CROSS-REFERENCE TO RELATED APPLICATOINS

[0001] This application claims the benefit of and priority to U.S Provisional Patent Application Serial Number 62/941,953 filed November 29, 2019.

[0002] This application claims the benefit of and priority to Chinese Invention Patent Application Number 202011310435.8 filed November 20, 2020, which, in turn, claims the benefit and priority of U.S Provisional Patent Application Serial Number 62/941,953 filed November 29, 2019.

[0003] This application claims the benefit of and priority to Chinese Utility Model Patent Application Number 202022714148.5 filed November 20, 2020, which, in turn, claims the benefit and priority of U.S Provisional Patent Application Serial Number 62/941,953 filed November 29, 2019.

[0004] The entire disclosure of the above applications are incorporated herein by reference.

FIELD

[0005] The present disclosure generally relates to heat spreaders for wireless charging and/or inductive power transfer. The heat spreaders may be configured (e.g., pattered, laser cut, die cast, etc.) to avoid or suppress eddy currents from being induced in the heat spreaders due to incident magnetic fields generated by coil(s).

BACKGROUND

[0006] This section provides background information related to the present disclosure which is not necessarily prior art.

[0007] Wireless chargers may be used to charge smartphones and other electronic devices. But conventional 10 Watt, 15 Watt, 30 Watt, and above 30 Watt wireless chargers may have thermal throttle issues. For example, a smartphone may overheat during wireless charging. In which case, the wireless charging must stop or switch to a lower charging power level to allow the overheated smartphone to cool down before the wireless charging resumes. SUMMARY

[0008] This section provides a general sununary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0009] Exemplary embodiments are disclosed of heat spreaders for wireless charging, thermal management solutions for wireless charging, and devices that include heat spreaders for spreading heat generated from coil(s) or integrated circuits (ICs). The heat spreaders (e.g., natural graphite, synthetic graphite, aluminum, copper, boron nitride, etc.) may be configured (e.g., patterned, laser cut, die cast, etc.) to avoid or suppress eddy currents from being induced in the heat spreaders due to magnetic fields that are generated by coils that are incident on the heat spreaders. For example, multiple strips or portions of a heat spreading material may be positioned relative to one or more coils, such that the gaps or spaced distances between adjacent pairs of the multiple strips of the heat spreading material are oriented orthogonal to an eddy current, which would otherwise be present in the heat spreading material if the gaps were not present.

[0010] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0011] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0012] FIG. 1 illustrates an eddy current that has been induced in a graphite sheet from an incident magnetic field generated by a wireless power charging (WPC) coil.

[0013] FIG. 2 illustrates a patterned graphite heat spreader according to an exemplary embodiment of the present disclosure.

[0014] FIG. 3 illustrates a patterned graphite heat spreader according to an exemplary embodiment of the present disclosure in which the pattered graphite heat spreader includes an opening or void without graphite at about a center of the patterned graphite heater spreader. [0015] FIG. 4 shows a patterned graphite heat spreader according to an exemplary embodiment of the present disclosure.

[0016] FIG. 5 shows a patterned heat spreader according to an exemplary embodiment of the present disclosure in which the sheet of heat spreading material has been patterned via a laser cutting process.

[0017] FIG. 6 shows a patterned heat spreader according to an exemplary embodiment of the present disclosure.

[0018] FIG. 7 illustrates a patterned heat spreader according to an exemplary embodiment of the present disclosure.

[0019] FIG. 8 illustrates a patterned heat spreader according to an exemplary embodiment of the present disclosure.

[0020] FIG. 9 shows a patterned heat spreader according to an exemplary embodiment of the present disclosure.

[0021] FIG. 10 shows portions removed (e.g., laser cut, etc.) from a sheet of heat spreading material (e.g., a graphite sheet, etc.) to thereby form a pattered heat spreader according to an exemplary embodiment of the present disclosure.

[0022] FIG. 11 illustrates an exemplary device according to an exemplary embodiment of the present disclosure in which a patterned heat spreader is positioned relative to (e.g., alongside, above, on top of, etc.) WPC coils for spreading heat from the WPC coils.

[0023] FIG. 12 illustrates an exemplary wireless charger interior assembly (broadly, a device) alongside a heat spreader according to an exemplary embodiment. The heat spreader includes a first patterned heat spreader portion, a second heat spreader portion, and a third flexible heat spreader portion that extends between and thermally couples/connecting the first patterned heat spreader portion with the second heat spreader portion.

[0024] FIG. 13A is an exploded perspective view of the wireless charger interior assembly shown in FIG. 12, and illustrating a support member, coils, a ferrite sheet, a printed circuit board (PCB), and a heat sink.

[0025] FIG. 13B is perspective view of the wireless charger interior assembly shown in FIG. 13 A after the illustrated components have been assembled together. [0026] FIGS. 14 and 15 illustrate an exemplary embodiment of a graphite heat spreader installed relative to the coils shown in FIG. 13 for spreading heat from the coils.

[0027] FIGS. 16 and 17 illustrate an exemplary embodiment of a copper heat spreader installed relative to the coils shown in FIG. 13 for spreading heat from the coils.

[0028] FIGS. 18 through 20 illustrate exemplary embodiments of heat spreaders installed relative to the charger coils shown in FIG. 21 for spreading heat from the charger.

[0029] FIGS. 22 and 23 include wireless charging test results for six test specimens or samples including samples #2 and #5 having graphite heat spreaders according to exemplary embodiments.

[0030] FIG. 24 illustrates the patterned heat spreader shown in FIG. 8 and additional patterned heat spreaders according to exemplary embodiments of the present disclosure.

[0031] FIG. 25 illustrates an exemplary transmit (Tx) device (e.g., wireless charger, etc.) and an exemplary receive (Rx) device (e.g., smartphone, etc.) that include patterned heat spreaders according to exemplary embodiments of the present disclosure.

[0032] FIG. 26 illustrates the exemplary transmit (Tx) device (e.g., wireless charger, etc.) shown in FIG. 25 and an exemplary patterned heat spreader that may be used in the transmit (Tx) device according to an exemplary embodiment of the present disclosure.

[0033] FIG. 27 illustrates the exemplary receive (Rx) device (e.g. , smartphone, etc.) shown in FIG. 25 and patterned heat spreaders that may be used in the transmit (Tx) device according to exemplary embodiments of the present disclosure.

[0034] FIG. 28 illustrates a standalone heat spreader including a patterned heat spreader according to an exemplary embodiment of the present disclosure.

[0035] Corresponding reference numbers may indicate corresponding (but not necessarily identical) parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. [0037] Conventional 10 Watt, 15 Watt, 30 Watt, and above 30 Watt wireless chargers may have thermal throttle issues when charging smartphones and other electronic devices. To help alleviate thermal throttle issues and hot spots on device surfaces, some wireless chargers include built-in fans to actively cool the smartphones or other devices that are being wirelessly charged. But built-in fans tend to be noisy and require electrical power for operation.

[0038] Heat spreading materials have also been used underneath or along the backsides of wireless power charging (WPC) coils. But due to the electrical conductivity of the heat spreading materials, the magnetic field generated by the WPC coils creates an eddy current in the heat spreading materials, which will dramatically decrease the quality factor (Q-factor) of the WPC coils. The heat spreading materials may thus interfere with wireless charging due to eddy currents generated by the WPC coils in the heat spreading materials.

[0039] For example, FIG. 1 illustrates an eddy current that has been induced in a graphite sheet from a magnetic field generated by a WPC coil. The magnetic field incident on the graphite sheet causes an induced loop eddy current in the graphite sheet. The eddy current in the graphite sheet generates an opposite field to the WPC coil and reduces inductance of the WPC coil. The eddy current also causes energy loss thereby reducing the quality factor (Q-factor) of the WPC coil. [0040] After recognizing the above, exemplary embodiments were developed and/or are disclosed herein of heat spreaders for wireless charging systems and/or inductive power transfer systems. The heat spreaders are configured (e.g., patterned, laser cut, die cast, etc.) to avoid or suppress eddy currents from being induced in the heat spreaders due to magnetic fields that are generated by coils and that are incident on the heat spreaders. As disclosed herein, the heat spreaders may be used in three different application places in a wireless charging systems, e.g., a wireless charger (broadly, a transmit (Tx) device), a smartphone (broadly, a receive (Rx) device), an/or standalone heat spreader (e.g., an device case or cooling pad, etc.). The heat spreaders may be used for spreading heat in-plane or within one plane and/or for transferring heat from plane A to plane B.

[0041] In exemplary embodiments, multiple strips or portions of a heat spreading material (e.g., natural graphite, synthetic graphite, aluminum, copper, boron nitride, etc.) may be positioned relative to one or more coils, such that the gaps or spaced distances between adjacent pairs of the multiple strips of the heat spreading material are oriented orthogonal to an eddy current, which would otherwise be present in the heat spreading material if the gaps were not present.

