Patent Publication Number: US-2018054077-A1

Title: Shield for a wirelessly charged electronic device

Description:
FIELD 
     The described embodiments relate generally to a wirelessly charged electronic device that includes a touch sensitive user interface screen. More particularly, the present invention relates to a wirelessly charged electronic device that includes an electrically conductive shield to shield the touch sensitive user interface from electromagnetic interference generated during inductive charging of the electronic device. 
     BACKGROUND 
     Mobile devices such as smart phones, tablets, smart watches, and the like can be configured for wireless charging. Such mobile devices are often sold along with a wireless charging device (e.g., a charging station) that is specifically configured for charging the mobile device. During wireless charging users may wish to communicate with the mobile device by interacting with its touch sensitive user interface. 
     SUMMARY 
     Some embodiments of the present disclosure relate to portable electronic devices that are inductively charged and have one or more electrically conductive shields configured to attenuate electromagnetic noise generated during a charging event. Some embodiments relate to electrically conductive shields that are specifically configured to attenuate electromagnetic noise that interferes with a touch sensitive user interface on the portable electronic device. 
     In some embodiments an electronic device comprises an housing having a charging surface through which electromagnetic energy can be transferred and an inductive charging receive coil disposed within the electronic device adjacent to the charging surface and configured to receive electromagnetic energy through the charging surface. An electrically conductive shield is disposed between the inductive charging receive coil and the charging surface and is electrically coupled to a ground potential of the electronic device. 
     In some embodiments the electrically conductive shield is located on an interior surface of the housing. In various embodiments the electrically conductive shield has a sheet resistance between 2 ohm/square and 15 kiloohm/square. In some embodiments the electrically conductive shield comprises a layer of electrically conductive carbon. In various embodiments the layer of electrically conductive carbon has a sheet resistance between 2 ohm/square and 15 kiloohm/square and is between 5 to 50 microns thick. 
     In some embodiments the housing comprises glass. In various embodiments the electronic device further comprises a touch sensitive user interface and the electrically conductive shield is positioned and configured to shield the touch sensitive user interface from electromagnetic interference generated during inductive charging of the electronic device. In various embodiments one or more alignment features enable the charging surface to be properly aligned with a wireless charger for a charging event. In some embodiments the one or more alignment features include one or more magnets that assist in aligning the charging surface to the wireless charger. 
     In some embodiments an inductively charged electronic device comprises a housing having a charging surface through which electromagnetic energy can be transferred, the charging surface positioned on a first exterior surface of the housing. A cover glass is coupled to the housing and defines a second exterior surface of the housing opposite the first exterior surface. A display is positioned within the housing adjacent to and visible through the cover glass. An inductive charging receive coil positioned within the housing and is configured to receive electromagnetic charging energy through the charging surface and an electrically conductive shield is positioned between the charging surface and the inductive charging receive coil, the electrically conductive shield coupled to a ground potential of the electronic device and configured to attenuate electromagnetic noise generated during inductive charging of the electronic device. 
     In some embodiments the electrically conductive shield is disposed on an interior surface of the housing. In various embodiments the cover glass and the display are a portion of a touch sensitive user interface. In some embodiments the housing comprises the cover glass, a metal frame and a back crystal, wherein the electrically conductive shield is formed on a portion of the back crystal. In various embodiments the electrically conductive shield comprises a layer of electrically conductive carbon. 
     In some embodiments the layer of electrically conductive carbon has a sheet resistance between 2 ohm/square and 15 kiloohm/square and is between 5 to 50 microns thick. In various embodiments a conductor is electrically coupled to the electrically conductive shield with an electrically conductive epoxy and couples the electrically conductive shield to the ground potential. In some embodiments at least a portion of the housing is made from a glass material. 
     In some embodiments an electronic system comprises an inductively charged electronic device including a touch sensitive user interface, an housing through which electromagnetic energy can be transferred, and an inductive charging receive coil disposed within the electronic device and configured to receive electromagnetic energy through the housing. An inductive charging station has an inductive charging transmit coil configured to transmit electromagnetic energy to the inductive charging receive coil of the electronic device, and an electrically conductive shield is disposed between the inductive charging receive coil and the inductive charging transmit coil and configured to shield the touch sensitive user interface from electromagnetic interference generated during inductive charging of the electronic device. 
