Dual-mode radio frequency identification device

Abstract

The dual-mode radio frequency identification (RFID) device is provided with an integrated dual-mode radio frequency identification connecting band, and the integrated dual-mode radio frequency identification connecting band comprises an ultrahigh frequency / high frequency (UHF / HF) dual-mode radio frequency identification chip or a combination of an ultrahigh frequency radio frequency identification chip and a high frequency radio frequency identification chip. A high frequency (HF) antenna and an ultrahigh frequency (UHF) antenna are both coupled to the integrated dual-mode radio frequency identification connection band, the ultrahigh frequency antenna is formed by methods other than etching, such as cutting or printing operations, thereby reducing the cost of manufacturing the device. If a pair of chips is employed, one of the pair of chips may have a greater thickness than the other, which enables the thicker chip to be integrated into the device after the thinner chip without the need for a minimum spacing between the two chips that is set due to the size of the hot electrode used to fix the chips. Further, the first chip may be tested prior to securing the second chip, thereby limiting the cost of abandoned devices.

Description

[0001] This is a divisional application of case with application number 2020800962912, application date 2020-12-28, and title Dual-mode radio frequency identification device.

[0002] Cross-reference to Related Applications

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 954,455, filed December 28, 2019, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0004] The present invention relates to dual-mode radio frequency identification (“RFID”) devices. More particularly, the present invention relates to a low-cost method of manufacturing dual-mode radio frequency identification devices. BACKGROUND

[0005] Radio frequency identification devices contain an integrated circuit (or chip) and an antenna, and are widely used to associate objects with a unique identification code. The antenna transmits and receives signals that are transmitted at a particular frequency or within a particular frequency band. For example, a radio frequency identification device can be configured to transmit and receive signals within a high frequency (“HF”) band (i.e., signals having a frequency in the range of about 3 MHz to 30 MHz) or within an ultra-high frequency (“UHF”) band (i.e., signals having a frequency in the range of about 300 MHz to 3000 MHz). More particularly, high frequency radio frequency identification devices tend to operate at a frequency of about 13.56 MHz, while ultra-high frequency radio frequency identification devices tend to operate at a frequency in the range of about 866 MHz to 915 MHz (or 902 MHz to 928 MHz in North America).

[0006] In many applications, it is desirable to employ a radio frequency identification device that operates in multiple frequency bands, such as HF and UHF. U.S. Patent No. 9,871,294, which is hereby incorporated by reference, describes an example dual-frequency radio frequency identification device. Dual-frequency radio frequency identification devices can be variously configured, such as employing a dual-mode radio frequency identification chip that is electrically coupled to a pair of antennas that are configured to transmit and receive signals of different frequency bands according to a method. Alternatively, dual-frequency radio frequency identification devices include a first chip / antenna pair and a second chip / antenna pair, the first and second pairs operating at different frequency bands.

[0007] High frequency antennas are often made using etching processes due to their small geometry and the need for connections (bridges) between the inside and outside of the coil or interconnections (crimps) to a second coil antenna on the other side of the substrate via the substrate. For similar reasons, ultra high frequency straps (containing a pair of conductive pads configured to electrically couple to an ultra high frequency antenna and a radio frequency identification chip) are also often etched. However, while etching techniques have proven effective in creating radio frequency identification devices, they can be expensive compared to other methods. SUMMARY

[0008] The present invention has several aspects, which can be embodied alone or together in the devices and systems described and claimed below. These aspects can be employed individually or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude separate use of these aspects, or separate or different combinations of these aspects, as can be listed in the claims of the invention.

[0009] Described herein are dual-mode radio frequency identification devices containing an integrated radio frequency identification strap with dual-mode capability. In some embodiments, the integrated dual-mode radio frequency identification strap is configured as a reactive strap and contains a high frequency antenna and a conductive loop coupled to a radio frequency identification chip assembly. In some embodiments, the integrated dual-mode radio frequency identification strap is configured to couple with an ultra high frequency antenna without physical contact between the integrated dual-mode radio frequency identification strap and the ultra high frequency antenna.