[0042] In exemplary embodiments disclosed herein, a heat spreading material (e.g., natural graphite, synthetic graphite, aluminum, copper, boron nitride, etc.) is configured (e.g., patterned, laser cut, etched, annularly shaped, cut, die cast, etc.) to have electrically non-conductive or dielectric areas (e.g., slots, slits, air gaps, etc.) between adjacent spaced-apart portions (e.g., strips, etc.) of the heat spreading material. The dielectric areas are generally perpendicular or orthogonal to the direction of the electrical current of the coil(s). The dielectric areas are configured to avoid attenuation of the magnetic field and prevent an eddy current from being induced in the heat spreader due to the incident magnetic field generated by the coil(s). Advantageously, the use of patterned heat spreaders (e.g., patterned natural and/or synthetic graphite sheets, etc.) as disclosed herein allows for the spreading of heat without negatively affecting the magnetic and electrical performance of the coils.

[0043] In exemplary embodiments, an electrically and thermally conductive sheet material is configured to avoid attenuation of an externally applied AC magnetic field and suppress eddy currents. In exemplary embodiments, a heat spreader (e.g., a synthetic or natural graphite sheet, aluminum sheet, etc.) includes cuts, slits, or slots that are orthogonal to the direction of the current of the coil or induced loop current on the heat spreader. The cuts, slits or slots between the electrically-conductive strips or pieces of the heat spreader stop the induced loop current. The pattern of cuts, slits, or slots on the heat spreader (e.g., graphite sheet, aluminum sheet, etc.) allow heat spreading across the surface or in-plane without affecting the electrical performance of the wireless charging coil and NFC coil.

[0044] In exemplary embodiments, a patterned heat spreader may be positioned above and along a topside of the coil(s) to transfer and spread heat from the top of the coil(s). Transferring and spreading heat from the top of the coil(s) tends to be more efficient and effective than transferring and spreading heat via a heat spreader positioned underneath and along the backside of the coil(s). [0045] Also disclosed herein are exemplary embodiments of thermal management solutions for wireless charging and/or inductive power transfer that include patterned heat spreaders. Exemplary methods are further disclosed that include using patterned heat spreaders for spreading heat generated from the coil(s) during wireless charging and/or inductive power transfer.

[0046] Additionally, exemplary embodiments are disclosed of devices (e.g., 10 Watt wireless charger, 15 Watt wireless charger, 30 Watt wireless charger, above 50 Watt wireless charger, smartphone, portable device, etc.) that include patterned heat spreaders, which help to alleviate thermal throttle issues. In an exemplary embodiment, a device includes a patterned graphite sheet configured to eliminate the thermal throttle issue, to limit device surface temperature to a maximum of 60 degrees Celsius thereby avoiding hot spots and improving the human touch experience, and/or to provide a more uniform or homogeneous distribution of surface temperature.

[0047] FIG. 2 illustrates a patterned graphite heat spreader 200 according to an exemplary embodiment of the present disclosure. As shown in FIG. 2, the patterned graphite heat spreader 200 includes a pattern defined by a plurality of strips 204 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 208. The gaps or slots 208 extend between the strips 204 and through or beyond the side edges of the patterned heat spreader 200, such that the gaps or slots 208 are open ended along the side edges of the patterned heat spreader 200.

[0048] The patterned graphite heat spreader 200 includes first and second diagonally extending gaps, slots, or slits 212, 216. The gaps 212, 216 are defined generally between spaced apart end portions of the strips 204. As shown in FIG. 2, the first diagonal gap 212 extends from the left upper comer to the right lower comer, whereas the second diagonal gap 216 extends from the lower left comer to the upper right comer. The first and second diagonal gaps or slots 212, 216 extend entirely across or through the comers of patterned heat spreader 200. Accordingly, each of the first and second diagonal gaps or slots 212, 216 is an open ended gap or slot having both ends open in this exemplary embodiment.

[0049] The gaps or slots 208 also extend from the side edges of the patterned heat spreader 200 to the first or second diagonal gaps 212, 216, such that the gaps or slots 208 are also open ended along the diagonal gaps 212, 216. Accordingly, each gap or slot 208 is an open ended gap or slot having both ends open.

[0050] The first and second diagonal gaps 212, 216 intersect at about a middle of the patterned graphite heat spreader 200 and define an overall X-shaped gap. Stated differently, the first and second diagonal gaps 212, 216 cooperatively define four generally triangular portions of the heat spreader 200. In an exemplary embodiment, the patterned heat spreader 200 may be integrally formed (e.g., via laser cutting, etc.) from a same single sheet of natural and/or synthetic graphite or other heat spreading material (e.g., an aluminum sheet, copper sheet, boron nitride sheet, etc.). In another exemplary embodiment, a patterned heat spreader may be assembled from discrete pieces (e.g., four separate triangular pieces, etc.) of heat spreading material(s) that are placed together to thereby collectively define the patterned heat spreader. In this latter example, the different discrete pieces of the heat spreading material(s) may be all made from the same heat spreading material, or one or more pieces may be made from a different heat material than at least one other piece.

[0051] The strips 204 may be integrally formed from a same single sheet of synthetic or natural graphite. The gaps 208, 212, 216 may be defined by areas from which portions of the graphite sheet (broadly, heat spreading material) have been removed (e.g., via laser cutting, etching, an automated material removal process, etc.). For example, the gaps 208, 212, 216 may comprise relatively narrow slots or air gaps that are laser cut into the graphite sheet. The gaps 208, 212, 216 are devoid of the electrically-conductive graphite and instead include air or other dielectric material. The air or other dielectric material within the gaps 208, 212, and 216 helps to prevent the eddy current 220 from being induced in the patterned graphite heat spreader 200.

[0052] In exemplary embodiments, the gaps 208, 212, and/or 216 may include or be provided with (e.g., filled with, have dispensed therein, etc.) an electrical nonconductor or dielectric material in addition to or as an alternative to air. For example, the gaps 208, 212, and/or 216 may include or be provided with plastic or other dielectric material (e.g., dielectric material dispensed via a nozzle into the gaps, etc.) for improved mechanical strength and/or to form part of an enclosure or housing. Or, for example, the gaps 208, 212, and/or 216 may include or be provided with a thermally-conductive dielectric thermal interface material for improved thermal performance and heat transfer, e.g., enhanced in-plane heat spreading in the X-Y direction laterally away from a WPC coil(s), etc. As yet another example, the gaps 208, 212, and/or 216 may be filled or include dielectric material such that strips 204 of heat spreading material and the dielectric material within the gaps 208, 212, and/or 216 have a unitary, monolithic, or one-piece construction. In this latter example, the combination of the strips 204 of heat spreading material and the dielectric material within the gaps 208, 212, and/or 216 may be configured for use as a multifunctional product, such as a cover or enclosure having heat spreading functionality that may be used instead of or as a replacement to a conventional plastic cover on a wireless transmitter side.

[0053] With continued reference to FIG. 2, the heat spreader 200 is patterned or configured such that the gaps 208 are generally perpendicular or orthogonal to the direction of the electrical current of the WPC coil. The gaps or spaced distances 208 between adjacent pairs of the strips 204 are oriented orthogonal to an eddy current 220 (shown for purposes of clarity), which would otherwise be present in the heat spreading material if the gaps 208, 212, 216 were not present.

[0054] In this exemplary embodiment, the gaps 208, 212, 216 are defined by areas from which portions of the heat spreading material have been removed. But in other exemplary embodiments, the gaps 208, 212, 216 may be defined by the placement (e.g., manual and/or automatic placement, etc.) of multiple strips 204 in a spaced apart pattern relative to each other. For example, the strips 204 may be individually placed onto and attached (e.g., adhesively attached or glued, etc.) to a support surface (e.g., a surface of WPC coil(s), a substrate, a supporting or carrier film, etc.) such that the strips 204 are in patter in which the gaps or spaced distances 208 between adjacent pairs of the strips 204 are oriented orthogonal to an eddy current, which would otherwise be present in the heat spreading material if the gaps 208 were not present.

[0055] The graphite strips 204 may be quadrilaterals and/or triangles. The pattered graphite heat spreader 200 may have an overall generally rectangular shape. Alteratively, the strips 204 and the pattered graphite heat spreader 200 may be shaped differently. For example, the strips 204 and/or gaps 208 may be rectangles, parallelograms, polygons, or the like with parallel edges, pie wedges, triangles, or the like with non-parallel edges. Accordingly, the present disclosure should not be limited to heat spreaders or strips of heat spreading materials having any one particular shape. The strips may include a wide range of shapes that are structured or configured with gaps, slots or dielectric portions to pass the magnetic field generated by WPC coil(s) and/or to inhibit eddy currents from being induced in the heat spreading material from an incident magnetic field generated by the WPC coil(s).

[0056] Exemplary heat spreading materials that may be used for the patterned heat spreader 200 shown in FIG. 2 include natural graphite, synthetic graphite, aluminum, copper, boron nitride, sheets thereof, combinations thereof, etc. By way of example, a patterned heat spreader may be made from a flexible sheet of natural and/or synthetic graphite. A patterned heat spreader may be made from a graphite sheet from Laird Technologies, such as a Tgon™ 800 series natural graphite sheet (e.g., Tgon™ 805, 810, 820, etc.), Tgon™ 8000 series graphite sheet, Tgon™ 9000 series synthetic graphite sheet (e.g., Tgon™9017, 9025, 9040, 9070, 9100, etc.), other graphite sheet materials, etc. Table 1 below includes additional details about Tgon™ 9000 series synthetic graphite from Laird Technologies. Accordingly, the present disclosure should not be limited to use with any one particular heat spreading material.

