PATENT DOCUMENT

Publication Number: US-9865915-B2
Application Number: US-201313780787-A
Country: US
Kind Code: B2

Title: Electronic device with diverse antenna array having soldered connections

Abstract:
A wireless electronic device may be provided with antenna structures. The antenna structures may be formed from an antenna ground and an array of antenna resonating elements. The antenna resonating elements may be electrically connected to the antenna ground using solder. The antenna resonating elements may be formed from metal traces on a dielectric support structure that surrounds the antenna ground. The antenna ground may be formed form stamped sheet metal and may have slanted steps adjacent to the antenna resonating elements. To form a solder joint between the metal antenna resonating element traces and the sheet metal of the antenna ground, laser light may be applied to the sheet metal of the antenna ground in the vicinity of the solder paste. Separate metal members may also be provided in the vicinity of the solder paste and may be heated using the laser to join metal traces on plastic carriers.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a layer of metal that forms an antenna ground; 
 antenna resonating element traces supported by a dielectric, wherein each of the antenna resonating element traces and the antenna ground form a respective antenna in an array of antennas; 
 and 
 solder that connects the antenna resonating element traces to the antenna ground, wherein the array of antennas comprises six antennas, at least some of the antennas have different electric field polarizations, at least three of the antennas are configured to transmit and receive radio-frequency signals in at least a 5 GHz communications band, and at least three of the antennas are configured to transmit and receive radio-frequency signals in at least a 2.4 GHz communications band. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the layer of metal that forms the antenna ground comprises sheet metal. 
     
     
       3. The apparatus defined in  claim 2  wherein the dielectric comprises a plastic carrier. 
     
     
       4. Apparatus, comprising:
 sheet metal that forms an antenna ground; 
 a ring shaped plastic carrier that surrounds the sheet metal and that has antenna resonating element traces, wherein each of the antenna resonating element traces and the antenna ground form a respective antenna in an array of antennas; and 
 solder that connects the antenna resonating element traces to the sheet metal that forms the antenna ground. 
 
     
     
       5. The apparatus defined in  claim 4  wherein the array of antennas comprises six antennas. 
     
     
       6. The apparatus defined in  claim 5  wherein at least some of the antennas have different electric field polarizations. 
     
     
       7. The apparatus defined in  claim 6  wherein at least three of the antennas are configured to transmit and receive radio-frequency signals in at least a 5 GHz communications band and wherein at least three of the antennas are configured to transmit and receive radio-frequency signals in at least a 2.4 GHz communications band. 
     
     
       8. The apparatus defined in  claim 5  further comprising:
 radio-frequency transceiver circuitry coupled to the array of antennas; and 
 storage and processing circuitry coupled to the radio-frequency transceiver circuitry. 
 
     
     
       9. The apparatus defined in  claim 8  wherein the storage and processing circuitry and the radio-frequency transceiver circuitry are configured to perform wireless base station operations and the storage and processing circuitry includes a mass storage device having a capacity of at least 256 GB. 
     
     
       10. The apparatus defined in  claim 2 , wherein the sheet metal comprises stamped sheet metal. 
     
     
       11. The apparatus defined in  claim 10 , wherein the stamped sheet metal has a planar portion, a first slanted portion that is bent at a non-zero angle with respect to the planar portion, a second slanted portion that is bent at a non-zero angle with respect to the planar portion, and the planar portion is interposed between the first and second slanted portions. 
     
     
       12. Apparatus, comprising:
 stamped sheet metal that forms an antenna ground; 
 dielectric support structures having antenna resonating element traces, wherein each antenna resonating element trace and the antenna ground form a respective antenna in an array of antennas; 
 solder that connects the antenna resonating element traces to the stamped sheet metal that forms the antenna ground, wherein the stamped sheet metal has a planar portion, a first slanted portion that is bent at a non-zero angle with respect to the planar portion, and a second slanted portion that is bent at a non-zero angle with respect to the planar portion, and the planar portion is interposed between the first and second slanted portions; and 
 a conductive bracket, wherein the planar portion is mounted to the conductive bracket and is electrically shorted to the conductive bracket. 
 
