Electronic tag

Abstract

A capacitively coupled radio frequency identification (RFID) tag and a method for reading the tag are disclosed. The tag includes a semiconductor substrate having a first plane and a second plane disposed away from the first plane. Metal pads are formed on the first plane of the semiconductor substrate. Circuitry is formed on the semiconductor substrate and electrically connected to the metal pads and the second plane of the semiconductor substrate. The circuitry is configured to respond to an RF input signal by providing a data signal, the data signal being encoded by changing the impedance between the metal pads and the second plane of the semiconductor substrate.

Description

Technical Field

[0001] This invention relates to a capacitively coupled RFID (Radio Frequency Identification) tag and its operation method. Background Technology

[0002] Capacitively coupled tags (CC-tags or CCTs) offer enhanced security while providing authenticity and tracking capabilities. This technology is widely used for tracking artifacts where security and authenticity are paramount. However, the potential number of applications increases as CC-tags can be reduced in size and their efficiency improved.

[0003] Other types of RFID tags exist that may include an antenna for receiving RF (radio frequency) signals from a reader to power the device and use the same antenna to respond to the signal. However, using such an antenna increases the size of the device and the complexity of manufacturing, thus limiting the application of the device. Furthermore, such an antenna can introduce a point of failure that makes the device less robust. CC-tags do not use an antenna; instead, they interact with the RF signal provided by the reader by changing their impedance. This affects the electric field generated by the reader, which in turn is detected by the reader. When this impedance change is modulated, this modulation can be decoded to provide data (such as the CC-tag's identifier).

[0004] The document "0.075x0.075mm" 2 The paper "Ultra-Small 7.5μm Ultra-Thin RFID-Chip Mounting Technology" (Hideyuki Noda and Mitsuo Usami, 978-14244-2231-9 / 08, IEEE 2008 Conference on Electronic Components and Technology, pp. 366-370) describes the fabrication of a small RFID chip including an antenna. However, the fabrication of such RFID chips, especially on a large scale, presents technical difficulties that reduce yield and increase failure rate during the manufacturing process.

[0005] The document "Powder RFID Chip Technology" (Mitsuo Usami, Hitachi, Ltd., 978-1-4244-2342-2 / 08, IEEE 2008, pp. 1220-1223) describes another type of small RFID tag and its manufacturing method, which also requires placing an antenna structure on the RFID chip. This limits the size of the tag to a lower limit.

[0006] The document “26.6–A0.05x0.05mm2 RFID Chip with Easily Scaled-Down ID-Memory” (Mitsuo Usami, Hisao Tanabe, Akira Sato, Isao Sakama, Yukio Maki, Toshiaki Iwamatsu, Takashi Ipposhi, Yasuo Inoue, Hitachi, ISSCC 2007 / SESSION 26 / NON-VOLATILEMEMORIES / 26.6, 1-4244-0852-0 / 07, IEEE 2007, pp. 482-483) describes an RFID chip with a unique IP address that uses double-sided electrodes.

[0007] Another requirement is that the RFID tag can be read in the presence of other RFID tags. This can be particularly difficult for very small RFID tags, as these tags can be embedded in many separate items stacked or placed close together.

[0008] Therefore, a capacitively coupled tag and operating method is needed to overcome these problems. Summary of the Invention

[0009] This invention provides a capacitively coupled RFID tag (CC-tag or RFID tag) that is thin (e.g., 100 μm, 50 μm, or less) and formed on a semiconductor substrate, such as silicon, with one surface covered by a metal layer (e.g., gold on aluminum) and the other opposite surface being an exposed semiconductor surface. These surfaces together act as a tunable impedance. Circuitry or a chip (such as an integrated circuit IC) on or within the semiconductor substrate controls the device and alters its electrical properties as seen from an external reader (electrically), which typically uses electrodes to apply an electric field to the CC-tag. The CC-tag is powered by the externally applied RF electric field and responds to the presence of the electric field by changing its electrical properties (particularly its impedance). The CC-tag is capacitively coupled to the reader, and the integrated circuit modulates its electrical properties to encode a data signal, which is decoded by the reader. The electrical properties are altered by changing the impedance between the metal layer and the opposite semiconductor layer.

[0010] When one or more such CC-tags or a stack of such CC-tags are placed within an electric field generated by the reader, only one CC-tag is configured to respond. In an exemplary embodiment, the remaining CC-tags can have their impedance reduced (e.g., statically) by, for example, by applying a short circuit between a metal surface and an opposing semiconductor surface, so that each CC-tag can respond sequentially and in isolation and provide its output signal by modulating the RF input signal.

