Summary

In some aspects of the present description, a magnetic film assembly is provided, including a first magnetic film having a plurality of spaced apart soft magnetic tiles arranged along orthogonal first and second in-plane directions of the first magnetic film, the spaced apart magnetic tiles defining a plurality of gaps therebetween; and a second magnetic film disposed on, and substantially co-extensive with, the first magnetic film, such that in a plan view, the second magnetic film substantially covers the plurality of the gaps.

In some aspects of the present description, a hybrid magnetic film assembly is provided, including a first magnetic film defining a plurality of channels, the channels reducing an effective permeability of the first magnetic film; and a second magnetic film disposed on, and substantially co-extensive with, the first magnetic film, the hybrid magnetic film assembly having an effective magnetic permeability greater than the effective permeability of the first magnetic film.

In some aspects of the present description, a hybrid magnetic film assembly is provided, including a plurality of substantially coextensive magnetic films stacked on top of each other, each magnetic film defining a plurality of channels defining a plurality of islands therebetween, the islands in the magnetic films offset relative to each other so that in a plan view, the channels of each magnetic film are substantially completely covered by a combination of one or more islands of the other magnetic films.

In some aspects of the present description, a magnetic film assembly is provided, including at least two substantially coplanar soft magnetic segments, each pair of adjacent soft magnetic segments separated by a gap configured to generate a demagnetization field, a flexible magnetic film bridging across the gap and reducing the demagnetization field.

In some aspects of the present description, a magnetic film assembly is provided, including at least two substantially coplanar soft magnetic portions, each pair of adjacent soft magnetic portions defining a magnetic reluctance therebetween, a magnetic material disposed at least between the adjacent soft magnetic portions and reducing the magnetic reluctance.

In some aspects of the present description, a hybrid magnetic film is provided, including a regular array of spaced apart magnetic islands arranged along orthogonal first and second in-plane directions of the hybrid magnetic film, the magnetic islands defining a regular array of interconnected through-channels therebetween, the through-channels at least partially filled with a magnetically permeable material.

In some aspects of the present description, a wireless power transfer system is provided, the wireless power transfer system configured to operate at an operating frequency, the system including: a first magnetic film having a first absorption at a first frequency that is a harmonic of the operating frequency and comprising a plurality of spaced apart magnetic tiles defining a plurality of gaps therebetween; and a second magnetic film disposed on the first magnetic film and at least covering the plurality of gaps, the second magnetic film having a second absorption at the first frequency greater than the first absorption.

In some aspects of the present description, a system for a wireless power transmission is provided, including a power receiving assembly having a first magnetic film assembly disposed between a first metal plate and a power receiving antenna; and a power transmitting assembly facing the power receiving assembly and comprising a second magnetic film assembly disposed between a second metal plate and a power transmitting antenna, the power receiving and transmitting antennas facing, and substantially aligned with, one another, such that when energized, the power transmitting antenna wirelessly transmits power to the power receiving antenna, wherein at least one of the first and second magnetic film assemblies includes a plurality of spaced apart magnetic tiles defining a plurality of gaps therebetween; and a magnetic film disposed on the magnetic tiles and covering the gaps.

Brief Description of the Drawings

FIG. 1 is a side, cutaway view of a magnetic film assembly, in accordance with an embodiment of the present description;

FIG. 2 is a side, cutaway view of a magnetic film assembly, in accordance with an alternate embodiment of the present description;

FIG. 3 is a side, cutaway view of a hybrid magnetic film, in accordance with an alternate embodiment of the present description;

FIG. 4 is a side, cutaway view of a system for a wireless power transmission, in accordance with an alternate embodiment of the present description;

FIG. 5 is a perspective view of a magnetic film featuring magnetic tiles disposed on a tray, in accordance with an embodiment of the present description;

FIG. 6 is a side, cutaway view of a stacked magnetic film assembly, in accordance with an embodiment of the present description;

FIG. 7 is a top view of a hybrid multilayer magnetic film, in accordance with an embodiment of the present description; and FIG. 8 is a side, cutaway view of a magnetic film assembly with two or more layers of magnetic tiles, in accordance with an embodiment of the present description.

