Composite metal foil and magnetic element

Abstract

The utility model discloses a composite metal foil and a magnetic element. The composite metal foil comprises multiple layers of metal foils and a current sharing magnetic ring assembly. Wherein the multiple layers of metal foils are stacked and arranged in parallel. The current-sharing magnetic ring assembly comprises a plurality of wires and a current-sharing magnetic ring, one end of each wire is connected with the corresponding layer of metal foil, and the other end of each wire is wound on the current-sharing magnetic ring. The composite metal foil can be formed by stacking multiple layers of metal foils in parallel, the degree of freedom of the stacking mode is high, the size of the composite metal foil conductor is small, and the coil filling rate of the magnetic element is high. The current-sharing magnetic ring can provide a magnetic circuit, and the multiple layers of metal foils are wound on the current-sharing magnetic ring through wires to form a plurality of corresponding coils. When the current of any layer of metal foil changes, due to the mutual inductance phenomenon of the coil, the current change trend of each wire is basically consistent, so that the current change trend of each layer of metal foil is basically consistent, and the problem of non-uniform current of multiple layers of metal foils can be reduced or eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic elements, and more specifically to a composite metal foil and a magnetic element. Background Art

[0002] In the related art, the coil winding can be wound by stacking and connecting multiple layers of metal foil in parallel. However, due to the inconsistent curvature of the inner and outer layers of metal foil, the inner and outer currents of the coil winding are unbalanced during operation, which increases the power loss of the coil winding during operation. Utility Model Content

[0003] The utility model provides a composite metal foil and a magnetic element.

[0004] The composite metal foil provided in the embodiment of the utility model comprises a plurality of metal foils and a current-sharing magnetic ring assembly. The plurality of metal foils are stacked and arranged in parallel. The current-sharing magnetic ring assembly comprises a plurality of wires and a current-sharing magnetic ring, one end of each of the wires is connected to a corresponding layer of the metal foil, and the other end of each of the wires is wound on the current-sharing magnetic ring.

[0005] The purpose of the current-sharing magnetic ring is to provide a magnetic circuit. Multiple layers of metal foil can be wound around the current-sharing magnetic ring through wires to form multiple corresponding coils. When the current of any layer of metal foil changes, the current of the wire connected to the metal foil also changes. Due to the mutual inductance of the coil, the current change trend of each wire is basically the same, so that the current change trend of each layer of metal foil is basically the same, which can reduce or eliminate the problem of uneven current of multiple layers of metal foil.

[0006] In some embodiments, the composite metal foil includes an adhesive layer, which is disposed between two adjacent layers of the metal foil and is used to fix the relative positions of the two adjacent layers of the metal foil.

[0007] The adhesive layer can make two adjacent layers of metal foil fit tightly together and not loose, and fix the relative position of the two adjacent layers of metal foil. There is an adhesive layer between each layer of metal foil, multiple layers of metal foil can be stacked together, and the relative position of each layer of metal foil is fixed, which can prevent the metal foil from loosening and falling off.

[0008] In some embodiments, the adhesive layer is a self-adhesive glue or an organic silicone.

[0009] In some embodiments, the composite metal foil includes an insulating member. The insulating paper is disposed between two adjacent layers of the metal foil, and the insulating member is used to insulate and separate the two adjacent layers of the metal foil.

[0010] The insulating member can insulate and separate two adjacent layers of metal foils. Multiple layers of insulating metal foils can be stacked in parallel to form a composite metal foil, which is beneficial for the composite metal foil to form a multi-turn coil winding of a magnetic element.

[0011] In certain embodiments, the insulating member is a polyesterimide paint film or an aromatic amide polymer insulating paper.

[0012] In some embodiments, the composite metal foil further comprises a heat conductor, which is disposed between two adjacent layers of the metal foil and is used to transfer heat between the two adjacent layers of the metal foil.

[0013] When the magnetic element is working, the composite metal foil is energized and heated as a coil winding, and each layer of the metal foil generates heat. The heat conductive member is conducive to the heat dissipation of each layer of the metal foil.

[0014] In some embodiments, the heat conducting member is the heat conducting silica gel. The heat conducting silica gel is also used to fix the relative positions of two adjacent layers of the metal foil.

[0015] The heat-conducting member can be made of heat-conducting silicone. The heat-conducting silicone not only fixes the relative positions of two adjacent layers of metal foil but also has a heat-conducting effect, which is beneficial to the process of composite metal foil.