[0011] The present invention also provides a method for manufacturing capacitively coupled RFID tags, namely, providing a semiconductor substrate (e.g., silicon) having opposing planes, applying a metal layer on one of the planes, and forming the circuitry described herein (e.g., CMOS circuitry) on or within the other plane (e.g., using photolithography). Preferably, the thickness (i.e., the distance between opposing planes) is equal to or less than 50 μm (or 25 μm, 100 μm, or 150 μm). The substrate can be square, rectangular, or other shapes. Preferably, the width and / or length of the substrate and the final device are between 50 and 700 μm.

[0012] Applications of these concepts include, but are not limited to, banknotes, visas, stamps, official documents, holograms, aluminum foil, any kind of cigarettes and tobacco products (such as standard cigarettes and e-cigarettes), bottles, labels, food, food packaging, tablets and other pharmaceutical products (including their coatings and packaging), and other types of packaging that require this small and micron-thickness solution. CC-labels can be embedded or adhered to such items.

[0013] In the context described above, according to the first aspect, a capacitively coupled radio frequency identification (RFID) tag (e.g., a CC-tag) is provided, comprising:

[0014] A semiconductor substrate having a first plane and a second plane away from the first plane;

[0015] Metal pads are formed on the first plane of the semiconductor substrate;

[0016] A circuit, formed on a semiconductor substrate and electrically connected to a metal pad and a second plane of the semiconductor substrate, is configured to respond to an RF input signal by providing a data signal encoded by changing the impedance between the metal pad and the second plane of the semiconductor substrate. Providing a metal pad on one side and a semiconductor surface on the other reduces manufacturing complexity (e.g., compared to a CC-tag that might have metal pads on each side) because the semiconductor surface is provided by the substrate, while allowing the opposing surfaces to provide capacitance, which can be changed by altering the impedance of the means between the surfaces. For example, the plane can be flat or curved (e.g., to accommodate the shape of the object to which the label is attached) without affecting the label's functionality.

[0017] Preferably, the data signal can be encoded by modulating the RF input signal by changing the impedance between the metal pad and the second plane of the semiconductor substrate. This allows the RF input signal to be used both to power the device and to be decoded by the reader.

[0018] Preferably, the RF input signal can be provided by an external reader.

[0019] Advantageously, the circuit is further configured to be powered by an RF input signal.

[0020] Advantageously, the circuit can be further configured to decode a signal encoded within an RF input signal, and wherein a data signal is provided in response to the decoded signal. The circuit may optionally include a small amount of power storage (e.g., a capacitor) to store the power generated by the RF input signal for a very short time.

[0021] Optionally, the circuit modulates the signal by changing the frequency, amplitude and / or phase or any other electrical characteristics of the RF input signal.

[0022] Alternatively, the circuit can be formed on or embedded in a second plane of a semiconductor substrate.

[0023] Alternatively, the circuit can be configured to change the impedance between the metal pad and the second plane of the semiconductor substrate by applying a short circuit between the metal pad and the second plane of the semiconductor substrate.

[0024] Optionally, the distance between the outer surface of the metal pad and the second plane of the semiconductor substrate is equal to or less than 50 μm. This can be described as the thickness of the CC-tag. For example, alternatively, this thickness can be less than or equal to 10 μm, 25 μm, 100 μm, or 150 μm. For example, the CC-tag can have a substantially square or rectangular cross-section.

[0025] Optionally, the circuit can be further configured to detect the presence of one or more other capacitively coupled RFID tags (e.g., of the same type) and, in response, stop providing data signals. This prevents signal collisions and allows multiple CC-tags to be read sequentially, rather than having only one CC-tag within the reader's range at a time.

[0026] Alternatively, the circuit can be configured to stop providing data signals by applying a short circuit between the metal pads and the second plane of the semiconductor substrate. This effectively makes the "disconnected" (multiple) CC-tags (electrically) invisible to the reader.

[0027] Optionally, the circuit can be configured to stop providing data signals until one or more other capacitively coupled RFID tags have provided their data signals.

[0028] Optionally, the circuit may be further configured to stop providing data signals in accordance with an anti-collision (i.e., to prevent their data signals from colliding) protocol.

[0029] Alternatively, the anti-collision protocol can be based on communication between one or more capacitively coupled RFID tags, according to the following:

[0030] Based on a predetermined response sequence, negotiated responses between one or more capacitively coupled RFID tags, or a random number generator. This anti-collision protocol may not rely on direct communication between CC-tags, but such communication can pass through the reader, or it may not rely on communication at all.

[0031] Alternatively, the first plane can be parallel to the second plane. Other configurations can also be used as long as these planes can generate capacitance.

[0032] Optionally, the capacitively coupled RFID tag is flexible. This can include a bending radius comparable to the width or length of the CC-tag. Therefore, the CC-tag can be embedded or attached to flexible items with a lower risk of damage.

