Patent Application
20220230038
The present subject matter relates to radio frequency identification (“RFID”) devices. More particularly, the present subject matter relates to self-adhesive RFID straps and techniques for mounting such RFID straps to antennas.
RFID tags and labels (collectively referred to herein as “devices”) are widely used to associate an object with an identification code. RFID devices generally have a combination of antennas and analog and/or digital electronics, which may include, for example, communications electronics, data memory, and control logic. For example, RFID tags are used in conjunction with security locks in cars, for access control to buildings, and for tracking inventory and parcels.
One difficulty associated with manufacturing RFID devices is the need to assemble them in dedicated RFID device manufacturing facilities. This is due, in part, to the manner in which the antenna of such a device is secured to the other components of the device. For example, in one approach, an antenna and a separate RFID strap (which includes an RFID chip) are provided. An adhesive is applied to pads of the antenna, followed by the RFID strap being placed into contact with the adhesive. The adhesive is then cured to secure the RFID strap to the antenna. The properties of the adhesive are critical to the function and parameters of the RFID device (e.g., the minimum power at which the device can respond to a reader system and the frequency at which the device is configured to optimally operate), which requires advanced manufacturing facilities to achieve the required control. As such, RFID devices of this type may only be manufactured and assembled at specialized facilities.
For convenience, an RFID manufacturing factory or facility may be positioned in the vicinity of a factory or facility of a product manufacturer that acquires the RFID devices from the RFID manufacturing facility for incorporation into its products. So locating the two factories reduces the costs for shipping the RFID devices from the RFID manufacturer to the product manufacturer. However, if the product manufacturer move its factory or facility to another location (e.g., to a different country, due to manufacturing cost considerations), the costs of shipping the RFID devices from the factory or facility of the RFID manufacturer to the new location could be significantly increased, along with an increased environmental impact.
Additionally, an RFID manufacturer may prefer to create RFID devices in a large quantity, due to economies of scale. As a result, the number of RFID devices preferred to be made by the RFID manufacturer may be greater than the number required by a customer.
Therefore, there exists a need for an RFID device that may be assembled at a factory or facility other than a dedicated RFID device manufacturing factory or facility. There also exists a need for an RFID device that may be more simply assembled, allowing for (preferably portable) “build on demand” systems capable of producing a smaller number of RFID devices than are typically produced using conventional approaches.
Accordingly, it is an object of the present disclosure to provide an RFID device that may be assembled at a factory or facility other than a dedicated RFID device manufacturing factory or facility. It is also an object of the present disclosure to provide an RFID device that may be more simply assembled, allowing for (preferably portable) “build on demand” systems capable of producing a smaller number of RFID devices than are typically produced using conventional approaches.
There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as may be set forth in the claims appended hereto.
RFID devices including an antenna defining a gap and an RFID strap electrically coupled to the antenna across the gap, and methods of making and using thereof, are described herein.
In some embodiments, the RFID strap is secured to the antenna by a self-adhesive substance or material. In some embodiments, the self-adhesive substance or material contains, or is, a pressure-sensitive adhesive, an isotropic conductive adhesive, such as a paste or film, or an anisotropic conductive adhesive, such as a paste or film.
Methods of assembling an RFID device are also described. In some embodiments, the method includes providing an antenna and an RFID strap. The method further includes securing the RFID strap to the antenna using a self-adhesive substance, as described above, so as to electrically couple the RFID strap to the antenna across a gap defined by the antenna.
Systems for assembling the RFID devices are described herein. In some embodiments, the system for assembling an RFID device includes an antenna creation station configured to form an antenna defining a gap. In some embodiments, the system includes an antenna creation station as described above and a strap attach station configured to electrically couple an RFID strap to the antenna across the gap, with the RFID strap being secured to the antenna by a self-adhesive substance or material as described above. In some embodiments, the system includes the creation attachments stations described above and further includes a testing station configured to test the performance of an RFID device assembled by the system. In still other embodiments, the system contains the creation, attachment, and testing stations as described above, and further includes a programming station configured to program an RFID chip of an RFID device assembled by the system. The systems described above can further include a printing station configured to apply human-readable indicia to an RFID device assembled by the system and/or a cutting station configured to cut a portion of an RFID device assembled by the system. The various stations described above can be located at one location, e.g., within one facility, or at multiple locations or within multiple facilities at the same locations.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate manner.
Rather than an adhesive being applied to the pads 12 and 14 (as in a conventional approach), a self-adhesive substance or material 18 having defined characteristics (e.g., thickness and the real and imaginary part of the dielectric constant) is applied to an RFID strap 20 (
The nature of the self-adhesive substance 18 may vary without departing from the scope of the present disclosure. For example, in one embodiment, the self-adhesive substance 18 is or contains a pressure-sensitive adhesive 18a, as in
Depending on the nature of the self-adhesive substance or material 18, the RFID strap 20 may be coupled to the antenna 10 by reactance, for example E-field coupling, inductive H-field coupling, or a combination of both. The coupling is a function of the properties of the self-adhesive substance or material 18, such as capacitance being affected by the thickness of the self-adhesive substance or material 18 (i.e., with a doubled thickness resulting in capacitance being reduced by a factor of two). The coupling is also related to the real and imaginary part of the dielectric constant, with a doubling of the real part of the dielectric constant increasing capacitance by a factor of two. The impact of the imaginary part is more complex, however, as an increase is associated with higher loss of RF energy flowing through the material between the antenna pads 12 and 14 and pads of the RFID strap 20 (via the self-adhesive substance or material 18). Accordingly, care should be taken when selecting and applying the self-adhesive substance or material 18 to ensure that it allows for the desired, typically an optimal, performance of the resulting RFID device 22.
