Abstract:
A stamped antenna and a method of manufacturing includes providing a sheet of metallic material for a first partial stamping. The first partial stamping forms an antenna including traces, contacts, carriers connected to the traces, and tie-bars between the traces. A pressure sensitive adhesive is then bonded to the traces of the antenna. A second complete stamping is then performed on the antenna, including pressure sensitive adhesive, to remove the carriers and tie-bars. An intermediate product for the manufacture of an antenna includes a pressure sensitive adhesive, one or more stamped traces bonded with the pressure sensitive adhesive, and at least one tie-bar connected between the one or more traces supports the one or more traces.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a stamped antenna and a method of manufacturing a stamped antenna, and more specifically, to a method of manufacturing an antenna that includes a first partial initial stamping of the antenna from a sheet of metal, and a subsequent complete stamping of the antenna. 
         [0003]    2. Related Art 
         [0004]    As communication technology continues to advance, the use of antennas is becoming more widespread and possible applications are broadening. Various types of antennas are not only used for large scale communication, but also for small scale communication between devices for identification purposes and even for electronic device charging. 
         [0005]    Near field communication (NFC) devices are becoming popular for transferring data between two devices that are in proximity of each other. NFC establishes a radio connection between two devices having a NFC antennas, such as smart phones, as well as NFC tags, which are unpowered devices that contain a NFC chip having a NFC antenna. NFC devices, when in close proximity, can engage in two-way communication with one another. This two-way communication allows the devices to transfer data back and forth. Additionally, a NFC device can engage in one-way communication with a NFC tag, such that the NFC device can obtain data from the tag, but cannot transfer information to the tag. NFC tags can be employed for managing the inventory and sale of a wide variety of goods, as well of identification of data pertaining to goods. Accordingly, NFC tags may be used for retaining data that a user can obtain through engaging the tag with a NFC device. 
         [0006]    Similarly, radio frequency identification (RFID) tags are finding increased and widespread use as more systems are developed and placed into service for managing the inventory and sale of a wider variety of goods. These RFID tags are applied to the goods and employ electronic circuitry responsive to radio frequency (RF) signals for providing readily monitored identification data relating to the goods. 
         [0007]    NFC devices, NFC tags, and RFID tags all include an antenna connected to other circuit components. Because there is pressure to keep devices small, it follows that it is desirable that the antennas for these devices are compact and thin, resulting in antennas having thin widths, and narrow traces with small spacing between the traces. As technology advances, the desire for even more compact articles carrying NFC and RFID antennas increases. 
         [0008]    NFC and RFID antennas typically occupy a substantial portion of the area dimensions of the article employing the antenna, and are often constructed of a relatively thin copper foil for flexibility and for maximum effectiveness. Many antennas are currently manufactured by a process involving photochemical etching. The photochemical etching process can often be expensive compared to other metal working techniques. 
         [0009]    Accordingly, what would be desirable, but has not yet been provided, is an improved antenna and method of manufacturing. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention relates to a stamped antenna and a method of manufacturing. A sheet of metallic material is provided and a first partial stamping is performed on the metallic material. The first partial stamping forms an antenna including traces, contacts, carriers connected to the traces, and tie-bars between the traces. A pressure sensitive adhesive is then bonded to the traces of the antenna. A second complete stamping is then performed on the antenna, including pressure sensitive adhesive, to remove the carriers and tie-bars. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The foregoing features of the disclosure will be apparent from the following Detailed Description, taken in connection with the accompanying drawings, in which: 
           [0012]      FIG. 1  is a diagrammatic illustration of a sequential manufacturing line for manufacturing an antenna; 
           [0013]      FIG. 2A  is a top view showing a near field communication antenna biscuit of the present disclosure after a first stamping; 
           [0014]      FIG. 2B  is a top view showing an example of a single near field communication antenna of the present disclosure stamped for a first time; 
           [0015]      FIG. 3A  is a top view of a pressure sensitive adhesive pad of the present disclosure; 
           [0016]      FIG. 3B  is a perspective view of the pressure sensitive adhesive pad of  FIG. 3A  with the release liner partially removed showing the pattern of adhesive; 
