PATENT DOCUMENT

Publication Number: US-9246214-B2
Application Number: US-201213415830-A
Country: US
Kind Code: B2

Title: Electronic device antenna structures with ferrite layers

Abstract:
Electronic devices may be provided that have antenna traces. The antenna traces may be configured to form an inductive loop that serves as a near field communications antenna. A layer of ferrite may be provided to reduce interference between the antenna and internal device components. The layer of ferrite and the antenna traces may be deposited on a common substrate such as a layer of polymer or a dielectric electronic device housing. A protective layer of polymer may be used to form a coating on the layer of ferrite. Ferrite may be formed on the same side of a substrate as the antenna traces or may be formed on an opposing side of the substrate.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 antenna structures mounted in the housing, wherein the antenna structures include:
 a layer of polymer having first and second opposing sides and conductive vias extending from the first side to the second side, 
 metal antenna traces formed on the first side of the layer of polymer, 
 a ferrite layer formed on the first side of the layer of polymer that directly covers the antenna traces, and 
 a layer of adhesive located between the layer of polymer and the housing so that the layer of adhesive mounts the layer of polymer directly to the housing; 
 
 a set of electrical contacts at the second side of the layer of polymer that are electrically connected to the conductive vias; and 
 an integrated circuit at the second side of the layer of polymer that is electrically connected to the metal antenna traces through the set of electrical contacts and the conductive vias. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the ferrite layer comprises a polymer ferrite layer. 
     
     
       3. The electronic device defined in  claim 1  wherein the metal antenna traces are configured to form an inductive loop for a near field communications antenna. 
     
     
       4. The electronic device defined in  claim 1  further comprising an additional polymer layer, wherein the additional polymer layer is formed directly over the ferrite layer. 
     
     
       5. The electronic device defined in  claim 1  wherein the ferrite layer comprises a ceramic ferrite, wherein the electronic device further comprises an additional polymer layer, and wherein the additional polymer layer is formed on the ceramic ferrite layer. 
     
     
       6. An electronic device having a length, a width, and a height, wherein the length is greater than the width and the width is greater than the height, comprising:
 a housing for the electronic device; 
 a display module formed within the housing; 
 a display cover layer formed over the display module, wherein the display cover layer extends across the length and the width of the electronic device and the housing comprises a rear housing portion that opposes the display cover layer; and 
 antenna structures mounted in the housing, wherein the antenna structures include:
 a layer of polymer, 
 a ferrite layer formed on the layer of polymer, wherein a first side of the ferrite layer is in direct contact with the polymer, and 
 metal antenna traces formed on and in direct contact with a second side of the layer of ferrite that opposes the first side, wherein the ferrite layer is interposed between the metal antenna traces and the layer of polymer; and 
 
 a layer of adhesive interposed between the ferrite layer and the housing, wherein the metal antenna traces are interposed between the ferrite layer and the layer of adhesive, and wherein the layer of adhesive is configured to mount the antenna structures directly to the rear housing portion such that the adhesive is in direct contact with the rear housing portion; and 
 at least one integrated circuit that is directly connected to the antenna traces using solder, wherein the antenna traces are interposed directly between the solder and the ferrite layer. 
 
     
     
       7. The electronic device defined in  claim 6  wherein the ferrite layer comprises a polymer ferrite layer. 
     
     
       8. The electronic device defined in  claim 6  wherein the metal antenna traces are configured to form an inductive loop for a near field communications antenna. 
     
     
       9. The electronic device defined in  claim 6 , wherein the at least one integrated circuit comprises transceiver circuitry, wherein the at least one integrated circuit is directly connected to the antenna traces at a first location on the antenna traces and at a second location on the antenna traces that is different from the first location using the solder. 
     
     
       10. The electronic device defined in  claim 9 , wherein the solder is interposed directly between the antenna traces and the at least one integrated circuit.