[0010] In some embodiments, the integrated dual-mode radio frequency identification strap, containing the high frequency antenna and the conductive loop coupled to a radio frequency identification chip assembly described above, is on a single substrate.

[0011] In some embodiments, the integrated dual-mode radio frequency identification strap is configured as a reactive strap described above, magnetically coupled, conductively coupled, and / or capacitively coupled to the ultra high frequency antenna.

[0012] In some embodiments, the radio frequency identification chip assembly of the integrated dual-mode radio frequency identification strap contains a radio frequency identification coupling strap and a dual-mode radio frequency identification chip. In one embodiment, the dual-mode radio frequency identification chip contains an ultra high frequency / high frequency dual-mode radio frequency identification chip. In another embodiment, the dual-mode radio frequency identification chip contains a combination of an ultra high frequency radio frequency identification chip and a high frequency radio frequency identification chip, with each chip separately disposed on the radio frequency identification coupling strap.

[0013] In some embodiments, the integrated dual-mode RFID connection strap includes a conductive loop and a high frequency antenna attached to the RFID coupling connection strap by an adhesive material, such as a pressure sensitive adhesive.

[0014] Methods for manufacturing dual-mode RFID devices are also described herein. In some embodiments, the method includes providing an integrated dual-mode RFID connection strap having an RFID chip assembly including an ultra-high frequency / high frequency dual-mode RFID chip, or a combination of an ultra-high frequency RFID chip and a high frequency RFID chip. In some embodiments, the integrated dual-mode RFID connection strap further includes a conductive loop and a high frequency antenna attached, affixed, or coupled to the RFID chip assembly. In some embodiments, the high frequency antenna and the conductive loop are coupled to the RFID chip assembly at opposite ends thereof. In one embodiment, the conductive loop is an ultra-high frequency (UHF) loop. In some embodiments, the presence of the conductive loop as part of the integrated dual-mode RFID connection strap enables the connection strap to be coupled with the ultra-high frequency antenna. In some embodiments, the ultra-high frequency antenna is formed without etching.

[0015] In some embodiments, the method for manufacturing a dual-mode RFID device including an RFID chip assembly involves using a thermode to secure a first RFID chip to a structure of the dual-mode RFID device to apply heat and pressure between the first RFID chip and the structure. In some embodiments, a second RFID chip is then secured to the structure using the thermode with at least a portion of the first RFID chip positioned between the thermode and the structure.

[0016] In some embodiments, the method for manufacturing a dual-mode RFID device including an RFID chip assembly involves securing a first RFID chip to a structure of the dual-mode RFID device, and then subjecting the first RFID chip to a first test. If the first RFID chip fails the first test, the dual-mode RFID device is rejected. If the first RFID chip passes the first test, a second RFID chip is secured to the structure, and then the second RFID chip is subjected to a second test. If the second RFID chip fails the second test, the dual-mode RFID device is rejected; if the second RFID chip passes the second test, the dual-mode RFID device is accepted. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of an exemplary dual-mode RFID device according to an aspect of the present application.

[0018] Figure 2 yes Figure 1 A schematic diagram of a first exemplary embodiment of the RFID connection band of a dual-mode RFID device, which employs an ultra-high frequency / high frequency dual-mode RFID chip.

[0019] Figure 3 yes Figure 1 A schematic diagram of a second exemplary embodiment of the RFID connection band of a dual-mode RFID device, which employs a combination of an ultra-high frequency RFID chip and a high frequency RFID chip.

[0020] Figure 4 This is a schematic diagram of another embodiment of an exemplary dual-mode radio frequency identification device according to one aspect of the present invention.

[0021] Figure 5 yes Figure 4 A detailed view of a portion of an alternative embodiment of a dual-mode RFID device, wherein a portion of the high-frequency antenna of the dual-mode RFID device defines a portion of the conductive ring of the dual-mode RFID device.