[0057] By way of example only, the patterned graphite heat spreader 200 may have the following dimensions. The strips 204 may have a width of about 1.8 millimeters (mm). The gaps or slots 208 may have a width of about 0.2 mm. The first and second diagonal gaps 212, 216 may have a width of about 0.2 mm. The patterned graphite heat spreader 200 may have an overall width of about 100 mm, an overall length of about 100 mm, and a sheet thickness within a range from about 25 micrometers (um) to about 40 um (e.g., 25 um, 30 um, 35 um, 40 um, etc.). Accordingly, this example patterned graphite heat spreader 200 has a slot/gap width to strip width ratio of 1/9 (.2 mm/1.8 mm). The specific dimensions disclosed herein are examples only as alternative embodiments may be configured differently. For example, a pattered heat spreader may have a strip width wider or narrower than 1.8 mm (e.g., 3 mm, etc.), a slot/gap width wider or narrower than 0.2 mm (e.g., 1 mm, etc.), a ratio of slot/gap width to strip width greater or less than 1/9 (e.g., 1/3, etc.), a sheet thickness less than 25 um or greater than 40 um, an overall length greater than or less than 100 mm, and/or a width greater than or less than 100 mm, etc. [0058] In other exemplary embodiments, a heat spreader may be configured to have gaps/slots of varying widths, strips of varying widths, and/or ratios of slot/gap width to strip width that varies at different locations along the heat spreader. For example, the first and second diagonal gaps 212, 216 may comprise slots that are laser cut or otherwise farmed in the graphite or other heat spreading material to have a width greater than the width at which the gaps or slots 208 are laser cut or otherwise formed in the graphite or other heat spreading material. In this example, the larger width of the gaps 212, 216 may allow for easier peeling off or removal of the laser cut pieces of the heat spreading material from a supporting film or substrate after the laser cutting process is completed.

[0059] FIG. 3 illustrates a pattered graphite heat spreader 300 according to an exemplary embodiment of the present disclosure. Similar to the pattered graphite heat spreader 200 shown in FIG. 2, the pattern graphite heat spreader 300 also includes a pattern defined by a plurality of strips 304 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 308. The gaps or slots 308 extend between the strips 304 and through or beyond the side edges of the patterned heat spreader 300, such that the gaps or slots 308 are open ended along the side edges of the patterned heat spreader 300.

[0060] The pattered graphite heat spreader 300 also includes diagonally extending gaps, slots, or slits 312, 316 defined generally between spaced apart end portions of the strips 304. The gaps 312, 316 are defined generally between spaced apart end portions of the strips 204.

[0061] In this exemplary embodiment, the patterned graphite heat spreader sheet 300 includes an opening 324 located at about a center of the patterned graphite heater spreader 300. Accordingly, the opening 324 may be configured to be aligned with a WPC coil (e.g., vertically aligned with the opening of the WPC coil, etc.) when the pattern graphite heat spreader 300 is positioned (e.g., alongside, above, and/or on top of the WPC coil, etc.) for spreading heat from the WPC coil(s).

[0062] Because the heat is preferably laterally moved or spread away from the WPC coil(s), the opening 324 preferably does not significantly diminish the heat spreading capability of the patterned heat spreader 300. Advantageously, the opening 324 preferably will allow at least a portion (e.g., a large portion, significant portion, a majority, etc.) of the magnetic field generated by the WPC coil(s) to freely pass through the opening 324 (e.g., freely pass through the air or other dielectric material within the opening 324, etc.) without inducing an eddy current within the opening 324. In addition, the absence of the heat spreading material within the opening 324 may also reduce the overall weight and material costs of the patterned heat spreader 300.

[0063] In exemplary embodiments, the opening 324 may comprise a cutout in the graphite or other heat spreading material that is formed by laser cutting or other cutting or material removal processes. In other exemplary embodiments, the opening 324 may instead be defined by the individual placement of the strips 304 onto a support surface without individually placing any strips 304 where the opening 324 is to be located.

[0064] In the exemplary embodiment shown in FIG. 3, the opening 324 may comprise a cutout that is cut (e.g., laser cut, etc.) or otherwise formed (e.g., via die casting, etc.) in a sheet of heat spreading material (e.g., natural graphite, synthetic graphite, aluminum, copper, boron nitride, etc.) The opening 324 and/or the gaps 304, 312, 316 may be devoid of any electrically-conductive heat spreading material in this exemplary embodiment.

[0065] In other exemplary embodiments, the opening 324 and/or the gaps 304, 312, and/or 316 may include or be provided with (e.g. , filled with, have dispensed therein, etc.) an electrical non-conductor or dielectric material in addition to or as an alterative to air. For example, the opening 324 and/or the gaps 304, 312, and/or 316 may include or be provided with plastic or other dielectric material (e.g., dielectric material dispensed via a nozzle into the gaps, etc.) for improved mechanical strength and/or to form part of an enclosure or housing. Or, for example, the opening 324 and/or the gaps 304, 312, and/or 316 may include or be provided with a thermally-conductive dielectric thermal interface material for improved thermal performance and heat transfer, e.g., enhanced in-plane heat spreading in the X-Y direction laterally away from a WPC coil(s), etc. As yet another example, the opening 324 and/or the gaps 308, 312, and/or 316 may be filled or include dielectric material such that strips 304 of heat spreading material and the dielectric material within the opening 324 and/or the gaps 308, 312, and/or 316 have a unitary, monolithic, or one-piece construction. In this latter example, the combination of the strips 304 of heat spreading material and the dielectric material within the opening 324 and/or the gaps 308, 312, and/or 316 may be configured for use as a multifunctional product, such as a cover or enclosure having heat spreading functionality that may be used instead of or as a replacement to a conventional plastic cover on a wireless transmitter side.

[0066] FIG. 4 shows a patterned graphite heat spreader 400 according to an exemplary embodiment of the present disclosure. Similar to the patterned graphite heats 200 (FIG. 2) and 300 (FIG. 3), the patterned graphite heat spreader 400 also includes a patter defined by a plurality of strips 404 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 408. The patterned graphite heat spreader 400 also includes first and second diagonally extending gaps, slots, or slits 412, 416 defined generally between spaced apart end portions of the strips 404. The first diagonal gap 412 extends from the left upper comer to the right lower comer, whereas the second diagonal gap 416 extends from the lower left comer to the upper right comer.

[0067] The patterned graphite heat spreader sheet 400 includes an opening 424 located at about a center of the patterned graphite heater spreader 400. The opening 424 may be configured to be aligned with a WPC coil (e.g., vertically aligned with the opening of the WPC coil, etc.) when the pattern graphite heat spreader 400 is positioned (e.g., alongside, above, and/or on top of the WPC coil, etc.) for spreading heat from the WPC coil(s).

[0068] FIG. 5 shows a pattered heat spreader 500 according to an exemplary embodiment of the present disclosure. FIG. 5 generally shows a sheet 526 of heat spreading material having a pattern formed via a laser cutting process. Similar to the patterned graphite heat spreader 200 (FIG. 2), the patter of the heat spreader 500 includes multiple strips (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits. The patterned heat spreader 500 also includes first and second diagonally extending gaps, slots, or slits defined generally between spaced apart end portions of the strips of heat spreading material.

[0069] FIG. 6 shows a patterned heat spreader 600 according to an exemplary embodiment of the present disclosure. The pattern heat spreader 600 includes multiple strips (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits. The strips are generally rectangular and may be generally parallel to each other when positioned along support surface for spreading heat from a WPC coil(s). [0070] FIG. 7 illustrates a patterned heat spreader 700 according to an exemplary embodiment of the present disclosure. Similar to the patterned heat spreader 200 (FIG. 2), the patter of the heat spreader 700 includes multiple strips 704 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 708. The pattered heat spreader 700 also includes first and second diagonally extending gaps, slots, or slits 712, 716 defined generally between spaced apart end portions of the strips 708 of heat spreading material. In this exemplary embodiment, the first and second diagonal gaps or slots 712, 716 have a width of about 1.98 mm and are wider than the gaps or slots 708 between adjacent pairs of the strips 704. The specific dimensions disclosed herein are examples only as alternative embodiments may be configured differently.

[0071] FIG. 8 illustrates a pattered heat spreader 800 according to an exemplary embodiment of the present disclosure. The patterned heat spreader 800 includes multiple strips 804 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 808. The patterned heat spreader 800 also includes first and second diagonally extending gaps, slots, or slits 812, 816 defined generally between spaced apart end portions of the strips 808 of heat spreading material. The first diagonal gap 812 extends from the left upper comer to the right lower comer, whereas the second diagonal gap 816 extends from the lower left comer to the upper right comer. In this exemplary embodiment, the first and second diagonal gaps or slots 812, 816 extend across the patterned heat spreader 800 but do not extend through the comers of patterned heat spreader 800. Accordingly, each of the first and second diagonal gaps or slots 812, 816 is a closed ended gap or slot having both ends that are closed and not open in this exemplary embodiment.