Description:
BACKGROUND 
     This relates generally to electronic devices, and more particularly, to antennas for electronic devices. 
     Electronic devices such as portable computers and cellular telephones are often provided with wireless communications capabilities. For example, electronic devices may include cellular telephone circuitry and wireless local area network circuitry. Electronic devices may also be provided with circuitry for supporting near field communications (NFC). 
     It is often desirable to place a layer of ferrite material between a near field communications antenna and internal device components to reduce interference. This is typically done by laminating a layer of polymer ferrite film to a flexible printed circuit antenna using a layer of adhesive. Ferrite films are also available that use ceramic ferrites sandwiched between a carrier film and a protective film. The ceramic ferrites may be scored in a cross-hatch pattern to promote flexibility. 
     Using adhesive to attach a ferrite film to a flexible printed circuit antenna structure can add undesired thickness to an electronic device. Lamination techniques may also impose undesired process complexity during device fabrication. 
     It would therefore be desirable to be able to provide improved antenna structures with ferrite layers for electronic devices. 
     SUMMARY 
     Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antennas. For example, the wireless communications circuitry may include one or more near field communications antennas. 
     An electronic device may be provided with antenna traces that are configured to form an inductive loop that serves as a near field communications antenna. A layer of ferrite may be provided to reduce interference between the antenna and internal device components. The layer of ferrite may be interposed between the near field communications antenna and the internal device components. A layer of adhesive may be used to mount the near field antenna to an inner surface of an electronic device housing. Adhesive need not be used to laminate the ferrite layer to other antenna structures. Rather, the layer of ferrite and the antenna traces may be deposited on a common substrate such as a layer of polymer or may be formed together on a structure such as a dielectric electronic device housing wall. 
     The layer of ferrite may be formed from a ceramic ferrite or a polymer ferrite material. A protective layer of polymer may be used to form a coating over the layer of ferrite. Ferrite may be formed on the same side of a substrate as the antenna traces or may be formed on an opposing side of the substrate. Antenna traces may be patterned using laser direct structuring and other patterning techniques. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with antenna and ferrite structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross-sectional side view of an illustrative electronic device having antenna and ferrite structures in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of a portion of an electronic device showing how the device may be provided with antenna and ferrite structures in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram of an illustrative near field communications antenna of the type that may be formed from one or more loops of conductive material in accordance with an embodiment of the present invention. 
         FIG. 5  is a diagram showing how antenna and ferrite structures may be provided by depositing polymer ferrite material on a printed circuit with antenna traces in accordance with an embodiment of the present invention. 
         FIG. 6  is a flow chart of illustrative steps involved in forming antenna and ferrite structures of the type shown in  FIG. 5  in accordance with an embodiment of the present invention. 
         FIG. 7  is a diagram showing how antenna and ferrite structures may be formed by depositing polymer ferrite material on a substrate and subsequently forming antenna traces in accordance with an embodiment of the present invention. 
         FIG. 8  is a flow chart of illustrative steps involved in forming antenna and ferrite structures of the type shown in  FIG. 7  in accordance with an embodiment of the present invention. 
         FIG. 9  is a diagram showing how antenna and ferrite structures may be formed using ceramic ferrite material in accordance with an embodiment of the present invention. 
         FIG. 10  is a flow chart of illustrative steps involved in forming antenna and ferrite structures of the type shown in  FIG. 9  in accordance with an embodiment of the present invention. 
         FIG. 11  is a diagram showing how antenna and ferrite structures may be formed by using laser direct structuring techniques to pattern antenna traces on a substrate having a ferrite layer in accordance with an embodiment of the present invention. 
         FIG. 12  is a flow chart of illustrative steps involved in forming antenna and ferrite structures of the type shown in  FIG. 11  by using laser direct structuring techniques to pattern antenna traces on a substrate having a ferrite layer in accordance with an embodiment of the present invention. 