[0033] Optionally, the capacitively coupled RFID tag may also include a metal plate. This couples the reader's electrodes to the side of the tag that is not facing the reader. Therefore, this avoids the need to place the reader electrodes on the opposite side of the tag.

[0034] Optionally, the capacitively coupled RFID tag may also include an insulator bonded between the tag and the metal plate.

[0035] Alternatively, the insulator can be bonded to the metal pads of the label. Bonding can be achieved using adhesives or other suitable methods.

[0036] Alternatively, the insulator may be bonded to a second plane of the semiconductor substrate.

[0037] Alternatively, the metal sheet can be bent. Therefore, the metal sheet can be adapted to objects, such as cylindrical or spherical objects.

[0038] Optionally, the metal plate may extend beyond at least one edge of the metal pads and / or the semiconductor substrate.

[0039] According to a second aspect, an article is provided having a capacitively coupled RFID tag according to any of the preceding claims embedded therein.

[0040] Optionally, the surface of the item is parallel or substantially parallel to the first plane of the capacitively coupled RFID tag. This is useful for flat, planar objects and / or flexible objects.

[0041] Alternatively, the items can be made of paper or plastic materials, and can be banknotes, passports, ID cards, tax stamps, cigarettes, e-cigarettes, labels, tablets (such as medicines), beverage capsules, coffee capsules, tea capsules, and / or legal documents.

[0042] According to a third aspect, a method for communicating with multiple capacitively coupled RFID tags is provided, the method comprising the following steps:

[0043] The radio frequency (RF) input signal is applied to the plurality of capacitively coupled RFID tags;

[0044] One of the plurality of capacitively coupled RFID tags responds to the applied RF input by changing its impedance, and the changed impedance encodes the data signal.

[0045] The change in the RF input signal caused by altering the impedance of one of the plurality of capacitively coupled RFID tags is detected, and the change is encoded into the data signal;

[0046] The data signal is decoded based on the changes in the RF input signal;

[0047] One of the capacitively coupled RFID tags changes its impedance, while one of the plurality of capacitively coupled RFID tags that does not respond decreases its impedance. Other methods for reading the aforementioned CC-tags can also be used.

[0048] Optionally, the change in the RF input signal can be a change in frequency, amplitude, and / or phase.

[0049] Preferably, the method may further include the step of using an anti-collision protocol to determine which of a plurality of capacitively coupled RFID tags responds to radio frequency by changing its impedance.

[0050] Optionally, multiple capacitively coupled RFID tags can be stacked on top of each other or placed close to each other in other ways.

[0051] According to a fourth aspect, a computer program is provided, including program instructions that, when executed on a computer, cause the computer to perform the method described above.

[0052] According to the fifth aspect, a computer-readable medium having the computer program described above is provided.

[0053] According to the sixth aspect, a system is provided, comprising:

[0054] Any one of the above-mentioned capacitively coupled RFID tags; and

[0055] The reader, which includes an RF signal generator and a decoder, is configured to decode data signals.

[0056] Optionally, the reader may also include:

[0057] A first electrode is configured to be aligned with the metal pads and / or semiconductor substrate of the label; and

[0058] The second electrode is configured to be partially aligned with a metal plate that extends beyond at least one edge of a metal pad and / or semiconductor substrate. For example, the system may include a label having a metal plate that extends into or beyond the substrate or metal pad.

[0059] Alternatively, the metal plate can be formed from the metal packaging of a box, can, coffee capsule, tea capsule, or beverage capsule. Therefore, the manufacture of the device can be simplified, and the label can be used and applied more effectively to metal articles.

[0060] Optionally, the first electrode and / or the second electrode can be curved. Thus, the electrodes can be adapted to cylindrical or spherical objects (e.g., cigarettes or electronic cigarettes).

[0061] The above method can be implemented as a computer program, which includes program instructions for operating the computer. This computer program can be stored on a computer-readable medium.

[0062] A computer system (e.g., implemented within an integrated circuit) may include one or more processors (e.g., local, virtual, or cloud-based processors), such as a central processing unit (CPU), and / or a single or group of graphics processing units (GPUs). The processors may execute logic in the form of software programs. The computer system may include memory, comprising volatile and non-volatile storage media. Computer-readable media may be included to store logic or program instructions. Different parts of the system may be connected using a network (e.g., wireless and wired networks). The computer system may include one or more interfaces. The computer system may contain a suitable operating system, such as UNIX, Windows (RTM), or Linux.

[0063] It should be noted that any of the above features can be used in any particular aspect or embodiment of the present invention. Attached Figure Description

[0064] This invention can be implemented in many ways, and embodiments will now be described by way of example only, with reference to the accompanying drawings, in which:

[0065] Figure 1 A schematic diagram of a capacitively coupled RFID tag being read by a reader is shown.

