Magnetic component

Abstract

A magnetic element includes a magnetic core and at least one coil. The magnetic core includes at least one outer post and an inner post. The inner post is separated from the inner surface of one of the magnetic cores. The inner post is at least partially divided into a plurality of separate portions along its length. At least one coil is wound around the inner post.

Description

Technical Field

[0001] This invention relates to a magnetic element, and more particularly to a magnetic element that can effectively improve heat dissipation efficiency. Prior Technology

[0002] To meet the demands of fast charging for electric vehicles, the operating power is increasing, leading to higher heat generation from the electronic components. Magnetic components in on-board chargers (OBCs), such as transformers, generate heat due to losses during operation. Uneven heating creates additional thermal stress on the transformer core, which in turn increases core losses. Continuous cycles of this heat buildup prevent the heat from converging, resulting in excessively high temperatures and losses, and in severe cases, irreversible damage and breakage of the core. Summary of the Invention

[0003] The present invention provides a magnetic element that can effectively improve heat dissipation efficiency to solve the above-mentioned problems.

[0004] According to one embodiment, the magnetic element of the present invention includes a magnetic core and at least one coil. The magnetic core includes at least one outer post and one inner post. The inner post is separated from the inner surface of one of the magnetic cores. The inner post is at least partially divided into a plurality of separate portions along its length. At least one coil is wound around the inner post.

[0005] In this embodiment, the inner column is separated from the inner surface of the magnetic core and is at least partially divided into a plurality of separation portions along the length of the inner column. Since the inner column has the highest temperature and heat is not easily dissipated from it, dividing the inner column into at least a plurality of separation portions along its length can reduce the cross-sectional area of ​​the inner column perpendicular to the magnetic flux direction, thereby reducing the eddy current loss of the magnetic core.

[0006] In one embodiment, the magnetic element further includes a heat sink and a thermally conductive filler. The heat sink is disposed on the magnetic core. The heat sink contacts a top surface and a side surface of the magnetic core. The side surface has an opening. The heat sink covers the opening. The thermally conductive filler fills the opening on the side surface. The thermally conductive filler covers a portion of, but does not completely cover, at least one coil. The shape of the thermally conductive filler at the opening is the same as the shape of the opening covered by the heat sink. One end of at least one coil protrudes from the magnetic core. The heat sink has a protrusion. The protrusion is thermally coupled to the end of at least one coil.

[0007] In this embodiment, the heat sink covers the opening on the side of the magnetic core, and the thermally conductive filler fills the opening on the side. The thermally conductive filler covers a portion of at least one coil, but does not completely cover at least one coil. This saves on the amount of thermally conductive filler used.

[0008] In one embodiment, at least one coil includes an upper first coil, a lower first coil, and a second coil. The cross-sectional area of ​​the upper and lower first coils is larger than the cross-sectional area of ​​the second coil. The upper first coil is disposed relative to the upper inner surface of the magnetic core. The lower first coil is disposed relative to the lower inner surface of the magnetic core. The second coil is disposed between the upper and lower first coils. The lower first coil, the second coil, and the upper first coil are stacked from bottom to top. A gap exists between the upper inner surface of the magnetic core and the upper first coil. The magnetic element further includes a thermally conductive material. The thermally conductive material is partially disposed in the gap and contacts the upper first coil and the upper inner surface of the magnetic core. There is no gap between the lower inner surface of the magnetic core and the lower first coil. The lower first coil is thermally coupled to the lower inner surface of the magnetic core. The second coil does not contact the thermally conductive material.

[0009] In this embodiment, since the heat-conducting material is partially disposed in the gap between the inner surface of the magnetic core and the upper first coil, the heat of the upper first coil can be transferred to the upper part of the magnetic core through the heat-conducting material, thereby dissipating the heat of the upper first coil.

[0010] In one embodiment, the magnetic element further includes a first heat sink and a second heat sink. The first heat sink is disposed on a first side and a top side of one of the magnetic cores. The first heat sink extends from the first side to the top side. The second heat sink is disposed on a second side and a top side of one of the magnetic cores. The first side and the second side are opposite to each other. The second heat sink extends from the second side to the top side. The first heat sink and the second heat sink have a first joint area, a second joint area, and a third joint area on the top side between the first side and the second side. The third joint area is located between the first joint area and the second joint area. The projections of the first joint area and the second joint area do not overlap with the inner post. The projection of at least one of the first heat sink and the second heat sink overlaps with the inner post.

[0011] In this embodiment, the projection of at least one of the first and second heat sinks overlaps with the inner column, allowing heat from the inner column to be transferred via at least one of the first and second heat sinks to the thermally conductive filler on the side or below, and then to the heat dissipation surface below. Furthermore, the projections of the first and second joint areas do not overlap with the inner column, allowing the joint spacing between the first and second joint areas to be greater than the joint spacing of the third joint area. This absorbs the larger length tolerance of the first or second heat sink in the horizontal direction of the magnetic core without affecting the heat dissipation efficiency.

