PATENT DOCUMENT

Publication Number: US-9186828-B2
Application Number: US-201213490356-A
Country: US
Kind Code: B2

Title: Methods for forming elongated antennas with plastic support structures for electronic devices

Abstract:
Electronic devices may be provided with antenna structures. The antenna structures may include an antenna support structure covered with patterned antenna traces. An antenna support structure may be mounted in an electronic device so that a surface of the antenna support structure that is covered with patterned antenna traces lies flush with a planar surface of the electronic device housing. A display cover layer or other planar structure may be attached to the surface of the antenna support structure and the planar surface of the housing adhesive. Injection molding and extrusion techniques may be used in forming a support structure with elongated parallel cavities. An injection molding tool may have a mold core supported by a support structure at one end, supporting engagement features at the ends of mating mold core structures, or support pins. Molded interconnect devices may be soldered to laser direct structuring components to form antennas.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 an antenna that is attached to the housing, wherein the antenna has an antenna surface; 
 a dielectric member; and 
 adhesive that attaches the dielectric member to the antenna surface, wherein the antenna comprises a hollow plastic support structure having patterned metal antenna traces on the antenna surface. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the housing has at least one housing surface that is flush with the antenna surface and wherein the adhesive attaches the dielectric member to the housing surface and the antenna surface. 
     
     
       3. The electronic device defined in  claim 2  wherein the dielectric member comprises a transparent dielectric member. 
     
     
       4. The electronic device defined in  claim 2  wherein the dielectric member comprises a display cover layer, wherein the electronic device further comprises display structures that include an array of display pixels, and wherein the display cover layer covers the display structures. 
     
     
       5. The electronic device defined in  claim 4  wherein the antenna comprises:
 a dielectric support structure; and 
 patterned metal antenna traces on the antenna surface. 
 
     
     
       6. The electronic device defined in  claim 5  wherein the hollow plastic support structure has a portion that forms the antenna surface and wherein the electronic device comprises screws that mount the hollow plastic support structure to the housing. 
     
     
       7. The electronic device defined in  claim 1  wherein the housing comprises a metal housing and wherein the dielectric member comprises a display cover layer. 
     
     
       8. The electronic device defined in  claim 1  wherein the hollow plastic support structure comprises an extruded hollow plastic support structure. 
     
     
       9. An electronic device, comprising:
 a housing; 
 an antenna that is attached to the housing, wherein the antenna has an antenna surface; 
 a dielectric member; 
 adhesive that attaches the dielectric member to the antenna surface, wherein the housing comprises a metal housing; and 
 conductive foam that electrically shorts the patterned metal antenna traces to the metal housing. 
 
     
     
       10. The electronic device defined in  claim 9  wherein the antenna comprises a loop antenna resonating element. 
     
     
       11. An antenna, comprising:
 a first portion comprising a first plastic support with antenna traces, wherein the first plastic support comprises first and second shots of plastic with different metal affinities; and 
 a second portion comprising a second plastic support with antenna traces. 
 
     
     
       12. The antenna defined in  claim 11  wherein the second portion comprises a laser direct structuring plastic support with patterned metal traces. 
     
     
       13. The antenna defined in  claim 12  further comprising solder with which the patterned metal traces on the laser direct structuring plastic support are soldered to the antenna traces on the first portion. 
     
     
       14. The antenna defined in  claim 13  wherein the antenna traces on the first and second portions are configured to form a loop antenna resonating element. 
     
     
       15. The antenna defined in  claim 13 , wherein a bent lip structure on the patterned metal traces on the laser direct structuring plastic support are soldered to a bent lip structure on the antenna traces on the first portion. 
     
     
       16. The antenna defined in  claim 11 , wherein the first plastic support comprises a first extruded hollow plastic support structure. 
     
     
       17. The antenna defined in  claim 16 , wherein the second plastic support comprises a second extruded hollow support structure. 
     
     
       18. The antenna defined in  claim 11 , wherein the second shot of plastic in the first plastic support contacts the second plastic support. 
     
     
       19. A method of forming an antenna, comprising:
 injection molding a first antenna support structure from first and second shots of plastic having different metal affinities; 
 coating the first antenna support structure with metal that covers the first shot of plastic while leaving the second shot of plastic uncovered by metal; 
 using laser processing to form a second antenna support structure with patterned antenna traces; and 
 attaching the first antenna support structure to the second antenna support structure to form the antenna. 
 
     
     
       20. The method defined in  claim 19  wherein attaching the first antenna support structure to the second antenna support structure comprises soldering the first antenna support structure to the second antenna support structure. 
     
     
       21. The method defined in  claim 20  wherein using laser processing comprises forming the second antenna support structure by performing laser direct structuring operations with laser direct structuring equipment. 
     
     
       22. An electronic device, comprising:
 a housing; 
 an antenna that is attached to the housing, wherein the antenna has an antenna surface; 
 a dielectric member; and 
 adhesive that attaches the dielectric member to the antenna surface, wherein the housing has at least one housing surface that is flush with the antenna surface and the adhesive attaches the dielectric member to the housing surface and the antenna surface, the antenna surface comprises a curved antenna surface, and the at least one housing surface comprises a curved housing surface that lies flush with the curved antenna surface. 
 
     
     
       23. The electronic device defined in  claim 22 , wherein the dielectric member comprises a planar dielectric member. 
     
     
       24. The electronic device defined in  claim 23 , wherein the dielectric member comprises a transparent display cover layer for a display in the electronic device. 
     
