616‧‧‧ wire duct

318, 416c‧‧‧ injection hole

320, 522, 620‧‧‧ hollow coil

322, 324‧‧‧

323‧‧‧winding department

330‧‧‧material layer

340, 440‧‧‧ Magnetic Adhesive

350, 430‧‧‧shell

352, 432‧‧‧ open end

360‧‧‧Magnetic case

360a‧‧‧ Top surface

360b‧‧‧ lower surface

362a, 362b‧‧‧ open end

416, 416 ’, 416”, 516d, 516e‧‧‧ floor

370, 520‧‧‧ package

520a‧‧‧ surface

524‧‧‧ Magnetic Materials

526‧‧‧perforation

S‧‧‧winding space

FIG. 1 is a schematic top view of a conventional choke.

FIG. 2A is a schematic diagram of a choke according to an embodiment of the present invention.

FIG. 2B is an exploded view of the choke of FIG. 2A.

FIG. 2C is a schematic bottom view of the choke of FIG. 2A.

FIG. 3 is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

FIG. 4 is a schematic perspective view of a choke according to another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

FIG. 6A is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

FIG. 6B is a schematic perspective view of the magnetic casing of FIG. 6A.

FIG. 7 is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

8A is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

FIG. 8B is an exploded view of the choke of FIG. 8A.

FIG. 8C is a schematic perspective view of the choke of FIG. 8A.

FIG. 8D is another exploded view of the choke of FIG. 8A.

FIG. 8E is another exploded view of the choke of FIG. 8A.

FIG. 9 is a schematic cross-sectional view of a choke according to another embodiment of the present invention.

10A to 10D are schematic cross-sectional views of four modified structures of the magnetic core of FIG. 9.

FIG. 11A is a schematic diagram of a choke according to another embodiment of the present invention.

FIG. 11B is an exploded view of the choke of FIG. 11A.

FIG. 11C is a schematic diagram of a choke according to another embodiment of the present invention.

FIG. 11D is a schematic diagram of a choke according to another embodiment of the present invention.

Fig. 12 is a schematic diagram of a magnetic circuit of a choke.

FIG. 2A is a schematic view of a choke according to an embodiment of the present invention, FIG. 2B is an exploded view of the choke of FIG. 2A, and FIG. 2C is a bottom view of the choke of FIG. 2A. Please refer to FIG. 2A and FIG. 2B at the same time. In this embodiment, the choke 300a includes a magnetic core 310 and a hollow coil 320, wherein the magnetic core 310 includes a first magnetic core body 311 and a second magnetic core body 315.

The first magnetic core body 311 includes a center pillar 312 and a top plate 314. One end 312b of the center pillar 312 is connected to the top plate 314 to form a T-shaped structure. The center pillar 312 and the top plate 314 are integrally formed. The second magnetic core body 315 is a flat plate, and has a joint surface 315a, an assembly surface 315b opposite to the joint surface 315a, an opening 316, and two opposite sides of the opening 316 and located on the second magnetic core body 315. The lead grooves 317a, 317b. The opening 316 is located at the center of the second magnetic core body 315 and communicates the joint surface 315a and the assembly surface 315b. One end 312a of the pillar 312 in the first magnetic core body 311 is adapted to be inserted into the opening 316 from the joint surface 315a and communicate with the opening 316 joints. The joining manner of the one end 312a of the center pillar 312 and the opening 316 may be a tight fit bonding or an adhesive bonding. In this embodiment, the cross-sectional shapes of the top plate 314, the second magnetic core body 315, and the opening 316 are all circular, and the center pillar 312 is a cylinder, but not limited thereto. For example, the top plate 314, the second The shape of the magnetic core body 315 and the opening 316 may also be rectangular, and the center pillar 312 is a rectangular pillar.

The material of the magnetic core 310 is a ferrite material, iron, or a low magnetic loss material. Ferrite materials include nickel-zinc ferrite (Ni-Zn ferrite) or manganese-zinc ferrite (Mn-Zn ferrite). The low magnetic loss material is, for example, an iron-containing alloy, and the iron-containing alloy may be an iron-silicon aluminum alloy, an iron-nickel molybdenum alloy, an iron-nickel alloy, or an amorphous (Amorous) alloy. It is worth noting that low magnetic loss materials are used as The magnetic core 310 can improve magnetic permeability and achieve low iron loss. In this embodiment, the first core body 311 and the second core body 315 of the magnetic core 310 are made of ferrite. The magnetic permeability of the magnetic core 310 is, for example, 75 or more. In detail, the magnetic core 310 is A ferrite powder (ferrite powder) is used to mix a binder, which is formed by pressure molding and firing. The binder includes polymethylallyl (PMA) Synthesize resin.