[0012] In one embodiment, the magnetic element further includes a plastic housing, an insulating thermally conductive substrate, and a thermally conductive filler. The plastic housing is disposed on the insulating thermally conductive substrate. The magnetic core is disposed in the plastic housing and located on the insulating thermally conductive substrate. The thermally conductive filler fills the plastic housing.

[0013] When magnetic components with aluminum housings are used in high-voltage devices (e.g., greater than 67V), an insulating layer needs to be placed inside the housing, which is costly and has poor insulation. Therefore, in this embodiment, the housing of the magnetic component made of plastic not only has better insulation but also concentrates and transfers most of the heat to the insulating thermally conductive substrate at the bottom. Furthermore, when filling with thermally conductive filler, the plastic housing can be used to cover the filler.

[0014] In one embodiment, the magnetic element further includes a housing. The housing has a support structure. A terminal is disposed on the support structure. One end of at least one coil is engaged with the terminal on the support structure. The support structure extends downward from the terminal to a support surface where the housing is located.

[0015] In this embodiment, since the support structure extends downward from the terminal to the support surface where the housing is located, the bonding force between the end of the coil and the terminal is directly transmitted to the support surface through the support structure, so that the support structure can withstand a bonding force of, for example, 650 tons.

[0016] In one embodiment, at least one coil includes at least one primary-side coil and at least one secondary-side coil stacked on top of each other. The at least one primary-side coil is formed by stacking multiple turns of round wire. The at least one secondary-side coil has a foil structure. The at least one secondary-side coil has a heat dissipation portion protruding from the magnetic core. The at least one primary-side coil is recessed between the at least one secondary-side coil and does not extend to the heat dissipation portion of the at least one secondary-side coil. The magnetic element further includes a thermally conductive filler. The thermally conductive filler portion is filled between the at least one primary-side coil and the at least one secondary-side coil.

[0017] In this embodiment, at least one heat dissipation portion of the secondary coil can contact a heat dissipation surface of a heat sink to increase the heat dissipation area of ​​the magnetic element. Furthermore, the heat from the recessed primary coil can be transferred to an external heat dissipation interface via the thermally conductive filler and the secondary coil, thereby achieving better heat dissipation efficiency in a more economical (lower cost) manner.

[0018] The advantages and spirit of this invention can be further understood from the following detailed description of the invention and the accompanying drawings. Simple Explanation of the Diagram

[0019] Figure 1 is a perspective view of a magnetic element according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the magnetic element in Figure 1. Figure 3 is a top view of the inner column in Figure 2. Figure 4 is a cross-sectional view of a magnetic element according to another embodiment of the present invention. Figure 5 is a cross-sectional view of a magnetic element according to another embodiment of the present invention. Figure 6 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 7 is a partial exploded view of the magnetic element in Figure 6. Figure 8 is a three-dimensional view of a portion of the coil covered by thermally conductive filler, rather than a complete coil. Figure 9 is a cross-sectional view of the magnetic element in Figure 6. Figure 10 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 11 is a partial exploded view of the magnetic element in Figure 10. Figure 12 is a cross-sectional view of the magnetic element in Figure 10. Figure 13 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 14 is a partial exploded view of the magnetic element in Figure 13. Figure 15 is a cross-sectional view of the magnetic element in Figure 13 along line XX. Figure 16 is a cross-sectional view of the magnetic element in Figure 13 along the YY line. Figure 17 is a top view of a magnetic element according to another embodiment of the present invention. Figure 18 is a top view of a magnetic element according to another embodiment of the present invention. Figure 19 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 20 is an exploded view of the magnetic element in Figure 19. Figure 21 is a cross-sectional view of the magnetic element in Figure 19. Figure 22 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 23 is a cross-sectional view of the magnetic element in Figure 22. Figure 24 is a perspective view of a magnetic element according to another embodiment of the present invention. Figure 25 is an exploded view of the magnetic element in Figure 24. Figure 26 is an exploded view of the secondary coil and insulating pad shown in Figure 25. Figure 27 is a cross-sectional view of the magnetic element in Figure 24. Implementation

[0020] Please refer to Figures 1 to 3. Figure 1 is a perspective view of the magnetic element 1 according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the magnetic element 1 in Figure 1, and Figure 3 is a top view of the inner column 100 in Figure 2.

