Dual-mode RFID devices

Abstract

A dual-mode radio frequency identification (RFID) device is configured to have an integrated dual-mode RFID connection strip, the integrated dual-mode RFID connection strip including: an ultra-high frequency / high frequency (UHF / HF) dual-mode RFID chip, or a combination of an UHF RFID chip and an HF RFID chip. Both a high frequency (HF) antenna and an ultra-high frequency (UHF) antenna are coupled to the integrated dual-mode RFID connection strip, and the UHF 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 used, one of the chips in the pair can have a greater thickness than the other chip, allowing the thicker chip to be integrated into the device after the thinner chip, without requiring a minimum spacing between the two chips due to the size of the hot plate used to fix the chips. In addition, the first chip can be tested before the second chip is fixed, thereby limiting the cost of discarded devices.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 954,455, filed on December 28, 2019, which is incorporated herein by reference in its entirety. Technical Field

[0003] 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 Art

[0004] Radio frequency identification devices contain an integrated circuit (or chip) and an antenna and are widely used to associate an object with a unique identification code. The antenna sends and receives signals transmitted at a specific frequency or within a specific frequency band. For example, an radio frequency identification device can be configured to send and receive signals within the high frequency ("HF") frequency band (i.e., signals having a frequency in the range of approximately 3 MHz to 30 MHz) or within the ultra-high frequency ("UHF") frequency band (i.e., signals having a frequency in the range of approximately 300 MHz to 3000 MHz). More specifically, high frequency radio frequency identification devices tend to operate at frequencies at or around 13.56 MHz, while ultra-high frequency radio frequency identification devices tend to operate at frequencies in the range of approximately 866 MHz to 915 MHz (or 902 MHz to 928 MHz in North America).

[0005] In many applications, it is desirable to employ an RFID device that operates in multiple frequency bands, such as HF and UHF. U.S. Patent No. 9,871,294 describes an exemplary dual-frequency RFID device, which is incorporated herein by reference. The dual-frequency RFID device can be configured differently, such as employing a dual-mode RFID chip electrically coupled to a pair of antennas that are configured to transmit and receive signals in different frequency bands according to a method. Alternatively, the dual-frequency RFID device includes a first chip / antenna pair and a second chip / antenna pair, wherein the first pair and the second pair operate in different frequency bands.

[0006] High-frequency antennas are often made using etching processes due to their smaller geometry and the need for connections between the inside and outside of the coil (bridges) or interconnections to a second coil antenna on the other side of the substrate via a substrate (crimips). For similar reasons, UHF straps (containing a pair of conductive pads configured to electrically couple to a UHF antenna and an RFID chip) are also commonly etched. However, while etching techniques have proven effective in creating RFID devices, they can be expensive compared to other methods. Summary of the Invention

[0007] The present invention has several aspects that may be embodied individually or together in the devices and systems described and claimed below. These aspects may 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 exclude the use of these aspects alone or the claiming of these aspects alone or in various combinations (as may be listed herein along with the claims).

[0008] A dual-mode RFID device is described herein, comprising an integrated RFID strap with dual-mode capabilities. In some embodiments, the strap is configured as a reactive strap and includes a high-frequency antenna and a conductive loop coupled to an RFID chip assembly. In some embodiments, the strap is configured to couple to an ultra-high frequency (UHF) antenna without physical contact between the UHF antenna and the strap.

[0009] In some embodiments, the integrated dual-mode RFID connection strip, which includes the high-frequency antenna and the conductive loop coupled to the RFID chip assembly, is on a single substrate.

[0010] In some embodiments, the integrated dual-mode RFID connection strip is configured as the aforementioned reactive connection strip, and is magnetically, conductively, and / or capacitively coupled to the UHF antenna.

[0011] In some embodiments, the RFID chip assembly of the integrated dual-mode RFID strap includes an RFID coupling strap and a dual-mode RFID chip. In one embodiment, the dual-mode RFID chip includes an ultra-high frequency / high frequency dual-mode RFID chip. In another embodiment, the dual-mode RFID chip includes a combination of an ultra-high frequency RFID chip and a high frequency RFID chip, with each chip individually disposed on the RFID coupling strap.

[0012] In some embodiments, the integrated dual-mode RFID connection strip includes a conductive ring and a high-frequency antenna attached to the RFID coupling connection strip by an adhesive material including a pressure-sensitive adhesive.