         FIG. 13  is a diagram showing how antenna and ferrite structures may be formed by depositing ferrite material on a substrate with patterned antenna traces formed by laser direct structuring in accordance with an embodiment of the present invention. 
         FIG. 14  is a flow chart of illustrative steps involved in forming antenna and ferrite structures of the type shown in  FIG. 13  by depositing ferrite material on pattern antenna traces formed by laser direct structuring in accordance with an embodiment of the present invention. 
         FIG. 15  is a diagram showing how antenna and ferrite structures may be formed by depositing antenna traces and ferrite material on an electronic device housing in accordance with an embodiment of the present invention. 
         FIG. 16  is a flow chart of illustrative steps involved in forming antenna and ferrite structures on an electronic device housing of the type shown in  FIG. 15  in accordance with an embodiment of the present invention. 
         FIG. 17  is a top view of antenna and ferrite structures showing how a ferrite layer may be selectively formed over part a pattern of antenna traces so that antenna terminals in the antenna traces are accessible for forming electrical contacts in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross-sectional side view of a heated press with a raised region of the type that may be used to form a ceramic ferrite layer on antenna structures in accordance with an embodiment of the present invention. 
         FIG. 19  is a cross-sectional side view of a roller with a raised region for forming patterned polymer ferrite layers in accordance with an embodiment of the present invention. 
         FIG. 20  is a top view of a ceramic ferrite layer with scoring to promote flexibility in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be provided with wireless communications circuitry. The wireless communications circuitry may include one or more antennas. The antennas may include one or more near field communications antennas. As an example, an inductively coupled near field communications antenna may be formed from an inductor structure. The inductor structure may be formed from one or more loops of conductive material. The inductor structure for the near field communications antenna may, for example, be formed from one or more loops of metal traces. 
     A near field antenna of this type may produce electromagnetic fields. To reduce interference between these electromagnetic fields and internal device components, a layer of ferrite material may be interposed between the near field antenna and internal device components. 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a cellular telephone, or a media player. Device  10  may also be a television, a set-top box, a desktop computer, a computer monitor into which a computer has been integrated, or other suitable electronic equipment. 
     Device  10  may have a display such as display  14  that is mounted in a housing such as housing  12 . Display  14  may be a touch screen that incorporates a touch sensor or may be a display that is insensitive to touch. A touch sensor for display  14  may be formed from capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensors. 
     Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover layer may cover the surface of display  14 . The cover layer may be formed from a transparent glass layer, a clear plastic layer, or other transparent member. As shown in  FIG. 1 , openings may be formed in the cover layer to accommodate components such as button  16  and speaker port  18 . 
     Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, housing  12  or parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     In configurations for device  10  in which housing  12  has dielectric portions such as a rear housing surface or other housing wall formed from plastic, glass, or other dielectric material, near field antenna structures may be mounted adjacent to the dielectric portions of the housing. Electromagnetic signals that are transmitted by and received by the near field antenna structures may pass through the dielectric housing portions. 
     A cross-sectional side view of device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may have a display cover layer such as display cover layer  20  that is mounted in housing  12 . Display cover layer  20  may be formed from a layer of transparent glass or plastic (as examples). Display module  22  may be mounted under display cover layer  20 . 
     Housing  12  may have a rear portion such as rear portion  12 ′. Antenna structures  28  may be mounted on the interior surface of rear portion  12 ′ of housing  12  or elsewhere in housing  12 . To ensure that electromagnetic signals associated with antenna structures  28  may pass through housing  12 , housing portion  12 ′ may be formed from a dielectric such as plastic, glass, ceramic, or other dielectric material. In the example of  FIG. 2 , region  12 ′ of housing  12  and antenna structures  28  cover substantially all of the rear surface of device  10 . This is, however, merely illustrative. Antenna structures  28  may be mounted on a smaller portion of the rear surface of housing  12  or in other locations within device  10  if desired. 