[0072] FIG. 9 shows a patterned heat spreader 900 according to an exemplary embodiment of the present disclosure. FIG. 10 shows portions 1001 removed (e.g., laser cut, etc.) from a sheet of heat spreading material (e.g., a graphite sheet, etc.) to thereby form a pattered heat spreader (e.g., heat spreader 900 (FIG. 9), etc.) according to an exemplary embodiment of the present disclosure.

[0073] FIG. 11 illustrates an exemplary device 1102 (e.g., a smartphone, etc.) according to an exemplary embodiment of the present disclosure in which a patterned heat spreader 1100 is positioned relative (e.g., alongside, above, on top of, etc.) the WPC coils 1132 for spreading heat from WPC coils 1132. In this example, the patterned heat spreader 1100 is positioned along a top side of the WPC coils 1132. A ferrite sheet or plate 1136 is positioned along an opposite bottom side of the WPC coils 1132 generally between a battery 1140 of the WPC coils 1132. The patterned heat spreader 1100 may comprise or be similar to the patterned heat spreader 200 (FIG. 2), 300 (FIG. 3), 400 (FIG. 4), 500 (FIG. 5), 600 (FIG. 6), 700 (FIG. 7), 800 (FIG. 8), 900 (FIG. 9), 1000 (FIG. 10), etc. The patterned heat spreader 1100 may comprise natural graphite, synthetic graphite, aluminum, copper, and boron nitride.

[0074] Electrical test results for different test setups including WPC All transmitter (Tx) coil modules 1232 with test conditions of 100 kilohertz (KHz)/0.5 Volts (V) will now be provided. But these electrical test results are examples only as other exemplary embodiments may be configured differently (e.g., made from different materials, have different patterns, shapes, and/or sizes, etc.) and/or tested for other coil modules, such that different electrical test results would be achieved.

[0075] A first test setup included a non-pattemed ferrite sheet or plate along a bottom of a coil. In one test, the electrical test results for the first test setup included an inductance of 6.55 microhenries (uH), a coil Q-factor (Q) of 88, and resistivity (Rs) of 46.56 milliohms (mΩ). In another test, the electrical test results for the first test setup similarly included an inductance of 6.57 microhenries (uH), a coil Q-factor (Q) of 91, and resistivity (Rs) of 45 milliohms (mΩ).

[0076] A second test setup included a non-patterned ferrite sheet or plate along the bottom of the coil, and a non-pattemed graphite along the bottom of the ferrite sheet/plate. Neither the ferrite sheet/plate nor the graphite sheet was patterned for the second setup. The graphite sheet comprised a standard Tgon™ 9025 graphite sheet. The electrical test results for the second test setup included an inductance of 6.55 microhenries (uH), a coil Q-factor (Q) of 77, and resistivity (Rs) of 53.6 milliohms (mΩ).

[0077] A third test setup included a non-pattemed ferrite sheet/plate along the bottom of the coil, and a graphite sheet along the bottom of the ferrite sheet/plate. In this third test setup, the ferrite sheet/plate was not patterned, but the graphite sheet was pattered. More specifically, the graphite sheet comprised a Tgon™ 9025 graphite sheet patterned according to the exemplary embodiment of the heat spreader 400 shown in FIG. 4. The electrical test results for the third test setup included an inductance of 6.57 microhenries (uH), a coil Q-factor (Q) of 91, and resistivity (Rs) of 45 milliohms (mΩ).

[0078] A fourth test setup included a non-pattemed ferrite sheet/plate along the bottom of the coil, and a non-pattemed graphite sheet along the top of the coil. Neither the ferrite sheet/plate nor the graphite sheet was patterned for the fourth setup. The graphite sheet comprised a standard Tgon™ 9025 graphite sheet. The electrical test results for the second test setup included an inductance of 6.47 microhenries (uH), a coil Q-factor (Q) of 8.48, and resistivity (Rs) of 472.8 milliohms (mΩ). Notably, this fourth test setup produced a coil Q-factor (Q) that was considerably worse than all of the other test setups shown in FIG. 12 and generated more heat.

[0079] A fifth test setup included a non-pattemed ferrite sheel/plate along the bottom of the coil, and a graphite sheet along the top of the coil. In this fifth test setup, the ferrite sheet/plate was not patterned, but the graphite sheet was patterned. More specifically, the graphite sheet comprised a Tgon™ 9025 graphite sheet patterned according to the exemplary embodiment of the heat spreader 400 shown in FIG. 4. The electrical test results for the fifth test setup included an inductance of 6.57 microhenries (uH), a coil Q-factor (Q) of 82, and resistivity (Rs) of 49.9 milliohms (mΩ).

[0080] In the second, third, fourth, and fifth test setups of FIG. 12, the Tgon TM 9025 graphite sheets are Tgon™ 9000 series graphite sheets having thickness of about 25 micrometers. Tgon™ 9000 series graphite sheets comprise synthetic graphite thermal interface materials having carbon in-plane mono-crystal structures and that are ultra-thin, light-weight, flexible and offer excellent in-plane thermal conductivity. Tgon™ 9000 series graphite sheets are useful for heat spreading applications where in-plane thermal conductivity dominates and in limited spaces. Tgon™ 9000 series graphite sheets may have a thermal conductivity from about 500 to about 1900W/mK, may help reduce hot spots and protect sensitive areas, may enable slim device designs due to the ultra-thin sheet thickness of about 17 micrometers to 100 micrometers, may be light weight (e.g., a density from about 2.05 g/cm ³ to 2.25 g/cm ³ for a thickness of 17 micrometers or 25 micrometers, etc.), may be flexible and able to withstand more than 10,000 times bending with radius of 5 millimeters. Table 1 below includes Tgon™ graphite materials (and properties thereof) that may be used as a heat spreading material in exemplary embodiments. TABLE 1

[0081] Thermal management is an important consideration for the wireless charger and the device being charged by the wireless charger. For example, the charging mode may switch to a slow charge mode if the device temperature reaches 45 °C or above. Accordingly, wireless charging performance may be improved by removing or dissipating hot spot(s) from the device being charged (e.g., smartphone, etc.) so that the device temperature remains below 45 °C and the charging mode does not switch from a fast charge mode to a slow charge mode.

[0082] As disclosed herein, exemplary embodiments of patterned heat spreaders (e.g., patterned graphite or copper sheets, etc.) may be added to devices (e.g., wireless chargers, smartphones, other devices, etc.) to help remove hot spot(s), make device temperature more uniform or homogeneous, reduce thermal throttle, spread heat (within one plane) and/or transfer heat (from plane A to plane B) generated by the coils without affecting magnetic and electrical performance of the coils. The use of such patterned heat spreaders provides improvements to the fast charge time in such exemplary embodiments. But as recognized herein, the smart phone or other device being charge may have a hot spot(s) that remains such that the device temperature may increase to an overheating limit that causes the charge mode to switch to a slow charge mode. As further recognized herein, additional improvements in the fast charge time may therefore be achieved by removing or reducing the hot spot(s) on the smartphone or other device being charged by using patterned heat spreaders (e.g., patterned graphite or copper sheets, etc.) in the wireless charger, smartphone, or other device, to thereby transfer heat from a heat source (e.g., coils, etc.) to a heat sink. This, in turn, can help further increase the amount of time for the fast charge mode (e.g., from 1350 seconds to more than 3500 seconds, a 100% or more increase for the fast charge time, etc.).

[0083] In exemplary embodiments, a first patterned heat spreader (e.g., a first patterned graphite or copper sheet including cuts, slots, slits, and/or gaps, etc.) may be configured and/or used to spread heat from a hot spot source(s) while also suppressing induced eddy current in the heat spreader without degrading coil electric performance. A second heat spreader (e.g., a second graphite or solid sheet, etc.) may be configured and/or used to transfer heat from the first patterned graphite sheet to a heat sink(s).

[0084] The first and second heat spreaders may comprise a single, monolithic piece or sheet (e.g., a single graphite or copper sheet, etc.) integrally connected together. Or, the first and second heat spreaders may comprise separate sheets (e.g., two or more graphite sheets, copper sheets, etc.), which sheets are thermally coupled or connected together, e.g., via a third heat spreader, etc. The heat spreaders may comprise one or more synthetic graphite sheet(s) and/or natural graphite sheet(s). Additionally, or alteratively, exemplary embodiments of the heat spreaders may comprise one or more of a copper (e.g., copper foil or sheet, etc.), aluminum (e.g., aluminum foil, sheet, sheet metal, die casting, etc.), graphite (e.g., synthetic graphite sheet, natural graphite sheet, etc.), electrically- conductive sheet, electrically-conductive tape, electrically-conductive adhesive, a combination thereof, etc.

[0085] In exemplary embodiments, heat spreading efficiency and performance may be significantly improved by using the second heat spreader (e.g., second graphite portion, etc.) to conduct heat from the first patterned heat spreader (e.g., first patterned graphite portion, etc.) to a heat sink. The improved heat spreading efficiency may help keep the smartphone or other device being charged at a low enough temperature such that the fast charge mode may continue and not switch to a slow charge mode as the temperature remains below an overheating condition.

