WO2026011005A1 - Self-aligned antenna gap fiducial marks - Google Patents

Abstract

A method for assembling radio tags is provided. A tag substrate may include a planar mounting material, a planar antenna formed on the planar mounting material, and a first fiducial mark formed on the planar mounting material. Cuts may be formed at an IC assembly region of the planar antenna, to form an antenna gap, and on the first fiducial mark. An adhesive may be applied to the antenna gap, and a radio IC may be optically aligned across the antenna gap by using the cut on the first fiducial mark. The aligned radio IC may be attached to the planar antenna using the adhesive such that the radio IC bridges the antenna gap.

Description

SELF-ALIGNED ANTENNA GAP FIDUCIAL MARKS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 63/668,132 filed on July 5, 2025. The disclosures of the Provisional Application are hereby incorporated by reference in their entirety.

BACKGROUND

[0002] Radio-Frequency Identification (RFID) systems typically include RFID readers, also known as RFID reader/writers or RFID interrogators, and RFID tags, also known as radio tags. RFID systems can be used in many ways for locating and identifying objects to which the tags are attached. RFID systems are useful in product- related and service-related industries for tracking objects being processed, inventoried, or handled. In such cases, an RFID tag is usually attached to an individual item, or to its package. The RFID tag typically includes, or is, a radiofrequency (RF) integrated circuit (IC). Such an RFIC may be referred to as an RFID IC or a radio IC.

[0003] In principle, RFID techniques entail using an RFID reader to inventory one or more RFID tags, where inventorying involves singulating a tag, receiving an identifier from a tag, and/or acknowledging a received identifier (e.g., by transmitting an acknowledge command). “Singulated” is defined as a reader singling-out one tag, potentially from among multiple tags, for a reader-tag dialog. “Identifier” is defined as a number identifying the tag or the item to which the tag is attached, such as a tag identifier (TID), electronic product code (EPC), etc. An “inventory round” is defined as a reader staging RFID tags for successive inventorying. The reader transmitting an RF wave performs the inventory. The RF wave is typically electromagnetic, at least in the far field. The RF wave can also be predominantly electric or magnetic in the near or transitional near field. The RF wave may encode one or more commands that instruct the tags to perform one or more actions. The operation of an RFID reader sending commands to an RFID tag is sometimes known as the reader “interrogating” the tag.

[0004] In typical RFID systems, an RFID reader transmits a modulated RF inventory signal (a command), receives a tag reply, and transmits an RF acknowledgement signal responsive to the tag reply. A tag that replies to the interrogating RF wave does so by transmitting back another RF wave. The tag either generates the transmitted back RF wave originally, or by reflecting back a portion of the interrogating RF wave in a process known as backscatter. Backscatter may take place in a number of ways.

[0005] RFID tags are assembled by placing a radio IC with at least two IC contacts across a gap between two antenna terminals on a tag substrate such that the IC electrically contacts both antenna terminals, but each IC contact on the IC electrically contacts one and only one antenna terminal. As radio ICs become smaller, the maximum allowable size of the gap between the two antenna terminals on the tag substrate also becomes smaller. The smaller the gap, the more difficult it is to create and maintain the gap while depositing antenna material on the tag substrate.

BRIEF SUMMARY

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0007] Examples are directed to a method for assembling radio tags. The method can include receiving a tag substrate including a planar mounting material, a planar antenna formed on the mounting material and having an IC assembly region, and a first fiducial mark formed on the mounting material and proximal to the planar antenna. The method may also include forming cuts on both the IC assembly region and the first fiducial mark, wherein the cut on the IC assembly region bisects the IC assembly region to form an antenna gap. The method may additionally include applying an adhesive to the antenna gap that at least partially obscures the antenna gap but does not obscure the cut on the first fiducial mark. The method further includes optically aligning a radio IC across the antenna gap using at least the cut on the first fiducial mark and attaching the aligned radio IC to the planar antenna using the adhesive such that the radio IC bridges the antenna gap.

[0008] These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of aspects as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following Detailed Description proceeds with reference to the accompanying drawings, in which:

[0010] FIG. l is a block diagram of components of an RFID system.

[0011] FIG. 2 is a diagram showing components of a passive RFID tag, such as a tag that can be used in the system of FIG. 1.

[0012] FIG. 3 is a conceptual diagram for explaining a half-duplex mode of communication between the components of the RFID system of FIG. 1.

[0013] FIG. 4 is a block diagram showing a detail of an RFID tag, such as the one shown in FIG. 2.

[0014] FIG. 5A and 5B illustrate signal paths during tag-to-reader and reader-to-tag communications in the block diagram of FIG. 4.

[0015] FIG. 6A and 6B depict RFID IC alignment across an antenna gap.

[0016] FIG. 7A and 7B depict an IC-less tag substrate with an antenna and fiducial marks.

[0017] FIG. 8 depicts an IC-less tag substrate with an antenna after a centered linear cut bisects both an IC assembly region, forming an antenna gap, and a fiducial mark, according to embodiments.

[0018] FIG. 9 depicts an IC-less tag substrate with an antenna after a shifted linear cut bisects an IC assembly region to form an antenna gap and also at least partially bisects two fiducial marks, according to embodiments.

[0019] FIG. 10 depicts an IC-less tag substrate with an antenna after an angled linear cut bisects an IC assembly region and two fiducial marks, according to embodiments.

[0020] FIG. 11 depicts different cutting schemes for fiducial mark cuts and antenna gaps, according to embodiments.

[0021] FIG. 12 depicts different patterns for forming additional cuts in an antenna, according to embodiments. [0022] FIG. 13 illustrates a flow diagram of a method for assembling an RFID or radio tag, according to embodiments.