[0021] The magnetic element 1 of this invention can be a reactor, transformer, inductor, or other magnetic element. As shown in Figures 1 and 2, the magnetic element 1 includes a magnetic core 10, at least one coil 12, and a support 13. The magnetic core 10 includes an inner post 100 and at least one outer post 102. In this embodiment, the magnetic core 10 may include a first core 10a and a second core 10b disposed on the first core 10a, wherein the inner post 100 may be a central post disposed between the first core 10a and the second core 10b, and the two outer posts 102 may be side posts extending from around the first core 10a. It should be noted that the type of the first core 10a and the second core 10b may be determined according to the actual application, and this invention is not limited to the embodiment shown in the figures.

[0022] In this embodiment, at least one coil 12 is wound around the inner post 100, and the outer post 102 has no coil wound around it. The type of coil 12 can be round wire, rectangular wire, or multi-strand wire. The inner post 100 is separated from the upper inner surface 104 of one of the magnetic cores 10. In this embodiment, the inner post 100 (at least one part of the inner post 100) can be further separated from the lower inner surface 106 of one of the magnetic cores 10, such that a part of the inner post 100 is suspended or separated between the upper inner surface 104 and the lower inner surface 106. The upper inner surface 104 can be provided by the second core 10b, and the lower inner surface 106 can be provided by the first core 10a. A support 13 is disposed between the first core 10a and the second core 10b to support the suspended inner post 100. At least one coil 12 is wound around the support 13 and the inner post 100. In addition, a gasket 11 may be disposed between the inner post 100 and the upper inner surface 104 of the magnetic core 10, and another gasket 11 may be disposed between the inner post 100 and the lower inner surface 106 of the magnetic core 10.

[0023] As shown in Figure 3, the inner column 100 is at least partially divided into a plurality of separate portions 1000 along one of its length directions. Preferably, the length L2 of the plurality of separate portions 1000 may be greater than 1 / 3 of the overall length L1 of the inner column 100 between the upper inner surface 104 and the lower inner surface 106 of the magnetic core 10. In this embodiment, the length L2 of the plurality of separate portions 1000 may be equal to the overall length L1 of the inner column 100. For example, the inner column 100 may be completely cut along its length direction to form a plurality of separate portions 1000, as shown in Figure 2. Furthermore, the inner column 100 may be cut from the center, and the volumes of the plurality of separate portions 1000 may be identical. As shown in Figure 3, the inner column 100 may be equally divided into four separate portions 1000 along its length direction, but this is not a limitation. The number, volume, and length of the separate portions 1000 may be determined according to the actual application. Furthermore, a thermally conductive filler 16 can be filled between the separation sections 1000 to improve heat dissipation efficiency, as shown in Figure 2. The thermal conductivity of the thermally conductive filler 16 can be greater than 0.3 W / mk, and the material of the thermally conductive filler 16 can include epoxy resin, silicone, polyurethane (PU), phenolic resins, thermoplastic polyethylene terephthalate (PET), polyamide (PA), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), etc. Moreover, in some embodiments, a thermally conductive sheet 17 (e.g., made of metal or ceramic) with a thermal conductivity greater than that of the thermally conductive filler 16 can be provided between the plurality of separation sections 1000, and the thermally conductive sheet 17 cooperates with the thermally conductive filler 16 covering the inner column 100, thereby reducing core loss, inner column temperature, and core stress.

[0024] Please refer to Figure 4, which is a cross-sectional view of the magnetic element 1 according to another embodiment of the present invention. As shown in Figure 4, the length L2 of the plurality of separate portions 1000 can be equal to 1 / 2 of the overall length L1 of the inner column 100.

[0025] Please refer to Figure 5, which is a cross-sectional view of the magnetic element 1 according to another embodiment of the present invention. As shown in Figure 5, the inner column 100 can be connected to the first core 10a, and there can be a suspended (or separate) inner column 100' above the inner column 100. The length L2 of the plurality of separate portions 1000 can be equal to 1 / 2 of the overall length L1 of the inner column 100. Similar to the embodiment shown in Figure 4, the length L2 of the plurality of separate portions 1000 shown in Figure 5 can also be equal to 1 / 2 of the overall length L1 of the inner column 100. In addition, a spacer 11 can be disposed between the inner column 100' and the upper inner surface 104 of the magnetic core 10, and another spacer 11 can be disposed between the inner column 100 and the inner column 100'.

[0026] As described above, the inner column 100 is separated from the inner surface 104 of the magnetic core 10, and is at least partially divided into a plurality of separation portions 1000 along the length of the inner column 100. Since the inner column 100 has the highest temperature and heat is not easily dissipated from it, dividing the inner column 100 into at least a plurality of separation portions 1000 along its length reduces the cross-sectional area of ​​the inner column 100 perpendicular to the magnetic flux direction, thereby reducing eddy current losses in the magnetic core 10. Furthermore, this invention only cuts the inner column 100, without cutting the first core 10a and / or the second core 10b. Therefore, the structure of this invention is easy to assemble, and the assembly tolerance is small.