[0022] Figure 6 This is a schematic diagram of an exemplary embodiment of a pair of radio frequency identification (RFID) chips that can be integrated into a dual-mode RFID device according to one aspect of the present invention. Detailed Implementation

[0023] The embodiments disclosed herein are merely exemplary, and the subject matter described herein can be embodied in various forms. Therefore, the specific details disclosed herein should not be construed as limiting the invention as defined in the claims.

[0024] Figure 1 A dual-mode RFID device 10 (e.g., an RFID tag or label) according to one aspect of the present invention is illustrated. The dual-mode RFID device 10 includes an integrated dual-mode RFID connection strip 11 configured to couple to an ultra-high frequency (UHF) antenna 16. The integrated dual-mode RFID connection strip 11 includes a high-frequency antenna 14 coupled to an RFID chip assembly 12 and a conductive ring 13. In some embodiments, the integrated dual-mode RFID connection strip 11 enables coupling between the high-frequency antenna 14 and the UHF antenna 16 via the conductive ring 13. In this embodiment, the conductive ring 13 is an ultra-high frequency (UHF) ring coupled to the RFID chip assembly 12. However, other conductive structures may also be used.

[0025] Figure 2A radio frequency identification chip assembly 12 is shown that includes a radio frequency identification coupling strap 15, a conductive pad 30, and one or more radio frequency identification chips. The radio frequency identification chip assembly 12 is coupled on one side to a high frequency antenna 14 and on the other side to a conductive loop 13. In particular, the high frequency antenna 14 and the conductive loop 13 are attached to the radio frequency identification coupling strap 15. In one embodiment, the high frequency antenna 14 and the conductive loop 13 are coupled, affixed, or attached to the radio frequency identification coupling strap 15 using an adhesive material, such as a pressure sensitive adhesive. The high frequency antenna 14, the conductive loop 13, and the radio frequency identification chip assembly 12 that couples both the high frequency antenna 14 and the conductive loop 13 are integrated in a common substrate, while the integrated dual-mode radio frequency identification strap 11, which functions as a "combo strap," is separate from the ultra-high frequency antenna 16.

[0026] The one or more radio frequency identification chips of the radio frequency identification chip assembly 12 include a single ultra-high frequency / high frequency dual-mode radio frequency identification chip 18 Figure 2 , or a combination of an ultra-high frequency radio frequency identification chip 20 and a high frequency radio frequency identification chip 22 Figure 3 . Many aspects of the present application can be used with a radio frequency identification coupling strap 15 having one or two radio frequency identification chips. However, certain aspects of the present application are particularly suited for use with a radio frequency identification coupling strap 15 having a pair of radio frequency identification chips 20 and 22, as will be described in greater detail herein.

[0027] Regardless of the particular configuration of the radio frequency identification chip assembly 12, the integrated dual-mode radio frequency identification strap 11 is configured for coupling to both the high frequency antenna 14 and the ultra-high frequency antenna 16. Figure 2 and Figure 3 A radio frequency identification coupling strap 15 is shown having a pair of high frequency connections 24 (associated with an ultra-high frequency / high frequency dual-mode radio frequency identification chip 18 Figure 2 ) or a high frequency radio frequency identification chip 22 Figure 3 ) and a pair of ultra-high frequency connections 26 (associated with an ultra-high frequency / high frequency dual-mode radio frequency identification chip 18 Figure 2 ) or an ultra-high frequency radio frequency identification chip 20 Figure 3 ).