[0016] In certain embodiments, the composite metal foil comprises a support member, which is disposed between two adjacent layers of the metal foil and is used to increase the distance between the two adjacent layers of the metal foil.

[0017] The support member can increase the distance between the metal foils, thereby increasing the heat dissipation area between two adjacent layers of the metal foils, and each layer of the metal foil dissipates heat.

[0018] The magnetic element provided by the embodiment of the utility model includes the composite metal foil of any one of the above embodiments.

[0019] In some embodiments, the magnetic element includes a magnetic core and a frame. The magnetic core is arranged inside the frame. The composite metal foil includes aluminum foil and copper foil, the copper foil is wound outside the frame, and the aluminum foil is wound outside the copper foil.

[0020] The composite metal foil can be formed by metal foils of different materials. The outer metal foil can be aluminum foil with high ductility, and the inner metal foil can be copper foil with low ductility, which is conducive to winding the composite metal foil on the skeleton.

[0021] In some embodiments, the magnetic element includes a magnetic core and a frame, wherein the magnetic core is arranged inside the frame. The composite metal foil is wound outside the frame to form multiple turns of the coil winding, and two adjacent layers of metal foil are used to form different turns of the coil winding.

[0022] Two adjacent layers of metal foil form coil windings with different turns, which is beneficial to increasing the coil coupling coefficient of each turn of the coil winding.

[0023] In some embodiments, the metal foil includes multiple layers of primary metal foil and multiple layers of secondary metal foil. The primary metal foil and the secondary metal foil are alternately wound on the outside of the frame, the multiple layers of the primary metal foil are used to form the primary coil winding of the magnetic element, and the multiple layers of the secondary metal foil are used to form the secondary coil winding of the magnetic element.

[0024] Two adjacent layers of metal foil can form an additional primary winding and a secondary winding, which is beneficial to increasing the coil coupling coefficient between the primary winding and the secondary winding.

[0025] The composite metal foil provided in the embodiment of the utility model comprises a plurality of metal foils and a current-sharing magnetic ring assembly. The plurality of metal foils are stacked and arranged in parallel. The current-sharing magnetic ring assembly comprises a plurality of wires and a current-sharing magnetic ring, one end of each wire is connected to a corresponding layer of metal foil, and the other end of each wire is wound on the current-sharing magnetic ring.

[0026] The current-sharing magnetic ring can provide a magnetic circuit, and multiple layers of metal foil can be wound around the current-sharing magnetic ring through wires to form multiple corresponding coils. When the current of any layer of metal foil changes, the current of the wire connected to the metal foil also changes. Due to the mutual inductance of the coil, the current change trend of each wire is basically the same, so that the current change trend of each layer of metal foil is basically the same, which can reduce or eliminate the problem of uneven current of multiple layers of metal foil.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 It is a structural schematic diagram of the composite metal foil of the utility model;

[0030] Figure 2 It is a schematic diagram of the magnetic element of the utility model;

[0031] Figure 3 It is a schematic diagram of the magnetic element skeleton of the utility model;

[0032] Figure 4 It is a stacking schematic diagram of the first embodiment of the composite metal foil of the utility model;

[0033] Figure 5It is a stacking schematic diagram of a second embodiment of the composite metal foil of the utility model;

[0034] Figure 6 It is a stacking schematic diagram of a third embodiment of the composite metal foil of the utility model;

[0035] Figure 7 It is a schematic diagram of stacking of the fourth embodiment of the composite metal foil of the utility model;

[0036] Figure 8 It is a stacking schematic diagram of the fifth embodiment of the composite metal foil of the utility model;

[0037] Fig. 9 It is a stacking schematic diagram of the sixth embodiment of the composite metal foil of the utility model;

[0038] Fig.10 It is a schematic diagram of the stacking and magnetic elements of the seventh embodiment of the composite metal foil of the utility model.

[0039] Description of main component symbols:

[0040] Composite metal foil 100, metal foil 110, current balancing magnetic ring assembly 120, wire 121, current balancing magnetic ring 122, adhesive layer 130, insulating member 140, thermal conductive member 150, supporting member 160, packaging film 170, magnetic core 200, skeleton 300, inner side of skeleton 310, outer side of skeleton 320, magnetic element 1000. DETAILED DESCRIPTION

[0041] The embodiments of the present invention are described in detail below, and the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0042] In the related art, the coil winding can be wound by stacking and connecting multiple layers of metal foil in parallel. However, due to the inconsistent curvature of the inner and outer layers of metal foil, the inner and outer currents of the coil winding are unbalanced during operation, which increases the power loss of the coil winding during operation.