DETAILED DESCRIPTION

[0023] In the following detailed description, references are made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments or examples. These embodiments or examples may be combined, other aspects may be utilized, and structural changes may be made without departing from the spirit or scope of the present disclosure. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

[0024] As used herein, “memory” is one of ROM, RAM, SRAM, DRAM, NVM, EEPROM, FLASH, Fuse, MRAM, FRAM, and other similar volatile and nonvolatile information-storage technologies. Some portions of memory may be writeable and some not. “Instruction” refers to a request to a tag to perform a single explicit action (e.g., write data into memory). “Command” refers to a reader request for one or more tags to perform one or more actions and includes one or more tag instructions preceded by a command identifier or command code that identifies the command and/or the tag instructions. “Program” refers to a request to a tag to perform a set or sequence of instructions (e.g., read a value from memory and, if the read value is less than a threshold then lock a memory word). “Protocol” refers to an industry standard for communications between a reader and a tag (and vice versa). One such protocol is the Class- 1 Generation-2 UHF RFID Protocol for Communications at 860 MHz - 960 MHz by GS1 EPCglobal, Inc. (“the Gen2 Protocol”), versions up to 3.0 of which are hereby incorporated by reference. Another protocol is the ISO/IEC 18000-63 Information technology - Radio frequency identification for item management - Part 63 : Parameters for air interface communications at 860 MHz to 960 MHz Type C (“ISO/IEC 18000-63”), also hereby incorporated by reference.

[0025] FIG. 1 is a diagram of the components of a typical RFID system 100, incorporating embodiments. An RFID reader 110 and a nearby RFID tag 120 communicate via RF signals 112 and 126. When sending data to tag 120, reader 110 may generate RF signal 112 by encoding the data, modulating an RF waveform with the encoded data, and transmitting the modulated RF waveform as RF signal 112. In turn, tag 120 may receive RF signal 112, demodulate encoded data from RF signal 112, and decode the encoded data. Similarly, when sending data to reader 110 tag 120 may generate RF signal 126 by encoding the data, modulating an RF waveform with the encoded data, and causing the modulated RF waveform to be sent as RF signal 126. The data sent between reader 110 and tag 120 may be represented by symbols, also known as RFID symbols. A symbol may be a delimiter, a calibration value, or implemented to represent binary data, such as “0” and “1”, if desired. Upon processing by reader 110 and tag 120, symbols may be treated as values, numbers, or any other suitable data representations.

[0026] The RF waveforms transmitted by reader 110 and/or tag 120 may be in a suitable range of frequencies, such as those near 900 MHz, 13.56 MHz, or similar. In some embodiments, RF signals 112 and/or 126 may include non-propagating RF signals, such as reactive near-field signals or similar. RFID tag 120 may be active or battery -assisted (i.e., possessing its own power source), or passive. In the latter case, RFID tag 120 may harvest power from RF signal 112.

[0027] FIG. 2 is a diagram of an RFID tag 220, which may function as tag 120 of FIG. 1. Tag 220 may be formed on a substantially planar inlay 222, which can be made in any suitable way. Tag 220 includes a circuit which may be implemented as an RF, RFID, RFID tag, or radio IC 224. In some embodiments IC 224 is fabricated in complementary metal-oxide semiconductor (CMOS) technology. In other embodiments IC 224 may be fabricated in other technologies such as bipolar junction transistor (BJT) technology, metal-semiconductor field-effect transistor (MESFET) technology, and others as will be well known to those skilled in the art. IC 224 is arranged on inlay 222.

[0028] Tag 220 also includes an antenna for transmitting and/or interacting with RF signals. In some embodiments the antenna can be etched, deposited, and/or printed metal on inlay 222; conductive thread formed with or without inlay 222; nonmetallic conductive (such as graphene) patterning on inlay 222; a first antenna coupled inductively, capacitively, or galvanically to a second antenna; or can be fabricated in myriad other ways that exist for forming antennas to receive RF waves. In some embodiments the antenna may even be formed in IC 224. Regardless of the antenna type, IC 224 is electrically coupled to the antenna via suitable IC contacts (not shown in FIG. 2). The term “electrically coupled” as used herein may mean a direct electrical connection, or it may mean a connection that includes one or more intervening circuit blocks, elements, or devices. The “electrical” part of the term “electrically coupled” as used in this document shall mean a coupling that is one or more of ohmic/galvanic, capacitive, and/or inductive. Similarly, the terms “electrically isolated” or “electrically decoupled” as used herein mean that electrical coupling of one or more types (e.g., galvanic, capacitive, and/or inductive) is not present, at least to the extent possible. For example, elements that are electrically isolated from each other are galvanically isolated from each other, capacitively isolated from each other, and/or inductively isolated from each other. Of course, electrically isolated components will generally have some unavoidable stray capacitive or inductive coupling between them, but the intent of the isolation is to minimize this stray coupling when compared with an electrically coupled path.

[0029] IC 224 is shown with a single antenna port, comprising two IC contacts electrically coupled to two antenna segments 226 and 228 which are shown here forming a dipole. Many other embodiments are possible using any number of ports, contacts, antennas, and/or antenna segments. Antenna segments 226 and 228 are depicted as separate from IC 224, but in other embodiments the antenna segments may alternatively be formed on IC 224. Tag antennas according to embodiments may be designed in any form and are not limited to dipoles. For example, the tag antenna may be a patch, a slot, a loop, a coil, a horn, a spiral, a monopole, microstrip, stripline, or any other suitable antenna.

[0030] Diagram 250 depicts top and side views of tag 252, formed using a strap. Tag 252 differs from tag 220 in that it includes a substantially planar strap substrate 254 having strap contacts 256 and 258. IC 224 is mounted on strap substrate 254 such that the IC contacts on IC 224 electrically couple to strap contacts 256 and 258 via suitable connections (not shown). Strap substrate 254 is then placed on inlay 222 such that strap contacts 256 and 258 electrically couple to antenna segments 226 and 228. Strap substrate 254 may be affixed to inlay 222 via pressing, an interface layer, one or more adhesives, or any other suitable means.

