The present invention relates generally to the field of wireless communication. In particular, the present invention relates to antennas and methods for forming antennas for use in wireless communications.
With the proliferation of wireless products and services, device manufacturers are forced to aggressively pursue cost reduction opportunities in the manufacturing and assembly of wireless device components. Reduction of costs associated with wireless antennas may thus be an important factor in staying competitive. Implementation of a cost-effective antenna may become even more critical as new features and functionalities are added to wireless devices that require more sophisticated antennas.
An internal antenna for a wireless device is typically manufactured as either a stamped metal element or as a flex-circuit antenna on a plastic carrier. Both technique suffer from high cost of production. The stamped metal element and the plastic carrier both require expensive and time consuming tooling for high volume production. Furthermore, while the flex-circuit antenna may be readily fabricated using a standard etching process, this technique is typically a more expensive solution compared to a stamped metal element.
It is the goal of the various embodiments of the present invention to provide methods of forming cost effective and reliable wireless antennas in one aspect of the invention, a method for forming an antenna comprises providing a non-conductive carrier sheet, applying a conductive layer to at least a portion of the carrier sheet, and forming one or more antennas by thermoforming the carrier sheet and the conductive layer. In one embodiment, the conductive layer is applied to one side of the carrier sheet, while in another embodiment the conductive layer is applied to both sides of the carrier sheet.
In another embodiment, the applying of the conductive layer comprises at least one of a printing, attaching, and deposition of the conductive layer in one embodiment, the printing is conducted in accordance with a stencil printer. According to another embodiment, the carrier sheet comprises a plastic sheet. In yet another embodiment, the forming produces a plurality of three-dimensional antennas that are separated into individual antenna structures with a cutting apparatus.
in another embodiment, the plurality of antennas are situated in a two dimensional array and, in another embodiment, the forming produces one or more two-dimensional antenna patterns. The antenna patterns may comprise one or more folding lines for shaping the patterns into one or more three-dimensional antenna structures. In one embodiment, one or more of the folding lines is produced using a laser cutter.
In yet another embodiment, the forming produces one or more antennas on a tape portion of a tape-on-reel package. In another embodiment, the forming further produces one or more protrusions for connecting at least one of a ground and an electrical feed associated with the antennas to a circuit board. The one or more protrusions fit into one or more depressions on the circuit board. In another embodiment, the forming further produces one or more contact bumps for connecting at least one of a ground and an electrical feed associated with the antennas to a circuit board.
In another embodiment, the one or more antennas further comprise one or more metal clips for connecting at least one of a ground and an electrical feed associated with the antennas to a circuit board. In one embodiment, the connecting is effected in accordance with one or more through holes on the circuit board while in another embodiment, the connecting is effected in accordance with one or more pads on the circuit board. In another embodiment, one or more metal springs are used for connecting at least one of a ground and an electrical feed associated with the antennas to a circuit board. In another embodiment, the thermoforming comprises vacuum forming. In yet another embodiment, the applying is carried out after thermoforming the carrier sheet.
Another aspect of the present invention relates to an antenna comprising a non-conductive portion, a conductive portion positioned on at least a portion of the non-conductive portion, and one or more protrusions in at least the conductive portion for connecting at least one of a ground and an electrical feed associated with the antenna to a circuit board. The antenna may be formed by applying a conductive layer to a non-conductive carrier sheet and thermoforming the carrier sheet and conductive layer. The antenna may also be formed by thermoforming a non-conductive carrier sheet and applying a conductive layer to the thermoformed carrier sheet.
Those skilled in the art will appreciate that various embodiments discussed above, or parts thereof, may be combined in a variety of ways to create further embodiments that are encompassed by the present invention.
a) illustrates a tape strip corresponding to a tape-and-reel system;
b) illustrates a plurality of antennas in accordance with an exemplary embodiment of the present invention;
In the following description, for purposes of explanation and not limitation, details and descriptions are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these details and descriptions.