It must be noted here that during the manufacturing process of the first magnetic core body 311 and the second magnetic core body 315, a gap is easily generated at the joint of the center pillar 312 and the opening 316 due to the influence of process tolerances. Please refer to the figure 2C, which means that the diameter of the opening 316 is larger than the diameter of the center pillar 312. Therefore, in this embodiment, a material layer 330 can be selectively coated on the inner wall of the opening 316, which means that the material layer 330 is located between the center pillar 312 and the opening 316, so as to reduce the center pillar 312 and the opening 316 during assembly. The effect of the spacing between the two values on the sense value to improve the stability of the assembly and reduce the variability of the sense value. The material layer 330 is, for example, a resin colloid or a magnetic colloid. It is worth noting that the material layer 330 can be directly used as an adhesive when one end 312a of the center pillar 312 and the opening 316 are adhesively bonded.

The hollow coil 320 is sleeved on the center post 312 of the first magnetic core body 311 and is located between the top plate 314 of the first magnetic core body 311 and the joint surface 315 a of the second magnetic core body 315. In detail, in this embodiment, the conductive wire is wound into a hollow coil 320 by using an automated device. The conductive wire is, for example, a round wire (the minimum cross-sectional area is circular) or a flat wire (the minimum cross-sectional area is rectangular). The copper wire is covered with an enameled layer, and the enameled layer is an insulating layer. Specifically, the hollow coil 320 has two end portions 322 and 324 and a winding portion 323 located between the two end portions 322 and 324. The winding portion 323 is wound around the center pillar 312 of the first magnetic core body 311, and two The end portions 322 and 324 pass through the lead grooves 317 a and 317 b of the second magnetic core body 315 and are disposed on the assembly surface 315 b. Both ends 322, 324 of the hollow coil 320 can be directly used as external electrodes or connected A lead frame is used as an external electrode, and the external electrode can be electrically connected to an external circuit in a through-hole mount method or a surface mount method.

It is worth mentioning that the second magnetic core body 315 is directly pressed onto the hollow coil 320, so that the second magnetic core body 315 is directly disposed on the hollow coil 320. Therefore, the second magnetic core body 315 can be positioned by the height of the hollow coil 320 The magnetic core body 315 position. While one end 312a of the pillar 312 in the first magnetic core body 311 in this embodiment is substantially aligned with the assembly surface 315b of the second magnetic core body 315, but in other embodiments, please refer to FIG. 3, the first magnetic core One end 312a of the pillar 312 in the body 311 passes through the opening 316 of the second magnetic core body 315 and protrudes from the assembly surface 315b, which still belongs to the technical solution of the present invention and does not depart from the scope of the present invention. In FIG. 3, the height of the center pillar 312 protruding from the assembly surface 315b is lower than the length of the two ends 322, 324 of the hollow coil 320 extending beyond the wire grooves 317a, 317b to prevent the center pillar 312 from affecting the ends 322, 324 and Electrical connection of external circuit.

In addition, the choke 300a of this embodiment can selectively fill a magnetic glue 340 between the first magnetic core body 311 and the second magnetic core body 315 and cover the winding portion 323 and a part of the hollow coil 320. The end portions 322 and 324 are used to electrically connect the uncovered end portions 322 and 324 to an external circuit. The magnetic glue 340 includes a resin material and a magnetic powder material, wherein the magnetic powder material accounts for more than 70% of the total weight of the magnetic glue 340, and the magnetic permeability of the magnetic glue 340 is, for example, 6 or more, but is not limited thereto. The resin material may be selected from Polyamide 6, PA6, Polyamide 12, PA12, Polyphenylene Sulfide (PPS), Polybutyleneterephthalate (PBT) ) Or ethylene-ethyl acrylate copolymer (EEA). The magnetic powder material may be a metal soft magnetic material or a ferrite powder, wherein the metal soft magnetic material may be selected from iron powder, FeAlSi Alloy, FeCrSi Alloy, or stainless steel. one of them.

Since the choke 300a of this embodiment uses an automatic device to wind the wire into a hollow coil 320, the hollow coil 320 is set on the center post 312 of the first magnetic core body 311, and then one end of the center post 312 312a is placed in the opening 316 of the second magnetic core body 315 to complete the assembly. Compared with the conventional choke 100, the choke 300a of this embodiment can effectively reduce the labor cost of the wire during the winding process.

In addition, the present invention may use different hollow coils to control the position of the second magnetic core body 315 relative to the first magnetic core body 311 to adjust the inductance, so that chokes of different inductances can use the same magnetic core, and Save mold costs. Furthermore, the opening 316 is provided on the second magnetic core body 315 having the assembly surface 315b, so that when the position of the second magnetic core body 315 is used to adjust the sensing value, the center pillar 312 can protrude toward the assembly surface 315b, so that the protruding The center pillar 312 does not affect the appearance of the choke 300a. In addition, since the second magnetic core body 315 has lead grooves 317a and 317b through which both ends 322 and 324 of the hollow coil 320 can pass, the distance between the ends 322 and 324 and the width of the appearance of the choke 300a can be reduced. And when the two end portions 322 and 324 are used as external electrodes, the distance from the pads of the circuit board can be effectively reduced.