[0043] In recent years, with the development of semiconductor power devices and technological advancement, magnetic components have been developing towards high frequency, high power and miniaturization. In various electrical topologies, power magnetic devices mainly include inductors and transformers, and coils are important components of transformers and inductors.

[0044] In order to meet the high power density requirements of high-power magnetic components, copper foil windings are often used in the magnetic coil part, which has the advantages of low coil current density and high window filling factor. Take the copper foil coil as an example. The width of the copper foil is mainly determined by the wire package skeleton. In order to reduce the current density of the winding, thicker copper foil is used for winding.

[0045] As the thickness of copper foil increases, the tensile strength of copper foil will continue to increase. Thicker copper foil is difficult to bend on the coil frame, especially in the coil wrapping method of small-sized, high-power magnetic components. In industrial design, multi-layer copper foil is generally used for coil winding. However, in terms of process, multi-layer copper foil in parallel will have inconsistent bending curvature inside and outside the copper foil, which can easily cause uneven current flow inside and outside the copper foil.

[0046] Reference Figure 1 The present utility model embodiment provides a composite metal foil 100. The composite metal foil 100 includes multiple layers of metal foil 110 and a current-sharing magnetic ring assembly 120. The multiple layers of metal foil 110 are stacked and arranged in parallel. The current-sharing magnetic ring assembly 120 includes multiple wires 121 and a current-sharing magnetic ring 122, one end of each wire 121 is connected to a corresponding layer of metal foil 110, and the other end of each wire 121 is wound on the current-sharing magnetic ring 122.

[0047] Reference Figure 2 The embodiment of the utility model further provides a magnetic element 1000. The magnetic element 1000 includes a composite metal foil 100.

[0048] The purpose of the current-sharing magnetic ring assembly 120 is to provide a magnetic circuit. The multiple layers of metal foil 110 can be wound on the current-sharing magnetic ring 122 through the wire 121 to form a corresponding plurality of coils. When the current of any layer of metal foil 110 changes, the current of the wire 121 connected to the metal foil 110 also changes. Due to the mutual inductance of the coil, the current change trend of each wire 121 is basically the same, so that the current change trend of each layer of metal foil 110 is basically the same, which can reduce or eliminate the problem of uneven current of the multiple layers of metal foil 110.

[0049] Specifically, refer to Figure 2 as well as Figure 3 The magnetic element 1000 may be a transformer, an inductor, etc. The magnetic element 1000 includes a magnetic core 200 and a skeleton 300 . The magnetic core 200 is disposed on the inner side 310 of the skeleton. The composite metal foil 100 may be wound on the skeleton 300 to form a coil winding of the magnetic element 1000 .

[0050] The composite metal foil 100 can be formed by stacking multiple layers of metal foil 110 in parallel, with a high degree of freedom in the stacking method, and the conductor size of the composite metal foil 100 is small, and the coil filling rate of the magnetic element 1000 is high. The multiple layers of metal foil 110 are stacked in parallel before winding the coil, and there will be no problem of uneven edges. At the same time, compared with the single-thickness metal foil 110, the multiple layers of thin metal foil 110 have lower tensile strength and are easy to bend, and there will be no inconsistency in the size of the multiple layers of copper foil.

[0051] After the multiple layers of metal foil 110 are stacked and connected in parallel, a current-balancing magnetic ring assembly 120 may be added to balance the currents of the inner and outer layers of the coil winding during operation, thereby reducing the eddy current loss of the coil winding during operation.

[0052] Each layer of metal foil 110 can be provided with a corresponding outlet position, and the outlet position of each layer of metal foil 110 is connected to one end of a wire 121, and the other end of each wire 121 wound on the current-sharing magnetic ring 122 can be used as a coil. When the current of any layer of metal foil 110 changes, the current of the wire 121 connected to the metal foil 110 also changes. Due to the mutual inductance of the coil, the current change trend of each wire 121 is basically the same, so that the current change trend of each layer of metal foil 110 is basically the same, which can reduce or eliminate the problem of uneven current of multiple layers of metal foil 110.