[0031] Diagram 260 depicts a side view of an alternative way to place strap substrate 254 onto inlay 222. Instead of strap substrate 254’ s surface, including strap contacts 256/258, facing the surface of inlay 222, strap substrate 254 is placed with its strap contacts 256/258 facing away from the surface of inlay 222. Strap contacts 256/258 can then be either capacitively coupled to antenna segments 226/228 through strap substrate 254, or conductively coupled using a through-via which may be formed by crimping strap contacts 256/258 to antenna segments 226/228. In some embodiments, the positions of strap substrate 254 and inlay 222 may be reversed, with strap substrate 254 mounted beneath inlay 222 and strap contacts 256/258 electrically coupled to antenna segments 226/228 through inlay 222. Of course, in yet other embodiments strap contacts 256/258 may electrically couple to antenna segments 226/228 through both inlay 222 and strap substrate 254.

[0032] In operation, the antenna couples with RF signals in the environment and propagates the signals to IC 224, which may both harvest power and respond if appropriate, based on the incoming signals and the IC’s internal state. If IC 224 uses backscatter modulation then it may generate a response signal (e.g., signal 126) from an RF signal in the environment (e.g., signal 112) by modulating the antenna’s reflectance. Electrically coupling and uncoupling the IC contacts of IC 224 can modulate the antenna’s reflectance, as can varying the admittance or impedance of a shunt-connected or series-connected circuit element which is coupled to the IC contacts. If IC 224 is capable of transmitting signals (e.g., has its own power source, is coupled to an external power source, and/or can harvest sufficient power to transmit signals), then IC 224 may respond by transmitting response signal 126. In the embodiments of FIG. 2, antenna segments 226 and 228 are separate from IC 224. In other embodiments, the antenna segments may alternatively be formed on IC 224.

[0033] An RFID tag such as tag 220 is often attached to or associated with an individual item or the item packaging. An RFID tag may be fabricated and then attached to the item or packaging, may be partly fabricated before attachment to the item or packaging and then completely fabricated upon attachment to the item or packaging, or the manufacturing process of the item or packaging may include the fabrication of the RFID tag. In some embodiments, the RFID tag may be integrated into the item or packaging. In this case, portions of the item or packaging may serve as tag components. For example, conductive item or packaging portions may serve as tag antenna segments or contacts. Nonconductive item or packaging portions may serve as tag substrates or inlays. If the item or packaging includes integrated circuits or other circuitry, some portion of the circuitry may be configured to operate as part or all of an RFID tag IC. Thus, an “RFID IC” need not be distinct from an item, but more generally refers to the item containing an RFID IC and antenna capable of interacting with RF waves and receiving and responding to RFID signals. Because the boundaries between IC, tag, and item are thus often blurred, the terms “RFID IC”, “RFID tag”, “tag”, “radio IC”, “radio tag IC”, or “tag IC” as used herein may refer to the IC, the tag, or even to the item as long as the referenced element is capable of RFID functionality.

[0034] The components of the RFID system of FIG. 1 may communicate with each other in any number of modes. One such mode is called full duplex, where both reader 110 and tag 120 can transmit at the same time. In some embodiments, RFID system 100 may be capable of full duplex communication. Another such mode, which may be more suitable for passive tags, is called half-duplex, and is described below.

[0035] FIG. 3 is a conceptual diagram 300 for explaining half-duplex communications between the components of the RFID system of FIG. 1, in this case with tag 120 implemented as a passive tag. The explanation is made with reference to a TIME axis, and also to a human metaphor of “talking” and “listening”. The actual technical implementations for “talking” and “listening” are now described.

[0036] In a half-duplex communication mode, RFID reader 110 and RFID tag 120 talk and listen to each other by taking turns. As seen on axis TIME, reader 110 talks to tag 120 during intervals designated “R- T”, and tag 120 talks to reader 110 during intervals designated “T- R”. For example, a sample R- T interval occurs during time interval 312, during which reader 110 talks (block 332) and tag 120 listens (block 342). A following sample T~>R interval occurs during time interval 326, during which reader 110 listens (block 336) and tag 120 talks (block 346). Interval 312 may be of a different duration than interval 326 - here the durations are shown approximately equal only for purposes of illustration.

[0037] During interval 312, reader 110 transmits a signal such as signal 112 described in FIG. 1 (block 352), while tag 120 receives the reader signal (block 362), processes the reader signal to extract data, and harvests power from the reader signal. While receiving the reader signal, tag 120 does not backscatter (block 372), and therefore reader 110 does not receive a signal from tag 120 (block 382).

[0038] During interval 326, also known as a backscatter time interval or backscatter interval, reader 110 does not transmit a data-bearing signal. Instead, reader 110 transmits a continuous wave (CW) signal, which is a carrier that generally does not encode information. The CW signal provides energy for tag 120 to harvest as well as a waveform that tag 120 can modulate to form a backscatter response signal. Accordingly, during interval 326 tag 120 is not receiving a signal with encoded information (block 366) and instead modulates the CW signal (block 376) to generate a backscatter signal such as signal 126 described in FIG. 2. Tag 120 may modulate the CW signal to generate a backscatter signal by adjusting its antenna reflectance, as described above. Reader 110 then receives and processes the backscatter signal (block 386).

[0039] FIG. 4 is a block diagram showing a detail of an RFID IC, such as IC 224 in FIG. 2. Electrical circuit 424 may be implemented in an IC, such as IC 224. Circuit 424 implements at least two IC contacts 432 and 433, suitable for coupling to antenna segments such as antenna segments 226/228 in FIG. 2. When two IC contacts form the signal input from and signal return to an antenna they are often referred-to as an antenna port. IC contacts 432 and 433 may be made in any suitable way, such as from electrically conductive pads, bumps, or similar. In some embodiments circuit 424 implements more than two IC contacts, especially when configured with multiple antenna ports and/or to couple to multiple antennas.

