Coil Element

Abstract

In an embodiment a coil element includes a first core element and a first winding body arranged around a winding carrier part of the first core element with a winding axis, wherein the first winding body includes a first film conductor element and the first film conductor element includes a plurality of conductor films stacked on top of each other along a stacking direction and arranged electrically insulated from each other, wherein the stacking direction is parallel to the winding axis, and wherein the first core element includes a plurality of windings of the first film conductor element arranged in a spiral around the winding axis.

Claims

1.-16. (canceled)

17. A coil element comprising: a first core element; and a first winding body arranged around a winding carrier part of the first core element with a winding axis, wherein the first winding body comprises a first film conductor element and the first film conductor element comprises a plurality of conductor films stacked on top of each other along a stacking direction and arranged electrically insulated from each other, wherein the stacking direction is parallel to the winding axis, and wherein the first winding body comprises a plurality of windings of the first film conductor element arranged in a spiral around the winding axis.

18. The coil element according to claim 17, further comprising an electrically insulating material arranged in the stacking direction between the conductor films and comprising a smaller thickness along the stacking direction than the conductor films.

19. The coil element according to claim 17, wherein each conductor film comprises a metallic tape.

20. The coil element according to claim 17, wherein the stacked conductor films of the first film conductor element are interconnected in parallel.

21. The coil element according to claim 17, further comprising a magnetic material arranged between windings of the first winding element.

22. The coil element according to claim 21, wherein the magnetic material comprises a magnetic permeability which is smaller than or equal to a magnetic permeability of the first core element.

23. The coil element according to claim 21, wherein the magnetic material comprises a magnetic permeability of greater than or equal to 10 and less than or equal to 100.

24. The coil element according to claim 21, wherein the magnetic material comprises a height along the stacking direction that is greater than a height of the first film conductor element along the stacking direction.

25. The coil element according to claim 21, wherein the magnetic material is formed by a magnetic tape wound around the winding carrier part together with the first film conductor element.

26. The coil element according to claim 21, wherein the first film conductor element is embedded in the magnetic material.

27. The coil element according to claim 26, wherein the first film conductor element comprises side surfaces parallel to the stacking direction and the magnetic material is located at side surfaces of the first film conductor element.

28. The coil element according to claim 21, wherein the first core element comprises a ridge-shaped part forming the magnetic material arranged between the windings of the first film conductor element.

29. The coil element according to claim 17, wherein the first core element comprises a cup core or an E core.

30. The coil element according to claim 17, wherein the coil element comprises a second core element and a second winding body, and wherein the first and second winding bodies are connected in series with each other.

31. The coil element according to claim 30, wherein the second core element with the second winding body is arranged mirror-symmetrically on the first core element with the first winding body.

32. The coil element according to claim 30, wherein the first and second core elements are identical and the first and second winding bodies are identical.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages, advantageous embodiments and further developments are revealed by the embodiments described below in connection with the figures, in which:

[0021] FIGS. 1A-1C show schematic illustrations of a coil element according to an exemplary embodiment;

[0022] FIG. 2 shows a schematic illustration of a coil element according to a further exemplary embodiment;

[0023] FIGS. 3A and 3B show schematic illustrations of a coil element according to a further exemplary embodiment;

[0024] FIGS. 4A and 4B show schematic illustrations of a coil element according to a further exemplary embodiment;

[0025] FIG. 5 shows a schematic illustration of a section of a film conductor element of a coil element according to a further exemplary embodiment; and

[0026] FIG. 6 shows a schematic illustration of a section of a coil element according to a further exemplary embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0027] In the embodiments and figures, identical, similar or identically acting elements are provided in each case with the same reference numerals. The elements illustrated and their size ratios to one another should not be regarded as being to scale, but rather individual elements, such as for example layers, components, devices and regions, may have been made exaggeratedly large to illustrate them better and/or to aid comprehension.

[0028] In connection with FIGS. 1A to 1C a coil element 100 is shown with a core element 1 and a winding body 2. With respect to the following exemplary embodiments, the core element 1 and the winding body 2 are referred to as the first core element 1 and the first winding body 2, respectively. In FIG. 1A, a schematic sectional view of the coil element 100 is shown. The first winding body 2 comprises a first film conductor element 21. In FIG. 1B, a schematic view of a section of the first film conductor element 21 is shown. In FIG. 1C, a schematic illustration of a section of the first film conductor element 21 is shown according to an alternative exemplary embodiment. Unless otherwise specified, the following description refers equally to FIGS. 1A to 1C.