     Device  10  may include internal components such as components  26 . Components  26  may be mounted on one or more substrates such as substrate  24 . Components  26  may include wireless circuitry such as near field communications transceiver circuitry operating at 13.56 MHz or other suitable wireless circuitry, processor integrated circuits, switches, connectors, application-specific integrated circuits, and other circuitry. 
     Substrate  24  may be formed from plastic or may be implemented using one or more printed circuits. For example, substrate  24  may be a flexible printed circuit (“flex circuit”) formed from a flexible sheet of polyimide or other polymer layer or may be a rigid printed circuit board (e.g., a printed circuit board formed from fiberglass-filled epoxy). Substrate  24  may include conductive interconnect paths such as one or more layers of patterned metal traces for routing signals between components  26  and antenna structures  28 . If desired, transmission line structures such as coaxial cables, flexible printed circuit cables, traces on rigid printed circuit boards, and other transmission line structures may be used in interconnecting wireless circuitry in components  26  with antenna structures  28 . As an example, a transmission line structure may be used to couple a near field communications (NFC) transceiver circuit in components  26  to antenna structures  28 . 
     A cross-sectional side view of a portion of device  10  showing how antenna structures  28  may be mounted in device  10  between housing  12  and internal components  26  is shown in  FIG. 3 . During operation, radio-frequency electromagnetic signals such as wireless signals associated with near field communications or other wireless communications may pass through housing  12  (e.g., dielectric portion  12 ′ of housing  12 ). Structures  28  may include a layer of ferrite material such as ferrite layer  28 F and a layer of antenna structures such as antenna structures  28 A. Antenna structures  28 A may be used to transmit and receive wireless signals such as near field communications signals. Ferrite layer  28 F may help shield internal components  26  from exposure to these signals during operation of device  10 . 
     Antenna structures  28 A may include metal antenna traces on a substrate. Ferrite layer  28 F may be formed on the substrate without using any adhesive layers (i.e., without using adhesive interposed between ferrite layer  28 F and the substrate for structures  28 A), thereby helping to minimize the thickness of structures  28 . 
     Ferrite layer  28 F may be formed from ferrite material in a polymer binder (sometimes referred to as polymer ferrite), a ceramic ferrite material (sometimes referred to as a ceramic ferrite), or other suitable ferrite materials. The polymer material that is used as a binder in a polymer ferrite may provide sufficient structural support to allow the polymer ferrite to be formed in a layer without requiring a film backing. Ceramic ferrite structures may be formed on a substrate such as a polymer film substrate. Protective polymer films may be provided on ferrite layer  28 F to help prevent ferrite layer  28 F from becoming damaged during assembly. 
     Antenna structures  28 A may be formed from conductive materials such as metals. As an example, antenna structures  28 A may be formed from metal traces that have been patterned into the shape of an inductor for supporting inductively coupled near field communications. Patterned metal traces for antenna structures.  28 A may be formed on a dielectric support structure such as part of housing  12 , a polymer film, a plastic carrier, a rigid printed circuit board, or other suitable substrate. As shown in  FIG. 3 , antenna structures  28  may be mounted to housing  12  using adhesive layer  30 . 
     A top view of antenna structures  28 A showing an illustrative layout that may be used for conductive antenna traces  32  is shown in  FIG. 4 . As shown in  FIG. 4 , traces  32  may form one or more loops of conductive lines for forming an inductive near field communications antenna. In the example of  FIG. 4 , the antenna has two loops of conductive lines. This is merely illustrative. An antenna formed from traces  32  may have a single loop, a double loop, or may have three or more loops of conductive lines (e.g., 1-10 loops, more than 5 loops, 5-10 loops, fewer than 10 loops, etc.). 
     Traces  32  may have terminals such as terminals  36 . Terminals  36  may sometimes be referred to as antenna feed terminals and may be coupled to near field communications transceiver circuitry or other wireless transceiver circuitry in components  26  ( FIG. 2 ) using a transmission line. Antenna traces  32  may be formed on a dielectric layer such as illustrative substrate layer  34 . Substrate layer  34  may be formed from a portion of housing  12 , a flexible polymer layer, a plastic carrier, or other dielectric structures. Polymer layers for forming substrates and/or optional protective coating layers in antenna structures  28  may be formed from layers of polyimide, polyethylene terephthalate (PET), or other polymers. 