[0027] Please refer to Figures 6 to 9. Figure 6 is a perspective view of the magnetic element 2 according to another embodiment of the present invention. Figure 7 is a partial exploded view of the magnetic element 2 in Figure 6. Figure 8 is a perspective view of a portion of the coil 12 covered by the thermally conductive filler 16, but not completely covering the coil 12. Figure 9 is a cross-sectional view of the magnetic element 2 in Figure 6.

[0028] In this embodiment, the magnetic element 2 further includes a heat sink 14, a thermally conductive filler 16, and an insulating element 18, as shown in Figures 6 to 9. The heat sink 14 is disposed on the magnetic core 10, wherein the heat sink 14 contacts a top surface 108 and a side surface 110 of the magnetic core 10. The side surface 110 has an opening 1100, and the heat sink 14 covers the opening 1100. The thermally conductive filler 16 fills the opening 1100 of the side surface 110. The thermally conductive filler 16 covers a portion of at least one coil 12 but does not completely cover at least one coil 12, as shown in Figure 8. At this time, the shape of the thermally conductive filler 16 at the opening 1100 is the same as the shape of the opening 1100 covered by the heat sink 14. In addition, an end 120 of at least one coil 12 may protrude from the magnetic core 10, and the heat sink 14 may have a protrusion 140, the protrusion 140 being thermally coupled to the end 120 of at least one coil 12.

[0029] Furthermore, after the heat sink 14 covers the opening 1100, the thermally conductive filler 16 is filled into the magnetic core 10 through another opening opposite to the opening 1100. This ensures that the thermally conductive filler 16 fills the opening 1100 and covers a portion of at least one coil 12 near the opening 1100, while leaving the other portion of at least one coil 12 away from the opening 1100 uncovered. This saves on the amount of thermally conductive filler 16 used. To balance the temperature, the coil 12 not covered by the thermally conductive filler 16 can be thermally coupled to the protrusion 140 of the heat sink 14.

[0030] In this embodiment, an insulating member 18 may be provided between the end 120 of at least one coil 12 and the protrusion 140 of the heat sink 14. The insulating member 18 can prevent the protrusion 140 from contacting both ends of the coil 12 simultaneously and causing a short circuit. In some embodiments, the outer surface of the heat sink 14 may have a thicker electrical insulating layer, so that the insulating member 18 can be omitted.

[0031] Please refer to Figures 10 to 12. Figure 10 is a perspective view of the magnetic element 3 according to another embodiment of the present invention, Figure 11 is a partial exploded view of the magnetic element 3 in Figure 10, and Figure 12 is a cross-sectional view of the magnetic element 3 in Figure 10.

[0032] In this embodiment, at least one coil 12 may include an upper first coil 12a, a lower first coil 12b, and a second coil 12c, as shown in Figure 12. The upper first coil 12a and the lower first coil 12b may be flat structures, and the second coil 12c may be formed by stacking multiple turns of circular wire, such that the cross-sectional area of ​​the upper first coil 12a and the lower first coil 12b may be larger than the cross-sectional area of ​​the second coil 12c, but this is not a limitation. The upper first coil 12a is disposed relative to the upper inner surface 104 of the magnetic core 10, the lower first coil 12b is disposed relative to the lower inner surface 106 of the magnetic core 10, and the second coil 12c is disposed between the upper first coil 12a and the lower first coil 12b. The lower first coil 12b, the second coil 12c, and the upper first coil 12a are stacked from bottom to top, and there is a gap G between the upper inner surface 104 of the magnetic core 10 and the upper first coil 12a to absorb assembly tolerances.

[0033] In this embodiment, the magnetic element 3 further includes a thermally conductive material 30. The thermally conductive material 30 is partially disposed in the gap G and contacts the upper first coil 12a and the upper inner surface 104 of the magnetic core 10, allowing heat from the upper first coil 12a to be transferred to the upper part of the magnetic core 10 via the thermally conductive material 30, thereby dissipating the heat from the upper first coil 12a. The thermally conductive material 30 can be a gap filler, a thermal pad, or other thermal interface material, but is not limited thereto. Furthermore, there is no gap between the lower inner surface 106 of the magnetic core 10 and the lower first coil 12b; the lower first coil 12b is thermally coupled to the lower inner surface 106 of the magnetic core 10, and the second coil 12c does not contact the thermally conductive material 30.

[0034] In this embodiment, as shown in Figure 11, the ratio of the area A1 of the thermally conductive material 30 to the area A2 of the first coil 12a covered by the magnetic core 10 can be between 30% and 50%.