[0066] Figure 2 This shows multiple items read by the reader. Figure 1 A schematic diagram of a capacitively coupled RFID tag;

[0067] Figure 3 A schematic diagram of another capacitively coupled RFID tag being read by a reader is shown;

[0068] Figure 4 A schematic diagram of another capacitively coupled RFID tag being read by a reader is shown;

[0069] Figure 5 A schematic diagram of the system is shown, which includes components applied to cigarettes or electronic cigarettes (or other objects). Figures 1 to 4 Either the capacitively coupled RFID tag or the reader in the device;

[0070] Figure 6a It is shown that when applied to cigarettes or e-cigarettes Figure 5 A cross-sectional view of a capacitively coupled RFID tag;

[0071] Figure 6b It shows Figure 6a A schematic diagram of a cigarette or electronic cigarette and reader electrodes; and

[0072] Figure 7 This diagram shows multiple additional capacitively coupled RFID tags (each attached to an item) being read by a reader.

[0073] It should be noted that the accompanying drawings are shown for simplicity and are not necessarily drawn to scale. The same features have the same reference numerals. Detailed Implementation

[0074] According to an example implementation, a capacitively coupled tag (CC-tag) is a radio frequency identification (RFID) system based on a single integrated circuit (IC). In common applications, an integrated circuit is a single-crystal silicon wafer whose one side is functionalized through various steps to integrate electronic components, such as, but not limited to, resistors, capacitors, diodes, transistors, etc., connected by metal layers.

[0075] Because these components are small in size, electrical connections to the integrated circuit are provided using several "pads" or metal layers that are large enough to connect to smaller wires or probes. These "pads" are typically placed on the functionalized side of the integrated circuit.

[0076] The back side of an integrated circuit (IC) is typically connected to a ground reference and has no particular significance at the electronic level. In the CC-tag of this invention, a large metal pad is placed on the functionalized side of the IC, and a second pad is provided on the back side of the device. This structure allows the device to be freely positioned on the surface without any precise positioning or angular orientation, and the device functions regardless of which side of the surface the CC-tag is placed on. This important feature simplifies the deposition process and reduces associated costs.

[0077] ICs can be fabricated using CMOS (Complementary Metal-Oxide-Semiconductor) technology (i.e., silicon-based technology). Due to the simultaneous presence of n-type and p-type MOS transistors on the same silicon substrate, a well-known "latch-up" effect can occur. This is likely caused by parasitic thyristors inherent in CMOS structures, which can be triggered by unexpected voltage spikes, creating a short circuit between the positive and negative contacts of the device's power supply. This effect is typically reduced by placing additional ground contacts on the substrate. This effect is even stronger for CC-labeled devices due to the presence of radio frequency (RF) signals from the back-side pads (i.e., the semiconductor), which may be connected to the IC's dummy ground. To avoid this effect, additional ground contacts can be placed near the MOS transistors. Alternatively, other semiconductors such as gallium arsenide, graphene, germanium, and silicon carbide can also be used.

[0078] In this CC-labeled example, the back side of the integrated circuit (i.e., the ordinary semiconductor substrate) is used as a potential solder pad and is placed on a second large pad near the top (opposite side) of the functionalized surface. In this example, the structure takes the form of a thin plate (with a first surface and an opposite surface). The system includes an integrated circuit with a pad on top and a pad on the bottom (or vice versa depending on any particular orientation), which can be used as a capacitor plate in a specially developed reader.

[0079] The reader can communicate with the CC-tag via a modulated electric field (capacitive coupling) without requiring electrical continuity between the reader and the tag.

[0080] Standard RFID tags have an input stage consisting of an inductor and a tuning capacitor that act as an antenna, tuned at the transmission frequency to optimize signal transmission. In contrast, CC-tags present only a capacitor at the input stage. The capacitor exhibits short-circuit behavior at high frequencies; the visible cutoff frequency of this behavior depends on the capacitor's own value and the parasitic resistance of the circuit. This approach has a significant advantage because the coupling capacitor is required to be just "high enough" to exhibit short-circuit behavior without requiring precise tuning of the capacitor itself. This results in a significantly reduced dependence on process parameter fluctuations during the deposition step.

[0081] For the same reason, CC-tags can even operate at different frequencies simultaneously, and generally, the higher the frequency, the better. The solution shown in the attached diagram (described in more detail below) has several advantages.

[0082] - The label is extremely simple, inexpensive, and very robust to manufacture. It can be easily manufactured using standard integrated circuit technology.

[0083] It does not require special alignment on the item to be marked, which in turn reduces manufacturing complexity and cost.

[0084] - When the CC-tag is in the heap, it can also be read, at which point it executes the anti-collision protocol for the tag and the reader.