[0029] The first film conductor element 21 comprises a plurality of conductor films 22 stacked on top of each other, as can be seen in FIGS. 1B and 1C. In particular, the first film conductor element 21 may comprise at least 10 or preferably at least 20 or particularly preferably at least 50 conductor films 22. In a particularly preferred exemplary embodiment, the first film conductor element 21 comprises, for example, 100 stacked conductor films 22. The arrangement direction of the conductor films on top of each other is referred to as the stacking direction S and is indicated in FIGS. 1A to 1C, respectively.

[0030] Each of the conductor films 22 of the first film conductor element 21 is formed in a tape shape and comprises a width B perpendicular to the stacking direction S and a thickness D parallel to the stacking direction S, as indicated in FIG. 1B. Further, each of the conductor films 22 comprises a length along a longitudinal direction perpendicular to the width B and the thickness D, which respectively indicates the greatest extent of the conductor films 22. The length is thus greater than the width B, which in turn is greater than the thickness D. In the exemplary embodiment shown, each of the conductor films 22 is formed by a copper tape. Alternatively, other metallic materials are also possible.

[0031] The conductor films 22 of the first film conductor element 21 are arranged electrically insulated from one another. For this purpose, an electrically insulating material 23 is arranged between the conductor films 22, which particularly preferably comprises a thickness d which is smaller than the thickness D of the conductor films 22. For example, D/d≤10. The electrically insulating material 23 can, for example, be formed by electrically insulating plastic film tapes arranged alternately with the conductor films 22 one above the other.

[0032] For manufacturing the first film conductor element 21, copper films and plastic films can, for example, be alternately stacked on top of each other and fixated or laminated and, if necessary, cut into a desired shape. Furthermore, it is also possible, for example, to roll up a copper film and a plastic film with a number of windings corresponding to the desired number of layers on a roll, to fix them and to cut them in such a way that a flat stack can be produced when removing them from the roll. Three-dimensional printing processes are also conceivable. As indicated in FIG. 1C, the conductor films 22 can also each be coated, for example, with an electrically insulating plastic varnish as an electrically insulating material 23 and stacked one on top of the other.

[0033] The first film conductor element 21 comprises a height H, indicated in FIG. 1A, which is at least equal to the sum of the thicknesses D of all conductor films 22 and, in particular, the sum of the thicknesses D and d of the conductor films 22 and the electrically insulating material 23 therebetween. For example, in the case of an electrically insulating varnish as the electrically insulating material 23, the thickness d of the electrically insulating material may also be negligible compared to the thickness D of the conductor films 22. The width B of the first film conductor element 21 substantially corresponds to the width B of the conductor films 22. As indicated in FIGS. 1B and 1C, the first film conductor element 21 is bounded in the width direction by side surfaces 24, which may be covered with the electrically insulating material 23, depending on the manufacturing process, as indicated in FIG. 1C.

[0034] For example, 100 conductor films 22 can be used for the first film conductor element 21, each of which comprises a thickness of 150 μm and a width in the range of 1 to 2 mm in the first film conductor element 21, so that in this case the first film conductor element 21 can have, for example, a height of about 15 mm and an aforementioned width. Alternatively, larger and smaller dimensions are also possible, depending on the application. In particular, the described coil element may distinguish itself by the fact that the dimensions of the individual components are easily scalable and not restricted to specific sizes.

[0035] The stacked conductor films 22 of the first film conductor element 21 are interconnected in parallel with each other at the beginning and at the end in the longitudinal direction, wherein such interconnections as well as electrical connections are not shown for the sake of clarity.

[0036] The first core element 1 may comprise or be, for example, a cup core or an E-core. Alternatively, other or related core forms are also possible, for example a planar core or an ER core. In addition, the coil element 100 may comprise, for example, a further core element, which may be, for example, an I-core or disc-shaped core element, and which may be arranged on the first core element 1 such that it may form a magnetic circuit together with the first core element 1.

[0037] For example, the first core element 1 comprises a ferrite-based magnetic material. Furthermore, other materials, for example based on one or more selected from Ni—Fe—Mo, Ni—Fe, Fe—Si—Al and Fe—Si, are also possible. For example, the core element 1 comprises or is made of the material Sendust or Mega Flux described in the general part.