[0035] In this embodiment, the magnetic element 3 further includes a bracket 32, which is sleeved on the inner post 100. The bracket 32 ​​has an upper boss 320 and a lower boss 322, which correspond to the upper inner surface 104 and the lower inner surface 106, respectively. An upper first coil 12a is disposed on the upper side of one of the upper bosses 320, and a lower first coil 12b is disposed on the lower side of one of the lower bosses 322, such that the upper first coil 12a is disposed relative to the upper inner surface 104 of the magnetic core 10, and the lower first coil 12b is disposed relative to the lower inner surface 106 of the magnetic core 10. A second coil 12c is located between the upper boss 320 and the lower boss 322, and a heat dissipation gap exists between the second coil 12c and the magnetic core 10 or the bracket 32.

[0036] In this embodiment, the current value and heat energy of the first coil 12a are greater than those of the second coil 12c. With the above structure, the amount of heat-conducting material 30 can be reduced by 94%.

[0037] Please refer to Figures 13 to 16. Figure 13 is a perspective view of the magnetic element 4 according to another embodiment of the present invention. Figure 14 is a partial exploded view of the magnetic element 4 in Figure 13. Figure 15 is a cross-sectional view of the magnetic element 4 in Figure 13 along the XX line. Figure 16 is a cross-sectional view of the magnetic element 4 in Figure 13 along the YY line.

[0038] In one embodiment, the magnetic element 4 further includes a first heat sink 40 and a second heat sink 42, as shown in Figures 13 to 16. In this embodiment, three magnetic elements 4 can be disposed in a single housing 44, but this is not a limitation. In one magnetic element 4, the first heat sink 40 may be disposed on a first side 112 and a top side 114 of one of the magnetic cores 10, and the second heat sink 42 may be disposed on a second side 116 and a top side 114 of one of the magnetic cores 10, wherein the first side 112 and the second side 116 are opposite to each other. Further, the first heat sink 40 extends from the first side 112 to the top side 114, and the second heat sink 42 extends from the second side 116 to the top side 114.

[0039] In this embodiment, the first heat sink 40 and the second heat sink 42 have a first joint area R1, a second joint area R2, and a third joint area R3 on the top side 114 between the first side 112 and the second side 116. The third joint area R3 is located between the first joint area R1 and the second joint area R2. In this embodiment, the extending direction of the third joint area R3 is perpendicular to the extending direction of the first joint area R1 and the second joint area R2, but is not limited thereto. Furthermore, the projections of the first joint area R1 and the second joint area R2 do not overlap with the inner pillar 100, and the projection of at least one of the first heat sink 40 and the second heat sink 42 overlaps with the inner pillar 100, as shown in Figures 13, 15, and 16.

[0040] In this embodiment, the magnetic element 4 further includes a thermally conductive filler 46, which covers the lower part of the magnetic core 10 and is thermally coupled to a heat dissipation surface 48 below the lower part.

[0041] To increase the heat dissipation path of the inner column 100, the projection of at least one of the first heat sink 40 and the second heat sink 42 overlaps with the inner column 100, so that the heat of the inner column 100 can be transferred to the thermally conductive filler 46 on the side or below via at least one of the first heat sink 40 and the second heat sink 42, and then to the heat dissipation surface 48 below. In addition, the projections of the first joint area R1 and the second joint area R2 do not overlap with the inner column 100, so that the joint spacing D1 and D2 of the first joint area R1 and the second joint area R2 can be greater than the joint spacing D3 of the third joint area R3, so as to absorb the large length tolerance of the first heat sink 40 or the second heat sink 42 in the horizontal direction of the magnetic core 10 without affecting the heat dissipation efficiency.

[0042] Preferably, the projections of the first heat sink 40 and the second heat sink 42 can simultaneously overlap with the inner pillar 100 (that is, the projection of the third joint area R3 can overlap with the inner pillar 100), and the joint spacing D3 of the third joint area R3 can be between 0 and 3 mm. Preferably, the joint spacing D3 of the third joint area R3 can be 0, that is, the first heat sink 40 and the second heat sink 42 are in contact with each other in the third joint area R3, and the first heat sink 40 and the second heat sink 42 can be symmetrical, so that the heat transferred from the inner pillar 100 to the bottom of the first side 112 through the first heat sink 40 is approximately equal to the heat transferred from the inner pillar 100 to the bottom of the second side 116 through the second heat sink 42, thereby optimizing the heat dissipation efficiency and reducing manufacturing costs.

[0043] Please refer to Figure 17, which is a top view of the magnetic element 4 according to another embodiment of the present invention. As shown in Figure 17, the projection of the first heat sink 40 overlaps with the inner post 100, while the second heat sink 42 does not overlap with the inner post 100 (that is, the projection of the third junction area R3 does not overlap with the inner post 100).