[0053] For example, the composite metal foil 100 may include a total of n layers of metal foil 110, and the n layers of metal foil 110 may be recorded as metal foil A1 to metal foil An. The metal foil A1 is connected to the wire B1, and the part of the wire B1 wound around the current-sharing magnetic ring 122 is recorded as the coil C1, and the metal foil An is connected to the wire Bn, and the part of the wire Bn wound around the current-sharing magnetic ring 122 is recorded as the coil Cn.

[0054] When the current of a certain layer of metal foil Am changes, the current of the wire Bm wound on the current balancing magnetic ring 122 changes due to the mutual inductance of the coil Cm of the wire Bm wound on the current balancing magnetic ring 122 and other coils wound on the current balancing magnetic ring 122 .

[0055] If the current of metal foil Am increases, the current of wire Bm increases, and the generated magnetic flux also increases, and the increased magnetic flux can generate a positive induced voltage. The generated induced voltage increases the current of other wires 121, so that the current of other layers of metal foil 110 increases with the current of metal foil Am.

[0056] If the current of metal foil Am decreases, the current of wire Bm decreases, and the generated magnetic flux also decreases, and the reduced magnetic flux can generate a reverse induced voltage. The generated induced voltage makes the current of other wires 121 decrease, so that the current of other layers of metal foil 110 follows the current of metal foil Am to decrease.

[0057] Reference Figure 4 In some embodiments, the composite metal foil 100 includes an adhesive layer 130 . The adhesive layer 130 is disposed between two adjacent metal foils 110 , and is used to fix the relative positions of the two adjacent metal foils 110 .

[0058] The layers of metal foil 110 in the composite metal foil 100 are prone to become loose or even partially fall off, which may cause the quality of the composite metal foil 100 to deteriorate.

[0059] The adhesive layer 130 can make two adjacent layers of metal foil 110 fit tightly together and not loosen, and fix the relative positions of the two adjacent layers of metal foil 110. There is an adhesive layer 130 between each layer of metal foil 110, and multiple layers of metal foil 110 can be stacked together, and the relative position of each layer of metal foil 110 is fixed, which can prevent the metal foil 110 from loosening and falling off.

[0060] In some embodiments, the adhesive layer 130 is a self-adhesive adhesive or an organic silicone.

[0061] Optionally, the material of the adhesive layer 130 may be self-adhesive or organic silicone. The material of the adhesive layer 130 may also be silicone adhesive, hot melt adhesive, etc., which can fix the relative position of two adjacent layers of metal foil 110. An adhesive layer 130 may be provided between each layer of metal foil 110, and the relative position of each layer of metal foil 110 is fixed, which can prevent the metal foil 110 from loosening and falling off.

[0062] In some embodiments, the composite metal foil 100 includes an insulating member 140 . The insulating paper is disposed between two adjacent layers of metal foil 110 , and the insulating member 140 is used to insulate and separate the two adjacent layers of metal foil 110 .

[0063] The insulating member 140 can insulate and separate two adjacent layers of metal foil 110 . Multiple layers of insulated metal foil 110 can be stacked in parallel to form a composite metal foil 100 , which is beneficial for the composite metal foil 100 to form a multi-turn coil winding of the magnetic element 1000 .

[0064] Specifically, the material of the insulating member 140 may be polyimide, polyesterimide, polyvinyl chloride, etc. An insulating member 140 may be disposed between each two adjacent layers of metal foil 110 to achieve insulation isolation between the layers of metal foil 110. The insulated and isolated metal foil 110 may form coil windings of different turns of the magnetic element 1000.

[0065] In certain embodiments, the insulating member 140 is a polyesterimide paint film or an aromatic amide polymer insulating paper.

[0066] Reference Figure 4The insulating member 140 may be an insulating film, and the insulating film may be a polyester imide paint film. Each layer of metal foil 110 is wrapped with an insulating film on the outside, and the insulating film is used to insulate and isolate two adjacent layers of metal foil 110. The adhesive layer 130 is used to fix the relative position of the two adjacent layers of insulating film, so as to fix the relative position of the two adjacent layers of metal foil 110.

[0067] When manufacturing the composite metal foil 100 , a layer of insulating film may be sprayed on the surface of each layer of metal foil 110 , an adhesive layer 130 may be applied on the surface of the metal foil 110 , and then the two layers of metal foil 110 are evenly pressed and overlapped to form the composite metal foil 100 .