[0028] The nature and configuration of the high frequency connections 24 and the ultra-high frequency connections 26 can vary depending on the nature and configuration of the associated antennas. In Figure 1 an embodiment, the high frequency antenna 14 is configured as a coil, in which case the high frequency connections 24 can be configured as conductive leads 28 (as shown in Figure 1 ) that can be coupled to the coil. In Figure 1In an embodiment, the UHF antenna 16 is configured as a slotted-loop antenna, in which case the UHF connection 26 can be configured as a conductive pad 30 (as shown in Figure 1

[0029] As mentioned above, the nature and configuration of the antenna connection of the RFID coupling strap 15 can vary depending on the nature and configuration of the associated antenna. As an example, Figure 4 A dual-mode RFID device 10' is shown having a UHF antenna 16' configured differently. In Figure 4 In an embodiment, the UHF antenna 16' is not configured to connect with the RFID coupling strap 15' at a conductive pad, but is configured to be coupled to the RFID coupling strap 15' without physical contact between the UHF antenna 16' and the RFID coupling strap 15'. In other words, the RFID coupling strap 15' is configured as a reactive strap, and the conductive loop 13' is coupled to the RFID chip component to effectively couple the UHF antenna 16' (which can be configured as a dipole antenna) to the integrated dual-mode RFID strap 11'. In this embodiment, the integrated dual-mode RFID strap 11' is magnetically coupled to the UHF antenna 16'.

[0030] While Figure 4 While the conductive loop 13' is shown completely separate from the HF antenna 14 (which is shown configured as a coil), it is within the scope of the present application for the HF antenna to define a portion of the conductive loop (as shown in Figure 5 Figure 5 In an embodiment, the HF antenna 14 is configured as a coil coupled to the RFID chip component 12. The conductor 36 has a first end and a second end coupled to the HF antenna 14 on opposite sides of the RFID chip component 12. With this configuration, the portions 38 and 40 of the HF antenna 14 extending between the conductor 36 and the RFID chip component 12 at the junctions of the conductor 36 and the HF antenna 14 and the conductor 36 form a conductive loop. The conductive loop / conductor 36 resonates with the RFID chip component 12 at the desired HF frequencies (e.g., 900 MHz), but the voltage associated with HF operation is shorted around the RFID chip component 12 by the low inductance bridge.

[0031] ​​Regardless of the particular configuration of the dual-mode radio frequency identification device 10, 10', the ultra-high frequency antenna 16, 16' is formed using a method other than etching, which is relatively expensive and can be slower than other methods. In one embodiment, the ultra-high frequency antenna 16, 16' is formed via a cutting operation, such as die-cutting (e.g., from a paper / foil structure) and / or laser cutting. In another embodiment, the ultra-high frequency antenna 16, 16' is formed via a printing operation. It should be understood that the cutting and printing are exemplary low-cost methods of forming the ultra-high frequency antenna 16, 16', and are not an exhaustive list of possible methods. Rather, it should be understood that the present application encompasses any method of forming the ultra-high frequency antenna that is less costly than forming the same ultra-high frequency antenna via an etching operation.

[0032] Once formed, the ultra-high frequency antenna 16, 16' can then be coupled to the integrated dual-mode radio frequency identification strap 11, 11' according to any suitable method, which can include coupling the ultra-high frequency antenna 16, 16' to the radio frequency identification coupling strap 15, 15' using an adhesive material (such as a pressure sensitive glue), which allows the ultra-high frequency antenna 16, 16' to be quickly connected to the radio frequency identification coupling strap 15, 15'. In the case of the conductive pad 30 (as shown in FIG. 3), a thin layer of adhesive is applied between the conductive pad 30 and the ultra-high frequency antenna 16, and the ultra-high frequency antenna 16 is coupled to the conductive pad 30 via capacitance. Figure 1

[0033] One consideration when employing a radio frequency identification chip assembly 12 having an ultra-high frequency radio frequency identification chip 20 and a high frequency radio frequency identification chip 22 is the separation between the two chips 20 and 22. According to a conventional method of integrating a pair of radio frequency identification chips into a dual-mode radio frequency identification device, the chip attach system transfers one chip from a wafer at a time, so attaching two chips requires two passes through the system. As part of the chip attach process, an anisotropic conductive paste is provided under the chip, the chip is pushed into the paste and heated by a hot bar, which cures the adhesive. If the separation between the two chips is less than the size of the portion of the hot bar used to secure the second chip, the hot bar will stop at the height of the attachment of the first chip, which can prevent proper engagement of the second chip with the structure of the radio frequency identification device.