     In some embodiments the electrically conductive shield is disposed on the electronic device. In various embodiments the electrically conductive shield is disposed on the inductive charging station. 
     To better understand the nature and advantages of the present disclosure, reference should be made to the following description and the accompanying figures. It is to be understood, however, that each of the figures is provided for the purpose of illustration only and is not intended as a definition of the limits of the scope of the present disclosure. Also, as a general rule, and unless it is evident to the contrary from the description, where elements in different figures use identical reference numbers, the elements are generally either identical or at least similar in function or purpose. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an inductively charged electronic device on a charging station according to an embodiment of the disclosure; 
         FIG. 2  is a cross-sectional view of the electronic device and the charging station shown in  FIG. 1 ; 
         FIG. 3  is a close-up view of a portion of the cross-section shown in  FIG. 2 ; 
         FIGS. 4A and 4B  are perspective views of an inductively charged watch according to an embodiment of the disclosure; 
         FIG. 4C  is a perspective view of the inductively charged watch illustrated in  FIGS. 4A and 4B  disposed on a charging station; 
         FIG. 5  is an exploded view of a back crystal with an electrically conductive shield on an inner surface and an inductive charging receive coil of the watch illustrated in  FIGS. 4A-4C ; 
         FIG. 6  is a perspective view of a back crystal of the watch illustrated in  FIGS. 4A-4C  with an electrically conductive shield on an inner surface; 
         FIG. 7  is a perspective view of a back crystal of the watch illustrated in  FIGS. 4A-4C  with an electrically conductive shield on an inner surface; 
         FIGS. 8-11  are cross-sections showing methods of coupling a conductor to an electrically conductive shield according to embodiments of the disclosure; and 
         FIG. 12  is a system schematic of an inductively charged electronic device and a docking station according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments of the present disclosure relate to an inductively (i.e., wirelessly) charged electronic device that has a touch sensitive display for interaction with a user. During a charge event a user may wish to communicate with the electronic device using the touch sensitive display. An electrically conductive shield is positioned within the electronic device to attenuate electromagnetic noise generated during inductive charging of the electronic device so the electromagnetic noise does not interfere with the performance of the touch sensitive display. 
     While the present disclosure can be useful for a wide variety of configurations, some embodiments of the disclosure are particularly useful for relatively compact electronic devices that have inductive charging coils located relatively close to a touch sensitive display, as described in more detail below. 
     For example, in some embodiments a portable electronic device is placed on a charging station for a charging event. An inductive charging receive coil within the portable electronic device receives electromagnetic charging energy from the charging station through a charging surface. An electrically conductive shield is coupled to a ground of the portable electronic device and is disposed between the inductive charging coil and the charging surface. The electrically conductive shield is configured to attenuate electromagnetic noise generated during a charging event so it does not interfere with a user&#39;s operation of the touch sensitive display on the portable electronic device. 
     In another example the electrically conductive shield is formed from an electrically conductive layer of carbon particles adhered to a rear housing of the electronic device. One or more conductors are coupled to the electrically conductive shield with an electrically conductive epoxy and couple the electrically conductive shield to ground of the portable electronic device. In a further example, the rear housing and charging surface of the portable electronic device is a back crystal of a watch and is made of a glass material. 
     In order to better appreciate the features and aspects of electrically conductive shields for electronic devices according to the present disclosure, further context for the disclosure is provided in the following section by discussing one particular implementation of an electronic device according to embodiments of the present disclosure. These embodiments are for example only and other embodiments can be employed in other electronic devices such as, but not limited to computers, media players and other electronic devices. 
       FIG. 1  is a front isometric view illustrating a system  100  that enables a portable electronic device to be wirelessly charged. System  100  may include a portable electronic device  110 , such as a wearable electronic device, and a wireless charger  120 , such as a docking station. Although  FIG. 1  illustrates portable electronic device  110  and wireless charger  120  as specific devices having particular shapes and sizes relative to each other, the illustrated devices merely serve as an example. In various implementations, either portable electronic device  110  or wireless charger  120  may be a variety of different types of electronic devices having a variety of different shapes and/or sizes provided that wireless charger  120  is configured to wirelessly charge a battery or other power source within portable electronic device  110 . For example, portable electronic device  110  may be a tablet computer, a mobile computing device, a smart phone, a cellular telephone, a digital media player, or a variety of different types of wearable electronic devices. One example of a wearable device that portable electronic device  120  may represent can be worn on a user&#39;s wrist like a watch and includes a display to indicate the date and time, but can also do much more than act as a simple time piece. For example, the device may include may also include accelerometers and one or more sensors that enable a user to track fitness activities and health-related characteristics, such as heart rate, blood pressure, and body temperature, among other information. Similarly, wireless charger  120  may be a stand-alone dock or may be incorporated into another electronic device, such as a stereo receiver, a clock radio, or other device. 