     
     
       13. The apparatus defined in  claim 12 , further comprising:
 storage circuitry mounted within the conductive bracket and below the planar portion of the stamped sheet metal. 
 
     
     
       14. The apparatus defined in  claim 12 , the stamped sheet metal further comprising:
 an additional planar portion, wherein the first and second slanted portions are both interposed between the planar portion and the additional planar portion, and the dielectric support structures completely surround the additional planar portion. 
 
     
     
       15. The apparatus defined in  claim 14 , further comprising:
 housing structures, wherein the stamped sheet metal, the dielectric support structures, the conductive bracket, and the solder are each enclosed within the housing structures. 
 
     
     
       16. The apparatus defined in  claim 15 , wherein the housing structures comprise a wall structure, the planar portion and the additional planar portion of the stamped sheet metal each extend parallel to the wall structure, the planar portion is formed at a first distance from the wall structure, and the additional planar portion is formed at a second distance from the wall structure that is greater than the first distance. 
     
     
       17. The apparatus defined in  claim 11 , further comprising:
 radio-frequency transceiver circuitry; and 
 a plurality of coaxial cables each having a corresponding radio-frequency connector structure that is coupled to the radio-frequency transceiver circuitry. 
 
     
     
       18. The apparatus defined in  claim 17 , wherein the first and second portions of the stamped sheet metal comprise a plurality of openings through which the plurality of coaxial cables pass, wherein each coaxial cable of the plurality of coaxial cables is coupled to a respective antenna resonating element trace in the array of antennas through a respective opening of the plurality of openings. 
     
     
       19. The apparatus defined in  claim 11 , wherein the antenna resonating element traces comprise first, second, third, and fourth antenna resonating element traces, the first and second resonating element traces each extend in a first direction, and the third and fourth resonating element traces each extend in a second direction that is perpendicular to the first direction. 
     
     
       20. The apparatus defined in  claim 19 , wherein the stamped sheet metal has first, second, third, and fourth peripheral edges, the first and second peripheral edges extend between and perpendicular to the third and fourth peripheral edges, the solder connects the first antenna resonating element trace to the third peripheral edge, the solder connects the second antenna resonating element trace to the fourth peripheral edge, the solder connects the third antenna resonating element trace to the first peripheral edge, the solder connects the fourth antenna resonating element trace to the second peripheral edge, the second antenna resonating element trace is configured to resonate in a first radio-frequency communications band, and the fourth antenna resonating element trace is configured to resonate in a second radio-frequency communications band that is different from the first radio-frequency communications band.