[0034] Accordingly, in some embodiments, the limitations of the conventional chip attach process described above can be overcome by providing a first chip 42 and a second chip 44 having different heights, as shown in FIG. 4. In this embodiment, the first chip 42 is attached to the radio frequency identification device 10, 10' using a first hot bar 46, which is sized to attach the first chip 42 to the radio frequency identification device 10, 10' at a first height. The second chip 44 is attached to the radio frequency identification device 10, 10' using a second hot bar 48, which is sized to attach the second chip 44 to the radio frequency identification device 10, 10' at a second height that is lower than the first height. In this manner, the second chip 44 can be attached to the radio frequency identification device 10, 10' without interfering with the attachment of the first chip 42. Figure 6 ​The height "H" of the second chip 44 is greater than the height "h" of the first chip 42, such that the first chip 42 does not interfere with the heat stakes that are used to secure the second chip 44 to the structure 46 of the dual-mode radio frequency identification device. With such an arrangement, the spacing "d" between the two chips 42 and 44 can be less than the size of the portion of the heat stakes that are used to secure the second chip 44, in which case at least a portion of the first chip 42 will be positioned between the heat stakes and the structure 46 of the dual-mode radio frequency identification device when the second chip 44 is secured. The closer positioning of the two radio frequency identification chips 42 and 44 makes it possible to create a smaller dual-mode radio frequency identification strap, which can reduce the cost of the radio frequency identification strap.

[0035] The heights "h" and "H" of the two chips 42 and 44 can vary without departing from the scope of the present application, so long as the second chip 44 has a height that is greater than the height of the first chip 42. In one example embodiment, the first chip 42 has a height "h" of approximately 75 μm, while the second chip 44 has a height "H" of approximately 125 μm. For example, the second chip 44 can be configured to have a height "H" that is a particular percentage greater than the height "h" of the first chip 42, such as at least 10% greater, or at least 25% greater, or at least 50% greater. In another embodiment, the second chip 44 can be configured to have a height "H" that is a particular amount greater than the height "h" of the first chip 42, such as at least 25 μm greater than the height "h" of the first chip 42, or at least 50 μm greater than the height "h" of the first chip 42. The particular height difference between the two chips 42 and 44 can be selected based on any of a number of factors, such as the properties of the adhesive that is employed and the configuration of the heat stake system (e.g., the amount of heat and pressure to be applied). It should be understood that this aspect of the present application is not limited to use with dual-mode radio frequency identification devices having an ultra-high frequency antenna formed according to any particular method, but can be used more generally with any dual-mode radio frequency identification device having a pair of radio frequency identification chips.

[0036] In some embodiments, a sequential testing approach can be employed to reduce the cost associated with a chip attach failure or a failed chip for a dual-mode RFID device having a pair of RFID chips. A first chip is attached to the structure of the dual-mode RFID device in any suitable manner. The first chip is then subjected to a first test to determine if it has any problems (e.g., due to a failed chip attach or due to a failed chip itself). If the first chip fails the test, the RFID device is considered defective and is discarded without the need to secure a second chip (securing a second chip would unnecessarily increase the cost associated with a first chip failure). On the other hand, if the first chip passes the first test, a second chip can be secured to the structure of the dual-mode RFID device in any suitable manner. The second chip is then subjected to a second test to determine if it has any problems. If the second chip fails the test, the RFID device is considered defective and is discarded. Otherwise, if the second chip passes the test, the dual-mode RFID device can be accepted.

