Shielding film and method for producing a shielding film

1. A shielding film for a device with components for wireless charging, comprising: a plurality of stacked layers, wherein the layers each have a plurality of strips of a nanocrystalline soft magnetic alloy arranged on an adhesive layer, the nanocrystalline soft magnetic alloy having a round hysteresis loop and the strips of adjacent layers being offset with respect to one another, and wherein the nanocrystalline soft magnetic alloy has a hysteresis loop with a ratio of remanence induction, Br, to saturation induction, Bs, Br/Bs, in the closed magnetic circuit from 30% to 100%.

2. The shielding film as set forth in claim 1 , wherein the soft magnetic alloy consists of a composition of Fe100-a-b-c-x-y-zCuaMbTcSixZz and up to 0.5 atom % contaminants, where M is one or more of the group consisting of Nb, Mo and Ta; T is one or more elements selected from the group consisting of V, Cr, Co and Ni; and Z is one or more elements selected from the group consisting of C, P and Ge; and wherein 0.5 atom % <a<1.5 atom %, 2 atom % <b<4 atom %, 0 atom % <c<5 atom %, 12 atom % <x<18 atom %, 5 atom % <y<12 atom % and 0 atom % <z<2 atom %.

3. The shielding film as set forth in claim 1 , wherein the nanocrystalline soft magnetic alloy is Fe 73.8 Nb 3 Cu 1 Si 15.6 B 6.6 .

4. The shielding film as set forth in claim 1 , wherein the shielding film is capable of being wound around surfaces and/or adapted to surfaces.

5. The shielding film as set forth in claim 1 , wherein the strips have the structure of a film or of a band.

6. The shielding film as set forth in claim 1 , wherein the nanocrystalline soft magnetic alloy has a frequency-dependent permeability μ=μ′+iμ″ and a quality factor Q(f)=μ′+μ″, such that the maximum quality factor Qmax is >22.

7. The shielding film as set forth in claim 1 , wherein the strips have a thickness d, where d <20 μm.

8. The shielding film as set forth in claim 1 , wherein adjacent strips of a layer are spaced apart from one another by a gap of 0.1 mm to 0.3 mm.

9. The shielding film as set forth in claim 1 , wherein an adhesive film is arranged between the strips of adjacent layers.

10. The shielding film as set forth in claim 1 , wherein strips of adjacent layers are arranged parallel to one another.

11. The shielding film as set forth in claim 1 , wherein the strips of adjacent layers are arranged transverse to one another.

12. A shielding film for a device with components for wireless charging, comprising: a plurality of stacked layers, wherein the layers each have a plurality of strips of a nanocrystalline soft magnetic alloy arranged on an adhesive layer, the nanocrystalline soft magnetic alloy having a round hysteresis loop and the strips of adjacent layers being offset with respect to one another, and wherein the strips of adjacent layers are interwoven.

13. An object comprising a battery, a receiver coil for wirelessly receiving power, and a shielding film as set forth in claim 1 .

14. The object as set forth in claim 13 , wherein the shielding film is arranged between the battery and the receiver coil.

15. The object as set forth in claim 13 , wherein the object further comprises a housing with an inner surface, and wherein the shielding film is arranged on the inner surface.

16. An object comprising a transmitter coil for wirelessly sending power to a receiver coil, and a shielding film as set forth in claim 1 .

17. The object as set forth in claim 16 , wherein the shielding film is arranged on the transmitter coil.

18. The object as set forth in claim 16 , wherein the object further comprises a housing with an inner surface, and wherein the shielding film is arranged on the inner surface.

19. A method for manufacturing a shielding film, comprising the following:

providing a band of an amorphous soft magnetic alloy

thermally treating the band at a temperature of 500° C. to 600° C. for 1 minute to 1 hour under an N2- or H2-containing atmosphere and under the Earth's magnetic field, thereby creating a nanocrystalline soft magnetic band with a round hysteresis loop,

applying an adhesive layer to at least one side of the band, thus creating a layer,

structuring of the band in order to produce several strips from the band,

stacking of at least two layers on one another, so that the strips of adjacent layers are offset with respect to one another, thus creating a shielding film according to claim 1 .

20. The method as set forth in claim 19 , wherein the band is first applied to a substrate, then thermally treated, after which an adhesive film is applied to the band and, finally, the band is structured in order to produce several strips on the adhesive film.

21. The method as set forth in claim 19 , wherein the amorphous band is structured in order to produce several strips, then thermally treated, after which an adhesive film is applied to the strips.

22. The method as set forth in claim 19 , wherein amorphous bands are interwoven and then thermally treated.

23. The method as set forth in claim 19 , wherein a one-sided or double- sided adhesive film, heat-sealable film or powdered hot adhesive is used as the adhesive layer.

24. The method as set forth in claim 19 , wherein the thermal treatment is done in a continuous pass.

25. The method as set forth in claim 19 , wherein the band is cut mechanically or chemically into several strips.

26. The method as set forth in claim 19 , wherein the band is cut mechanically with rolling scissors into several strips.

27. The method as set forth in claim 19 , wherein the band is pulled under tensile force over a sharp edge in order to divide the band into several parts.

28. The method as set forth in claim 19 , wherein shielding parts are punched or cut from the band with an amorphous alloy or from the band with a nanocrystalline alloy.

29. A method of shielding an object with components for wireless charging comprising applying to the object a shielding film as set forth in claim 1 .

30. A method of shielding an object with components to be shielded comprising applying to the object a shielding film as set forth in claim 1 .

31. The method as set forth in claim 30 , wherein the components to be shielded include one or more of the group consisting of electronic components, cables, sensor regions, and hollow spaces.