[0013] Also described herein is a method for manufacturing a dual-mode RFID device. In some embodiments, the method includes providing an integrated dual-mode RFID connecting strip having an RFID chip component, the RFID chip component comprising: 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 connecting strip further comprises: a conductive ring and a high frequency antenna affixed, attached, or coupled to the RFID chip component. In some embodiments, the high frequency antenna and the conductive ring are coupled to the RFID chip component at opposite ends thereof. In one embodiment, the conductive ring is an ultra-high frequency (UHF) ring. In some embodiments, the presence of the conductive ring as part of the integrated dual-mode RFID connecting strip enables the connecting strip to couple with the ultra-high frequency antenna. In some embodiments, the ultra-high frequency antenna is formed without etching.

[0014] 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 using a thermode to apply heat and pressure between the first RFID chip and the structure. In some embodiments, the thermode is then used to secure a second RFID chip to the structure, with at least a portion of the first RFID chip positioned between the thermode and the structure.

[0015] 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, securing a second RFID chip to the structure, and then subjecting the second RFID chip 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 THE DRAWINGS

[0016] Figure 1 is a schematic diagram of an exemplary dual-mode radio frequency identification device according to one aspect of the present invention.

[0017] Figure 2 yes Figure 1 A schematic diagram of a first exemplary embodiment of an RFID connection strip of a dual-mode RFID device employing an UHF / HF dual-mode RFID chip.

[0018] Figure 3 yes Figure 1 FIG2 is a schematic diagram of a second exemplary embodiment of an RFID connection strip of a dual-mode RFID device, which uses a combination of an UHF RFID chip and a HF RFID chip.

[0019] Figure 4 FIG. 1 is a schematic diagram of another embodiment of an exemplary dual-mode radio frequency identification device according to an aspect of the present invention.

[0020] Figure 5 yes Figure 4 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 loop of the dual-mode RFID device.

[0021] Figure 6 is a schematic diagram of an exemplary embodiment of a pair of RFID chips that can be integrated into a dual-mode RFID device according to one aspect of the present invention. DETAILED DESCRIPTION

[0022] 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 by the scope of the claims.

[0023] Figure 1 A dual-mode RFID device 10 (e.g., an RFID tag or label) according to one aspect of the present invention is shown. The dual-mode RFID device 10 includes an integrated dual-mode RFID connection strip 11 configured to couple with an ultra-high frequency 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 can achieve coupling between the high-frequency antenna 14 and the ultra-high frequency 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 can also be used.

[0024] Figure 2An RFID chip assembly 12 is shown, which includes an RFID coupling strap 15, a conductive pad 30, and one or more RFID chips. The RFID chip assembly 12 is coupled to a high-frequency antenna 14 on one side and to a conductive ring 13 on the other side. In particular, the high-frequency antenna 14 and the conductive ring 13 are attached to the RFID coupling strap 15. In one embodiment, an adhesive material (such as a pressure-sensitive adhesive) is used to couple, attach, or attach the high-frequency antenna 14 and the conductive ring 13 to the RFID coupling strap 15. The high-frequency antenna 14, the conductive ring 13, and the RFID chip assembly 12 that couples the high-frequency antenna 14 and the conductive ring 13 are integrated into a common substrate, while the integrated dual-mode RFID strap 11, which serves as a "combo strap," is separate from the ultra-high frequency antenna 16.

[0025] The one or more RFID chips of the RFID chip assembly 12 include: a single UHF / HF dual-mode RFID chip 18 ( Figure 2 ), or, a combination of an UHF RFID chip 20 and a HF RFID chip 22 ( Figure 3 Many aspects of the present invention can be used with an RFID coupling strip 15 having one or two RFID chips. However, certain aspects of the present invention are particularly applicable to an RFID coupling strip 15 having a pair of RFID chips 20 and 22, as will be described in more detail herein.

[0026] Regardless of the specific configuration of the RFID chip assembly 12 , the integrated dual-mode RFID connection strip 11 is configured for coupling to both the HF antenna 14 and the UHF antenna 16 . Figure 2 and Figure 3 Shown: RFID coupling connection strip 15, which has (with UHF / HF dual-mode RFID chip 18 ( Figure 2 ) or high frequency radio frequency identification chip 22 ( Figure 3 ) associated with a pair of high frequency connections 24 and (with the UHF / HF dual mode RFID chip 18 ( Figure 2 ) or UHF RFID chip 20 ( Figure 3 ) associated with a pair of UHF connections 26.

[0027] The nature and configuration of the HF connection 24 and the UHF connection 26 may vary depending on the nature and configuration of the associated antennas. Figure 1 In the embodiment of the present invention, the high frequency antenna 14 is configured as a coil, in which case the high frequency connection 24 can be configured as a conductive lead 28 (such as a conductive lead) that can be coupled to the coil. Figure 1 ). Figure 1In the embodiment of the present invention, the UHF antenna 16 is configured as a slotted-loop antenna. In this case, the UHF connection 26 can be configured to be coupled to the conductive pad 30 of the slotted-loop antenna (e.g., Figure 1 shown).