       FIG. 5  is a diagram showing how antenna structures such as antenna structures  28  of  FIG. 3  may be formed by depositing ferrite material onto a substrate containing antenna traces for antenna structures  28 A. 
     Initially, processing equipment  40  may be used to form antenna traces  32  on substrate  38 . Substrate  38  may be a flexible sheet of polymer. Processing equipment  40  may include equipment for depositing and patterning metal traces  32 . Processing equipment  40  may, for example, include equipment for deposing and patterning metal traces  32  using screen printing, ink-jet printing, spraying, physical vapor deposition, chemical vapor deposition, photolithography, electroplating, pad printing, or other suitable metal deposition and patterning equipment. If desired, equipment  40  may include etching equipment or other equipment for forming vias such as vias  42 . Vias  42  may be used in forming backside contacts to traces  32  (e.g., to form backside contacts for antenna feed terminals in traces  32  such as antenna feed terminals  36  of  FIG. 4 ). 
     Following the formation of patterned antenna traces  32  on substrate  38 , ferrite deposition equipment  56  may be used to deposit a ferrite layer such as ferrite layer  52 . Ferrite deposition equipment  56  may include roller-based deposition equipment or other suitable deposition equipment. 
     Ferrite layer  52  of  FIG. 5  may be, for example, a polymer ferrite layer. Ferrite layer  52  may be deposited on top of traces  32  and substrate  38  using a continuous roller deposition process or other suitable deposition process to form antenna structures  28 . By forming ferrite layer  52  on traces  32  and substrate  38 , the need for using adhesive-based lamination processes to attach a separate sheet of ferrite material to traces  32  and substrate  38  may be avoided. 
     As shown in  FIG. 5 , equipment  56  may include roller  46  and ferrite material dispensing tool  58 . Roller  46  may be rotated in direction  48  about rotation axis  44  as substrate  38  moves in direction  54 . As roller  46  is rotated, liquid polymer ferrite material  50  may be dispensed by dispensing tool  58 . Roller  46  may thin the dispensed polymer ferrite material to form polymer ferrite layer  52  on antenna traces  32  and on polymer layer  38 . If desired, an optional protective layer such as optional protective polymer layer  60  may be deposited on top of polymer ferrite layer  52  (e.g., by using roller  46  or other deposition equipment to attach a polymer sheet or to otherwise form a polymer layer on layer  52 ). If vias  42  were not formed before formation of layer  52 , equipment such as equipment  40  (e.g., via etching equipment) may be used to form vias  42  following formation of layer  52  and optional layer  60 . 
     Component mounting equipment  62  may be used to attach one or more components such as components  64  to antenna structures  28 . Components  64  may be mounted to backside contacts on substrate  38  formed using vias  42 . Components  64  may include a connector (e.g., a connector for coupling a transmission line to antenna traces  32 ), a part of a flexible printed circuit cable (e.g., part of a flexible printed circuit cable containing a transmission line for coupling to traces  32 ), one or more integrated circuits (e.g., transceiver circuitry), discrete circuit components, or other components. Components  64  may be mounted to backside contacts formed using vias  42  by solder  66 . Component mounting equipment  62  may include equipment for forming solder connections  66  (e.g., a reflow oven, pick and place equipment for mounting components, hot-bar equipment for soldering, etc.). 
     Illustrative steps involved in forming antenna structures  28  using an approach of the type shown in  FIG. 5  are shown in  FIG. 6 . 
     At step  68 , processing equipment  40  may be used to form patterned antenna traces  32  on a polymer film or other suitable substrate (substrate  38 ). 
     At step  70 , deposition equipment  56  may be used to deposit polymer ferrite layer  52  and optional protective polymer layer  60  on substrate  38  over traces  32 . In forming ferrite layer  52  on traces  32  and substrate  38 , no adhesive need be used, because the ferrite material that forms ferrite layer  52  can be deposited directly on traces  32  and substrate  38 . Vias  42  may be formed before and/or after formation of layer  52 , if desired. 
     At step  72 , components  64  may be mounted to antenna structures  28  using equipment  62  (e.g., using solder  66 ). 
     At step  74 , antenna structures  28  may be mounted in housing  12  of device  10  (e.g., using adhesive  30  of  FIG. 3 ). 
       FIG. 7  is a diagram showing how antenna structures such as antenna structures  28  of  FIG. 3  may be formed by depositing antenna traces  32  on ferrite material such as polymer ferrite material following formation of a ferrite layer on a substrate. 
     Initially, ferrite deposition equipment  56  such as dispenser  58  and roller  46  may deposit ferrite layer  52  on substrate  38 . Substrate  38  may be a flexible sheet of polymer. Ferrite layer  52  may be a polymer ferrite layer. Layer  52  may be formed directly on substrate  38  using equipment  56  of  FIG. 6  or other suitable deposition equipment. 