The use a self-adhesive substance or material 18 to join the antenna 10 and the RFID strap 20 may have a number advantages. For example, compared to conventional approaches, the assembly process illustrated in
In addition to the transfer of the components of the RFID device 22 (principally, the RFID strap 20) from the manufacturer to the assembly location, intellectual property, such as antenna designs and attachment methods, may also be transferred to allow for on-site assembly of simplified RFID devices 22. It may be beneficial, for example, for the assembly location to be provided with the tools and know-how required to print conductive ink or to fashion a foil into an antenna (e.g., by punching or cutting the foil), rather than providing the assembly location with finished antennas (although it is also within the scope of the present disclosure for the manufacturer to provide the assembler with formed or finished antennas). In another example, an assembler may be provided with the tools and know-how required to test assembled RFID devices.
The reduction of machine complexity made possible by the RFID devices described herein may also allow for the use of small (e.g., small foot print), possibly mobile “build on demand” systems that can assemble the RFID devices described herein e.g., 22. One or more of such systems may be installed in the facility or factory of the assembler or local to such a facility. Depending on the location in which such a system is installed, it may be provided with a support system, which may include power and data communications, such as a satellite transceiver, if access to such capabilities is not available or reliable in that location. By assembling the RFID devices on-site, there are fewer disadvantages attendant to relocation of the facility or factory of the assembler farther from the factory or facility of an RFID device manufacturer (including increased shipping costs and environmental externalities).
An exemplary “build on demand” system 24 is shown in
Additional stations of the system 24 could include a strap attach station 28 configured to electrically couple an RFID strap 20 to an antenna 10 by a self-adhesive substance 18, as described above. A testing station 30 positioned downstream of the strap attach station 28, if provided, may be configured to test the performance of an RFID device 22 assembled by the system 24. A programming station 32, if provided, may be configured to program the RFID chip 34 of an RFID device 22 assembled by the system 24. A printing station 36, if provided, may be configured to apply human-readable indicia to an RFID device 22 assembled by the system 24. A cutting station (identified at 38), if provided, may be configured to cut a portion of an RFID device 22 assembled by the system 24, using an X-Y cutter or a laser, for example. An RFID device 22 assembled by the system 24 may be incorporated into a piece of merchandise or the like (e.g., a product tag) after exiting the system 24, as identified at 40. It should be understood that a “build on demand” system according to the present disclosure may be provided with fewer than all of the stations illustrated in
The size and portability of “build on demand” systems may vary, depending on their configuration and functionality. For example, it is contemplated that such a system may be configured to fit inside of a standard shipping container for travel by land and/or sea. In another embodiment, such a system may be configured for easy air freight to assist in rapid movement from one location to another. In yet another embodiment, a “build on demand” system may be provided as a “desktop” unit, being similarly sized to printers already used as part of RFID provision to a product manufacturer for printing variable human readable information.
The present invention contemplates that an RFID manufacturer may prefer to create RFID devices in a large quantity, due to economies of scale. The number of RFID devices preferred to be made by the RFID manufacturer may be greater than the number required by a customer. In one embodiment presently contemplated by the present invention a wet strap construction for an inlay may be created. The present invention contemplates that the adhesive used in correlation with the strap is a pressure sensitive adhesive, but is not limited to such. There are several ways that a wet strap may be constructed. For instance, in one embodiment, in a traditional wet strap construction process, the strap is made using a lead frame, chip adhesive and at least one chip in a chip attach machine. The strap may then be converted into a wet strap by using either 1) a laminating transfer tape and/or 2) applying at least one adhesive with a liner before cutting into individual straps, such as pressure sensitive straps, on a reel.
In another embodiment, presently contemplated for constructing wet straps, the lead frame is first converted in order to first make a wet lead frame. The wet lead frame may be run through a chip attach machine to apply at least one chip adhesive and attach at least one chip to make the finished inlay. This wet first strap method allows for the chip, which has a higher cost compared to the rest of the inlay, to be attached at the end of the manufacturing process thus reducing the risk of damage to the chip and reducing the overall cost of the strap. It is important to note that for both the methods of wet inlay construction briefly mentioned herein, the lead frame can be made either via 1) a traditional etched process, 2) hybrid process which includes at least two cutting steps, one of which may be with a laser and/or 3) with a laser. It is contemplated that the lead frame can be made solely by one of these methods or a combination of the methods mentioned herein.
In another embodiment presently contemplated for wet strap construction, a wet hybrid lead frame process is utilized. This process is similar to a wet first strap method but the lead frames may be flood coating or an adhesive maybe printed on a liner. A conductor laminate, aluminum on PET or paper, may then be laminated, and a bond area (chip gap) is cut. The cutting may be done by a laser, mechanical die cut, or any other way of cutting known in the art. Next, a cross web is cut and the web is slit down to create individual lead frames in a reel. These lead frames may then go, in one embodiment, through a chip attach process. This wet hybrid lead frame process allows for a faster and simpler manufacturing process and a lower tooling and material cost.
It will be understood that the embodiments described above are illustrative of some of the applications of the principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that claims may be directed to the features hereof, including as combinations of features that are individually disclosed or claimed herein.
The present application claims priority to and the benefit of United States provisional utility patent application No. 62/836,900 filed Apr. 22, 2019, which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/029284 | 4/22/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62836900 | Apr 2019 | US |