[0038] The first core element 1 comprises a winding carrier part 11. The first winding body 2 is arranged around the winding carrier part 11 and comprises a winding axis 20 indicated in FIG. 1A. The first film conductor element 21 is wound around the winding carrier part 11 of the first core element 1 in the manner of a spiral, thereby defining the winding axis 20. The winding carrier part 11 is thus arranged in the center of the spirally wound first film conductor element 21, and may also be referred to as a so-called slug of the core element 1. A direction along the winding axis 20 may also be referred to as a vertical axis. Directions perpendicular to the winding axis 20 may also be referred to as horizontal directions. Thus, in a section corresponding to a horizontal sectional plane through the first winding body 2, it would be seen that the first winding body 2 is arranged in the manner of a spiral with a plurality of windings of the first film conductor element 21 around the winding axis 20. Accordingly, the first winding body 2 comprises a plurality of windings of the first film conductor element 21 around the winding axis 20 in a spiral fashion. Each turn of the first film conductor element 21 around the winding carrier part 11 forms a winding. In the sectional view of FIG. 1A, the adjacent windings are shown spaced apart for clarity. Alternatively, the windings can also be arranged directly next to each other. This may be possible, in particular, if the side surfaces 24 of the first film conductor element 21 are covered with an electrically insulating material. Alternatively, it may also be possible to wind an electrically insulating film around the winding carrier part 11 together with the first film conductor element 21 so that adjacent windings are electrically separated from each other by the electrically insulating film.

[0039] As can be seen in FIG. 1A, the stacking direction S is parallel to the winding axis 20. In other words, the conductor films 22 are arranged one above the other along the direction of the winding axis 20 and thus in a vertical direction. Thus, the direction specified by the thickness D of the conductor films 22 is parallel to the winding axis 20. The conductor films 22 extend spirally around the winding axis 20 in horizontal planes that are parallel to the length and the width of the conductor films 22.

[0040] The first core element 1 further comprises an edge portion 12 which, together with the winding carrier part 11, defines a winding chamber 13 in which the first winding body 2 is arranged. Depending on the design of the first core element 1, for example as a cup core or E-core, the edge portion 12 can completely or at least partially surround the first winding body 2 in a horizontal plane. Due to the described embodiment and arrangement of the first film conductor element 21, this can be placed up to the corners of the winding chamber 13 provided for the first winding body 2 in the first core element 1.

[0041] As further indicated in FIG. 1A, the winding carrier part 11 may comprise a greater height in the vertical direction, i.e., in a direction parallel to the winding axis 20, than the first film conductor element 21 and thus than the first winding body 2. Further, the winding carrier part 11 may comprise a smaller height in the vertical direction than the edge portion 12. Thus, if the first core element 1 is covered by another core element, an air gap can be formed in the vertical direction above the winding carrier part 11. By leaving the region of the winding carrier part 11 adjacent to the air gap free, it may be possible, depending on the geometry, to reduce or even avoid the stray field at the air gap.

[0042] FIG. 2 shows another exemplary embodiment for a coil element 100, which comprises a second core element 1′ and a second winding body 2′ in addition to the first core element 1 and the first winding body 2. The features described above for the first core element 1 and the first winding body 2 apply equally to the second core element 1′ and the second winding body 2′. Particularly preferably, the first and second core elements 1, 1′ can be embodied similarly as shown. Accordingly, the second winding body 2′ comprises a second film conductor element 21′ formed like the first film conductor element 21. The first and second winding bodies 2, 2′ and thus the first and second film conductor elements 21, 21′ are preferably connected in series with one another.

[0043] The second core element 1′ with the second winding body 2′ is arranged on the first core element 1 with the first winding body 2 such that the first and second winding bodies 2, 2′ are arranged facing each other. As can be easily seen, the second core element 1′ with the second winding body 2′ is arranged mirror-symmetrically along the stacking direction S on the first core element 1 with the first winding body 2, wherein the edge parts 12, 12′ of the first and second core elements 1, 1′ can rest on each other.

[0044] An air gap 4 is formed between the winding carrier parts 11, 11′ of the first and second core elements 1, 1′ due to the lower height of the winding carrier parts 11, 11′ compared to the respective edge parts 12, 12′. Due to the fact that the winding bodies 2, 2′ further comprise a lower height than the winding carrier parts 11, 11′, each winding carrier part 11, 11′ has a region left free. As described in connection with the previous exemplary embodiment, by leaving free the region of the winding carrier parts 11, 11′ adjacent to the air gap 4, respectively, which may also be referred to as the center region, the stray field at the air gap 4 can be reduced or even avoided.