FIG. 4 is a schematic perspective view of a choke according to another embodiment of the present invention. Please refer to FIG. 2A and FIG. 4 at the same time. The choke 300c of FIG. 4 is similar to the choke 300a of FIG. 2A. The difference is that the choke 300c of FIG. 4 further includes a housing having an open end 352. 350, and the second magnetic core body 315 'further has at least one injection hole 318 (only two are schematically shown in FIG. 4) located at the edge of the second magnetic core body 315', wherein the casing 350 is a barrel structure, The magnetic core 310 'and the hollow coil 320 are disposed in the housing 350, and the second magnetic core body 315' is disposed at the open end 352, and the open end 352 exposes the assembly surface 315b of the second magnetic core body 315 ', and the magnetic glue 340 is suitable to be filled in the housing 350 through the injection hole 318 to be disposed in the space between the housing 350 and the hollow coil 320, and to cover the hollow coil 320, the center pillar 312 and the top plate 314 of the first magnetic core body 311, and Part of the second magnetic core body 315 '.

Because the choke 300c of this embodiment has a housing 350, there is no problem of overflow or vertical flow when the magnetic glue 340 is filled (especially the higher the height of the choke 300c, such as 10 cm (mm) or more ), The appearance of the choke 300c is also more beautiful, and can shield the crack of the magnetic glue 340 (the surface of the choke is cracked due to the different thermal expansion coefficient of the resin material and the copper wire) and prevent rust. In addition, when the material of the case 350 is a metal or a magnetic material, the choke 300c also has an effect of preventing electromagnetic interference. When the material of the casing 350 is metal, heat can be provided to reduce the overall temperature of the choke 300c, thereby improving efficiency.

FIG. 5 is a schematic cross-sectional view of a choke according to another embodiment of the present invention. Please refer to FIG. 2A and FIG. 5 at the same time. The choke 300d of FIG. 5 is similar to the choke 300a of FIG. 2A. The difference is that the choke 300d of FIG. 5 is manufactured by injection molding. The magnetic glue 340 is wrapped around the hollow coil 320 to form a package 370 by press molding or press molding. Then, the package 370 is set on the center pillar 312 to make the first magnetic core 311 One end 312a of the center pillar 312 passes through the hollow coil 320 and the second magnetic core body 315 and is aligned with the assembly surface 315b of the second magnetic core body 315 to complete the assembly of the choke 300d. Because the choke 300d of this embodiment is manufactured by first covering the hollow coil 320 with the magnetic glue 340 to form a package 370, and then assembling the magnetic core 310, problems of overflowing or vertical flow can be avoided. In addition, the magnetic glue is formed through injection molding and compression molding, so that the density of the magnetic glue in the package 370 can be increased and the magnetic permeability can be improved. Therefore, under the condition of achieving the same inductance value, the choke 300d can be compared with the chokes 300a and 300c. Has a smaller volume.

FIG. 6A is a schematic cross-sectional view of a choke according to another embodiment of the present invention, and FIG. 6B is a schematic perspective view of the magnetic case of FIG. 6A. Please refer to FIG. 2A, FIG. 6A and FIG. 6B at the same time. The choke 300e of FIG. 6A is similar to the choke 300a of FIG. 2A. The difference is that the choke 300e of FIG. 6A is provided by a magnetic housing 360. Instead of the magnetic glue 340 of FIG. 2A, the magnetic casing 360 has an upper surface 360a, a With respect to the lower surface 360b and the two open ends 362a and 362b of the upper surface 360a, the open ends 362a and 362b are located on the upper surface 360a and the lower surface 360b, respectively, and the open ends 362a and 362b communicate with each other. In detail, the hollow coil 320 is disposed in the magnetic case 360, and the center post 312 of the first magnetic core body 311 penetrates these open ends 362a and 362b of the magnetic case 360, so that the top plate 314 of the first magnetic core body 311 bears. Abutting on the upper surface 360a of the magnetic case 360, and the second magnetic core body 315 is disposed on the lower surface 360b of the magnetic case 360. Since the choke 300e of this embodiment replaces the magnetic glue 340 by the magnetic case 360, there is no problem of overflowing glue or vertical flow.

FIG. 7 is a schematic cross-sectional view of a choke according to another embodiment of the present invention. Please refer to FIG. 2A and FIG. 7 at the same time. The choke 300f of FIG. 7 is similar to the choke 300a of FIG. 2A, except that the top plate 314 of the first magnetic core body 311 'of the choke 300f of FIG. It has a bottom portion 314a and two side wall portions 314b, wherein the side wall portions 314b are disposed on opposite sides of the bottom portion 314a, and the extending direction of the side wall portions 314b is substantially perpendicular to the extending direction of the bottom portion 314a. The extending direction of the side wall portions 314b is parallel to the extending direction of the center pillar 312. The height of the side wall portion 314b may be the same as the height of the center pillar 312, and the second magnetic core body 315 is disposed between the side wall portions 314b. The magnetic glue 340 is filled between the side wall portions 314b of the first magnetic core body 311, and covers the winding portion 323 and a portion of an end portion (not shown) of the hollow coil 320. Since the choke 300f of this embodiment is provided with the side wall portion 314b, the problem of overflow or vertical flow of the magnetic glue 340 can be improved.