Detailed Description

In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense.

The use of wireless charging (e.g., when energy is transferred from a transmitting coil to an adjacent receiving coil) is rapidly increasing. In some instances, wireless charging may allow the use of smaller batteries and increased convenience in applications (e.g., such as the charging of mobile devices, electrical vehicles, etc.) as additional charging stations/sources are installed. Increasing the efficiencies (i.e., reducing losses during the transfer of energy) involved in wireless charging applications may further advance the technology, leading to widespread adoption.

A wireless charging system, such as a wireless power transfer (WPT) system for electric vehicles, typically consists of two coils. One coil is attached to ground (the transmitting, or Tx, coil) and transmits power to the coil attached to the electric vehicle (the receiving, or Rx, coil).

The Tx coil is fed by a device called an inverter. The inverter converts direct current (DC) into alternating current (AC). The AC current produces electromagnetic fields that couple the Tx coil to the Rx coil, AC current is consequently induced on the Rx coil. The Rx AC current is then fed through a full wave rectifier to convert it back to DC for use by the vehicle’s battery charging system.

To get practical efficiencies for an electric vehicle WPT system, the Tx and Rx currents should be oscillating near their resonant frequencies. To do this at practical frequencies, impedance matching networks are coupled to the Tx and Rx coils. In some embodiments, additional materials may be added to a WPT system to increase power and efficiency. For example, layers of ferrite material may be used to confine the electromagnetic fields generated to the volume between the two coils, and to isolate the fields such that they do not interact with lossy materials, such as the metallic car body.

Using layers of ferrite material can also have a concentrating effect that increases the power transferred between the Tx and Rx coils. In some cases, ferrite tiles are placed as a layer adjacent each of the Tx and Rx coils. However, ferrite tiles are often hard, brittle, and difficult to manufacture at the lower thicknesses and large surface areas needed in a WPT system. Another potential issue with using ferrite tiles is that tile-to-tile gaps (e.g., air gaps between adjacent tiles) can cause performance issues. That is, the effective permeability decreases as the spacing increases between tiles, in a phenomenon known as demagnetization. Gap size must be carefully controlled and minimized to maintain performance. This requires precise machining of each of the six surfaces of the rectangular tile to ensure a tight fit during installation.

According to some aspects of the present invention, a thin, magnetic film (e.g., a flexible sheet of a flux field directional material, or FFDM) may be applied over a matrix of ferrite tiles to reduce the demagnetization effect caused by tile-to-tile gaps, and accordingly increases the effective permeability of the WPT system.

According to some aspects of the present description, a magnetic film assembly may include a first magnetic film having a plurality of spaced-apart, soft magnetic tiles (e.g., ferrite tiles) arranged along orthogonal first and second in-plane directions of the first magnetic film and defining a plurality of gaps therebetween, and a second magnetic film disposed on, and substantially co-extensive with, the first magnetic film. In some embodiments, the second magnetic film is disposed on the first magnetic film such that it substantially covers the plurality of gaps (i.e., tile-to-tile gaps) in the first magnetic film.

In some embodiments, the magnetic tiles are ferrite tiles. In some embodiments, the ferrite tiles may include at least one of a manganese-zinc ferrite and a nickel-zinc ferrite. In some embodiments, the magnetic tiles include magnetically conductive fillers dispersed in a binder material. In some embodiments, the magnetic tiles may further include thermally-loaded fillers dispersed in a binder material. In some embodiments, the magnetic tiles may include a crystalline, microcrystalline, or amorphous alloy. In some embodiments, the crystalline, microcrystalline, or amorphous alloy may include iron and one or more of silicon, aluminum, boron, niobium, copper, cobalt, nickel, and molybdenum. In some embodiments, the magnetic tiles may be irregularly shaped. For example, the magnetic tiles may be segments of material (e.g., “islands” of material) formed by “cracking” a sheet of magnetic material (e.g., a sheet of nano-crystalline and/or composite material), and the gaps between tiles may be the spaces between adjacent segments (i.e., the cracks between segments caused by the cracking process.) The term “tiles” is not intended to limit the shape or regularity of the segments, nor the method of creating the segments, in any way.