Description:
BACKGROUND 
     This relates to wireless electronic devices and, more particularly, to forming and using antenna arrays for wireless electronic devices. 
     Electronic devices such as computers, media players, cellular telephones, wireless base stations, and other electronic devices often contain wireless circuitry. For example, cellular telephone transceiver circuitry or wireless local area network circuitry may be used to allow a device to wirelessly communicate with external equipment. Antenna structures in the wireless circuitry may be used in transmitting and receiving wireless signals. 
     It can be challenging to incorporate wireless circuitry such as antenna structures into an electronic device. Space is often at a premium, particularly in compact devices. There may be a desire to incorporate more than one antenna into a device, but care must be taken to ensure that the antennas do not interfere with each other and to ensure that antenna structures can be manufactured in satisfactory volumes during production of the electronic device. 
     It would therefore be desirable to be able to provide improved electronic device antenna structures. 
     SUMMARY 
     An electronic device may contain storage and processing circuitry and input-output circuitry such as wireless communications circuitry. The wireless circuitry may include a radio-frequency transceiver coupled to antenna structures. The radio-frequency transceiver circuitry may support communications in communications bands such as cellular telephone communications bands and wireless local area network bands. 
     The antenna structures may be formed from an antenna ground and an array of antenna resonating elements that share the antenna ground. There may be, for example, six antenna resonating elements for forming an array of six respective antennas around the periphery of the antenna ground. The electric field polarizations of at least some of the antennas may be different. Providing the antenna array with polarization diversity may enhance antenna performance. 
     The antenna resonating elements may be formed from metal traces on a dielectric support structure that surrounds the antenna ground. The antenna ground may be formed form stamped sheet metal and may have slanted steps adjacent to the antenna resonating elements. 
     The antenna resonating elements may be electrically connected to the antenna ground using solder. To form a solder joint between the metal antenna resonating element traces and the sheet metal of the antenna ground, laser light may be applied to the sheet metal of the antenna ground in the vicinity of the solder paste. When joining metal traces on a pair of respective plastic carriers, a separate metal member may be provided in the vicinity of the solder paste. The solder paste in this type of joint may be heated by applying laser light to the metal member. 
     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 containing wireless circuitry in accordance with an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of an illustrative electronic device containing wireless circuitry and associated external equipment that may wirelessly communicate with the electronic device over a wireless communications path in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional top view of an illustrative electronic device of the type shown in  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device of the type shown in  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 5  is a diagram of an illustrative antenna of the type that may be used in forming an antenna array with multiple antennas in a wireless electronic device in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of a portion of an antenna ground structure and an associated antenna resonating element being used to form an antenna in a wireless electronic device in accordance with an embodiment of the present invention. 
         FIG. 7  is a top view of an antenna array formed from an antenna ground plane and an array of antenna resonating elements surrounding the ground plane in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of structures such as antenna structures being soldered together using laser heating of a metal structure in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional side view of structures such as antenna structures having metal traces on plastic carriers being soldered together by applying laser light to a metal member embedded within solder paste in accordance with an embodiment of the present invention. 
         FIG. 10  is a flow chart of illustrative steps involved in forming structures such as antenna structures with solder joints by applying laser light to metal structures at the joints in accordance with an embodiment of the present invention. 