8A is a schematic cross-sectional view of a choke according to another embodiment of the present invention, FIG. 8B is an exploded schematic view of the choke of FIG. 8A, and FIG. 8C is a perspective schematic view of the choke of FIG. 8A. It must be noted here that, for convenience of description, FIG. 8B omits the illustration of the magnetic glue 340. Please refer to FIG. 8A, FIG. 8B and FIG. 8C at the same time. In this embodiment, the choke 400a includes a magnetic core 410a, at least one wire 420, and a casing 430. In detail, the magnetic core 410a includes a top plate 412, a center pillar 414, and a bottom plate 416. The plate 416 has a joint surface 416a, an assembly surface 416b opposite to the joint surface 416a, and at least one injection hole 416c (two are shown schematically in FIG. 8C), wherein the center pillar 414 is disposed between the top plate 412 and the bottom plate 416, and A winding space S is formed between the top plate 412, the center pillar 414, and the bottom plate 416. The material and manufacturing method of the magnetic core 410a are the same as those of the magnetic core 310, so they are not repeated here. In this embodiment, the top plate 412, the center pillar 414, and the bottom plate 416 of the magnetic core 410a are integrally formed and constitute a drum-core structure.

The conductive wire 420 is wound on the center pillar 414 and is located in the winding space S. The conductive wire 420 may be, for example, a round wire (the minimum cross-sectional area is circular) or a flat wire (the minimum cross-sectional area is rectangular). The wire is covered by an enamelled layer, which is an insulating layer. In addition, the conducting wire 420 may have a first plurality of winding coils located at the innermost layer and a second plurality of winding coils located at the outermost layer. The conducting wire 420 may have two linear end portions 420a, 420b, of which two linear end portions 420a 420b is respectively connected to the bottom multiple cores of the first plurality of winding coils and the second plurality of winding coils, which are disposed below the lower surface and are respectively connected to the bottommost winding coil of the first plurality of winding coils and the The lowermost windings of the second plurality of windings are in contact with each other. The two linear end portions 420a, 420b extend from above the magnetic core body 410a to below the bottom surface of the magnetic core body 410a, respectively. The two pins of the component are connected to an external circuit. In addition, the wires 420 can be wound on the center pillar 414 of the magnetic core 410a by using an automated device, and the number of the wires 420 is not limited in this embodiment, which means that the wires 420 can be one or more.

The housing 430 is a barrel-shaped structure having an open end 432. The magnetic core 410a and the lead wires 420 are disposed in the housing 430, and the open end 432 exposes the assembly surface 416b of the bottom plate 416 of the magnetic core 410a.

In addition, the choke 400a of this embodiment further includes a magnetic glue 440, wherein the magnetic glue 440 is adapted to be filled in the housing 430 through the injection hole 416c to fill the winding space S and cover the wire 420 and a part of the magnetic Core 410a. The material of the magnetic glue 440 is the same as that of the magnetic glue 340, so it will not be repeated here.

Since the choke 400a of this embodiment has a housing 430, there is no problem of overflow or vertical flow when the magnetic glue 430 is filled, and the appearance of the choke 400a is also beautiful and can shield the crack of the magnetic glue And prevent rust. In addition, if the material of the housing 430 is a metal or a magnetic material, the choke 400 a can have an effect of preventing electromagnetic interference. If the material of the casing 430 is metal, heat can be provided to reduce the overall temperature of the choke 400a, thereby improving efficiency.

It is worth mentioning that the present invention does not limit the shape of the magnetic core 410a. In other embodiments, please refer to FIG. 8D. The magnetic core 410b of the choke 400b may also include a top plate 412 ', a center pillar 414', and a The bottom plate 416 'is composed of the center pillar 414' and the top plate 412 ', and the bottom plate 416' is connected to one end of the center pillar 414 'by an adhesive method, or the center pillar 414', the top plate 412 'and the bottom plate 416' are all used. The wires are connected in an adhesive manner, and the wire 420 is a hollow coil and is sleeved on the center pillar 414 '. Please refer to FIG. 8E. The magnetic core 410c of the choke 400c may also be composed of a center pillar 414 "and a bottom plate 416", wherein the wire 420 is a hollow coil and is sleeved on the center pillar 414 ", which still belongs to the present invention. The technical solutions that can be adopted in the invention do not depart from the scope of the present invention.

FIG. 9 is a schematic cross-sectional view of a choke according to another embodiment of the present invention. Please refer to FIG. 9. In this embodiment, the choke 500 a includes a magnetic core 510 a and a package 520, wherein the magnetic core 510 a includes a center pillar 512 a, and the package 520 is sleeved on the center pillar 512 a of the magnetic core 510 a. The package 520 includes a hollow coil 522 and a magnetic material 524 covering the hollow coil 522. The package body 520 is formed by injecting molding or press molding by covering the hollow coil 522 with a magnetic material 524, and the package body 520 has a perforation 526 for providing a magnetic core 510a. Center pillar 512a. In this embodiment, the height of the package 520 is equal to the length of the center pillar 512b, so that both ends of the center pillar 512b are aligned with the surface of the package 520. The material of the magnetic core 510a is the same as that of the magnetic core 310, and the hollow coil 522 is the same as the hollow coil 320, and the material of the magnetic material 524 is the same as that of the magnetic glue 340, so it is not repeated here.