           [0017]      FIG. 3C  is a top view of the pressure sensitive adhesive pad of  FIG. 3A  with the release liner fully removed showing the pattern of adhesive; 
           [0018]      FIG. 4  is a perspective view of a fixture for receiving a pressure sensitive adhesive and first stamped antenna for further processing; 
           [0019]      FIG. 5  is a perspective view the pressure sensitive adhesive pad of  FIG. 3C  on the fixture of  FIG. 4 ; 
           [0020]      FIG. 6  is a perspective view the near field communication antenna biscuit of  FIGS. 2A-2B  on the fixture including the pressure sensitive adhesive of  FIG. 5 ; 
           [0021]      FIG. 7  is a top view the near field communication antenna biscuit of  FIGS. 2A-2B  and the pressure sensitive adhesive of  FIG. 5  on the fixture; 
           [0022]      FIG. 8  is a perspective view of the release liner being placed on the near field communication antenna biscuit that has been placed onto the fixture; 
           [0023]      FIG. 9  is a top view of the near field communication antennas and release liner after a second stamping; 
           [0024]      FIG. 10  is a perspective view of the near field communication antennas after a second stamping of  FIG. 9  with the release liner detached from the antennas; 
           [0025]      FIG. 11  is a top view of a single near field communication antenna of the present disclosure after a second stamping; 
           [0026]      FIG. 12  is a top view of a ferrite shield assembly sheet of the present disclosure; 
           [0027]      FIG. 13  is a perspective view of a near field communication antenna biscuit on a fixture prior to application of a ferrite layer; 
           [0028]      FIG. 14  is a perspective view of the near field communication antenna biscuit of  FIG. 13  with the ferrite shield assembly sheet of  FIG. 12  being placed thereon; 
           [0029]      FIG. 15  is a top view of the near field communication antenna biscuit with a ferrite layer applied; 
           [0030]      FIG. 16  is a top view of an individual near field communication antennas with a ferrite layer applied; 
           [0031]      FIG. 17  is a bottom view of an individual near field communication antennas with a ferrite layer applied; 
           [0032]      FIG. 18  is a top view of a pallet that can be used for manufacturing a stamped antenna; 
           [0033]      FIG. 19  is a perspective view of the pallet of  FIG. 18 ; 
           [0034]      FIG. 20  is a perspective view of the near field communication antenna biscuit of  FIG. 2  being placed onto the pallet of  FIG. 18 ; 
           [0035]      FIG. 21  is a top view of a ferrite shield assembly sheet placed on a first fixture or pallet; 
           [0036]      FIG. 22A  is a top view of the ferrite shields on the first fixture; 
           [0037]      FIG. 22B  is a top view of the plurality of antennas on a second fixture or pallet; 
           [0038]      FIG. 22C  is a top view of a plurality of adhesive cards; 
           [0039]      FIG. 23  is a top view of an adhesive card, an antenna, and a ferrite shield, showing the order that they are applied; 
           [0040]      FIG. 24  is an exploded view of a completed antenna including a ferrite shield; and 
           [0041]      FIG. 25  is a plan view of a sample manufacturing process for applying the ferrite shields. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]    The present invention relates to a method of manufacturing a stamped antenna. 
         [0043]      FIG. 1  is a diagrammatic illustration of a sequential manufacturing line for manufacturing a stamped antenna and provides a general overview of the manufacturing process. It should be understood by one of ordinary skill in the art that this manufacturing process can be employed in the manufacture of any antenna that includes thin traces, e.g., antennas used in radio frequency identification tags, inductive charging circuitry, etc. The antennas are manufactured at a plurality of stations that are arranged sequentially about the manufacturing line  10 . A supply reel  12  feeds an antenna material, e.g., a thin sheet of copper such as copper foil, to a first station  14  that includes a first precision high-speed stamping press for performing a first partial stamping of the antenna.  FIG. 2A  is a top view showing a group of near field communication antennas  16  after a first partial stamping by the first stamping press. After the first stamping, the antennas  18   a - e  include tie bars  20  and carriers  22  to add stability and support to the partially stamped antennas. After each group of antennas, the copper sheet is cut so that a near field communication antenna biscuit is created having a group of antennas, e.g., five as shown in  FIG. 2A . The biscuit  16  includes antennas  18   a - e  connected with carriers  22  and a series of tie bars  20  that extend between the antennas  18   a - 3  and within each respective antenna  18   a - e . Further, the tie bars  20  within each antenna  18   a - e , and between the antennas  18   a - e , support the antennas  18   a - e  and prevent the antennas  18   a - e  from being misshapen. The biscuit  16  also includes a plurality of pilot holes  24 , which will be discussed in greater detail. 