         FIG. 11  is a bottom perspective view of an illustrative stamped metal antenna can of the type that may be used in forming antenna ground structures for the electronic device of  FIG. 1  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Wireless electronic devices such as wireless electronic device  10  of  FIG. 1  may contain wireless circuitry. The wireless circuitry of wireless electronic device  10  may include radio-frequency transceiver circuitry and associated antenna structures for transmitting and receiving wireless signals. Electronic device  10  may be a handheld electronic device such as a portable media player or cellular telephone, may be a portable computer such as a tablet computer or laptop computer, may be a desktop computer, may be a television, may be a wireless access point or other wireless base station, may be a computer monitor, may be a set-top box, may be a gaming console, or may be other electronic equipment. Illustrative configurations in which wireless electronic device  10  is a wireless base station such as a wireless base station that serves as a wireless access point for a wireless local area network and that may be provided with a hard drive or other mass storage device are sometimes described herein as an example. 
     As shown in  FIG. 1 , electronic device  10  may have a housing such as housing  12 . Housing  12  may be formed from one or more housing structures. Housing  12  may include metal structures, plastic structures, glass structures, ceramic structures, and structures formed from other materials. Housing  12  may, if desired, be formed using a unibody construction in which housing  12  or substantially all of housing  12  is formed from a single machined piece of material. Housing  12  may also be formed by joining two or more parts (e.g., first and second housing members, internal housing frame structures, etc.). To allow antennas to operate satisfactorily, the walls of housing  12  may be formed from a dielectric such as plastic or one or more dielectric antenna window structures may be formed in a conductive housing  12 . As an example, the top and four sides of housing  12  may be formed form plastic. 
     Device  10  may include antenna structures and additional electrical components. The antenna structures may be located in an upper portion of housing  12  such as upper portion  16 . The antenna structures may include one or more antennas that are used to wirelessly transmit and receive signals for device  10 . Antenna structures in device  10  may, for example, include multiple antennas organized to form a multiple antenna array. The antenna array may be used for implementing wireless communications schemes such as MIMO (multiple input multiple output) schemes. 
     The additional electrical components may be located in a lower portion of housing  12  such as lower portion  18 . Device  10  may be coupled to a source of alternating current line power or a source of direct current power. For example, device  10  may receive alternating current power through electrical cord  20  and plug  32 . Plug  32  may have prongs  34  that fit into a wall outlet. 
     Device  10  may include data ports, buttons, and other components. Such components may be mounted in a region of device  10  such as region  14  of  FIG. 1 . Buttons may be used for turning on and off device  10 , for making settings adjustments when using device  10 , and for otherwise facilitating user interactions with device  10 . Openings may be formed in the housing wall of device  10  in region  14  of housing  12  or other suitable region to accommodate ports such as audio jacks, digital data ports, etc. Status indicator lights and other input-output devices may also be incorporated in device  10  in a region such as region  14 , if desired. 
       FIG. 2  is a schematic diagram showing illustrative components that may be included in an electronic device such as electronic device  10  of  FIG. 1 . As shown in  FIG. 2 , electronic device  10  may include control circuitry such as storage and processing circuitry  36  and may include associated input-output circuitry  38 . 
     Control circuitry  36  may include storage and processing circuitry that is configured to execute software that controls the operation of device  10 . Control circuitry  36  may include microprocessor circuitry, digital signal processor circuitry, microcontroller circuitry, application-specific integrated circuits, and other processing circuitry. Control circuitry  36  may also include storage such as volatile and non-volatile memory, hard-disk storage, removable storage, solid state drives, random-access memory, memory that is formed as part of other integrated circuits such as memory in a processing circuit, etc. 
     Input-output circuitry  38  may include components for receiving input from external equipment and for supplying output. For example, input-output circuitry  38  may include user interface components for providing a user of device  10  with output and for gathering input from a user. As shown in  FIG. 2 , input-output circuitry  38  may include wireless circuitry  52 . Wireless circuitry  52  may be used for transmitting and/or receiving signals in one or more communications bands such as cellular telephone bands, wireless local area network bands (e.g., the 2.4 GHz and 5 GHz IEEE 802.11 bands), satellite navigation system bands, etc. For example, when device  10  is used as a wireless base station, wireless circuitry  52  may support 2.4 GHz and 5 GHz IEEE 802.11 wireless local area network communications. 
     Wireless circuitry  52  may include transceiver circuitry such as radio-frequency transceiver  40 . Radio-frequency transceiver  40  may include a radio-frequency receiver and/or a radio-frequency transmitter. Radio-frequency transceiver circuitry  40  may be used to handle wireless signals in communications bands such as the 2.4 GHz and 5 GHz WiFi® bands, cellular telephone bands, and other wireless communications frequencies of interest. 