[0068] Reference Figure 5 The insulating member 140 may be insulating paper, and the insulating paper may be aromatic amide polymer insulating paper. The insulating paper is disposed between two adjacent layers of metal foil 110. The adhesive layer 130 may also be used to fix the position of the insulating paper.

[0069] When manufacturing the composite metal foil 100 , insulating paper is added between each layer of metal foil 110 , and adhesive layers 130 are attached to both sides of the insulating paper. The insulating paper can ensure the insulation between each layer of metal foil 110 .

[0070] Reference Figure 6 In some embodiments, the composite metal foil 100 further includes a heat conductor 150 . The heat conductor 150 is disposed between two adjacent layers of metal foil 110 , and is used to transfer heat between the two adjacent layers of metal foil 110 .

[0071] When the magnetic element 1000 is working, the composite metal foil 100 is energized and generates heat as a coil winding, and each layer of the metal foil 110 generates heat. The heat conducting member 150 is beneficial to the heat dissipation of each layer of the metal foil 110 .

[0072] Specifically, the material of the heat conducting member 150 can be heat conducting silica gel or silicone adhesive, etc. The heat conducting member 150 has excellent heat conducting performance, and the heat conducting member 150 has a relatively high thermal conductivity, which can ensure that each layer of metal foil 110 dissipates heat in time, and prevent the temperature of each layer of metal foil 110 from being too high when the magnetic element 1000 is working.

[0073] Reference Figure 6 In some embodiments, the heat conducting member 150 is a heat conducting silicone rubber. The heat conducting silicone rubber is also used to fix the relative positions of two adjacent layers of metal foil 110 .

[0074] The heat conductive member 150 may be made of heat conductive silicone. The heat conductive silicone not only fixes the relative positions of two adjacent layers of metal foil 110 but also has a heat conductive effect, which is beneficial to the manufacturing process of the composite metal foil 100 .

[0075] Specifically, the thermally conductive silicone has excellent thermal conductivity and viscosity. The thermally conductive silicone can be disposed between two adjacent layers of metal foil 110 , and can fix the relative positions of the two adjacent layers of metal foil 110 while also having a heat conductive effect, which is beneficial to the manufacturing process of the composite metal foil 100 .

[0076] Reference Figure 6 In some embodiments, the composite metal foil 100 includes a support member 160 . The support member 160 is disposed between two adjacent layers of metal foil 110 , and is used to increase the distance between the two adjacent layers of metal foil 110 , so as to increase the heat dissipation area between the two adjacent layers of metal foil 110 .

[0077] The support member 160 can increase the distance between the metal foils 110 , thereby increasing the heat dissipation area between two adjacent layers of metal foils 110 , and each layer of metal foil 110 dissipates heat.

[0078] Specifically, a support bar may be disposed between two adjacent layers of metal foil 110 , and the longer the support bar is, the greater the distance between the two adjacent layers of metal foil 110 is.

[0079] Since the heat conductor 150 is disposed between two adjacent layers of metal foil 110 , the greater the distance between the two adjacent layers of metal foil 110 , the larger the area occupied by the heat conductor 150 between the two adjacent layers of metal foil 110 , the larger the heat dissipation area between the two adjacent layers of metal foil 110 , and the better the heat dissipation effect of the metal foil 110 .

[0080] A support bar can be added between two adjacent layers of metal foil 110 to dissipate heat through the heat-conducting silicone of the metal foil 110, and finally tightened and fixed with a packaging film 170. The packaging film 170 can also play an insulating and isolating effect, and the material of the packaging film 170 can be polyimide, polyester imide, polyvinyl chloride and the like.

[0081] Reference Figure 7 In some embodiments, metal foils 110 of different sizes and thicknesses may be stacked to form a composite metal foil 100. The composite metal foil 100 may include a metal foil A1 and a metal foil A2, wherein the metal foil A1 is disposed above the metal foil A2, and the thickness of the metal foil A1 is greater than that of the metal foil A2.

[0082] Specifically, the composite metal foil 100 may be formed by stacking metal foils 110 of different sizes and thicknesses according to factors such as heat dissipation conditions and magnetic field conditions.

[0083] For example, when the composite metal foil 100 is applied to a water cooling system, the metal foil 110 with a relatively large thickness may be arranged closer to the heat dissipation pipe of the water cooling system, thereby achieving a better heat dissipation effect.