         [0044]      FIG. 2B  is a top view of an individual antenna  18   a  from the near field communication antenna biscuit  16  showing the individual antenna  18   a  in greater detail. As can be seen in  FIG. 2B , the antenna  18   a  includes an intricate shape of thin traces  26  connected to two paddles  28  or contacts. The traces  26  are interconnected by the series of tie bars  20  and connected to the carriers  22 . The series of tie bars  20  and carriers  22  provide stabilization, support, and strength for the thin traces  26  of the antenna  18   a  so that the traces  26  can be further processed without risk of breakage. At a second station  27 , the two contacts  28  could be gold plated. 
         [0045]    At a third station  29 , a pressure sensitive adhesive (PSA) pad  30  is placed onto a fixture  32  or jig.  FIG. 3A  is a top view of a PSA pad  30  including a release liner  34 .  FIG. 3B  is a perspective view of the PSA pad  30  of  FIG. 3A  with the release liner  34  partially removed.  FIG. 3C  is a perspective view of the PSA pad  30  with the release liner  34  completely removed. Removal of the release liner  34  exposes a plurality of adhesive areas  36 , having the general shape of the antennas. The PSA pad  30  includes a release liner  34 , adhesive areas  36 , and a plurality of die cut holes  38 . The PSA pad  30  of  FIGS. 3A-3C  includes five adhesive areas  36  to match the five antenna  18   a - e . The adhesive areas  36  are located and shaped to match the five antenna  18   a - e  such that the antenna traces  26  and contacts  28  are bonded with the adhesive areas  36 . The plurality of die cut holes  38  could be positioned along the perimeter of the PSA pad  30 . The die cut holes  38  match with any fixture pins  42  on the fixture  32  or jig, as well as the pilot holes  24  of the antenna biscuit  16 , and facilitate alignment of the PSA pad  30  on the fixture  32 , and alignment of the PSA pad  30  with the antenna biscuit  16 . 
         [0046]      FIG. 4  is a perspective view of a fixture  32  for receiving the PSA pad  30  and the antenna biscuit  16 . The fixture  32  includes a body  40  and a plurality of pins  42  for alignment of the PSA pad  30  and the antenna biscuit  16 . 
         [0047]      FIG. 5  is a perspective view of the PSA pad  30  on the fixture  32  of  FIG. 4 . The PSA pad  30  is placed over the fixture  32  so that the plurality of pins  42  are inserted into the die cut holes  38  of the PSA pad  30 . The release liner  34  of the PSA pad  30  is removed prior to placing the PSA pad  30  onto the fixture  32 . 
         [0048]    The antenna biscuit  16  is then transferred to the third station  29  to be aligned with the PSA pad  30  and the fixture  32 .  FIG. 6  is a perspective view of the group of antennas  16  of  FIG. 1  on the fixture  32  having a PSA pad  30  already placed thereon. The plurality of fixture pins  42  extend through the die cut holes  38  of the PSA pad  30  and facilitate alignment of the PSA pad  30  and the near field communication antenna biscuit  16 . The near field communication antenna biscuit  16  is placed onto the fixture  32  so that the fixture pins  42  extend through the pilot holes  24 .  FIG. 7  is a top view showing the near field communication antenna biscuit  16  and the PSA pad  30  on the fixture  32 . As can be seen, the traces  26  of each antenna  18   a - e  overlap an adhesive portion  36  of the PSA pad  30 . The previously removed release liner  34  is then placed on top of the near field communication antenna biscuit  16  as shown in  FIG. 8 . Placing the release liner  34  over the near field communication antenna biscuit  16  protects the PSA pad  30  during additional stamping processes. 
         [0049]    The fixture  32 , PSA pad  30  and antenna biscuit  16  are transferred to a fourth station  44  for bonding the antenna biscuit  16  with the PSA pad  30 . The fourth station  44  includes rollers that provide pressure for activating the PSA  30  and bonding the antenna biscuit  16  with the PSA pad  30 . Once bonded, the antenna biscuit  16 , now with a PSA layer  30 , is advanced to a fifth station  46  that includes a second precision high-speed stamping press for performing a second antenna stamping. The second stamping press performs a second stamping operation on the antenna biscuit  16  wherein the tie bars  20  are stamped and removed from each antenna  18   a - e . The second stamping press stamps through the foil that makes up the tie bars  20 , the PSA bonded to the tie bars  20 , and the release liner  34 . The carriers  22  will fall away upon stamping of the tie bars  20  because the carriers  22  are generally outside the adhesive area  36  of the PSA pads  30 . As such, the second stamping operation effectively removes each individual antenna  18   a - e  from the antenna biscuit  16  so that each antenna  18   a - e  is by itself, but supported by the PSA pad  30 .  FIG. 9  is a top view of the antenna biscuit  16 , PSA pad  30 , and release liner  34  after the secondary stamping. The antenna biscuit  16  and PSA pad  30  cannot be seen because they are covered by the release liner  34 . As can be seen, the plurality of tie bars  20  and carriers  22  have been stamped out and removed. The second stamping process can also stamp a plurality of guide holes  48  for future ferrite shield application, which will be discussed in greater detail. 