[0040] Circuit 424 includes signal -routing section 435 which may include signal wiring, signal-routing buses, receive/transmit switches, and similar that can route signals between the components of circuit 424. IC contacts 432/433 may couple galvanically, capacitively, and/or inductively to signal -routing section 435. For example, optional capacitors 436 and/or 438 may capacitively couple IC contacts 432/433 to signal -routing section 435, thereby galvanically decoupling IC contacts 432/433 from signal -routing section 435 and other components of circuit 424.

[0041] Capacitive coupling (and the resultant galvanic decoupling) between IC contacts 432 and/or 433 and components of circuit 424 is desirable in certain situations. For example, in some RFID tag embodiments IC contacts 432 and 433 may galvanically connect to terminals of a tuning loop on the tag. In these embodiments, galvanically decoupling IC contact 432 from IC contact 433 may prevent the formation of a DC short circuit between the IC contacts through the tuning loop. [0042] Capacitors 436/438 may be implemented within circuit 424 and/or partly or completely external to circuit 424. For example, a dielectric or insulating layer on the surface of the IC containing circuit 424 may serve as the dielectric in capacitor 436 and/or capacitor 438. As another example, a dielectric or insulating layer on the surface of a tag substrate (e.g., inlay 222 or strap substrate 254) may serve as the dielectric in capacitors 436/438. Metallic or conductive layers positioned on both sides of the dielectric layer (i.e., between the dielectric layer and the IC and between the dielectric layer and the tag substrate) may then serve as terminals of the capacitors 436/438. The conductive layers may include IC contacts (e.g., IC contacts 432/433), antenna segments (e.g., antenna segments 226/228), or any other suitable conductive layers.

[0043] Circuit 424 includes a rectifier and PMU (Power Management Unit) 441 that harvests energy from the RF signal incident on antenna segments 226/228 to power the circuits of IC 424 during either or both reader-to-tag (R->T) and tag-to-reader (T- R) intervals. Rectifier and PMU 441 may be implemented in any way known in the art, and may include one or more components configured to convert an alternating-current (AC) or time-varying signal into a direct-current (DC) or substantially time-invariant signal.

[0044] Circuit 424 also includes a demodulator 442, a processing block 444, a memory 450, and a modulator 446. Demodulator 442 demodulates the RF signal received via IC contacts 432/433, and may be implemented in any suitable way, for example using a slicer, an amplifier, and other similar components. Processing block 444 receives the output from demodulator 442, performs operations such as command decoding, memory interfacing, and other related operations, and may generate an output signal for transmission. Processing block 444 may be implemented in any suitable way, for example by combinations of one or more of a processor, memory, decoder, encoder, and other similar components. Memory 450 stores data 452, and may be at least partly implemented as permanent or semi-permanent memory such as nonvolatile memory (NVM), EEPROM, ROM, or other memory types configured to retain data 452 even when circuit 424 does not have power. Processing block 444 may be configured to read data from and/or write data to memory 450.

[0045] Modulator 446 generates a modulated signal from the output signal generated by processing block 444. In one embodiment, modulator 446 generates the modulated signal by driving the load presented by antenna segment(s) coupled to IC contacts 432/433 to form a backscatter signal as described above. In another embodiment, modulator 446 includes and/or uses a transmitter to generate and transmit the modulated signal via antenna segment(s) coupled to IC contacts 432/433. Modulator 446 may be implemented in any suitable way, for example using a switch, driver, amplifier, and other similar components. Demodulator 442 and modulator 446 may be separate components, combined in a single transceiver circuit, and/or part of processing block 444.

[0046] In some embodiments, particularly in those with more than one antenna port, circuit 424 may contain multiple demodulators, rectifiers, PMUs, modulators, processing blocks, and/or memories.

[0047] FIG. 5 A shows version 524- A of components of circuit 424 of FIG. 4, further modified to emphasize a signal operation during a R- T interval (e.g., time interval 312 of FIG. 3). During the R- T interval, demodulator 442 demodulates an RF signal received from IC contacts 432/433. The demodulated signal is provided to processing block 444 as C_IN, which in some embodiments may include a received stream of symbols. Rectifier and PMU 441 may be active, for example harvesting power from an incident RF waveform and providing power to demodulator 442, processing block 444, and other circuit components. During the R- T interval, modulator 446 is not actively modulating a signal, and in fact may be decoupled from the RF signal. For example, signal routing section 435 may be configured to decouple modulator 446 from the RF signal, or an impedance of modulator 446 may be adjusted to decouple it from the RF signal.

[0048] FIG. 5B shows version 524-B of components of circuit 424 of FIG. 4, further modified to emphasize a signal operation during a T->R interval (e.g., time interval 326 of FIG. 3). During the T~>R interval, processing block 444 outputs a signal C OUT, which may include a stream of symbols for transmission. Modulator 446 then generates a modulated signal from C OUT and sends the modulated signal via antenna segment(s) coupled to IC contacts 432/433, as described above. During the T- R interval, rectifier and PMU 441 may be active, while demodulator 442 may not be actively demodulating a signal. In some embodiments, demodulator 442 may be decoupled from the RF signal during the T~>R interval. For example, signal routing section 435 may be configured to decouple demodulator 442 from the RF signal, or an impedance of demodulator 442 may be adjusted to decouple it from the RF signal.

[0049] In typical embodiments, demodulator 442 and modulator 446 are operable to demodulate and modulate signals according to a protocol, such as the Gen2 Protocol mentioned above. In embodiments where circuit 424 includes multiple demodulators modulators, and/or processing blocks, each may be configured to support different protocols or different sets of protocols. A protocol specifies, in part, symbol encodings, and may include a set of modulations, rates, timings, or any other parameter associated with data communications. A protocol can be a variant of an internationally ratified protocol such as the Gen2 Protocol, for example including fewer or additional commands than the ratified protocol calls for, and so on. In some instances, additional commands may sometimes be called custom commands.