[0044] Please refer to Figure 18, which is a top view of the magnetic element 4 according to another embodiment of the present invention. As shown in Figure 18, the extension direction of the third bonding region R3 is inclined relative to the extension directions of the first bonding region R1 and the second bonding region R2.

[0045] Please refer to Figures 19 to 21. Figure 19 is a perspective view of the magnetic element 5 according to another embodiment of the present invention, Figure 20 is an exploded view of the magnetic element 5 in Figure 19, and Figure 21 is a cross-sectional view of the magnetic element 5 in Figure 19.

[0046] In one embodiment, the magnetic element 5 further includes a plastic housing 50, an insulating and thermally conductive substrate 52, and a thermally conductive filler 54, as shown in Figures 19 to 21. In this embodiment, three magnetic elements 5 can be disposed in a single plastic housing 50, but this is not a limitation. The plastic housing 50 is disposed on the insulating and thermally conductive substrate 52, the magnetic core 10 of the magnetic element 5 is disposed in the plastic housing 50 and located on the insulating and thermally conductive substrate 52, and the thermally conductive filler 54 fills the plastic housing 50.

[0047] When magnetic components with aluminum housings are used in high-voltage devices (e.g., greater than 67V), an insulating layer needs to be placed inside the housing, which is costly and has poor insulation. Therefore, in this embodiment, the housing 50 of the magnetic component 5, made of plastic, not only has better insulation but also concentrates and transfers most of the heat to the insulating thermally conductive substrate 52 at the bottom. Furthermore, when filling with thermally conductive filler 54, the plastic housing 50 can be used to cover the thermally conductive filler 54. In this embodiment, the insulating thermally conductive substrate 52 can be a metal core printed circuit board (MCPCB), a ceramic printed circuit board, or an aluminum plate with an insulating layer, possessing both high thermal conductivity and high insulation.

[0048] As shown in Figures 20 and 21, the plastic housing 50 may have a recessed structure 500 and a flow-guiding opening 502, and the thermally conductive filler 54 may cover the recessed structure 500 and the flow-guiding opening 502. Furthermore, the sidewalls between the magnetic elements 5 may have flow-guiding openings 502, allowing the thermally conductive filler 54 to flow between the plurality of magnetic elements 5 during filling. In addition, the bottom of the plastic housing 50 may also have a recessed structure 500, allowing the thermally conductive filler 54 to cover both the recessed structure 500 and the flow-guiding opening 502, thereby reducing the amount of thermally conductive filler 54 used.

[0049] Please refer to Figures 22 and 23. Figure 22 is a perspective view of the magnetic element 6 according to another embodiment of the present invention, and Figure 23 is a cross-sectional view of the magnetic element 6 in Figure 22.

[0050] In one embodiment, the magnetic element 6 further includes a housing 60, as shown in Figures 22 and 23. The housing 60 has a support structure 600. A terminal 62 is disposed on the support structure 600. At least one end 120 of a coil 12 is engaged with the terminal 62 on the support structure 600. The support structure 600 extends downward from the terminal 62 to a support surface P on which the housing 60 is located.

[0051] In this embodiment, since the support structure 600 extends downward from the terminal 62 to the support surface P where the housing 60 is located, the bonding force F between the end 120 of the coil 12 and the terminal 62 is directly transmitted to the support surface P through the support structure 600, allowing the support structure 600 to withstand, for example, a bonding force F of 650 tons. It should be noted that the shape of the support structure 600 can be determined according to the actual application and is not limited to the embodiment shown in the figures.

[0052] Please refer to Figures 24 to 27. Figure 24 is a perspective view of the magnetic element 7 according to another embodiment of the present invention. Figure 25 is an exploded view of the magnetic element 7 in Figure 24. Figure 26 is an exploded view of the secondary coil 12e and the insulating pad 70 in Figure 25. Figure 27 is a cross-sectional view of the magnetic element 7 in Figure 24.

[0053] In one embodiment, at least one coil 12 includes at least one primary coil 12d and at least one secondary coil 12e stacked on top of each other, as shown in Figures 24 to 27. The at least one primary coil 12d may be formed by stacking multiple turns of circular wire. The at least one secondary coil 12e may be a foil structure. As shown in Figure 27, the at least one secondary coil 12e has a heat dissipation portion 122 protruding from the magnetic core 10, and the at least one primary coil 12d is recessed between the at least one secondary coil 12e and does not extend to the heat dissipation portion 122 of the at least one secondary coil 12e. The number of primary coils 12d and secondary coils 12e can be determined according to the actual application. In this embodiment, the magnetic element 7 further includes a thermally conductive filler 16. The thermally conductive filler 16 partially fills the space between the at least one primary coil 12d and the at least one secondary coil 12e.