[0084] Since the metal foil 110 close to the magnetic core 200 is on the inner side, the metal foil 110 on the inner side is not easy to dissipate heat, and the metal foil 110 far from the magnetic core 200 is on the outer side, the metal foil 110 on the outer side is easier to dissipate heat than the metal foil 110 on the inner side. The metal foil 110 with a relatively small thickness can be arranged at a position closer to the magnetic core 200, and the metal foil 110 with a relatively large thickness can be arranged at a position farther from the magnetic core 200, which is beneficial to the overall heat dissipation of the composite metal foil 100.

[0085] Reference Figure 8 In some embodiments, each layer of metal foil 110 can form a coil with different windings of the magnetic element 1000. The composite metal foil 100 is wound on the outer side 320 of the frame to form a multi-turn coil winding, and two adjacent layers of metal foil 110 are used to form coil windings with different turns.

[0086] Two adjacent layers of metal foil 110 form coil windings with different turns, which is beneficial to increase the coil coupling coefficient of each coil winding.

[0087] The magnetic element 1000 may include coil windings D1 and D2. The composite metal foil 100 may include metal foils A1 to A2n arranged from top to bottom in sequence. Among them, metal foil A1, metal foil A3, metal foil A5 to metal foil A2n-1 form a coil winding B1, and metal foil A2, metal foil A4, metal foil A6 to metal foil A2n form a coil winding B2, which is beneficial to improve the coupling coefficient between the coil winding B1 and the coil winding B2, and is beneficial to improve the efficiency of energy transmission of the magnetic element 1000.

[0088] In some embodiments, the metal foil 110 includes multiple layers of primary metal foil 110 and multiple layers of secondary metal foil 110. The primary metal foil 110 and the secondary metal foil 110 are alternately wound on the outer side 320 of the skeleton, and the multiple layers of primary metal foil 110 are used to form the primary coil winding of the magnetic element 1000, and the multiple layers of secondary metal foil 110 are used to form the secondary coil winding of the magnetic element 1000.

[0089] Specifically, the magnetic element 1000 can be a transformer. The composite metal foil 100 can include metal foils A1 to A2n arranged from top to bottom in sequence. Among them, metal foil A1, metal foil A3, metal foil A5 to metal foil A2n-1 can be used to form a primary coil winding. Metal foil A2, metal foil A4, metal foil A6 to metal foil A2n can be used to form a secondary coil winding, which is beneficial to improve the coupling coefficient between the primary coil winding and the secondary coil winding of the transformer, and is beneficial to improve the efficiency of the transformer in transmitting energy.

[0090] Reference Fig. 9In some embodiments, different metal materials can be stacked in sections to form a layer of metal foil 110. A layer of metal foil 110 can include metal segment A11, metal segment A12, and metal segment A13 from left to right.

[0091] The material, size and thickness of the metal segments A11, A12 and A13 can be arbitrarily set according to actual needs, and the lamination method of the metal foil 110 has a high degree of freedom.

[0092] Reference Fig.10 In some embodiments, the magnetic element 1000 includes a magnetic core 200 and a skeleton 300. The magnetic core 200 is disposed on the inner side 310 of the skeleton, and the composite metal foil 100 includes aluminum foil and copper foil, the copper foil is wound on the outer side 320 of the skeleton, and the aluminum foil is wound on the outer side of the copper foil.

[0093] The composite metal foil 100 can be formed of metal foils 110 of different materials. The outer metal foil 110 can be made of aluminum foil with high ductility, and the inner metal foil 110 can be made of copper foil with low ductility, which is conducive to winding the composite metal foil 100 on the skeleton 300.

[0094] Specifically, since the metal foil 110 close to the magnetic core 200 is on the inner side, the curvature of the metal foil 110 on the inner side is lower, and the curvature of the winding is lower. The metal foil 110 far from the magnetic core 200 is on the outer side, and the curvature of the metal foil 110 on the outer side is higher than that of the metal foil 110 on the inner side, and the curvature of the winding is higher. The metal foil 110 with better ductility can be set at a position farther away from the magnetic core 200, which is conducive to the overall winding of the composite metal foil 100.