     As illustrated in  FIG. 1 , portable electronic device  110  includes a charging surface  112  that is operable to contact a charging face  122  of wireless charger  120 . In some embodiments, charging surface  112  and charging face  122  form a sliding interface between portable electronic device  110  and wireless charger  120 . As such, the two devices may be positionable with respect to each other in one or more directions. 
     Wireless charger  120  includes a power transmitting component (not shown) that is positioned adjacent to charging face  122  of housing  126 . The power transmitting component can wirelessly transmit power across charging face  122  to portable electronic device  110  to charge one or more batteries or other power sources within the portable electronic device. In some embodiments charging face  122  can have a concave shape that matches a convex shape of charging surface  112  of portable electronic device  110 . In order to provide power to the power transmitting component, wireless charger  120  can receive power from an external source through a cable  124  or other connection or can include its own power source, such as a battery (not shown). 
     Portable electronic device  110  has a touch sensitive user interface  114  or other medium through which information, such as the date and time, phone calls, text messages, emails and other alerts may be displayed and can be disposed on a second exterior surface  130 . In various embodiments an inductive charging receive coil (not shown) is positioned within portable electronic device  110  and configured to receive electromagnetic charging energy through charging surface  112 . An electrically conductive shield (not shown) can be positioned between charging surface  112  and the inductive charging receive coil to attenuate electromagnetic noise generated during inductive charging of the electronic device, as described in more detail below. In some embodiments the reduced electromagnetic noise may make touch sensitive user interface  114  easier for a user to interact with. 
     Now referring to  FIG. 2 , a cross-section A-A through a portion of portable electronic device  110  and wireless charger  120  illustrated in  FIG. 1  is shown. A housing  205  of portable electronic device  110  has a first exterior surface  210  that includes charging surface  112  shown in  FIG. 2  as positioned adjacent to and abutting a charging face  122  of wireless charger  120 . In some embodiments at least a portion of housing  205  may be made from zirconia, a glass material and/or a plastic. Second exterior surface  130  of housing  205  may be defined by a touch sensitive user interface  114  that can include a cover glass  215  and a display  220 . Display  220  may be positioned within housing  205 , adjacent to and visible through cover glass  215 . In some embodiments a metallic or plastic frame portion of housing  205  can be used to hold cover glass  215  portion of the housing in place. 
     An inductive charging receive coil  230  is positioned within housing  205  of portable electronic device  110  and is configured to receive electromagnetic charging energy through charging surface  112 . An electrically conductive shield  235  is positioned between charging surface  112  and inductive charging receive coil  230 . Electrically conductive shield  235  may be coupled to a ground potential of portable electronic device  110  and configured to attenuate electromagnetic noise generated during inductive charging of the portable electronic device so it does not interfere with the operation of touch sensitive display  114 . 
     Wireless charger  120  has a charger housing  240  with a charging face  122  designed to receive portable electronic device  110 . Wireless charger  120  may have an inductive charging transmit coil  245  configured to transmit electromagnetic energy to inductive charging receive coil  230  of portable electronic device  110 . In some embodiments wireless charger  120  may have one or more alignment features (e.g., magnets) that enable charging surface  112  of portable electronic device  110  to be properly aligned with charging face  122  of the wireless charger for a charging event. 
     Now referring to  FIG. 3  a close up view of area B-B, representing a portion of portable electronic device  110  and wireless charger  120  illustrated in  FIG. 1 , is shown. As shown in  FIG. 3 , electrically conductive shield  235  is positioned between receive coil  230  and an interior surface  305  of housing  205 . In some embodiments electrically conductive shield  235  may be a concentric ring disposed only under receive coil  230 , as shown, however in other embodiments it may have a different shape such as a filled circle or any other two-dimensional shape, as described in more detail below. In some embodiments a conductor  310  can be electrically coupled to electrically conductive shield  235  with an electrically conductive epoxy  315 , however some embodiments may use a different interconnect. Conductor  310  can be coupled to a ground of portable electronic device  110  so electrically conductive shield  235  attenuates electromagnetic energy generated during a charging event to minimize interference with touch sensitive user interface  114  (see  FIG. 2 ). 