[0054] In this embodiment, the number of turns of at least one primary coil 12d can be greater than the number of turns of at least one secondary coil 12e. Furthermore, the cross-sectional area, current, and heat energy of the secondary coil 12e can be greater than those of the primary coil 12d. Therefore, the heat dissipation portion 122 of the secondary coil 12e can contact a heat dissipation surface of a heat sink (not shown in the figure) to increase the heat dissipation area of ​​the magnetic element 7. In addition, the heat from the recessed primary coil 12d can be transferred to an external heat dissipation interface via the thermally conductive filler 16 and the secondary coil 12e, thereby achieving better heat dissipation efficiency in a more economical (lower cost) manner.

[0055] In addition, the magnetic element 7 may further include at least one insulating pad 70 disposed between at least one primary coil 12d and at least one secondary coil 12e to improve the insulation between the primary coil 12d and the secondary coil 12e. The thickness of the insulating pad 70 may be between 50 micrometers and 100 micrometers, but is not limited thereto.

[0056] It should be noted that the inner column 100, which is at least partially divided into a plurality of separation sections 1000 (as shown in Figures 2 to 5), can be applied to all of the above-mentioned magnetic elements 2-7. The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the claims of the present invention shall be covered by the present invention.

[0057] 1,2,3,4,5,6,7: Magnetic elements 10: Magnetic core 10a: First Core 10b: Second Core 11: Gasket 12: Coil 12a: Upper first coil 12b: Lower first coil 12c: Second coil 12d: Primary coil 12e: Secondary coil 13,32: Bracket 14: Heat sink 16,46,54: Thermally conductive fillers 17: Thermal conductive sheet 18: Insulating components 30: Thermal conductive materials 40: First heat sink 42: Second heat sink 44, 60: Casing 48: Heat dissipation surface 50: Plastic casing 52: Insulated thermally conductive substrate 62:Terminal 70: Insulating gasket 100,100': inner column 102: Outer Column 104: Upper inner surface 106: Lower inner surface 108: Top surface 110: Side view 112: First side 114: Top Side 116: Second side 120:End 122: Heat dissipation section 140: Protrusion 320: Upper boss 322: Lower boss 500: Inward-shrinking structure 502: Flow guide opening 600: Supporting structure 1000: Separation section 1100: Opening A1, A2: Area D1, D2, D3: Joint spacing F: Cohesion force G: Gap L1, L2: Length P: Support surface R1: First junction area R2: Second junction area R3: Third junction area X, Y: Profile lines

Claims

1. A magnetic element comprising: a magnetic core including at least one outer post and an inner post, the inner post being separated from an upper inner surface of the magnetic core, the inner post being at least partially divided into a plurality of separation portions along a length direction of the inner post, the separation grooves of the plurality of separation portions extending along the length direction of the inner post to the upper inner surface and the lower inner surface of the magnetic core forming a continuous integral structure, the separation grooves being disposed only on the inner post between the upper inner surface and the lower inner surface of the magnetic core, the separation grooves dividing only the inner post; and at least one coil wound around the inner post.

2. The magnetic element as claimed in claim 1, wherein at least one portion of the inner post is separated from the lower inner surface of the magnetic core, such that the portion of the inner post is suspended or separated between the upper inner surface and the lower inner surface.

3. The magnetic element as claimed in claim 1, wherein the length of the plurality of separate portions is greater than 1 / 3 of the length of the inner column.

4. The magnetic element as claimed in claim 1, wherein the inner column is cut from the center and the plurality of separate portions have the same volume.

5. The magnetic element as claimed in claim 1, wherein a thermally conductive sheet with a thermal conductivity greater than that of a thermally conductive filler is disposed between the plurality of separation portions, and the thermally conductive sheet cooperates with the thermally conductive filler covering the inner column.

6. The magnetic element as claimed in claim 1, further comprising a heat sink and a thermally conductive filler, wherein the heat sink is disposed on the magnetic core, the heat sink contacts a top surface and a side surface of the magnetic core, the side surface having an opening, the heat sink covering the opening, the thermally conductive filler filling the opening on the side surface, the thermally conductive filler covering a portion of but not completely covering the at least one coil, the thermally conductive filler having a shape at the opening that is the same as the shape of the opening covered by the heat sink, one end of the at least one coil protruding from the magnetic core, the heat sink having a protrusion thermally coupled to the end of the at least one coil.

7. The magnetic element as claimed in claim 6, wherein an insulating member is provided between the end of the at least one coil and the protrusion of the heat sink.