     Radio-frequency transceiver circuitry  40  may be coupled to one or more antennas in antenna structures  44  using transmission line structures such as transmission lines  42 . Transmission lines  42  may include coaxial cables, microstrip transmission lines, transmission lines formed from traces on flexible printed circuits (e.g., printed circuits formed from flexible sheets of polyimide or other layers of flexible polymer), transmission lines formed from traces on rigid printed circuit boards (e.g., fiberglass-filled epoxy substrates such as FR4 boards), or other transmission line structures. If desired, circuitry may be interposed within transmission line structures  42  such as impedance matching circuitry, filter circuitry, switches, and other circuits. This circuitry may be implemented using one or more components such as integrated circuits, discrete components (e.g., capacitors, inductors, and resistors), surface mount technology (SMT) components, or other electrical components. 
     Antenna structures  44  may include inverted-F antennas, patch antennas, loop antennas, monopoles, dipoles, or other suitable antennas. Configurations in which at least one antenna in device  10  is formed from an inverted-F antenna structure are sometimes described herein as an example. Wireless circuitry  52  may use antenna structures  44  to transmit and receive wireless signals such as wireless signals  48 , thereby allowing device  10  to communicate with external equipment  50 . External equipment  50  may be a handheld electronic device such as a portable media player or cellular telephone, may be a portable computer such as a tablet computer or laptop computer, may be a desktop computer, may be a television, may be a wireless access point or other wireless base station, may be a computer monitor, may be a set-top box, may be a gaming console, or may be other electronic equipment. For example, if electronic device  10  has been configured to serve as a wireless base station, external equipment  50  may be one or more tablet computers, cellular telephones, portable computers, desktop computers, media player equipment, and other equipment that communicates with the wireless base station using wireless signals  48 . 
     Input-output circuitry  38  may include buttons and other components  46 . Components  46  may include buttons such as sliding switches, push buttons, menu buttons, buttons based on dome switches, keys on a keypad or keyboard, or other switch-based structures. Components  46  may also include sensors, displays, speakers, microphones, cameras, status indicators lights, etc. 
     A cross-sectional top view of device  10  of  FIG. 1  taken along line  24  and viewed in direction  26  of  FIG. 1  is shown in  FIG. 3 . As shown in  FIG. 3 , housing  12  may have a rectangular outline. Storage such as a hard drive, a solid state drive, or other mass storage device may be mounted within diagonal region  56 . The mass storage device may be used to store large amounts of data (e.g., more than 256 GB, more than 1 TB, etc.). Region  58  may contain power supply circuitry, a fan, control circuitry  36  and input-output circuitry  38  of  FIG. 2 , and other electrical components. Region  54  may contain a heat sink. For example, metal heat sink fins that are used in cooling the hard drive or other storage of region  56  and/or the circuitry of region  58  may be installed in region  54 . 
     A cross-sectional side view of device  10  of  FIG. 1  taken along line  20  of  FIG. 1  and viewed in direction  22  is shown in  FIG. 4 . As shown in  FIG. 4 , the components of device  10  may be mounted within the interior of device housing  12 . Hard disk drive  60  or other storage components may, if desired, be mounted within bracket  62  in region  56 . Antenna structures  44  may include antenna ground structure  64  and antenna resonating elements  66 . Bracket  62  may be a metal bracket. Antenna ground structures  54  may be formed from a stamped sheet metal part that is mounted to metal bracket  62 . Antenna ground structures  54  may be grounded to a source of ground potential by virtue of being electrically shorted to metal bracket  62 , which may be grounded. 
     Antennas in an antenna array for device  10  may be formed by mounting antenna resonating elements  66  within the vicinity of antenna ground structures  64 . Antenna ground structures  64  may sometimes be referred to as an antenna can or grounding can or may be referred to as a shared antenna ground in scenarios such as those in which structures  64  form a common ground for each of antenna resonating elements  66 . Portions of antenna resonating elements  66  may be shorted to antenna ground structures  64  using solder or other electrical paths. 
     Antenna resonating elements  66  may be based on patch antenna resonating elements, loop antenna resonating elements, monopole antenna resonating elements, dipole antenna resonating elements, planar inverted-F antenna resonating elements, slot antenna resonating elements, other antenna resonating elements, or combinations of these antenna resonating elements. As an example, antenna resonating elements  66  may be inverted-F antenna resonating elements that are used in forming an array of inverted-F antennas for device  10 . 