     In some embodiments, during a charge event, electrically conductive shield  235  may be designed as a “selective shield” allowing electromagnetic charging energy to be transferred from transmit coil  245  to receive coil  230  while simultaneously attenuating electromagnetic noise that interferes with the operation of touch sensitive user interface  114  (see  FIG. 2 ). For example, in some embodiments touch sensitive user interface  114  may reference a system ground that may be unstable due to electromagnetic noise generated by a charge event. The noise may result in a lack of detection, false detection, inaccuracy in detected position, a jittery display or other unfavorable conditions of touch sensitive user interface  114 . Conductive shield  235  may be configured to reduce the noise on the system ground, improving the function of the touch sensitive user interface  114  while allowing charge energy to be passed to receive coil  230 . 
     In some embodiments it may be desirable to optimize the selective transmittance and shielding properties of electrically conductive shield  235  by tuning the electrical conductivity, the thickness, the geometry and/or the material of the electrically conductive shield as described in more detail below. In one example the sheet resistivity of electrically conductive shield  235  may be reduced to improve its shielding performance while the electrically conductive shield may also be patterned or reduced in thickness to minimize eddy currents that can cause a reduction in inductive charge efficiency. 
     In one embodiment, electrically conductive shield  235  is formed by a layer of conductive carbon that is adhered to an interior surface  305  of housing  205 . In some embodiments the layer of conductive carbon can first be deposited as an ink that is later cured. In some embodiments the layer of conductive carbon has a sheet resistance of 2 kiloohms/square and is between 8-12 microns thick, however it may have other properties and thicknesses as described in more detail below. Some embodiments may use a different material for electrically conductive shield  235 , as also discussed in more detail below. 
     Reference is now made to  FIGS. 4A and 4B , that depict front and rear perspective views of one type of portable electronic device with which embodiments of the electrically conductive shield  235  (see  FIG. 3 ) may be used. As shown, wearable electronic device  400  includes a casing  402  that houses a display  404  and various input devices including a dial  406  and a button  408 . 
     Device  400  may be worn on a user&#39;s wrist and secured thereto by a band  410 . Band  410  includes lugs  412  at opposing ends of the band that fit within respective recesses or apertures  414  of the casing and allow band  410  to be removably attached to casing  402 . Lugs  412  may be part of band  410  or may be separable (and/or separate) from the band. Generally, the lugs may lock into recesses  414  and thereby maintain connection between the band and casing  402 . The user may release a locking mechanism (not shown) to permit the lugs to slide or otherwise move out of the recesses. In some wearable devices, the recesses may be formed in the band and the lugs may be affixed or incorporated into the casing. 
     Casing  402  which may also be referred to as a housing, also houses electronic circuitry (not shown in  FIGS. 4A or 4B ) , including a processor and communication circuitry, along with sensors  422 ,  424  that are exposed on a bottom surface  420  of casing  402 . In some embodiments casing  402  may be made from a metal or plastic and can include a back crystal  490  that may be made from a glass or other material, and a glass display  404  . The circuitry, sensors, display and input devices enable wearable electronic device  400  to perform a variety of functions including, but not limited to: keeping time; monitoring a user&#39;s physiological signals and providing health-related information based on those signals; communicating (in a wired or wireless fashion) with other electronic devices; providing alerts to a user, which may include audio, haptic, visual and/or other sensory output, any or all of which may be synchronized with one another; visually depicting data on a display; gathering data form one or more sensors that may be used to initiate, control, or modify operations of the device; determining a location of a touch on a surface of the device and/or an amount of force exerted on the device, and use either or both as input; accepting voice input to control one or more functions; accepting tactile input to control one or more functions; and so on. 
     A battery (not shown in  FIGS. 4A or 4B ) internal to casing  402  powers wearable electronic device  400 . The battery can be inductively charged by an external power source, such as wireless charger, and wearable electronic device  400  can include circuitry configured to operate as a receiver in a wireless power transfer system as described with respect to  FIGS. 1 and 2 . Bottom surface  420  of electronic device  400  can have a convex shape that enables the surface to facilitate proper alignment to a wireless power transmitter in the wireless charger. Also, while not shown in  FIGS. 4A or 4B , portable electronic device  400  may include one or more magnets or magnetic plates that can further assist in aligning device  400  to the charging surface of a wireless charger. 