[0085] CC-labels can be thinned to below 50μm to form ultra-thin and flexible labels that can be encapsulated in a variety of applications, such as, but not limited to, banknotes, official and government documents, tax invoices, visas, holograms, and packaging for any goods, paper, etc.

[0086] Figure 1 A schematic diagram of a capacitively coupled tag 10 (CC-tag) powered and read by a tag reader 20 is shown. The tag reader 20 includes electrodes 30 that provide an electric field 70 by generating a radio frequency (RF) signal. This RF signal can be modulated and detected by the capacitively coupled tag 10. As shown in this figure, the upper or top surface 10 of the capacitively coupled tag 10 has metal electrodes 40. The opposite or bottom surface of the capacitively coupled tag 10 is exposed, forming a semiconductor electrode surface 50. Within or on the surface of the semiconductor substrate of the capacitively coupled tag 10 is a circuit (i.e., an integrated circuit) 60 (not shown in detail in this figure). The electric field 70 is indicated by arrows between the electrodes 30 of the reader 20. The metal can be aluminum, copper, gold, silver, or a combination of independent metal layers (such as gold on aluminum). The IC can be fabricated on or within the surface of the CC-tag 10 (i.e., the semiconductor pad surface) without metal pads. Preferably, these surfaces are parallel and planar.

[0087] Figure 2 Another schematic diagram shows multiple capacitively coupled tags 10, which are in the same form as... Figure 1 The same applies. Similarly, reader 20 applies an electric field between its electrodes 30 to read each capacitively coupled tag 10. The diagram does not show any items or substrates attached to each CC-tag 10 to simplify the illustration, but this would be true. Figure 7 An equivalent layout is shown, including the items to be tagged attached to each CC-tag 10 in the CC-tag stack. It should be noted that the CC-tags 10 do not need to be perfectly aligned for the reader to read them.

[0088] When there is more than one CC-tag 10 between the electrodes of the reader 30, all but one CC-tag 10 respond to the incident RF input signal by modulating the input signal (i.e., by changing their own impedance to provide a data signal). The remaining CC-tags optionally reduce their impedance, for example, by short-circuiting their pads (metal surface and semiconductor surface). This makes them electrically invisible to the reader. Once the first CC-tag provides its data signal, it stops modulating the input RF signal and short-circuits its own pad. Then another CC-tag responds to the input RF signal by modulating the input RF signal as described above. This process continues until all CC-tags have provided their data. Therefore, CC-tags can be stacked one on top of another without reducing signal strength.

[0089] Individual CC-tags can communicate with each other to determine which will respond to a signal. This can be achieved using an anti-collision algorithm that introduces random delays, resulting in different transmission times for each tag. Alternatively, no communication is required, and each CC-tag can respond to an input RF signal after a different (e.g., random) delay, which significantly reduces the risk that any two CC-tags will respond at the same time (the actual transmission time may be very short compared to the delay time).

[0090] For example, by using one or more transistors to change their state from "blocking" to "saturation" to act as an on / off switch, it is possible to short-circuit the pads.

[0091] Other alternative implementation schemes may be used. These alternative implementation schemes may include any one or more of the following alternatives or advantages.

[0092] • The CC-tag 10 can be embedded in ultra-thin structures or embedded in their surfaces (such as paper, banknotes, holograms, stamps, etc.) without requiring any antenna, alignment, or special positioning.

[0093] • The CC-tag 10 does not need to have metal contact with the reader. Radio frequency (RF) signals can be transmitted from the reader to the CC-tag 10, and can even pass through insulating layers, as long as these insulating layers are thin (less than 1 mm).

[0094] • When the reader is within reading range, the CC-tag 10 can draw power from the reader. The CC-tag 10 can respond by adjusting the impedance (on / off switch) between the top and bottom electrodes.

[0095] • The CC-label 10 does not operate at circuit resonance and does not have frequency offset issues, making it more robust to fluctuations in production parameters.

[0096] • CC-tag 10 can be read in the heap as long as the CC-tag is aligned in the heap, or it can be capacitively coupled using an additional metal layer placed on a thin structure.

[0097] • The CC-Tag 10 can be equipped with an anti-collision solution to prevent two or more tags from communicating with the reader simultaneously.

[0098] When CC-tag 10 is read from the heap, it can follow the following process:

[0099] It receives electrical energy and data from the reader within a certain period of time (charging time).

[0100] If the tag should respond, it can modulate its impedance to communicate with the reader.

[0101] If a tag should not respond, it can reduce its output impedance to a low level (on) to allow the reader signal to be passed to the tag that is expected to respond.