       FIG. 5  is a diagram of an illustrative inverted-F antenna  70  formed from inverted-F antenna resonating element  66  and antenna ground  64 . Antenna ground  64  may be a stamped metal ground structure such as antenna ground  64  of  FIG. 4 . Antenna resonating element  66  may be a single arm or multi-arm inverted-F antenna resonating element that is mounted adjacent to antenna ground structures  64  as shown in  FIG. 4 . 
     As shown in  FIG. 5 , antenna resonating element  66  may have a main resonating element arm such as arm  72 . Short circuit branch  74  may be coupled between arm  72  and ground  64 . Antenna feed branch  76  may be coupled between arm  72  and ground  64  in parallel with short circuit branch  74 . Antenna feed branch  76  may form an antenna feed that includes a positive antenna feed terminal (+) and a ground antenna feed terminal (−). A positive transmission line conductor in transmission line structures  42  may be coupled between a positive terminal in radio-frequency transceiver circuitry  40  and positive antenna feed terminal (+). A ground transmission line conductor in transmission line structures  42  may be coupled between a ground terminal in radio-frequency transceiver circuitry  40  and ground antenna feed terminal (−). 
     Resonating element arm  72  may have a single branch or may have a longer branch that is associated with a low band resonance and a shorter branch that is associated with a high band resonance (as an example). Configurations in which inverted-F antenna has three or more different resonating element branches may also be used. The single-arm configuration of antenna resonating element  66  of  FIG. 5  is merely illustrative. 
     Antenna ground structures  64  may be formed from a stamped sheet metal part that is oriented horizontally, as shown in  FIG. 4 . To help avoid undesired reflection-induced resonances in wireless performance and thereby improve antenna performance, it may be desirable to form at least some of the surfaces of antenna ground structures  64  with angles (i.e., with slanted surfaces that form diagonal steps between different ground plane regions). As shown in  FIG. 6 , for example, the sheet metal that is used in forming antenna ground structures  64  may be stamped to form planar horizontal portions such as horizontal portions  78  and  82  and angled portions such as angled portion  80 . Angled surfaces  80  may help reduce the possibility of creating undesired standing wave reflections in the antennas of device  10  and may help evenly distribute the signals from the antennas of device  10 , improving antenna performance while satisfying regulatory requirements for emitted signal levels. 
     As shown in  FIG. 6 , the surfaces of angled (slanted step) portion  80  may be oriented at a 45° angle with respect to horizontal surfaces such as surfaces  78  and  82 . Angled surfaces in antenna ground structures  64  may be oriented at other angles (e.g., angles of more than 45° or less than 45°) with respect to horizontal surfaces such as surfaces  78  and  82 , if desired. The configuration of  FIG. 6  is merely illustrative. 
     A top view of antenna structures  44  is shown in  FIG. 7 . As shown in  FIG. 7 , antenna structures  44  may include antenna ground structures  64  with an approximately footprint (e.g., a structure with a peripheral edge that outlines an approximately rectangular shape). Multiple antenna resonating elements  66  may be arranged around the periphery of antenna ground structures  64 . There may be, for example, an array of six antennas  70  in antenna structures  44 . In this type of configuration, three of the antennas may be configured to transmit and receive wireless signals in at least a 2.4 GHz wireless local area network communications band and another three of the antennas may be configured to transmit and receive wireless signals in at least a 5 GHz wireless local area network communications band. 
     In each antenna  70 , short circuit branch  74  may be used to couple main resonating element arm  72  to antenna ground  64 . Each antenna has an associated antenna feed formed from positive (+) and ground (−) antenna feed terminals. The positive and ground antenna feed terminals of each antenna feed may be coupled to transmission line structures  42  such as coaxial cables. For example, the antenna feed terminals of each antenna  70  of  FIG. 7  may be coupled to a printed circuit board on which components for radio-frequency transceiver circuitry  40  have been mounted using a respective coaxial cable. 
     Because the inverted-F antenna resonating elements  66  are oriented in different directions in the configuration of  FIG. 7 , antennas  70  exhibit different polarizations, as indicated by the electric fields E associated with each antenna  70  in  FIG. 7 . Placement of antennas  70  within antenna structures  44  so that antennas  70  exhibit different polarizations helps improve wireless signal uniformity and reduces electromagnetic coupling between antennas  70 , thereby improving performance of the antenna array (e.g., when handling MIMO signals). Electromagnetic coupling can also be reduced by ensuring that adjacent antennas such as antennas A 1  and A 2  operate in different bands. 