       FIG. 4C  is a perspective view of a wireless charger  495  with wrist-worn portable electronic device  400  shown in  FIGS. 4A and 4B  placed on the charger in a charging position. As shown in  FIG. 4C , wrist-worn portable electronic device  400  lies essentially flat across upper surface  496  of charger  495  in the charging position. Bottom surface  420  of device  400  can align with an optional concave charging surface  497  of wireless charger  495  to facilitate proper alignment of the wireless power receiving components within device  400  with the wireless power transmitting components within charger  495 . Additionally, one or more alignment magnets (not shown) can also facilitate proper alignment between the wireless power receiving and transmitting components. 
     A power transmitting coil (not shown) is positioned under charging surface  497  and an alignment magnet (not shown) may be centered within the charging surface. When a portable electronic device is positioned against charging surface  497 , the alignment magnet, which can be in a fixed position within charger  495 , can help center electronic device  400  to the power transmitting coil thus increasing the efficiency of any charging operation. 
     Now referring to  FIG. 5  an exploded top perspective view of back crystal  490  of wearable electronic device  400  and inductive charging receive coil  505  is illustrated. In some embodiments electrically conductive shield  510  is disposed adjacent to and/or adhered to back crystal  490 . Back crystal  490  may have one or more apertures  515  through its thickness that can be used to transmit and receive optical information that can be used for functions, such as, for example a monitoring a user&#39;s physiological signals. 
     In some embodiments electrically conductive shield  510  may be formed on back crystal  490  using an electrically conductive ink, as discussed above. In various embodiments the conductive ink may be silkscreened, pad printed, sprayed or otherwise deposited on back crystal  490  and cured, leaving a layer of electrically conductive carbon. 
     In further embodiments electrically conductive shield  510  may be formed with one or more layers of metal. The following are only examples of metal layers, other combinations, thicknesses and types of metal layers can be used for conductive shield  510  and are within the scope of this disclosure. Some non-limiting example combinations of metal layers are: a first layer of titanium approximately 100 nanometers thick followed by a layer of aluminum approximately 100 nanometers thick followed by an optional added layer of aluminum/titanium nitride that is thick, a single layer of titanium approximately 100 nanometers thick followed by an optional approximately 200 nanometers layer of aluminum/titanium nitride that is approximately 200 nanometers thick, a single layer of titanium approximately 100 nanometers thick or a single layer of tantalum that is approximately 100 nanometers thick. In some embodiments the one or more layers of metal can be sputtered, plated or otherwise deposited on back crystal  490 . 
     In further embodiments electrically conductive shield  510  can be made from an electrically conductive paste combined with a glass frit that is formulated to be fired onto back crystal  490 . The paste may contain silver, gold or any other conductive particles and may be printed or dispensed on back crystal  490 , then fired in place using a furnace. In further embodiments electrically conductive shield  510  may be an electrically conductive label that is adhered to back crystal  490 . 
     In some embodiments electrically conductive shield  510  can be made from a flexible printed circuit material such as, for example a layer of metal sandwiched between layers of an organic material such as polyamide also called a “flex circuit”. 
     In some embodiments where back crystal  490 , is made from a plastic material, electrically conductive shield  510  may be an electrically conductive label that is co-molded with a portion of the back crystal. In further embodiments, laser direct structuring (LDS) along with an associated plating process can be used to define and form electrically conductive shield  510  on back crystal  490 . 
     As discussed above the selective transmittance and shielding properties of electrically conductive shield  510  can be achieved by optimizing the electrical conductivity, the thickness, the geometry and/or the material of the electrically conductive shield. Generally speaking, in some embodiments the material of electrically conductive shield  510  may have a relatively high sheet resistance and be relatively thick and/or have broad coverage on back crystal  490 . In other embodiments the material of electrically conductive shield  510  may have a relatively low sheet resistance and be relatively thin and/or have reduced coverage on back crystal  490 . Those of skill in the art will recognize that myriad variations of material properties and geometries of electrically conductive shield  510  can function as a shield as described herein and are within the scope of this disclosure. 