     
       25. The electronic device defined in  claim 24 , wherein the antenna comprises:
 a dielectric support structure having a first planar surface that is substantially parallel to the display cover layer and a second planar surface that extends perpendicular to the first planar surface; and 
 patterned metal antenna traces on the antenna surface, wherein the display comprises a display module interposed between the display cover layer and the first planar surface of the dielectric support structure.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to forming antennas for electronic devices. 
     Electronic devices such as computers are often provided with antennas. For example, a computer monitor with an integrated computer may be provided with antennas that are located along an edge of the monitor. 
     Challenges can arise in mounting antennas within an electronic device. For example, the relative position between an antenna and surrounding device structures and the size and shape of antenna structures can have an impact on antenna tuning and bandwidth. If care is not taken, an antenna may become detuned or may exhibit an undesirably small efficiency bandwidth at desired operating frequencies. Unsatisfactory antenna mounting configurations have the potential to compromise the structural integrity of an electronic device. Methods for forming antenna structures should be cost effective and capable of producing high-performing antennas, so as to avoid undesired expense and shortcomings in wireless performance. 
     It would therefore be desirable to be able to provide improved antennas for use in electronic devices. 
     SUMMARY 
     Electronic devices may be provided with antenna structures. The antenna structures may include an antenna support structure covered with patterned antenna traces. An antenna support structure may be formed from a dielectric such as plastic. Antenna traces on a support structure may be formed from a conductive material such as metal. The antenna traces may be used to form a loop antenna structure or other types of antenna. 
     An antenna may be mounted in an electronic device so that a surface of an antenna support structure that is covered with patterned antenna traces lies flush with a planar surface of the electronic device housing. A display cover layer or other planar structure may be attached to the surface of the antenna support structure and the planar surface of the housing adhesive. 
     Injection molding techniques may be used in forming an antenna support structure. The antenna support structure may be formed from a hollow plastic member and may have elongated parallel cavities. 
     An injection molding tool for forming a plastic antenna support structure may have an outer mold and a mold core. The mold core may have parallel elongated members for forming the elongated parallel cavities. 
     During injection molding, the mold core may be supported. The mold core may, for example, be supported by a support structure that engages one of the ends of an elongated mold core structure. If desired, the mold core may be formed by opposing elongated mold core structures. The opposing mold core structures may engage one another using matching engagement features located at the ends of the structures. Each of these mold core structures may include multiple parallel elongated mold core members for forming hollow plastic antenna support structures with parallel elongated cavities. Mold core structures may also be supported using support pins. 
     Antennas may be formed from multiple parts. Antenna parts may, for example, be formed using injection molding, laser patterning, and other fabrication techniques. As an example, a first portion of an antenna may be formed from a molded interconnect device. The molded interconnect device may be formed from first and second shots of plastic having different metal affinities. Metal antenna traces may be formed on the first shot of plastic while leaving the second shot of plastic uncovered by metal. A second portion of the same antenna may be formed using laser direct structuring. The first and second portions of the antenna may be connected to each other to form an antenna. For example, solder may be used to connect the first and second portions. 
     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 structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative distributed loop antenna having a main body portion and an extending tail portion in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of an edge portion of an electronic device of the type shown in  FIG. 1  in which an antenna such as antenna of the type shown in  FIG. 2  has been mounted in accordance with an embodiment of the present invention. 
         FIG. 4  is a perspective view of an illustrative antenna of the type that may be mounted in an edge portion of an electronic device such as the electronic device of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional view of an antenna such as the antenna of  FIG. 4  mounted within an electronic device in accordance with an embodiment of the present invention. 
         FIG. 6  is an exploded perspective view of a plastic injection molding tool having an outer mold structure and a mold core with multiple parallel mold core members in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of a portion of an injection molding tool showing how a stabilizing member such as a pin may pass through an opening in an injection molding wall to stabilize a mold core structure in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of an illustrative injection molding tool having integral support pin structures for supporting a mold core in accordance with an embodiment of the present invention. 
         FIG. 9  is a diagram showing how a laser direct structuring tool may be used to pattern an antenna substrate in accordance with an embodiment of the present invention. 
         FIG. 10  is a diagram showing how a tapered mold core member and a support structure may be used in an injection molding machine in accordance with an embodiment of the present invention. 
         FIG. 11  is a diagram showing how a mold core in an injection molding machine may be supported by a support having a protrusion that mates with a corresponding recess in the mold core in accordance with an embodiment of the present invention. 
         FIG. 12  is a diagram showing how a mold core in an injection molding machine may be supported using interlocking features on the ends of two mating mold core structures in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional view of an injection molding tool showing how the injection molding tool may form a cavity of a desired shape in accordance with an embodiment of the present invention. 