In some embodiments, the first magnetic film may include two or more layers of stacked magnetic tiles. In some embodiments, the two or more layers of stacked magnetic tiles may be stacked such that the tiles in one layer are aligned with the tiles of an adjacent layer. In some embodiments, a thin dielectric film may be disposed between two adjacent layers of magnetic tiles.

In some embodiments, the gaps between magnetic tiles may be filled with a substantially magnetically-insulative material. In some embodiments, the magnetically-insulative material may be air. In some embodiments, the magnetically-insulative material may include a thermally conductive material. In some embodiments, magnetically-insulative material may include a bonding material bonding the magnetic tiles to each other.

For the purposes of this specification, the terms “magnetically insulative” and “magnetically conductive” shall be defined as follows. When higher (magnetic) permeability materials and lower permeability materials are used together (e.g., in a coil), magnetic field lines tend to be more concentrated in the higher permeability material and less concentrated in the lower permeability material, so high permeability (e.g., significantly higher than vacuum permeability) materials can be described as “magnetically conductive” and low permeability (e.g., comparable to vacuum permeability) materials can be described as “magnetically insulative.”

A magnetically conductive material or layer is a material or layer having a relative permeability of at least 2, and a magnetically insulative material or layer is a material or layer having a relative permeability of no more than 1.5. In some embodiments, a magnetically conductive layer has a relative permeability of greater than 2, or greater than 10, or greater than 100. In some embodiments, a magnetically insulative layer has a relative permeability of less than 1.5, or less than 1.4, or less than 1.2, or less than 1.1, or less than 1.05. In some embodiments, a magnetically insulative layer has a relative permeability in a range of 0.99 to 1.05, for example. In some embodiments, a coil includes a plurality of loops where each loop includes a magnetically insulative layer and a magnetically conductive layer. In some embodiments, a relative permeability of the magnetically conductive layer is at least 10 times, or at least 100 times a relative permeability of the magnetically insulative layer. The relative permeability refers to the real part of the complex relative permeability, unless indicated otherwise.

Magnetic properties (e.g., low- or high-permeability) as defined and used herein refer to the respective property evaluated at low frequencies (e.g., about 1 kHz or less) or evaluated statically (e.g., direct current), unless otherwise indicated, and determined at 20 degrees C, unless otherwise indicated.

In some embodiments, the average gap size of the gaps between magnetic tiles may be in a range between about 0.5 millimeters (mm) and about 50 mm, or between about 1 mm and about 25 mm, or between about 1 mm and about 10 mm, or between about 1mm and about 3 mm.

In some embodiments, the average thickness of the spaced-apart soft magnetic tiles (tl) and the average thickness of the second magnetic film (t2) are such that tl is greater than or equal to 2 times t2.

In some embodiments, the magnetic film assembly may further include a support layer or substrate which provides support to the plurality of spaced-apart magnetic tiles. In some embodiments, the magnetic film assembly may further include a third magnetic film disposed on, and substantially co-extensive with, the first magnetic film, such that the first magnetic film is disposed between the second and third magnetic fdms. In some embodiments, the third magnetic fdm may substantially cover the plurality of gaps between magnetic tiles. In some embodiments, two or more of the magnetic film assemblies may be stacked on top of each other to create a magnetic film stack (or “magnetic stack.”)