     After forming layer  52 , processing equipment  40  may deposit patterned antenna traces  32  on layer  52  to form antenna structures  28 . 
     Following formation of antenna structures  28 , component mounting equipment  62  may be used to attach one or more components  64  to antenna structures  32 . Component mounting equipment  62  may, for example, use solder  66  to attach one or more components  64  to antenna feed terminals formed from traces  32  such as terminals  36  of  FIG. 4 . 
     Illustrative steps involved in forming antenna structures  28  using an approach of the type shown in  FIG. 7  are shown in  FIG. 8 . 
     At step  76 , ferrite deposition equipment such as equipment  56  of  FIG. 7  may be used to deposit ferrite layer  52  on substrate  38 . Ferrite layer  52  may be, for example, a polymer ferrite layer. Substrate  38  may be a layer of polyimide, a PET layer, or other polymer film. 
     At step  78 , following formation of ferrite layer  52 , equipment  40  may be used to form patterned antenna traces  32  on ferrite layer  52  (e.g., traces  32  may be deposited directly on layer  52 ) to form antenna structures  28 . 
     After forming antenna structures  28 , component mounting equipment  62  may be used to mount one or more components  64  to antenna structures  28  (step  80 ). 
     At step  82 , antenna structures  28  may be mounted in housing  12  of device  10  (e.g., using adhesive  30  of  FIG. 3 ). 
       FIG. 9  is a diagram showing how antenna structures such as antenna structures  28  of  FIG. 3  may be formed by depositing material such as ceramic ferrite material on a substrate. 
     Initially, processing equipment  40  may be used to form patterned antenna traces  32  on substrate  38 . Substrate  38  may be a flexible sheet of polymer. Processing equipment  40  may include equipment for depositing and patterning metal traces  32  directly on substrate  38 . If desired, equipment  40  may include etching equipment or other equipment for forming vias such as vias  42 . Vias  42  may be used in forming backside contacts to traces  32  (e.g., to form backside contacts for antenna feed terminals in traces  32  such as antenna feed terminals  36  of  FIG. 4 ). 
     Following the formation of patterned antenna traces  32  on substrate  38 , ceramic ferrite deposition equipment  84  may be used to deposit ceramic ferrite layer  52  on substrate  38  covering patterned antenna traces  32 . Equipment  84  may be a heated press that is heated to a temperature of about 50-200° C. or other suitable temperatures such as temperatures below 100° C. or above 100° C. For example, equipment  84  may have an upper press portion such as portion  84 A that presses downwards in direction  86  and a lower press portion such as portion  84 B that presses upwards in direction  88 . 
     To help protect ceramic ferrite layer  52  during subsequent handling, a protective layer such as polymer film  60  may be pressed onto the top of ceramic ferrite layer  52  during operation of press  84 . Vias  42  may be formed in layer  38  following formation of ceramic ferrite layer  52  (e.g., if vias  42  were not formed previously). 
     Following formation of antenna structures  28  by depositing ceramic ferrite layer  52  using equipment such as equipment  84  of  FIG. 9  or other suitable ceramic ferrite deposition equipment, component mounting equipment  62  may be used to mount one or more components such as component  64  to antenna structures  28 . Equipment  64  may, as an example, use solder  66  to solder components  64  to backside contacts formed from vias  42 , thereby coupling components  64  to antenna traces  32  (e.g., antenna terminals  36 ). 
     Illustrative steps involved in forming antenna structures  28  using an approach of the type shown in  FIG. 9  are shown in  FIG. 10 . 
     At step  90 , processing equipment  40  may be used to form patterned antenna traces  32  on a polymer film or other suitable substrate (e.g., traces  32  may be deposited directly on substrate  38 ). 
     At step  92 , deposition equipment  84  may be used to deposit ceramic ferrite layer  52  and optional protective polymer layer  60  on substrate  38  over traces  32 , thereby forming antenna structures  28 . No adhesive layer need be used to form layer  52  on substrate  38 , because layer  52  may be deposited directly on substrate  38  and traces  32 . Vias  42  may be formed before and/or after formation of layer  52 . 
     At step  94 , components  64  may be mounted to antenna structures  28  using equipment  62  (e.g., using solder  66 ). 
     At step  96 , antenna structures  28  may be mounted in housing  12  of device  10  (e.g., using adhesive  30  of  FIG. 3 ). 
       FIG. 11  is a diagram showing how antenna structures such as antenna structures  28  of  FIG. 3  may be formed by depositing ferrite material on a substrate that is subsequently processed using laser direct structuring equipment to form antenna traces  32 . 