         FIG. 14  is a cross-sectional side view of the injection molding tool of  FIG. 13  following injection molding of a first shot of plastic and removal of a first mold core in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional side view of the injection molding tool of  FIG. 14  having a second mold core that is being used to injection mold a second shot of plastic over the first shot of plastic in accordance with an embodiment of the present invention. 
         FIG. 16  is a diagram showing how an injection molded part of the type formed using equipment of the type shown in  FIGS. 13 ,  14 , and  15  may be coated with metal to form a patterned metal layer for an antenna in accordance with an embodiment of the present invention. 
         FIG. 17  is a diagram showing how laser direct structuring techniques may be used to form part of an antenna that is assembled with other patterned antenna parts to form an electronic device antenna in accordance with an embodiment of the present invention. 
         FIG. 18  is a perspective view of an extrusion tool of the type that may be used to form an antenna support structure for an antenna in accordance with an embodiment of the present invention. 
         FIG. 19  is a perspective view of an illustrative antenna support having a die-cut feature in accordance with an embodiment of the present invention. 
         FIG. 20  is a perspective view of an illustrative antenna support structure of the type that may be formed using machining tools or other equipment in accordance with an embodiment of the present invention. 
         FIG. 21  is a flow chart of illustrative steps involved in forming electronic device antenna structures in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with antennas and other wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. One or more antennas may be provided in an electronic device. For example, antennas may be used to form an antenna array to support communications with a communications protocol such as the IEEE 802.11(n) protocol that uses multiple antennas. 
     An illustrative electronic device of the type that may be provided with one or more antennas is shown in  FIG. 1 . Electronic device  10  may be a computer such as a computer that is integrated into a display such as a computer monitor. Electronic device  10  may also be a laptop computer, a tablet computer, a somewhat smaller portable device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a cellular telephone, a media player, or other electronic equipment. Illustrative configurations in which electronic device  10  is a computer formed from a computer monitor are sometimes described herein as an example. In general, electronic device  10  may be any suitable electronic equipment. 
     Antennas may be formed in device  10  in any suitable location such as location  26  or other locations along the edge of the housing for device  10 . The antennas in device  10  may include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, cavity antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. The antennas may cover cellular network communications bands, wireless local area network communications bands (e.g., the 2.4 and 5 GHz bands associated with protocols such as the Bluetooth® and IEEE 802.11 protocols), and other communications bands. The antennas may support single band and/or multiband operation. For example, the antennas may be dual band antennas that cover the 2.4 and 5 GHz bands. The antennas may also cover more than two bands (e.g., by covering three or more bands or by covering four or more bands). 
     Conductive structures for the antennas may, if desired, be formed from conductive electronic device structures such as conductive housing structures, from conductive structures such as metal traces on plastic carriers, from metal traces in flexible printed circuits and rigid printed circuits, from metal foil supported by dielectric carrier structures, from wires, from other conductive materials, and from structures including two or more or three or more of these types of conductive structures. 
     Device  10  may include a display such as display  18 . Display  18  may be mounted in a housing such as electronic device housing  12 . Housing  12  may be supported using a stand such as stand  14  or other support structure. 
     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. Internal housing structures such as metal plates, frame structures, and other housing members may be included in device  10 , if desired. In some situations, 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. 
     Display  18  may be a touch screen that incorporates capacitive touch electrodes or other touch sensor components or may be a display that is not touch sensitive. Display  18  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrophoretic ink elements, electrowetting display elements, liquid crystal display (LCD) components, or other suitable image pixel structures. 
     A display cover layer such as a layer of cover glass, a plastic cover layer, or other transparent planar dielectric member may cover the surface of display  18 . Rectangular active region  22  of display  18  may lie within rectangular boundary  24 . Active region  22  may contain an array of image pixels that display images for a user. Active region  22  may be surrounded by an inactive peripheral region such as rectangular ring-shaped inactive region  20 . The inactive portions of display  18  such as inactive region  20  are devoid of active image pixels. Display driver circuits, antennas (e.g., antennas in regions such as region  26 ), and other components that do not generate images may be located under inactive region  20 . 
     The cover layer for display  18  may cover both active region  22  and inactive region  20 . The inner surface of the cover layer in inactive region  20  may be coated with a layer of an opaque masking material such as opaque plastic (e.g., a dark polyester film) or black ink. The opaque masking layer may help hide internal components in device  10  such as antennas, driver circuits, housing structures, mounting structures, and other structures from view. If desired, display  18  may be implemented using a borderless or nearly borderless configuration in which inactive region  20  is omitted or reduced in size. 