In the manufacture of the choke 500a of this embodiment, a package 520 is first formed, and then the central post 512a of the magnetic core 510a is passed through the hollow coil 522 to form the choke 500a. However, the effect achieved by the choke 500a of this embodiment is the same as that of the choke 300d, so it will not be repeated here.

The structure of the magnetic core 510 a is not limited to the structure disclosed in FIG. 9, and the magnetic core 510 a may also be the structure disclosed in FIGS. 10A to 10D. In detail, as shown in FIG. 10A, the magnetic core 510b of the choke 500b further includes a top plate 514b, wherein the center pillar 512b and the top plate 514b are integrally formed, and one end 513b of the center pillar 512b is sleeved in the package 520. That is, one end 513b of the center pillar 512b is not exposed outside the package 520, and the height of the package 520 is greater than the length of the center pillar 512b. As shown in FIG. 10B, the magnetic core 510c of the choke 500c further includes a top plate 514c, wherein the center pillar 512c and the top plate 514c are integrally formed, and one end 513c of the center pillar 512c passes through the package 520 and is separated from the package 520 away from the top plate. A surface 520a of 514c is substantially aligned. As shown in FIG. 10C, the magnetic core 510d of the choke 500d further includes a top plate 514d and a bottom plate 516d. The top plate 514d and the center pillar 512d are integrally formed, and one end 513d of the center pillar 512d passes through the package body 520 and is packaged with the package. A surface 520a of the body 520 away from the top plate 514d is substantially aligned, and a bottom plate 516d covers one end 513d of the center pillar 512d and the surface 520a of the package 520. As shown in FIG. 10D, the magnetic core 510e of the choke 500e further includes a top plate 514e and a bottom plate 516e. The top plate 514e and the center pillar 512e are integrally formed, and the bottom plate 516e has an opening 517, a joint surface 518a and an opposite surface. Assembly surface 518b on the joint surface 518a. One end 513e of the center pillar 512e passes through the package 520 and is inserted into the opening 517 from the joint surface 518a, and one end 513e of the center pillar 512e is substantially aligned with the assembly surface 518b.

FIG. 11A is a schematic diagram of a choke according to another embodiment of the present invention, and FIG. 11B is an exploded schematic diagram of the choke of FIG. 11A. Please refer to FIG. 11A and FIG. 11B together. In this embodiment, the choke 600a It includes a magnetic core 610 and a hollow coil 620. In detail, the magnetic core 610 includes a first magnetic core body 611 and a second magnetic core body 617. The first magnetic core body 611 includes a top plate 612, a center pillar 614, and at least one wire groove 616 (two are schematically shown in FIG. 11A), wherein the center pillar 614 and the top plate 612 are integrally formed, and the top plate 612 has a bottom 612a and a side wall portion 612b disposed around the bottom portion 612a. The side wall portion 612b surrounds the center pillar 614. The diameter of the center pillar 614 is smaller than the length of one side of the bottom portion 612a of the top plate 612, and the extending direction of the side wall portion 612b is substantially perpendicular to the extending direction of the bottom portion 612a. The extending direction of the side wall portion 612b is parallel to the extending direction of the center pillar 614. The lead groove 616 is disposed on the side wall portion 612 b of the top plate 612, and the width of the lead groove 616 can be designed according to the wire diameter of the hollow coil 620.

The second magnetic core body 617 is a flat plate and has a joint surface 617a, an assembly surface 617b opposite to the joint surface 617a, and an opening 619. The opening 619 is located at the center of the second magnetic core body 617 and communicates the joint surface 617a and the assembly surface 617b. One end 614a of the center pillar 614 is adapted to be inserted into the opening 619 from the joint surface 617a. In particular, the height of the side wall portion 612b of the top plate 612 may be the same as the height of the center pillar 614, and the second magnetic core body 617 is disposed between the side wall portions 612b. The material of the magnetic core 610 in this embodiment is the same as that of the magnetic core 310, so it will not be repeated here. In this embodiment, the center pillar 614 is, for example, a cylinder, and the shape of the second magnetic core body 617, the opening 619, and the bottom 612a of the top plate 612 is, for example, a circle, and the diameter of the opening 619 is greater than or equal to that of the center pillar 617. diameter.

The hollow coil 620 is sleeved on the center pillar 614 and is located between the top plate 612 of the first magnetic core body 611 and the second magnetic core body 617. The height of the hollow coil 620 is smaller than the height of the side wall portion 612b of the top plate 612, and the side wall The portion 612b is in contact with at least a part of the hollow coil 620. The manufacturing method, material, and structure of the hollow coil 620 are the same as those of the hollow coil 320, so they will not be repeated here.