     Initially, ferrite deposition equipment  100  may be used to deposit ferrite layer  102  on substrate  98 . Ferrite layer  102  may be a polymer ferrite layer or a ceramic ferrite layer and may have an optional protective polymer coating layer. Substrate  98  may be plastic with a metal complex additive suitable for processing using laser direct structuring (LDS) equipment such as equipment  104 . 
     During operation of equipment  104 , light (e.g., laser light) may be directed onto selective areas on the surface of substrate  38  to activate the surface of substrate  38  in a desired pattern. During subsequent metallization using equipment  104 , metal traces such as metal antenna traces  32  of  FIG. 11  may be grown over the activated regions of substrate  98  to form antenna structures  28 . As shown in  FIG. 11 , substrate  98  may have opposing upper and lower surfaces. Ferrite layer  102  may be formed on the lower surface and antenna traces  32  may be formed on the upper surface. 
       FIG. 12  is a flow chart of illustrative steps involved in forming antenna structures  28  using an approach of the type shown in  FIG. 11 . 
     At step  106 , ferrite deposition equipment such as equipment  100  of  FIG. 11  may be used to deposit ferrite layer  102  on substrate  98 . Ferrite layer  102  may be, for example, a polymer ferrite layer or a ceramic ferrite layer that is deposited directly on substrate  98 . An optional coating such as a layer of polymer may be formed on top of layer  102  to help protect the ferrite material in layer  102  from damage during assembly operations. Substrate  98  may be a plastic carrier or sheet of polymer suitable for patterning using laser direct structuring equipment  104 . 
     At step  108 , following formation of ferrite layer  52 , equipment  104  may be used to form patterned antenna traces  32  on substrate  98  (e.g., by depositing traces  32  directly on substrate  98 ). 
     After forming antenna structures  28  in this way, component mounting equipment  62  may be used to mount one or more components  64  to antenna structures  28  (step  110 ). 
     At step  102 , antenna structures  28  may be mounted in housing  12  of device  10  (e.g., using adhesive  30  of  FIG. 3 ). 
     With the approach of  FIGS. 11 and 12 , ferrite layer  102  was deposited on substrate  98  before substrate  98  was processed using laser direct structuring equipment  104 . If desired, substrate  98  may be processed using laser direct structuring equipment  104  before ferrite layer  102  is deposited. This type of arrangement is shown in  FIG. 13 . 
     As shown in  FIG. 13 , laser direct structuring equipment  104  may be used to process substrate  98  to form antenna traces  32 . Antenna traces  32  may be formed directly on the upper surface of substrate  98  or may, as indicated by traces  32 ′ of  FIG. 13 , be formed directly on the lower surface of substrate  98 . 
     Following formation of antenna traces  32  or  32 ′, ferrite deposition equipment  100  may be used to deposit ferrite layer  102  on substrate  98  (e.g., by directly forming layer  102  on the surface of substrate  98 ). In configurations in which antenna traces  32  have been formed on the upper surface of substrate  98 , traces  32  will remain uncovered following formation of ferrite layer  102  on the opposing lower surface of substrate  98 . In configurations in which antenna traces  32 ′ have been formed on the lower surface of substrate  98 , ferrite layer  102  will cover antenna traces  32 ′ because ferrite layer  102  and antenna traces  32 ′ will both reside on the lower surface on substrate  98 . An advantage to forming traces  32  on the upper surface of substrate  98  is that this type of configuration may help provide dielectric separation between traces  32  and layer  102 , which may help to improve antenna performance. An advantage to forming traces  32 ′ on the lower surface of substrate  98  is that this may help to enclose traces  32 ′ in protective layers, thereby reducing the opportunity for damage due to moisture exposure (e.g., in situations in which adhesive layer  30  of  FIG. 3  is thin or is not used). 
       FIG. 14  is a flow chart of illustrative steps involved in forming antenna structures  28  using an approach of the type shown in  FIG. 13 . 
     At step  114 , laser direct structuring equipment such as equipment  104  of  FIG. 13  may be used to form antenna traces such as traces  32  or  32 ′ on substrate  98 . 
     At step  116 , ferrite deposition equipment such as equipment  100  of  FIG. 13  may be used to deposit ferrite layer  102  on substrate  98 . 
     After forming antenna structures  28  in this way, component mounting equipment  62  may be used to mount one or more components  64  to antenna structures  28  (step  118 ). 
     At step  120 , antenna structures  28  may be mounted in housing  12  of device  10  (e.g., using adhesive  30  of  FIG. 3 ). 