[0045] In FIGS. 3A and 3B and in FIGS. 4A and 4B, respectively, in a sectional view and a three-dimensional view, which is cut open in FIG. 4B for better comprehensibility, further exemplary embodiments for the coil element 100 are shown, which represent modifications of the exemplary embodiments shown in connection with FIGS. 1A to 1C and with FIG. 2. Purely by way of example, the core elements in FIGS. 3A to 4B are cup cores. Alternatively, as described above, other core shapes are also possible.

[0046] Compared to the previous exemplary embodiments, in the exemplary embodiments shown in FIGS. 3A and 3B and FIGS. 4A and 4B, a magnetic material 3 is arranged between windings of the first winding body 2 and the first and second winding bodies 2, 2′, respectively. Particularly preferably, as shown, the magnetic material 3 is arranged between directly adjacent windings. Preferably, the magnetic material 3 comprises a magnetic permeability that is smaller than or equal to a magnetic permeability of the first core element 1 or of the first and second core elements 1, 1′, respectively. Particularly preferably, the magnetic material 3 comprises a magnetic permeability of greater than or equal to 10 and less than or equal to 100.

[0047] In the exemplary embodiments shown in FIGS. 3A to 4B, the magnetic material 3 is formed in each case by a magnetic tape 31, which may also be referred to as a magnetic tape, which is wound around the respective winding carrier part 11, 11′ together with the respective film conductor element 21, 21′. The magnetic tape 31 may comprise, for example, a plastic material forming a plastic carrier in and/or on which ferrite and/or iron-based particles, powder grains and/or nanocrystallites are embedded or arranged.

[0048] In the vertical direction, i.e. along the stacking direction S, the magnetic material 3 comprises a height which is greater than or equal to the height of the respective film conductor element 21, 21′. Particularly preferably, the magnetic material 3 comprises a height in the vertical direction which is greater than the height of the respective film conductor element 21, 21′ in the vertical direction, so that the magnetic material 3 is higher in the vertical direction than the respective film conductor element 21, 21′ and thus protrudes above the film conductor element 21, 21′ in the vertical direction.

[0049] By using the magnetic material 3 parallel to the windings of the respective film conductor element 21, 21′, the field guidance can be improved. It could be shown by simulations that, for example, the coil element 100 shown in FIG. 4 comprises significantly lower AC winding losses compared to a conventional coil design with corresponding core elements and dimensions using common strand-based winding bodies which do not allow the use of magnetic material between the windings.

[0050] As indicated in FIGS. 3B and 4B, a portion of each of a film conductor element 21, 21′ that is led outwardly through an opening in the respective core element 1, 1′ may form an electrical connection. Alternatively, other electrical connections may be provided.

[0051] As an alternative to a magnetic tape as magnetic material 3, the first film conductor element 21 and the first and second film conductor elements 21, 21′, respectively, may be embedded in the magnetic material 3. As shown in FIG. 5 by way of example using a section of the first film conductor element 21, a magnetic varnish 32, for example formed by a plastic material in which ferrite and/or iron-based particles, powder grains and/or nanocrystallites are contained, can be used for this purpose. The magnetic material 3 may preferably be applied for this purpose to the side surfaces 24 prior to winding onto the winding carrier part of the core element.

[0052] As shown in a section of the first core element 1 with the first winding body 2 in FIG. 6, the first core element 1 according to a further exemplary embodiment may also comprise a ridge-shaped portion 14 forming the magnetic material 3, which is arranged between the windings of the first film conductor element 21. In other words, the first core element 1 may comprise a channel extending spirally around the winding carrier part 11, in which the first film conductor element 21 is preferably arranged completely recessed. In the case of a coil element 100 with a second core element 1′, as shown in FIGS. 4A and 4B, the second core element 1′ may comprise a corresponding ridge-shaped portion and thus a corresponding spiral-shaped channel in which the second film conductor element is arranged.

[0053] The features and embodiments described in connection with the figures may be combined with each other according to further exemplary embodiments, although not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures may alternatively or additionally comprise further features according to the description in the general part.

[0054] The invention is not limited to the exemplary embodiments by the description based thereon. Rather, the invention encompasses any new feature as well as any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or combination itself is not explicitly specified in the patent claims or exemplary embodiments.