     In a configuration for display  18  that includes an inactive region, the inactive region may, if desired, overlap antennas in device  10 . For example, antennas may be mounted in region  26  under an inactive portion of the display cover layer and may transmit and receive signals through the display cover layer. This type of configuration may allow antennas to operate, even when some or all of the structures in housing  12  are formed from conductive materials. For example, mounting the antenna structures of device  10  in region  26  under part of inactive region  20  may allow the antennas to operate even in arrangements in which some or all of the walls of housing  12  are formed from a metal such as aluminum or stainless steel (as examples). 
       FIG. 2  is a perspective view of an illustrative configuration that may be used for an antenna in device  10 . Antenna  28  may have metal traces such as traces  30  and  32  on a dielectric support structure such as dielectric support structure  46 . Metal traces such as traces  30  and  32  may be used to form an inverted-F antenna, a patch antenna, a loop antenna, an open-ended slot antenna, a closed slot antenna, an antenna having multiple branches to support multiple frequency bands of operation, a directly fed antenna, an indirectly fed antenna, a monopole antenna, a dipole antenna, or an antenna of other suitable types. 
     In the illustrative arrangement of  FIG. 2 , antenna  28  has been configured to form a loop antenna having a loop-shaped antenna resonating element structure L 2  formed from conductive traces  34 . In loop antenna resonating element L 2 , gap  40  may form a capacitor that couples opposing ends of metal traces  34 . The dimension D of structure  46  may be relatively large (e.g., more than 1 cm), so that structure  28  is elongated along longitudinal axis  42 . Because the size of conductive structures  34  (transverse to loop L 2 ) is relatively large, loop antenna  28  of  FIG. 2  may sometimes be referred to as a distributed loop antenna. If desired, other types of antenna may be used in region  26  of device  10 . The configuration of  FIG. 2  is merely illustrative. 
     Antenna  28  may be directly fed or indirectly fed. As shown in  FIG. 2 , for example, antenna  28  may be indirectly fed using near-field-coupled antenna feed structure L 1 . Antenna feed structure L 1  may be fed using antenna feed terminals  44  (e.g., a positive antenna feed terminal + and a ground antenna feed terminal −). The antenna feed terminals of antenna  28  may be coupled to radio-frequency transceiver circuitry  32  by circuitry  36 . Radio-frequency transceiver circuitry  32  may include transmitter and/or receiver circuitry configured to operate in one or more communications bands such as wireless local area network bands at frequencies such as 2.4 GHz and 5 GHz, the Bluetooth® band at 2.4 GHz, cellular telephone bands from 700 MHz to 2700 MHz or other suitable frequencies, satellite navigation system bands, etc. Circuitry  34  may include transmission line structures such as coaxial cable, microstrip transmission lines, edge coupled transmission lines, transmission lines formed from flexible printed circuit material, and cables formed on rigid printed circuit boards. Circuitry  36  may also include switches, filters, impedance matching circuits, and other circuitry. 
     Feed structure L 1  may have the shape of an inductor (e.g., a loop of conductor) or other structure that emits electromagnetic signals. Antenna resonating element structure L 2  may have a loop shape or other suitable shape that is electromagnetically coupled to feed structure L 1 . Feed structure L 1  and antenna resonating element structure L 2  may also be coupled through shared ground traces. Using near-field electromagnetic coupling from structure L 1  (i.e., an indirect feed arrangement), antenna resonating element structure L 2  may be used to transmit and/or receive wireless radio-frequency signals. 
     Dielectric support structures  46  may be formed from a dielectric such as plastic, glass, ceramic, or other dielectric material. As an example, dielectric support structures  46  may be formed from plastic that is formed using techniques such as injection molding, extrusion, and machining. If desired, support structures  46  may be hollow. In situations in which support structures  46  have an air-filled cavity, support structures  46  may have a wall of plastic or other dielectric material that extends around axis  42  under patterned conductive structures  34  and  32 . To provide structural support, one or more additional walls such as an interior wall that runs the length of structure  46  parallel to axis  42  may also be provided, if desired. 
     Antenna  28  of  FIG. 2  may support dual band operations (e.g., operations at a low band of 2.4 GHz and a high band of 5.0 GHz, or other suitable low and high communications bands). With a configuration of the type shown in  FIG. 2 , loop antenna resonating element L 2  may, as an example, exhibit a resonance at 2.4 GHz and a second harmonic resonance near 5.0 GHz. Antenna feed element L 1  may tend to exhibit a resonance at 5.0 GHz that helps enhance the performance of element L 2  at 5.0 GHz. With this type of configuration, high-band portion HB of antenna  28  may be primarily used in handling high-band signals (e.g., signals in the 5.0 GHz band) and low-band portion LB may be used in handling low band signals (e.g., signals in the 2.4 GHz band) and some high-band signals. Portion  48  of antenna  28  in high band section HB may help couple element L 1  and L 2  (and may therefore help element L 1  serve as a satisfactory feeding structure for antenna  28 ). 
     Conductive structures  34  in resonating element loop L 2  of antenna  28  may include a sheet of conductor that is wrapped around longitudinal axis  42 . During operation, antenna currents can flow within this sheet around axis  42 . In effect, sheet  34  forms a wide strip of conductor in the shape of a loop that is characterized by a perimeter. The antenna currents flowing in sheet  34  tend to lie in planes parallel to the X-Y plane of  FIG. 2 . As a result, the “loop” of loop antenna  28  effectively lies in the X-Y plane, whereas longitudinal axis  42  runs along the center of the wrapped conductive sheet (sheet  34 ) and lies parallel to the Z-axis (and perpendicular to the X-Y plane of the antenna loop). In a typical installation arrangement, longitudinal axis  42  of antenna  28  may extend parallel to an adjacent edge of housing  12  in electronic device  10 . 