[0050] An RFID tag (or, equivalently, radio tag) can be assembled by electrically coupling an RFID IC (or, equivalent, radio IC) to an antenna on a tag substrate. The RFID IC includes at least two IC contacts, electrically isolated from each other. The antenna on the tag substrate has a portion including a gap between two antenna terminals, referred to as an antenna gap. During tag assembly, the RFID IC is aligned to and placed across the antenna gap such that different IC contacts each electrically contact a different antenna terminal.

[0051] FIG. 6A and 6B depict RFID IC alignment across an antenna gap. FIG. 6A shows an RFID IC 602 that is well-aligned across an antenna gap 610. Each of the IC contacts of the RFID IC 602 (IC contacts 604 and 606) electrically contacts only one of the antenna terminals (left antenna terminal 612 and right antenna terminal 614, respectively). FIG. 6B depicts an RFID IC 622 that is misaligned across an antenna gap 630. In FIG. 6B, the RFID IC 622 is misaligned (i.e., the IC 622 is right-shifted horizontally and at an angle), but each of the IC contacts (IC contacts 624 and 626) still electrically contact only one of the antenna terminals (left antenna terminal 632 and right antenna terminal 634, respectively). Further misalignment of the RFID IC 622 may cause, for example, the left IC contact 624 to electrically contact both the left antenna terminal 632 and the right antenna terminal 634, thereby shorting the two antenna terminals 632/634 and rendering the resultant RFID tag useless. While the misalignment depicted in FIG. 6B can be considered to be acceptable, the same misalignment in the case of a smaller antenna gap would be problematic. [0052] When RFID ICs shrink due to technology node advancements or streamlined designs, the possible physical separation between IC contacts also shrinks, resulting in the reduction of the maximum allowable size of the antenna gap. Antenna patterns are generally significantly larger than RFID ICs. Antenna fabrication techniques, designed to quickly and efficiently build antenna structures, may not be well suited to create small antenna gaps sized for RFID ICs. The smaller the allowable antenna gap, the more difficult it may be to create using current antenna fabrication techniques.

[0053] One solution to address increasingly smaller antenna gaps is to create the antenna gap after the antenna has been formed on the tag substrate. In this solution, the antenna structure is fabricated (using any suitable antenna fabrication technique) on the tag substrate without an antenna gap, but with an IC assembly region where the antenna gap is to be formed. Subsequently, the antenna gap is created within the IC assembly region by, for example, cutting an antenna portion with a laser. The gapcreation step may be integrated into the inlay assembly process, which is already serial in nature. For example, when a roll or spool of IC -less tag substrates (e.g., a “web”) is fed into the inlay assembly system, an in-line gap-creation tool can be used to form an antenna gap on a tag substrate before the IC is assembled or attached onto the tag substrate. In other examples, the gap-creation step could be integrated into the tag substrate manufacturing process.

[0054] FIG. 7A and 7B depict an IC-less tag substrate with an antenna and fiducial marks. In FIG. 7A, an antenna 702 is shown having a centered antenna gap 706 formed at an IC assembly region 704. The IC assembly region 704 is a region of the tag substrate where an RFID IC is to be placed or assembled. Accordingly, the IC assembly region 704 may include a portion of the antenna at which an antenna gap can be formed to receive an RFID IC. Fiducial mark(s) 708 may be configured to indicate the expected location of a centered antenna gap. The fiducial marks 708, in this case made of the same material as the antenna 702, aid an IC assembly apparatus in locating the antenna gap 706 for alignment and placement of an RFID IC. Once the IC assembly apparatus has located the antenna gap 706 and aligned the RFID IC appropriately across the antenna gap 706, it may cause the RFID IC to be electrically connected to the antenna 702, as described above. For example, the IC assembly apparatus may deposit an adhesive at the antenna gap 706, locate the antenna gap 706, align the RFID IC to the antenna gap 706, and then place the RFID IC such that it is attached to the tag substrate and respective IC contacts on the RFID IC are electrically connected to respective antenna terminals of the antenna gap 706. In certain situations, the IC assembly apparatus may use the fiducial marks 708 to locate the antenna gap 706, because the deposited adhesive may obscure the antenna gap 706 from the IC assembly apparatus.

[0055] If a fiducial mark and a corresponding antenna gap are created using the same process step at or around the same time, then the location of the fiducial mark with respect to the antenna gap may be relatively well known. Accordingly, the fiducial mark location indicates the antenna gap location with reasonable precision. However, if the fabrication of the fiducial mark and the corresponding antenna gap is performed using separate steps or at different times, then the relative location of each with respect to each other may not be well known, and the fiducial mark location may not indicate the antenna gap location with sufficient precision for RFID IC placement purposes. For example, suppose that the fiducial marks are created during antenna fabrication, whereas the antenna gap is formed afterward, during an inlay assembly process (e.g., an in-line laser-cutting scheme as described above). In this situation, process variations (e.g., offsets due to movement of the inlay web during the assembly process) may cause a mismatch between the expected antenna gap location indicated by the fiducial marks and the actual antenna gap location. FIG. 7B depicts such an example, where an antenna gap 716 is not centered at an IC assembly region 714 of antenna 712 (for example, due to an inlay offset during the gap formation process. In this example, an IC assembly apparatus using fiducial marks 718 for antenna gap location may fail to correctly locate antenna gap 716.

[0056] Fiducial mark fabrication typically occurs during antenna fabrication. However, as described above, antenna fabrication techniques may struggle to create small antenna gaps, which means that using antenna fabrication techniques to create fiducial marks and small antenna gaps at the same time may be relatively difficult. Alternatively, if the antenna gap is formed by a cutting process (e.g., via a laser), the same process may be used to cut at least part of the fiducial marks. In one embodiment, the same cut used to form the antenna gap may be extended to impinge on at least part of the fiducial marks. Extending the antenna gap cut to the fiducial mark(s) allows for the fiducial mark to indicate the actual location of an antenna gap formed by the same cut, regardless of whether the cut results in a centered antenna gap. As a result, an IC assembly apparatus can use the cut(s) on the fiducial mark(s) to locate the antenna gap and align an RFID IC for attachment accordingly.