[0102] When the CC-tags 10 are read in the stack, they are electrically “connected in series” with each other. This means that the voltage applied to the stack is distributed according to the number of elements in the stack. The reader can provide adaptive voltage to provide sufficient voltage or power for each CC-tag 10 to operate. For example, this could involve increasing the applied electric field (such as voltage and / or power) to a level that can power all CC-tags. It should be noted that the CC-tags 10 can be placed between the reader electrodes in any orientation. For example, the first electrode can be up or down, and the second electrode can be down or up. Different CC-tags 10 placed in the stack can be positioned in any orientation, and the orientation can be different for CC-tags 10 within the same stack.

[0103] The preceding examples described CC-tag reading technology, in which a tag or series of tags is "clamped" or preferably tightly positioned between two reader electrodes (e.g., a portion of the reader). This approach is particularly suitable for items requiring marking, such as thin structures like paper, banknotes, etc. Figure 3 As shown), CC-label 10 is located on or within it.

[0104] In another example implementation, "one-sided" readout can be used. This example implementation avoids the need to place the reading electrode on either side of the article, thus allowing it to be used for larger or thicker objects. This can be achieved by adding an additional metal layer (such as a suitable conductor like aluminum, copper, silver, or gold) behind the CC-tag 10 on the article, as... Figure 4 As shown. Figure 4A CC-label positioned on the top of an item is shown, but a CC-label can also be positioned on the side or bottom of the item. The CC-label used in this example embodiment can be the same as or substantially similar to those previously described.

[0105] The metal layer extends or overlaps beyond the extent of the CC-tag 10 in at least one direction. The reader uses two electrodes. Electrode #1 is positioned on the CC-tag 10 (and a portion of the metal layer) on the object. Electrode #2 is positioned substantially away from the CC-tag 10, but on or aligned with another portion of the metal layer that is not below or aligned with the CC-tag 10. Therefore, the electrodes can be placed on the same side of the article, but capacitive coupling with the CC-tag 10 is permitted. In other words, the reader, CC-tag 10, and article are arranged in sequence with a first reader electrode, the CC-tag 10 (e.g., directly below the first electrode), a continuous metal layer, and the article to be tagged. A second reader electrode is adjacent to the first electrode, and the same metal layer exists between the second electrode and the article. In the example embodiment, as... Figure 4 As shown, the CC-tag 10 may be embedded or partially embedded in an insulating layer (e.g., a polymer or other dielectric) placed on and substantially covering the metal layer. The insulating layer (or a portion thereof) may be located directly between the CC-tag 10 and the metal layer.

[0106] The above describes several examples of the use of CC-label 10. Another example is using CC-label 10 (any of the types mentioned above) for consumables such as e-cigarettes, beverage capsules, etc. Figure 5 An example implementation of this is shown, in which the CC-tag 10 is incorporated into a part of the e-cigarette (e.g., a replaceable part, such as a plug or stick 510), while the reader (or, in this example, reader electrode 550) is placed in another part 540 of the e-cigarette. Thus, the reader can verify that it has a correct or legitimate replacement part present.

[0107] In this example, the conductive electrodes can be printed on or integrated into paper, such as the outer layer of an e-cigarette, and the CC-tag 10 can be integrated into a hollow acetate tube or polymer film filter. The reader electrode or electrode 550 can be integrated into the tip (ejector side) of the e-cigarette casing. For example, the reader electronics can be integrated into the same volume as the existing control electronics of the e-cigarette.

[0108] exist Figure 5In the example system, electrode 520 can also be placed on cigarette plug 510. However, CC-tag 10 can also operate without such an external electrode. Printed circuit board 505 can be used to mount various components of the system so that reader electrode 550 and associated contact 530 can be coupled to the reader (e.g., using RF communication). These parts of the system can be housed in housing 580 and electrically coupled (e.g., using USB connector 570) to provide data and power connectivity to a computer or microprocessor 560.

[0109] Figure 6a The figure shows in more detail how this CC-tag 10 is formed together with a cigarette or electronic cigarette (or other cylindrical object) 605. The figure schematically illustrates how a metal backplate or plate 620 adapts to the curved surface of the electronic cigarette 605 (e.g., a cylinder) and the insulating layer 610 separating this metal plate 620 from the CC-tag 10. The figure also shows the electrodes 630 of the reader surrounding the electronic cigarette 605 and the CC-tag 10.

[0110] Figure 6b This schematically illustrates the CC-label 10 (with similar characteristics to...). Figure 4 The metal back electrode or backplate metal layer shown is read within the annular metal reader electrode (550, 550') surrounding the cigarette or electronic cigarette 605. This electrode operates in a similar manner to those electrodes described above.