     Antenna  28  may have a thin elongated shape with longitudinal dimensions that are significantly larger than lateral (transverse) dimensions. For example, length L may be greater than 1 cm, greater than 2 cm, greater than 4 cm, greater than 6 cm, 1-5 cm, 1-10 cm, less than 10 cm, 3-10 cm, or other suitable length, whereas width W may be about 1-50 mm, greater than 5 mm, 3-20 mm, 5-15 mm, 8-12 mm, or other suitable width. The magnitude of maximum thickness T may be 2-5 mm, 4-10 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, or other suitable thickness. The magnitude of MN (and therefore the minimum thickness of tail portion TP of antenna  28 ) may be, for example, 1 mm, 1.5 mm, 2 mm, or other suitable thickness. For example, MN may be 0.7-1.5 mm, 0.8 to 1.4 mm, etc. In configurations in which structure  46  is formed from a hollow plastic structure, the wall thickness of the structure may be, as an example, 0.7 to 0.9 mm, less than 1 mm, less than 2 mm, or other suitable thickness. 
       FIG. 3  is a cross-sectional side view of device  10  showing how antenna  28  may be mounted below a display cover layer in device  10  such as display cover layer  50 . Device  10  may have a display such as display  18 , as described in connection with  FIG. 1 . Display  18  may have display structures such as display structures  52  that are covered by display cover layer  50 . Display structures  52  may include a liquid crystal display module, an organic light-emitting diode array, or other types of display structures. Display structures  52  may include an array of display pixels for producing images for a user of device  10 . Display structures  52  may be mounted under display cover layer  50 . Display cover layer  50  may be formed form a transparent planar member such as a sheet of cover glass or a clear plastic layer. 
     Housing  12  may be formed from a conductive material such as metal. A conductive structure such as conductive foam  56  may be interposed between the metal traces on antenna  28  and conductive housing  12 . Conductive foam  56  may electrically short the conductive traces on antenna  28  to housing  12  (e.g., to ground housing  12 ). 
     Antenna  28  may be attached to housing  12  or other support structures. Part of antenna  28  (e.g., tail portion TP) may extend under display module  52 . Part of antenna  28  may serve as a mounting structure for components in device  10 . For example, antenna  28  may have a surface such as surface  58  that lies parallel to the innermost surface of display cover layer  50 . Adhesive  54  may be interposed between display cover layer  50  and surface  58  of antenna  28  to bond display cover layer  50  to antenna  28 . This allows antenna  28  to serve as a structural support for display cover layer  50 . Display cover layer  50  may also be attached to housing  12  (e.g., by using adhesive to attach display cover layer  50  to a portion of housing  12  that lies flush with antenna surface  58 ). By providing display cover layer  50  with additional attachment surface area using surface portion  58  on antenna  28 , the strength with which display cover layer  50  is attached to device  10  may be enhanced. Optional opaque masking layer  51  (e.g., black ink) may be formed on the underside of display cover layer  50  in inactive region  20 . 
       FIG. 4  is a perspective view of an illustrative configuration that may be used for support structures  46 . As shown in  FIG. 4 , support structures  46  may be hollow and may have walls characterized by a thickness WT. The walls of support structures  46  may surround an internal cavity (e.g., an air-filled cavity). Interior cavity features such as interior wall  60  may be used to separate the cavity into two or more smaller cavities. For example, interior support structure wall  60  may run the length of structures  46  parallel to longitudinal axis  42  and may separate the cavity in structures  46  into two respective elongated cavities such as cavity  62  and cavity  64  that run parallel to each other and parallel to longitudinal axis  42 . 
     Antenna support structures  46  may have features for mounting antenna support structures to device  10 . For example, antenna support structures  46  may have protrusions such as tabs  66 . Tabs  66  may be provided with screw holes  68 . Screws may have shafts that pass through holes  68  and heads that bear against tabs  66  to hold antenna  28  in place within housing  12 . Once antenna  28  has been attached to housing  12  in this way, antenna  28  may serve as a structural support member for additional structures in device  10 . For example, additional structures such as display cover layer  50  of display  18  ( FIG. 3 ) may be attached to surface  58  of support structure  46  to help mount these additional structures to housing  12  and device  10 . 
       FIG. 5  is a side view of a portion of device  10  showing an illustrative arrangement that may be used in mounting antenna  28  within housing  12  of device  10 . As shown in  FIG. 5 , housing  12  may have planar surfaces such as housing surfaces  59  that lie flush with planar antenna surface  58  of antenna  28  and antenna support structures  46 . Planar housing surface  59  may be formed from a ledge that is formed as an integral portion of housing  12  (e.g., a machined metal surface that is formed as an edge of a metal housing). Planar housing surface  59  may also be formed from plastic or metal support structures (e.g., internal frame members or other structure) that form internal housing structures. 
     Support structures  46  may have protruding portions  66  that are attached to housing  12  or internal structures within housing  12 . For example, adhesive, fasteners, or other attachment mechanisms may be used in attaching antenna  28  and support structures  46  to housing  12 . As shown in  FIG. 5 , for example, screws  70  may pass through openings  68  ( FIG. 4 ) in protrusions  66  and may screw into threaded holes in housing  12 , an internal frame, or other housing structure. Adhesive  54  may be used to attach planar interior surface  61  of display cover layer  50  or other planar dielectric structures to both planar outer antenna surface  58  and planar housing structure surface  59 . 
     In some configurations for antenna support structures  46 , structures  46  and antenna  28  may have an elongated shape. Due to the elongated nature of support structure  46  and antenna  28  and the relatively thin size of the walls of structure  46  in this type of configuration, it can be challenging to manufacture support structure  46 . These challenges may be addressed using injection molding techniques, extrusion techniques, techniques for machining plastic structures  46 , and other suitable manufacturing techniques. 