[0057] FIG. 8 depicts an IC-less tag substrate with an antenna after a centered linear cut bisects an IC assembly region 804, forming an antenna gap 806, and also bisects a fiducial mark 808, according to embodiments. The linear (i.e., in a straight line) cut used to bisect the IC assembly region 804 to form the antenna gap 806 extends to the fiducial mark 808, such that the cut on the fiducial mark 808 indicates the actual location of the antenna gap 806 regardless of the cut’s alignment with the IC assembly region 804. Extending the cut to the fiducial mark 808 ensures that any misalignment of the antenna gap 806 (e.g., a horizontal and/or angular shift) with respect to a center of the IC assembly region 804 is reflected by the cut on the fiducial mark 808.

[0058] While FIG. 8 depicts a cut fully bisecting a fiducial mark, in some examples a cut may only pass through part of a fiducial mark. One such example is depicted in FIG. 9. FIG. 9 depicts an IC-less tag substrate with an antenna 902 after a shifted (i.e., not centered) linear cut bisects an IC assembly region 904 to form an antenna gap 906 and also at least partially bisects two fiducial marks 908 and 910, according to embodiments. In this example, an upper fiducial mark 908 is fully bisected, while a lower fiducial mark 910 is only partially cut. Despite the partial cut of the lower fiducial mark 910, the fiducial mark cuts may still be used to indicate the location of the antenna gap 906 formed by the shifted linear cut. Moreover, the availability of two separated fiducial mark cuts may facilitate RFID IC alignment to the antenna gap. For example, if one fiducial mark cut is obscured, the other fiducial mark cut may still be visible. As another example, cuts on two or more fiducial marks may enable an IC assembly apparatus to more precisely locate the antenna gap, because more than a single point of reference is available.

[0059] Extending an antenna gap cut to one or more nearby fiducial marks provides an indication of any lateral and/or angular shift of the antenna gap with respect to a desired location (e.g., the center of the IC assembly region). More specifically, a position of the cut on the fiducial mark(s) can indicate a location of the antenna gap, and an (angular) orientation of the cut on the fiducial mark(s) can indicate an angular orientation of the antenna gap. An example of angular orientation indication is provided by FIG. 10. FIG. 10 depicts an IC-less tag substrate with an antenna 1002 after an angled linear cut bisects an IC assembly region 1004 and two fiducial marks 1008, according to embodiments. The angled linear cut bisects the IC assembly region 1004 to form an antenna gap 1006, but is somewhat rotated with respect to a transverse axis of the tag substrate, indicated by a dashed line, resulting in antenna gap 1006 being nonorthogonal with respect to the transverse axis. The angled linear cut also extends to the fiducial marks 1008, resulting in fiducial mark cuts that are angled to the same degree as the antenna gap. An IC assembly apparatus may thereafter use the angled cuts on the fiducial marks 1008 to both locate the antenna gap 1006 and determine the antenna gap’s angular orientation.

[0060] The examples provided by FIGs. 8, 9, and 10 involve using a single linear cut to form an antenna gap and cut at least part of one or more fiducial marks. The cut(s) on the fiducial mark(s) can be used as reference points for an IC assembly apparatus to thereafter align an RFID IC to and across the antenna gap for subsequent attachment and electrical coupling to the antenna.

[0061] In some examples, fiducial mark cuts and antenna gaps may not be formed using the same cut. FIG. 11 depicts different cutting schemes for fiducial mark cuts and antenna gaps, according to embodiments. In a first cutting scheme 1100, a first cut 1102 is used to form an antenna gap at an IC assembly region 1104 while a second cut 1106 is made on a fiducial mark 1108. The first and second cuts 1102 and 1106 are collinear but separated by an offset distance A in a transverse direction. In a second cutting scheme 1110, a first cut 1112 is used to form an antenna gap at an IC assembly region 1114 while a second cut 1116 is made on a fiducial mark 1108. The first and second cuts 1112 and 1116 are separated by an offset distance B in the transverse direction. However, the first and second cuts 1112 and 1116 are not collinear. Instead, their centers are separated by an offset distance of C in a longitudinal direction.

[0062] When an antenna gap cut and a cut on a fiducial mark are offset as depicted in scheme 1110, the fiducial mark may need to be lengthened to accommodate the offset. For example, note that fiducial mark 1118 is substantially longer (in a longitudinal direction) than fiducial mark 1108. In some instances, the fiducial mark may instead be moved or offset during fabrication such that its location corresponds to where the offset cut would occur. [0063] Aligning an RFID IC to an antenna gap based on a fiducial mark cut made as depicted in scheme 1100 may be similar to aligning based on the fiducial mark cuts made as depicted in FIGs 8-10, because the fiducial mark cut, despite being offset, may remain collinear to the antenna gap. Aligning an RFID IC to an antenna gap based on a longitudinally offset fiducial mark cut as depicted in scheme 1010 must account for the offset distance C, but otherwise may be similar to aligning based on fiducial mark cuts collinear to the antenna gap.

[0064] In some examples, additional cuts in the antenna and/or fiducial marks may be used to provide additional reference points for IC alignment. FIG. 12 depicts different patterns for forming additional cuts in an antenna, according to embodiments. A first pattern 1200, a second pattern 1210, or a third pattern 1220 can be used to cut an IC assembly region or an antenna portion to provide more reference points for aligning an RFID IC across an antenna gap. For example, the first pattern 1200 includes a central cut and two additional cuts that flank the central cut. The central cut forms an antenna gap and may be extended to cut one or more fiducial marks (not depicted). The additional cuts may form additional reference points near the antenna gap. The second and third patterns 1210 and 1220 are similar to the first pattern 1200 in terms of defining a central cut for forming an antenna gap (and potentially cutting other fiducial marks) and additional cuts in the antenna portion for additional reference points. In some examples, the additional reference points can be used, alone or in combination with, fiducial mark cuts to place and align an RFID IC with respect to the antenna gap. Different patterns besides those depicted in FIG. 12 are possible, such as patterns which only include cuts on one side of the antenna gap, or patterns that include additional cuts that are extended to cut one or more fiducial marks. For example, cuts may be made to other portions of the antenna farther away from the IC assembly region, and those cuts may provide additional reference points for IC alignment and placement. In some situations, the antenna cuts may be sufficient to guide IC alignment and placement without needing fiducial mark cuts.