[0095] The composite metal foil 100 may include multiple layers of aluminum foil and multiple layers of copper foil, wherein the multiple layers of copper foil are wound on the outer side of the skeleton 320, and the multiple layers of aluminum foil are wound on the outer side of the multiple layers of copper foil. Aluminum has higher ductility than copper, and the aluminum foil is arranged at a position farther away from the magnetic core 200, which is beneficial to the overall winding of the composite metal foil 100.

[0096] The present utility model embodiment provides a composite metal foil 100 and a magnetic element 1000. The composite metal foil 100 provided in the utility model embodiment includes a multi-layer metal foil 110 and a current-equalizing magnetic ring assembly 120. The multi-layer metal foil 110 is stacked and arranged in parallel. The current-equalizing magnetic ring assembly 120 includes a plurality of wires 121 and a current-equalizing magnetic ring 122, one end of each wire 121 is connected to a corresponding layer of the metal foil 110, and the other end of each wire 121 is wound on the current-equalizing magnetic ring 122.

[0097] The current-sharing magnetic ring 122 can provide a magnetic circuit, and the multiple layers of metal foil 110 can be wound on the current-sharing magnetic ring 122 through the wire 121 to form a corresponding plurality of coils. When the current of any layer of metal foil 110 changes, the current of the wire 121 connected to the metal foil 110 also changes. Due to the mutual inductance of the coil, the current change trend of each wire 121 is basically the same, so that the current change trend of each layer of metal foil 110 is basically the same, which can reduce or eliminate the problem of uneven current of the multiple layers of metal foil 110.

[0098] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0100] In addition, the term "connection" should be understood in a broad sense, for example, it can include fixed connection, detachable connection, or integral connection; it can include direct connection, indirect connection through an intermediate medium, and internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0101] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0102] Any process or method description in the flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0103] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A composite metal foil, characterized in that: include: Multiple layers of metal foil arranged in stacks or parallel configurations; A current balancing magnetic ring assembly comprises a plurality of wires and a current balancing magnetic ring, one end of each of the wires is connected to a corresponding layer of the metal foil, and the other end of each of the wires is wound around the current balancing magnetic ring.

2. The composite metal foil according to claim 1, characterized in that: The composite metal foil comprises an adhesive layer, which is arranged between two adjacent layers of the metal foil and is used to fix the relative positions of the two adjacent layers of the metal foil.

3. The composite metal foil according to claim 2, characterized in that: The adhesive layer is self-adhesive or organic silica gel.

4. The composite metal foil according to claim 1, characterized in that: The composite metal foil comprises an insulating member, which is arranged between two adjacent layers of the metal foil and is used for insulating and isolating the two adjacent layers of the metal foil.

5. The composite metal foil according to claim 4, characterized in that: The insulating member is a polyester imide paint film or an aromatic amide polymer insulating paper.

6. The composite metal foil according to claim 1, characterized in that: The composite metal foil further comprises a heat conductor, which is disposed between two adjacent layers of the metal foil and is used to transfer heat between the two adjacent layers of the metal foil.

7. The composite metal foil according to claim 6, characterized in that: The heat conducting member is a heat conducting silica gel used for fixing the relative positions of two adjacent layers of the metal foil.

8. The composite metal foil according to claim 1, characterized in that: The composite metal foil comprises a support member, which is arranged between two adjacent layers of the metal foil and is used to increase the distance between the two adjacent layers of the metal foil.

9. A magnetic element, characterized in that: The magnetic element comprises the composite metal foil according to any one of claims 1 to 8.

10. The magnetic element according to claim 9, characterized in that: The magnetic element comprises a magnetic core and a frame, wherein the magnetic core is arranged inside the frame, and the composite metal foil comprises aluminum foil and copper foil, wherein the copper foil is wound outside the frame, and the aluminum foil is wound outside the copper foil.

11. The magnetic element according to claim 9, characterized in that: The magnetic element comprises a magnetic core and a frame, wherein the magnetic core is arranged inside the frame, and the composite metal foil is wound outside the frame to form a multi-turn coil winding, and two adjacent layers of metal foil are used to form different turns of the coil winding.

12. The magnetic element according to claim 11, characterized in that: The composite metal foil includes multiple layers of primary metal foil and multiple layers of secondary metal foil. The primary metal foil and the secondary metal foil are alternately wound on the outside of the skeleton. The multiple layers of the primary metal foil are used to form the primary coil winding of the magnetic element, and the multiple layers of the secondary metal foil are used to form the secondary coil winding of the magnetic element.

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