       FIG. 6  is an exploded perspective view of an illustrative plastic injection molding tool of the type that may be used to form antenna support structures  46 . As shown in  FIG. 6 , injection molding tool  72  may include outer mold structures such as outer mold  74  and one or more inner mold structures such as mold core structures  76 A and  76 B. During injection molding operations, mold cores  76 A and  76 B may be inserted within cavity  78  of outer mold  74  in direction  80 . When cores  76 A and  76 B are inside outer mold  74 , support structures such as pins  82  may be used to prevent cores  76 A and  76 B from flexing along their lengths. Pins  82  may pass through openings in outer mold  74  such as openings  84  and may contact cores  76 A and  76 B at locations such as locations  86 , thereby stabilizing cores  76 B and  76 A and ensuring that the thin gaps between cores  76 A and  76 B and opposing portions of outer mold  74  will be accurately maintained at their desired sizes during injection molding operations. During injection molding, plastic may be injected into gap areas  460  around the exterior of cores  76 B and  76 A and inside the interior of outer mold  74 . Gap portion  460 ′ (i.e., the gap that develops between core members  76 A and  76 B) may be used in forming internal supporting walls such as wall  60  of  FIG. 4 . 
       FIG. 7  is a cross-sectional side view of a portion of injection molding tool  72  showing how the position of a stabilizing member such as pin  82  may be adjusted using computer-controlled positioner  88 . Prior to injection molding of plastic into cavity region  460  inside mold  74 , core  76 B (and core  76 A) may be stabilized by inserting pins such as pin  82  through openings such as opening  82  using computer-controlled positioner  88 . 
     If desired, stabilizing structures such as pins  82  may be formed as integral portions of outer mold  74 . As shown in  FIG. 8 , for example, mold  74  may have an upper portion such as portion  74 A and a lower portion such as portion  74 B. Portions  74 A and  74 B may have integral pins or other integral support structures such as such as protrusions  90  to stabilize mold core structures such as cores  76 A and  76 B. If desired, molding tool  72  may have some pins that are movable using computer-controlled actuators and some pins that are formed as integral protrusions of outer mold  74 . 
     Following molding, equipment such as laser-based processing tools and other tools may be used in forming patterned conductive traces such as metal antenna traces on the exterior surface of plastic support structure  46 . For example, patterned metal foil may be laminated onto the surface of support structure  46 , etching, machining, and other patterning techniques may be used to pattern blanket metal films that have been formed on the surface of support structure  46 , or other arrangements may be used to provide patterned metal traces on the surface of support structure  46 . 
     As shown in  FIG. 9 , laser-based tools such as laser direct structuring (LDS) equipment  92  may be used to process injection molded parts such as structures  46 . Part  46  may be formed from a plastic (e.g., a plastic with an added metal complex or other suitable polymeric material) that can be selectively activated upon exposure to light. A light source such as laser  94  may generate a beam of light such as laser beam  96 . Computer-controlled positioner  98  may control the position of beam  96  relative to support structure  46 . To ensure that all sides of structure  46  can be exposed to laser beam  96 , support structure  46  may be mounted in computer-controlled rotating positioners such as rotating positioners  100 . Positioners  100  may rotate support structures  46  about axis  102 , as positioner  98  moves beam  96  relative to the surface of support structure. 
     Following selective activation of the surface of support structure  46  by selectively exposing a desired pattern on the surface of structure  46  to laser light  96 , metal traces may be grown on the surface of structure  46  Metal traces may, for example, be grown using metal deposition techniques such as electrochemical deposition (e.g., electroplating). Due to the selective surface activation of the surface of support structure  46 , the metal that is grown on support structure  46  will only be formed in the areas that were activated by exposure to laser light  96 . This allows a desired antenna pattern to be formed on the surface of support structure  46  (e.g., a pattern such as the illustrative pattern formed by traces  34  and  32  in  FIG. 2  or other suitable patterns). 
     If desired, mold cores such as mold cores  76 A and  76 B may be supported at each end using a supporting configuration of the type shown in  FIG. 10 . As shown in  FIG. 10 , mold core  76  (e.g., mold core  76 A and/or mold core  76 B) may have opposing first and second ends such as ends  76 N and  76 F. End  76 F may be supported by a support structure such as core support structure  112 . Support structure  112  may have a feature such as recess  114  or other engagement feature that is configured to removably engage with mating end  76 F of mold core structures  76 F. End  76 N of mold core  76  may be supported by support structure  104 . Support structure  104  may, if desired, be a computer-controlled positioner for moving mold core in direction  110  when it is desired to insert end  76 F of mold core  76  into recess  114  of support structure  112 . 
     Mold portion  74  and mold core  76  may form an elongated cavity such as cavity  406  in the shape of structures  46 . Following injection molding of plastic into cavity  406 , ejection plate  108  may be moved in direction  110  by computer-controlled positioner  106 , thereby removing support structure  46  from core structures  76 . As shown in  FIG. 10 , mold core  76  may be tapered so that mold core  76  is wider in the vicinity of end  76 N and is narrower in the vicinity of end  76 F to facilitate removal of support structures  46  from mold core  76 . 
     As shown in  FIG. 11 , support structure  112  may, if desired, have a feature such as protrusion  116  for mating with recess  118  in end  76 F of mold core  76 . 
       FIG. 12  is a diagram showing how mold core  76  in injection molding machine  72  may be supported using interlocking features on the ends of two mating mold core members such as left-hand mold core  76 - 1  and right-hand mold core  76 - 1 . End  76 NL of mold core  76 - 1  may be supported by a support structure such as computer-controlled positioner  104 . End  76 NR of mold core  76 - 2  may be supported by a support structure such as computer-controlled positioner  112 ′. The width of mold core  76 - 1  may taper inwardly, so that end  76 FL is narrower than end  76 NL. The width of mold core  7602  may likewise taper inwardly, so that end  76 FR is narrower than end  76 NR. Tapers on the mold core parts may help facilitate removal of the mold core parts from structures  46  following injection molding into cavity  460  between the outer mold and the mold core. 