[0111] Such CC-tags 10 (i.e., those CC-tags that can be read by a single-sided or adjacent electrode reader) may be easier to read when applied to items such as labels, packaging, holograms, coatings (such as tablet coatings), other pharmaceutical products, and irregular or non-planar items. Figure 6b The diagram illustrates how the metal plate 620 extends beyond the substrate and / or metal pads of the CC-tag 10, such that one reader electrode 550' covers the metal plate 620 but not the remainder of the CC-tag 10, while another reader electrode 550 covers the remainder of the CC-tag 10. Thus, the metal plate capacitively couples a signal to a distant or opposite electrode of the CC-tag 10 (i.e., on its other side or the opposite side to where the reader electrode is located).

[0112] Although Figure 5 , Figure 6a and Figure 6b The specific CC-label 10 described throughout the specification is shown, but a similar configuration (i.e., electrode configuration) can be used for different capacitively coupled labels.

[0113] In example implementations, the metal plate may alternatively be formed from part or all of the article or object to which the tag is applied. For example, the article may be a metal or foil capsule, box, can, or carton containing the product. For example, the article may be disposable or reusable. This could be a beverage, coffee, or tea capsule with an aluminum body. In these examples, the article itself (or at least the metal container) may have the same function as the metal plate and be capacitively coupled to one electrode of the reader, thereby eliminating the need to place electrodes on either side of the CC-tag 10 and improving the usability of the CC-tag 10 when applied to conductive articles.

[0114] The problem being solved is, for example, integrating capacitive tags consisting of capacitor chips and electrodes into cigarette sticks for mass production.

[0115] The back electrode of the capacitive label can be incorporated into the paper, which is then rolled around the cigarette holder (e.g., by printing or interlacing metal conductors), and the capacitor chip is stamped onto the top of the electrode (adhesive can also be added to increase the fixing strength). The cigarette holder is then wrapped with paper around the assembly to fix the capacitor chip (CC-label) in place.

[0116] Such components have the advantage that they can be integrated into the current manufacturing process of cigarettes or e-cigarette sticks.

[0117] As an alternative, the back electrode can also be integrated into a hollow acetate tube, a cellulose acetate mouthpiece, or around a polymer membrane filter cooler (see below). The capacitor chip (i.e., any CC-label described throughout the specification) can then be stamped onto one of the three listed components. The chip's position is then held in place by the paper wound around the cigarette stick.

[0118] As an alternative, and in addition to integrating the electrode into one of the hollow acetate tube, cellulose acetate mouthpiece, polymer membrane filter cooler, and paper, a second electrode can also be integrated into the paper winding the cigarette stick, i.e., the paper for the mouthpiece, with the second electrode preferably only partially covering the first electrode. In such a configuration, the first electrode is in contact with or close to the back electrode of the capacitive chip (CC-tag), and the second electrode is in contact with or close to the top electrode of the capacitive chip, resulting in improved reading sensitivity of the capacitive tag (CC-tag).

[0119] As those skilled in the art will understand, the details of the above embodiments may be changed without departing from the scope of the invention as defined in the appended claims.

[0120] For example, CC-tags and readers can operate using standard Industrial, Scientific, and Medical (ISM) radio band frequencies (i.e., the frequency of the input RF signal). For instance, the operating frequency could be 13.56 MHz (or between 10 MHz and 15 MHz). CC-tags can operate at different frequencies (i.e., to avoid data signal interference). For example, readers can scan different frequencies.

[0121] Many combinations, modifications, or alterations of the features of the above embodiments will be apparent to those skilled in the art and are intended to form part of this invention. Any feature described that is specifically related to one embodiment or example can be adapted for any other embodiment by appropriate changes.

Claims

1. A capacitively coupled radio frequency identification (RFID) tag, comprising: A semiconductor substrate having a first plane and a second plane disposed away from the first plane; Non-overlapping metal pads are formed on the first plane of the semiconductor substrate, wherein the metal pads are the outermost metal layer of the first plane; A circuit, formed on the semiconductor substrate and electrically connected to the metal pads and a second plane of the semiconductor substrate, is configured to respond to an RF input signal by providing a data signal encoded by changing the impedance between the metal pads and the second plane of the semiconductor substrate; and A metal plate, wherein the metal plate extends beyond at least one edge of the metal pads and / or the semiconductor substrate. Wherein, when the metal plate extends beyond more than one edge of the metal pad and / or the semiconductor substrate, the extension beyond one edge is greater than the extension beyond one or more other edges.

2. The capacitively coupled RFID tag according to claim 1, wherein, The data signal is encoded by modulating the RF input signal by changing the impedance between the metal pad and the second plane of the semiconductor substrate.

3. The capacitively coupled RFID tag according to claim 1, wherein, The RF input signal is provided by an external reader.

4. The capacitively coupled RFID tag according to claim 1, wherein, The circuit is further configured to be powered by the RF input signal.

5. The capacitively coupled RFID tag according to claim 1, wherein, The circuit is further configured to decode a signal encoded within the RF input signal, and wherein the data signal is provided in response to the decoded signal.