     In some embodiments electrically conductive shield  510  is designed to have a relatively high sheet resistance of 2 kiloohms/square and is between 8-12 microns thick. In further embodiments the 8-12 micron thick electrically conductive shield may have a sheet resistance between 1 kiloohm/square and 3 kiloohms/square while in various embodiments it may be between 0.5 kiloohms/square and 4 kiloohms/square. In some embodiments the 8-12 micron thick electrically conductive shield  510  may have a sheet resistance between 2 ohms/square and 15 kiloohms/square. 
     In some embodiments electrically conductive shield  510  is designed to have a relatively low sheet resistance of less than 2 ohms/square and may have a thickness between 0.1 to 5 microns, and/or is patterned. In one embodiment electrically conductive shield  510  has a sheet resistance of 0.6 ohms/square, is 1 micron thick and covers a significant portion of back crystal  490 . 
     These are merely examples and as discussed above, depending on the particular geometry of electrically conductive shield  510 , other sheet resistance values and thicknesses may be used to achieve the appropriate shielding and transmittance performance. 
     In some embodiments back crystal  490  may be zirconia, ceramic, a glass or a plastic material. In further embodiments, any material that allows electromagnetic charging energy to pass through it can be used for back crystal  490 . 
     Now referring to  FIGS. 5-7 , a few example geometries of electrically conductive shields are illustrated, however these are for example only and other patterns/geometries of electrically conductive shields are within the scope of this disclosure. For example, in  FIG. 5  electrically conductive shield  510  is in the pattern of a ring having an inner ring diameter  520  and an outer ring diameter  525  that are concentric and similar in size to inner diameter  530  and outer diameter  535  of transmit coil  505  In some embodiments electrically conductive shield  510  may have one or more ground contact areas  540   a ,  540   b  used for securing one or more conductors  310  (see  FIG. 3 ) that are coupled to a ground of the portable electronic device. 
     Now referring to  FIG. 6 , in comparison to the embodiment illustrated in  FIG. 5 , electrically conductive shield  610  covers an entire inner surface of back crystal  490 , except for apertures  515  and middle portion  615  disposed between the apertures. Electrically conductive shield  610  may also have one or more ground contact areas  640   a ,  640   b  used for securing one or more conductors  310  (see  FIG. 3 ) that are coupled to a ground of the portable electronic device. 
     Now referring to  FIG. 7 , electrically conductive shield  710  is similar to electrically conductive shield  510  illustrated in  FIG. 5 , resembling a ring having an outer ring diameter that approximately matches an outer diameter of receive coil  505  (see  FIG. 5 ). However, electrically conductive shield  710  has an inner ring diameter  720  that is greater than inner diameter  530  (see  FIG. 5 ) of transmit coil  505 . Electrically conductive shield  710  may also have one or more gaps  750 . Electrically conductive shield  710  may further have one or more ground contact areas  740  used for securing one or more conductors  310  (see  FIG. 3 ) that are coupled to a ground of the portable electronic device. 
     Now referring to  FIGS. 8-11 , examples of coupling an electrical conductor  310  to an electrically conductive shield  810  are illustrated, however other methods may be used and are within the scope of this disclosure.  FIG. 8  illustrates an electrically conductive shield  810  disposed on an interior surface  815  of a substrate  820 . Substrate  820  can be a housing of an electronic device, a back crystal of an electronic device or a housing of a charger as described herein. In this example, conductor  310  is bonded to electrically conductive shield  810  using an electrically conductive adhesive  820 . Conductor  310  may be a wire, a flexible circuit (e.g., a conductive metal disposed on a flexible polymer), a wirebond, a metallic ribbon or any other type of electrical conductor. Conductive adhesive  820  may be any type of adhesive that is filled with silver, gold or any other electrically conductive material. Conductive adhesive  820  can be used to form an electrical connection between electrically conductive shield  810  and conductor  310 , while also providing a mechanical support structure between the conductor and the electrically conductive shield. An optional bonding material  825  that can be any type of epoxy or adhesive can be disposed over the interconnect region to provide additional structural integrity for the interconnect. 