[0086] FIG. 12 illustrates an exemplary electronic device 1202 (e.g., wireless charger interior assembly, etc.) alongside a heat spreader 1200 (e.g., a natural and/or synthetic graphite sheet, copper, etc.) according to an exemplary embodiment. The heat spreader 1200 includes a first patterned heat spreader portion 1244, a second heat spreader portion 1248 (e.g., solid portion without any slots/slits/gaps, etc.), and a third flexible heat spreader portion 1252 (e.g., integrally formed living hinge, etc.). The third flexible heat spreader portion 1252 extends between and thermally couples/connecting the first patterned heat spreader portion 1244 with the second heat spreader portion 1248.

[0087] As shown in FIG. 12, the first patterned heat spreader portion 1244 includes a pattern defined by a plurality of strips, pieces, or areas of the heat spreading material 1204 that are spaced apart from each other by gaps, slots, slits, or areas devoid of the heat spreading material 1208. In this exemplary embodiment, the areas of heat spreading material 1204 and the areas devoid of heat spreading material 1208 may generally define a starburst patter in which the areas 1204, 1208 radiate or extend linearly outwardly from a generally center location 1246 of the first patterned heat spreader portion 1244. As another example, the areas of heat spreading material 1204 and the areas devoid of heat spreading material 1208 may generally define a spoked pattern in which the areas 1204, 1208 extend linearly outwardly from the generally center location or hub 1246 of the first patterned heat spreader portion 1244.

[0088] In this exemplary embodiment, the center location or hub 1246 of the first pattered heat spreader portion 1244 includes the heat spreading material. In other exemplary embodiments, the first patterned heat spreader portion 1244 may include an opening located at about the center 1246 of the first pattered graphite heater spreader 1244. In which case, the opening may be configured to be aligned with an opening in a coil when the first pattered heat spreader portion 1244 is positioned (e.g., alongside, above, and/or on top of a coil(s), etc.) for spreading heat from the coil(s). [0089] In this exemplary embodiment, the gaps, slots, slits, or areas devoid of heat spreading material 1208 do not extend outwardly through or beyond side edges of the first patterned heat spreader portion 1244, such that the gaps, slots, slits, or areas devoid of heat spreading material 1208 are closed ended. Alternatively, one or more of the gaps, slots, slits, or areas devoid of heat spreading material 1208 may extend through or beyond the side edges of the first patterned heat spreader portion 1244, such that the gaps, slots, slits, or areas devoid of heat spreading material 1208 are open ended along the side edges of the first patterned heat spreader portion 1244.

[0090] In an exemplary embodiment, the first patterned heat spreader portion 1244 may be integrally formed (e.g., via laser cutting, etc.) from a same single sheet of natural and/or synthetic graphite or other heat spreading material (e.g., an aluminum sheet, aluminum die casting, copper sheet, boron nitride sheet, electrically-conductive sheet, electrically-conductive tape, electrically-conductive adhesive, etc.). For example, the strips, pieces, areas of the heat spreading material 1204 may be integrally formed from a same single sheet of synthetic or natural graphite. The gaps, slots, slits, or areas devoid of heat spreading material 1208 may be defined by areas from which portions of the graphite sheet (broadly, heat spreading material) have been removed (e.g., via laser cutting, etching, an automated material removal process, etc.). For example, the gaps, slots, slits, or areas devoid of heat spreading material 1208 may comprise relatively narrow slots or air gaps that are laser cut into the graphite sheet. The gaps, slots, slits, or areas 1208 are devoid of the electrically-conductive graphite and instead include air or other dielectric material. The air or other dielectric material within the gaps, slots, slits, or areas 1208 help to prevent an eddy current from being induced in the first patterned heat spreader portion 1244.

[0091] In exemplary embodiments, the gaps, slots, slits, or areas 1208 may include or be provided with (e.g., filled with, have dispensed therein, etc.) an electrical non-conductor or dielectric material in addition to or as an alterative to air. For example, the gaps, slots, slits, or areas 1208 may include or be provided with plastic or other dielectric material (e.g., dielectric material dispensed via a nozzle into the gaps, etc.) for improved mechanical strength and/or to form part of an enclosure or housing. Or, for example, the gaps, slots, slits, or areas 1208 may include or be provided with a thermally- conductive dielectric thermal interface material for improved thermal performance and heat transfer, e.g., enhanced in-plane heat spreading in the X-Y direction laterally away from a coil(s), etc. As yet another example, the gaps, slots, slits, or areas 1208 may be filled or include dielectric material such that the slots, strips, pieces, or areas of heat spreading material 1204 and the dielectric material within the gaps, slots, slits, or areas 1208 have a unitary, monolithic, or one-piece construction. In this latter example, the combination of the strips, pieces, or areas of heat spreading material 1204 and the dielectric material within the gaps, slots, slits, or areas 1208 may be configured for use as a multifunctional product, e.g., a cover or enclosure having heat spreading functionality, etc.

[0092] With continued reference to FIG. 12, the first patterned heat spreader portion 1244 is pattered or configured such that the gaps, slits, slots, or areas 1208 will generally be perpendicular or orthogonal to the direction of the electrical current of the coil 1232. The gaps, slits, slots, areas 1208 between adjacent pairs of the strips, pieces, areas of heat spreading material 1204 are oriented orthogonal to an eddy current, which would otherwise be present in the heat spreading material if the gaps, slits, slots, areas 1208 were not present.

[0093] The gaps, slots, slits, or areas devoid of the heat spreading material 1208 may be quadrilaterals and/or triangles. The first patterned graphite heat spreader portion 1244 may have an overall generally rectangular shape with rounded comers. Alteratively, the gaps, slots, slits, or areas devoid of the heat spreading material 1208 and the first pattered graphite heat spreader portion 1244 may be shaped differently. For example, gaps, slots, slits, or areas devoid of the heat spreading material 1208 may be rectangles, parallelograms, polygons, or the like with parallel edges, pie wedges, triangles, or the like with non-parallel edges. Accordingly, the present disclosure should not be limited to heat spreaders having any one particular shape. The strips, pieces, or areas of heat spreading material 1204 may include a wide range of shapes that are structured or configured with gaps, slots, slits, or areas devoid of the heat spreading material 1208 to pass the magnetic field generated by the coil(s) 1232 and/or to inhibit eddy currents from being induced in the heat spreading material from an incident magnetic field generated by the coil(s) 1232.

[0094] With continued reference to FIG. 12, the second heat spreader portion 1248 is shown as a solid portion without any gaps, slots, slits, or areas devoid of the heat spreading material (e.g., graphite, copper, aluminum, electrically-conductive sheet, electrically-conductive tape, electrically-conductive adhesive, etc.). Alteratively the second heat spreader portion 1248 may include one or more gaps, slots, slits, or areas devoid of the heat spreading material in other exemplary embodiments.

[0095] The third heat spreader portion 1252 extends between and thermally couples/connecting the first pattered heat spreader portion 1244 with the second heat spreader portion 1248. In this exemplary embodiment, the third heat spreader portion 1252 comprises a flexible member (e.g., living hinge, etc.) that is integrally formed along with the first and second heat spreader portions 1244, 1248 from a single sheet of heat spreading material (e.g., a graphite sheet, copper sheet, etc.). The third heat spreader portion 1252 is sufficiently flexible to be flexed or wrapped around and extend across an edge portion within the assembly (e.g., an edge portion defined by ferrite and aluminum plate within the wireless charger, etc.). With this flexibility, the third heat spreader portion 1252 is able to thermally couple/connect the first and second heat spreader portions 1244, 1248 even when they are disposed along opposite first and second sides (e.g., upper and lower sides, etc.) of the coils 1232. See, for example, the heat spreader 1400 shown in FIGS. 14 and 15 and the heat spreader 1600 shown in FIGS. 16 and 17.

[0096] Exemplary heat spreading materials that may be used for the heat spreader 1200 shown in FIG. 12 include natural graphite, synthetic graphite, aluminum, copper, boron nitride, sheets thereof, electrically-conductive sheets, electrically- conductive tape, electrically-conductive adhesive, combinations thereof, etc. By way of example, the heat spreader 1200 may be made from a flexible sheet of natural and/or synthetic graphite. The heat spreader 1200 may be made from a graphite sheet from Laird Technologies, such as a Tgon™ 800 series natural graphite sheet (e.g., Tgon™ 805, 810, 820, etc.), Tgon™ 8000 series graphite sheet, Tgon™ 9000 series synthetic graphite sheet (e.g., Tgon™9017, 9025, 9040, 9070, 9100, etc.), other graphite sheet materials, etc. Table

1 includes additional details about Tgon TM 9000 series synthetic graphite from Laird Technologies. Accordingly, the present disclosure should not be limited to use with any one particular heat spreading material.