In some embodiments, the second magnetic film may be a multilayer film including an inner soft magnetic layer, a protective polyester cover film (e.g., polyethylene terephthalate, or PET), and a pressure sensitive adhesive. One example of such a material is the 3M™ Flux Field Directional Material (FFDM) manufactured by the 3M Corporation. The FFDM materials (also sometimes referred to as “magnetic isolators”) are, in some embodiments, composed of microcrystalline (which, in some embodiments, may include nano-crystalline) ribbon and composites. These materials are flexible, readily manufacturable in various thicknesses, and can be manufactured to cover large surface areas.

In some embodiments, the magnetic film assembly may further include a tray having a plurality of compartments, with each compartment having at least one sidewall, such that each of the magnetic tiles of the first magnetic film are disposed within a different compartment.

According to some aspects of the present description, a hybrid magnetic film may include a first magnetic film defining a plurality of channels, the channels reducing an effective permeability of the first magnetic film; and a second magnetic film disposed on, and substantially co-extensive with, the first magnetic film. In some embodiments, the hybrid magnetic film assembly may have an effective magnetic permeability greater than the effective permeability of the first magnetic film. In some embodiments, the plurality of channels may include a plurality of interconnected channels. In some embodiments, the plurality of channels may include a plurality of through-channels (i.e., channels which pass all the way through the thickness of the first magnetic film, such that the first magnetic film is divided into smaller subsections separated by gaps). Stated another way, the plurality of through-channels may define an array of spaced apart self-supporting magnetic segments therebetween. In some embodiments, the self- supporting magnetic segments may form a two-dimensional regular array or grid.

According to some aspects of the present description, a hybrid magnetic film assembly may include a plurality of substantially coextensive magnetic films stacked on top of each other, each magnetic film defining a plurality of channels or gaps defining a plurality of islands therebetween. In some embodiments, the islands in each of the magnetic films may be offset relative to each other so that in a plan view, the channels or gaps of each magnetic film are substantially completely covered by a combination of one or more islands of the other magnetic films. In some embodiments, the hybrid magnetic film assembly may include two or more layers of magnetic tiles (e.g., ferrite tiles) where the two or more layers of magnetic tiles are intentionally misaligned such that the tiles of one layer substantially cover the channels or gaps in at least one other layer.

According to some aspects of the present description, a magnetic fdm assembly may include at least two substantially coplanar soft magnetic segments, each pair of adjacent soft magnetic segments separated by a gap configured to generate a demagnetization field, a flexible magnetic film bridging across the gap and reducing the demagnetization field. In some embodiments, the flexible magnetic film may be disposed on a substrate, the substrate disposed between the flexible magnetic film and the substantially coplanar soft magnetic segments.

According to some aspects of the present description, a magnetic film assembly may include at least two substantially coplanar soft magnetic portions, each pair of adjacent soft magnetic portions defining a magnetic reluctance therebetween, a magnetic material disposed at least between the adjacent soft magnetic portions and reducing the magnetic reluctance. In some embodiments, each pair of adjacent soft magnetic portions may define a substantially magnetically-insulative region therebetween. In some embodiments, the substantially magnetically-insulative region may define the magnetic reluctance. In some embodiments, the magnetic material at least covers the substantially magnetically-insulative region. In some embodiments, the substantially magnetically insulative region may include a through- channel, and the magnetic material at least covers the through-channel. In some embodiments, the magnetic material may at least partially fill the through-channel.

According to some aspects of the present description, a hybrid magnetic film may include a regular array of spaced apart magnetic islands arranged along orthogonal first and second in plane directions (e.g., along a length and width) of the hybrid magnetic film. In some embodiments, the magnetic islands may define a regular array of interconnected through-channels (e.g., spaces between islands which pass all the way through the thickness direction of the film) therebetween. In some embodiments, the through-channels may at least partially be filled with a magnetically permeable material. In some embodiments, the magnetically permeable material may include magnetic particles including one or more of iron, nickel, chrome, and ferrite. In some embodiments, the magnetically permeable material may include thermally conductive particles.