     If desired, antenna structures  28  may be formed directly on a housing structure in device  10 . As shown in  FIG. 15 , for example, equipment  122  may be used to form patterned antenna traces  32  directly on the inner surface of housing  12  (or on dielectric structure that is mounted in housing  12 ). Equipment  122  may be laser direct structuring equipment such as equipment  104  of  FIGS. 11 and 13 , processing equipment  40  such as processing equipment  40  of  FIGS. 5 ,  7 , and  9 , or other suitable equipment for forming patterned metal antenna traces  32  on housing  12 . 
     Following formation of traces  32 , an optional layer of dielectric material may be formed on traces  32  such as layer  124 . Layer  124  may be deposited by deposition equipment  122  (e.g., using spraying, screen printing, ink-jet printing, etc.). If desired, layers such as layer  124  may also be deposited on top of traces  32  in the previously described arrangements for antenna structures  28 . 
     After traces  32  and, if desired, optional layer  124  have been formed, ferrite deposition equipment  100  may be used to deposit ferrite layer  102  over traces  32  and layer  124  to form antenna structures  28 . Ferrite layer  102  may be a polymer ferrite layer, a ceramic ferrite layer, or other suitable layer including ferrite material. Layer  102  may be formed directly on housing  12  and traces  32  or, if layer  124  is present, layer  102  may be formed directly on layer  124 . 
     When forming layers such as dielectric layer  124  and ferrite layer  102 , it may be desirable to leave portions of antenna traces  32  uncovered. This allows component mounting equipment  62  to attach one or more components  64  to antenna traces  32  using solder  66 . If desired, vias or other openings may be formed in layers such as layers  102  and  124  (e.g., using mechanical machining equipment, by removing a temporary protective film, using etching, or using other material removal techniques). 
       FIG. 16  is a flow chart of illustrative steps involved in forming antenna structures such as antenna structures  28  of  FIG. 15 . 
     At step  126 , deposition equipment  122  may be used to deposit patterned metal traces  32  and optional dielectric layer  124  on a substrate such as housing  12 . 
     At step  128 , ferrite deposition equipment such as equipment  100  of  FIG. 15  may be used to deposit ferrite layer  102  on traces  32  and housing  12  (or on traces  32  and layer  124  if layer  124  is present). Portions of traces  32  may be left uncovered by layers  124  and  102  or portions of layers  124  and  102  may be subsequently removed to form contacts for antenna terminals  36  in traces  34 . 
     After forming antenna structures  28  in this way, component mounting equipment  62  may be used to mount one or more components  64  to antenna structures  28  (step  130 ). 
       FIG. 17  is a top view of illustrative antenna structures  28 A showing how ferrite material may cover over only part of antenna traces  32 . Region  134  may, for example, be covered with one or more layers of material such as a layer of ferrite material and, if desired, a layer of polymer or other dielectric that is interposed between the ferrite layer and traces  32 . Region  132  (in the example of  FIG. 17 ) may be left uncovered by ferrite material during the process of covering region  134  with ferrite material. If desired, ferrite material may initially be deposited in region  132 . This ferrite material may then be selectively removed from region  132 . By ensuring that no ferrite material or dielectric material remains in region  132 , solder  66  may be used attaching component  64  to traces  32  (e.g., to terminals  36  of  FIG. 4 ). 
     When using a ferrite deposition tool such as ferrite deposition equipment  56  of  FIGS. 5 and 7 , ferrite deposition equipment (heat press)  84  of  FIG. 9 , or ferrite deposition equipment  100  of  FIGS. 11 and 13  to deposit ferrite, portions of the deposition tool may be locally raised to prevent ferrite from being deposited in regions such as region  132  of  FIG. 17 . As shown in  FIG. 18 , for example, upper press portion  84 A may have a raised area such as area  84 A′ that helps prevents ferrite  140  from being deposited on the upper surfaces of traces  32  on substrate  142  in region  132 . As shown in  FIG. 19 , ferrite deposition roller  46  may likewise have one or more raised features such as raised portion  46 ′ for creating localized regions on antenna structures  28  in which portions of antenna traces  32  are uncovered by ferrite. 
     As shown in  FIG. 20 , ferrite material  144  may, if desired, be provided with grooves (scoring) such as cross-hatched patterned grooves  146 . Grooves  146  may provide ferrite material that might otherwise be stiff and prone to fracturing such as rigid ceramic ferrite with an enhanced ability to flex. Enhanced flexibility may be used, for example, to help mount ferrite material  144  in a curved housing and/or may help avoid damage to material  144  during automated and/or manual assembly operations. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20120308
Publication Date: 20160126
Grant Date: 20160126
Priority Date: 20120308
Inventors: POPE BENJAMIN J.
MYERS SCOTT A.
PASCOLINI MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q7/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q7/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 49113618