8. The magnetic element as claimed in claim 1, wherein the at least one coil comprises an upper first coil, a lower first coil, and a second coil, the cross-sectional areas of the upper first coil and the lower first coil being larger than the cross-sectional area of ​​the second coil, the upper first coil being disposed opposite the upper inner surface of the magnetic core, the lower first coil being disposed opposite the lower inner surface of the magnetic core, and the second coil being disposed between the upper first coil and the lower first coil; the lower first coil, the second coil, and the upper first coil are stacked from bottom to top, and a gap exists between the upper inner surface of the magnetic core and the upper first coil; the magnetic element further comprises a thermally conductive material, the thermally conductive material being partially disposed in the gap and contacting the upper first coil and the upper inner surface of the magnetic core, the lower inner surface of the magnetic core and the lower first coil having no gap, the lower first coil being thermally coupled to the lower inner surface of the magnetic core, and the second coil not contacting the thermally conductive material.

9. The magnetic element as claimed in claim 8, wherein the ratio of the area of ​​the thermally conductive material to the area of ​​the upper first coil covered by the magnetic core is between 30% and 50%.

10. The magnetic element as claimed in claim 8, wherein the upper first coil and the lower first coil are flat plate structures, and the second coil is formed by stacking multiple turns of round wire.

11. The magnetic element as described in claim 8 further includes a bracket fitted onto the inner post, wherein the bracket has an upper boss and a lower boss, the upper boss and the lower boss respectively corresponding to the upper inner surface and the lower inner surface, the upper first coil is disposed on the upper side of one of the upper bosses, the lower first coil is disposed on the lower side of one of the lower bosses, the second coil is located between the upper boss and the lower boss, and a heat dissipation gap exists between the second coil and the magnetic core or the bracket.

12. The magnetic element as claimed in claim 1, further comprising: a first heat sink disposed on a first side and a top side of one of the magnetic cores, the first heat sink extending from the first side to the top side; and a second heat sink disposed on a second side and the top side of one of the magnetic cores, the first side and the second side opposite to each other, the second heat sink extending from the second side to the top side; wherein, The first heat sink and the second heat sink have a first joint area, a second joint area and a third joint area on the top side between the first side and the second side. The third joint area is located between the first joint area and the second joint area. The projections of the first joint area and the second joint area do not overlap with the inner column. The projection of at least one of the first heat sink and the second heat sink overlaps with the inner column.

13. The magnetic element as claimed in claim 12, wherein the projection of the third junction region overlaps with the inner post.

14. The magnetic element as claimed in claim 12, wherein the bonding distance between the first bonding region and the second bonding region is greater than the bonding distance between the third bonding region.

15. The magnetic element as claimed in claim 12, wherein the bonding spacing of the third bonding region is between 0 and 3 mm.

16. The magnetic element as claimed in claim 12 further includes a thermally conductive filler covering a lower portion of the magnetic core and thermally coupled to a heat dissipation surface below the lower portion.

17. The magnetic element as claimed in claim 12, wherein the first heat sink and the second heat sink are symmetrically structured.

18. The magnetic element as claimed in claim 12, wherein the first heat sink and the second heat sink are in contact with each other at the third junction area.

19. The magnetic element as claimed in claim 1, further comprising a plastic housing, an insulating thermally conductive substrate, and a thermally conductive filler, wherein the plastic housing is disposed on the insulating thermally conductive substrate, the magnetic core is disposed in the plastic housing and located on the insulating thermally conductive substrate, and the thermally conductive filler is filled in the plastic housing.

20. The magnetic element as claimed in claim 19, wherein the plastic housing has a recessed structure and a flow-guiding opening, and the thermally conductive filler covers the recessed structure and the flow-guiding opening.

21. The magnetic element as claimed in claim 1, further comprising a housing having a support structure, a terminal disposed on the support structure, an end of the at least one coil being engaged with the terminal on the support structure, the support structure extending downward from the terminal to a support surface on which the housing is located.

22. The magnetic element as claimed in claim 1, wherein the at least one coil comprises at least one primary coil and at least one secondary coil stacked on top of each other, the at least one primary coil being formed by multiple turns of round wire, the at least one secondary coil being a foil structure, the at least one secondary coil having a heat dissipation portion protruding from the magnetic core, the at least one primary coil being recessed between the at least one secondary coil and not extending to the heat dissipation portion of the at least one secondary coil, and the magnetic element further comprising a thermally conductive filler portion filling between the at least one primary coil and the at least one secondary coil.

23. The magnetic element as claimed in claim 22, wherein the number of turns of the at least one primary coil is greater than the number of turns of the at least one secondary coil.

24. The magnetic element as claimed in claim 22 further includes at least one insulating pad disposed between the at least one primary coil and the at least one secondary coil.

25. The magnetic element as claimed in claim 1, wherein the dividing groove is disposed on the inner post of the upper and lower separation portion, the dividing groove completely or partially separating the inner post of the upper and lower separation portion laterally.

26. The magnetic element as claimed in claim 1, wherein the dividing groove includes an inner post with a separate upper and lower portion between it and the upper portion of the magnetic core.

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