[0097] As shown in FIGS. 13A and 13B, the electronic device 1202 may comprise a wireless charger. But the heat spreader 1200 may also or instead be used with other devices to be wirelessly charged and/or wirelessly powered via inductive power transfer. FIG. 13A illustrates exemplary components of a wireless charger interior assembly 1202, including a foam member 1250 (e.g., microcellular urethane foam, other foam, other resilient material, etc.), support member 1252 (e.g., plastic-BKT, a mid-plate, middle deck, mid-frame housing, etc.), coils 1232, ferrite 1236, an aluminum plate 1256, a printed circuit board (PCB) 1258, a 12-pin header 1259, an EMI cover/shield or heat sink

1260, and an insulation film 1261. [0098] FIGS. 14 and 15 illustrate an exemplary embodiment of a graphite heat spreader 1400 installed relative to the wireless charger coils 1232 shown in FIG. 13 for spreading heat from the wireless charger coils 1232. Similar to the heat spreader 1200 shown in FIG. 12, the graphite heat spreader 1400 also includes a first patterned heat spreader portion 1444, a second heat spreader portion 1448 (e.g., solid portion without any slots/slits/gaps, etc.), and a third flexible heat spreader portion 1452 (e.g., integrally formed living hinge, etc.). The third flexible heat spreader portion 1452 extends between and thermally couples/connecting the first patterned heat spreader portion 1444 with the second heat spreader portion 1448.

[0099] The first patterned heat spreader portion 1444 includes a pattern defined by a plurality of strips, pieces, areas of the heat spreading material 1404 that are spaced apart from each other by gaps, slots, slits, or areas devoid of the heat spreading material 1408. In this exemplary embodiment, the areas of heat spreading material 1404 and the areas devoid of heat spreading material 1408 may generally define a starburst pattern in which the areas 1404, 1408 radiate or extend linearly outwardly from a generally center location, hub, or opening 1446 of the first patterned heat spreader portion 1444. As another example, the areas of heat spreading material 1404 and the areas devoid of heat spreading material 1408 may generally define a spoked pattern in which the areas 1404, 1408 extend linearly outwardly from the generally center location, hub, or opening 1446 of the first patterned heat spreader portion 1444.

[00100] In this exemplary embodiment, the gaps, slots, slits, or areas devoid of heat spreading material 1408 extend through and into the opening 1446, such that the gaps, slots, slits, or areas devoid of heat spreading material 1208 are open ended. Alteratively, one or more of the gaps, slots, slits, or areas devoid of heat spreading material 1208 may be closed ended on each end. [00101] As shown in FIG. 14, the first pattered heat spreader portion 1444 is configured to have a shape (e.g., an outer perimeter, etc.) and size that substantially matches or corresponds to the shape and size of the support member 1256 (FIG. 13), which is above the coils 1232. The first patterned heat spreader portion 1444 may be sized to substantially cover an entire upper surface of the support member 1256 over the coils 1232 as shown in FIG. 14.

[00102] As shown in FIG. 15, the second heat spreader portion 1448 is configured to have a shape (e.g., an outer perimeter, etc.) and size that substantially matches or corresponds to the shape and size of the heat sink 1260 (FIG. 13), which is below the coils 1232. The second heat spreader portion 1448 may be disposed along and/or in direct thermal contact with the heat sink 1260.

[00103] The third heat spreader portion 1452 may comprise a flexible member (e.g., living hinge, etc.) that is integrally formed along with the first and second heat spreader portions 1444, 1448 from a single sheet of heat spreading material (e.g., a graphite sheet, copper sheet, etc.). The third heat spreader portion 1452 is sufficiently flexible to be flexed or wrapped around and extend across an edge portion of the assembly as shown in FIG. 15. With this flexibility, the third heat spreader portion 1452 is able to thermally couple/connect the first and second heat spreader portions 1444, 1448 even when they are disposed along opposite first and second sides (e.g., upper and lower sides, etc.) of the coils 1232.

[00104] Accordingly, the heat spreader 1400 is configured to be operable for transferring heat from the coils 1232 to the heat sink 1260 via a thermally conductive heat path cooperatively defined by the first patterned heat spreader portion 1444, the third flexible heat spreader portion 1452, and the second heat spreader portion 1448.

[00105] FIGS. 16 and 17 illustrate an exemplary embodiment of a copper heat spreader 1600 installed relative to the wireless charger coils 1232 shown in FIG. 13 for spreading heat from the wireless charger coils 1232. Similar to the heat spreader 1400 shown in FIG. 14, the copper heat spreader 1600 also includes a first pattered heat spreader portion 1644, a second heat spreader portion 1648 (e.g., solid portion without any slots/slits/gaps, etc.), and a third flexible heat spreader portion 1652 (e.g., integrally formed living hinge, etc.). [00106] The first patterned heat spreader portion 1644 includes a pattern defined by a plurality of strips, pieces, areas of the heat spreading material 1604 that are spaced apart from each other by gaps, slots, slits, or areas devoid of the heat spreading material 1608. The third flexible heat spreader portion 1652 extends between and thermally couples/connecting the first pattered heat spreader portion 1644 with the second heat spreader portion 1648. Other than being made of copper instead of graphite, the heat spreader 1600 may comprise features corresponding and/or substantially identical to corresponding features of the heat spreader 1400 (FIGS. 14 and 15).

[00107] FIGS. 18 through 20 illustrate exemplary embodiments of heat spreaders 1800, 1900, and 2000 installed relative to the wireless charger coils 1232 shown in FIG. 21 for spreading heat from the wireless charger coils 1232. The heat spreaders 1800, 1900, 2000 may comprise features corresponding and/or substantially identical to corresponding features of the heat spreader 1400 (FIGS. 14 and 15) and/or heat spreader 1600 (FIGS. 16 and 17). As shown by a comparison of FIGS. 18, 19, and 20, the size of the opening 1846, 1946, and 2046 may vary in exemplary embodiments.

[00108] FIGS. 22 and 23 include wireless charging test results for six test specimens or samples. Samples #2 and #5 included graphite heat spreaders (e.g., 1400 (HGS. 14 and 15), etc.) according to exemplary embodiments. Samples #1, #2, and #3 included an aluminum plate (e.g., 1256 (FIG. 13), etc.) and an EMI shielding can (e.g., 1260 (FIG. 13), etc.). Samples #4, #5, and #6 included an EMI shielding can but not the aluminum plate. For samples #3 and #6, a copper sheet was removed to allow the wireless charging.

[00109] As shown by the results in FIG. 22, the graphite heat spreaders used in samples #2 and #5 significantly improved the quick charge time (e.g., to greater than 3500 seconds, etc.) as compared to samples #1, #3, #4, and #6.

[00110] As shown by the results in FIG. 23, samples #2 and #5 including the graphite heat spreaders (e.g., 1400 (FIGS. 14 and 15), etc.) had the best thermal performance. For example, the temperature remained below 44 °C for sample #2, which included an exemplary embodiment of a graphite heat spreader (e.g., 1400 (FIGS. 14 and 15), etc.), an aluminum plate, and an EMI shielding can. As another example, the temperature remained below 46 °C for sample #5, which included an exemplary embodiment of a graphite heat spreader (e.g., 1400 (FIGS. 14 and 15), etc.) and an EMI shielding can but not the aluminum plate.

[00111] FIG. 24 illustrates exemplary embodiments of patterned heat spreaders 2400, 2403, 800, and 2405 having different example patterns, respectively, parallel cut with 2-fold symmetry, two parallel-cut layers 90-degree overlay, quad cut (4-fold symmetry), and radiating pattern cut. As shown in FIG. 24, the patterned graphite heat spreader 2400 includes a patter defined by a plurality of strips 2404 (broadly, pieces or portions) spaced apart from each other by gaps, slots, or slits 2408.

[00112] FIG. 25 illustrates an exemplary transmit (Tx) device 2502 (e.g., wireless charger, etc.) and an exemplary receive (Rx) device 2570 (e.g., smartphone, etc.) that include patterned heat spreaders according to exemplary embodiments of the present disclosure.

[00113] The transmit (Tx) device 2502 may comprise a wireless charger or other device. The transmit (Tx) device 2502 includes a patterned heat spreader 2500, coils 2532, a ferrite or magnetic sheet 2536, an aluminum plate 2556, a heat sink 2560 (e.g., aluminum heat sink, etc.), an enclosure 2568.

[00114] The receive (Rx) device 2570 may comprise a smartphone or other device. The receive (Rx) device 2570 includes a patterned heat spreader 2572, a coil 2574, a magnetic sheet 2576, a battery 2578, a printed circuit board (PCB) 2580, and an enclosure 2582. Also shown in FIG. 25 is a hot spot 2584 along the PCB 2580 from which heat may be transferred to and spread by the patterned heat spreader 2572.

[00115] Temperature sensors for thermal throttle may be located in the smartphone (broadly, receive (Rx) device). Therefore, the patterned heat spreader 2572 (e.g., patterned graphite sheet, etc.) may be positioned within the smartphone to spread and/or transfer heat in a direction from the smartphone’s back surface towards the wireless charger (broadly, transmit (Tx) device). Improved performance may be achieved by maintaining the transmit (Tx) device temperature low and by transferring heat from the receive (Rx) device to the transmit (Tx) device to maintain the receive (Rx) device temperature low. In turn, this may also help prevent ferrite plate cracks from thermal grading. [00116] FIG. 26 illustrates the exemplary transmit (Tx) device 2502 (e.g., wireless charger, etc.) shown in FIG. 25 and an exemplary patterned heat spreader 2600 that may be used in the transmit (Tx) device 2502. The patterned heat spreader 2600 may be integrated with a wireless charging module. The patterned heat spreader 2600 may be configured (e.g., cut narrow slits/slots in a graphite sheet, etc.) to prevent eddy currents due to the magnetic field from the coils 2532. The patterned heat spreader 2600 may be used to transfer heat from a front portion of the transmit (Tx) device 2502 to the heat sink 2560, which may be generally located along the back of the enclosure 2568. In some exemplary embodiments, thermally-conductive plastic may be used with a patterned graphite heat spreader to thereby provide a multifunctional system (MFS) assembly.