[0028] As mentioned above, the nature and configuration of the antenna connections of the RFID coupling strip 15 may 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 differently configured UHF antenna 16'. Figure 4 In the embodiment of the present invention, the UHF antenna 16' is not configured to connect to the RFID coupling strip 15' at the conductive pad, but is instead configured to couple to the RFID coupling strip 15' without physical contact between the UHF antenna 16' and the RFID coupling strip 15'. In other words, the RFID coupling strip 15' is configured as a reactive strip, while the conductive ring 13' is coupled to the RFID chip assembly to effectively couple the UHF antenna 16' (which may be configured as a dipole antenna) to the integrated dual-mode RFID strip 11'. In this embodiment, the integrated dual-mode RFID strip 11' is magnetically coupled to the UHF antenna 16'.

[0029] Although Figure 4 The conductive loop 13' is shown completely separate from the high frequency antenna 14 (which is shown configured as a coil), but the high frequency antenna defines a portion of the conductive loop (eg Figure 5 shown) is within the scope of the present invention. Figure 5 In the embodiment of the present invention, the high-frequency antenna 14 is configured as a coil coupled to the RFID chip assembly 12. A conductor 36 has a first end and a second end, which are coupled to the high-frequency antenna 14 on opposite sides of the RFID chip assembly 12. With this configuration, portions 38 and 40 of the high-frequency antenna 14, extending between the RFID chip assembly 12 at the junction of the conductor 36 and the high-frequency antenna 14, and the conductor 36 form a conductive loop. The conductive loop / conductor 36 resonates with the RFID chip assembly 12 at a desired high frequency (e.g., 900 MHz), but the voltage associated with high-frequency operation is relatively short around the RFID chip assembly 12 via a low-inductance bridge.

[0030] Regardless of the specific configuration of the dual-mode RFID device 10, 10', the UHF antenna 16, 16' is formed using a method other than etching, which is relatively expensive and may be slower than other methods. In one embodiment, the UHF 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 UHF 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 UHF antenna 16, 16', rather than an exhaustive list of possible methods. On the contrary, it should be understood that the present invention encompasses any method of forming an UHF antenna that is less expensive than the cost of forming the same UHF antenna via an etching operation.

[0031] Once formed, the UHF antenna 16, 16' can then be coupled to the integrated dual-mode RFID connection strips 11, 11' according to any suitable method, which may include coupling the UHF antenna 16, 16' to the RFID coupling connection strips 15, 15' using an adhesive material (such as a pressure sensitive adhesive), which allows the UHF antenna 16, 16' to be quickly connected to the RFID connection strips 15, 15'. In the case of the conductive pad 30 (such as Figure 1 ), a thin layer of adhesive is applied between the conductive pad 30 and the UHF antenna 16, and the UHF antenna 16 is coupled to the conductive pad 30 via capacitance.

[0032] One consideration when using an RFID chip assembly 12 having an UHF RFID chip 20 and an HF RFID chip 22 is the separation between the two chips 20 and 22. According to a conventional method of integrating a pair of RFID chips into a dual-mode RFID device, a chip attach system transfers one chip at a time from a wafer, so attaching the two chips requires two passes through the system. As part of the chip attach process, an anisotropic conductive paste is provided under the chip, into which the chip is pushed and heated by a hot plate, thereby curing the adhesive. If the separation between the two chips is smaller than the size of the portion of the hot plate used to secure the second chip, the hot plate will stop at the attachment height of the first chip, which may prevent the second chip from properly bonding to the structure of the RFID device.

[0033] Therefore, in some embodiments, the limitations of the conventional chip attach process described above may be overcome by providing the first chip 42 and the second chip 44 with different heights, such as Figure 6As shown. The height "H" of the second chip 44 is greater than the height "h" of the first chip 42, so that the first chip 42 does not interfere with the hot plate that attempts to secure the second chip 44 to the structure 46 of the dual-mode RFID device. With this arrangement, the spacing "d" between the two chips 42 and 44 can be smaller than the size of the portion of the hot plate used to secure the second chip 44. In this case, when the second chip 44 is secured, at least a portion of the first chip 42 will be positioned between the hot plate and the structure 46 of the dual-mode RFID device. The closer positioning of the two RFID chips 42 and 44 allows for the creation of a smaller dual-mode RFID connection ribbon, which can reduce the cost of the RFID connection ribbon.