[0065] In FIGs. 11 and 12, the multiple cuts may be made by the same cutting tool or different cutting tools. In the former case, the cuts are likely serial in nature, which may require that the cutting tool be adjusted between performing different cuts. In the latter case, the tools may be prepositioned to perform the cuts simultaneously or serially. The cuts may be formed using any suitable technique and any suitable cutting tool. Such examples can include laser-cutting, use of a saw blade, use of a grinding wheel, or otherwise.

[0066] FIG. 13 illustrates a flow diagram of a method 1300 for assembling an RFID or radio tag, according to embodiments. The method 1300 can be used to assemble an radio tag, employing alignment techniques described herein.

[0067] At step 1302, the method 1300 can include receiving a tag substrate. The tag substrate can include a planar mounting material, a planar antenna that is formed on the mounting material and that has an IC assembly region, and at least a first fiducial mark formed on the mounting material and proximal to (i.e., near) the IC assembly region of the planar antenna. An example of such tag substrates is partially illustrated by FIG. 7A, except without the centered antenna gap. In FIG. 7A the planar mounting material is also not explicitly shown. In some examples, the tag substrate may include more than one fiducial mark formed on the mounting material.

[0068] At step 1304, a cut at the IC assembly region to form an antenna gap and a cut on the first fiducial mark may be formed. The cut at the IC assembly region may be to an antenna portion to form the antenna gap. The cut on the first fiducial mark may bisect the first fiducial mark, or many only partially cut the first fiducial mark. If the tag substrate includes more than one fiducial mark, any of the plurality of fiducial marks may additionally be cut, similarly to the first fiducial mark. The cut on the first fiducial mark provides an indication of the orientation and location of the antenna gap. For example, the orientation of the cut on the first fiducial mark can provide an indication of the orientation of the antenna gap (e.g., having the same or similar orientation) and the position of the cut on the first fiducial mark can further provide an indication of the location of the antenna gap. The cut on the IC assembly region can bisect the IC assembly region to form an antenna gap. The cut on the first fiducial mark may preferably be collinear with the formed antenna gap, however, as described above, the cut on the fiducial mark is not necessarily collinear with the antenna gap. In such examples, an offset of the fiducial marks may additionally be used to determine the location of the antenna gap. As described above, one or more cutting tools can be used to perform the cuts at the IC assembly region and on the first fiducial mark. The cuts at the IC assembly region and on the first fiducial mark may be distinct cuts, but they may be performed at significantly the same step during the radio tag assembly process. Further, in some examples such as those described by FIG. 12, additional cuts can be made on one or more of the IC assembly region, the first fiducial mark, or other fiducial marks.

[0069] At step 1306, an adhesive may be applied to the antenna gap for attaching an RFID IC to the antenna. The adhesive may at least partially obscure the antenna gap, but may not affect the visibility of the cut on the first fiducial mark, cuts on other fiducial marks, or any additional cuts used for alignment.

[0070] At step 1308, a radio IC can be aligned across the formed antenna gap using at least the cut on the first fiducial mark. The cut on the first fiducial mark can be used to determine an orientation and a position of the radio IC such that it is aligned across the antenna gap. For example, an IC alignment mechanism of an IC assembly machine may be optically aligned with the cut on the first fiducial mark. The IC assembly machine may be configured such that when the alignment mechanism is aligned with the cut on the first fiducial mark, the radio IC is relatively well-aligned with the antenna gap.

[0071] At step 1310, the radio IC may be attached to the planar antenna such that the radio IC bridges the antenna gap. The well-aligned radio IC may be attached to the planar antenna such that a first IC contact or connection point on the radio IC electrically connects to the planar antenna solely at a first antenna terminal on one side of the antenna gap and a second IC contact or connection point on the radio IC electrically connects to the planar antenna solely at a second antenna terminal on the other side of the antenna gap. An example an attached, well-aligned radio IC is depicted by FIG. 6A.

[0072] According to some examples, a method for assembling a radio tag includes receiving a tag substrate. The tag substrate may comprise a planar mounting material, a planar antenna formed on the mounting material and having an integrated circuit assembly region, and a first fiducial mark formed on the mounting material and proximal to the planar antenna. The method may include forming cuts on both the IC assembly and the first fiducial mark, wherein the cut on the IC assembly region bisects the IC assembly region to form an antenna gap. The method may also include applying an adhesive to the antenna gap that at least partially obscures the antenna gap but does not obscure the cut on the first fiducial mark. The method may further include optically aligning a radio IC across the antenna gap using at least the cut on the first fiducial mark and attaching the aligned radio IC to the planar antenna using the adhesive such that the radio IC bridges the antenna gap.

[0073] According to other examples, attaching the aligned radio IC to the antenna such that the radio IC bridges the antenna gap comprises attaching the aligned radio IC such that a first connection point on the radio IC electrically connects to the planar antenna solely on one side of the antenna gap, and a second connection point on the radio IC electrically connects to the planar antenna solely on the other side of the antenna gap. The antenna gap and the cut on the first fiducial mark may be collinear. The method may additionally comprise forming the cuts on the IC assembly region and the first fiducial mark in the same step. The method may further comprise forming the cuts such that at least one of an orientation and a position of the cut on the first fiducial mark indicate a location of the antenna gap. The cuts may be formed using a laser. The cuts may be formed during an inlay assembly process. Forming the cuts may comprise forming a cut on a second fiducial mark and optically aligning the radio IC may comprise optically aligning the radio IC using at least the cut on the first fiducial mark and the cut on the second fiducial mark. Aligning the radio IC across the antenna gap may comprise determining at least one of an orientation and a position of the radio IC with respect to the antenna gap based on at least the cut on the first fiducial mark.