[00117] Similar to the heat spreader 1200 (FIG. 12) and heat spreader 1400 (FIG. 14), the pattered heat spreader 2600 also includes a first patterned heat spreader portion 2644, a second heat spreader portion 2648 (e.g., solid portion without any slots/slits/gaps, etc.), and a third flexible heat spreader portion 2652 (e.g., integrally formed living hinge, etc.). The third flexible heat spreader portion 2652 extends between and thermally couples/connecting the first patterned heat spreader portion 2644 with the second heat spreader portion 2648.

[00118] The third heat spreader portion 2652 has sufficient length to extend across the distance or gap defined between the front of the enclosure 2568 and heat sink 2560. The third heat spreader portion 2652 is also sufficiently flexible to be flexed or wrapped around the end portions of the ferrite 2536 and aluminum plate 2556. With this length and flexibility, the third heat spreader portion 2652 is able to thermally couple/connect the first and second heat spreader portions 2644, 2648 even when they are disposed along opposite first and second sides (e.g., upper and lower sides, etc.) of the coils 2532.

[00119] The first patterned heat spreader portion 2644 includes a pattern defined by a plurality of strips, pieces, or areas of the heat spreading material that are spaced apart from each other by gaps, slots, slits, or areas devoid of the heat spreading material 2608. In this exemplary embodiment, the areas of heat spreading material 2604 and the areas devoid of heat spreading material 2608 may generally define a starburst patter in which the areas 2604, 2608 radiate or extend linearly outwardly from a generally center location of the first patterned heat spreader portion 2644. As another example, the areas of heat spreading material 2604 and the areas devoid of heat spreading material 2608 may generally define a spoked pattern in which the areas 2604, 2608 extend linearly outwardly from the generally center location or hub of the first patterned heat spreader portion 2644.

[00120] In an exemplary embodiment, the patterned heat spreader 2600 may be integrally formed (e.g., via laser cutting, etc.) from a same single sheet of natural and/or synthetic graphite or other heat spreading material (e.g., an aluminum sheet, aluminum die casting, copper sheet, boron nitride sheet, electrically-conductive sheet, electrically- conductive tape, electrically-conductive adhesive, etc.). For example, the strips, pieces, areas of the heat spreading material 2604 may be integrally formed from a same single sheet of synthetic or natural graphite. The gaps, slots, slits, or areas devoid of heat spreading material 2608 may be defined by areas from which portions of the graphite sheet (broadly, heat spreading material) have been removed (e.g., via laser cutting, etching, an automated material removal process, etc.). For example, the gaps, slots, slits, or areas devoid of heat spreading material 2608 may comprise relatively narrow slots or air gaps that are laser cut into the graphite sheet. The gaps, slots, slits, or areas 2608 are devoid of the electrically-conductive graphite and instead include air or other dielectric material. The air or other dielectric material within the gaps, slots, slits, or areas 2608 help to prevent an eddy current from being induced in the first pattered heat spreader portion 2644.

[00121] In exemplary embodiments, the gaps, slots, slits, or areas 2608 may include or be provided with (e.g., filled with, have dispensed therein, etc.) an electrical non-conductor or dielectric material in addition to or as an alternative to air. For example, the gaps, slots, slits, or areas 2608 may include or be provided with plastic or other dielectric material (e.g., dielectric material dispensed via a nozzle into the gaps, etc.) for improved mechanical strength and/or to form part of an enclosure or housing. Or, for example, the gaps, slots, slits, or areas 2608 may include or be provided with a thermally- conductive dielectric thermal interface material for improved thermal performance and heat transfer, e.g., enhanced in-plane heat spreading in the X-Y direction laterally away from a coil(s), etc. As yet another example, the gaps, slots, slits, or areas 2608 may be filled or include dielectric material such that the slots, strips, pieces, or areas of heat spreading material 2604 and the dielectric material within the gaps, slots, slits, or areas 2608 have a unitary, monolithic, or one-piece construction. In this latter example, the combination of the strips, pieces, or areas of heat spreading material 2604 and the dielectric material within the gaps, slots, slits, or areas 2608 may be configured for use as a multifunctional product, e.g., a cover or enclosure having heat spreading functionality, etc.

[00122] FIG. 27 illustrates the exemplary receive (Rx) device 2570 (e.g., smartphone, etc.) shown in FIG. 25 that includes the patterned heat spreader 2572. The patterned heat spreader 2572 may comprise the patterned heat spreader 500 (FIG. 5), patterned heat spreader 2400 (FIG. 24), etc.

[00123] As shown in FIG. 27, the patterned heat spreader 2572 may be used inside the smartphone 2570 (broadly, receive (Rx) device). The patterned heat spreader 2572 may be configured (e.g., cut narrow slits/slots in a graphite sheet, etc.) to prevent eddy currents due to the magnetic field from the coil 2574. The patterned heat spreader 2572 may be used to spread heat from the PCB 2580 and/or coil 2574 generally across an inner surface of the enclosure 2582.

[00124] FIG. 28 illustrates a standalone heat spreader 2886 including a patterned heat spreader 2800 according to an exemplary embodiment of the present disclosure. As shown in FIG. 28, the standalone heat spreader 2886 include heat sinks 2888 (e.g., finned heat sinks, etc.) and a protective layer 2890 along opposite sides of the heat spreader 2800.

[00125] The heat sinks 2886 may be positioned at (e.g., thermally coupled to, etc.) opposing ends of the patterned heat spreader 2800. The protective layer 2890 may be configured to provide scratch protection to the patterned heat spreader 2800 (e.g., natural and/or synthetic graphite, etc.), such as when the smartphone 2892 (broadly, receive (Rx) device) is placed on and/or slides along the standalone heat spreader 2886. The protective layer 2890 may comprise thermally-conductive plastic, non-conductive plastic, etc. For example, a patterned graphite sheet may be integrated with a plastic finish layer for scratch protection.

[00126] The standalone heat spreader 2886 may be configured for use as a device case (e.g., smartphone case, etc.) or a cooling pad for a smartphone. Passive cooling or active cooling may be provided, e.g., attached to no slits/slots region at two ends of the patterned heat spreader 2800, etc. The smartphone 2892 may be positioned on the standalone heat spreader 2886 at about a center region of the patterned heat spreader 2800 which has the patter of cuts, slits, slots, or areas 2804 devoid of heat spreader material. In which case, heat generated from smartphone 2892 will spread from the center region of the pattered heat spreader 2800 towards the regions at the two ends of the pattered heat spreader 2800 where heat sinks 2888 are located.

[00127] Example electrical specifications that may be used for 15 Watt power receiver coil(s) in exemplary embodiments include inductance in microhenries (μΗ +/- 10 %) within a range from 9 μH to 11 μH with a nominal value of 10 μH, a maximum DC resistance (DCR) in milliohms (ιηΩ) of 160 μH or 180 μH, and rated current of 2 amps

(A).

[00128] In exemplary embodiments, laser cutting may be used to define relatively thin strips or portions of heat spreading material. There may be connections between the strips of heat spreading material, such as along the outer perimeter and/or center for structure integrity, etc. The connections may be trimmed off or otherwise removed, such as after lamination or otherwise supporting the strips or portions of heat spreading material with support film.

[00129] In exemplary embodiments, a patterned heat spreader may be configured to have a graphite skin depth of about 1 mm, electrical conductivity of 2000 S/cm, and resistivity of 50 micron Ohm cm at 15 watts and 120 kHz frequency.

[00130] Instead of a single sheet of heat spreading material, exemplary embodiments disclosed herein may include multiple strips (broadly, portions or pieces) of heat spreading material spaced apart with gaps between adjacent strips. The strips and/or the gaps may be oriented generally perpendicular or orthogonal to at least a portion of a coil(s) and to the eddy current which would otherwise be present if the gaps were not present and which eddy current might otherwise interfere with the magnetic field, interfere with the wireless charging, generate heat, etc. For example, the strips and gaps may be configured to be orthogonal to intersection points (e.g., in a tip down x-ray view, etc.) of the coil(s).

[00131] In exemplary embodiments, a heat spreader may be configured to allow a maximum magnetic field passage of no more than about 20 Watts and/or a have at least about 0.1 Watts heat spreading capability. [00132] The heat spreaders disclosed herein may also be used with various coil configurations including spiral coils, rectangular coils, square coils, round coils, circular coils, oval coils, elliptical coils, angular coils, combinations thereof, etc. Accordingly, aspects of the present disclosure should not be limited to any one specific coil configuration.