     Interlocking (engaging) features in region  124  may be used to couple mold core  76 - 1  to mold core  76 - 2  to provide support during injection molding operations. As shown in  FIG. 12 , for example, end  76 FL may have a protrusion such as protrusion  120  that mates with a corresponding recess in opposing end  76 FR of mold core  76 - 2  such as recess  122 . Other types of engagement features may be used if desired. The illustrative configuration of  FIG. 12  is merely illustrative. 
     Because the length of each mold core in molding tool  72  of  FIG. 12  is reduced and because the engagement features in region  124  can be configured so that the mating ends of mold core structures  76 - 1  and  76 - 2  engage and support each other, the stability of the mold cores may be enhanced. In particular, for a given length of structure  46 , the use of the configuration of  FIG. 12  may help reduce the length of each individual mold core by a factor of two. For example, mold core  76 - 1  and mold core  76 - 2  may each be half as long as a single mold core such as mold core  76  of  FIG. 10 . As with the other illustrative injecting molding configurations, mold core  76 - 1  and mold core  76 - 2  of  FIG. 12  may each include two parallel elongated mold core structures for forming the parallel cavities in support structure  46 . 
     Multi-shot injection molding techniques may be used to produce plastic support structures with patterned metal traces for use in antennas such as antenna  28 . Consider, as an example, the use of molding equipment and fabrication procedures illustrated in  FIGS. 13 ,  14 ,  15 , and  16 . 
       FIG. 13  is a cross-sectional view of injection molding tool  72  in a configuration in which a cavity  460 - 1  has been formed between mold  74 - 1  and mold (core)  74 - 2 . A first shot of plastic may be injection molded into cavity  460 - 1  via injection port  126 . The first shot of plastic may be, for example, a plastic that has a high affinity to metal. 
     Following injection molding, mold core  74 - 2  may be removed. The injection molding of the first shot of plastic may form a first support structure portion such as portion  46 - 1  of  FIG. 14 . 
     As shown in  FIG. 15 , after mold core  74 - 2  has been removed from the molding tool and replaced with mold core  74 - 3 , a second shot of plastic may be injection molded on top of the first injection molded part. In particular, a second shot of plastic may be injection molded through injection molding port  128  into the cavity formed by mold core  74 - 3 , thereby forming second support structure portion  46 - 2  on first support structure portion  46 - 1 . The second shot of plastic may be formed from a material with a low affinity for metal (i.e., a metal affinity lower than that of the first shot of plastic). 
     Following formation of the second shot of plastic, support structure portions  46 - 1  and  46 - 2  may form a plastic support structure such as plastic support structure  46  of  FIG. 16 . Portion  46 - 1  has a lower affinity for metal than portion  46 - 2 , so following metal deposition with plating tool  130  or other metal coating equipment, an antenna structure such as antenna structure  134  of  FIG. 16  may be formed in which a layer of metal such as metal  132  coats the exposed surfaces of portion  46 - 1  while leaving the exposed surfaces of portion  46 - 2  uncovered by metal. Portion  46 - 1  may have a solid surface (e.g., for forming a ground plane), may have a patterned surface (e.g., for forming an antenna trace pattern for an antenna resonating element or other antenna structures), or may have other suitable shapes. In the example of  FIG. 16 , antenna structures  134  include support structure surfaces for forming metal lip  136  in metal layer  132  and have an open box shape (e.g., for forming the lower portion of hollow support structures  46  of  FIG. 2 ). Metal lip  136  may be used in soldering additional antenna structures to antenna structures  134  to form antenna structures  28 . 
     Fabrication processes such as the fabrication process illustrated in  FIGS. 13 ,  14 ,  15 , and  16  are sometimes referred to as molded interconnect device fabrication processes. Structures such as structure  134  of  FIG. 16  that have multiple shots of plastic with different metal affinities and a patterned metal coating that is patterned by patterning of the underlying shots of plastic prior to metal coating are sometimes referred to as molded interconnect devices. 
     As shown in  FIG. 17 , antenna  28  may be formed by combining molded interconnect device structures such as structure  134  of  FIG. 16  or other suitable structures with structures formed using other fabrication techniques such as structures formed using laser direct structuring (see, e.g., the laser patterned structures of  FIG. 9 ), structures formed using printed circuits, other molded interconnect device structures, etc. 
     As shown in  FIG. 17 , a plastic part such as support structure portion  46 - 3  may be selectively exposed to light in a desired pattern. For example, laser tool  140  in laser direct structuring equipment or other equipment may be used to expose a desired pattern of the surface of support structure  46 - 3  to light, thereby activating the surface for subsequent metal deposition. 
     Following selective activation using laser tool  140 , areas  142  on plastic structure  46 - 3  may be activated. Activated areas  142  may be selectively coated with metal  146  using a metal deposition tool such as electroplating tool  144 , other electrochemical deposition equipment, or other metal deposition tool. The pattern in which metal  146  is deposited on structure  46 - 3  matches the pattern in which surface  142  was patterned by exposure to laser light from laser tool  140 . Metal  146  may include portions such as lip portion  148  to facilitate subsequent attachment to other antenna structures. 
     Soldering tool  148  or equipment for depositing conductive adhesive, tools for attaching parts using fasteners, welds, or other attachment mechanisms may be used in attaching structure  46 - 3  and associated metal layer  146  to structures such as structures  134  of  FIG. 16  to form antenna structures  28 . During assembly operations, soldering tool  149  may be used to place solder paste between lip  136  of structures  134  and lip  148  of structures  46 - 3  to heat (reflow) the solder paste to form solder  150 . As shown in  FIG. 17 , solder  150  may mechanically and electrically connect structures  46 - 3  and metal layer  146  on structures  46 - 3  to structures  46 - 1  and  46 - 2  and metal  132 , thereby forming antenna structures  28 . 