According to some aspects of the present description, a wireless power transfer system configured to operate at an operating frequency may include a first magnetic film having a first absorption at a first frequency that is a harmonic of the operating frequency and including a plurality of spaced apart magnetic tiles defining a plurality of gaps therebetween; and a second magnetic film disposed on the first magnetic film and at least covering the plurality of gaps, the second magnetic film having a second absorption at the first frequency greater than the first absorption. In some embodiments, the operating frequency may be in a range between about 79 kkHz and about 100 kkHz. In some embodiments, the wireless power transfer system may include one or more additional magnetic films disposed on the first magnetic film, each additional magnetic film having a greater absorption than the first magnetic film at one or more harmonic frequencies of the operating frequency.

According to some aspects of the present description, a system for a wireless power transmission includes a power receiving assembly and a power transmitting assembly. In some embodiments, the power receiving assembly may include a first magnetic film assembly disposed between a first metal plate and a power receiving antenna. In some embodiments, the power transmitting assembly may face the power receiving assembly and include a second magnetic film assembly disposed between a second metal plate and a power transmitting antenna. In some embodiments, the power receiving and transmitting antennas may face, and be substantially aligned with, one another, such that when energized, the power transmitting antenna wirelessly transmits power to the power receiving antenna. In some embodiments, at least one of the first and second magnetic film assemblies may include a plurality of spaced apart magnetic tiles defining a plurality of gaps therebetween; and a magnetic film disposed on the magnetic tiles and covering the gaps.

Turning now to the figures, FIG. 1 is a side, cutaway view of a hybrid magnetic film assembly (e.g., such as may be used in a wireless power transfer system), according to the present description. A hybrid magnetic film assembly 100 includes a first magnetic film 10 and a second magnetic film 50. In some embodiments, magnetic film 10 may include a plurality of spaced-apart soft magnetic tiles 20 (e.g., ferrite tiles). In some embodiments, the magnetic tiles 20 may be arranged along a first in-plane direction (e.g., the x-direction indicated in FIG. 1) and a second in plane direction (e.g., the y-direction in FIG. 1). For example, magnetic tiles 20 may be arranged in a two-dimensional grid. In some embodiments, magnetic tiles 20 are arranged such that they define a plurality of gaps 30 therebetween. In some embodiments, the gaps 30 may be filled with a material 40 that is substantially magnetically insulative. In some embodiments, material 40 may be air. In some embodiments, material 40 may be a thermally conductive material. In some embodiments, material 40 may include a bonding material bonding the magnetic tiles 20 to each other.

In some embodiments, second magnetic film 50 is substantially co-extensive with first magnetic film 10. In some embodiments, second magnetic film 50 may be disposed on first magnetic film 10 such that second magnetic film 50 substantially covers gaps 30. In some embodiments, the magnetic tiles 20 have an average thickness of tl, and the second magnetic fdm 50 has an average thickness of t2, such that tl is greater than or equal to 2 times t2 (tl > 2t2).

In some embodiments, the magnetic tiles 20 of hybrid magnetic film assembly 100 may be disposed on a support layer 11 (e.g., a polymeric substrate). In some embodiments, hybrid magnetic film assembly 100 may include a third magnetic film 110, wherein the first magnetic film 10 is disposed (i.e., sandwiched) between the second magnetic film 50 and the third magnetic film 110. In some embodiments, hybrid magnetic film assembly 100 may be used in a system for wireless power transmission (e.g., a wireless charging system). An example of such a wireless power transmission system will be described in the discussion of FIG. 4.

FIG. 2 is a side, cutaway view of an alternate embodiment of a hybrid magnetic film assembly according to the present description. Hybrid magnetic film assembly 200 includes a first magnetic film 10 including at least two soft magnetic portions 20, which are substantially coplanar. Between each pair of magnetic portions 20 (i.e., in gaps 30), a magnetic reluctance 70 is defined. Magnetic reluctance, or magnetic resistance, is an opposition to the flow of magnetic flux through a given space or volume. Magnetic reluctance 70 may contribute to a phenomenon known as demagnetization of the assembly, which can decrease the effective magnetic permeability of the assembly. In some embodiments, a second magnetic film (such as second film 50 in FIG. 1) or segments of a magnetic material 80 may be disposed on magnetic film 10 between adjacent magnetic portions 20, thereby reducing magnetic reluctance 70. In some embodiments, magnetic portions 20 may be disposed on a support layer 11 (i.e., a polymeric substrate).