     The center of antenna structures  44  may be formed from a metal sheet with an approximately rectangular outline (i.e., antenna ground  64 ). Dielectric support structure  84  may surround the periphery of antenna ground  64 . For example, dielectric support structures  84  may have the shape of a strip of dielectric material that runs along the edges of antenna ground  64 , so that the strip of dielectric material forms a ring-shaped dielectric member. Adhesive, fasteners, solder, overmolding, engagement features, or other attachment mechanisms may be used in attaching dielectric support structures  84  to antenna ground structures  64 . Because dielectric support structures  84  may be used in supporting antenna resonating elements  66  for antennas  70 , dielectric support structures  84  are sometimes referred to as dielectric carriers, a dielectric support member, an antenna support structure, an antenna support, or an antenna resonating element support member (as examples). 
     Antenna resonating elements  66  may be formed using conductive structures such as patterned metal foil or metal traces on a dielectric substrate. Metal traces may be patterned using selective laser surface activation followed by electroplating (sometimes referred to as laser direct structuring), by blanket metal deposition using physical vapor deposition equipment or electrochemical deposition followed by photolithographic patterning, by screen printing, etc. The conductive structures of antenna structures  66  may be supported by glass ceramic carriers, plastic carriers, printed circuits, or other dielectric support structures such as dielectric support structures  84 . Conductive materials for antenna resonating elements  66  may, for example, be supported on dielectric supports  84  such as injection-molded plastic carriers, glass or ceramic members, or other insulators. 
     In a configuration in which antenna resonating elements are formed from metal traces on dielectric support structure  84  and in which antenna ground  64  is formed from a stamped sheet metal structure, solder may be used in forming electrical connections  86  between antenna resonating elements  66  and antenna ground. 
     Metal traces are typically relatively thin (e.g., less than 100 microns thick, less than 10 microns thick, or less than 1 micron thick). To avoid damaging metal traces on a dielectric carrier during soldering operations, it may be desirable to apply heat to a solder joint indirectly. For example, solder paste at a joint associated with electrical connections  86  may be heated by heating sheet metal structures or other structures that are thicker than metal traces. As shown in  FIG. 8 , for example, laser  88  may be used to generate laser light  90  that is applied to portion  92  of a metal structure such as a sheet metal structure forming antenna ground  64  (e.g., a metal member that is thicker than conductive trace  66  on dielectric support structure  84 ). 
     Solder joint  94  of  FIG. 8  may be used in forming electrical connection  86  between antenna resonating element  66  (or other conductive structures) and antenna ground  64  (or other conductive structures). Antenna resonating element  66  is formed from a metal trace on the surface of dielectric support structures  84 . Initially, a layer of solder paste may be interposed between portion  92  of metal antenna ground structure  64  and portion  96  of the trace forming antenna resonating element  66  on dielectric support structure  84 . The layer of solder paste may be converted into a solder joint by applying heat to portion  92  and thereby reflowing the solder paste. 
     To avoid damage to sensitive structures such as the thin layer of metal forming portion  96  of the metal trace of antenna resonating element  66 , laser  88  may be used to apply light  90  directly to portion  92  of metal antenna ground  64 , rather than to the solder paste, the trace forming antenna resonating element  66 , or potentially sensitive dielectric support structure  84 . 
     Laser light  90  may have any suitable wavelength. For example, laser  88  may be an infrared laser such as a CO 2  laser and laser light  90  may be infrared light to minimize reflections from the metal of portion  92  of antenna ground  64 . When laser light  90  from laser  88  is applied to portion  92  of a metal structure such as a metal sheet or other metal part forming antenna ground  64 , portion  92  will rise in temperature. The heat from portion  92  will be thermally conducted to the solder paste under portion  92 , thereby reflowing the solder paste to form solder  94  for electrical connection  86  between antenna ground  64  and antenna resonating element  66 . 
     If desired, an additional piece of metal may be placed against the solder paste to serve as a heating element for the solder paste. This type of configuration is shown in the cross-sectional side view of  FIG. 9 . In the  FIG. 9  example, electrical connection  86  is being formed between respective metal traces  102  and  104 . Metal trace  102  may be a patterned trace formed on a dielectric carrier such as dielectric support structures  100 . Metal trace  104  may be a patterned trace formed on a dielectric carrier such as dielectric support structures  106 . Dielectric support structures  100  and  106  may be plastic such as injection molded plastic or other dielectric such as glass, ceramic, etc. Metal traces  102  and  104  may be used to form antenna structures  44  or other conductive structures. Metal member  108  may be a strip of metal, a circular or oval rod of metal, other elongated metal members, or metal structures having other suitable shapes. The thickness of metal member  108  is preferably greater than the thickness of metal traces  102  and  104 . 