         [0050]    Once the second stamping is complete the release liner  34  can be peeled away, as shown in  FIG. 10 , which is a perspective view showing the release liner  34  removed from the antenna biscuit  16 . When the release liner  34  is removed, five individual and disconnected antennas  18   a - e  bonded to a single piece PSA pad  30  remain. In one embodiment, the PSA pad  30  may be cut so that each individual antenna  18   a - e  is separated from one another.  FIG. 11  is a top view of an individual antenna  18   a  after the second stamping and separated from the other individual antennas  18   b - e . The completed antenna  18   a  no longer includes a tie bar  20  connecting the traces  26  or the contacts  28 . The completed antennas  18   a - e  can then be sent to a sixth station  50  where they are packaged for distribution. 
         [0051]    In an alternative embodiment, the antenna biscuit  16  and PSA pad  30  of  FIG. 10 , e.g., without the release liner  34 , could be sent to an alternative sixth station  52  where instead of being cut into individual antennas, they are instead bonded with a ferrite shield.  FIG. 12  is a view of a ferrite shield  54  assembly sheet that may be used. The ferrite shield assembly sheet  54  includes a liner  56 , a series of ferrite shields  58 , and a plurality of pilot holes  60 . The ferrite shield assembly sheet  54  is generally sized, dimensioned, and arranged so that each individual ferrite shield  58  generally overlaps a respective antenna  18   a - e  of the antenna biscuit  16 . 
         [0052]      FIG. 13  is a perspective view of the antennas  18   a - e  and PSA pad  30  sub-assembly placed on a fixture, with the antennas  18   a - e  facing upward and the PSA pad  30  abutting the fixture  62 . The fixture  62  includes a body  64  and a plurality of guide pins  66  that are aligned with and inserted into the guide holes  48  the PSA pad  30 . As shown in the perspective view of  FIG. 14 , the ferrite shield assembly sheet  54  of  FIG. 12  is placed on to the fixture  62  such that the guide pins  66  of the fixture  62  are aligned with and inserted into the pilot holes  60  of the ferrite shield assembly sheet  54 . The ferrite shield assembly sheet  54  is oriented such that the series of ferrite shields  58  are facing the copper antennas  18   a - e . When the ferrite shield assembly sheet  54  is placed on the fixture  62 , the ferrite shields  58  overlap the antennas  18   a - e , such that there is one ferrite shield  58  for each individual antenna  18   a - e . The ferrite shields  58  are then bonded to the respective antenna  18   a - e  by means that are known in the art, for example, a vacuum adhesive. Once bonded, the ferrite shield liner  56  can be removed, leaving a series of five individual antenna  18   a - e  each having a ferrite shield  58  bonded thereto, as shown in  FIG. 15 . The antennas  18   a - e , held together as a group by the PSA pad  30 , can be cut into individual antenna  18   a - e  and the PSA pad  30  can be removed.  FIGS. 16-17  show an antenna  18   a  having a ferrite shield  58 . 
         [0053]      FIGS. 18-20  show an alternative embodiment in which a pallet  70  is used in place of the fixture  32 . The pallet  70  includes a body  72 , a handle  74  extending from the body  72 , a plurality of pilot holes  76 , a plurality of guide pins  78 , and a plurality of removed sections  80 . The plurality of pilot holes  76  are positioned to match guide pins of a stamping machine so that the pallet  70  is properly aligned when engaged with the machine. The plurality of guide pins  78  facilitate positioning a PSA pad  30 , antenna biscuit  16 , and ferrite shield assembly sheet  54  during manufacturing. The guide pins  78  ensure that the PSA pad  30  and antenna biscuit  16  are located such that the tie bars  20 , carriers  22 , and portions that need to be cut by pressing are positioned over the removed sections  80 . The removed sections  80  allow a die to be pressed through the PSA pad  30  and the antenna biscuit  16 , thus facilitating removal of the tie bars  20  and carriers  22 . 