FIG. 3 is a side, cutaway view of an embodiment of a hybrid magnetic film according to the present description. A hybrid magnetic film 300 includes a regular array of spaced-apart magnetic islands 20 separated by gaps (e.g., through-channels) 30. In some embodiments, hybrid magnetic film 300 may further include a support layer 11.

It should be noted that the reference designator 20 is used throughout the specification to refer to various embodiments of spaced-apart magnetic segments. These segments may be referred to as tiles, portions, “islands”, sections, etc., and may be of virtually any shape or configuration. These segments may be shown herein as square or rectangular tiles, for example, but this form is not intended to be limiting. Throughout the specification, reference designator 20 shall be used to describe two or more segments of magnetic material (e.g., such a ferrite material) separated by a gap or channel from each other (i.e., spaced-apart).

Returning to FIG. 3, through-channels 30 may be at least partially filled with a magnetically permeable material 90. For example, the magnetically permeable material 90 may be magnetic particles including one or more of the materials: iron, nickel, chrome, and ferrite. In some embodiments, magnetically permeable material 90 may include thermally conductive particles.

FIG. 4 is a side, cutaway view of an embodiment of a system for a wireless power transmission (WPT), according to the present description. A WPT system 700 includes a power receiving assembly 600 (e.g., the power receiving coil and hardware on an electric vehicle) and a power transmitting assembly 500 (e.g., a power transmitting coil and hardware embedded in a road surface or at a charging station). In some embodiments, the power receiving assembly 600 includes a first magnetic film assembly 610 disposed between a first metal plate 620 and a power receiving antenna 630 (e.g., a coil of concentrically wound conductor, where the squares shown in FIG. 4 represent a cutaway view of the wound conductor). The first magnetic film assembly 610 may be any appropriate magnetic film assembly of the present description, including, but not limited to, any of hybrid magnetic film assembly 100 (FIG. 1), hybrid magnetic film assembly 200 (FIG. 2), or hybrid magnetic film 300 (FIG. 3). In some embodiments, the power transmitting assembly 500 includes a second magnetic film assembly 710 disposed between a second metal plate 720 and a power transmitting antenna 730 (e.g., a coil of concentrically wound conductor). The second magnetic film assembly 710 may be any appropriate magnetic film assembly of the present description, including, but not limited to, any of hybrid magnetic film assembly 100 (FIG. 1), hybrid magnetic film assembly 200 (FIG. 2), or hybrid magnetic film 300 (FIG. 3). Metal plates 620 and 720 may represent any substantially metallic surface, such as the metallic frame of an electric vehicle or a metallic enclosure. In some embodiments, metal plates 620 and 720 may not be present. In some embodiments, a typical optimal distance between power transmitting assembly 500 and power receiving assembly 600, when operating, may be in a range between about 100 millimeters (mm) to about 250 mm.

Various embodiments of the magnetic film assembly may exist within the scope of the present description. FIG. 5 provides a perspective view of a magnetic film 12 featuring magnetic tiles 20 disposed on a tray 22. Tray 22 includes a plurality of compartments 24, each compartment 24 having at least one sidewall 26, and each magnetic tile 20 is disposed in a different compartment 24. Magnetic film 12 may, for example, be used as first magnetic film 10 (FIG. 1 and FIG. 2), or in place of (or in addition to) magnetic tiles 20 and magnetically permeable material 90 (FIG. 3). In some embodiments, the material of tray 22 may include a magnetically permeable material or a magnetically insulative material.