     Now referring to  FIG. 9 , another example embodiment showing a method of coupling an electrical conductor  310  to an electrically conductive shield  910  is illustrated. In this embodiment, conductor  310  is adhered to interior surface  815  of housing  820  and electrically conductive shield  910  is formed over the conductor. For example, in one embodiment conductor  310  may be a metallic ribbon that is adhered to substrate  820  with an epoxy, then electrically conductive shield  910  is deposited on the substrate and ribbon. Electrically conductive shield  910  is in contact with conductor  310  such that the electrically conductive shield can be grounded by conductor  310 . An optional bonding material  825  that can be any type of epoxy or adhesive can be disposed over the interconnect region to provide additional structural integrity for the interconnect. 
     Now referring to  FIG. 10 , another embodiment showing a method of coupling an electrical conductor  310  to an electrically conductive shield  1010  is illustrated. This embodiment is similar to  FIG. 9 , however in this embodiment conductor  310  is recessed into top surface  825  of substrate  820  such that electrically conductive shield  1010  is substantially planar while being disposed at least partially over the conductor. In some embodiments conductor  310  may be secured to substrate  820  with an adhesive or other method. This embodiment may be useful for forming connections to substrates made from a plastic material where conductor  310  can be easily recessed, however this embodiment is not limited to plastic substrates. An optional bonding material  825  that can be any type of epoxy or adhesive can be disposed over the interconnect region to provide additional structural integrity for the interconnect. 
     Now referring to  FIG. 11 , another embodiment showing a method of coupling an electrical conductor  310  to an electrically conductive shield  1010  is illustrated. This embodiment is similar to the embodiment illustrated in  FIG. 9 , however in this embodiment an electrically conductive adhesive or other material  1150  is disposed partially over a top surface of conductor and on substrate  820 . In some embodiments electrically conductive adhesive or other material  1150  may provide a more gentle transition for conductive shield  1110  and/or a mechanically buffered interface between conductor  310 , substrate  820  and electrically conductive shield  1110  to make the connection more reliable and less susceptible to cracks forming in the electrically conductive shield. An optional bonding material  825  that can be any type of epoxy or adhesive can be disposed over the interconnect region to provide additional structural integrity for the interconnect. 
     Now referring to  FIG. 12 , a simplified block diagram of various power-related components in a system  1200  that includes a portable electronic device  1210  and a wireless charger  1230  is illustrated. System  1200  can be representative of system  100  or any other inductively charged system. Portable electronic device  1210  can be, for example, portable electronic device  110  discussed above. Wireless charger  1230  can be, for example, wireless charger  120  discussed above. 
     As shown in  FIG. 12 , portable electronic device  1210  includes an inductive power-receiving component  1212  while wireless charger  1230  includes a power-transmitting component  1232 . In system  1200 , power receiving component  1212  can be operatively coupled to power transmitting component  1232  to charge a battery  1213  within the portable electronic device. Within the power receiving component, battery  1213  is operably connected to a receive coil  1214  via power conditioning circuitry  1216 . Receive coil  1214  can be inductively coupled to a transmit coil  1236  of wireless charger  1230  to receive power wirelessly from the charger and pass the received power to battery  1213  within the portable electronic device via power conditioning circuitry  1216 . 
     Power conditioning circuitry  1216  can be configured to convert alternating current received by the receive coil  1214  into direct current power for use by other components of portable electronic device  1210 . Also within device  1210 , a processing unit  1220  may direct the power, via one or more routing circuits and under the execution of an appropriate program residing in a memory  1222 , to perform or coordinate one or more functions of the portable electronic device typically powered by battery  1213 . 
     Within wireless charger  1230 , power transmitting component  1232  includes a power source  1234  operatively coupled to transmit coil  1236  to transmit power to portable electronic device  1210  via electromagnetic induction or magnetic resonance. Transmit coil  1236  can be an electromagnetic coil that produces a time-varying electromagnetic flux to induce a current within an electromagnetic coil within the portable electronic device (e.g., coil  1214 ). The transmit coil may transmit power at a selected frequency or band of frequencies. In one example the transmit frequency is substantially fixed, although this is not required. For example, the transmit frequency may be adjusted to improve power transfer efficiency for particular operational conditions. More particularly, a high transmit frequency may be selected if more power is required by the accessory and a low transmit frequency may be selected if less power is required by the accessory. In other examples, transmit coil  1236  may produce a static electromagnetic field and may physically move, shift, or otherwise change its position to produce a spatially-varying electromagnetic flux to induce a current within the receive coil. 