         [0054]      FIGS. 21-25  shown another method for applying a ferrite shield layer.  FIG. 21  is a top view of a ferrite shield assembly sheet  82  placed on a first fixture or pallet  84 . The ferrite shield assembly  82  includes a liner  86  and a plurality of ferrite shields  88 . The ferrite shield assembly  82  is placed on the first fixture  84  such that the ferrite shields  88  are face down on the first fixture  84 , e.g., adjacent the first fixture  84 , and the liner  86  is face up. The first fixture  84  can include a vacuum or magnets that hold the ferrite shields  88  in place. Accordingly, the liner  86  can be removed from the ferrite shields  88 , and the ferrite shields  88  will be retained in place by the fixture  84 . 
         [0055]      FIG. 22A  is a top view of the ferrite shields  88  on the first fixture  84 .  FIG. 22B  is a top view of the plurality of antennas  18   a - e  on a second fixture or pallet  90 .  FIG. 22C  is a top view of a plurality of adhesive cards  92 . Each of the plurality of adhesive cards  92  includes a bottom release liner (not shown), a top liner  94 , an adhesive area  96 , an two alignment holes  98 . The bottom release liner is a continuous liner that spans one or more of the adhesive cards such as the five adhesive cards  92  shown, and is removed during assembly to expose the adhesive areas  96 . The top liner  94  is cut into a square/rectangle that extends beyond the edges of the adhesive area  96 . The two alignment holes  98  facilitate alignment of the adhesive cards  92  with a pick-up pad. 
         [0056]      FIG. 23  is a top view of an adhesive card  92 , an antenna  18   a , and a ferrite shield  88 , showing the order that they are assembled. As shown in  FIG. 23 , the adhesive card  92  is first applied to the antenna  18   a , and then the ferrite shield  88  is applied over the antenna  18   a  and onto the adhesive card  92 . This application process is discussed in greater detail in connection with  FIG. 25 .  FIG. 24  is an exploded side view of a completed antenna  100  including a ferrite shield  88 . The completed antenna  100  includes a plurality of layers that include, from top to bottom, the top liner  94 , the adhesive area  96 , the antenna  18   a , and the ferrite shield  88 . 
         [0057]      FIG. 25  is a plan view of a sample manufacturing process for applying the ferrite shield  88 . Once the PSA  30  is bonded with an the antenna biscuit at the fourth station  44  of  FIG. 1 , the antenna biscuit with PSA layer  30  can be transferred to a loading station  102 , where it is loaded onto a conveyor belt or track  104 . The antenna biscuit is transferred to a second or complete stamping station  106  where the tie-bars are removed and the antennas are singulated by a second stamping process, which is in accordance with the fifth station  46  of  FIG. 1 , described above. The individual antennas are delivered by the conveyor  104  to a pallet loading station  108  where the antennas are placed on a pallet or plate. The pallet could be configured like the pallet  70  shown in  FIGS. 18-20 . The pallet can hold any number of antennas, such as five antennas, for example. The pallet with antennas is then conveyed to an assembly station  110 . 
         [0058]    The assembly station  110  could include a robotic device  112 , which could have 3-axis movement, an adhesive applicator  114 , and a robotic cylinder  116 . The assembly station  110  receives the antennas and attaches the ferrite shields  88 . In preparation for applying the ferrite shields  88  to the antennas, the adhesive applicator  114  removes the bottom liner of the adhesive cards  92 , rolls the removed bottom liner onto a scrap roller, and places each adhesive card  92  into a tray of the robotic cylinder  116 . The robotic cylinder  116  transfers the adhesive cards  92  to the robotic device  112 . The robot device  112  could be a robotic pick-up pad that could be a vacuum pad attached to the end of an arm of the robotic device  112  to pick up the adhesive cards  92 . The robotic device  112  includes pilot pins that engage the alignment holes  98  of the adhesive cards  92  and locate/align the adhesive cards  92 . Once the adhesive cards  92  are ready for transferring, the robotic device  112  moves the adhesive cards  92  into alignment over the antennas, which are transferred by the pallet  70 . The robot  112  then stamps the adhesive cards  92  onto the antennas, such that the adhesive areas  96  engage the antennas, and picks the antennas up. Next, the robotic device  112  moves the adhesive card  92  and antenna sub-assembly over the first fixture  84  containing the ferrite shields  88 , and stamps down on the ferrite shields  88  to bond the ferrite shields  88  to the antennas and the adhesive cards  92 . The antennas, including adhesive cards  92  and ferrite shields  88 , are then transferred along the conveyor belt to a pick-and-pack station  118  where the antennas are removed from the conveyor  104 , scrap is removed, and the antennas are packaged. 
         [0059]    Having thus described the invention in detail, it is to be understood that the foregoing description is not intended to limit the spirit or scope thereof. What is desired to be protected is set forth in the following claims.