[0074] According to some examples, a radio tag includes a tag substrate comprising a planar mounting material, a planar antenna formed on the mounting material having an antenna gap formed by cutting an IC assembly region of the planar antenna to bisect the IC assembly region, and a first fiducial mark having a cut used to optically align a radio IC across the antenna gap, and a radio IC attached to the planar antenna using an adhesive that obscures the antenna gap but does not obscure the cut on the first fiducial mark, such that the radio IC bridges the antenna gap.

[0075] According to other examples, the radio IC is attached to the planar antenna such that a first connection point on the radio IC electrically connects to the planar antenna solely on one side of the antenna gap, and a second connection point on the radio IC electrically connects to the planar antenna solely on the other side of the antenna gap. The antenna gap and the cut on the first fiducial mark may be collinear. The cuts on the IC assembly region and the first fiducial mark may be formed during the same step of a radio tag assembly process. The cuts may be such that at least one of an orientation and a position of the cut on the first fiducial mark indicate a location of the antenna gap. The cuts may be formed using a laser. The cuts may have been formed during an inlay assembly process. The radio IC may further include a second fiducial mark having a cut on a second fiducial mark and the radio IC may be optically aligned using at least the cut on the first fiducial mark and the cut on the second fiducial mark. The radio IC may be aligned across the antenna gap may by determining at least one of an orientation and a position of the radio IC with respect to the antenna gap based on at least the cut on the first fiducial mark

[0076] As mentioned previously, embodiments are directed to assembling radio tags. Embodiments additionally include programs, and methods of operation of the programs. A program is generally defined as a group of steps or operations leading to a desired result, due to the nature of the elements in the steps and their sequence. A program is usually advantageously implemented as a sequence of steps or operations for a processor but may be implemented in other processing elements such as FPGAs, DSPs, or other devices as described above.

[0077] Performing the steps, instructions, or operations of a program requires manipulating physical quantities. Usually, though not necessarily, these quantities may be transferred, combined, compared, and otherwise manipulated or processed according to the steps or instructions, and they may also be stored in a computer- readable medium. These quantities include, for example, electrical, magnetic, and electromagnetic charges or particles, states of matter, and in the more general case can include the states of any physical devices or elements. Information represented by the states of these quantities may be referred-to as bits, data bits, samples, values, symbols, characters, terms, numbers, or the like. However, these and similar terms are associated with and merely convenient labels applied to the appropriate physical quantities, individually or in groups.

[0078] Embodiments furthermore include storage media. Such media, individually or in combination with others, have stored thereon instructions, data, keys, signatures, and other data of a program made according to the embodiments. A storage medium according to embodiments is a computer-readable medium, such as a memory, and can be read by a processor of the type mentioned above. If a memory, it can be implemented in any of the ways and using any of the technologies described above. [0079] Even though it is said that a program may be stored in a computer-readable medium, it does not need to be a single memory, or even a single machine. Various portions, modules or features of it may reside in separate memories, or even separate machines. The separate machines may be connected directly, or through a network such as a local access network (LAN) or a global network such as the Internet.

[0080] Often, for the sake of convenience only, it is desirable to implement and describe a program as software. The software can be unitary or thought of in terms of various interconnected distinct software modules.

[0081] The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams and/or examples. Insofar as such block diagrams and/or examples contain one or more functions and/or aspects, each function and/or aspect within such block diagrams or examples may be implemented individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented employing integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g. as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and/or firmware would be well within the skill of one of skill in the art in light of this disclosure.

[0082] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, configurations, tags, RFICs, readers, systems, and the like, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0083] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0084] In general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). If a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations).

[0085] Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). Any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

[0086] For any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. All language such as “up to,” “at least,” “greater than,” “less than,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

Claims

CLAIMS WE CLAIM:

1. A method for assembling a radio tag, the method comprising: receiving a tag substrate comprising: a planar mounting material, a planar antenna formed on the mounting material and having an integrated circuit (IC) assembly region, and a first fiducial mark formed on the mounting material and proximal to the planar antenna; forming cuts on both the IC assembly region and the first fiducial mark, wherein the cut on the IC assembly region bisects the IC assembly region to form an antenna gap; applying an adhesive to the antenna gap that at least partially obscures the antenna gap but does not obscure the cut on the first fiducial mark; optically aligning a radio IC across the antenna gap using at least the cut on the first fiducial mark; and attaching the aligned radio IC to the planar antenna using the adhesive such that the radio IC bridges the antenna gap.

2. The method of claim 1, wherein attaching the aligned radio IC to the planar antenna such that the radio IC bridges the antenna gap comprises attaching the aligned radio IC such that: a first connection point on the radio IC electrically connects to the planar antenna solely on one side of the antenna gap, and a second connection point on the radio IC electrically connects to the planar antenna solely on the other side of the antenna gap.

3. The method of claim 1, wherein the antenna gap and the cut on the first fiducial mark are collinear.

4. The method of claim 1, further comprising forming the cuts on the IC assembly region and the first fiducial mark in the same step.

5. The method of claim 1, further comprising forming the cuts such that at least one of an orientation and a position of the cut on the first fiducial mark indicate a location of the antenna gap.

6. The method of claim 1, further comprising forming the cuts using a laser.

7. The method of claim 1, further comprising forming the cuts during an inlay assembly process.

8. The method of claim 1, wherein: forming the cuts comprises forming a cut on a second fiducial mark; and optically aligning the radio IC comprises optically aligning the radio IC using at least the cut on the first fiducial mark and the cut on the second fiducial mark.

9. The method of claim 1, wherein aligning the radio IC across the antenna gap comprises determining at least one of an orientation and a position of the radio IC with respect to the antenna gap based on at least the cut on the first fiducial mark.

10. A radio tag assembled according to any one of claims 1-9.