     When portable electronic device  1210  is operatively attached to wireless charger  1230  (e.g., by aligning charging surface  1215  of device  1210  with charging face  1235  of wireless charger  1230 ), the portable electronic device may use the received current to replenish the charge of its rechargeable battery or to provide power to operating components associated with the electronic device. Thus, when portable electronic device  1210  is operatively attached to wireless charger  1230 , the charger may wirelessly transmit power at a particular frequency via transmit coil  1236  to receive coil  1214  of the portable electronic device. 
     While charger is wirelessly transmitting power electromagnetic noise may be generated that interferes with the operation of a touch sensitive display  1290  of portable electronic device  1210 . In one embodiment an electrically conductive shield  1292  may be placed between receive coil  1214  and charging surface  1215  and coupled to a ground to attenuate the generated electromagnetic noise. In some embodiments electrically conductive shield  1292  can be formed across an entire inner surface of a housing of portable electronic device  1210  or only disposed under receive coil  1214  or a portion of the receive coil. In further embodiments a charger-based electrically conductive shield  1295  disposed within wireless charger  1230  can be used in addition to, or in place of electrically conductive shield  1292 . In further embodiments one or more electrically conductive shields can be disposed at any location between transmit coil  1236  and display  1290  to attenuate electromagnetic noise that interferes with the operation of the touch sensitive display. 
     Transmit coil  1236  can be positioned within the housing of wireless charger such that it aligns with receive coil  1214  in the portable electronic device along a mutual axis when the charger is operatively attached to portable electronic device. If misaligned, the power transfer efficiency between the transmit coil and the receive coil may decrease as misalignment increases. The housing of the portable electronic device and the wireless charger can be designed to facilitate proper alignment between charging surface  1215  and charging face  1235  to ensure high charging efficiency. In some embodiments of the disclosure, transmit coil  1236  is moveable within the housing such that it can be accurately positioned to align with receive coil  1214  of different sized portable electronic devices  1210 . 
     In some embodiments, one or more alignment assistance features can be incorporated into the devices to facilitate alignment of the transmit and receive coils along the mutual axis can be employed. As one example, an alignment magnet  1238  can be included in wireless charger  1230  that magnetically mates with an alignment magnet  1218  of portable electronic device  1210  to facilitate proper alignment of the portable electronic device and wireless charger. Additionally, the charging surface and charging face  1215 ,  1235  of portable electronic device  1210  and wireless charger  1230 , respectively, may cooperate to further facilitate alignment. For example, in one embodiment charging surface  1215  of portable electronic device  1210  has a convex shape while charging face  1235  of wireless charger  1230  has a concave shape. In this manner, the complementary geometries may facilitate alignment of the device charger and wearable device in addition to the alignment magnets. 
     Although electronic device  110  (see  FIG. 1 ) is described and illustrated as one particular electronic device, embodiments of the disclosure are suitable for use with a multiplicity of electronic devices. For example, any device that receives or transmits audio, video or data signals can be used with embodiments of the disclosure. In some instances, embodiments of the disclosure are particularly well suited for use with portable electronic media devices because of their potentially small and portable form factor. As used herein, an electronic media device includes any device with at least one electronic component that can be used to present human-perceivable media. Such devices can include, for example, portable music players (e.g., MP3 devices and Apple&#39;s iPod devices), portable video players (e.g., portable DVD players), cellular telephones (e.g., smart telephones such as Apple&#39;s iPhone devices), video cameras, digital still cameras, projection systems (e.g., holographic projection systems), gaming systems, PDAs, as well as tablet (e.g., Apple&#39;s iPad devices), laptop or other mobile computers. Some of these devices can be configured to provide audio, video or other data or sensory output. 
     For simplicity, various internal components, such as the control circuitry, graphics circuitry, bus, memory, storage device and other components of electronic device  100  (see  FIG. 1 ) are not shown in the figures. 
     In the foregoing specification, embodiments of the disclosure have been described with reference to numerous specific details that can vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the scope of the disclosure, and what is intended by the applicants to be the scope of the disclosure, is the literal and equivalent scope of the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction. The specific details of particular embodiments can be combined in any suitable manner without departing from the spirit and scope of embodiments of the disclosure. 
     Additionally, spatially relative terms, such as “bottom or “top” and the like can be used to describe an element and/or feature&#39;s relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and/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 a “bottom” surface can then be oriented “above” other elements or features. The device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.