6. The capacitively coupled RFID tag according to claim 1, wherein, The circuit modulates the RF input signal by changing its frequency, amplitude, and / or phase.

7. The capacitively coupled RFID tag according to claim 1, wherein, The circuit is formed on the second plane of the semiconductor substrate.

8. The capacitively coupled RFID tag according to claim 1, wherein, The circuit is configured to change the impedance between the metal pad and the second plane of the semiconductor substrate by applying a short circuit between the metal pad and the second plane of the semiconductor substrate.

9. The capacitively coupled RFID tag according to claim 1, wherein, The distance between the outer surface of the metal pad and the second plane of the semiconductor substrate is equal to or less than 100 μm.

10. The capacitively coupled RFID tag according to claim 1, wherein, The circuit is further configured to detect the presence of one or more other capacitively coupled RFID tags, and in response, to stop providing the data signal.

11. The capacitively coupled RFID tag according to claim 10, wherein, The circuit is configured to stop providing the data signal by applying a short circuit between the metal pad and the second plane of the semiconductor substrate.

12. The capacitively coupled RFID tag according to claim 10, wherein, The circuit is configured to stop providing data signals until the other one or more capacitively coupled RFID tags have provided their data signals.

13. The capacitively coupled RFID tag according to claim 10, wherein, The circuit is further configured to stop providing the data signal in accordance with an anti-collision protocol.

14. The capacitively coupled RFID tag according to claim 13, wherein, The anti-collision protocol is based on communication between the one or more capacitively coupled RFID tags, according to the following: Based on a predetermined response sequence, based on the negotiated response between the one or more capacitively coupled RFID tags, or based on a random number generator.

15. The capacitively coupled RFID tag according to claim 1, wherein, The first plane is parallel to the second plane.

16. The capacitively coupled RFID tag according to any of the preceding claims, wherein, The capacitively coupled RFID tag is flexible.

17. The capacitively coupled RFID tag of claim 1, further comprising an insulator bonded between the tag and the metal plate.

18. The capacitively coupled RFID tag according to claim 17, wherein, The insulator is bonded to the metal pads of the label.

19. The capacitively coupled RFID tag according to claim 17, wherein, The insulator is bonded to the second plane of the semiconductor substrate.

20. The capacitively coupled RFID tag according to claim 1, wherein, The metal plate is bent.

21. An article having an embedded capacitively coupled RFID tag according to any of the preceding claims.

22. The article according to claim 21, wherein, The surface of the item is parallel to the first plane of the capacitively coupled RFID tag.

23. The article of claim 21, wherein the article is formed of paper, wherein the article is formed of plastic material, and / or wherein the article is banknote, cigarette, e-cigarette, label, tablet, medicine, beverage capsule, coffee capsule, tea capsule, metal container, hologram, passport, ID card, tax invoice and / or legal document.

24. A method for communicating with a plurality of capacitively coupled RFID tags, the method comprising the following steps: The reader applies an RF input signal to the plurality of capacitively coupled RFID tags; One of the plurality of capacitively coupled RFID tags responds to the applied RF input by changing its impedance, and the changed impedance encodes the data signal. The reader detects a change in the RF input signal caused by altering the impedance of one of the plurality of capacitively coupled RFID tags, and the change encodes the data signal. The data signal is decoded by the reader based on the changes in the RF input signal; When one of the capacitively coupled RFID tags changes its impedance, the capacitively coupled RFID tags that do not respond reduce their impedance.

25. The method according to claim 24, wherein, The change in the RF input signal is a change in frequency, amplitude, and / or phase.

26. The method of claim 24, further comprising the step of: An anti-collision protocol is used to determine which of the plurality of capacitively coupled RFID tags responds to the radio frequency by changing its impedance.

27. The method according to claim 24, wherein, The multiple capacitively coupled RFID tags are stacked one on top of the other.

28. A computer program comprising program instructions that, when executed on a computer, cause the computer to perform the method according to any one of claims 24 to 27.

29. A computer-readable medium having a computer program according to claim 28.

30. A system comprising: One or more capacitively coupled RFID tags according to any one of claims 1 to 20; and The reader, including an RF signal generator and a decoder, is configured to decode the data signal.

31. The system according to claim 30, wherein, The capacitively coupled RFID tag is the capacitively coupled RFID tag according to claim 1, and wherein the reader further includes: A first electrode is configured to be aligned with the metal pads of the label and / or the semiconductor substrate; and The second electrode is configured to be partially aligned with the metal plate, which extends beyond at least one edge of the metal pad and / or the semiconductor substrate.

32. The system according to claim 31, wherein, The first electrode and the second electrode are bent.

33. The system according to claim 31, wherein, The metal plate is formed from metal packaging of boxes, cans, coffee capsules, tea capsules, or beverage capsules.

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