The antennas and methods described in accordance with embodiments of the present invention reduce the number of components in a wireless antenna to a as few as a single component, and thus significantly reduce the complexity and costs associated with antenna fabrication. Embodiments of the invention achieve this goal by manufacturing cost-effective antenna structures using a thermoforming process. Thermoforming may refer to the process of forming a thermoplastic sheet into a three-dimensional shape by clamping the sheet in a frame, heating it to render it soft and pliable, then applying differential pressure to make the sheet conform to the shape of a mold or die positioned below the frame. When the pressure is applied entirely by vacuum, the process is called ‘vacuum forming.’
In accordance with the various embodiments of the present invention, prior to vacuum forming, a conductive antenna pattern may be printed, deposited, or placed (hereinafter, collectively referred to as ‘applied’) on a plastic sheet or other nonconductive carrier material. The conductive antenna pattern may be applied to one or both sides of the plastic carrier. In some applications, however, it may be advantageous to use the plastic sheet as a protective layer by applying the antenna pattern to the bottom of the plastic carrier. This configuration, which may also provide an enhanced cosmetic appearance, can be used to implement an integrated contact point between the antenna terminals and the circuit board of the wireless device. Once the conductive material is applied to the plastic carrier, the vacuum forming process, or other processes for providing a pressure differentiated forming, creates one or more low cost antennas with an integrated plastic carrier. A laser or other cutting mechanism may be used to subsequently cut out individual finished antenna structures that are now ready to be integrated into various communication devices.
The conductive pattern may be applied using a variety of techniques, including, but not limited to, printing conductive (e.g., silver) inks, placing or attaching copper or aluminum sheets, or depositing copper or other conductive materials on the plastic sheet using electro-deposition or similar techniques. The conductive material may be any one of silver, copper, aluminum, gold, or other conductive elements or composites. In one embodiment, the antenna pattern may be cut, punched, or etched onto the conductive material prior to it application to the plastic sheet. It should also be noted that the choice of non-conductive material is not limited to plastic, and it may comprise any material that can be formed by the thermoforming process.
Referring again to
In another embodiment of the present invention, tape-and-reel packaging techniques may be adapted to enable manufacturing of low cost integrated antennas. Tape-and-reel packaging comprises a carrier ‘tape’ with formed cavities for holding the SMD (surface mount device) components.
In accordance with another embodiment of the present invention, the conductive material may be applied to one or both sides of a carrier to form a two-dimensional sheet with a plurality of antenna patterns. The two-dimensional antenna patterns may further be folded along predetermined locations to form the final three-dimensional antenna structures. This process may be facilitated by using a cutting apparatus, such as a laser cutter, to create ‘folding’ lines on the two-dimensional antenna sheets. Alternatively, or additionally, the thermoforming process can be used to form the folding lines. The individual two-dimensional antenna structures may then be folded along these lines at any time prior to the integration of the antennas into the communication devices.
a-b illustrate another antenna in accordance with an exemplary embodiment of the present invention. Antenna 70 is placed (or attached) to a printed circuit board (PCB) 71 or another intended device.
In accordance with another embodiment of the present invention, integrated contact bumps are implemented for providing electrical connection between the feed and/or ground point of the thermoformed antenna and the circuit board of the communication system.
In accordance with another embodiment of the present invention, metalclips are used to provide a connection between the antenna feed and/or ground locations of the thermoformed antenna and the circuit board.
In accordance with another embodiment of the present invention, electrical contact between the feed and/or ground locations of an antenna with a circuit board may be effected using a contact spring.
While particular embodiments of the present invention have been disclosed, it is to be understood that various modifications and combinations are possible and are contemplated within the true spirit and scope of the appended claims. There is no intention, therefore, of limitations to the exact abstract and disclosure herein presented.
This application claims benefit of priority of U.S. Provisional Application Ser. No. 61/037,278 titled “Methods for Forming Antennas Using Thermoforming” filed Mar. 17, 2008, the contents of which are hereby incorporated by reference.
Number | Date | Country | |
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61037278 | Mar 2008 | US |