It is worth mentioning that the second magnetic core body 617 in this embodiment is directly pressed on the hollow coil 620, so that the second magnetic core body 617 is directly disposed on the hollow coil 620, so the hollow coil 620 can be used. Position of the second magnetic core body 617 in this embodiment. In this embodiment, one end 614a of the pillar 614 in the first magnetic core body 611 is substantially aligned with the assembly surface 617b of the second magnetic core body 617, but in other places In the embodiment, one end 614a of the pillar 614 in the first magnetic core body 611 can pass through the opening 619 of the second magnetic core body 617 and protrude from the assembly surface 617b. The height of the central pillar 614 protruding from the assembly surface 617b is lower than the hollow coil. The length of the two ends of 620 extending outside the wire groove 616 still belongs to the technical solution that can be adopted in the present invention, without departing from the scope of the present invention.

In addition, in this embodiment, a material layer 630 may be selectively applied at the junction between the center pillar 614 and the opening 619 to reduce the influence of the distance between the center pillar 614 and the opening 619 on the sensing value during assembly. The material layer 630 is, for example, a resin colloid or a magnetic colloid. Of course, in the preferred embodiment, the diameter of the post 614 in the first magnetic core body 611 is equal to the diameter of the opening 619 of the second magnetic core body 617.

In addition, the present invention does not limit the shapes of the first magnetic core body 611 and the second magnetic core body 617, although the bottom 612a of the top plate 612 of the first magnetic core body 611 mentioned here is circular, and the second The shape of the magnetic core body 617 is circular, but in other embodiments, please refer to FIG. 11C. The bottom portion 612a 'of the top plate 612' of the first magnetic core body 611 'may also be rectangular, and the side wall portion 612b' surrounds the bottom portion 612a. It is arranged around a rectangular shape, and the second magnetic core body 617 'is disposed in the side wall portion 612b' and has a circular shape, which still belongs to the technical solution of the present invention and does not depart from the scope of the present invention.

In the choke 600a of this embodiment, the wire is wound into a hollow coil 620 by using an automatic device, and then the hollow wire 620 is looped on the center pillar 614 of the first magnetic core 611, and one end 614a of the center pillar 614 is set. It is placed in the opening 619 of the second magnetic core body 617, and the hollow coil 620 is located between the top plate 612 of the first magnetic core body 611 and the second magnetic core body 617, and the assembly is completed. Compared with the conventional technology, the choke 600a of this embodiment can effectively reduce the labor cost of the wire in the winding process. A selective coating material layer 630 may be provided at the junction between the center pillar 614 and the opening 619 to improve assembly stability and reduce inductance variability.

Since the choke 600a of this embodiment uses the side wall portion 612b of the top plate 612 to cover the periphery of the hollow coil 620 to replace the magnetic glue, in addition to the problem of overflowing glue or vertical flow, the process steps can be reduced and further Reduce manufacturing costs. In addition, different hollow coils can be used to control the position of the second magnetic core body 617 relative to the first magnetic core body 611 to adjust the inductance, so that chokes of different inductances can use the same magnetic core, thereby saving the mold. cost. Furthermore, the opening 619 is provided on the second magnetic core body 617 having the assembly surface 617b, and when the position of the second magnetic core body 617 is used to adjust the sensing value, the center pillar 614 can protrude toward the assembly surface 617b, so that the protruding The center pillar 617 does not affect the appearance of the choke 600a.

In addition, FIG. 11D is a schematic cross-sectional view of a choke according to another embodiment of the present invention. Please refer to FIG. 11A and FIG. 11D. The choke 600b of FIG. 11D is similar to the choke 600a of FIG. 11A. The difference is that the first core body of the magnetic core 610 'of the choke 600b of FIG. 11D The height of the side wall portion 612b 'of 611' is lower than the height of the center pillar 614 '. One end 614a' of the center pillar 614 'is adapted to be inserted into the opening 619 from the joint surface 617a of the second magnetic core body 617 and the second magnetic core. Both ends of the body 617 are disposed on the side wall portion 612b ', that is, the second magnetic core body 617 can be positioned by the side wall portion 612b'. In this embodiment, the side wall portion 612b 'is also used instead of the magnetic glue, so in addition to the problem of overflowing or vertical flow, the number of manufacturing steps can be reduced and the manufacturing cost can be reduced.

The measured results will be presented below to compare the conventional choke 100 of FIG. 1 with some of the chokes 300a, 300c, 300d, 600a, and 600b of this embodiment.

[First set of measured results]

This actual measurement compares the conventional choke 100 with the same material and similar volume of the magnetic core and the choke 300a of FIG. 2A in this embodiment. Table 1 is the choke 100 and three chokes obtained from the power supply output 12 volts to 5 volts. Experimental data of the same choke 300a. Table 2 shows the experimental data of choke 100 and three identical chokes 300a obtained from the power supply outputting 12 volts to 3.3 volts.

According to Table 1 and Table 2, it can be known that the efficiency of the choke 300a is higher than that of the conventional choke 100 under the same current of the choke 100 and the choke 300a. In other words, the design of the magnetic core 310 of the choke 300a is better than that of the conventional choke 100.

[Second set of measured results]

This actual measurement compares the conventional choke 100 with the same material and similar volume of the magnetic core and the choke 300c of FIG. 4 in this embodiment. Table 3 shows the experimental data of the choke 100 and the four identical chokes 300c obtained from the power supply outputting 12 volts to 5 volts. Table 4 shows the choke 100 and the choke 100 obtained from the power supply outputting 12 volts to 3.3 volts. Experimental data for four identical chokes 300c.