[0037] During the process of securing the second chip to the structure of the dual-mode RFID device, the first chip can be damaged. Thus, it can be advantageous to not only test the second chip after it is secured, but also to subject the first chip to a third test (which is a second test applied to the first chip). If the first chip fails the third test and / or the second chip fails the second test, the dual-mode RFID device is discarded. On the other hand, if the second chip passes the second test and the first chip passes the third test, the dual-mode RFID device is accepted. It should be understood that the nature of the tests can vary without departing from the scope of the present application. (In embodiments where the first chip is tested twice) this can include subjecting the first chip to two identical tests, or different tests before and after the second chip has been secured.

[0038] If the chips are integrated into an integrated dual-mode RFID strap (e.g., one of the types described herein), the second and third tests can be performed on the strap, or both tests or one of them can be performed after the strap is coupled to an antenna. This can include subjecting the two chips or one of them to a test between the processes of attaching the second chip and coupling to the antenna, and after coupling to the antenna.

[0039] The configuration of the integrated dual-mode RFID strap of the present application enables easy manufacturing of a large number of RFID tags with varying configurations while using a common integrated dual-mode RFID strap. The use of die cutting or laser cutting methods to form the UHF antenna also enables minimizing material waste. Thus, the dual-mode RFID device of the present application is designed to be a sustainable device.

[0040] It is to be understood that the embodiments described above are merely illustrative of the principles of the present application. Numerous modifications can be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including that which is disclosed in this document individually or in any combination. For these reasons, the scope of the present application is not limited to the above description, but is instead as set forth in the appended claims, and it is to be understood that the claims can be directed to features individually or in combination.

Claims

1. A method of manufacturing a dual-mode radio frequency identification device, the method comprising: preparing a radio frequency identification chip assembly, securing a first radio frequency identification chip to a structure of the dual-mode radio frequency identification device using a hot bar to apply heat and pressure between the first radio frequency identification chip and the structure; and securing a second radio frequency identification chip to the structure using the hot bar to apply heat and pressure between the second radio frequency identification chip and the structure, wherein at least a portion of the first radio frequency identification chip is positioned between the hot bar and the structure. The second radio frequency identification chip has a thickness that is greater than a thickness of the first radio frequency identification chip.

2. The method of claim 1, wherein, The second radio frequency identification chip has a thickness that is at least 50% greater than a thickness of the first radio frequency identification chip.

3. The method of claim 2, wherein, The second radio frequency identification chip has a thickness of 125 pm and the first radio frequency identification chip has a thickness of 75 pm.

4. The method of claim 2 or 3, wherein, 5. The method of any one of claims 1-4, wherein securing the first radio frequency identification chip to the structure using the hot bar comprises first passing the structure through a hot bar apparatus, securing the second radio frequency identification chip to the structure using the hot bar comprises second passing the structure through the hot bar apparatus.

6. The method of any one of claims 1-5, further comprising: after securing the first radio frequency identification chip to the structure, subjecting the first radio frequency identification chip to a first test; if the first radio frequency identification chip passes the first test, proceeding with securing the second radio frequency identification chip to the structure; or if the first radio frequency identification chip fails the first test, discarding the dual-mode radio frequency identification device without securing the second radio frequency identification chip to the structure.

7. The method of claim 6, further comprising: after securing the second radio frequency identification chip to the structure, subjecting the second radio frequency identification chip to a second test; if the second radio frequency identification chip fails the second test, discarding the dual-mode radio frequency identification device; or when the second radio frequency identification chip passes the second test, accepting the dual-mode radio frequency identification device.

8. The method of claim 7, further comprising: after securing the second radio frequency identification chip to the structure, subjecting the second radio frequency identification chip to a second test and subjecting the first radio frequency identification chip to a third test; when the second radio frequency identification chip fails the second test and / or the first radio frequency identification chip fails the third test, discarding the dual-mode radio frequency identification device; or when the second radio frequency identification chip passes the second test and the first radio frequency identification chip passes the third test, accepting the dual-mode radio frequency identification device. ​

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