     Using assembly techniques of the type shown in  FIG. 17 , molded interconnect devices (e.g., parts having multiple shots of plastic such as structures  46 - 1  and  46 - 2  with different metal affinities and having associated metal coating structures) and other types of antenna structures (e.g., structure  46 - 3  and associated patterned metal layer  146 ) may be assembled to form antenna structures  28 . It may be particularly efficient to form antenna structures from molded interconnect device structures when relatively large surface areas are to be covered (e.g., ground plane structures, larger portions of metal sheet  34  of  FIG. 2 , etc.). Laser direct structuring techniques may be particularly suitable for forming antenna structures with small metal trace features that benefit from the ability of laser direct structuring to form potentially complex patterns. Antenna structures  28  that are formed using both of these types of structures such as antenna structures  28  of  FIG. 17  may benefit from the large area efficiency of a molded interconnect device and the flexible patterning capabilities of laser direct structuring methods. 
     If desired, extrusion techniques may be used to form plastic support structures  46 .  FIG. 18  is a diagram of an extrusion tool of the type that may be used to extrude structures  46 . As shown in  FIG. 18 , extruded plastic structure  152  (e.g., an elongated strip of hollow extruded plastic) may be formed by extruding plastic material in direction  156  from opening  158  in extrusion tool  154 . 
     Die cutting or other cutting techniques may be used to cut extruded plastic member  152  into antenna-sized lengths. If desired, die cutting tools may be used to form features such as illustrative notch  162  in extruded structure  160  of  FIG. 19 . Structure  160  may be, for example, a length of strip  152  that has been cut using a die press, laser, or other cutting tool such as cutting tool  163 . 
     Extruded structures such antenna-sized extruded plastic structure  164  may also be formed using machining. For example, features such as tabs  166  and holes  168  may be formed in structure  164  using a milling machine (e.g., a CNC machine), a drill, a grinding tool, a sanding tool, or other machining tool such as machining tool  169 . 
     Illustrative steps involved in forming antenna structures such as antenna structures  28  from plastic support structures such as plastic support structures  46  are shown in  FIG. 21 . 
     At step  170 , plastic structures may be formed using tools such as extrusion tool  154 , injection molding tool  72 , or other fabrication equipment. As an example, a strip of hollow plastic structures such as structures  152  of  FIG. 18  may be extruded using extrusion tool  154  of  FIG. 18  or plastic structures  46  may be formed using injection molding equipment  72 . During injection molding operations, an injection molding core structure may be stabilized using pins, protrusions, support structures, or other stabilizing features. 
     During the operations of step  172 , optional cutting and machining operations may be performed. For example, when forming plastic structures from a strip of extruded material, it may be desirable to cut the strip of extruded material into shorter lengths (i.e., antenna-sized lengths). Die cutting, machining, laser cutting, plasma cutting, water jet cutting, hot-wire cutting, compression molding, stamping, and other fabrication techniques may be used in cutting and pattering the plastic structures with tools such as tools  163  and  169 . 
     At step  174 , optional additional antenna structures may be formed. For example, additional plastic structures such as molded interconnect device structures may be formed by coating multiple shots of plastic with different metal affinities with a layer of metal, using laser direct structuring techniques and other patterning techniques to form dielectric substrates with patterned metal antenna traces, and otherwise forming one or more plastic structures for use with the structures formed using the operations of steps  170  and  172 . 
     The optional structures formed during the operations of step  174  may be attached to the structures formed during steps  170  and  172  using soldering (see, e.g., soldering tool  148  and solder  150  of  FIG. 17 ), thereby forming antenna structures  28 . 
     At step  178 , the antenna structures may be mounted in device housing  12 . For example, screws may be passed through screw holes and used to screw antenna structures  28  into place in housing  12  in device  10 . After mounting antenna structures  28  to housing  12 , adhesive may be placed on surfaces such as antenna surface  58 . Display cover layer  50  may then be mounted in device housing  12 . During the mounting of display cover layer  50 , the presence of the adhesive between display cover layer  50  and surface  58  of antenna  28  may help hold display cover layer  50  in place in device  10 . 
     If desired, antenna structures  28  may be formed using injection molding without using laser direct structuring. As an example, antenna structures  28  may be formed using multiple shots of plastic with different metal affinities that are coated with metal without attaching laser direct structuring parts or other parts (e.g., using techniques of the type shown in  FIGS. 13 ,  14 ,  15 , and  16 ). 
     Antenna structures  28  may also be formed using laser direct structuring techniques (e.g., laser patterning to activate the surface of an injection molded structure or extruded structure) without using molded interconnect device fabrication techniques (e.g., by patterning structures  46  using the equipment of  FIG. 9  and metal coating equipment). 
     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: 20120606
Publication Date: 20151117
Grant Date: 20151117
Priority Date: 20120606
Inventors: GUTERMAN JERZY
HAYLOCK JONATHAN
SHIU BOON W.
JEZIOREK PETER
IRCI ERDINC
ZHU JIANG
PASCOLINI MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "B29C45/14639", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C45/0055", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C2045/0058", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C33/76", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C45/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C45/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C2045/0058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C33/76", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C45/14639", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C45/0055", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 48537020