[00133] In exemplary embodiments, the heat spreader may be structured or patterned in various ways to have gaps or areas devoid of the heat spreading material that would pass magnetic fields and inhibit eddy currents. For example, strips of heat spreading material and the gaps therebetween may define various patters and shapes for a heat spreader, such as symmetrical patters, asymmetrical patters, spiral patters, triangular shapes, starburst patters, radiating patters, spoked patters, parallel cut with 2-fold symmetry, two parallel-cut layers 90-degree overlay, quad cut (4-fold symmetry), among other patters and shapes that provide improved heat performance and mitigate Q degradation as compared to a full or solid sheet of the heat spreading material, etc.

[00134] In exemplary embodiments, the ratio of strip width/area to gap width/area may be predetermined to be within a range from about 99 to about 1. The strips and the gaps may have various shapes, such as quadrilateral, symmetrical shapes, asymmetrical shapes, rectangles, parallelograms, polygons, or the like with parallel edges, pie wedges, triangles, or the like with non-parallel edges.

[00135] In some exemplary embodiments, one or more thermal interface materials may be used with a pattered heat spreader. Example thermal interface materials that may be used in exemplary embodiments include thermal gap fillers (e.g., silicone based thermal gap fillers, non-silicone based thermal gap fillers, etc.), thermal phase change materials, thermally-conductive EMI absorbers or hybrid thermal/EMI absorbers, thermal putties, thermal pads, thermal greases, etc.

[00136] In some exemplary embodiments, the thermal interface material (TIM) may include an elastomer matrix (e.g., silicone elastomer matrix, etc.), non-silicone matrix, etc. The elastomer or other matrix of the TIM may be filled with one or more suitable thermally-conductive fillers, such as zinc oxide, boron nitride, alumina, silicon nitride, aluminum nitride, iron, metallic oxides, graphite, silver, copper, ceramics, combinations thereof, etc. In addition, exemplary embodiments may also include different grades (e.g., different sizes, different purities, different shapes, etc.) of the same (or different) thermally conductive fillers. For example, a thermal interface material may include two different sizes of boron nitride. Or, for example, a thermal interface material may include multiple grades of aluminum and/or multiple grades of alumina where the grades have different mean particle sizes and different particle size ranges. By varying the types and grades of thermally-conductive fillers, the final characteristics of the thermal interface material (e.g., thermal conductivity, cost, hardness, etc.) may be varied as desired.

[00137] Other suitable fillers and/or additives may also be added to a thermal interface material to achieve various desired outcomes (e.g., a thixotropic and/or dispensable putty, etc.). Examples of other fillers that may be added include pigments, plasticizers, process aids, flame retardants, extenders, electromagnetic interface (EMI) or microwave absorbers, electrically-conductive fillers, etc.

[00138] The TIM may include a thermal interface material from Laird Technologies, such as any one or more of the Tputty™ 502 series thermal gap fillers, Tflex™ series gap fillers (e.g., Tflex™ 300 series thermal gap filler materials, Tflex™ 600 series thermal gap filler materials, Tflex™ 700 series thermal gap filler materials, etc.), Tpcm™ series thermal phase change materials (e.g., Tpcm™ 580 series phase change materials, Tpcm™ 780 series phase change materials, Tpcm™ 900 series phase change materials etc.), Tpli™ series gap fillers (e.g., Tpli™200 series gap fillers, etc.), IceKap TM series thermal interface materials, Tmate™ 2900 series reusable phase change materials, Tgon™ 800 series thermal interface materials or natural graphite sheets, Tgon™ 8000 series thermal interface materials or graphite sheets, Tgon™ 9000 series graphite sheets (e.g., Tgon™ 9017, 9025, 9040, 9070, 9100, etc.), Tgon™ encapsulate or potting compounds, such as Tgon™ 455-18SH, other graphite sheet materials, etc.

[00139] In some exemplary embodiments, the TIM may comprise a metal foil, a multi-laminate structure, such as a multi-laminate structure of metal and plastic, a multilaminate structure of metal and graphite, or a multi-laminate structure of metal, graphite, and plastic.

[00140] In an exemplary embodiment, the TIM comprises a two-part dispensable TIM (e.g., Tflex™ CR200, etc.) having a thermal conductivity of about 2 W/mK. In another exemplary embodiment, the TIM comprises a thermal phase change material (e.g., Tpcm™ 780 series phase change materials, etc.) having a thermal conductivity of about 5.4 W/mK. In another exemplary embodiment, the TIM comprises a non-silicone thin gap filler (e.g., Slim TIM™ 10000, etc.) having a thermal conductivity of about 5.5 W/mK.

[00141] In some exemplary embodiments, the TIM may comprise a compliant gap filler having high thermal conductivity. By way of example, the TIM may comprise a thermal interface material of Laird, such as one or more of Tflex™ 200, Tflex™ CR200, Tflex™ HR200, Tflex™ 300, Tflex™ 300TG, Tflex™ HR400, Tflex™ 500, Tflex™ 600, Tflex™ HR600, Tflex™ SF600, Tflex™ 700, and/or Tflex™ SF800 thermal gap fillers.

[00142] In some exemplary embodiments, the TIM may comprise a soft and compliant gap filler having high thermal conductivity. The TIM may comprise an elastomer and/or ceramic particles, metal particles, ferrite EMI/RFI absorbing particles, metal or fiberglass meshes in a base of rubber, gel, or wax, etc. The TIM may include compliant or conformable silicone pads, non-silicone based materials (e.g., non-silicone based gap filler materials, thermoplastic and/or thermoset polymeric, elastomeric materials, etc.), silk screened materials, polyurethane foams or gels, thermally-conductive additives, etc. The TIM may be configured to have sufficient conformability, compliability, and/or softness (e.g., without having to undergo a phase change or reflow, etc.) to adjust for tolerance or gaps by deflecting at low temperatures (e.g., room temperature of 20 °C to 25 °C, etc.) and/or to allow the thermal interface materials to closely conform (e.g., in a relatively close fitting and encapsulating manner, etc.) to a mating surface when placed in contact with (e.g., compressed against, etc.) the mating surface, including a non-flat, curved, or uneven mating surface.

[00143] Exemplary embodiments may include one or more thermal interface materials having a high thermal conductivity (e.g., 1 W/mK (watts per meter per Kelvin), 2 W/mK, 3 W/mK, 4 W/mK, 5 W/mK, 5.4 W/mK, 5.5 W/mK, 6W/mK, 7 W/mK, 8 W/mK, etc.) depending on the particular materials used to make the thermal interface material and loading percentage of the thermally conductive filler, if any. These thermal conductivities are only examples as other embodiments may include a thermal interface material with a thermal conductivity higher than 8 W/mK, less than 1 W/mK, or other values and ranges between 1 and 8 W/mK. Accordingly, aspects of the present disclosure should not be limited to use with any particular thermal interface material as exemplary embodiments may include a wide range of thermal interface materials.

[00144] In some exemplary embodiments, the thermal interface material may be configured for both thermal management and EMI mitigation (e.g., a thermally-conductive microwave/RF/EMI absorber, etc.). In such exemplary embodiments, the thermal interface material may include EMI absorbing material (e.g., EMI absorbing particles, fillers, flakes, etc.), such as silicon carbide, carbonyl iron, alumina, manganese zinc (MnZn) ferrite, SENDUST (an alloy containing about 85% iron, 9.5% silicon and 5.5% aluminum), permalloy (an alloy containing about 20% iron and 80% nickel), iron silicide, iron-chrome compounds, metallic silver, nickel-based alloys and powders, chrome alloys, combinations thereof, etc.

[00145] Exemplary embodiments disclosed herein may be used in various wireless charging and/or inductive power transfer applications for a wide range of devices. For example, exemplary embodiments have been described herein in the context of wireless charging of smartphones. But aspects of the present disclosure should not be limited solely to wireless charging applications for smartphones. Instead, aspects of the present disclosure may be also used with wireless charging and/or inductive power transfer for a wide range of devices, including consumer electronics, home appliances (e.g., blenders, toasters, etc.), etc.

[00146] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well- known processes, well-known device structures, and well-known technologies are not described in detail. In addition, advantages and improvements that may be achieved with one or more exemplary embodiments of the present disclosure are provided for purpose of illustration only and do not limit the scope of the present disclosure, as exemplary embodiments disclosed herein may provide all or none of the above mentioned advantages and improvements and still fall within the scope of the present disclosure.

[00147] Specific dimensions, specific materials, and/or specific shapes disclosed herein are example in nature and do not limit the scope of the present disclosure. The disclosure herein of particular values and particular ranges of values for given parameters are not exclusive of other values and ranges of values that may be useful in one or more of the examples disclosed herein. Moreover, it is envisioned that any two particular values for a specific parameter stated herein may define the endpoints of a range of values that may be suitable for the given parameter (the disclosure of a first value and a second value for a given parameter can be interpreted as disclosing that any value between the first and second values could also be employed for the given parameter). Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges.

[00148] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. For example, when permissive phrases, such as “may comprise”, “may include”, and the like, are used herein, at least one embodiment comprises or includes the feature(s). As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alterative steps may be employed.

[00149] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[00150] The term “about” when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms “generally,” “about,” and “substantially,” may be used herein to mean within manufacturing tolerances. Whether or not modified by the term “about,” the claims include equivalents to the quantities.

[00151] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[00152] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[00153] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.