Table three

According to Tables 3 and 4, it can be known that at the same current of the choke 100 and the choke 300c, the efficiency of the choke 300c at light load (50% load) is higher than that of the conventional choke 100.

[The third group of measured results]

This actual measurement compares the conventional choke 100 with the same material and similar volume of the magnetic core and the choke 300d of FIG. 5 in this embodiment. Table 5 shows the experimental data of the choke 200 and the choke 300d obtained from the power supply outputting 12 volts to 3.3 volts.

According to Table 5, under the same current of the choke 100 and the choke 300d, the efficiency of the choke 300d at light load is higher than that of the conventional choke 100.

[The fourth group of measured results]

The actual measurement is to perform an experiment on the influence of the unilateral distance between the junction of the center pillar 312 and the opening 316 on the initial inductance of the choke 300a. The thickness of the second magnetic core 315 is 2.5 cm (mm). Table 6 shows the experimental data of the initial inductance of the choke 300a with one-sided pitch.

According to Table 6, it can be seen that when the unilateral distance is 0.1 cm (mm), the initial sensitivity decreases by 6.91%; when the unilateral distance is larger (for example, 0.4 cm (mm)), the initial sensitivity decreases (17.51%). ). That is to say, during the manufacturing process of the choke 300a, the pitch generated at the junction of the center pillar 312 and the opening 316 will affect the variability of the sensing value.

In the following, experiments will be performed on the initial inductance of the choke 310a by the filling material layer 340 at the junction of the center pillar 312 and the opening 316. The thickness of the second magnetic core body 315 is 2.5 centimeters (mm). Table 7 shows the experimental data of the thickness of the material layer on the initial sensitivity.

According to Table 7, it can be seen that when the thickness of the magnetic material layer 330 is increased from 0.1 cm (mm) to 0.4 cm (mm), the change in the amount of inductance is still less than 5%, that is, compared to FIG. 18, the material layer 330 The effect of the thickness on the initial sensitivity is smaller than the effect of the spacing generated at the junction of the center pillar 312 and the opening 316 on the initial sensitivity. In other words, the variability of the sensed value due to the process tolerance can be reduced by selectively filling the material layer 330.

In the following, experiments are performed with the thickness of the second magnetic core 315 being 3 centimeters (mm). Table 8 shows the experimental data of the thickness of the material layer on the initial sensing amount.

According to Table 8 and Comparison Table 7, it can be known that when the second magnetic core body 315 is increased from 2.5 cm (mm) to 3 cm (mm), the amount of change in inductance is only 0.81% higher than that when 2.5 cm (mm), and the material layer When the thickness of the 330 is 0.4 centimeters (mm), the influence of the sensitivity is still less than 5%, that is, the coating material layer 330 at the joint of the center pillar 312 and the opening 316 has a greater impact on the sensitivity than increasing the thickness of the second magnetic core 315 Good effect.

[Fifth set of measured results]

This actual measurement is to simulate the influence of the presence or absence of the wire slot 616 of the choke 600a of FIG. 11A on the inductance. The hollow coil 620 has a wire diameter of 1 cm (mm), a coil of 5.5 turns, and a DC impedance of 0.5 ohm (mΩ). It can be known from the simulation results that when the choke 600a has no wire groove 616, the inductance is about 3.3 microhenry (μH); When the choke 600a has a wire groove 616, the inductance is about 3.43 microhenry (μH), that is, with or without the wire groove 616, the difference in inductance is 4%.

Next, an experiment is performed on the influence of the width of the wire groove 616 on the inductance. The material of the first magnetic core body 611 of the choke 600a is an iron-silicon aluminum alloy, and its magnetic permeability is 125. Table 9 shows the experimental data of the distance between the wire grooves and the inductance.

According to Table 9, it can be known that the pitch of the wire groove 616 is from 1.6 mm to 4.8 mm, and the decrease rate of the inductance of the choke 600a is less than 3%. It can be seen that the arrangement of the wire groove 616 has a small influence on the amount of inductance.

[Sixth group of measured results]

In the following, an equivalent magnetic circuit experiment is performed with respect to the choke 600a of FIG. 11A and the choke 600b of FIG. 11D, where the material and volume of the magnetic core of these chokes are the same. FIG. 12 is a schematic diagram of a magnetic circuit of a choke. For convenience of explanation, FIG. 12 only shows a first core body and a second core body of the core, and FIG. 12 (a) represents a second core body 717a. It is located on the center pillar 714a and the side wall portion 712a of the first core body 711a, and the second core body 717a has no opening. (B) represents the choke 600a, that is, the second core body 617 is disposed on the side wall portion 612b. Meanwhile, (c) represents the choke 600b, that is, both ends of the second magnetic core body 617 are disposed on the side wall portion 612b '. fine The dashed line indicates the pitch (only one side is shown), and the thick dashed line indicates the equivalent magnetic path (only one side is shown). Table 10 shows the experimental data of the magnetic permeability of the equivalent magnetic circuit with one-sided spacing.