[0034] The heights "h" and "H" of the two chips 42 and 44 may vary without departing from the scope of the present invention, as long as the second chip 44 has a height that is greater than the height of the first chip 42. In one exemplary 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 may be configured to have a height "H" that is a specific 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 may be configured to have a height "H" that is a specific 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 specific height difference between the two chips 42 and 44 may be selected based on any of a number of factors, such as the properties of the adhesive employed and the configuration of the thermocouple system (e.g., the amount of heat and pressure to be applied). It should be understood that this aspect of the present invention is not limited to use with dual-mode RFID devices having UHF antennas formed according to any particular method, but is more generally applicable to any dual-mode RFID device having a pair of RFID chips.

[0035] In some embodiments, a sequential testing method can be used to reduce the costs associated with chip attachment failures or faulty chips in 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 according to any suitable method. The first chip is then subjected to a first test to determine whether it has any problems (e.g., due to chip attachment failure or due to a failure of the chip itself). If the first chip fails the test, the RFID device is considered defective and discarded without the need to fix the second chip (fixing the second chip would unnecessarily increase the costs associated with the failure of the first chip). On the other hand, if the first chip passes the first test, the second chip can be fixed to the structure of the dual-mode RFID device according to any suitable method. The second chip is then subjected to a second test to determine whether it has any problems. If the second chip fails the test, the RFID is considered defective and discarded. Otherwise, if the second chip passes the test, the dual-mode RFID device can be accepted.

[0036] In the process of fixing the second chip to the structure of the dual-mode RFID device, the first chip may be damaged. Therefore, it may be advantageous not only to test the second chip after it is fixed, but also to subject the first chip to a third test (which is the 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 test may vary without departing from the scope of the present invention. (In an embodiment where the first chip is tested twice) this may include: the first chip undergoing the same test twice, or undergoing different tests before and after the second chip has been fixed.

[0037] If the chip is incorporated into an integrated dual-mode RFID connection strip (e.g., one of the types described herein), the second and third tests may be performed on the connection strip, or one or both of the tests may be performed after the connection strip is coupled to the antenna. This may include testing one or both of the chips between attaching the second chip and coupling to the antenna, and after coupling to the antenna.

[0038] The configuration of the integrated dual-mode RFID ribbon of the present invention allows for the easy manufacture of numerous RFID tags with varying configurations while utilizing a common integrated dual-mode RFID ribbon. The use of die-cutting or laser cutting methods to form the UHF antenna also minimizes material waste. Consequently, the dual-mode RFID device of the present invention is designed to be sustainable.

[0039] It will be appreciated that the embodiments described above illustrate some applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter (including combinations of those features disclosed or claimed herein). For these reasons, the scope of the present invention is not limited to the above description, but is as set forth in the accompanying claims, and it will be appreciated that the claims may be directed to features of the present invention, including combinations of features disclosed or claimed herein.

Claims

1. A dual-mode radio frequency identification device, comprising: Radio frequency identification chip components; as well as An integrated dual-mode RFID connection strip comprising a high-frequency antenna and a conductive ring coupled to the RFID chip assembly, wherein the integrated dual-mode RFID connection strip is coupled to an UHF antenna; The RFID chip assembly includes an RFID coupling connection strip, and the coupling connection strip includes one or more RFID chips arranged thereon. The one or more RFID chips are a combination of an ultra-high frequency RFID chip and a high frequency RFID chip of different heights.

2. The dual-mode radio frequency identification device according to claim 1, wherein: The connecting strip is coupled to the UHF antenna via a conductive pad.

3. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The conductive ring includes an ultra-high frequency ring.

4. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The integrated dual-mode RFID connection strip is coupled to the UHF antenna without physical contact between the UHF antenna and the integrated dual-mode RFID connection strip.

5. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The RFID chip assembly is coupled to the high frequency antenna on one side and to the conductive loop on the other side.

6. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The high-frequency antenna includes a coil antenna.

7. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The conductive ring, the radio frequency identification chip component and the high frequency antenna are embedded on a single substrate.

8. The dual-mode radio frequency identification device according to claim 7, wherein: A portion of the conductive loop is defined as the high-frequency antenna.

9. The dual-mode radio frequency identification device according to claim 1, wherein: The one or more RFID chips are single UHF-HF dual-mode RFID chips.

10. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The integrated dual-mode RFID connection strip is capacitively coupled to the UHF antenna.

11. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The integrated dual-mode RFID connection strip is conductively coupled to the UHF antenna.

12. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The integrated dual-mode RFID connection strip is magnetically coupled to the UHF antenna.

13. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The UHF antenna is a slotted loop antenna.

14. The dual-mode radio frequency identification device according to claim 1 or 2, wherein: The conductive ring is coupled, attached, or affixed to the RFID coupling strip via an adhesive material.

15. The dual-mode radio frequency identification device according to claim 14, wherein: The conductive ring is coupled to the dual-mode RFID connection strip via pressure-sensitive adhesive.

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