FIG. 6 is a side, cutaway view of a stacked magnetic film assembly according to the present description. Stacked magnetic film assembly 100(a) may include two or more first magnetic films 10 (e.g., films 10(a) and 10(b), as shown in FIG. 6) disposed in a stacked configuration. In some embodiments, first magnetic films 10 may each include a plurality of magnetic tiles 20 (e.g., tiles 20(a) and 20(b)). In some embodiments, a second magnetic fdm 50 (e.g., fdms 50(a) and 50(b)) may be disposed on each of first magnetic films 10. In some embodiments, each of the first magnetic films 10 may include gaps 30 between adjacent tiles 20.

In some embodiments, the gaps 30 of first magnetic film 10(a) may be aligned with gaps 30 of first magnetic film 10(b). In some embodiments, the gaps 30 of first magnetic film 10(a) may be misaligned with gaps 30 of first magnetic film 10(b), such that magnetic tiles 20(a) at least partially cover gaps 30 between magnetic tiles 20(b).

In some embodiments, the stacked magnetic film assembly 100(a) may include one or more support layers 11. In other embodiments, the stacked magnetic film assembly 100(a) may include two or more of any of the previously described magnetic film assemblies disposed in a stack, including, but not limited to, any of hybrid magnetic film assembly 100 (FIG. 1), hybrid magnetic film assembly 200 (FIG. 2), or hybrid magnetic film 300 (FIG. 3).

FIG. 7 is a top view of a hybrid multilayer magnetic film, in which two or more layers of magnetic sections or tiles are disposed on each other, but intentionally misaligned. Hybrid multilayer magnetic film 400 may include two or more magnetic films 10 (e.g., tiled films 10(c) and 10(d)). Each of films 10(c) and 10(d) include a plurality of magnetic tiles 20 (e.g., tiles 20(c) and 20(d)). In some embodiments, tiles 20(c) and 20(d) may be substantially similar in size and shape. In some embodiments, tiles 20(c) and 20(d) may be dissimilar in size and/or shape. In some embodiments, films 10(c) and 10(d) are disposed such that tiles 20(c) and 20(d) are intentionally misaligned, as shown in FIG. 7, so that tiles 20(c) substantially cover gaps 30 between the tiles 20(d). Hybrid multilayer magnetic film 400 may, for example, be used as first magnetic film 10 (FIG. 1 and FIG. 2), or in place of (or in addition to) magnetic tiles 20 and magnetically permeable material 90 (FIG. 3).

Finally, FIG. 8 is a side, cutaway view of a magnetic film assembly in which the magnetic film includes two or more layers of magnetic tiles in a stacked configuration. Magnetic film assembly 800 includes a magnetic film layer 15 which includes at least two layers of magnetic tiles 20. Magnetic tiles 20 are stacked in two or more layers, and a second magnetic film 50 is disposed on the top layer of the stacked film assembly. In some embodiments, the magnetic film layer 15 may further include a dielectric film 65 between each of the layers of magnetic tiles 20. In some embodiments, there is no dielectric film 65 and the magnetic tiles 20 are stacked directly on each other. In some embodiments, the magnetic tiles 20 of one layer are substantially aligned with magnetic tiles 20 of an adjacent layer. In some embodiments, the stacks of magnetic tiles 20 may be disposed on a support layer 11 (e.g., a polymeric substrate).

Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1.1, and that the value could be 1.

Terms such as “substantially” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “substantially equal” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially equal” will mean about equal where about is as described above. If the use of “substantially parallel” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially parallel” will mean within 30 degrees of parallel. Directions or surfaces described as substantially parallel to one another may, in some embodiments, be within 20 degrees, or within 10 degrees of parallel, or may be parallel or nominally parallel. If the use of “substantially aligned” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially aligned” will mean aligned to within 20% of a width of the objects being aligned. Objects described as substantially aligned may, in some embodiments, be aligned to within 10% or to within 5% of a width of the objects being aligned.

All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control.

Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.