According to Table 10, it is known that the influence of the single-sided pitch on the magnetic permeability is the smallest in the choke 600a, the second in the choke 600b, and the largest in the choke 700a. It can be seen that the choke 600a and the choke 600b proposed by the present invention can effectively reduce the influence of the single-sided distance on the magnetic permeability, and make the chokes 600a and 600b have a larger value than the choke 700a.

In summary, the chokes 300a, 300c ~ 300f, 400a ~ 400c, 500a ~ 500e, 600a, 600b of the present invention have at least the following advantages:

1. The choke assembly has high stability and reduces the variability of the sense value.

2. The efficiency of the choke of the present invention is greater than that of the conventional choke.

3. The wire can be wound into a hollow coil by using automatic equipment, which can effectively reduce the labor cost of the wire in the winding process.

4. The position of the second magnetic core body relative to the first magnetic core body can be controlled to match different coils to adjust the inductance, so that the chokes of different inductances can use the same magnetic core, thereby saving mold costs.

5. When the choke has a wire groove, it can effectively reduce the appearance width of the choke and the distance between the ends of the coil, and can reduce the pad spacing on the circuit board.

6. Set the opening on the second magnetic core body or bottom plate with the assembly surface, so that the center pillar will protrude toward the assembly surface, so that the protruding center pillar will not affect the appearance of the choke.

7. The choke has a housing, a package, a magnetic housing, or a magnetic core with a side wall portion, which can be used to replace the magnetic glue and effectively avoid the problem of overflowing or vertical flow of the magnetic glue.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (12)

An element having inductance includes: a pre-wound hollow coil having a first plurality of winding coils located at an innermost layer and a second plurality of winding coils located at an outermost layer, and two linear ends, wherein the two The linear end portions are respectively connected to the bottoms of the first plurality of coils and the second plurality of coils; a package encapsulating the pre-wound hollow coil and forming an upper surface and a lower surface; and a magnetic core body Disposed below the lower surface and in contact with the lowermost windings of the first plurality of windings and the lowermost windings of the second plurality of windings, respectively, wherein the two linear ends are respectively formed by the The upper part of the magnetic core body extends below the bottom surface of the magnetic core body as two pins of the element with inductance to connect an external circuit. The component with inductance as described in item 1 of the patent application scope, wherein the two pins are two through-hole pins. The component with inductance as described in item 1 of the scope of patent application, wherein the two pins are surface-adhesive pins. A choke includes: a pre-wound hollow coil having a first plurality of winding coils located at an innermost layer and a second plurality of winding coils located at an outermost layer, and two linear ends, wherein the two straight lines The end portions are respectively connected to the bottoms of the first plurality of winding coils and the second plurality of winding coils. A package body covers the pre-wound hollow coil and has an upper surface and a lower surface. The upper surface is located above the hollow coil and covers the upper surface of the hollow coil; and a magnetic core is disposed below the lower surface of the package and is respectively connected with the lowermost winding layer of the first plurality of winding coils And the lowermost windings of the second plurality of windings are in contact; wherein both ends of the linear shape extend from above the magnetic core body to below the bottom surface of the magnetic core body as two of the choke Pin to connect an external circuit. The choke according to item 4 of the scope of the patent application, wherein the magnetic core body is a magnetic bottom plate, and the choke further includes a magnetic center post, which is disposed in the pre-wound formed package after being packaged. Inside the hollow coil. The choke according to item 5 of the scope of patent application, wherein the magnetic bottom plate has an opening, and a part of the magnetic center pillar is inserted into the opening and connected to the magnetic bottom plate. The choke according to item 6 of the scope of patent application, wherein the two pins are two through-hole pins. The choke according to item 6 of the scope of the patent application, wherein the two pins are surface-adhesive pins. The choke according to item 5 of the scope of patent application, further comprising a magnetic top plate, the magnetic center post and the magnetic top plate are integrally formed, and the hollow coil is located between the magnetic top plate and the magnetic bottom plate. A method for manufacturing an element with inductance, comprising: packaging a pre-wound hollow coil with a package body to form an upper surface and a lower surface, wherein the hollow coil has a first plurality of coils located at an innermost layer and a The second plurality of winding coils in the outermost layer and two linear ends, wherein the two linear ends are respectively connected to the bottom of the first plurality of winding coils and the second plurality of winding coils; a first magnetic field is provided. A core body, the first magnetic core body having a cylinder; at least a part of the cylinder of the first magnetic core body is placed in the packaged pre-formed hollow coil; and a second magnetic core The core is disposed below the lower surface and is in contact with the lowermost windings of the first plurality of windings and the lowermost windings of the second plurality of windings, respectively, wherein the two linear ends are respectively Extending from above the second magnetic core body to below the bottom surface of the second magnetic core body as two pins of the element with inductance to connect an external circuit. The method according to item 10 of the scope of patent application, wherein the second magnetic core body has an opening; a second part of the pillar is inserted into the opening to be connected with the second magnetic core body. The method according to item 10 of the patent application, wherein the first magnetic core further has a top, the top is connected to the pillar, and at least a part of the top is disposed on the upper surface.