     Metal member  108  is separate from metal traces  102  and  104  and is preferably embedded fully or partially within solder paste for forming solder joint  94 . When it is desired to reflow the solder paste to form a solder joint between metal traces  102  and  104  and thereby form electrical connection  86  between traces  102  and  104 , laser  88  may apply light such as infrared laser light  90  directly to metal member  108 . Laser light  90  need not strike adjacent structures metal traces  102  and  104 . Metal member  108  may absorb the infrared light that is applied, causing the temperature of metal member  108  to rise and heat the adjacent solder paste to form solder joint  94 . 
     If desired, other types of parts may be joined using separate metal members such as illustrative member  108  of  FIG. 9 . For example, a pair of metal parts may be joined using a separate metal member such as metal member  108 . The metal structures that are being joined may be antenna resonating elements  66 , antenna ground structures  64 , or other conductive components. 
     Illustrative steps involved in forming electrical connections  86  are shown in  FIG. 10 . Initially, metal traces may be patterned onto dielectric support structures. For example, laser light may be applied to selected portions of the surface of a plastic carrier (e.g., a plastic carrier containing metal particles). The laser light is applied at step  120 , which activates the illuminated areas without activating the unilluminated areas. Metal plating techniques (step  122 ) may then be used to form metal traces on the dielectric support structures (e.g., traces for forming antenna resonating elements  66  or other structures on substrates such as dielectric support structures  84 ). The process of using laser light activation (step  120 ) and subsequent electroplating (step  122 ) to form patterned metal traces on the dielectric support structure is merely illustrative. Any suitable technique for forming patterned metal traces on a plastic carrier or other dielectric structure may be used if desired. 
     Following formation of patterned metal traces and formation of any additional parts to be joined with a solder joint (e.g., following metal stamping or other techniques to form a stamped metal sheet for antenna ground structures  64 ), a needle-based application tool, screen printing equipment, or other equipment may be used to dispense solder paste onto the structures to be joined. Solder paste may be applied along appropriate portions of the edge of antenna ground structures  64  or other sheet metal structure and/or may be applied along corresponding mating edge portions of dielectric support structures  84  (e.g., after antenna resonating element traces have been formed on the surface of dielectric support structures  84 ). In scenarios of the type shown in  FIG. 9  in which metal traces on two plastic parts are being joined, one or more elongated metal members may be incorporated into the solder paste. 
     At step  126 , after the joint in the parts to be joined has been provided with solder paste and has been provided with the optional elongated metal member, laser light such as infrared laser light may be applied to the metal structures at the joint. For example, the laser light may be applied to a portion of the metal of the part being joined such as portion  92  of metal antenna ground  64  of  FIG. 8  and/or may be applied to the separate elongated metal strip in the solder paste such as metal member  108  of FIG.  9 ). The applied laser light heats the metal and reflows the solder that is adjacent to the metal. The molten solder forms a solder joint between the metal traces on the dielectric carrier and the metal traces on another dielectric carrier (see, e.g.,  FIG. 8 ) or forms a solder joint between the metal traces on the dielectric carrier and a corresponding portion of a metal structure (see, e.g., metal antenna ground structure  64  of  FIG. 9 ). 
       FIG. 11  is a bottom perspective view of illustrative antenna structures  44  using a process of the type shown in  FIG. 10 . In the orientation of  FIG. 11 , the antenna resonating element structures  66  are formed on the far side of dielectric support structures  84 . Dielectric support structures  84  surround peripheral edge of antenna ground structures  64 . As described in connection with  FIG. 6 , antenna ground structures  64  may be formed from a stamped sheet of metal having slanted steps such as slanted (angled) surface  80 . Openings  130  may be formed to allow coaxial cables  42  to penetrate from one side of antenna ground structures  64  to the other. When assembled into device  10 , connectors  132  at the end of each coaxial cable mate with corresponding printed circuit board connectors in transceiver circuitry  40 . 
     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. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20130228
Publication Date: 20180109
Grant Date: 20180109
Priority Date: 20130228
Inventors: SHIU BOON W.
GUTERMAN JERZY
PASCOLINI MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 51387607